bluuebunny/crossref_metadata_2025 huggingface dataset:
Simultaneous Determination of Atorvastatin Calcium and Ramipril in Capsule Dosage Forms by High-Performance Liquid Chromatography and High-Performance Thin Layer Chromatography
Authors: Panchal Hiral J , Suhagia Bhanubhai N
Published: February 2020

Two simple and accurate methods to determine atorvastatin calcium and ramipril in capsule dosage forms were developed and validated using HPLC and HPTLC. The HPLC separation was achieved on a Phenomenex Luna C18 column (250 ⨯ 4.6 mm id, 5 µm) in the isocratic mode using 0.1% phosphoric acidacetonitrile (38 + 62, v/v), pH 3.5 ± 0.05, mobile phase at a flow rate of 1 mL/min. The retention times were 6.42 and 2.86 min for atorvastatin calcium and ramipril, respectively. Quantification was achieved with a photodiode array detector set at 210 nm over the concentration range of 0.5-5 µg/mL for each, with mean recoveries (at three concentration levels) of 100.06 ± 0.49% and 99.95 ± 0.63% RSD for atorvastatin calcium and ramipril, respectively. The HPTLC separation was achieved on silica gel 60 F254 HPTLC plates using methanolbenzeneglacial acetic acid (19.6 + 80.0 + 0.4, v/v/v) as the mobile phase. The Rf values were 0.40 and 0.20 for atorvastatin calcium and ramipril, respectively. Quantification was achieved with UV densitometry at 210 nm over the concentration range of 50500 ng/spot for each, with mean recoveries (at three concentration levels) of 99.98 ± 0.75% and 99.87 ± 0.83% RSD for atorvastatin calcium and ramipril, respectively. Both methods were validated according to International Conference on Harmonization guidelines and found to be simple, specific, accurate, precise, and robust. The mean assay percentages for atorvastatin calcium and ramipril were 99.90 and 99.55% for HPLC and 99.91 and 99.47% for HPTLC, respectively. The methods were successfully applied for the determination of atorvastatin calcium and ramipril in capsule dosage forms without any interference from common excipients.
Determination of Calcium, Magnesium, Sodium, and Potassium in Foodstuffs by Using a Microsampling Flame Atomic Absorption Spectrometric Method After Closed-Vessel Microwave Digestion: Method Validation
Authors: Chekri Rachida , Noël Laurent , Vastel Christelle , Millour Sandrine , Kadar Ali , GuÉrin Thierry
Published: February 2020

This paper describes a validation process in compliance with the NF/EN ISO/IEC 17025 standard for the determination of the macrominerals calcium, magnesium, sodium, and potassium in foodstuffs by microsampling with flame atomic absorption spectrometry after closed-vessel microwave digestion. The French Standards Commission (Agence Francaise de Normalisation) standards NF V03-110, NF EN V03-115, and XP T-90-210 were used to evaluate this method. The method was validated in the context of an analysis of the 1322 food samples of the second French Total Diet Study (TDS). Several performance criteria (linearity, LOQ, specificity, trueness, precision under repeatability conditions, and intermediate precision reproducibility) were evaluated. Furthermore, the method was monitored by several internal quality controls. The LOQ values obtained (25, 5, 8.3, and 8.3 mg/kg for Ca, Mg, Na, and K, respectively) were in compliance with the needs of the TDS. The method provided accurate results as demonstrated by a repeatability CV (CVr) of <7 and a reproducibility CV (CVR) of <12 for all the elements. Therefore, the results indicated that this method could be used in the laboratory for the routine determination of these four elements in foodstuffs with acceptable analytical performance.
Genotyping of Francisella tularensis, the Causative Agent of Tularemia
Authors: Johansson Anders , Petersen Jeannine M
Published: February 2020

