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Now showing items 97 - 112 of 134

  • Concurrence of Fahr's disease and brain tumor:A case report and review of the literature"

    Piao, Yueshan   Ling, Feng   Xu, Geng  

    Fahr's disease is a rare entity characterized by abnormal calcification in the bilateral basal ganglion regions and cerebellum. Concurrence of Fahr's disease with brain tumor is associated with an even lower incidence; the present study describes the fifth such case, in which a 32-year-old female presented with a 1-month history of headache and unsteady walking. Pathology and imaging studies resulted in a diagnosis of low-grade astrocytoma with calcified deposition. The patient recovered uneventfully. Following a review of the literature, several similarities among the reported cases were revealed. Patients were relatively young at the onset of the disease. The pathological diagnosis for all brain tumors was astrocytoma. The cerebellum was the predominant location of the brain tumor. The imaging studies of these cerebral astrocytomas were almost identical, with a cystic glioma occurring adjacent to a neighboring calcified dentate nucleus. Furthermore, the development of astrocytoma in the bilateral cerebellar hemisphere was not uncommon, which warrants close follow-up for these patients.
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  • Parallel Discrete Complex Image Method for Barnes-Hut Accelerated Capacitance Extraction in Multilayered Substrates

    Butt, Khalid   Jeffrey, Ian   Ling, Feng   Okhmatovski, Vladimir  

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  • Earth Observation and Machine Learning to Meet Sustainable Development Goal 8.7: Mapping Sites Associated with Slavery from Space

    Foody, Giles   Ling, Feng   Boyd, Doreen   Li, Xiaodong   Wardlaw, Jessica  

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  • DNA recombination-initiation plays a role in the extremely biased inheritance of yeast [rho(-)] mitochondrial DNA that contains the replication origin ori5

    Ling, Feng   Hori, Akiko   Shibata, Takehiko  

    Hypersuppressiveness, as observed in Saccharomyces cerevisiae, is an extremely biased inheritance of a small mitochondrial DNA (mtDNA) fragment that contains a replication origin (HS [rho(-)] mtDNA). Our previous studies showed that concatemers (linear head-to-tail multimers) are obligatory intermediates for mtDNA partitioning and are primarily formed by rolling-circle replication mediated by Mhr1, a protein required for homologous mtDNA recombination. In this study, we found that Mhr1 is required for the hypersuppressiveness of HS [ori5] [rho(-)] mtDNA harboring ori5, one of the replication origins of normal ([rho(+)]) mtDNA. In addition, we detected an Ntg1-stimulated double-strand break at the ori5 locus. Purified Ntg1, a base excision repair enzyme, introduced a double-stranded break by itself into HS [ori5] [rho(-)] mtDNA at ori5 isolated from yeast cells. Both hypersuppressiveness and concatemer formation of HS [ori5] [rho(-)] mtDNA are simultaneously suppressed by the ntg1 null mutation. These results support a model in which, like homologous recombination, rolling-circle HS [ori5] [rho(-)] mtDNA replication is initiated by double-stranded breakage in ori5, followed by Mhr1-mediated homologous pairing of the processed nascent DNA ends with circular mtDNA. The hypersuppressiveness of HS [ori5] [rho(-)] mtDNA depends on a replication advantage furnished by the higher density of ori5 sequences and on a segregation advantage furnished by the higher genome copy number on transmitted concatemers.
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  • Quantifying Impacts of Mean Annual Lake Bottom Temperature on Talik Development and Permafrost Degradation below Expanding Thermokarst Lakes on the Qinghai–Tibet Plateau

    Ling, Feng   Pan, Feifei  

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  • Extracranial-intracranial bypass surgery for occlusive atherosclerotic disease of the anterior cerebral circulation: protocol for a systematic review and meta-analysis

    Bai, Xuesong   Feng, Yao   Yang, Kun   Wang, Tao   Luo, Jichang   Wang, Xue   Ling, Feng   Ma, Yan   Jiao, Liqun  

