bluuebunny/crossref_metadata_2025 huggingface dataset:
No Change in Surgical and Hospitalization Trends Despite Higher Exposure to Anti-Tumor Necrosis Factor in Inflammatory Bowel Disease in the Québec Provincial Database From 1996 to 2015
Authors: Verdon Christine , Reinglas Jason , Coulombe Janie , Gonczi Lorant , Bessissow Talat , Afif Waqqas , Vutcovici Maria , Wild Gary , Seidman Ernest G , Bitton Alain , Brassard Paul , Lakatos Peter L
Published: July 2020

Background

Crohn disease (CD) and ulcerative colitis (UC) have high health care expenditures because of medications, hospitalizations, and surgeries. We evaluated disease outcomes and treatment algorithms of patients with inflammatory bowel disease (IBD) in Québec, comparing periods before and after 2010.

Methods

The province of Québec’s public health administrative database was used to identify newly diagnosed patients with IBD between 1996 and 2015. The primary and secondary outcomes included time to and probability of first and second IBD-related hospitalizations, first and second major surgery, and medication exposures. Medication prescriptions were collected from the public prescription database.

Results

We identified 34,644 newly diagnosed patients with IBD (CD = 59.5%). The probability of the first major surgery increased after 2010 in patients with CD (5 years postdiagnosis before and after 2010: 8% [SD = 0.2%] vs 15% [SD = 0.6%]; P < 0.0001) and patients with UC (6% [SD = 0.2%] vs 10% [SD = 0.6%] ;P < 0.0001). The probability of the second major surgery was unchanged in patients with CD. Hospitalization rates remained unchanged. Patients on anti-tumor necrosis factor (anti-TNF) medications had the lowest probability of hospitalizations (overall 5-year probability in patients with IBD stratified by maximal therapeutic step: 5-aminosalicylic acids 37% [SD = 0.6%]; anti-TNFs 31% [SD = 1.8%]; P < 0.0001). Anti-TNFs were more commonly prescribed for patients with CD after 2010 (4% [SD = 0.2%] vs 16% [SD = 0.6%]; P < 0.0001) in the public health insurance plan, especially younger patients. Corticosteroid exposure was unchanged before and after 2010. Immunosuppressant use was low but increased after 2010. The use of 5-ASAs was stable in patients with UC but decreased in patients with CD.

Conclusions

The probability of first and second hospitalizations remained unchanged in Québec and the probability of major surgery was low overall but did increase despite the higher and earlier use of anti-TNFs.
Persistent COVID-19 in an Immunocompromised Patient Temporarily Responsive to Two Courses of Remdesivir Therapy
Authors: Helleberg Marie , Niemann Carsten Utoft , Moestrup Kasper Sommerlund , Kirk Ole , Lebech Anne-Mette , Lane Clifford , Lundgren Jens
Published: July 2020

The antiviral drug remdesivir has been shown clinically effective for treatment of COVID-19. We here demonstrate suppressive but not curative effect of remdesivir in an immunocompromised patient. A man in his fifties treated with chemoimmunotherapy for chronic lymphocytic leukemia experienced a 9-week course of COVID-19 with high fever and severe viral pneumonia. During two 10-day courses of remdesivir starting 24 and 45 days after fever onset, pneumonia and spiking fevers remitted, but relapsed after discontinuation. Kinetics of temperature, C-reactive protein, and lymphocyte counts mirrored the remitting/relapsing SARS-CoV-2 infection. Combination therapy or longer treatment duration may be needed in immunocompromised patients.
Accelerated Solvent Extraction of Vitamin K1 in Medical Foods in Conjunction with Matrix Solid-Phase Dispersion
Authors: Chase G William , Thompson Brian
Published: July 2020

An extraction technique is described for vitamin K1 in medical foods, using accelerated solvent extraction (ASE) in conjunction with matrix solid-phase dispersion (MSPD). The medical food sample is treated as it would be with MSPD extraction, followed by ASE for a hands-free automated extraction. The vitamin K1 in the ASE extract is then quantitated by reversed-phase liquid chromatography with fluorescence detection. The chromatography specifications are identical to those in previous work that used MSPD only, with a limit of detection of 6.6 pg and a limit of quantitation of 22 pg on column. Recoveries, which were determined for an analyte-fortified zero control reference material for medical foods, averaged 97.6% (n = 25) for vitamin K1. The method provides a rapid, automatic, specific, and easily controlled assay for vitamin K1 in fortified medical foods with minimal solvent usage.
Determination of Lead, Cadmium, Zinc, Copper, and Iron in Foods by Atomic Absorption Spectrometry after Microwave Digestion: NMKL1 Collaborative Study
Authors: Jorhem Lars , Engman Joakim ,   Collaborators:, Arvidsson B-M , Åsman B , Åstrand C , Gjerstad K O , Haugsnes J , Heldal V , Holm K , Jensen A M , Johansson M , Jonsson L , Liukkonen-Lilja H , Niemi E , Thorn C , Utterström K , Venäläinen E-R , Waaler T
Published: July 2020

