790 research outputs found

    A study of the removal of alkyl benzene sulfonate by means of a column packed with sand coated with ferric oxide

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    Iron, precipitated in the form of hydroxides on sand particles (-48 + 65 mesh) and stabilized by drying at 100°C for 10 hours, was utilized to remove alkyl benzene sulfonate (ABS) from aqueous solutions. Solutions containing a maximum of 5 mg/l ABS were passed through a glass column packed with treated sand. The ABS formed a complex with the iron precipitants which adhered to the sand particles. Preliminary work, in which solutions containing 10 mg/l ABS were treated with various concentrations of FeCl2 at the equivalence point (pH about 9.5), verified the fact that ABS could be removed by this type of treatment. The concentration of ABS was reduced from 10 mg/l to a limiting value of 4.5 mg/l by treating 100 ml of the ABS solution with 10 ml of 0.0071 N FeCl2 solution under these conditions. A glass column (1.5 inch inside diameter), filled to a depth of twelve inches with 516 gm sand treated in three runs with 10, 20, and 40 ml respectively of 0.0071 N FeCl2 solution, was used to evaluate the adsorption of ABS. The quantity of ABS adsorbed from solutions of 5 mg/l ABS, flowing through the column at rates of 100 ml/hr, was proportional to the amount of iron precipitated (0.12 gm ABS/gm iron) on the sand. The removal of the ABS is attributed solely to the influence of the precipitated iron since there was no measurable effects with an untreated column. The desorption of ABS with water was quantitative in the case of the sands treated with the quantities of iron less than 1.5 x 10-5 gm/gm sand. Approximately one-third of the ABS remained in the complexed form on the sand surface when 3 x 10-5 gm iron/gm sand was used to treat the sand. The specific resistance (to flow) of the sand increased from 2.87 x 107 ft/lb, for the untreated sand, to 3.75 x 107 ft/lb, for sand treated with the maximum amount of iron. The specific resistance of the treated sand saturated with ABS was slightly greater than the treated sand free of ABS (3.89 x 107 ft/lb maximum). The techniques utilized in this investigation can be used to evaluate other similar situations --Abstract, pages ii-ii

    Effectiveness of influenza vaccination in patients with end-stage renal disease receiving hemodialysis: a population-based study.

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    BackgroundLittle is known on the effectiveness of influenza vaccine in ESRD patients. This study compared the incidence of hospitalization, morbidity, and mortality in end-stage renal disease (ESRD) patients undergoing hemodialysis (HD) between cohorts with and without influenza vaccination.MethodsWe used the insurance claims data from 1998 to 2009 in Taiwan to determine the incidence of these events within one year after influenza vaccination in the vaccine (N = 831) and the non-vaccine (N = 3187) cohorts. The vaccine cohort to the non-vaccine cohort incidence rate ratio and hazard ratio (HR) of morbidities and mortality were measured.ResultsThe age-specific analysis showed that the elderly in the vaccine cohort had lower hospitalization rate (100.8 vs. 133.9 per 100 person-years), contributing to an overall HR of 0.81 (95% confidence interval (CI) 0.72-0.90). The vaccine cohort also had an adjusted HR of 0.85 [95% CI 0.75-0.96] for heart disease. The corresponding incidence of pneumonia and influenza was 22.4 versus 17.2 per 100 person-years, but with an adjusted HR of 0.80 (95% CI 0.64-1.02). The vaccine cohort had lowered risks than the non-vaccine cohort for intensive care unit (ICU) admission (adjusted HR 0.20, 95% CI 0.12-0.33) and mortality (adjusted HR 0.50, 95% CI 0.41-0.60). The time-dependent Cox model revealed an overall adjusted HR for mortality of 0.30 (95% CI 0.26-0.35) after counting vaccination for multi-years.ConclusionsESRD patients with HD receiving the influenza vaccination could have reduced risks of pneumonia/influenza and other morbidities, ICU stay, hospitalization and death, particularly for the elderly

    Larkin-Ovchinnikov-Fulde-Ferrell phase in the superconductor (TMTSF)2ClO4: Theory versus experiment

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    We consider a formation of the Larkin-Ovchinnikov-Fulde-Ferrell (LOFF) phase in a quasi-one-dimensional (Q1D) conductor in a magnetic field, parallel to its conducting chains, where we take into account both the paramagnetic spin-splitting and orbital destructive effects against superconductivity. We show that, due to a relative weakness of the orbital effects in a Q1D case, the LOFF phase appears in (TMTSF)2_2ClO4_4 superconductor for real values of its Q1D band parameters. We compare our theoretical calculations with the recent experimental data by Y. Maeno's group [S. Yonezawa et al., Phys. Rev. Lett. \textbf{100}, 117002 (2008)] and show that there is a good qualitative and quantitative agreement between the theory and experimental data.Comment: 4 pages, 1 figur

