bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-Performance Liquid Chromatographic Determination of Memantine in Human Urine Following Solid-Phase Extraction and Precolumn Derivatization
Authors: Michail Karim , Daabees Hoda , Beltagy Youssef , Elkhalek Magdy Abd , Khamis Mona 
Published: November 2013

Abstract
A validated HPLC-UV method is presented for the quantification of urinary memantine hydrochloride, a novel medication approved to treat moderate and advanced cases of Alzheimer's disease. The drug and amantadine hydrochloride, the internal standard, were extracted from human urine using SPE. The extract was then buffered and derivatized at room temperature using o-phthalaldehyde in the presence of N-acetyl-L-cyteine. Chromatographic separation of the formed derivatives was achieved on a C18 column using methanol–water mobile phase adjusted to pH 7 and pumped isocratically at 1 mL/min. The UV detector was set at 340 nm. The chromatographic run time did not exceed 10 min. The LOD and LOQ were 8 and 20 ng/mL, respectively. The RSDs for intraday and interday precisions did not exceed 5.5%. The method was used to monitor memantine hydrochloride in human urine in order to determine an appropriate sampling interval for future noninvasive therapeutic drug monitoring. The assay could also be applied to the determination of amantadine. The described assay showed that a postdosing time interval of 25–75 h seems adequate for sampling and monitoring memantine in urine.
Simultaneous Determination of Furfural, Acetic Acid, and 5-Hydroxymethylfurfural in Corncob Hydrolysates Using Liquid Chromatography with Ultraviolet Detection
Authors: Dong Bo-Yu , Chen Ye-Fu , Zhao Chang-Chun , Zhang Shi-Jie , Guo Xue-Wu , Xiao Dong-Guang 
Published: November 2013

Abstract
A single-laboratory validation study was conducted using HPLC for detecting and quantifying acetic acid, furfural, and 5-hydroxymethylfurfural (HMF) in corncob hydrolysates. A pretreatment procedure using dilute sulfuric acid was optimized for corncob hydrolysis. The final hydrolysates were analyzed by HPLC using a C18RP column with aqueous 0.01% (v/v) H2SO4–CH3OH (95 + 5) as the mobile phase at a flow rate of 1 mL/min. The wavelengths for detecting the three compounds were changed to their optimal UV detection wavelengths at the time of elution. The wavelength detection adjustments were as follow: 205 nm (0 to 4 min); 284 nm (4 to 7 min); and 276 nm (7 to 10 min). Separation was achieved with a chromatographic run time of 10 min. The calibration curves for the three compounds had correlation coefficients (r2) ≥99.8%. The analytical range, as defined by the calibration curves, was 0.5–10 mg/L for acetic acid, 0.4–22 mg/L for furfural, and 0.1–18 mg/L for HMF. The LODs for acetic acid, furfural, and HMF were estimated to be 0.05, 0.03, and 0.02 mg/L, respectively; the LOQs were 0.196, 0.135, and 0.074 mg/L, respectively. The RSD values for the intraday precision study ranged from 0.31 to 2.22%, and from 0.57 to 2.43% for the interday study. The mean recovery rates in all compounds were between 100.08 and 101.49%.
Determination of Erythromycin in Medicated Salmonid Fish Feed by Liquid Chromatography and UV Spectroscopy
Authors: De Alwis Hemakanthi G , Girard Lauren , Kijak Philip J , Rummel Nathan 
Published: November 2013

Abstract
A simple, robust LC-UV method was developed to assay erythromycin in medicated salmonid feed. In this method, erythromycin was extracted from feed with acetonitrile and water, cleaned up by SPE, evaporated to dryness, reconstituted, and analyzed by LC-UV. The resulting method produced high accuracy, 82–90%, for both salmon and trout feed that represented varied pellet sizes and ingredient amounts. The intraday and interday precisions, at ≤6 and 5%, respectively, indicated the method's good repeatability. Calibration was linear over the range of drug concentrations typically used in medicated feed. An independent analyst validation further demonstrated the repeatability of the method. The developed method could support the drug approval process for erythromycin in medicated salmonid fish feed.
Determination of Total Antioxidant Capacity by Oxygen Radical Absorbance Capacity (ORAC) Using Fluorescein as the Fluorescence Probe: First Action 2012.23
Authors: Ou Boxin , Chang Tony , Huang Dejian , Prior Ronald L 
Published: November 2013