A method for determination of lead, cadmium, zinc, copper, and iron by atomic absorption spectrometry (AAS) after microwave digestion was subjected to a collaborative study in which 16 laboratories participated [including users of inductively coupled plasma (ICP) and ICP–mass spectrometry (MS)]. The types of samples included in the study were minced fish, wheat bran, milk powder, bovine and pig liver, mushroom, 2 simulated diets, and bovine muscle; the last 4 were certified reference materials. These were analyzed as single (4 samples), double blind (1 sample), or split level (2 samples) samples. Before the collaborative study, a pretrial was conducted in which 4 ready-made solutions and one fish tissue sample were analyzed for Pb and Cu. The reproducibility relative standard deviation (RSDR) values, for results above the detection limit, ranged from 59% at 0.155 mg/kg to 16% at 1.62 mg/kg for Pb, from 28% at 0.0124 mg/kg to 11% at 0.482 mg/kg for Cd, from 9.3% at 35.3 mg/kg to 1.7% at 147 mg/kg for Zn, from 39% at 0.241 mg/kg to 3.0% at 63.4 mg/kg for Cu, and from 17% at 7.4 mg/kg to 5.9% at 303 mg/kg for Fe. The RSDR values agreed well with the norms described by the International Union of Pure and Applied Chemistry. As a complement to the AAS determinations, a number of laboratories analyzed the samples either by ICP or by ICP–MS. The results of these analyses agreed well with the AAS results. On the basis of the results of the collaborative study, the method was adopted Official First Action by AOAC INTERNATIONAL.
Semi-Automated Direct Epifluorescent Filter Technique for Total Bacterial Count in Raw Milk
Authors: Hermida María , Taboada Margarita , Menéndez Santiago , Rodríguez-Otero José Luis
Published: July 2020

The Direct Epifluorescent Filter Technique (DEFT) and the reference method of counting total bacterial colonies on Petri dishes were compared. IDF Standards 128 (1985) and 161A (1995) were applied. A total of 496 samples of milk were analyzed. Colony forming units per μL milk were transformed to decimal logarithmic units: log (cfu/μL). The repeatability standard deviation, Sr = 0.114, was typical for a routine microbiological method. To study the carryover at different levels of bacteria, 3 tests were performed on milk samples of approximately 100, 700, and >1000 cfu/μL. For the first 2 experiments, no carryover was detected; in the milk sample with >1000 cfu/μL, the carryover was <0.12%. When the DEFT counts were regressed versus the reference method, the values of the slope and intercept were 0.92 and 0.17, respectively; the correlation coefficient was r = 0.84; and the residual standard deviation was Syx = 0.287. The paired t-test showed that the reference method and DEFT do not give significantly different results (p = 0.05).
Determination of Iodine-131 at Low Levels in Milk: Collaborative Study
Authors: Baratta Edmong J , Easterly David G ,   Collaborators:, Bell S A , Cheng C-S , Daly J , Fuhrmann G C , Kapish J B , Kingan K L , Larsen I L , Schlenker J M , Sheibley R H , Silverstone M , Uyesugi G S
Published: July 2020

The official method for the determination of iodine-131 in milk has a lower limit of detection (LLD) of 10 pCi/L (0.37 Bq/L). The Nuclear Regulatory Commission had recommended that a method claiming to have an LLD of <0.3 pCi/L (<1.1E-02 Bq/L) be used. That method, which is capable of measuring iodine-131 below the level of detection of the Official Method, was collaboratively studied. The method uses a palladium iodide precipitate to concentrate the iodine-131 and measures (counts) its 364 keV gamma energy in coincidence with the beta decay or with a low-background beta-counting system. The study was performed by using 3 concentrations of iodine- 131 in milk: 2.6, 5.0, and 8.0 pCi/L (9.62E-02, 1.85E-01, and 2.96E-01 Bq/L, respectively). Eleven laboratories agreed to participate in the study. Eight laboratories submitted data for the study. The averages of the results were 2.68, 5.30, and 8.12 pCi/L (9.92E-02, 1.96E-01, and 3.00E-01 Bq/L, respectively), respectively. The intra- and interlaboratory variations were acceptable. The method was adopted First Action by AOAC INTERNATIONAL.
Investigation of Ketoconazole Copper(II) and Cobalt(II) Complexes and Their Spectrophotometric Applications
Authors: El-Ragehy Nirman A , El-Saharty Yasser S
Published: July 2020

Ketoconazole, as a ligand, reacts quantitatively with copper(II) and cobalt(II) to form blue-colored, stable complexes in dichloromethane. These complexes can be spectrophotometrically measured at 720 and 612.5 nm in the case of Cu(II) or Co(II), respectively. Different factors affecting the reaction such as pH, reagent concentration, solvent effect, and time were studied. By using Job's method of continuous variation, the stoichiometry of the reaction was found to be in the ratio of 1:2, metal:drug, with Cu(II) and Co(II). The stability of the complexes formed was also studied. The reaction products were isolated for further investigation. The complexes have apparent molar absorptivities of 35.36 ± 1.95 and 59.62 ± 1.87 for Cu(II) and Co(II), respectively. Suggested procedures based on the stoichiometric reaction were successfully applied to the analysis of the pure drug and its pharmaceutical formulations. The validity of the procedures was further ascertained by the method of standard additions. The developed method was found to be simple, accurate, and precise when compared with the official method of the British Pharmacopoeia.
Evaluation of VIDAS® Immuno-Concentration Salmonella/VIDAS Salmonella Immunoassay Method for Detection of Salmonella in Selected Foods: Collaborative Study
Authors: Lepper Wendy A , Schultz Ann M , Curiale Michael S , Johnson Ronald L ,   Collaborators:, Agin J , Campbell S , Carver C , Cherney D , Copeland F , Ekholm D , Eklund C , Gangar V , Gardner F , Herbst K , High E , Kallstrom C , Lee J , Lucas J , Lyons W , Maselli M , Miele M , Muehlenkamp E , Muzzy T , Nutsch A , Parra G , Post L , Ryser E , Schultz A , Scorah C , Shebuski J , Shields J , Smith J , Smith M , Stawick B , Trefla J , Vasavada P C , Vought K , Williams J , Witt J , Woodruff T
Published: July 2020

