bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessing the accuracy of predictive models with interval-censored data
Authors: Wu Ying , Cook Richard J 
Published: February 2020

SummaryWe develop methods for assessing the predictive accuracy of a given event time model when the validation sample is comprised of case $K$ interval-censored data. An imputation-based, an inverse probability weighted (IPW), and an augmented inverse probability weighted (AIPW) estimator are developed and evaluated for the mean prediction error and the area under the receiver operating characteristic curve when the goal is to predict event status at a landmark time. The weights used for the IPW and AIPW estimators are obtained by fitting a multistate model which jointly considers the event process, the recurrent assessment process, and loss to follow-up. We empirically investigate the performance of the proposed methods and illustrate their application in the context of a motivating rheumatology study in which human leukocyte antigen markers are used to predict disease progression status in patients with psoriatic arthritis.
Reconsidering the notions of process, order and stability in Veblen
Authors: Martins Nuno Ornelas 
Published: February 2020

Abstract
Tony Lawson has recently provided an original assessment of the notions of process, order and stability in the writings of Thorstein Veblen, in which he attributes to Veblen an ideational conception of order, while also arguing that Veblen changed his views on the causes of stability, which in earlier writings were attributed to institutions and the ceremonial aspects of life, and in later writings are to be found in human nature. In so doing, Lawson moves away from previous interpretations of Veblen, including Lawson’s own in some respects, especially on the nature of institutions. Here I further extend Lawson’s new interpretation of Veblen in some respects, while challenging some aspects of it. In particular, I discuss whether Veblen really changed his view on the causes of stability, while proposing a generalisation of the Veblenian dichotomy.
Structured reviews for data and knowledge-driven research
Authors: Queralt-Rosinach Núria , Stupp Gregory S , Li Tong Shu , Mayers Michael , Hoatlin Maureen E , Might Matthew , Good Benjamin M , Su Andrew I 
Published: February 2020

AbstractHypothesis generation is a critical step in research and a cornerstone in the rare disease field. Research is most efficient when those hypotheses are based on the entirety of knowledge known to date. Systematic review articles are commonly used in biomedicine to summarize existing knowledge and contextualize experimental data. But the information contained within review articles is typically only expressed as free-text, which is difficult to use computationally. Researchers struggle to navigate, collect and remix prior knowledge as it is scattered in several silos without seamless integration and access. This lack of a structured information framework hinders research by both experimental and computational scientists. To better organize knowledge and data, we built a structured review article that is specifically focused on NGLY1 Deficiency, an ultra-rare genetic disease first reported in 2012. We represented this structured review as a knowledge graph and then stored this knowledge graph in a Neo4j database to simplify dissemination, querying and visualization of the network. Relative to free-text, this structured review better promotes the principles of findability, accessibility, interoperability and reusability (FAIR). In collaboration with domain experts in NGLY1 Deficiency, we demonstrate how this resource can improve the efficiency and comprehensiveness of hypothesis generation. We also developed a read–write interface that allows domain experts to contribute FAIR structured knowledge to this community resource. In contrast to traditional free-text review articles, this structured review exists as a living knowledge graph that is curated by humans and accessible to computational analyses. Finally, we have generalized this workflow into modular and repurposable components that can be applied to other domain areas. This NGLY1 Deficiency-focused network is publicly available at http://ngly1graph.org/.Availability and implementationDatabase URL: http://ngly1graph.org/. Network data files are at: https://github.com/SuLab/ngly1-graph and source code at: https://github.com/SuLab/bioknowledge-reviewer.Contactasu@scripps.edu
Development of a 3D human osteoblast cell culture model for studying mechanobiology in orthodontics
Authors: Brezulier Damien , Pellen-Mussi Pascal , Tricot-Doleux Sylvie , Novella Agnès , Sorel Olivier , Jeanne Sylvie 
Published: February 2020

