4,471 research outputs found

    Graphical history list on world wide web visualisation: A usability paradigm

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    The World Wide Web (WWW) is a fast emerging technology which enables users to view the information via a web browser such as Internet Explorer and Netscape Navigator.Studies have revealed that users often get ‘lost’ as they navigate deeper and deeper.Information visualisation is adopted by many researchers to construct the graphical representation of history list as text-based imposes a burden on users. Although information visualisation is a useful tool, questions arise on its usability and human short term memory.A prototype of a graphical history list is developed while taking the usability and human short term memory into considerations.The research results have significantly indicated a positive and promising outcome on a usable graphical history list on WWW visualisation

    Eigenvalue variance bounds for Wigner and covariance random matrices

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    This work is concerned with finite range bounds on the variance of individual eigenvalues of Wigner random matrices, in the bulk and at the edge of the spectrum, as well as for some intermediate eigenvalues. Relying on the GUE example, which needs to be investigated first, the main bounds are extended to families of Hermitian Wigner matrices by means of the Tao and Vu Four Moment Theorem and recent localization results by Erd\"os, Yau and Yin. The case of real Wigner matrices is obtained from interlacing formulas. As an application, bounds on the expected 2-Wasserstein distance between the empirical spectral measure and the semicircle law are derived. Similar results are available for random covariance matrices

    Background Parenchymal Enhancement of the Contralateral Normal Breast: Association with Tumor Response in Breast Cancer Patients Receiving Neoadjuvant Chemotherapy

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    AbstractPURPOSE: This study investigated the association between background parenchymal enhancement (BPE) and pathologic response to neoadjuvant chemotherapy (NAC). METHODS: A total of 46 patients diagnosed with invasive breast cancer were analyzed. Each patient had three magnetic resonance imaging (MRI) studies, one pre-treatment and two follow-up (F/U) MRI studies. BPE was measured as the averaged enhancement of the whole fibroglandular tissues. The pre-treatment BPE and the changes in the F/U MRI were compared between patients achieving pathologic complete response (pCR) versus those not. Subgroup analyses based on age, estrogen receptor (ER), and human epidermal growth factor receptor 2 (HER2) status of their cancers were also performed. RESULTS: The pre-treatment BPE was higher in the pCR group than that in the non-pCR group. Compared to baseline, BPE at F/U-1 was significantly decreased in the pCR group but not in the non-pCR group. In subgroup analysis based on age, these results were seen only in the younger group (<55 years old), not in the older group (≥55 years old). Older patients had a significantly lower pre-treatment BPE than younger patients. In analysis based on molecular biomarkers, a significantly decreased BPE at F/U-1 was only found in the ER-negative pCR group but not in the non-pCR, nor in the ER-positive groups. CONCLUSIONS: A higher pre-treatment BPE showing a significant decrease early after starting NAC was related to pCR in pre/peri-menopausal patients

    Characterization of Pure Ductal Carcinoma In Situ on Dynamic Contrast-Enhanced MR Imaging: Do Nonhigh Grade and High Grade Show Different Imaging Features?

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    To characterize imaging features of pure DCIS on dynamic contrast-enhanced MR imaging (DCE-MRI), 31 consecutive patients (37-81 years old, mean 56), including 2 Grade I, 16 Grade II, and 13 Grade III, were studied. MR images were reviewed retrospectively and the morphological appearances and kinetic features of breast lesions were categorized according to the ACR BI-RADS breast MRI lexicon. DCE-MRI was a sensitive imaging modality in detecting pure DCIS. MR imaging showed enhancing lesions in 29/31 (94%) cases. Pure DCIS appeared as mass type or non-mass lesions on MRI with nearly equal frequency. The 29 MR detected lesions include 15 mass lesions (52%), and 14 lesions showing non-mass-like lesions (48%). For the mass lesions, the most frequent presentations were irregular shape (50%), irregular margin (50%) and heterogeneous enhancement (67%). For the non-mass-like lesions, the clumped internal enhancement pattern was the dominate feature, seen in 9/14 cases (64%). Regarding enhancement kinetic curve, 21/29 (78%) lesions showed suspicious malignant type kinetics. No significant difference was found in morphology (P > .05), tumor size (P = 0.21), and kinetic characteristics (P = .38) between non-high grade (I+II) and high-grade (III) pure DCIS

    Chronic Lung Function Decline in Cotton Textile Workers: Roles of Historical and Recent Exposures to Endotoxin