The VIDAS Immuno-concentration Salmonella (ICS)/VIDAS Salmonella (SLM) immunoassay method for the detection of Salmonella was compared to the Bacteriological Analytical Manual (BAM)/AOAC culture method in a collaborative study. Thirty-two laboratories participated in the evaluation. Each laboratory tested one or more of the 6 test products: milk chocolate, nonfat dry milk, dried whole egg, soy flour, ground black pepper, and ground raw turkey. The 2 methods were in agreement for 1266 of the 1440 samples. Of the 174 samples not in agreement, 69 were VIDAS ICS/SLM-positive and BAM/AOAC-negative and 105 were VIDAS ICS/SLM-negative and BAM/AOAC-positive.
Multielement Analysis of Housewares and Other Food-Related Items by a 241Am Radioisotope X-Ray Fluorescence Transportable Spectrometer and Handheld Analyzers
Authors: Anderson David L
Published: July 2020

Radioisotopic X-ray fluorescence spectrometry (RXRFS) performed with an analyzer based on a 241Am excitation source was investigated as a potential field method for screening housewares for the presence of toxic elements. A compact system based on commercially available detection and multichannel analyzer components was used to measure surface concentrations of Au, Ba, Bi, Cd, Ce, Co, Cs, Cu, Fe, La, Pb, Sb, Sn, Sr, Zn, and Zr in a wide variety of housewares and other food-related items. Certified reference material solders, glasses, and paint films and well-characterized oven-fired test tile glazes, solders, and metal can seams were analyzed to determine element sensitivities and analytical limits and to demonstrate the accuracy of the instrument. With analysis times of 3–5 min, the analyzer demonstrated 3σ limits of detection of ≤100 μg/cm2 for elements with Z = 40–65 and Z > 70. Very good accuracy was demonstrated for glaze and thin-sample analyses, whereas analysis was possible for solders and metal can seams with greater uncertainties (20–40%). Two commercially available handheld RXRFS analyzers, evaluated as part of the study, yielded results that agreed well with those obtained with the 241Am-based RXRFS system.
Effectiveness of Universal Pre-enrichment Broth for Recovery of Salmonella from Selected Dairy Foods
Authors: Hammack Thomas S , Amaguaña R Miguel , Johnson Mildred L , Andrews Wallace H
Published: July 2020

The relative efficiencies of 2 Bacteriological Analytical Manual (BAM) pre-enrichments, lactose broth (LAC) and brilliant green water (BGW), were compared with Universal Pre-enrichment (UP) broth for the recovery of individual Salmonella serovars from instant nonfat dry milk (NFDM), dry whole milk (DWM), lactic casein (LC), and liquid whole milk (LWM). BGW was compared with UP broth for the analysis of NFDM and DWM but not with the other 2 matrixes. LAC was compared with UP broth for the analysis of LC and LWM. UP broth was made both from a commercial dehydrated preparation (UPC) and from individual ingredients (UPI). Bulk quantities of the selected dairy foods were inoculated with Salmonella serovars at levels intended to produce fractionally positive results, where at least half of the test portions analyzed, with one of the methods being evaluated, would be shown to be Salmonella-positive. For NFDM, in 6 of 9 experiments, with 2 different Salmonella serovars, BGW was significantly more productive than either UPI or UPC broth (p < 0.05). Salmonella was recovered from 118 of 180 test portions with BGW, from 25 of 180 test portions with UPC, and from 14 of 180 test portions with UPI. For DWM, in 2 of 4 experiments, with 2 different Salmonella serovars, BGW was significantly more productive than either UPI or UPC broth (p < 0.05). Salmonella was recovered from 67 of 80 test portions with BGW, from 36 of 80 test portions with UPC, and from 37 of 80 test portions with UPI. For LWM, in 9 of 9 experiments, with 3 different Salmonella serovars, there were no significant differences among the broths. Salmonella was recovered from 120 of 180 test portions with LAC, from 135 of 180 test portions with UPC, and from 129 of 180 test portions with UPI. For LC, in 5 of 7 experiments, with 2 different Salmonella serovars, both UPI and UPC broth were significantly more productive than LAC (p < 0.05). Salmonella was recovered from 42 of 140 test portions with LAC, from 114 of 140 test portions with UPC, and from 114 of 140 test portions with UPI. In addition, overall results showed that UPC and UPI broths were equivalent for the recovery of Salmonella from the foods tested, without regard to their performance in comparison with either LAC or BGW.
Testing Green Coffee for Ochratoxin A, Part I: Estimation of Variance Components
Authors: Vargas Eugenia A , Whitaker Thomas B , Santos Eliene A , Slate Andrew B , Lima Francisco B , França Regina C A
Published: July 2020

