Nano crystals of γ-Fe 2 O 3 (maghemite) were synthesized by emulsion precipitation method using kerosene as oil phase, SPAN-80 (sorbitane monooleate) as the surfactant and sodium hydroxide as the precipitating agent. The characterization of the samples by FTIR (Fourier transform infra-red) and XRD (X-ray diffraction) techniques confirmed the formation of γ-Fe 2 O 3 (maghemite). Analysis by SEM (scanning electron microscope) and TEM (transmission electron microscope) was carried out to study the morphology and particle size. The as prepared samples contained inverse spinel cubic phase maghemite. Effect of initial iron concentration on crystallite size of maghemite showed that it decreased with the decrease in initial iron concentration. Transformation of γ-Fe 2 O 3 to α-Fe 2 O 3 (hematite) was studied by calcining the precursor in the temperature range of 500 to 850°C. Formation/transformation of phases at different temperatures was confirmed by FTIR and XRD studies. Images, obtained by SEM and TEM showed the morphology and nanocrystal formation of hematite. Room temperature rheological behaviour of the synthesized α-Fe 2 O 3 nano powder has been studied.
Purpose This meta-analysis aims to systematically assess and quantitatively pool the best clinical evidence for migration percentage (MP) and odds ratio (OR) for recurrence/reoperation following treatment for hip subluxation in children with cerebral palsy (CP), including Botulinum Toxin A (BNT-A), soft-tissue lengthening and osteotomies Methods Pubmed, EMBASE and Cochrane were systematically searched from between 1 January 1953 and 11 January 2017 inclusive for studies reporting resubluxation/reoperation rates, and/or MP following treatment for hip subluxation in children with CP. The primary outcome was odds of resubluxation/reoperation. The secondary outcome was change in MP. Studies were graded for quality using the Newcastle Ottawa Scale. This meta-analysis was performed and reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results A total of 14 studies were included in analysis of odds of resubluxation/reoperation and 24 studies were included in analysis of MP. The OR for resubluxation/reoperation was lower for combined osteotomies compared with femoral (OR = 0.49; 95% confidence interval (CI) 0.25 to 0.98) and for femoral osteotomy compared to soft-tissue procedures (OR = 0.20; 95% CI 0.07 to 0.61). There was no difference in odds of recurrence/reoperation between pelvic and femoral osteotomies (OR = 2.27; 95% CI 0.37 to 13.88). Combined osteotomies provided the greatest improvement in MP, while BoNT-A showed no improvement in MP. Conclusion Resubluxation/reoperation rates are high; management with osteotomies is preferred to soft-tissue procedures alone in preventing resubluxation/reoperation. This meta-analysis is limited by the observational nature and small sample sizes of many of the included studies, with their inherent risk of bias and lack of homogeneity of patient characteristics at baseline. It is possible that with larger and higher quality studies, the results and conclusions of this analysis may be altered.
Purpose: Clinical changes are best evaluated with standardized, validated outcomes, including both patient-reported outcome measures and surgeon-reported outcome measures (PROMs and SROMs). The purpose of this study was to describe the spectrum of outcome measures used in pediatric orthopaedic publications over the past 10 years and to determine the proportion that are in fact age-appropriate, validated, and appropriately applied in terms of condition and population. Methods: The Journal of Bone and Joint Surgery, The Bone and Joint Journal, Journal of Pediatric Orthopaedics A and B, and Journal of Children’s Orthopaedics were systematically searched for studies including children aged 18 and below, over a 10-year period from January 2005 to December 2014. Economic evaluations, letters, editorials, review articles, and clinical guidelines were excluded. SROMs and PROMs used were extracted, as were details on subject age and condition for which they were used. Each outcome scale was assessed for validity, and the proportion of scales used appropriately was calculated. Cochrane-Armitage test of trend was used to determine changes in PROM and SROM utilization over the study period. Results: A total of 4614 articles were identified, of which 2251 met inclusion and exclusion criteria. In total, 259 (11.5%) of studies used a PROM, whereas 326 (14.5%) used a SROM. A total of 230 different outcome scales were identified; 115 were patient reported and 115 were surgeon reported. However, only 18.7% of SROMs and 38.3% of PROMs were applied to an age and disease-appropriate demographic. Overall, there was a significant increase in the overall utilization of PROMs during the study period (P=0.004), but no corresponding increase in pediatric-validated PROMs (P=0.164). SROM utilization did not significantly change over the study period (P=0.337). Conclusions: Within the field of pediatric orthopaedics, an expansive variety of outcome scales are used, many of which have not been validated in children. Improved uniformity in reporting of outcomes and use of disease and age-validated outcomes scales is essential to improve multicenter research collaboration and data quality to generate appropriate evidence-based conclusions and treatment strategies in pediatric orthopaedics. Level of Evidence: Level IV—systematic review.
Congenital tracheomalacia, resulting from incomplete tracheal cartilage development, is a relatively common birth defect that severely impairs breathing in neonates. Mutations in the Hedgehog (HH) pathway and downstream Gli transcription factors are associated with tracheomalacia in patients and mouse models; however, the underlying molecular mechanisms are unclear. Using multiple HH/Gli mouse mutants, including one that mimics Pallister–Hall Syndrome, we show that excessive Gli repressor activity prevents specification of tracheal chondrocytes. Lineage-tracing experiments show that Sox9+ chondrocytes arise from HH-responsive splanchnic mesoderm in the fetal foregut that expresses the transcription factor Foxf1. Disrupted HH/Gli signaling results in (1) loss of Foxf1, which in turn is required to support Sox9+ chondrocyte progenitors, and (2) a dramatic reduction in Rspo2, a secreted ligand that potentiates Wnt signaling known to be required for chondrogenesis. These results reveal an HH-Foxf1-Rspo2 signaling axis that governs tracheal cartilage development and informs the etiology of tracheomalacia.This article has an associated First Person interview with the first author of the paper.
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