Abstract
An improved method for the measurement of oxygen radical absorbance capacity (ORAC) was developed and validated using fluorescein (3′,6′-dihydroxyspiro[isobenzofuran-1[3H], 9′[9H]-xanthen]-3-one) as a new fluorescence probe (ORACFL). Randomly methylated β-cyclodextrin (RMCD) was introduced as the water-solubility enhancer for lipophilic antioxidants. 7% RMCD (w/v) in 50% acetone–H2O mixture sufficiently solubilized vitamin E compounds and other lipophilic phenolic antioxidants in 75 mM phosphate buffer (pH 7.4). Results indicated that fluorescein shows excellent photostability under the plate reader conditions. This ORACFL was validated through linearity, precision, accuracy, and ruggedness. The validation results demonstrated that the ORACFL assay is reliable and robust. The mean of intraday and interday CVs were &lt;15%; for hydrophilic ORAC, LOD and LOQ are 5 and 6.25 μM, respectively; for lipophilic ORAC, LOD and LOQ are 6.25 and 12.5 μM, respectively. It is concluded that unlike other popular methods, the ORACFL assay provides a direct measure of total antioxidant capacity against the peroxyl radicals.
The Use of TLC-DPPH• Test with Image Processing to Study Direct Antioxidant Activity of Phenolic Acid Fractions of Selected Lamiaceae Family Species
Authors: Cieśla Łukasz , Staszek Dorota , Kowalska Teresa , Waksmundzka-Hajnos Monika 
Published: November 2013

Abstract
TLC coupled with 2,2-diphenyl-1-picrylhydrazyl staining was used to analyze phenolic acid fractions of selected Salvia and Thymus species. Documented videoscans were processed by means of an image processing program. This is the first time that free phenolic acids fractions, as well as fractions containing phenolic acids derived from basic and acidic hydrolysis, have been analyzed and compared for selected sage and thyme species. The analyzed samples along with caffeic acid (CA; standard) were chromatographed on silica gel plates with toluene – ethyl acetate – formic acid (60 + 40 + 1, v/v/v) mobile phase. The extracts were investigated with respect to the activity of CA. It was found that CA was most abundant in the fractions derived from basic hydrolysis. This compound was not detected in any of the fractions obtained after acidic hydrolysis. S. officinalis and S. triloba have similar free radical scavenging activity fingerprints obtained for all the analyzed fractions.
Sampling Modality Influences the Predictive Value of Grading in Adult Soft Tissue Extremity Sarcomas
Authors: Khoja Hatim , Griffin Anthony , Dickson Brendan , Wunder Jay , Ferguson Peter , Howarth David , Kandel Rita 
Published: November 2013

Context.—Histologic grade is one of the best predictors of outcome in adult soft tissue sarcomas. Current grading systems were validated on resection specimens; however, there has been a trend toward the use of biopsies to diagnosis these tumors.
Objectives.—To determine whether the grade of an extremity soft tissue sarcoma determined on tissue obtained by either core needle biopsy or incisional biopsy is predictive of metastasis- or disease-free survival, and whether either sampling modality is superior.
Design.—One hundred three core needle biopsies and 107 incisional biopsies of nonmetastatic spindle cell sarcomas of the extremities were retrieved from the archives. All cases had a minimum 2-year follow-up. Patient data and outcome and tumor characteristics were recorded. Tumors were reviewed and evaluated using the French Federation of Cancer Centers Sarcoma Group grading system. Kaplan-Meier survival curves were generated to correlate tumor grade with metastasis- and disease-free survival for both groups.
Results.—Patient and tumor characteristics were similar between groups except that more tumors were grade 3 and superficial in the incisional biopsy group. Grade determined on core needle biopsy was not predictive of either metastasis-free survival (P = .59) or disease-free survival (P = .50). In contrast, grade determined on incisional biopsy was predictive of both metastasis-free survival (P &lt; .001) and disease-free survival (P = .001).
Conclusions.—Biopsy, particularly core needle biopsy, represents a convenient diagnostic tool, particularly in the context of neoadjuvant therapy. However, based on these results incisional biopsy is recommended if grading is to be used to predict prognosis in spindle cell soft tissue sarcomas of the extremities.
Detection of short‐term slow slip events along the Nankai Trough via groundwater observations
Authors: Kitagawa Yuichi , Koizumi Naoji 
Published: November 2013