The variability associated with testing lots of green coffee beans for ochratoxin A (OTA) was investigated. Twenty-five lots of green coffee were tested for OTA contamination. The total variance associated with testing green coffee was estimated and partitioned into sampling, sample preparation, and analytical variances. All variances increased with an increase in OTA concentration. Using regression analysis, mathematical expressions were developed to model the relationship between OTA concentration and the total, sampling, sample preparation, and analytical variances. The expressions for these relationships were used to estimate the variance for any sample size, subsample size, and number of analyses for a specific OTA concentration. Testing a lot with 5 μg/kg OTA using a 1 kg sample, Romer RAS mill, 25 g subsamples, and liquid chromatography analysis, the total, sampling, sample preparation, and analytical variances were 10.75 (coefficient of variation [CV] = 65.6%), 7.80 (CV = 55.8%), 2.84 (CV = 33.7%), and 0.11 (CV = 6.6%), respectively. The total variance for sampling, sample preparation, and analytical were 73, 26, and 1%, respectively.
Determination of Multiclass Pesticide Residues in Apple Juice by Gas Chromatography-Mass Selective Detection after Extraction by Matrix Solid-Phase Dispersion
Authors: Hu Xiaozhong , Jianxin Yu , Zhigang Yan , Lansun Ni , Yanfei Lin , Peng Wang , Jing Li , Xin Huang , Xiaogang Chu , Yibin Zhang
Published: July 2020

A multiresidue method is described for the analysis of 106 multiclass pesticides (organochlorine, organophosphate, carbamate, pyrethroid, and triazine classes) in apple juice in a single injection. The determination procedure was based on matrix solid-phase dispersion of juice on diatomaceous earth in a glass column and subsequent extraction with a mixture of hexane–dichloromethane (1 + 1) at a flow rate of 5 mL/min. The analytes were determined by capillary gas chromatography with mass spectrometric detection and confirmed by their retention times and ion ratios. The coefficients of variation for analysis of samples fortified over the range of 0.01–0.2 mg/kg were 1.62 to 18.4%, and the recoveries for all analytes were between 70 and 110%.
Determination of Egg Proteins in Snack Food and Noodles
Authors: Williams Kristina M , Westphal Carmen D , Shriver-Lake Lisa C
Published: July 2020

Egg is one of the 5 major allergenic foods that are responsible for more than 3/4 of food allergies in children. Food-allergic responses can be controlled by avoidance of the offending foods. The applicability of a commercial enzyme-linked immunosorbent assay (ELISA) kit for the detection of egg in food products such as cookies, crackers, pretzels, salad dressings, and raw and cooked noodles was evaluated. A preliminary evaluation of an antibody-based biosensor was also performed. A National Institute of Standards and Technology (NIST) whole dried egg powder reference material, SRM 8415, was used as a standard. A homogeneous and stable aqueous egg suspension was prepared for the evaluation of the performance of the Veratox for Egg Allergen Test (Neogen Corp., Lansing, MI). This test does not detect egg yolk proteins. Each gram of the aqueous dried egg suspension contained 643 μg whole dried egg, 0.5 mg thimerosal, and 2.5 mg bovine serum albumin. When cookies, crackers, salad dressings, noodles, and ice cream were spiked at a level of 24 mg/kg SRM 8415, recoveries for whole egg averaged about 28%. All foods containing egg as indicated on the ingredient label were found positive by the Veratox test. No false positives occurred in samples that did not contain eggs. Similar results were obtained using the Naval Research Laboratory (NRL) array biosensor, an evanescent wave fluoroimmunosensor. Results for cooked noodles showed that they contained <1% of the egg found in uncooked noodles. A comparison of extracts from cooked and uncooked noodles by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) revealed differences in protein profiles. The boiling of the noodles could have reduced the immunoreactivity of the egg proteins to the antibodies used in the kit or rendered the egg proteins nonextractable.
A Double-Line Sequential Injection System for the Spectrophotometric Determination of Copper, Iron, Manganese, and Zinc in Waters
Authors: Morais Inês P A , Souto M Renata S , Rangel António O S S
Published: July 2020

A double-line sequential injection system was developed for the spectrophotometric determination of several metal ions in waters. The proposed double-line configuration was used to enable adding sample and chromogenic reagents as merging zones. The methodology was applied to the spectrophotometric determination of copper, iron, manganese, and zinc in samples of diverse origins at the range of 0.15–5.00, 0.10–10.0, 0.48–4.00, and 0.11–5.00 mg/L, respectively. Different chromogenic reagents and detection wavelengths were used. The chromogenic reagents for iron and manganese were 1,10-phenanthroline and formaldoxime, respectively. Copper and zinc were both determined using the analytical reagent zincon. Analytical characteristics of the methodology, such as manifold parameters, buffer pH, and reagent concentrations were optimized, and interference of some of the metal ions commonly present in water sample was assessed. Results of the analysis were in agreement with those obtained by atomic absorption spectrometry. Repeatability, expressed as the relative standard deviation for 10 consecutive injections of water samples, was lower than 6%. The determination rate was approximately 36/h.
Determination of Methylbenzoquate in Premixes and Animal Feeds Using Liquid Chromatography with Fluorescence Detection
Authors: Douša Michal , Lemr Karel , Stránský Zdeněk
Published: July 2020

