In-situelectrochemical polymerization of aniline on flexible conductive substrates for supercapacitors and non-enzymatic ascorbic acid sensors.

Polyaniline, as a kind of conductive polymer with commercial application prospects, is still under researches in its synthesis and applications. In this work, polyaniline was fabricated on flexible substrates including carbon cloths and polyethylene naphthalate byin situelectropolymerization method. The synthesized flexible electrodes were characterized by scanning electron microscopy, High resolution transmission electron microscope, atomic force microscope, Fourier transform infrared, x-ray diffraction, and x-ray photoelectron spectroscopy. Owing to the conductivity and the reversible redox property, the polyaniline/carbon cloth electrodes show excellent properties such as decent supercapacitor performance and good detection capability toward ascorbic acid. As supercapacitors, the electrodes exhibit a specific capacitance as high as 776 F g-1at a current density of 1 A g-1and a long cycle life of 20 000 times in the three-electrode system. As ascorbic acid sensors, the flexible electrodes demonstrate stable response to ascorbic acid in the range of 1-3000µM with an outstanding sensitivity (4228µA mM-1cm-2), low detection limit (1µM), and a fast response time. This work holds promise for high-performance and low-cost flexible electrodes for both supercapacitors and non-enzymatic ascorbic acid sensors, and may inspire inventions of self-powered electrochemical sensor.

An anomalous Hall effect in edge-bonded monolayer graphene.

An anomalous Hall effect (AHE) is usually presumed to be absent in pristine graphene due to its diamagnetism. In this work, we report that a gate-tunable Hall resistance Rxy can be obtained in edge-bonded monolayer graphene without an external magnetic field. In a perpendicular magnetic field, Rxy consists of a sum of two terms: one from the ordinary Hall effect and the other from the AHE (RAHE). Plateaus of Rxy ∼ 0.94h/3e2 and RAHE ∼ 0.88h/3e2 have been observed while the longitudinal resistance Rxx decreases at a temperature of 2 K, which are indications of the quantum version of the AHE. At a temperature of 300 K, Rxx shows a positive, giant magnetoresistance of ∼177% and RAHE still has a value of ∼400 Ω. These observations indicate the existence of a long-range ferromagnetic order in pristine graphene, which may lead to new applications in pure carbon-based spintronics.

Surface-Confined SnS2 @C@rGO as High-Performance Anode Materials for Sodium- and Potassium-Ion Batteries.

Potassium- (PIBs) and sodium-ion batteries (SIBs) are emerging as promising alternatives to lithium-ion batteries owing to the low cost and abundance of K and Na resources. However, the large radius of K+ and Na+ lead to sluggish kinetics and relatively large volume variations. Herein, a surface-confined strategy is developed to restrain SnS2 in self-generated hierarchically porous carbon networks with an in situ reduced graphene oxide (rGO) shell (SnS2 @C@rGO). The as-prepared SnS2 @C@rGO electrode delivers high reversible capacity (721.9 mAh g-1 at 0.05 A g-1 ) and superior rate capability (397.4 mAh g-1 at 2.0 A g-1 ) as the anode material of SIB. Furthermore, a reversible capacity of 499.4 mAh g-1 (0.05 A g-1 ) and a cycling stability with 298.1 mAh g-1 after 500 cycles at a current density of 0.5 A g-1 were achieved in PIBs, surpassing most of the reported non-carbonaceous anode materials. Additionally, the electrochemical reactions between SnS2 and K+ were investigated and elucidated.

[Investigation of bile duct injury after transcatheter arterial chemoembolization].

OBJECTIVE: To investigate the image findings of bile duct injury after transcatheter arterial chemoembolization (TACE) for hepatic malignancy. METHODS: During the past 3 years, 1240 patients with different hepatic malignancies had undergone a total of 2680 TACE procedures. Eighteen patients (1.4%) developed bile duct injuries from 3 weeks to 3 months after TACE. All of the 18 patients received follow-up CT and ultra-sonography, 14 MRI and 15 digital subtract angiography (DSA). The image data was retrospectively reviewed, with the potential predisposing factors correlated to TACE-induced bile duct injury. RESULTS: TACE-induced bile duct injuries developed in 13 of 148 patients with liver metastasis (8.8%), 5 of 1092 patients with hepatocellular carcinoma (HCC) (0.5%). On image examination, focal peripheral intrahepatic bile duct dilatation was detected in 4 cases, multiple bile duct dilatations with segmental or sub-segmental distribution in 8, and a large lobular cystic lesion or biloma in 6 cases, and progressive atrophy of the corresponding hepatic parenchyma in 6 patients in whom the TACE induced-bile injury developed at different intervals after TACE. The incidence of bile duct injury was higher in non-cirrhotic patients with metastatic liver lesions than in patients with hepatocellular carcinoma associated with cirrhosis (P < 0.01), and it was also higher in patients using an emulsion of lipiodol-cisplatin or carboplatin than in patients using other emboliging agents (P < 0.01). The incidence was higher either in patients with hypovascular lesions than in patients with hypervascular lesions (P < 0.05). CONCLUSION: Biliary abnormalities, including focal and multiple intrahepatic bile duct dilatation, and cystic lesion or biloma, may develop and can be detected during the follow-up examination imaging in patients with hepatic malignancy after TACE. Noncirrhotic liver and intact function, due to the lack of peri-biliany collateral circulation, are the significant predisposing factors to the development of TACE-induced bile duct injury.