Francisella tularensis is a facultative, intracellular, zoonotic pathogen and the causative agent of tularemia. Historically, F. tularensis has been subdivided into subspecies on the basis of phenotypic traits, including biochemical reactivity and virulence. More recently, a number of genotypic methods, ranging from relatively insensitive methods to full genome sequencing, have been used to investigate genetic diversity within F. tularensis. These analyses indicate that F. tularensis is a pathogen of low sequence diversity with pair-wise average nucleotide identities >99.2 across subspecies. Nonetheless, genomic rearrangements and sequence deletions exist between and within F. tularensis subspecies, creating polymorphisms detectable by genotyping methods. Genetic subpopulations intermediate to the subspecies and strain level have been identified within F. tularensis subsp. tularensis and F. tularensis subsp. holarctica by several different typing methods. These genetic subpopulations have been associated with differences in disease severity, geographic distribution, and transmission patterns. For example, one F. tularensis subsp. tularensis subpopulation has been found to be significantly associated with mortality in humans. Additionally, genotypic analyses of Francisella spp. have provided information for use in the rational design of strain panels for validation of F. tularensis diagnostic tests. This review provides a guide to the various F. tularensis genotyping methods.
Analysis of Acrylonitrile, 1,3-Butadiene, and Related Compounds in Acrylonitrile-Butadiene-Styrene Copolymers for Kitchen Utensils and Children's Toys by Headspace Gas Chromatography/Mass Spectrometry
Authors: Ohno Hiroyuki , Kawamura Yoko
Published: February 2020

A headspace gas chromatography/mass spectrometry method was developed for the simultaneous determination of the residual levels of acrylonitrile (AN), 1,3-butadiene (1,3-BD), and their related compounds containing propionitrile (PN) and 4-vinyl-1-cyclohexene (4-VC) in acrylonitrilebutadiene-styrene (ABS) copolymers for kitchen utensils and children's toys. A sample was cut into small pieces, then N,N-dimethylacetamide and an internal standard were added in a sealed headspace vial. The vial was incubated for 1 h at 90C and the headspace gas was analyzed by gas chromatography/mass spectrometry. The recovery rates of the analytes were 93.3101.8 and the coefficients of variation were 0.36.5. In ABS copolymers, the levels were 0.350.4 g/g for AN, ND4.5 g/g for PN, 0.061.58 g/g for 1,3-BD, and 1.1295 g/g for 4-VC. The highest level was found for 4-VC, which is a dimer of 1,3-BD, and the next highest was for AN, which is one of the monomers of the ABS copolymer. Furthermore, the method was also applied to acrylonitrile-styrene (AS) copolymers and polystyrenes (PS) for kitchen utensils, and nitrile-butadiene rubber (NBR) gloves. In AS copolymers, AN and PN were detected at 16.854.5 and 0.86.9 g/g, respectively. On the other hand, the levels in PS and NBR samples were all low.
RP-HPLC Method for Simultaneous Determination of Butenafine Hydrochloride and Betamethasone Dipropionate in a Cream Formulation
Authors: Bhosale Suryakant D , Rajput Sadhana J
Published: February 2020

An RP-HPLC method has been developed for the simultaneous determination of butenafine hydrochloride and betamethasone dipropionate on an Inertsil C18 column (250×4.6 mm id) using a mobile phase gradient consisting of methanol and water at a flow rate of 1 mL/min. Detection was carried out at 254 nm. Retention times of betamethasone dipropionate and butenafine hydrochloride were 4.82 (±0.80) and 16.18 (±0.17) min, respectively. The method was validated with respect to specificity, linearity, accuracy, precision, ruggedness, and robustness. This method is simple, precise, and sensitive, and applicable for the simultaneous quantification of butenafine hydrochloride and betamethasone dipropionate in a cream formulation.
Determination of Arsenic in Scalp Hair Samples from Exposed Subjects Using Microwave-Assisted Digestion With and Without Enrichment Based on Cloud Point Extraction by Electrothermal Atomic Absorption Spectrometry
Authors: Kazi Tasneem Gul , Baig Jameel Ahmad , Shah Abdul Qadir , Kandhro Ghulam Abbas , Khan Sumaira , Afridi Hassan Imran , Kolachi Nida Fatima , Wadhwa Sham Kumar , Shah Faheem , Baig Akhtar Mehmood
Published: February 2020