SummaryObjectivesMechanobiology phenomena constitute a major element of the cellular and tissue response during orthodontic treatment and the implantation of a biomaterial. Better understanding these phenomena will improve the effectiveness of our treatments. The objective of this work is to validate a model of three-dimensional (3D) culture of osteoblasts to study mechanobiology.Materials and methodsThe hFOB 1.19 cell line was cultured either traditionally on a flat surface or in aggregates called spheroids. They were embedded in 0.8% low-melting agarose type VII and placed in a polyethylene terephthalate transwell insert. Compressive forces of 1 and 4 g/cm2 were applied with an adjustable weight. Proliferation was evaluated by measuring diameters, monitoring glucose levels, and conducting Hoechst/propidium iodide staining. Enzyme-linked immunosorbent assays focusing on the pro-inflammatory mediators interleukin (IL)-6 and IL-8 and bone remodelling factor osteoprotegerin were performed to evaluate soluble factor synthesis. quantitative reverse transcription-polymerase chain reaction was performed to evaluate bone marker transcription.ResultsThe 3D model shows good cell viability and permits IL dosing. Additionally, three gene expression profiles are analysable.LimitationsThe model allows analysis of conventional markers; larger exploration is needed for better understanding osteoblast mechanobiology. However, it only allows an analysis over 3 days.ConclusionThe results obtained by applying constant compressive forces to 3D osteoblastic cultures validate this model system for exploring biomolecule release and analysing gene transcription. In particular, it highlights a disturbance in the expression of markers of osteogenesis.
Mortality after drug-eluting stents vs. coronary artery bypass grafting for left main coronary artery disease: a meta-analysis of randomized controlled trials
Authors: Ahmad Yousif , Howard James P , Arnold Ahran D , Cook Christopher M , Prasad Megha , Ali Ziad A , Parikh Manish A , Kosmidou Ioanna , Francis Darrel P , Moses Jeffrey W , Leon Martin B , Kirtane Ajay J , Stone Gregg W , Karmpaliotis Dimitri 
Published: February 2020

Abstract

Aims
The optimal method of revascularization for patients with left main coronary artery disease (LMCAD) is controversial. Coronary artery bypass graft surgery (CABG) has traditionally been considered the gold standard therapy, and recent randomized trials comparing CABG with percutaneous coronary intervention (PCI) with drug-eluting stents (DES) have reported conflicting outcomes. We, therefore, performed a systematic review and updated meta-analysis comparing CABG to PCI with DES for the treatment of LMCAD.

Methods and results
We systematically identified all randomized trials comparing PCI with DES vs. CABG in patients with LMCAD. The primary efficacy endpoint was all-cause mortality. Secondary endpoints included cardiac death, myocardial infarction (MI), stroke, and unplanned revascularization. All analyses were by intention-to-treat. There were five eligible trials in which 4612 patients were randomized. The weighted mean follow-up duration was 67.1 months. There were no significant differences between PCI and CABG for the risk of all-cause mortality [relative risk (RR) 1.03, 95% confidence interval (CI) 0.81–1.32; P = 0.779] or cardiac death (RR 1.03, 95% CI 0.79–1.34; P = 0.817). There were also no significant differences in the risk of stroke (RR 0.74, 95% CI 0.35–1.50; P = 0.400) or MI (RR 1.22, 95% CI 0.96–1.56; P = 0.110). Percutaneous coronary intervention was associated with an increased risk of unplanned revascularization (RR 1.73, 95% CI 1.49–2.02; P &lt; 0.001).

Conclusion
The totality of randomized clinical trial evidence demonstrated similar long-term mortality after PCI with DES compared with CABG in patients with LMCAD. Nor were there significant differences in cardiac death, stroke, or MI between PCI and CABG. Unplanned revascularization procedures were less common after CABG compared with PCI. These findings may inform clinical decision-making between cardiologists, surgeons, and patients with LMCAD.
Association Between Erythrocyte Levels of n-3 Polyunsaturated Fatty Acids and Risk of Frailty in Community-Dwelling Older Adults: The Korean Frailty and Aging Cohort Study
Authors: Kim Doyeon , Won Chang Won , Park Yongsoon 
Published: February 2020

Abstract

Background
Inflammation is a major risk factor for frailty, but n-3 polyunsaturated fatty acids (PUFA) has been suggested as an anti-inflammatory agent. The present study aimed to investigate the hypothesis that the higher erythrocyte levels of long-chain n-3 PUFA were associated with lower odds of frailty and frailty criterion.

Methods
Cross-sectional analysis from the Korean Frailty and Aging Cohort Study, a total of 1,435 people aged 70–84 years were included. Sex- and age-stratified community residents, drawn in urban and rural regions nationwide, were eligible for participation in the study. All participants were categorized as frail and nonfrail according to the Cardiovascular Health Study index.

Results
The likelihood of frailty was inversely associated with the erythrocyte levels of eicosapentaenoic acid (EPA; odds ratio [OR] per unit 0.33; 95% confidence interval [CI] 0.14–0.77; p for trend = .002) and docosahexaenoic acid (DHA; OR per unit 0.42; 95% CI 0.20–0.87; p for trend = .018). Among each frailty criterion, the likelihood of slow walking speed was associated with erythrocyte levels of EPA and DHA, and the likelihood of exhaustion was inversely associated with the erythrocyte levels of DHA.