[Treatment of celiac and mesenteric arteries stenoses with interventional radiologic techniques].

OBJECTIVE: To evaluate the safety and efficacy of the interventional techniques for management of celiac and mesenteric arteries stenoses. METHODS: Eight patients with celiac artery (CA) or superior mesenteric artery (SMA) focal stenotic lesions were treated with percutaneous transluminal balloon angioplasty (PTA) and stent placement. CA stenosis was present in 2 patients, SMA stenosis was present in 4, and both CA and SMA were involved in 2 patients. Postprandial pain was present in 4 patients, an epigastric bruit was present in 5. All patients presented with weight loss averaging 8 kg. The causes of the stenoses were atheroscleroses in 7 patients, median arcuate ligament syndrome (MALS) involvement of the CA in 1 patient. RESULTS: PTA and stent placement was technically successful in the 8 patients. Three patients underwent stent placement in CA, 5 patients in SMA. Seven patients were treated with 1 stent, one was treated with 2 stents. The post-procedural arteriograms showed good dilation of the stenotic lesions in all patients. The puncture site hematoma occurred in 2 patients without severe consequences. Complete alleviation of abdominal pain occurred in 5 patients, significant improvement in 2, and no improvement in 1 patient. At three months after the procedures, weights were regained in 6 patients. Clinical follow-up was available in all 8 patients, with a mean follow-up of 42 months (median 28 months, range 6 to 72 months). Follow-up Doppler ultrasound examinations showed normal flow patterns, without evidences of re-stenosis in the stenting arteries. Five patients remained asymptomatic, one patient had intermittent abdominal pain even the stenting SMA to be patent. Two patients respectively died of unrelated CA/SMA stenosis in 14 and 24 months after the treatment. CONCLUSION: PTA and stent placement are safe and effective methods for treatment of chronic CA and SMA focal stenoses, especially useful for these patients with a high surgical risk.

Experience of minimally invasive treatment in 520 patients with intracranial aneurysms.

OBJECTIVE: To summarize the experience of minimally invasive treatment in 520 patients with intracranial aneurysms on a retrospective study. METHODS: The measures used in the treatment of 520 patients were reviewed in terms of timing of surgery, induced-hypotensive anesthesia, brain protection combined with temporal occlusion of the feeding artery, external drainage of CSF, dynamic monitoring of intracranial pressure, blood flow velocity, serum osmolality and CT scanning, anti-vasospasm therapy as well as selected interventional endovascular embolization of aneurysms. RESULTS: Of the 520 patients, 485 were treated with either direct clipping or endovascular embolization and 35 patients were treated non-surgically. In 449 patients undergoing direct clipping and 36 undergoing endovascular embolization, intraoperative rupture of aneurysm occurred in 27 (6.0%) and 0%, respectively. Death occurred in 13 (2.6%), hemiplegia in 8 (1.6%), and vegetative state in 2 (0.4%). The operative mortality of direct clipping was 3.8% in 210 patients before 1990 and 1.8% in 275 patients after 1990 (36 patients undergoing endovascular embolization, the operative mortality was 0%). CONCLUSION: The outcome of patients with intacranial aneurysms can be markedly improved and the operative mortality can be lowered by minimally invasive treatment.

[Treatment of acquired arteriovenous fistulas with interventional minimally invasive techniques].

OBJECTIVE: To evaluate the efficacy and safety of the interventional techniques for treatment of acquired arteriovenous fistulas (AVF). METHODS: Ten patients with acquired AVFs, including 4 with renal AVF, 3 with iliac AVF, and 3 with subclavian AVF, were treated with interventional procedures. The etiological factors of the AVFs were penetrating trauma in 5 cases, iatrogenic injury in 3, malignancy in 1, and intestine Crohn's disease in 1. The patients presented with peripheral venous hypertension (n = 6), local bruit (n = 10), cardiac overload (n = 10), the right cardiac failure (n = 2), and hematuria (n = 4). Three patients underwent transcatheter super-selective coils embolization and 7 underwent stent-graft placement in the involved arteries. RESULTS: The technical success was achieved in all cases. Completion angiography documented complete exclusion of the fistulas. Minor complications occurred in 3 patients, but without significant consequences. The patients experienced immediate relief of the limb swelling, peripheral venous hyperemia, and tachycardia. The local bruit was disappeared. The cardiac overload conditions were improved significantly, which was confirmed by ultrasound scan. Renal function tests in patients with renal AVF were stable. Radioactive isotopic scan revealed that the function was preserved in the treated kidney in two patients using stent-graft placement in the renal arteries. Follow-up time ranged from 6 months to 6 years. Three patients respectively died of unrelated AVF diseases in 6, 9, and 14 months after the treatment. Re-intervention with an another stent-graft placement was performed on 2 patients with recurrence of the AVF respectively at 3 weeks and two months after the procedures. The minor stenosis was found in stent-graft 2 of patients on the follow-up angiography respectively at 6 and 8 months after the treatment. Seven patients are still alive and in good condition without further intervention. CONCLUSIONS: Minimally invasive interventional procedures, including super-selective embolization and stent-graft exclusion, are safe and effective in the treatment of acquired arteriovenous fistulas.