634 research outputs found

    A note on the stability of Toeplitz matrix inversion formulas

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    AbstractIn this paper, we consider the stability of the algorithms emerging from Toeplitz matrix inversion formulas. We show that if the Toeplitz matrix is nonsingular and well-conditioned, then they are numerically forward stable

    Computational Procedure of Performance Assessment of Lifetime Index of Products for the Weibull Distribution with the Progressive First-Failure-Censored Sampling Plan

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    Process capability analysis has been widely applied in the field of quality control to monitor the performance of industrial processes. In practice, lifetime performance index CL is a popular means to assess the performance and potential of their processes, where L is the lower specification limit. This study will apply the large-sample theory to construct a maximum likelihood estimator (MLE) of CL with the progressive first-failure-censored sampling plan under the Weibull distribution. The MLE of CL is then utilized to develop a new hypothesis testing procedure in the condition of known L

    MeInfoText 2.0: gene methylation and cancer relation extraction from biomedical literature

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    <p>Abstract</p> <p>Background</p> <p>DNA methylation is regarded as a potential biomarker in the diagnosis and treatment of cancer. The relations between aberrant gene methylation and cancer development have been identified by a number of recent scientific studies. In a previous work, we used co-occurrences to mine those associations and compiled the MeInfoText 1.0 database. To reduce the amount of manual curation and improve the accuracy of relation extraction, we have now developed MeInfoText 2.0, which uses a machine learning-based approach to extract gene methylation-cancer relations.</p> <p>Description</p> <p>Two maximum entropy models are trained to predict if aberrant gene methylation is related to any type of cancer mentioned in the literature. After evaluation based on 10-fold cross-validation, the average precision/recall rates of the two models are 94.7/90.1 and 91.8/90% respectively. MeInfoText 2.0 provides the gene methylation profiles of different types of human cancer. The extracted relations with maximum probability, evidence sentences, and specific gene information are also retrievable. The database is available at <url>http://bws.iis.sinica.edu.tw:8081/MeInfoText2/</url>.</p> <p>Conclusion</p> <p>The previous version, MeInfoText, was developed by using association rules, whereas MeInfoText 2.0 is based on a new framework that combines machine learning, dictionary lookup and pattern matching for epigenetics information extraction. The results of experiments show that MeInfoText 2.0 outperforms existing tools in many respects. To the best of our knowledge, this is the first study that uses a hybrid approach to extract gene methylation-cancer relations. It is also the first attempt to develop a gene methylation and cancer relation corpus.</p

    Case Report: Hexachloroethane Smoke Inhalation: A Rare Cause of Severe Hepatic Injuries

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    CONTEXT: We report on two patients, a 23-year-old man and a 24-year-old man, who had chemical pneumonitis and respiratory distress after inhaling hexachloroethane/zinc oxide (HC/ZnO) smoke during military training. CASE PRESENTATION: The patients had been healthy previously and denied any history of alcohol or drug abuse. Hematologic tests revealed leukocytosis with neutrophils predominant. The respiratory conditions of both patients improved after steroid therapy and oxygen support, but deterioration of liver function was found. The laboratory results showed that alanine aminotransferase (ALT) and γ-glutamyl transpeptidase levels were elevated about 1.5-fold the normal limits and that aspartate aminotransferase (AST) levels were marginally elevated. The elevation of liver aminotransferase started from day 1 and day 2 and peaked from day 18 to day 22. ALT/AST levels then returned to normal in 6 weeks. Common viral hepatitis was ruled out after serologic tests. Abdominal sonography and physical examination failed to show any specific findings. DISCUSSION: The hepatotoxic effect was attributed to inhalation of high-concentration HC/ZnO smoke in an enclosed area, where several hepatotoxicants, including ZnCl(2), HC, and chlorinated vapors, could have been generated and mixed in the smoke. RELEVANCE TO CLINICAL PRACTICE: These case reports elaborate the hepatic effects that may occur in addition to pulmonary effects of HC/ZnO smoke

    Characteristics of Boron Decorated TiO 2 Nanoparticles for Dye-Sensitized Solar Cell Photoanode

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    Different boron weight percents on mixed-phase (anatase and rutile) TiO 2 nanoparticles were synthesized to investigate structure morphology, defect states, luminescence properties, and energy conversion. The measured results indicate that boron doping of TiO 2 both increases the crystallite size and rutile-phase percent in an anatase matrix. Decreasing the band gap by boron doping can extend the absorption to the visible region, while undoped TiO 2 exhibits high UV absorption. Oxygen vacancy defects generated by boron ions reduce Ti +4 and affect electron transport in dye-sensitized solar cells. Excess electrons originating from the oxygen vacancies of doped TiO 2 downward shift in the conduction band edge and prompt the transfer of photoelectrons from the conduction band of the rutile phase to the lower energy anatase trapping sites; they then separate charges to enhance the photocurrent and sc . Although the resistance of the electron recombination ( ) between doped TiO 2 photoanode and the electrolyte for the doped TiO 2 sample is lower, a longer electron lifetime ( ) of 19.7 ms with a higher electron density ( ) of 2.1 × 10 18 cm −3 contributes to high solar conversion efficiency

    Relaxed Viscosity Approximation Methods with Regularization for Constrained Minimization Problems