Conclusions
The present study showed that the frailty and frailty criterion were significantly associated with lower erythrocyte levels of long-chain n-3 PUFA, suggesting that lower n-3 PUFA could be a marker for the risk of frailty.
Rigorous analysis of free solution glycosaminoglycan dynamics using simple, new tools
Authors: Nagarajan Balaji , Sankaranarayanan Nehru Viji , Desai Umesh R 
Published: February 2020

Abstract
Heparin/heparan sulfates (H/HS) are ubiquitous biopolymers that interact with many proteins to induce a range of biological functions. Unfortunately, how these biopolymers recognize their preferred protein targets remain poorly understood. It is suggested that computational simulations offer attractive avenues but a number of challenges, e.g., difficulty of selecting a comprehensive force field, few simple tools to interpret data, among others, remain. This work addresses several such challenges so as to help ease the implementation and analysis of computational experiments. First, this work presents a rigorous comparison of two different recent force fields, CHARMM36 and GLYCAM06, for H/HS studies. Second, it introduces two new straightforward parameters, i.e., end-to-end distance and minimum volume enclosing ellipsoid, to understand the myriad conformational forms of oligosaccharides that evolve over time in water. Third, it presents an application to elucidate the number and nature of inter and intramolecular, nondirect bridging water molecules, which help stabilize unique forms of H/HS. The results show that nonspecialists can use either CHARMM36 or GLYCAM06 force fields because both gave comparable results, albeit with small differences. The comparative study shows that the HS hexasaccharide samples a range of conformations with nearly equivalent energies, which could be the reason for its recognition by different proteins. Finally, analysis of the nondirect water bridges across the dynamics trajectory shows their importance in stabilization of certain conformational forms, which may become important for protein recognition. Overall, the work aids nonspecialists employ computational studies for understanding the solution behavior of H/HS.
Ancient Caloric Functions on Graphs With Unbounded Laplacians
Authors: Hua Bobo 
Published: February 2020

Abstract
We study ancient solutions of polynomial growth to both continuous-time and discrete-time heat equations on graphs with unbounded Laplacians. We extend Colding and Minicozzi’s theorem [12] on manifolds and the result [22] on graphs with normalized Laplacians to the setting of graphs with unbounded Laplacians: for a graph admitting an intrinsic metric, which has polynomial volume growth, the dimension of the space of ancient solutions of polynomial growth is bounded by the dimension of harmonic functions with the same growth up to some factor.
Liquid Chromatographic Method for Determination of Cyhexatin in Technical and Formulated Products: Collaborative Study
Authors: Lupan Stephen 
Published: February 2020

Abstract
Cyhexatin technical (95%), 25 and 50% wettable powders, and a 600 g/L suspension concentrate were analyzed by liquid chromatography in a collaborative study of the method. Paired samples of cyhexatin technical and the 3 formulations were extracted with a mixture of methanol-water-acetic acid (950 + 49 + 1) containing n-decylbenzene as internal standard. Components were separated on a Lichrosorb RP-18 column using methanol-water-HCl-NaCl (93 + 7 + 0.001M + 0.005M) at 2.0 mL/min, and then detected at 214 nm. Results were received from 18 of the 20 laboratories who agreed to participate in the study; 14 sets of data were suitable for statistical evaluation. Repeatability coefficients of variation (CV0 ranged from 0.46% for the 50% wettable powder to 1.14% for the suspension concentrate. Reproducibility coefficients of variation (CVX) ranged from 0.70 to 1.85% for the 4 types of samples. The method has been adopted official first action as a CIPAC-AOAC method.
Liquid Chromatographic Method for Determination of Piperine in Piper nigrum (Black and White Pepper)
Authors: Weaver Kenneth M , Neale Michael E , Laneville Ann 
Published: February 2020

Abstract
A method was developed for the detection and quantitation of piperine in Piper nigrum. A reverse-phase liquid chromatographic system equipped with a C18 column with detection at 340 nm was used. A rapid 1 h acetone extraction followed by solvent dilution was used to avoid sample cleanup. The detection limit is 3 ng injected piperine, with 97.5-100.5% recovery of added piperine.
Statistical Sampling Approaches
Authors: Springer Janet A , Mcclure Foster D 
Published: February 2020