AbstractIn order to develop new tools or techniques to detect short‐term slow slip events (S‐SSEs) along subduction zones, we attempted to detect S‐SSEs by conducting groundwater pressure observations. At ANO station, which is a groundwater observation station operated by the Geological Survey of Japan, the National Institute of Advanced Industrial Science and Technology, for earthquake prediction research, groundwater pressures changed due to six S‐SSEs that occurred near ANO from June 2011 to April in 2013. The fault models of these S‐SSEs, which were estimated mainly by observing the crustal strains and tilts, explained the changes in the groundwater pressures. If the strain sensitivity of the observed groundwater pressure or level is larger than 1 mm/nstrain and the noise level is smaller than 50 mm/day, it is possible to detect S‐SSEs that occur in southwest Japan by conducting groundwater pressure or level observations.
Vulnerability of shallow subarctic lakes to evaporate and desiccate when snowmelt runoff is low
Authors: Bouchard F. , Turner K. W. , MacDonald L. A. , Deakin C. , White H. , Farquharson N. , Medeiros A. S. , Wolfe B. B. , Hall R. I. , Pienitz R. , Edwards T. W. D. 
Published: November 2013

AbstractSnowmelt is a crucial source of water for many shallow subarctic lakes, but climate models predict that snowfall will decrease in some regions, with profound ecological consequences. Here we use lake water isotope data across gradients of terrestrial vegetation cover (open tundra to closed forest) and topographic relief to identify lakes that are vulnerable to desiccation under conditions of low snowmelt runoff in two subarctic landscapes—Old Crow Flats, Yukon, and Hudson Bay Lowlands, Manitoba (Canada). Lakes located in low‐relief, open tundra catchments in both landscapes displayed a systematic, positive offset between directly measured lake water δ18O over multiple sampling campaigns and lake water δ18O inferred from cellulose in recently deposited surface sediments. We attribute this offset to a strong evaporative 18O‐enrichment response to lower‐than‐average snowmelt runoff in recent years. Notably, some lakes underwent near‐complete desiccation during midsummer 2010 following a winter of very low snowfall. Based on the paleolimnological record of one such lake, the extremely dry conditions in 2010 may be unprecedented in the past ~200 years. Findings fuel concerns that a decrease in snowmelt runoff will lead to widespread desiccation of shallow lakes in these landscapes.
Nonheme Iron Mediated Oxidation of Light Alkanes with Oxone: Characterization of Reactive Oxoiron(IV) Ligand Cation Radical Intermediates by Spectroscopic Studies and DFT Calculations
Authors: Tse Chun‐Wai , Chow Toby Wai‐Shan , Guo Zhen , Lee Hung Kay , Huang Jie‐Sheng , Che Chi‐Ming 
Published: November 2013

AbstractThe oxidation of light alkanes that is catalyzed by heme and nonheme iron enzymes is widely proposed to involve highly reactive {FeVO} species or {FeIVO} ligand cation radicals. The identification of these high‐valent iron species and the development of an iron‐catalyzed oxidation of light alkanes under mild conditions are of vital importance. Herein, a combination of tridentate and bidentate ligands was used for the generation of highly reactive nonheme {FeO} species. A method that employs [FeIII(Me3tacn)(Cl‐acac)Cl]+ as a catalyst in the presence of oxone was developed for the oxidation of hydrocarbons, including cyclohexane, propane, and ethane (Me3tacn=1,4,7‐trimethyl‐1,4,7‐triazacyclononane; Cl‐acac=3‐chloro‐acetylacetonate). The complex [FeIII(Tp)2]+ and oxone enabled stoichiometric oxidation of propane and ethane. ESI‐MS, EPR and UV/Vis spectroscopy, 18O labeling experiments, and DFT studies point to [FeIV(Me3tacn)({Cl‐acac}.+)(O)]2+ as the catalytically active species.
Crowdsourcing Natural Products Discovery to Access Uncharted Dimensions of Fungal Metabolite Diversity
Authors: Du Lin , Robles Andrew J. , King Jarrod B. , Powell Douglas R. , Miller Andrew N. , Mooberry Susan L. , Cichewicz Robert H. 
Published: November 2013

AbstractA fundamental component for success in drug discovery is the ability to assemble and screen compounds that encompass a broad swath of biologically relevant chemical‐diversity space. Achieving this goal in a natural‐products‐based setting requires access to a wide range of biologically diverse specimens. For this reason, we introduced a crowdsourcing program in which citizen scientists furnish soil samples from which new microbial isolates are procured. Illustrating the strength of this approach, we obtained a unique fungal metabolite, maximiscin, from a crowdsourced Alaskan soil sample. Maximiscin, which exhibits a putative combination of polyketide synthase (PKS), non‐ribosomal peptide synthetase (NRPS), and shikimate pathway components, was identified as an inhibitor of UACC‐62 melanoma cells (LC50=0.93 μM). The metabolite also exhibited efficacy in a xenograft mouse model. These results underscore the value of building cooperative relationships between research teams and citizen scientists to enrich drug discovery efforts.
Regional Distribution of Adult Rheumatologists
Authors:   American College of Rheumatology Committee on Rheumatology Training and Workforce Issues
Published: November 2013