A rapid analytical procedure was developed and tested for routine identification and quantification of methylbenzoquate in feeds by liquid chromatography (LC). The ground feed samples were extracted using methanol–water (80 + 20, v/v) at 65°–70°C in a water bath for premixes and in dichloromethane at 45°C in a water bath for final feeds, respectively. The extract of final feeds was cleaned using solid-phase extraction on silica columns. Both the final feed and premix extracts were analyzed by reversed-phase LC on a NovaPak C18 column (3.9 × 150 mm; 4 μm) with methanol-acetonitrile-water-phosphoric acid (340 + 350 + 308 + 2, v/v) as mobile phase. Fluorescence detection was performed at excitation and emission wavelengths of 265 and 390 nm, respectively. Alternatively, post-column addition sulfuric acid solution was used to decrease the determination limit. The recovery of methylbenzoquate, in a concentration range of 0.5–10 mg/kg, was 105.0 ± 7.3%. The limit of quantitation, based on a signal-to-noise ratio of 10:1, was 48 μg/kg. The developed LC method was tested in an interlaboratory study. The interlaboratory repeatibility for both samples ranged from 7.1 to 10.6%; the interlaboratory reproducibility ranged from 11.7 to 15.2%. With the post-column addition of sulfuric acid, the limit of quantification was decreased by a factor of 50. Overall, the developed method is highly selective and can be used in routine analysis.
Determination of Flavonol Aglycones in Ginkgo biloba Dietary Supplement Crude Materials and Finished Products by High-Performance Liquid Chromatography: Single Laboratory Validation
Authors: Gray Dean , Le Vanseler Kerri , Pan Meide
Published: July 2020

A single laboratory validation (SLV) was completed for a method to determine the flavonol aglycones quercetin, kaempferol, and isorhamnetin in Ginkgo biloba products. The method calculates total glycosides based on these aglycones formed following acid hydrolysis. Nine matrixes were chosen for the study, including crude leaf material, standardized dry powder extract, single and multiple entity finished products, and ethanol and glycerol tinctures. For the 9 matrixes evaluated as part of this SLV, the method appeared to be selective and specific, with no observed interferences. The simplified 60 min oven heating hydrolysis procedure was effective for each of the matrixes studied, with no apparent or consistent differences between 60, 75, and 90 min at 90°C. A Youden ruggedness trial testing 7 factors with the potential to affect quantitative results showed that 2 factors (volume hydrolyzed and test sample extraction/hydrolysis weight) were the most important parameters for control during sample preparation. The method performed well in terms of precision, with 4 matrixes tested in triplicate over a 3-day period showing an overall repeatability (relative standard deviation, RSD) of 2.3%. Analysis of variance testing at α = 0.05 showed no significant differences among the within- or between-group sources of variation, although comparisons of within-day (Sw), between-day (Sb), and total (St) precision showed that a majority of the standard deviation came from within-day determinations for all matrixes. Accuracy testing at 2 levels (approximately 30 and 90% of the determined concentrations in standardized dry powder extract) from 2 complex negative control matrixes showed an overall 96% recovery and RSD of 1.0% for the high spike, and 94% recovery and RSD of 2.5% for the low spike. HorRat scores were within the limits for performance acceptability, ranging from 0.4 to 1.3. Based on the performance results presented herein, it is recommended that this method progress to the collaborative laboratory trial.
Single-Laboratory Validation for the Determination of Terpene Lactones in Ginkgo biloba Dietary Supplement Crude Materials and Finished Products by High-Performance Liquid Chromatography with Evaporative Light-Scattering Detection
Authors: Croom Edward , Pace Roberto , Paletti Andrea , Sardone Nicola , Gray Dean
Published: July 2020

A single-laboratory validation was completed for a method to determine total terpene lactones in Ginkgo biloba products. The method determines terpene lactones on the basis of the main terpene lactones (Bilobalide, Ginkgolide A, Ginkgolide B, Ginkgolide C, and Ginkgolide J) by high-performance liquid chromatography with evaporative light-scattering detection after extraction. Nine matrixes were chosen for study, including crude leaf material, standardized dry powder extract, single- and multiple-entity finished products, and alcohol and glycerin tinctures. The sample purification with prepacked columns allows selective extraction of the terpene lactones with no interferences from any matrix under study. A Youden ruggedness trial testing 7 instrumental and preparation factors with the potential to affect quantitative results showed that 2 factors (volume of the column elution solvent and pH of the diluent) were the most important parameters to control during sample preparation. The method performed well in terms of precision; 4 matrixes tested in triplicate over a 3-day period showed an overall repeatability relative standard deviation (RSD) of about 3%. HorRat values were within the limits for performance acceptability, ranging from 0.5 to 1.0. Analysis of variance testing at = 0.05 showed no significant differences among the within-or between-group sources of variation, although comparison of within-day, between-day, and total precision showed that most of the RSD came from within-day determinations except those for the Ginkgo dry extract (Gb-SLV-2). Accuracy testing at 4 concentration levels of terpene lactones obtained by spiking a negative control matrix at approximately 300, 750, 1500, and 2250 g/mL gave recoveries of about 91% for the 300 g/mL level, about 98% for the 750 g/mL level, about 99% for the 1500 g/mL level, and 97% for the 2250 g/mL level with an overall recovery of 96% and an RSD of 3.2%.
Precollaborative Study of the GeneQuence® Salmonella Assay Using 24-Hour Enrichment Protocols for Detection of Salmonella spp. in Select Foods
Authors: Alles Susan , Peng Xuan , Wendorf Michael , Mozola Mark
Published: July 2020

New enrichment protocols are described for use with a DNA hybridization (DNAH) method for detection of Salmonella spp. in select foods. GeneQuence® Salmonella, in its original version, utilized a 3-stage enrichment of minimum 42 h duration. New 2-stage procedures of 2428 h duration are described for raw poultry, raw beef, pasteurized egg products, milk chocolate, and dry pet food. In the validation study described here, a total of 345 samples were tested by the abbreviated DNAH method in parallel with either the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA/BAM) or U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS) reference culture procedures. Results showed an overall sensitivity for the DNAH method of 97.1% (false-negative rate 2.9%). There were no false-positive results by the DNAH method; therefore the specificity was 100%. Overall agreement between the DNAH and reference culture methods was 98.5%. There were no significant differences in performance between the DNAH and reference methods for any of the foods tested as determined by Chi-square analysis. It is recommended that the DNAH method be subjected to AOAC collaborative study.
Simultaneous Liquid Chromatographic Determination of Ezetimibe and Simvastatin in Pharmaceutical Products
Authors: Oliveira Paulo Renato , Barth Thiago , Todeschini Vitor , Dalmora Sérgio luiz
Published: July 2020