Abstract
This article describes basic sampling principles and the application of statistical sampling techniques to specific problems encountered in the Food and Drug Administration (FDA). Concepts are emphasized, and theory is minimized. The basic principles of sampling from a normal and binomial population, including confidence interval calculation and sample size determination, are briefly reviewed. Stratified, random, systematic, and judgment sampling are explained. Operating characteristic curves for attribute (and perhaps variable) sampling for acceptance of lots are derived and applied to specific FDA problems. The advantages and disadvantages of single and multiple sampling plans and plans which address multiple classes of criteria such as major and minor defects are discussed. Sampling schedules such as MIL-STD-105D and Canada's Government Specifications Board CGSB-105-GP-1 are reviewed to familiarize readers with the principles involved in these plans and to give them an idea of how they could be applied to FDA problems.
In Vitro Analytical System for Determining the Ability of Antibiotics at Residue Levels to
Select for Resistance in Bacteria
Authors: Suebrady Marietta , Strobel Robert J , Katz Stanley E 
Published: February 2020

Abstract
An analytical procedure, based on the concept that exposure of bacteria to antibiotics will result in the selection of a resistant population, was developed. Two strains of enteric bacteria, Escherichia coli CS-1 and Enterobacter cloacae B520, which are sensitive to a wide variety of antibiotics, were used as the test organisms. E. coli CS-1 were exposed to 1.00 μg antibiotic or antimicrobial/mL; E. cloacae B520 were exposed to 0.01, 0.10, 0.50,1.00, and 5.00 μg/mL. Both organisms developed increased resistance to other antibiotics after exposure to chlortetracycline and oxytetracycline, as measured by the minimum inhibitory concentration (MIC). E. cloacae B520 showed increased resistance to ampicillin, oxytetracycline, and chloramphenicol after exposure to levels as low as 0.10 μg/mL. Exposure to streptomycin, sulfamethazine, tylosin, bacitracin, flavomycin, virginiamycin, and monensin at levels of 1.00 μg/mL did not increase the MIC. Exposure to 5.00 *tg streptomycin, sulfamethazine, tylosin, and monensin/mL increased the MIC ofE. cloacae to one of the antibiotic markers. These increased MICs exceeded the 95% confidence limits of the MIC values of the unexposed organisms.
Liquid Chromatographic Determination of Phenolic Impurities in Technical MCPA Using
Electrochemical Detection (Coulometric Mode)
Authors: Wigfield Yuk Y , Lanouette Monique 
Published: February 2020

Abstract
Fifteen samples of technical 4-chloro-2-methylphenoxy acetic acid (MCPA) from 6 manufacturers were analyzed for the presence of 13 different phenolic impurities. Reverse-phase liquid chromatography with an electrochemical (coulometric mode) detector was used for qualitative and quantitative determinations. The phenols were separated using a 40-70% methanol and 60-30% 0.02M KH2P04 (pH 4.0) 35 min gradient system on a Spheri-5-RP-18 column. Confirmation of the phenols present was done by retention time comparison with the corresponding standards, using 2 other isocratic mobile phases, methanol-0.2M acetic acid (60 + 40) at a flow rate of 1.3 mL/min and acetonitrile-0.02M KH2P04 (45 + 55) (pH 3.0) at a flow rate of 0.90 mL/min. The similarity of results on 3 different solvent systems demonstrates the absence of any interfering responses. 2-Methyl-4-chlorophenol (average 0.168%) and 2-methyl- 4,6-dichlorophenol (average 0.004%) were detected in all 15 samples. 3-Methylphenol (0.002%) and 2,6-dimethyl-4-chlorophenol (0.002%) were detected in one sample only. The minimum detectable amount ranged from 0.1 to 0.6 ng, depending on the phenol. This corresponds to less than 0.002% when expressed relative to the weight of sample. The coefficient of variation for multiple analyses of the same sample (n = 6) is 1% for 2-methyl-4-chlorophenol and 3% for 2-methy 1-4,6- dichlorophenol.
Simple Determination of Ranitidine in Dosage Forms by In-Phase Selective AC Polarography
Authors: Squella Juan A , Zuñiga Luis A , Lemus Igor , Vergara Luis J. Nuñez 
Published: February 2020

Abstract
A new AC polarographic method for the determination of pharmaceutical forms of ranitidine is proposed, based on the electroactivity of the ranitidine nitro group. Individual and composite assays as well as recovery studies are described. Results show adequate precision and accuracy. Sample preparation is easy and no excipient separation is required.
Liquid Chromatographic Quantitation of Chicken and Turkey in Unheated Chicken-Turkey Mixtures
Authors: Ashoor Samy H , Osman Magdi A 
Published: February 2020