ObjectiveTo analyze the distribution of rheumatology practices in the US and factors associated with that distribution, in order to better understand the supply of the rheumatology workforce.MethodsUsing the American College of Rheumatology membership database, all practicing adult rheumatologist office addresses were mapped with ArcView software. The number of rheumatologists per Core Based Statistical Area (CBSA) was calculated. To investigate whether sociodemographic factors correlated with clustering of rheumatologists, covariates from the 2010 US Census for each CBSA, including age, sex, race/ethnicity, and median household income, were modeled.ResultsMany CBSAs, predominantly smaller micropolitan areas, did not have a practicing rheumatologist. For some of these smaller micropolitan areas (with populations of at least 40,000), the closest practicing rheumatologist was more than 200 miles away. However, we also identified several more‐populous areas (populations of 200,000 or more) without a practicing rheumatologist. Greater numbers of rheumatologists were more likely to practice in areas with higher population densities and higher median incomes. More rheumatologists were also found in CBSAs in which there were rheumatology training programs.ConclusionThese findings demonstrate that many smaller regions of the country have no or few practicing adult rheumatologists. Patients with chronic rheumatic conditions in these areas likely have limited access to rheumatology care. Policy changes could address potential regional rheumatology workforce shortages, but limitations of the current data would need to be addressed prior to implementation of such changes.
Multi‐Consensus of Nonlinearly Networked Multi‐Agent Systems
Authors: Li Juan , Guan Zhi‐Hong , Chen Guanrong 
Published: November 2013

AbstractIn this paper, a multi‐consensus problem for networked multi‐agent systems in a weighted and directed graph with a nonlinear protocol is investigated. By using convergence theory, matrix theory and the method of Lyapunov functions, a sufficient condition for the networked multi‐agent systems to achieve multi‐consensus is derived. And the agreement of each group is studied. A feedback controller for the networked multi‐agent systems is then designed to drive the system to achieve multi‐consensus. Numerical simulations illustrate the effectiveness of the theoretical results.
ABCB1 haplotype influences the sirolimus dose requirements in Chinese renal transplant recipients
Authors: Lee Jun , Huang Hongfeng , Chen Ying , Lu Xiaoyang 
Published: November 2013

ABSTRACTSirolimus, an immunosuppressive drug used to prevent organ rejection after renal transplantation, has a narrow therapeutic index and a large inter‐individual variability of pharmacokinetics. The aim of this study was to analyse the dose‐normalized trough blood concentrations (C0/D ratio) of sirolimus in patients with different genotypes and attempt to investigate the possible associations between ABCB1/CYP3A5 genotypes and sirolimus dose requirements in Chinese renal transplant recipients. Blood samples were collected from 85 Chinese renal transplant recipients who were treated with sirolimus for at least 3 months and polymorphisms of the ABCB1 and CYP3A5 were determined by the SNaPShot multiplex assay. The blood concentrations of sirolimus were determined with HPLC. A significant allele‐dependent effect was observed between the CYP3A5*3 polymorphism and the C0/D ratio of sirolimus. The patients bearing at least one CYP3A5*1 allele had a lower sirolimus C0/D ratio compared with those with a homozygous CYP3A5*3 genotype (p < 0.05). No significant differences of sirolimus C0/D ratios were observed among various ABCB1 1236C>T, 2677G>T/A and 3435C>T genotype groups. However, haplotype analysis including ABCB1 1236C>T, 2677G>T/A and 3435C>T SNPs showed that the mean sirolimus C0/D of subjects carrying the CGC/CGC diplotype was about 30% lower compared with those carrying the CGC/TTT or TTT/TTT diplotype, whether or not they expressed the CYP3A5 (p < 0.05). These results demonstrated that the haplotype of ABCB1 might be a better index for the prediction of sirolimus blood concentration than single SNPs. Genotyping of ABCB1 and CYP3A5 might help to optimize individualized sirolimus treatments for Chinese renal transplant recipients. Copyright © 2013 John Wiley & Sons, Ltd.
Flow‐injection chemiluminescence determination of acetylsalicylic acid based on its enhancing effect on the lucigenin–hydrogen peroxide system
Authors: Wabaidur S. M. , Alam S. M. , Alothman Z. A. , Eldesoky Gaber 
Published: November 2013

