3,404 research outputs found

    Impurity resonance states in electron-doped high T_c superconductors

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    Two scenarios, i.e., the anisotropic s-wave pairing (the s-wave scenario) and the d-wave pairing coexisting with antiferromagnetism (the coexisting scenario) have been introduced to understand some of seemingly s-wave like behaviors in electron doped cuprates. We considered the electronic structure in the presence of a nonmagnetic impurity in the coexistence scenario. We found that even if the AF order opens a full gap in quasi-particle excitation spectra, the mid-gap resonant peaks in local density of states (LDoS) around an impurity can still be observed in the presence of a d-wave pairing gap. The features of the impurity states in the coexisting phase are markedly different from the pure AF or pure d-wave pairing phases, showing the unique role of the coexisting AF and d-wave pairing orders. On the other hand, it is known that in the pure s-wave case no mid-gap states can be induced by a nonmagnetic impurity. Therefore we proposed that the response to a nonmagnetic impurity can be used to differentiate the two scenarios.Comment: 5 pages, two-column revtex4, 5 figures, author list correcte

    Prediction of large esophageal varices in cirrhotic patients using classification and regression tree analysis

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    OBJECTIVES: Recent guidelines recommend that all cirrhotic patients should undergo endoscopic screening for esophageal varices. That identifying cirrhotic patients with esophageal varices by noninvasive predictors would allow for the restriction of the performance of endoscopy to patients with a high risk of having varices. This study aimed to develop a decision model based on classification and regression tree analysis for the prediction of large esophageal varices in cirrhotic patients. METHODS: 309 cirrhotic patients (training sample, 187 patients; test sample 122 patients) were included. Within the training sample, the classification and regression tree analysis was used to identify predictors and prediction model of large esophageal varices. The prediction model was then further evaluated in the test sample and different Child-Pugh classes. RESULTS: The prevalence of large esophageal varices in cirrhotic patients was 50.8%. A tree model that was consisted of spleen width, portal vein diameter and prothrombin time was developed by classification and regression tree analysis achieved a diagnostic accuracy of 84% for prediction of large esophageal varices. When reconstructed into two groups, the rate of varices was 83.2% for high-risk group and 15.2% for low-risk group. Accuracy of the tree model was maintained in the test sample and different Child-Pugh classes. CONCLUSIONS: A decision tree model that consists of spleen width, portal vein diameter and prothrombin time may be useful for prediction of large esophageal varices in cirrhotic patient

    Low major histocompatibility complex class II DQA diversity in the Giant Panda (Ailuropoda melanoleuca)

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    © 2007 Zhu et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

    Laparoscopic Removal of a Broken Sewing Needle in a Patient with Irritative Bladder Symptoms

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    A foreign body near the bladder is rare. Although foreign bodies in the bladder can be easily found and removed by endoscopic transurethral removal, extravesical foreign bodies may require the use of an open or laparoscopic procedure. Here, we report a case of a patient complaining of frequency and urgency in whom an extravesical sewing needle was successfully removed by a laparoscopic approach. A 4.5 cm rusty sewing needle was found between the bladder and the left external iliac vessels and was removed through a 5 mm trocar port by use of endo forceps with no complications

    Neuro-inflammation induced by lipopolysaccharide causes cognitive impairment through enhancement of beta-amyloid generation

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    <p>Abstract</p> <p>Background</p> <p>Alzheimer's disease (AD) is characterized by extensive loss of neurons in the brain of AD patients. Intracellular accumulation of beta-amyloid peptide (Aβ) has also shown to occur in AD. Neuro-inflammation has been known to play a role in the pathogenesis of AD.</p> <p>Methods</p> <p>In this study, we investigated neuro-inflammation and amyloidogenesis and memory impairment following the systemic inflammation generated by lipopolysaccharide (LPS) using immunohistochemistry, ELISA, behavioral tests and Western blotting.</p> <p>Results</p> <p>Intraperitoneal injection of LPS, (250 μg/kg) induced memory impairment determined by passive avoidance and water maze tests in mice. Repeated injection of LPS (250 μg/kg, 3 or 7 times) resulted in an accumulation of Aβ<sub>1–42 </sub>in the hippocampus and cerebralcortex of mice brains through increased β- and γ-secretase activities accompanied with the increased expression of amyloid precursor protein (APP), 99-residue carboxy-terminal fragment of APP (C99) and generation of Aβ<sub>1–42 </sub>as well as activation of astrocytes <it>in vivo</it>. 3 weeks of pretreatment of sulindac sulfide (3.75 and 7.5 mg/kg, orally), an anti-inflammatory agent, suppressed the LPS-induced amyloidogenesis, memory dysfunction as well as neuronal cell death <it>in vivo</it>. Sulindac sulfide (12.5–50 μM) also suppressed LPS (1 μg/ml)-induced amyloidogenesis in cultured neurons and astrocytes <it>in vitro</it>.</p> <p>Conclusion</p> <p>This study suggests that neuro-inflammatory reaction could contribute to AD pathology, and anti-inflammatory agent could be useful for the prevention of AD.</p
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