RESUMEN
A giant cell tumor (GCT) of the bone is characteristically found in skeletally mature patients. The tumor is rare in pediatric patients, and incidence reported in literature varies from 1.8% to 10.6%. We performed a retrospective study addressing symptoms, treatment, and outcome in pediatric patients who were diagnosed with GCT between March 1997 and January 2015 at our hospital. Fourteen (11.1%) of 126 surgically treated patients with histologically proven GCT were <19 years of age. We confirmed skeletal maturity using magnetic resonance imaging (MRI). Fourteen patients from 8 to 19 years old were identified. Sixteen lesions (76.2%) were found in long bones and 5 lesions (23.8%) in short bones. The most common site was around the knee in 8 patients (38%). GCTs mostly occur at the epi-metaphysis in 11 patients (52.3%). Regardless of the openness of epiphyseal plate, we observed GCT of bone in the epiphysis. Further study will be needed to prove the association between the presence of epiphyseal plate and location of tumor. Three patients (21.4%) had multicentric lesions, and four patients (28.5%) had local recurrence. Multicentric giant cell tumor and local recurrence occur more often in pediatric patients. The characteristics of GCT in pediatric patients do not differ from what is reported for GCT in adults.
RESUMEN
Two-dimensional transitional metal halides have recently attracted significant attention due to their thickness-dependent and electrostatically tunable magnetic properties. However, this class of materials is highly reactive chemically, which leads to irreversible degradation and catastrophic dissolution within seconds in ambient conditions, severely limiting subsequent characterization, processing, and applications. Here, we impart long-term ambient stability to the prototypical transition metal halide CrI3 by assembling a noncovalent organic buffer layer, perylenetetracarboxylic dianhydride (PTCDA), which templates subsequent atomic layer deposition (ALD) of alumina. X-ray photoelectron spectroscopy demonstrates the necessity of the noncovalent organic buffer layer since the CrI3 undergoes deleterious surface reactions with the ALD precursors in the absence of PTCDA. This organic-inorganic encapsulation scheme preserves the long-range magnetic ordering in CrI3 down to the monolayer limit as confirmed by magneto-optical Kerr effect measurements. Furthermore, we demonstrate field-effect transistors, photodetectors, and optothermal measurements of CrI3 thermal conductivity in ambient conditions.
