Enhanced Electrochemical Characteristics of the Glucose Oxidase Bioelectrode Constructed by Carboxyl-Functionalized Mesoporous Carbon

This research revealed the effect of carboxyl-functionalization on the mesoporous carbon (MC)-fixed glucose oxidase (GOx) for promoting the properties of bioelectrodes. It showed that the oxidation time, temperature and concentration, can significantly affect MC carboxylation. The condition of 2 M ammonium persulfate, 50 °C and 24 h was applied in the study for the successful addition of carboxyl groups to MC, analyzed by FTIR. The nitrogen adsorption isotherms, and X-ray diffraction analysis showed that the carboxylation process slightly changed the physical properties of MC and that the specific surface area and pore size were all well-maintained in MC-COOH. Electrochemical characteristics analysis showed that Nafion/GOx/MC-COOH presented better electrocatalytic activity with greater peak current intensity (1.13-fold of oxidation peak current and 4.98-fold of reduction peak current) compared to Nafion/GOx/MC. Anodic charge-transfer coefficients (α) of GOx/MC-COOH increased to 0.77, implying the favored anodic reaction. Furthermore, the GOx immobilization and enzyme activity in MC-COOH increased 140.72% and 252.74%, leading to the enhanced electroactive GOx surface coverage of Nafion/GOx/MC-COOH electrode (22.92% higher, 1.29 × 10−8 mol cm−2) than the control electrode. Results showed that carboxyl functionalization could increase the amount and activity of immobilized GOx, thereby improving the electrode properties

Enhanced Performance of Bioelectrodes Made with Amination-Modified Glucose Oxidase Immobilized on Carboxyl-Functionalized Ordered Mesoporous Carbon

This research reveals the improved performance of bioelectrodes made with amination-modified glucose oxidase (GOx-NH2) and carboxyl-functionalized mesoporous carbon (OMC-COOH). Results showed that when applied with 10 mM EDC amination, the functional groups of NH2 were successfully added to GOx, according to the analysis of 1H-NMR, elemental composition, and FTIR spectra. Moreover, after the aminated modification, increased enzyme immobilization (124.01 ± 1.49 mg GOx-NH2/g OMC-COOH; 2.77-fold increase) and enzyme activity (1.17-fold increase) were achieved, compared with those of non-modified GOx. Electrochemical analysis showed that aminated modification enhanced the peak current intensity of Nafion/GOx-NH2/OMC-COOH (1.32-fold increase), with increases in the charge transfer coefficient α (0.54), the apparent electron transfer rate constant ks (2.54 s−1), and the surface coverage Γ (2.91 × 10−9 mol·cm−2). Results showed that GOx-NH2/OMC-COOH exhibited impressive electro-activity and a favorable anodic reaction

Endovascular Treatment for Aneurysms Located in the Posterior Communicating Artery (PCoA) by the Swinging-Tail Technique: A Technical Note

Purposes: A stent-assisted coil (SAC) is a safe and effective treatment modality for some complex intracranial aneurysms, especially for wide neck aneurysms. However, some wide neck aneurysms with a tough angle and located in the posterior communicating artery (PCoA) are challenging to treat with a SAC. This study aimed to examine and discuss the swinging-tail technique for treating wide neck aneurysms located in the PCoA using a SAC by Prof. Lv. Materials and Methods: We retrospectively reviewed our institutional clinical database and identified nine patients with neck aneurysms located in the PCoA, and these patients underwent the swinging-tail technique by Prof. Lv, which is a novel technique of releasing a stent, from June 2016 to September 2021. Results: In this study, nine patients underwent SAC treatment using the swinging-tail technique by Prof. Lv. Aneurysmal complete occlusion was observed in every patient without any complications, as shown by immediate postoperative angiography. Additionally, the modified Rankin scale was monitored for clinical outcomes in the follow-up. One patient died postoperatively due to severe SAH with an intraventricular hemorrhage. Four of nine patients underwent imaging follow-up, demonstrating the complete occlusion of aneurysms; eight patients underwent clinical follow-up and achieved a favorable clinical outcome (modified Rankin scale score: 0–2). Conclusion: The SAC treatment for wide neck aneurysms located in the PCoA can be challenging for operators because of the specific location, resulting in inadequate vessel wall apposition by antegrade stenting via the ipsilateral vessel. In this circumstance, the swinging-tail technique may be a feasible and effective choice

Cavernous region dural fistulas with venous drainage of laterocavernous sinus

Background : We present our findings concerning the laterocavernous sinus (LCS) drainage of cavernous region dural fistulas, focusing our attention on the anatomy of LCS as it may have important implications in the treatment. Patients and Methods : Thirty-one consecutive patients with cavernous region dural fistulas treated endovascularly between 2005 and 2008 were reviewed. Five patients had angiographic features such as cavernous region dural fistulas draining with superficial middle cerebral vein (SMCV) via LCS. Clinical records of these 5 patients were focused upon to determine their presenting symptoms, angiographic features, endovascular treatments and clinical outcomes. Results : Among 31 cases of cavernous dural arteriovenous fistula (DAVF), 5 (16%) cases with leptomeningeal veins [SMCV, petrosal vein] reflux via LCS were noted. The 5 cavernous region dural fistulas were defined as Cognard type III and Barrow type A (1/5), B (1/5), C (1/5) and D (2/5). All 5 patients underwent immediate obliteration of the cavernous region dural fistulas in 3 sessions of transarterial and 2 sessions of transvenous embolization. An angiographic obliteration and clinical cure was achieved in all patients. We encountered one minor complication of local hair loss induced by X-ray radiation. A complete resolution of the initial presenting symptoms was observed within a few days to weeks. Six-month follow-up angiogram in 5 patients showed obliteration and no recanalization of CCF. Conclusion : It is very important to diagnose the presence of laterocavernous sinus in dural arteriovenous fistulas during diagnostic angiography. It is believed that the knowledge of the existence of laterocavernous sinus might be relevant for the understanding and treatment of dural fistulas involving the cavernous sinus and its lateral wall