    Autologous serum therapy in recalcitrant laser-assisted in situ keratomileusis-induced neurotrophic epitheliopathy

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    AbstractBackground/PurposeTo evaluate the efficacy of autologous serum eye drops for patients with recalcitrant laser-assisted in situ keratomileusis (LASIK)-induced neurotrophic epitheliopathy (LINE) unresponsive to conventional treatment, and to determine the possible predisposing risk factors of these patients.MethodsWe enrolled 10 consecutive patients (20 eyes) undergoing femtosecond-assisted myopic LASIK surgery presenting with recalcitrant LINE for > 1 year. Another 340 patients (713 eyes) receiving femtosecond-assisted myopic LASIK without recalcitrant LINE were set as controls. Possible risk factors associated with recalcitrant LINE were investigated. Twenty percent autologous serum treatment was prescribed to 20 eyes. The efficacy of autologous serum was assessed with ocular surface conditions, tear function, and the change of best-corrected visual acuity.ResultsAge older than 30 years [odds ratio (OR) = 7.74; 95% confidence interval (CI), 1.74–34.50], flap thickness < 110 μm (OR = 3.47; 95% CI, 1.22–9.73), and a flap diameter < 8.5 mm (OR = 5.38; 95% CI, 1.95–14.85) pose higher risks in femtosecond laser-assisted myopic LASIK. All eyes (100%) achieved remission after autologous serum treatment. The visual acuity before treatment was 0.49 ± 0.41 in LogMAR, and the visual acuity after treatment was 0.14 ± 0.22 in LogMAR. Time to achieve remission was 8.26 ± 11.87 weeks. Mean relapse-free survival after discontinuing autologous serum was 47 weeks.ConclusionRisk factors of recalcitrant LINE in femtosecond laser-assisted myopic LASIK were identified as older age, a thinner flap (<110 μm), and a small flap diameter (<8.5 mm). Autologous serum eye drops can effectively improve corneal surface conditions and postoperative visual acuity

    Early utilization of hypertonic peritoneal dialysate and subsequent risks of non-traumatic amputation among peritoneal dialysis patients: a nationwide retrospective longitudinal study

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    BACKGROUND: The hemodialysis (HD) population has a particularly high incidence of amputation, which is likely associated with decreased tissue oxygenation during HD. However, information about the risk factors leading to amputation in peritoneal dialysis (PD) patients is limited. Here, we have investigated the association between the use of hypertonic peritoneal dialysate (HPD) and subsequent amputation in PD patients. METHODS: Based on the data from the Taiwan National Health Insurance research database, this observational cohort study enrolled 203 PD patients who had received HPD early during treatment and had not undergone amputation and 296 PD controls who had not undergone amputation. Subjects were followed through until the end of 2009 and the event rates of new non-traumatic amputation were compared between groups. RESULTS: The incidence of amputation was 3 times higher for the HPD cohort than for the comparison cohort (23.68 vs. 8.01 per 1000 person-years). The hazard ratio (HR) for this group, estimated using a multivariable Cox model, was 2.48 (95% confidence interval [CI] = 1.06–5.79). The HR for patients with both diabetes and early adoption of HPD increased to 44.34 (95% CI = 5.51-357.03), compared to non-HPD non-diabetic PD controls. CONCLUSION: Early utilization of HPD in PD patients is associated with increasing risk of amputation; this risk considerably increases for those with concomitant diabetes

    The Alliance for Cellular Signaling Plasmid Collection: A Flexible Resource for Protein Localization Studies and Signaling Pathway Analysis

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    Cellular responses to inputs that vary both temporally and spatially are determined by complex relationships between the components of cell signaling networks. Analysis of these relationships requires access to a wide range of experimental reagents and techniques, including the ability to express the protein components of the model cells in a variety of contexts. As part of the Alliance for Cellular Signaling, we developed a robust method for cloning large numbers of signaling ORFs into Gateway® entry vectors, and we created a wide range of compatible expression platforms for proteomics applications. To date, we have generated over 3000 plasmids that are available to the scientific community via the American Type Culture Collection. We have established a website at www.signaling-gateway.org/data/plasmid/ that allows users to browse, search, and blast Alliance for Cellular Signaling plasmids. The collection primarily contains murine signaling ORFs with an emphasis on kinases and G protein signaling genes. Here we describe the cloning, databasing, and application of this proteomics resource for large scale subcellular localization screens in mammalian cell lines

