1,679 research outputs found

    Unusual transport characteristics of nitrogen-doped single-walled carbon nanotubes

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    Electrical transport characteristics of nitrogen-doped single-walled carbon nanotubes (N-SWCNTs), in which the nitrogen dopant is believed to form a pyridinelike bonding configuration, are studied with the field effect transistor operations. Contrary to the expectation that the nitrogen atoms may induce a n -type doping, the electrical transports through our N-SWCNTs are either ambipolar in vacuum or p -type in air. Through the first-principles electronic structure calculations, we show that the nitrogen dopant indeed favors the pyridinelike configuration and the Fermi level of the pyridinelike N-SWCNT is almost at the intrinsic level.open01

    Bare-metal stents versus drug-eluting stents in large (≥3.5mm) single coronary artery: Angiographic and clinical outcomes at 6 months

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    SummaryBackgroundAlthough drug-eluting stents (DES) have been shown to dramatically reduce restenosis and improve the rate of event-free survival in large randomized trials, the benefit of DES appears to be limited to restenosis. In large arteries, it is not clear which type of stent is more superior in angiographic and clinical outcomes between DES and bare-metal stents (BMS). We compared the angiographic and clinical outcomes of DES versus BMS in large arteries (≥3.5mm).MethodTwo hundred and forty patients from March 2002 to March 2007 received stents; 196 patients were treated with DES (44.9% sirolimus-eluting stents; 43.9% paclitaxel-eluting stents; 11.2% zotarolimus-eluting stents) and 44 with cobalt–chromium BMS for single de novo lesions in a large vessel. All subjects received aspirin, clopidogrel, and/or cilostazol as the standard antiplatelet regimen. The angiographic and clinical outcomes were evaluated at 6 months.ResultsFor the baseline characteristics, there were no significant differences between the DES and BMS groups. In addition, for the initially implanted stent there was no difference in the length, stent diameter, and lesion site between the two groups. After 6 months, the follow-up angiogram showed that in-stent diameter restenosis and late loss was more common with BMS than DES (39±21% vs. 19±17%, p=0.007; 1.44±0.83mm vs. 0.62±0.58mm, p=0.009, respectively). However, the target-lesion revascularization/target-vessel revascularization, and total major adverse cardiac events showed no significant differences between the groups (5.3% vs. 3.6%, p=0.62; 5.3% vs. 4.6%, p=0.86, respectively).ConclusionThe DES and cobalt–chromium BMS placed in large coronary arteries showed equally favorable 6-month clinical outcomes, although the 6-month angiographic results appeared more favorable in the DES group than in the BMS group

    Comparative Study of the Outcomes of Unilateral Biportal Endoscopic Discectomy and Tubular Microdiscectomy Based on the Visual Analogue Scale, Oswestry Disability Index, and Short-form 36

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    Objective Unilateral biportal endoscopic (UBE) discectomy and tubular microdiscectomy (TMD) are widely practiced methods for treatment of lumbar disc herniation. Good clinical outcomes of these methods are reported in many papers, but there are a few comparative studies. This study reports the clinical outcomes of UBE and TMD as minimally invasive surgery methods for lumbar disc herniations and discusses the effectiveness of UBE. Methods Sixty-seven patients who had undergone single-level discectomy using one of two methods, UBE or TMD, underwent a prospective follow-up examination. Thirty-four of these patients underwent discectomy using UBE, and the remaining 33 patients underwent TMD. In addition to the traditional measures of outcome, the improvement of generic health-related quality of life and disease-specific measurements like Visual Analogue Scale (VAS) score, Short-form 36 (SF-36), and Oswestry Disability Index (ODI) were evaluated and compared. Results Sixty-seven patients with more than 6 months of post-operative follow-up evaluations were included. The mean improvements in the VAS scores for back pain and leg pain and ODI were 2.0, 3.7, and 26.5 for the UBE group and 1.6, 3.0, and 19.4 for the TMD group. The SF-36 physical health component subscale score improved from 35.4 pre-operatively to 54.8 at the last follow-up in the UBE group, and the mental health score improved from 43.5 to 55.1 (TMD group: from 34.9 to 54.3 and 44.2 to 57.1, respectively). Conclusion The clinical outcomes of the UBE group are comparable to those of the TMD group. The results indicate that UBE for lumbar disc herniation can be performed safely and effectively as a treatment modality

    Taxonomic review of the genus Nycteola Hübner (Lepidoptera, Nolidae) from Korea including potential invasive pests

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    The genus Nycteola Hübner has been mainly distributed in the Old World and usually feeds on Fagaceae and Salicaceae, but Myrtaceae and Juglandaceae have also been reported. In Korea, the number of this genus has been changed from four to three after 2007, but three or four species are listed confusingly up to now.The Japanese endemic species Nycteola dufayi Sugi, 1982 are firstly reported for the Continents with its brief biology. Additionally, Korean fauna of nycteolid species are reviewed

    Epidural Pneumatic Pseudocyst with Lumbar Radiculopathy: Two Case Reports and Review of the Literature

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    Intradiscal vacuum phenomenon is commonly shown in radiographic studies of the degenerative spine. In terms of pathophysiology, intradiscal gas migrates to the epidural space, and then it could compress neural tissues and lead to severe radicular pain and/or neurologic deficits. Herein, we report two patients with lumbar radiculopathy resulting from gas-containing pseudocysts at the L5-S1 space, including our treatment and literature review. One patient had been underwent L5-S1 partial laminectomy and removal of the gas-containing pseudocyst, and the other underwent right selective L5 root block. After the procedures, they didn’t have any remarkable complaints. In the present study, we suggest that surgical decompression may be effective in patients who were untreatable with conservative treatment
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