Abstract
A simple and rapid liquid chromatographic (LC) method has been used to quantitate chicken and turkey in unheated chicken-turkey mixtures. The LC method is sensitive and detects as little as 1% chicken or turkey. It reliably quantitates 5-100% chicken or turkey in unheated poultry mixtures. The method applies also to chicken or turkey which has been frozen, but does not apply to heat-treated poultry meats.
Liquid Chromatographic Determination of Tetracycline Residues in Animal Feeds
Authors: Martinez Elizabeth E , Shimoda Wilbert 
Published: February 2020

Abstract
A liquid chromatographic method for the multiresidue determination of tetracyclines (TCs) in feeds is described. The levels of quantitation were 10 ppm each for tetracycline-HCl (TC), oxytetracycline (OTC), and chlortetracycline-HCl (CTC); the detection limit was 40 ppb for each. The calibration curves were linear between 2.5 and 100 ppm. The procedure involved double extraction with pH 2.0 and pH 4.5 Mcllvain buffers, cleanup on a Sephadex LH-20 column, separation on a Nova-Pak C18 column, and detection at 370 nm. Recoveries of 10 μg/g of each TC in multiresidue feed samples ranged from 55.8 to 75.5% for OTC, 71.6 to 100% for TC, and 22.4 to 60.6% for CTC. The identities of the TCs were confirmed by thin layer chromatography.
Reverse-Phase Liquid Chromatographic Determination of Dexamethasone Acetate and
Cortisone Acetate in Bulk Drug Substance and Dosage Forms: Collaborative Study
Authors: Ng Linda L 
Published: February 2020

Abstract
A reverse-phase liquid chromatographic method for determination of dexamethasone acetate and of cortisone acetate was subjected to an interlaboratory study by 8 collaborators for each steroid acetate. Bulk drug substance, suspensions, and tablets were assayed. Bulk drug or dosage form is dissolved in an acetonitrile-buffer mixture and analyzed by an external standard method. The steroid acetate is resolved from extraneous components by reverse-phase chromatography and detected at 254 nm. The sample solutions are stable for at least 72 h. For dexamethasone acetate, coefficients of variation were 0.9 and &lt;3.1% for the bulk drug substance and the suspensions, respectively. For cortisone acetate, coefficients of variation were 0.7% for bulk material, &lt;2.0% for suspensions, and &lt;2.5% for tablets. All dosage forms were commercial formulations. The 2 methods have been adopted official first action
Determination of Formaldehyde and Other Aldehydes in Industrial Surfactants hy Liquid
Chromatographic Separation of Their Respective 2,4-Dinitrophenylhydrazone Derivatives
Authors: Dahlgran James R , Jameson Melvin N 
Published: February 2020

Abstract
A rapid and simple method for the determination of formaldehyde, acetaldehyde, and propionaldehyde in surfactants by derivatization with 2,4-dinitrophenylhydrazine (DNPH) has been developed. Samples are prepared in small vials containing a solution of DNPH and acetonitrile. This procedure allows direct injection of an aliquot of the sample into a liquid chromatograph (LC) for analysis. Separation and quantitation of the derivatives can be performed using reversephase liquid chromatography. Detection limits for formaldehyde, acetaldehyde, and propionaldehyde are 0.1, 0.1, and 0.5 pg/g, respectively, for a 1 g sample of the surfactant. The technique has been applied to other ethoxylated and propoxylated polymeric materials with equal success
Enantiomer Resolution and Assay of Propionic Acid-Derived Herbicides in Formulations by
Using Chiral Liquid Chromatography and Achiral Gas Chromatography
Authors: MÜller Markus D , Bosshardt Hans-Paul 
Published: February 2020

Abstract
Enantiomers of 6 propionic acid-derived herbicides in the form of their esters were resolved using liquid chromatography with a chiral column. Free acids are converted to methyl esters by means of a BF3- catalyzed reaction. Chromatographic resolutions for 6 of 8 herbicides investigated were in the range of 2 to 4. The method was applied for the simultaneous determination of mecoprop and 2,4-D content and individual mecoprop enantiomers in 2 formulations containing racemic and R-mecoprop in mixture with 2,4-D. Precision and accuracy of content determination was comparable to standard methods, and enantiomer contents were in good agreement with declared values. The enantiomers of dichlorprop and mecoprop were also resolved as diastereomeric menthyl esters by achiral high resolution gas chromatography (HRGC). HRGC data on enantiomer composition were in good agreement with those from the LC method and other data