    Employee share ownership in a unionised duopoly

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    Profit sharing schemes have been analysed assuming Cournot competition and decentralised wage negotiations, and it has been found that firms share profits in equilibrium. This paper analyses a different remuneration system: employee share ownership. We find that whether firms choose to share ownership or not depends on both the type of competition in the product market and the way in which workers organise to negotiate wages. If wage setting is decentralised, under duopolistic Cournot competition both firms share ownership. If wage setting is centralised, only one firm shares ownership if the degree to which goods are substitutes takes an intermediate value; otherwise, the two firms share ownership. In this case, if the union sets the same wage for all workers neither firm shares ownership. Therefore, centralised wage setting discourages share ownership. Fi- nally, under Bertrand competition neither firm shares ownership regardless of how workers are organised to negotiate wages.info:eu-repo/semantics/publishedVersio

    A Large Population Histology Study Showing the Lack of Association between ALT Elevation and Significant Fibrosis in Chronic Hepatitis B

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    OBJECTIVE: We determined the association between various clinical parameters and significant liver injury in both hepatitis B e antigen (HBeAg)-positive and HBeAg-negative patients. METHODS: From 1994 to 2008, liver biopsy was performed on 319 treatment-naive CHB patients. Histologic assessment was based on the Knodell histologic activity index for necroinflammation and the Ishak fibrosis staging for fibrosis. RESULTS: 211 HBeAg-positive and 108 HBeAg-negative patients were recruited, with a median age of 31 and 46 years respectively. 9 out of 40 (22.5%) HBeAg-positive patients with normal ALT had significant histologic abnormalities (necroinflammation grading >/= 7 or fibrosis score >/= 3). There was a significant difference in fibrosis scores among HBeAg-positive patients with an ALT level within the Prati criteria (30 U/L for men, 19 U/L for women) and patients with a normal ALT but exceeding the Prati criteria (p = 0.024). Age, aspartate aminotransferase and platelet count were independent predictors of significant fibrosis in HBeAg-positive patients with an elevated ALT by multivariate analysis (p = 0.007, 0.047 and 0.045 respectively). HBV DNA and platelet count were predictors of significant fibrosis in HBeAg-negative disease (p = 0.020 and 0.015 respectively). An elevated ALT was not predictive of significant fibrosis for HBeAg-positive (p = 0.345) and -negative (p = 0.544) disease. There was no significant difference in fibrosis staging among ALT 1-2 x upper limit of normal (ULN) and > x 2 ULN for both HBeAg-positive (p = 0.098) and -negative (p = 0.838) disease. CONCLUSION: An elevated ALT does not accurately predict significant liver injury. Decisions on commencing antiviral therapy should not be heavily based on a particular ALT threshold.published_or_final_versio

    Elastic SCAD as a novel penalization method for SVM classification tasks in high-dimensional data

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    <p>Abstract</p> <p>Background</p> <p>Classification and variable selection play an important role in knowledge discovery in high-dimensional data. Although Support Vector Machine (SVM) algorithms are among the most powerful classification and prediction methods with a wide range of scientific applications, the SVM does not include automatic feature selection and therefore a number of feature selection procedures have been developed. Regularisation approaches extend SVM to a feature selection method in a flexible way using penalty functions like LASSO, SCAD and Elastic Net.</p> <p>We propose a novel penalty function for SVM classification tasks, Elastic SCAD, a combination of SCAD and ridge penalties which overcomes the limitations of each penalty alone.</p> <p>Since SVM models are extremely sensitive to the choice of tuning parameters, we adopted an interval search algorithm, which in comparison to a fixed grid search finds rapidly and more precisely a global optimal solution.</p> <p>Results</p> <p>Feature selection methods with combined penalties (Elastic Net and Elastic SCAD SVMs) are more robust to a change of the model complexity than methods using single penalties. Our simulation study showed that Elastic SCAD SVM outperformed LASSO (<it>L</it><sub>1</sub>) and SCAD SVMs. Moreover, Elastic SCAD SVM provided sparser classifiers in terms of median number of features selected than Elastic Net SVM and often better predicted than Elastic Net in terms of misclassification error.</p> <p>Finally, we applied the penalization methods described above on four publicly available breast cancer data sets. Elastic SCAD SVM was the only method providing robust classifiers in sparse and non-sparse situations.</p> <p>Conclusions</p> <p>The proposed Elastic SCAD SVM algorithm provides the advantages of the SCAD penalty and at the same time avoids sparsity limitations for non-sparse data. We were first to demonstrate that the integration of the interval search algorithm and penalized SVM classification techniques provides fast solutions on the optimization of tuning parameters.</p> <p>The penalized SVM classification algorithms as well as fixed grid and interval search for finding appropriate tuning parameters were implemented in our freely available R package 'penalizedSVM'.</p> <p>We conclude that the Elastic SCAD SVM is a flexible and robust tool for classification and feature selection tasks for high-dimensional data such as microarray data sets.</p
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