The Influence of Boron (B), Tin (Sn), Copper (Cu), and Manganese (Mn) on the Microstructure of Spheroidal Graphite Irons

Most spheroidal graphite irons (SGIs) have a matrix consisting of ferrite, pearlite, or a mix of the two. To achieve the desired matrix composition, pearlite promoters such as Mn, Cu, or Sn, are added to the molten metal. Among these elements, Sn is the most potent pearlite promoter. However, each has a different impact on the solidification, graphite precipitation, eutectoid transformation, and ultimately the final structure of the material. Research has shown that B promotes ferrite in fully pearlitic grades where Cu and Mn were used to promote pearlite. The present work investigates the effect of B in SGI with additions of Sn, Cu, and Mn, and the effects of varying amounts of the different pearlite promoters on the matrix composition. The results show that Mn alone at levels of approximately 0.9 wt% is not enough to promote a fully pearlitic matrix, while 0.5 wt% Cu combined with 0.67 wt% Mn is sufficient. Likewise, a fully pearlitic microstructure can be obtained by alloying with 0.06 wt% Sn and 0.67 wt% Mn. B was found to promote ferrite in fully pearlitic SGI alloyed with Sn or Cu. However, in the absence of those elements, B promoted pearlite when alloyed with just Mn. Graphite protrusions were observed on the graphite nodule surface only for B-added alloys with Sn and Cu. In these cases, it is believed B promotes ferrite by changing the growth mechanism of graphite after solidification from spherical to lamellar. However, a different graphite morphology is observed when B is added with just Mn. Thermal analysis data is in agreement with the microstructural observations regarding the ferrite promoting effect of B

International Consensus Statement on Rhinology and Allergy: Rhinosinusitis

Background: The 5 years since the publication of the first International Consensus Statement on Allergy and Rhinology: Rhinosinusitis (ICAR‐RS) has witnessed foundational progress in our understanding and treatment of rhinologic disease. These advances are reflected within the more than 40 new topics covered within the ICAR‐RS‐2021 as well as updates to the original 140 topics. This executive summary consolidates the evidence‐based findings of the document. Methods: ICAR‐RS presents over 180 topics in the forms of evidence‐based reviews with recommendations (EBRRs), evidence‐based reviews, and literature reviews. The highest grade structured recommendations of the EBRR sections are summarized in this executive summary. Results: ICAR‐RS‐2021 covers 22 topics regarding the medical management of RS, which are grade A/B and are presented in the executive summary. Additionally, 4 topics regarding the surgical management of RS are grade A/B and are presented in the executive summary. Finally, a comprehensive evidence‐based management algorithm is provided. Conclusion: This ICAR‐RS‐2021 executive summary provides a compilation of the evidence‐based recommendations for medical and surgical treatment of the most common forms of RS

Topical Levobupivacaine Efficacy in Pain Control after Functional Endoscopic Sinus Surgery

WOS: 000330515100022PubMed: 24005134Objective. The aim of this study was to find out the efficacy of a polyvinyl alcohol (PVA) sponge (Merocel Kennedy; Medtronic Xomed, Jacksonville, Florida) sinus pack soaked with levobupivacaine hydrochloride to control postoperative pain and analgesic need following functional endoscopic sinus surgery (FESS). Study Design. The study was designed as a prospective, double-blind, randomized, controlled study. Forty-one patients who underwent FESS were included in the analysis. Setting. A tertiary referral hospital in Turkey. Materials and Methods. Patients who underwent FESS were divided into 2 groups. The PVA sponge sinus packs were soaked with 5 mL of levobupivacaine hydrochloride (chirocaine 25 mg/10 mL; Abbott, Nycomed Pharma AS, Elverum, Norway) in group I and with 5 mL of saline in group II. Main Outcome Measures. Postoperative pain levels were recorded using a visual analog scale (VAS score, 0-100) at 30 minutes and 1, 2, 8, 12, and 24 hours. Results. There were no statistically significant differences between groups regarding age, sex, and American Society of Anesthesiologists status. Postoperative VAS values at 30 minutes and 1, 2, 8, 12, and 24 hours were significantly lower in group I than in group II (P < .05). Supplemental analgesia amount was significantly lower in group I than in group II (P = .003). Conclusion. Using levobupivacaine-soaked PVA sponge sinus packs after FESS is an effective, easy, and quick method to control postoperative pain, and it improves patient comfort and tolerability

Postoperative Management of Pediatric Sinusitis

Postoperative management is essential to maximizing the clinical outcomes following pediatric sinus surgery. This chapter examines the current approach to postoperative care following functional endoscopic sinus surgery in the pediatric population. Nasal saline irrigations are a mainstay for many surgeons with a high efficacy and tolerability in children. Additional therapies include saline sprays, topical antibiotics, and topical steroids. Systemic forms of steroids or antibiotics may be considered in the short-term recovery period to help with healing, particularly in moderate to severe disease. Additionally, chronic rhinosinusitis with nasal polyps showed increased response rates postoperatively to systemic steroids. Unlike in adult populations, postoperative debridement is unnecessary in most pediatric cases with no demonstrated improvement in surgical success rates in patients who do not get debridement compared to those who get a second look with debridement. Postoperative care and continuing medical management should be individualized to the patient’s comorbidities and underlying etiology of chronic sinusitis. Cystic fibrosis requires special consideration with saline irrigations, corticosteroids, and antibiotics, with consideration of dornase alfa and gene therapy. The chapter concludes that functional endoscopic sinus surgery has been an effective tool in treating pediatric sinusitis refractory to medical therapy, with postoperative care recognized as having utmost importance to bridge surgical therapy with continued medical treatment for pediatric chronic rhinosinusitis

Endoscopic Sinus Surgery in Chronic Rhinosinusitis and Nasal Polyposis: A Comparative Study

Nasal polyposis are common presentations in patients of chronic rhinosinusitis and are considered to be associated with more severe forms of disease with poor treatment outcome. The presentation and treatment outcome after endoscopic sinus surgery in patients of chronic rhinosinusitis and nasal polyposis have been analysed in this study. A prospective analysis of 90 patients of chronic rhinosinusitis who were classified into two groups depending on presence and absence of nasal polyps was performed in the study. The two groups were evaluated using subjective (patient complaints) and objective (computed tomography scan and endoscopy scores) criteria. Preoperative data were compared with data obtained 12 months post endoscopic sinus surgery. The study included 38 patients of chronic rhinosinusitis and 52 patients of nasal polyps. The patients of nasal polyp group presented with increased severity of symptoms of nasal blockage, nasal discharge and reduced sense of smell as compared to the chronic rhinosinusitis group who had significantly higher presentation of headache and facial pain. The preoperative CT scan revealed significantly higher bilateral disease with increased involvement of multiple sinuses in nasal polyp group. Post endoscopic sinus surgery both the groups showed significant improvement in their symptoms with the nasal polyp group demonstrating reduction in improvement on 1 year follow up. In our study we have found the patients with chronic rhinosinusitis and nasal polyp have varied severity of symptoms with the nasal polyp group having higher nasal symptoms and increased severity as compared to chronic rhinosinusitis group. Though the universal rationale of management by adequate drainage and ventilation of sinus is similar in both groups, there is a reduction in both objective and subjective scores during 1 year follow up in the nasal polyp group