A reversed-phase liquid chromatographic (LC) method was developed and validated for the simultaneous determination of ezetimibe and simvastatin in pharmaceutical dosage forms. The LC method was carried out on a Synergi fusion C18 column (150 mm 4.6 mm id) maintained at 45C. The mobile phase consisted of phosphate buffer 0.03 M, pH 4.5acetonitrile (35 + 65, v/v) run at a flow rate of 0.6 mL/min, and detection was made using a photodiode array detector at 234 nm. The chromatographic separation was obtained within 15.0 min, and calibration graphs were linear in the concentration range of 0.5200 g/mL. Validation parameters such as specificity, linearity, precision, accuracy, and robustness were evaluated, giving results within the acceptable range for both compounds. Moreover, the proposed method was successfully applied for the routine quality control analysis of pharmaceutical products.
Event-Specific Qualitative and Quantitative Polymerase Chain Reaction Methods for Detection of Genetically Modified Rapeseed Ms8Rf3 Based on the Right Border Junctions
Authors: Wu Gang , Wu Yuhua , Xiao Ling , Lu Changming
Published: July 2020

Ms8Rf3 is a genetically modified rapeseed hybrid which is widely cultivated in Canada and exported to some other countries for production of foodstuffs or fodder. In this study, the genomic sequences flanking the right borders of the integrated transgenic sequences in the Ms8Rf3 genome were characterized and showed high similarities with the bacterial artificial chromosome clone of Chinese cabbage. Event-specific qualitative polymerase chain reaction (PCR) methods were established with the primers and probes targeting the junction regions to produce a 123 base pair (bp) product for the Ms8 event and 92 bp for the Rf3 event. The absolute detection limit of qualitative PCR was 2.5 initial template copies for the Ms8 event and 50 copies for the Rf3 event. Quantitiative detection methods were established, with the absolute quantification limit being approximately 25 initial template copies.
Comparison of Standard Moisture Loss-on-Drying Methods for the Determination of Moisture Content of Corn Distillers Dried Grains with Solubles
Authors: Ileleji Klein E , Garcia Arnoldo A , Kingsly Ambrose R P , Clementson Clairmont L
Published: July 2020

This study quantified the variability among 14 standard moisture loss-on-drying (gravimetric) methods for determination of the moisture content of corn distillers dried grains with solubles (DDGS). The methods were compared with the Karl Fischer (KF) titration method to determine their percent variation from the KF method. Additionally, the thermo-balance method using a halogen moisture analyzer that is routinely used in fuel ethanol plants was included in the methods investigated. Moisture contents by the loss-on-drying methods were significantly different for DDGS samples from three fuel ethanol plants. The percent deviation of the moisture loss-on-drying methods decreased with decrease in drying temperature and, to a lesser extent, drying time. This was attributed to an overestimation of moisture content in DDGS due to the release of volatiles at high temperatures. Our findings indicate that the various methods that have been used for moisture determination by moisture loss-on-drying will not give identical results and therefore, caution should be exercised when selecting a moisture loss-on-drying method for DDGS.
Evaluation of Different Machines Used to Quantify Genetic Modification by Real-Time PCR
Authors: Allnutt Theodore R , Ayadi Mira , Berben Gilbert , Brodmann Peter , Lee David
Published: July 2020

Quantification of genetic modification (GM) is often undertaken to test for compliance with the European Union GM labeling threshold in food. Different control laboratories will often use common validated methods, but with different models of real-time PCR machines. We performed two separate ring trials to evaluate the relative precision and accuracy of different types of real-time PCR machines used to quantify the concentration of GM maize. Both trials used dual-labeled fluorogenic probes for quantification. The first ring trial used separate GM and reference assays (a single fluorescence channel), and the second used a combined duplex assay (two simultaneous fluorescence channels). Five manufacturers and seven modelsincluding a 96-well microtiter-plate, rotary, and portable machineswere examined. In one trial, the machine used had a significant effect on precision, but in the other it did not. Overall, the degree of variation due to the machine model was lower than other factors. No significant repeatable difference in accuracy was observed between machine models. It was not possible to use sufficient replication of machine type in each laboratory to examine all sources of variation in this study, but the results strongly indicate that factors other than machine type or manufacturer (e.g., method or laboratory) contribute more to variation in a GM quantification result.
108 Impacts of dam age and milk production on cow/calf profitability
Authors: Mulliniks Travis , Beard Joslyn , King Tasha
Published: July 2020