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  • The association between ambient particulate matters, nitrogen dioxide, and childhood scarlet fever in Hangzhou, Eastern China, 2014–2018

    Cheng, Wei   Li, Huanhuan   Zhang, Xueying   Sun, Wanwan   Chong, Ka Chun   Lau, Steven Yuk-Fai   Yu, Zhao   Liu, Shelan   Ling, Feng   Pan, Jinren   Chen, Enfu  

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  • Imaging of interventional neuroradiology, edited by Feng Ling and Tielin Li., ISBN 7-117-02987-0., Rating: ★★★★, Recommended audience: endovascular neurosurgeons, radiologists, and residents; neurologists, neurosurgeons.

    Ian Ross  

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  • Urban Land Use Mapping by Combining Remote Sensing Imagery and Mobile Phone Positioning Data

    Jia, Yuanxin   Ge, Yong   Ling, Feng   Guo, Xian   Wang, Jianghao   Wang, Le   Chen, Yuehong   Li, Xiaodong  

    Land use is of great importance for urban planning, environmental monitoring, and transportation management. Several methods have been proposed to obtain land use maps of urban areas, and these can be classified into two categories: remote sensing methods and social sensing methods. However, remote sensing and social sensing approaches have specific disadvantages regarding the description of social and physical features, respectively. Therefore, an appropriate fusion strategy is vital for large-area land use mapping. To address this issue, we propose an efficient land use mapping method that combines remote sensing imagery (RSI) and mobile phone positioning data (MPPD) for large areas. We implemented this method in two steps. First, a support vector machine was adopted to classify the RSI and MPPD. Then, the two classification results were fused using a decision fusion strategy to generate the land use map. The proposed method was applied to a case study of the central area of Beijing. The experimental results show that the proposed method improved classification accuracy compared with that achieved using MPPD alone, validating the efficacy of this new approach for identifying land use. Based on the land use map and MPPD data, activity density in key zones during daytime and nighttime was analyzed to illustrate the volume and variation of people working and living across different regions.
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  • Hybrid Recanalization for Symptomatic Long-Segmental Occlusion Post Vertebral Artery Stenting

    Yang, Bin   Ma, Yan   Lu, Xia   Gao, Peng   Jiao, Liqun   Ling, Feng  

    BACKGROUND: A hybrid operation combining endovascular and open surgery procedures is supposed to achieve recanalization for post-stenting longsegmental occlusion of the vertebral artery (VA) ostium simultaneously. CASE DESCRIPTION: One patient with post-stenting long-segmental occlusion in VA ostium was reported. His symptoms could not be relieved by medical therapy. Recanalization combining endovascular and open surgery procedures simultaneously was performed. The hybrid recanalization was successful, and the patient demonstrated no symptoms attacked during the follow-up. CONCLUSIONS: Hybrid operation is a potential and feasible method to recanalize the long-segmental occlusion in the VA ostium post-stenting treatment.
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  • Evaluation of Safety and Efficacy of Qinming8631 DR Implantable Cardiac Pacemaker in Chinese Patients:A Prospective,Multicenter,Randomized Controlled Trial of the First Domestically Developed Pacemaker of China

    Xiang, Mei-Xiang   Wang, Dong-Qi   Xu, Jing   Zhang, Zheng   Hu, Jian-Xin   Wang, Dong-Mei   Gu, Xiang   Liu, He-Ping   Guo, Tao   Yang, Xiang-Jun   Ling, Feng   Lin, Jia-Feng   Cai, Shang-Lang   Zhu, Guo-Bin  