A simple and rapid cloud point extraction (CPE) procedure was applied for preconcentration of trace quantities of arsenic (As) in scalp hair samples. The samples were subjected to microwave-assisted digestion in a mixture of nitric acid and hydrogen peroxide (2 + 1, v/v) prior to preconcentration by CPE. The As in digested samples was complexed with ammonium pyrrolidine dithiocarbamate (APDC), and the resultant As-PDC complex was extracted by a nonionic surfactant, octylphenoxypolyethoxyethanol (Triton X-114). After centrifugation, the surfactant-rich phase was diluted with 0.1 M HNO3 in methanol and analyzed by electrothermal atomic absorption spectrometry. The experimental parameters, i.e., amount of APDC, concentration of Triton X-114, equilibrium temperature and time, were optimized. For validation of the proposed method, a certified reference material (CRM) of human hair (BCR 397) was used. No significant difference (P>0.05) was observed between the experimental results and certified values of the CRM (paired t-test). The LOD and LOQ obtained under the optimal conditions were 0.025 and 0.083 μg/kg, respectively. The developed method was applied for the determination of As in scalp hair samples from male and female subjects of two villages of Khairpur Mir's, Pakistan.
Resolution and Quantification of Isomeric Fatty Acids by Silver Ion HPLC: Fatty Acid Composition of Aniseed Oil (Pimpinella anisum, Apiaceae)
Authors: Denev Roumen V , Kuzmanova Ivalina S , Momchilova Svetlana M , Nikolova-Damyanova Boryana M
Published: February 2020

A silver ion HPLC procedure is described that is suitable to determine the fatty acid composition of plant seed oils. After conversion of fatty acids to p-methoxyphenacyl derivatives, it was possible to achieve baseline resolution of all fatty acid components with 0 to 3 double bonds, including the positionally isomeric 18:1 fatty acids oleic acid (cis 9-18:1), petroselinic acid (cis 6-18:1), and cis-vaccenic acid (cis 11-18:1), in aniseed oil (Pimpinella anisum, Apiaceae) by a single gradient run on a single cation exchange column laboratory converted to the silver ion form. The UV detector response (280 nm) was linearly related to the fatty acid concentration in the range 0.01 to 3.5 mg/mL.
European Analytical Criteria: Past, Present, and Future
Authors: Vanhaecke Lynn , Gowik Petra , Bizec Bruno Le , Ginkel Leen Van , Bichon Emmanuelle , Blokland Marco , Brabander Hubert F De
Published: February 2020

In this paper, the past, present, and (possible) future of the European analytical criteria for residues are described. The elaboration of the revision of Commission Decision 93/256/EC was a long process starting in 1996 and ending with the formation of a European Commission (EC) working group in 1998. This working group took account of developments in scientific and technical knowledge at that time and produced a draft version of the revision within 6 months. The revision, finally published in 2002 (2002/657/EC), includes new ideas on the identification of analytes and the criteria for performance assessment as well as validation procedures. Currently (2009), the evolution in analytical equipment and progress in scientific research, accompanied by recent European regulatory changes, demands an update or revision of the 2002/657/EC.
Validation of the Charm MRL-3 for Fast Screening of -Lactam Antibiotics in Raw Milk
Authors: Reybroeck Wim , Ooghe Sigrid , Brabander Hubert F De , Daeseleire Els
Published: February 2020

The biochemicals utilized in the Charm MRL -Lactam test (8 min test) were applied to faster flowing lateral components to create a new 3 min, one-step -lactam test called Charm MRL-3 (Charm Sciences Inc., Lawrence, MA). This new test was validated at T&V-ILVO according to Commission Decision 2002/657/EC. The following analytical parameters were checked: test specificity, detection capability, and test robustness (impact of deviation of the test protocol, and impact of the milk composition, batch differences of reagents). Further, the suitability of the Charm MRL-3 to screen heat-treated milk or milk from animal species other than the cow was also tested. Finally, the test was integrated in the monitoring of dairy samples to check the occurrence of false-negative or false-positive results, and the test was also included in a national ring trial and an international proficiency study. The results proved that the Charm MRL-3 is a fast, simple, and reliable cows' milk test that can be used at the farm level in order to prevent tanker milk contamination, or at the entrance of the dairy plant to screen tanker milk for the presence of -lactam antibiotics.
Chemometric Methods for the Simultaneous Determination of Some Water-Soluble Vitamins
Authors: Mohamed Abdel-Maaboud I , Mohamed Horria A , Mohamed Niveen A , El-Zahery Marwa R
Published: February 2020