Cow herd profitability can be greatly influenced by reproductive success, average age of herd, and genetic potential within the environment. Productivity is influenced by cow age with calf weaning weight, increasing from 2 to 5 yr of age in dams. With that in mind, increasing average age of the cowherd has the potential to increase cow/calf profitability. Culling cows before 5 yr of age negatively impacts production efficiency due to decreased calf weaning weight in younger cows and subsequently, increase replacement rate and costs. Therefore, reproduction in young cattle is important to overall economic efficiency within the cow herd and a driving factor in longevity. Due to decreased reproduction and offspring performance, young females have previously been considered an economic liability. The effect of increased average cow age within the herd along with increased pregnancy rate of young cows has shown to increase production efficiency by decreasing replacement rates and adding greater production potential with increased calf weaning weights. In young beef cows, partitioning nutrients away from lactational demands allows for nutrients to be utilized for cow growth and reproduction. An increase in selection for milk production has resulted in beef cows undergoing greater nutritional stress during early lactation, which ultimately reduces cowherd reproduction and efficiency. Although a big emphasis is placed on output traits, economic value of reproduction is 5 times greater than growth or maternal output traits in beef cattle. In addition, the value of the added milk production may not fully be captured, due to extensive environments with limited nutrients. Even in environments with greater feed resources, selection for milk production may led to a decrease in reproduction, production efficiency, and cowherd retention rate.
Dispersion, communication, and alignment: an experimental study of the emergence of structure in combinatorial phonology
Authors: Roberts Gareth , Clark Robin
Published: July 2020

Languages exhibit structure at a number of levels, including at the level of phonology, the system of meaningless combinatorial units from which words are constructed. Phonological systems typically exhibit greater dispersion than would be expected by chance. Several theoretical models have been proposed to account for this, and a common theme is that such organization emerges as a result of the competing forces acting on production and perception. Fundamentally, this implies a cultural evolutionary explanation, by which emergent organization is an adaptive response to the pressures of communicative interaction. This process is hard to investigate empirically using natural-language data. We therefore designed an experimental task in which pairs of participants play a communicative game using a novel medium in which varying the position of one’s finger on a trackpad produced different colors. This task allowed us to manipulate the alignment of pressures acting on production and perception. Here we used it to investigate (1) whether above-chance levels of dispersion would emerge in the resulting systems, (2) whether dispersion would correlate with communicative success, and (3) how systems would differ if the pressures acting on perception were misaligned with pressures acting on production (and which would take precedence). We found that above-chance levels of dispersion emerged when pressures were aligned, but that the primary driver of communicative success was the alignment of production and perception pressures rather than dispersion itself. When they were misaligned, participants both found the task harder and (driven by perceptual demands) created systems with lower levels of dispersion.
The Galactic population and properties of young, highly energetic pulsars
Authors: Johnston Simon , Smith D A , Karastergiou A , Kramer M
Published: July 2020

The population of young, non-recycled pulsars with spin-down energies $\dot{E} \gt 10^{35}$ erg s−1 is sampled predominantly at γ-ray and radio wavelengths. A total of 137 such pulsars are known, with partial overlap between the sources detectable in radio and γ-rays. We use a very small set of assumptions in an attempt to test whether the observed pulsar sample can be explained by a single underlying population of neutron stars. For radio emission we assume a canonical conal beam with a fixed emission height of 300 km across all spin periods and a luminosity law which depends on $\dot{E}^{0.25}$. For γ-ray emission we assume the outer-gap model and a luminosity law which depends on $\dot{E}^{0.5}$. We synthesize a population of fast-spinning pulsars with a birth rate of one per 100 yr. We find that this simple model can reproduce most characteristics of the observed population with two caveats. The first is a deficit of γ-ray pulsars at the highest $\dot{E}$ which we surmise to be an observational selection effect due to the difficulties of finding γ-ray pulsars in the presence of glitches without prior knowledge from radio frequencies. The second is a deficit of radio pulsars with interpulse emission, which may be related to radio emission physics. We discuss the implications of these findings.
New luminous blue variable candidates in the NGC 247 galaxy
Authors: Solovyeva Y , Vinokurov A , Sarkisyan A , Atapin K , Fabrika S , Valeev A F , Kniazev A , Sholukhova O , Maslennikova O
Published: July 2020

We search for luminous blue variable (LBV) stars in galaxies outside the Local Group. Here we present a study of two bright Hα sources in the NGC 247 galaxy. Object j004703.27–204708.4 (MV = −9.08 ± 0.15 mag) shows the spectral lines typical for well-studied LBV stars: broad and bright emission lines of hydrogen and helium He i with P Cyg profiles, emission lines of iron Fe ii, silicon Si ii, nitrogen N ii and carbon C ii, forbidden iron [Fe ii] and nitrogen [N ii] lines. The variability of the object is ΔB = 0.74 ± 0.09 mag and ΔV = 0.88 ± 0.09 mag, which makes it a reliable LBV candidate. The star j004702.18–204739.93 (MV = −9.66 ± 0.23 mag) shows many emission lines of iron Fe ii, forbidden iron lines [Fe ii], bright hydrogen lines with broad wings, and also forbidden lines of oxygen [O i] and calcium [Ca ii] formed in the circumstellar matter. The study of the light curve of this star did not reveal significant variations in brightness (ΔV = 0.29 ± 0.09 mag). We obtained estimates of interstellar absorption, the photosphere temperature, as well as bolometric magnitudes $M_\text{bol}=-10.5^{+0.5}_{-0.4}$ and $M_\text{bol}=-10.8^{+0.5}_{-0.6}$, which correspond to bolometric luminosities $\log (L_\text{bol}/{\rm L}_{\odot })=6.11^{+0.20}_{-0.16}$ and $6.24^{+0.20}_{-0.25}$ for j004703.27–204708.4 and j004702.18–204739.93, respectively. Thus, the object j004703.27–204708.4 remains a reliable LBV candidate, while the object j004702.18–204739.93 can be classified as a B[e]-supergiant.
A chromosome map to unveil stellar populations with different magnesium abundances. The case of ω Centauri
Authors: Milone A P , Marino A F , Renzini A , Li C , Jang S , Lagioia E P , Tailo M , Cordoni G , Carlos M , Dondoglio E
Published: July 2020

Historically, photometry has been largely used to identify stellar populations [multiple populations (MPs)] in globular clusters (GCs) by using diagrams that are based on colours and magnitudes that are mostly sensitive to stars with different metallicities or different abundances of helium, carbon, nitrogen, and oxygen. In particular, the pseudo-two-colour diagram called chromosome map (ChM), allowed the identification and the characterization of MPs in about 70 GCs by using appropriate filters of the Hubble Space Telescope (HST) that are sensitive to the stellar content of He, C, N, O, and Fe.