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    We introduce a new relaxed viscosity approximation method with regularization and prove the strong convergence of the method to a common fixed point of finitely many nonexpansive mappings and a strict pseudocontraction that also solves a convex minimization problem and a suitable equilibrium problem

    Activation of Endothelial Cells by Antiphospholipid Antibodies—A Possible Mechanism Triggering Thrombosis in Patients with Antiphospholipid Syndrome

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    Antiphospholipid syndrome (APS) is an antibody-mediated hypercoagulable state characterized by recurrent venous and arterial thromboembolic events. The presence of serum antibodies are collectively termed as antiphospholipid antibodies (aPL) and is the hallmark of the disease. Interest in the pathogenesis has mostly been focused on the blood coagulation factor. However, endothelial cells might play an important role. When stimulated, cell membrane would flip to expose negatively charged phospholipids and activation markers such as adhesive molecules may appear. We consider that these changes may play an important role in the initiation of the thrombotic process when endothelial cells encounter aPL. In this study, we incubated human umbilical vein endothelial cells (HUVECs) with IgG isolated from patients with APS and found that the HUVECs were activated by the expression of negatively charged phospholipids, as shown by high annexin V binding and negative propidium iodide staining and by an increase in the level of intracellular cell adhesion molecule-1 on the cell surface. The above findings indicate that endothelial cells can be activated on exposure to aPL and trigger the thrombotic event

    UMARS: Un-MAppable Reads Solution

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    [[abstract]]Background: Un-MAppable Reads Solution (UMARS) is a user-friendly web service focusing on retrieving valuable information from sequence reads that cannot be mapped back to reference genomes. Recently, next-generation sequencing (NGS) technology has emerged as a powerful tool for generating high-throughput sequencing data and has been applied to many kinds of biological research. In a typical analysis, adaptor-trimmed NGS reads were first mapped back to reference sequences, including genomes or transcripts. However, a fraction of NGS reads failed to be mapped back to the reference sequences. Such un-mappable reads are usually imputed to sequencing errors and discarded without further consideration.Methods: We are investigating possible biological relevance and possible sources of un-mappable reads. Therefore, we developed UMARS to scan for virus genomic fragments or exon-exon junctions of novel alternative splicing isoforms from un-mappable reads. For mapping un-mappable reads, we first collected viral genomes and sequences of exon-exon junctions. Then, we constructed UMARS pipeline as an automatic alignment interface.Results: By demonstrating the results of two UMARS alignment cases, we show the applicability of UMARS. We first showed that the expected EBV genomic fragments can be detected by UMARS. Second, we also detected exon-exon junctions from un-mappable reads. Further experimental validation also ensured the authenticity of the UMARS pipeline. The UMARS service is freely available to the academic community and can be accessed via http://musk.ibms.sinica.edu.tw/UMARS/.Conclusions: In this study, we have shown that some un-mappable reads are not caused by sequencing errors. They can originate from viral infection or transcript splicing. Our UMARS pipeline provides another way to examine and recycle the un-mappable reads that are commonly discarded as garbage

    A 64-week, multicenter, open-label study of aripiprazole effectiveness in the management of patients with schizophrenia or schizoaffective disorder in a general psychiatric outpatient setting

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    <p>Abstract</p> <p>Objective</p> <p>To evaluate the overall long-term effectiveness of aripiprazole in patients with schizophrenia in a general psychiatric practice setting in Taiwan.</p> <p>Methods</p> <p>This was a prospective, open-label, multicenter, post-market surveillance study in Taiwanese patients with a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) diagnosis of schizophrenia or schizoaffective disorder requiring a switch in antipsychotic medication because current medication was not well tolerated and/or clinical symptoms were not well controlled. Eligible patients were titrated to aripiprazole (5-30 mg/day) over a 12-week switching phase, during which their previous medication was discontinued. Patients could then enter a 52-week, long-term treatment phase. Aripiprazole was flexibly dosed (5-30 mg/day) at the discretion of the treating physicians. Efficacy was assessed using the Clinical Global Impression scale Improvement (CGI-I) score, the Clinical Global Impression scale Severity (CGI-S) score, The Brief Psychiatry Rating Scale (BPRS), and the Quality of Life (QOL) scale, as well as Preference of Medicine (POM) ratings by patients and caregivers. Safety and tolerability were also assessed.</p> <p>Results</p> <p>A total of 245 patients were enrolled and switched from their prior antipsychotic medications, and 153 patients entered the 52-week extension phase. In all, 79 patients (32.2%) completed the study. At week 64, the mean CGI-I score was 3.10 and 64.6% of patients who showed response. Compared to baseline, scores of CGI-S, QOL, and BPRS after 64 weeks of treatment also showed significant improvements. At week 12, 65.4% of subjects and 58.9% of caregivers rated aripiprazole as better than the prestudy medication on the POM. The most frequently reported adverse events (AEs) were headache, auditory hallucinations and insomnia. A total of 13 patients (5.3%) discontinued treatment due to AEs. No statistically significant changes were noted with respect to fasting plasma glucose, lipid profile, body weight, and body mass index after long-term treatment with aripiprazole.</p> <p>Conclusions</p> <p>Although the discontinuation rate was high, aripiprazole was found to be effective, safe and well tolerated in the long-term treatment of Taiwanese patients with schizophrenia who continued to receive treatment for 64 weeks.</p
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