Two spectrophotometric methods, derivative and multivariate methods, were applied for the determination of binary, ternary, and quaternary mixtures of the water-soluble vitamins thiamine HCl (I), pyridoxine HCl (II), riboflavin (III), and cyanocobalamin (IV). The first method is divided into first derivative and first derivative of ratio spectra methods, and the second into classical least squares and principal components regression methods. Both methods are based on spectrophotometric measurements of the studied vitamins in 0.1 M HCl solution in the range of 200500 nm for all components. The linear calibration curves were obtained from 2.590 g/mL, and the correlation coefficients ranged from 0.9991 to 0.9999. These methods were applied for the analysis of the following mixtures: (I) and (II); (I), (II), and (III); (I), (II), and (IV); and (I), (II), (III), and (IV). The described methods were successfully applied for the determination of vitamin combinations in synthetic mixtures and dosage forms from different manufacturers. The recovery ranged from 96.1 1.2 to 101.2 1.0 for derivative methods and 97.0 0.5 to 101.9 1.3 for multivariate methods. The results of the developed methods were compared with those of reported methods, and gave good accuracy and precision.
Validation of a Capillary Electrophoresis Method for the Simultaneous Determination of Amlodipine Besylate and Valsartan in Pharmaceuticals and Human Plasma
Authors: Alnajjar Ahmed O
Published: February 2020

A rapid, simple, and sensitive capillary electrophoresis (CE) method was developed and validated for the simultaneous determination of amlodipine (AML) and valsartan (VAL) in pharmaceuticals and human plasma using a UV photodiode array detector. Electrophoretic conditions were optimized to improve separation, sensitivity, and rapidity. The optimal conditions were 25 mM phosphate buffer at pH 8.0, injection time 10.0 s, voltage 25 kV, and column temperature 25C, with detection at 214 nm. The method was found to be linear in the range of 1.035 and 1.0350 mg/L, with weighted regression 0.9999 and 0.9994, for AML and VAL, respectively. Validation of the method showed acceptable intraday and interday accuracy (85.595.3) and precision (RSD 1.644.2) in pharmaceutical formulation and human plasma analysis. The sensitivity of the method was enhanced by both optimization of the CE procedure and preconcentration performed by liquidliquid extraction. The LOD for both AML and VAL was 0.03 mg/L, which allows analysis at the level of the drugs possibly found in human plasma. Therefore, the proposed method is suitable for QC in pharmaceutical laboratories and therapeutic drug monitoring in clinical laboratories.
Aqueous Sulfuric Acid as the Mobile Phase in Cation Ion Chromatography for Determination of Histamine, Putrescine, and Cadaverine in Fish Samples
Authors: Liao Benjamin S , Sram Jackie , Cain Teresa T , Halcrow Kenneth R
Published: February 2020

Aqueous sulfuric acid can be used as the mobile phase in cation ion chromatography to separate the three biogenic amines, putrescine, cadaverine, and histamine, from fish. Various concentrations of aqueous sulfuric acid were investigated to optimize the separation of these three biogenic amines. Aqueous sulfuric acid (5.0 mM) was found to be optimum for the separation and was used to determine the three biogenic amines in fish. The LOQ, defined as the lowest level of the standard calibration curve, was 0.055 ppm (equivalent to 0.55 g/g sample) for putrescine, 0.05 ppm (equivalent to 0.5 g/g sample) for cadaverine, and 1.0 ppm (equivalent to 10 g/g sample) for histamine. From statistical analysis of the LOQ, the method detection limit was 0.003 ppm for putrescine, 0.009 ppm for cadaverine, and 0.16 ppm for histamine. For sample preparation, the fish was composited, homogenized in methanolwater (75 25, v/v), incubated for 15 min at 60C, and centrifuged. The sample solution was micron-filtered before injection. The mobile phase flow rate was 0.8 mL/min under isocratic conditions at room temperature (1525C). The three biogenic amines were separated in the order of increasing retention time, i.e., putrescine, cadaverine, and histamine, within 30 min. The chromatograms showed complete peak separation of the three amines regardless of the difference in fish matrixes.
Determination of Neomycin and Oxytetracycline in the Presence of Their Impurities in Veterinary Dosage Forms by High-Performance Liquid Chromatography/Tandem Mass Spectrometry
Authors: Vučičevič-Prčetič Katarina , Cservenák Robert , Radulović Niko
Published: February 2020

