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We have used pulsed-slow-positron-beam-based positron lifetime spectroscopy to investigate the nature of acceptors and charge states of vacancy-type defects in low-energy proton-implanted 6H-SiC(H). We can infer from the temperature dependence of the lifetime spectra that neutral and negatively charged vacancy clusters exist in the track region. Depending on annealing, they give rise to positron lifetimes of 257±2, 281±4, and 345±2 ps, respectively. The 281 ps cluster likely has an ionization level near the middle of the band gap. By comparison with theory, the 257 and 280 ps are identified as (V[sub C]-V[sub Si])[sub 2] and (V[sub C]-V[sub Si])[sub 3] clusters, respectively. In addition, other acceptors of ionic type act as strong trapping centers at low temperature (T<150 K). Neutral monovacancy-like complexes are also detected with a lifetime of 160±2 after 900 °C annealing. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Objective: This study investigates the neuroprotective effects and functional recovery potential of Coenzyme Q10 (CoQ10) and ozone therapy in spinal cord injury (SCI)., Material and Methods: In this study, 40 female Sprague-Dawley rats were divided into 5 groups of 8. Surgical procedures induced spinal cord trauma in all groups, except the control group. The ozone group received 0.7 mg/kg rectal ozone daily for 7 days, starting 1 hour postspinal cord trauma. The CoQ10 group was administered 120 mg/kg CoQ10 orally once daily for 7 days, beginning 24 hours prior to trauma. The CoQ10 + ozone group received both treatments. Examinations included a modified Tarlov scale and inclined plane test on days 1, 3, 5, and 7. Malondialdehyde (MDA) analysis was conducted on serum samples, and assessments of caspase-3, Bcl-2, and Bax levels were performed on tissue samples. Additionally, a comprehensive examination analyzed histopathological and ultrastructural changes., Results: After SCI, there was a statistically significant increase in serum MDA, tissue caspase-3, and Bax levels (MDA P < 0.001, caspase-3 P < 0.001, Bax P = 0.003). In the CoQ10 + ozone group, serum MDA (P = 0.002), tissue caspase-3 (P = 0.001), and Bax (P = 0.030) levels were significantly lower compared to the trauma group. Tissue Bcl-2 levels were also significantly higher (P = 0.019). The combined treatment group demonstrated improved histopathological, ultrastructural, and neurological outcomes., Conclusions: This study shows that CoQ10 + ozone therapy in traumatic SCI demonstrates neuroprotective effects via antioxidant and antiapoptotic mechanisms. The positive effects on functional recovery are supported by data from biochemical, histopathological, ultrastructural, and neurological examinations., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Pituitary adenomas are slow-growing, benign intracranial tumors that can be characterized as functional (hormone-producing) or non-functional (non-hormone producing). Symptoms therefore arise from either endocrinologic abnormalities or mass effect on surrounding structures resulting in symptoms such as visual impairment and headache. In the last two decades, technical innovations have shifted surgical resection of such adenomas to endoscopic endonasal approaches. In this review, we describe the evolving approach to pituitary adenomas in the modern endoscopic era, including preoperative multidisciplinary review, relevant surgical anatomy, and a description of the technical nuances of standard and expanded approaches to the anterior skull base., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Vertebral hemangiomas are relatively common, but those causing spinal cord compression are rare. A 19-year-old male presented with thoracic back pain. The neurologic examination was normal and radiological examinations demonstrated an aggressive vertebral hemangioma centered within the T11 vertebral body. Damaged vertebral bone and soft tissue components of the mass were observed in the epidural space. Surgery was performed using a new technique involving radiofrequency ablation, injection of a hemostatic agent (FLOSEAL, Baxter, USA), and bone autograft placement in the affected vertebral body. There were no complications intra- or postoperatively, and the patient's back pain resolved completely during the postsurgical period. Bleeding is a serious issue in cases of aggressive vertebral hemangioma. This new technique provides improved bleeding control and strengthens the affected vertebra through autograft placement., (Copyright © 2018 Sociedad Española de Neurocirugía. Publicado por Elsevier España, S.L.U. All rights reserved.)

In the present article, we described a case of treating intractable pain from failed back surgery syndrome (FBSS) and multiple sclerosis (MS) after implantation of spinal cord stimulation (SCS) in a patient. We are reporting a case where SCS has been used for treating a patient with both FBSS and MS.

Objective: To determine whether recording of the activation potential may be used as an isolated criterion to guide catheter ablation of atriofascicular Mahaim fibers., Methods: We studied 6 patients (5 females, mean age of 26 +/- 7.3 years) with paroxysmal tachycardias with a wide QRS complex, whose electrophysiological study diagnosed atriofascicular Mahaim fibers. Mapping and catheter ablation were performed in sinus rhythm, guided only by the recording of the activation potential of the fiber., Results: Efficacy in ablation was achieved in all patients. The fibers were located in the right lateral region of the tricuspid ring in 3 patients, right posterolateral region in 2, and right anterolateral region in 1. A mean of 5.3 +/- 3 radiofrequency applications was performed. The mean fluoroscopy time was 46.6 +/- 25 minutes, and the mean duration of the procedure was 178.6 +/- 108 minutes. No complication occurred. In a mean 20-month follow-up, all patients were asymptomatic and receiving no antiarrhythmic drugs., Conclusion: Catheter ablation of Mahaim fibers may be performed with good safety and efficacy by mapping the activation potential of the tricuspid ring in sinus rhythm.