ABSTRACTA sensitive flow‐injection chemiluminescence method for the determination of acetylsalicylic acid is described. It is based on the enhanced chemiluminescent emission of the alkaline lucigenin–H2O2 system by acetylsalicylic acid. The difference in chemiluminescent intensity of alkaline lucigenin–H2O2 in the presence of acetylsalicylic acid from that in the absence of acetylsalicylic acid was linear at acetylsalicylic acid concentrations in the range of 0.0029–47.37 µg/mL, with detection and quantification limits of 0.0011 and 0.0029 µg/mL, respectively. The correlation coefficient of the working curve was 0.9983. The relative standard deviation (n = 10) for 25 µg/mL acetylsalicylic acid is 1.95%. All experimental parameters were optimized. The method was successfully applied to the determination of acetylsalicylic acid in pharmaceutical preparations. The recovery results obtained by the method were satisfactory. Copyright © 2013 John Wiley & Sons, Ltd.
A nomogram to calculate the Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM)
Authors: Williams D J , Walker J D 
Published: November 2013

Abstract

Background
The Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (POSSUM) is a well validated model for the prediction of perioperative mortality and morbidity with application to surgery and intensive care medicine. The outcome measure calculations are time-consuming, complex and potentially error-prone. Nomograms are low-cost easy-to-use graphic devices that can be used to make repeated calculations to an acceptable level of accuracy for most clinical purposes. This paper describes a nomogram to aid calculation of POSSUM scores.

Methods
This graphic solution consists of two sections: a tally sheet to calculate physiological and operative severity scores (PS and OS), and a nomogram to calculate mortality and morbidity. The latter was designed using standard mathematical methods, and drafted with the aid of commercially available software. Accuracy was confirmed by using a spreadsheet to generate 120 random sets of simulated values for PS and OS, and corresponding calculated values for predicted mortality and morbidity. The outcome values in each case were derived using the nomogram and compared with the spreadsheet values using Bland–Altman analysis.

Results
Bland–Altman analysis showed close agreement between nomogram and spreadsheet. Bias of the nomogram was −0·1 percentage points for mortality and 0·1 percentage points for morbidity, with limits of agreement of −2·1 to +1·9 and −1·4 to +1·6 percentage points for mortality and morbidity respectively. Correlation coefficients were r &gt; 0·999 and P &lt; 0·001 for both mortality and morbidity.

Conclusion
The nomogram provides a rapid, accurate, low-cost means of performing, visualizing and cross-checking POSSUM calculations.
Expression of FAP, ADAM12, WISP1, and SOX11 is heterogeneous in aggressive fibromatosis and spatially relates to the histologic features of tumor activity
Authors: Misemer Benjamin S. , Skubitz Amy P. N. , Carlos Manivel J. , Schmechel Stephen C. , Cheng Edward Y. , Henriksen Jonathan C. , Koopmeiners Joseph S. , Corless Christopher L. , Skubitz Keith M. 
Published: November 2013

AbstractAggressive fibromatosis (AF) represents a group of tumors with a variable and unpredictable clinical course, characterized by a monoclonal proliferation of myofibroblastic cells. The optimal treatment for AF remains unclear. Identification and validation of genes whose expression patterns are associated with AF may elucidate biological mechanisms in AF, and aid treatment selection. This study was designed to examine the protein expression by immunohistochemistry (IHC) of four genes, ADAM12, FAP, SOX11, and WISP1, that were found in an earlier study to be uniquely overexpressed in AF compared with normal tissues. Digital image analysis was performed to evaluate inter‐ and intratumor heterogeneity, and correlate protein expression with histologic features, including a histopathologic assessment of tumor activity, defined by nuclear chromatin density ratio (CDR). AF tumors exhibited marked inter‐ and intratumor histologic heterogeneity. Pathologic assessment of tumor activity and digital assessment of average nuclear size and CDR were all significantly correlated. IHC revealed protein expression of all four genes. IHC staining for ADAM12, FAP, and WISP1 correlated with CDR and was higher, whereas SOX11 staining was lower in tumors with earlier recurrence following excision. All four proteins were expressed, and the regional variation in tumor activity within and among AF cases was demonstrated. A spatial correlation between protein expression and nuclear morphology was observed. IHC also correlated with the probability of recurrence following excision. These proteins may be involved in AF pathogenesis and the corresponding pathways could serve as potential targets of therapy.