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    BackgroundLong-term occupational exposure to cotton dust that contains endotoxin is associated with chronic respiratory symptoms and excessive decline in forced expiratory volume in 1 sec (FEV1), but the mechanisms of endotoxin-related chronic airflow obstruction remain unclear.ObjectiveIn the current study, we examined temporal aspects of the exposure-response relationship between airborne endotoxin exposure, longitudinal change in FEV1, and respiratory symptoms in a cohort of Chinese cotton textile workers.MethodsThis prospective cohort study followed 447 cotton textile workers from 1981 to 2006. at approximately 5-year intervals. We used a generalized estimating equations approach to model FEV1 level and respiratory symptoms as a function of past exposure (cumulative exposure up to the start of the most recent 5-year survey interval) and cumulative exposure (within the most recent interval) to endotoxins, after adjusting for other covariates. Models were stratified by active versus retired work status and by years employed before the baseline survey (&lt; 5 and &gt; or = 5 years).Results and conclusionsPast exposure to endotoxin was associated with reduced FEV1 level among retired cotton workers. Among all cotton workers, past exposure was more strongly associated with reduced FEV1 for those hired &lt; 5 years before baseline than for those who were hired &gt; or = 5 years after baseline. Recent endotoxin exposure was significantly associated with byssinosis, chronic bronchitis, and chronic cough

    Interventional Spine and Pain Procedure Credentialing: Guidelines from the American Society of Pain & Neuroscience

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    Background: The discipline of interventional pain management has changed significantly over the past decade with an expected greater evolution in the next decade. Not only have the number of procedures increased, some of the procedures that were created for spine surgeons are becoming more facile in the hands of the interventional pain physician. Such change has outpaced academic institutions, societies, and boards. When a pain physician is in the credentialing process for novel procedure privileges, it can leave the healthcare system in a challenging situation with little to base their decision upon. Methods: This paper was developed by a consensus working group from the American Society of Pain and Neuroscience from various disciplines. The goal was to develop processes and resources to aid in the credentialing process. Results: These guidelines from the American Society of Pain and Neuroscience provide background information to help facilities create a process to appropriately credential physicians on novel procedures. They are not intended to serve as a standard or legal precedent. Conclusion: This paper serves as a guide for facilities to credential physicians on novel procedures

    1,7-Dimethyl­penta­cyclo­[5.4.0.02,6.03,10.05,9]undecane-8,11-dione

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    The structure of the title compound, C13H14O2, a penta­cyclo­undecane cage derivative, exhibits unusual Csp 3—Csp 3 single-bond lengths ranging from 1.505 (3) to 1.607 (2) Å and strained bond angles as small as 88.7 (1)° and as large as 121.0 (2)°. In this meso compound, an inter­nal non-crystallographic mirror plane exists, bis­ecting the mol­ecule. In the crystal, weak C—H⋯O hydrogen bonds link the mol­ecules into an infinite spiral about a twofold screw axis along the [100] direction

    Mucosal injury following short term tracheal intubation: a novel animal model and composite injury score

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    Objectives: Postintubation laryngotracheal injury is common. Assessment of histopathological changes currently requires animal models. We set about developing a viable, resource effective animal model to study these effects and to develop a detailed tissue injury score. Methods: Six pigs were anaesthetised using a standard regimen. We intubated the tracheas using a standard endotracheal tube modified to include optical sensors. Animals were anaesthetised for a duration of two to four hours, and their lungs were ventilated using a normoxic gas mixture. Following euthanasia, the tracheas were removed and underwent histological assessment by two independent veterinary pathologists. The histological lesions, including controls, were described and quantified, and two pathologists classified tissues according to a novel injury score. Results: Mean duration of tracheal intubation was 191 minutes (SD±41.6). In all except one animal, cuff pressures were maintained in the range of 25 – 45 cmH20. Histopathological findings in all study animals showed more extensive changes than previously described with short-term intubation. Changes were seen in all mucosal layers consistent with acute, suppurative and ulcerative tracheitis. The range of scores of the developed composite scoring system among the animals was wider than in earlier descriptions. There was a high percentage of agreement between both pathologists. Conclusions: We have described a novel tissue injury score to assess pathological changes following short term intubation in a viable animal model. The scoring system distinguished between the test animals as well as controls and may be appropriate for continuing study of intubation injury
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