    Background: High cost of imported pacemakers is a main obstacle for Chinese patients suffering from bradyarrhythmia, and a domestically developed pacemaker will help lower the burden. This study aimed to evaluate the safety and efficacy of Qinming8631 DR (Qinming Medical, Baoji, China), the first domestically developed dual-chamber pacemaker of China, compared with a commercially available pacemaker Talos DR (Biotronik, Berlin, Germany) in Chinese patients.Methods: A prospective randomized trial was conducted at 14 centers in China. Participants were randomized into trial (Qinming8631 DR) and control (Talos DR) groups. Parameters of the pacing systems were collected immediately after device implantation and during follow-ups. The effective pacing rate at 6-month follow-up was recorded as the primary end point. Electrical properties, magnet response, single-and double-pole polarity conversion, rate response function, and adverse events of the pacing system were analyzed. The Cochran-Mantel-Haenszel Chi-square test, paired t-test, and Wilcoxon signed-rank test were used for measuring primary qualitative outcomes and comparing normally and abnormally distributed measurement data.Results: A total of 225 patients with a diagnosis ofbradyarrhythmia and eligible for this study were randomly enrolled into the trial (n =3D 113) and control (n =3D 112) groups. They underwent successful pacemaker implantation with acceptable postoperative pacing threshold and sensitivity. Effective pacing rates of trial and control groups were comparable both in the full analysis set and the per protocol set (81.4% vs. 79.5%, P =3D 0.712 and 95.4% vs. 89.5%, P=3D0.143, respectively). In both data sets, noninferiority of the trial group was above the predefined noninferiority limit(-9.5%).Conclusions: This study established the noninferiority of Qinming8631 DR to Talos DR. The safety and efficacy of Qinming8631 DR pacemaker were comparable to those of Talos DR in treating patients with cardiac bradyarrhythmia.
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  • Mild hypothermia diminishes oxidative DNA damage and pro-death signaling events after cerebral ischemia: a mechanism for neuroprotection

    Ji, Xunming   Luo, Yumin   Ling, Feng   Stetler, R. Anne   Lan, Jing   Cao, Guodong   Chen, Jun  

    Mild hypothermia, applied either during or soon after cerebral ischemia, has been shown to confer robust neuroprotection against brain injury in experimental stroke and in patients recovering from cardiac arrest. However, the mechanism underlying hypothermic neuroprotection is not completely understood. In this study, the effect of mild hypothermia on the induction of oxidative DNA damage, an early harmful event during post-ischemic reperfusion that triggers both necrotic and apoptotic cell death in the brain, was studied using the rat model of middle cerebral artery occlusion (MCAO) and reperfusion. Rats were subjected to 2-hr MCAO and reperfusion of various durations up to 3 days. Selective brain hypothermia (33 degrees C) was induced at the onset of ischemia and terminated at the beginning of reperfusion, and this significantly decreased infarct volume 72 hr later. Correlated with this protective effect, intraischemic mild hypothermia markedly attenuated the nuclear accumulations of several oxidative DNA lesions, including 8-oxodG, AP sites, and DNA single-strand breaks, after 2-hr MCAO. Consequently, harmful DNA damage-dependent signaling events, including NAD depletion, p53 activation, and mitochondrial translocation of PUMA and NOXA, were reduced during post-ischemic reperfusion in hypothermia-treated brains. These results suggest that the attenuation of oxidative DNA damage and DNA damage-triggered pro-death signaling events may be an important mechanism underlying the neuroprotective effect of mild hypothermia against ischemic brain injury. reperfusion, and this significantly decreased infarct volume 72 hr later. Correlated with this protective effect, intraischemic mild hypothermia markedly attenuated the nuclear accumulations of several oxidative DNA lesions, including 8-oxodG, AP sites, and DNA single-strand breaks, after 2-hr MCAO. Consequently, harmful DNA damage-dependent signaling events, including NAD depletion, p53 activation, and mitochondrial translocation of PUMA and NOXA, were reduced during post-ischemic reperfusion in hypothermia-treated brains. These results suggest that the attenuation of oxidative DNA damage and DNA damage-triggered pro-death signaling events may be an important mechanism underlying the neuroprotective effect of mild hypothermia against ischemic brain injury.
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  • Experimental research on air staged cyclone gasification of rice husk

