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Palmitic acid coated magnetic nanoparticles (PA-Fe 3 O 4 MNPs) were employed in a simple and fast solid phase extraction procedure for the preconcentration of pesticides prior to GC-MS determination. The main factors influencing extraction efficiency including surfactant amount, sample pH, extraction time, desorption conditions and concentration of nanoparticles were optimized. Under the optimized conditions, a preconcentration factor of 1000 was achieved. Limits of detection and quantification in the range of 20-30 ng L À1 and 60-80 ng L À1 , respectively, were obtained for the proposed pesticides which include diazinon, pirimiphos methyl, aldrin-R, fenthion, chlorpyrifos, dicofol, triadimefon, heptachlorepoxide (Cis),

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Background Treatment of early-onset scoliosis (EOS) is still a challenge to patients, families, and surgeons. Previous studies have indicated that EOS patients are at high risk for complications following growth-friendly surgery. This study was performed to evaluate the results and complications of all-pedicle screw dual growing rod instrumentation in the treatment of EOS. Methods In an IRB-approved retrospective study, we searched the electronic medical records of our institution for all patients who underwent posterior spinal instrumentation for scoliosis between March 2014 and March 2017. Patients under the age of 10 at the time of surgery who were treated with a growth-friendly technique were then selected. Patients with incomplete records and less than 2 years of follow-up were excluded. Charts, operative notes, clinic visits, and radiographs were extracted. Radiographs were reviewed, and the main curve Cobb angle, thoracic kyphosis, pelvic tilt, pelvic incidence, sacral slope, and proximal junctional angles were measured. We specifically looked for any intra-operative or post-operative complications. Statistical analysis was performed to determine the risk factors of complications. Results A total of 42 patients with a mean age of 4.8 ± 2.1 years (range, 1.5–8 years) were included in the final analysis. Patients were followed for a median of 34 months (range, 24–55). The major curve was corrected from a mean of 42.9° ± 10.7° to 28.8° ± 9.6° at the latest follow-up. Proximal junctional angles and thoracic kyphosis increased significantly during the follow-up period (both P values < 0.001). A total of 7 complications (17%) were observed. Four patients (10%) developed superficial surgical site infections, all of which resolved with antibiotics and one round of surgical debridement. Three cases (7%) of proximal junctional kyphosis (PJK) were encountered during the study period, none of which required revision surgery. Pre-operative thoracic kyphosis was the only significant risk factor for the development of PJK. Conclusions Our findings suggest that in settings without access to magnetically controlled growing rods, dual growing rods with all-pedicle screw instrumentation is still a viable treatment strategy with comparable results and complications. The most common complications are infection and PJK, with the latter being associated with a larger pre-operative thoracic kyphosis.