We use here high precision HST photometry from F275W, F280N, F343N, F373N, and F814W images of ω Centauri to investigate its MPs. We introduce a new ChM whose abscissa and ordinate are mostly sensitive to stellar populations with different magnesium and nitrogen, respectively, in monometallic GCs. This ChM is effective in disentangling the MPs based on their Mg chemical abundances, allowing us to explore, for the first time, possible relations between the production of these elemental species for large samples of stars in GCs.

By comparing the colours of the distinct stellar populations with the colours obtained from appropriate synthetic spectra we provide ‘photometric-like’ estimates of the chemical composition of each population. Our results show that, in addition to first-generation (1G) stars, the metal-poor population of ω Cen hosts four groups of second-generation stars with different [N/Fe], namely, 2GA–D. 2GA stars share nearly the same [Mg/Fe] as the 1G, whereas 2GB, 2GC, and 2GD are Mg depleted by ∼0.15, ∼0.25, and ∼0.45 dex, respectively. We provide evidence that the metal-intermediate populations host stars with depleted [Mg/Fe].
Constraining early-time dust formation in core-collapse supernovae
Authors: Priestley F D , Bevan A , Barlow M J , De Looze I
Published: July 2020

There is currently a severe discrepancy between theoretical models of dust formation in core-collapse supernovae (CCSNe), which predict $\gtrsim 0.01 \, {\rm M}_\odot$ of ejecta dust forming within ∼1000 d, and observations at these epochs, which infer much lower masses. We demonstrate that, in the optically thin case, these low dust masses are robust despite significant observational and model uncertainties. For a sample of 11 well-observed CCSNe, no plausible model reaches carbon dust masses above $10^{-4} \, {\rm M}_\odot$, or silicate masses above $\sim 10^{-3} \, {\rm M}_\odot$. Optically thick models can accommodate larger dust masses, but the dust must be clumped and have a low (<0.1) covering fraction to avoid conflict with data at optical wavelengths. These values are insufficient to reproduce the observed infrared fluxes, and the required covering fraction varies not only between SNe but between epochs for the same object. The difficulty in reconciling large dust masses with early-time observations of CCSNe, combined with well-established detections of comparably large dust masses in supernova remnants, suggests that a mechanism for late-time dust formation is necessary.
Formation of counter-rotating stars during gas-rich disc–disc mergers
Authors: Martel Hugo , Richard Simon
Published: July 2020

We present a new scenario for the origin of the counter-rotating stars in disc galaxies, defined as stars that have a negative tangential velocity. This scenario involves a merger between two gas-rich disc galaxies that have comparable masses, are nearly coplanar, and are rotating in the same direction. The merger results in an intense starburst, during which a significant fraction of the gas is converted to stars. The system then settles into an equilibrium configuration consisting of a thick disc and a bulge partly supported by velocity dispersion and a thin disc supported by rotation. Star formation proceeds until most of the gas supply is exhausted. Stars formed during the starburst have tangential velocities ranging from $-600$ to $600\, {\rm km\, s^{-1}}$. Stars formed afterward in the thick disc and bulge have high eccentricities and low tangential velocities, typically in the range $-100$ to $100\, {\rm km\, s^{-1}}$, while stars formed in the thin disc have large, positive velocities. All fast, counter-rotating stars ($V\lt -200\, {\rm km\, s^{-1}}$) are old, metal-poor, with very low dispersion in ages and metallicities. By contrast, fast, corotating stars ($V\gt 200\, {\rm km\, s^{-1}}$) have a wide range of ages and metallicities. The average abundances ratios $\rm [O/H]$ and [Fe/H] for fast, corotating stars typically exceed the corresponding ratios for fast, counter-rotating stars by $0.1-0.4\,\mathrm{ dex}$, while the dispersion in the values of NFe/NH are larger by factors between 2 and 14. This provides an observational signature of major, gas-rich mergers at high redshift.
Extinct radio pulsars as a source of subrelativistic positrons
Authors: Istomin Ya N , Chernyshov D O , Sob’yanin D N
Published: July 2020

Extinct radio pulsars, in which stationary, self-sustaining generation of a relativistic electron–positron plasma becomes impossible when rotation brakes down, can be sources of a subrelativistic flux of positrons and electrons. We assume that the observed excess of positrons in the bulge and the disc of the Galaxy is associated with these old neutron stars. The production of pairs in their magnetospheres occurs due to one-photon absorption of gamma quanta of the Galactic and extragalactic backgrounds. The cascade process of plasma production leads to the flux of positrons escaping from the open magnetosphere ≃3 × 1034 s−1. The total flux of positrons from all old Galactic neutron stars with rotational periods 1.5 < P < 35 s is ≃3 × 1043 s−1. The energy of positrons is less than ≃10 MeV. The estimated characteristics satisfy the requirements for the positron source responsible for the 511-keV Galactic annihilation line.