    Sun, Shaozeng   Zhao, Yijun   Ling, Feng   Su, Fengming  

    A novel air cyclone gasifier of rice husk has been used to obtain experimental data for air staged gasification. Three positions and five ratios of secondary air were selected to study effect of the secondary air on the temperature profile in the gasifier and quality of syngas. Temperature profile and the syngas component are found to be strongly influenced by the injection position and ratio of the secondary air. Generally, gas temperature in all conditions increased at the early stage of reaction, and then decreased in the reduction zone where reactions were endothermic. The peak temperature in the gasifier changed with the injection positions and ratios of the secondary air, which could be as high as 1056 degrees C. The concentration Of CO(2), CO, H(2) and CH(4) increased with the secondary air while the O(2) concentration remained constant. The syngas component exhibited different laws when the secondary air ratio was changed. It was also shown that the optimum condition was that the secondary air was injected in the oxidization zone at a secondary air ratio of about 31%. Under that condition, the fuel gas production was 1.30 Nm(3)/kg, the low heating value of the syngas was 6.7 MJ/Nm(3), the carbon conversion rate was 92.2% and the cold gas efficiency of the gasifier was 63.2%. The tar content of the syngas was also studied in this paper. It decreased from 4.4 g/m(3) for gasification without the secondary air to 1.6 g/m(3) for gasification with the secondary air injected in the oxidization zone. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.
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  • A case of fourth atlanto-axial facet joint: anatomical description

    Wang, Xing-Wen   Jian, Feng-Zeng   Ling, Feng  

    Purpose To report a rare fourth atlanto-axial joint. Methods A cadaveric specimen of a young male adult from occiput to C4 was dissected for anatomical study of craniocervical region. A true fourth atlanto-axial joint was confirmed. Its morphological characteristics were described. Results The fourth atlantoaxial joint is rarely seen. The possible embryogenesis is discussed. This case raises an anatomical possibility of a new variant in this region. Conclusions A unique case with an anatomically proven fourth atlantoaxial joint is reported. This anomaly can lead to misdiagnosis. CT scan coupled with MRI can facilitate accurate diagnosis.
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  • Sub-pixel mapping of remotely sensed imagery with hybrid intra- and inter-pixel dependence

    Ling, Feng   Li, Xiaodong   Du, Yun   Xiao, Fei  

    Sub-pixel mapping of remotely sensed imagery is often performed by assuming that land cover is spatially dependent both within and between image pixels. Intra- and inter-pixel dependencies are two widely used approaches to represent different land-cover spatial dependencies at present. However, merely using intra- or inter-pixel dependence alone often fails to fully describe land-cover spatial dependence, making current sub-pixel mapping models defective. A more reasonable object for sub-pixel mapping is maximizing both intra- and inter-pixel dependencies simultaneously instead of using only one of them. In this article, the differences between intra- and inter-pixel dependencies are discussed theoretically, and a novel sub-pixel mapping model aiming to maximize hybrid intra- and inter-pixel dependence is proposed. In the proposed model, spatial dependence is formulated as a weighted sum of intra-pixel dependence and inter-pixel dependence to satisfy both intra- and inter-pixel dependencies. By application to artificial and synthetic images, the proposed model was evaluated both visually and quantitatively by comparing with three representative sub-pixel mapping algorithms: the pixel swapping algorithm, the sub-pixel/pixel attraction algorithm, and the pixel swapping initialized with sub-pixel/pixel attraction algorithm. The results showed increased accuracy of the proposed algorithm when compared with these traditional sub-pixel mapping algorithms.
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  • The Problematics of Self in Modern Chinese Literature: Hu Feng and Lu Ling

    Wang, Ban; Denton, Kirk A.  

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