Long experience for the diagnosis and treatment of sporadic endolymphatic sac tumor in a single center
CLINICAL NEUROLOGY AND NEUROSURGERY
Authors: Guo, Fangzhou; Zhang, LiWei; Mo, LiGen
Abstract
Objectives: Sporadic endolymphatic sac tumor (ELST) is rare. The purpose of this study was to analyze the clinical feature and surgical outcome of a single-center series of sporadic ELSTs. Patients and Methods: We retrospectively reviewed all cases of sporadic ELSTs operated at the Tiantan hospital between 2010 and 2020. Results: Retrospective record revealed 14 patients with sporadic ELSTs who underwent surgical management. Serum VEGF(vascular endothelial growth factor)values of 6 patients were measured on admission, and the levels were all higher than normal(0 -160 ng/L, Enzyme-Linked ImmunoSorbent Assay). All patients underwent surgical treatments, and there was no significant difference in KPS before and after the operation(KPS = 88:88). The average maximum diameter of the tumor was 41 mm (range28 - 56 mm). After surgery, Two patients received radiation therapy, We did not encounter any case with metastatic dissemination. No deaths occurred during follow-up. Conclusion: ELST is defined as an aggressive or low-grade malignant tumor, with the characteristics of local recurrence and invasion of bone growth. Sporadic cases are common, and this rare tumor provides insight into the relationship between ELST and VHL syndrome. Early surgical resection can prevent or reduce the disability of auditory vestibular symptoms, and improve the chance of complete resection and retention of hearing. As far as possible complete resection of the tumor can prolong the disease-free survival of patients. Preoperative radiotherapy or stereotactic therapy cannot control tumor growth. Postoperative radiotherapy may have a positive effect on tumor control. The high expression of VEGF in patients may be related to tumor occurrence and development.
High-loading intrinsic active sites for ammonia synthesis using efficient single-atom catalyst: 2D tungsten-porphyrin sheet
APPLIED SURFACE SCIENCE
Authors: Yao, Xue; Chen, Zhi-Wen; Wang, Ya-Ru; Lang, Xing-You; Zhu, Yong-Fu; Gao, Wang; Jiang, Qing
Abstract
Single-atom catalysts (SACs) with active sites of transition metal-nitrogen (TMNx) centers are efficient for the electrochemical nitrogen reduction reaction (NRR), a sustainable strategy of ammonia synthesis, but the loading of active sites is relatively low due to the clustering of transition metal heteroatoms. Herein, 2D transition metal-porphyrin (TM-PP) sheets possessing high-loading intrinsic TMN4 centers were investigated to catalyze NRR using density functional theory (DFT). The results suggest that 5d TM-PP sheets are more efficient than 3d and 4d TM-PP sheets owing to their better capability of electron transfer, which is related to the screening effect induced by inner-shell electrons. Among them, as the most promising one, W-PP sheet possesses high mass loading of 38.33 wt% and low overpotential of 0.15 V, beneficial for catalyzing NRR with good selectivity.