Tuned Transport Path of Perovskite MAPbI3 -based Memristor Structure.

In this study, the features of resistive random access memory (RRAM) employing a straightforward Cr/MAPbI3 /FTO three-layer structure have been examined and clarified. The device displays various resistance switching (RS) behavior at various sweep voltages between 0.5 and 5 V. The RS effect has a conversion in the direction of the SET and RESET processes during sweeping for a number of cycles at a specific voltage. The directional change of the RS processes corresponds to the dominant transition between the generation/recombination of iodide ion and vacancy in the MAPbI3 perovskite layer and the electrochemical metallization of the Cr electrode under the influence of an electric field, which results in the conductive filament (CF) formation/rupture. At each stage, these processes are controlled by specific charge conduction mechanisms, including Ohmic conduction, space-charge-limited conduction (SCLC), and variable-range hopping (VRH). By identifying the biased voltage and the quantity of voltage sweep cycles, one can take a new approach to control or modulate the pathways for effective charge transport. This new approach is made possible by an understanding of the RS characteristics and the corresponding mechanisms causing the variation of RS behavior in the structure.

Surgery and radiation management for chondrosarcoma of the temporo-mandibular joint: A Vietnamese case report.

INTRODUCTION: Chondrosarcoma is a malignant tumor originated from cartilage cells. The most common sites of chondrosarcoma are pelvis, femur and ribs. The temporo-mandibular joint (TMJ) chondrosarcoma is extremely rare, with approximately 30 cases reported in worldwide. PRESENTATION OF CASE: In this report, we present a case of chondrosarcoma in the left TMJ, which was successfully treated with surgery and radiation therapy. A 47 year-old women was admitted to our hospital with a mass in left pre-auricular region. On examination and para-clinical test results, the initial diagnosis was parotid gland cancer. In operation, the lesion was a mass originating from the left TMJ. Tumor resection was performed with close margin. The post-operative pathological result was well-differentiated chondrosarcoma. She was indicated adjuvant radiation therapy due to inadequate surgical therapy. There was no evidence of recurrence after 6 months follow-up. CONCLUSION: The TMJ chondrosarcoma is needed to distinguish from other diseases especially parotid gland tumor. Surgery and adjuvant radiation therapy are standard care with the aim of preserving joint function.