Kan Xu

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In this paper, we use query-level regression as the loss function. The regression loss function has been used in pointwise methods, however pointwise methods ignore the query boundaries and treat the data equally across queries, and thus the effectiveness is limited. We show that regression is an effective loss function for learning to rank when used in(More)
While the citation context of a reference may provide detailed and direct information about the nature of a citation, few studies have specifically addressed the role of this information in retrieving relevant documents from the literature primarily due to the lack of full text databases. In this paper, we design a retrieval system based on full texts in(More)
Lateral ventricular meningiomas presenting with primary intraventricular hemorrhage are extremely uncommon. We report here a case of primary intraventricular hemorrhage attributable to a lateral ventricular meningioma. This case concerns a 46-year-old female patient who presented with sudden onset of headache. Computed tomography (CT), computed tomography(More)
The treatment of aneurysms associated with moyamoya disease (MMD) is difficult for neurosurgeons, and little is known of strategy options. This report constitutes a comprehensive review of the literature. We summarize the known treatments and their clinical outcomes according to the site of the aneurysm: in major arteries, peripheral arteries, moyamoya(More)
Spinal cord injury (SCI) is a serious neurotrauma that can lead to life-long disability; to date, no suitable therapeutic strategy exists. Axons do not regenerate after SCI in adult mammals and loss of skeletal muscle mass occurs very rapidly after SCI. Promotion of neurite growth through improving the extracellular environment allows only a limited degree(More)
A proper understanding of how complex networks grow is important to get insights into the network structure, make predictions of future growth, and enable simulation of large networks. In this paper, we focus on social networks and try to understand, capture and predict dynamic behaviors on social networks. How social networks evolve, i.e. how individuals(More)
In accordance with the World Cancer Report, cancer has become the leading cause of mortality worldwide, and various therapeutic strategies have been developed at the same time. In the present study, biocompatible magnetic nanoparticles were designed and synthesized as high-performance photothermal agents for near-infrared light mediated cancer therapy in(More)
Vertebrobasilar dolichoectasia (VBD) is a rare disease characterized by significant expansion, elongation, and tortuosity of the vertebrobasilar arteries. Current data regarding VBD are very limited. Here we systematically review VBD incidence, etiology, characteristics, clinical manifestations, treatment strategies, and prognosis. The exact incidence rate(More)
Recovery after spinal cord injury (SCI) is rare in humans and experimental animals. Following SCI in adults, changes in gene expression and the regulation of these genes are associated with the pathological development of the injury. High levels of brain-derived neurotrophic factor (BDNF) in the injury area during the post-injury period contribute to(More)
It is very rare that a foramen magnum arachnoid cyst induces compression of the spinal cord and syringomyelia, and currently there are few treatment experiences available. Here we reported the case of a 43-year-old male patient who admitted to the hospital due to weakness and numbness of all 4 limbs, with difficulty in urination and bowel movement. MRI(More)