Two HPLC/MS/MS methods, one for determination of neomycin sulfate and the other for determination of oxytetracycline hydrochloride in the presence of their impurities, were developed and validated. Separations were achieved with gradient elution on a C18 column. All components were ionized by positive-ion electrospray and detected by multiple reaction monitoring. Calibration curves were linear, with correlation coefficients >0.99. Precision of the methods was confirmed by RSD values of 0.34 and 0.71% for neomycin and oxytetracycline, respectively. Recovery values of 101.5 and 101.0%, respectively, indicated adequate accuracy. Analysis time for neomycin was 24 min, with the retention time of the main compound at 10.1 min; for oxytetracycline, the analysis time was 18 min, with the main peak at 9.95 min. Longer retention times than expected were a consequence of the necessity of chromatographic separation of isomers with the same ion transition. All impurities defined in the pharmacopoeias were determined and their identities confirmed. The methods were tested for QC of veterinary dosage forms (commercial powders and injections containing these antibiotics).
Development of Quality Assessment Method for Optically Active Food Flavor Chemicals
Authors: Saito Koichi , Hosono Kouhei , Kitazawa Nariko , Iwasaki Yusuke , Ito Rie , Nakazawa Hiroyuki
Published: February 2020

A quality assessment method for commercially available, optically active flavor compounds, namely, menthol, menthyl acetate, borneol, perillaldehyde, and 1,8-cineol, was developed. A gas chromatograph equipped with a flame ionization detector and a DB-5ms capillary column was used for the chemical purity test. A GC/MS with a β-DEX cyclodextrin column was used for the optical purity test, by which the enantiomeric separation of each flavor compound was achieved. Enantiomeric excess was calculated as an expression of optical purity. Of the 25 standard samples subjected to the chemical purity test, six were found to have lower purity than the data provided by the manufacturers. When the same samples were subjected to the optical purity test, 11 were found to have lower purity than that indicated on the reagent labels. These results suggest that there is a need to conduct an optical purity test, in addition to a chemical purity test, for the quality assessment of flavor standards.
Analysis of Pesticides Residues in Fresh Produce Using Buffered Acetonitrile Extraction and Aminopropyl Cleanup with Gas Chromatography/Triple Quadrupole Mass Spectrometry, Liquid Chromatography/Triple Quadrupole Mass Spectrometry, Gas Chromatography/Ion Trap Detector Mass Spectrometry, and GC with a Halogen-Specific Detector
Authors: Brown Amy N , Cook Jo Marie , Hammack Walter T , Stepp Jason S , Pelt Jonathan V , Gerard Ghislain
Published: February 2020

A rapid and inexpensive multiresidue method for determining pesticides in fruits and vegetables is presented. Extraction of a 15 g sample with 15 mL acetonitrile was followed by buffering with magnesium sulfate, sodium chloride, sodium citrate dihydrate, and disodium citrate. Acidification with formic acid prior to dispersive cleanup with aminopropyl sorbent and magnesium sulfate was used to stabilize base-sensitive pesticides such as chlorothalonil. Extracts were concentrated to 2 g/mL. Analyses were conducted by GC/ion trap detector MS, GC-halogen-specific detector, and LC/triple quadrupole MS. Accuracy and repeatability for 166 compounds in tomato, potato, and cabbage were 70–120% and <20% CV in 85% of the compounds, respectively. Reproducibility over a 4 month period in multiple commodities and analytical conditions was 62–124%, with CVs better than 30% for 91% of the compounds. Supply cost/sample was reduced 66%, and time to extract a batch of 24 samples was reduced by half compared to the prior method that used a 50 g sample, 100 mL acetonitrile, multiple SPE columns, and additional instrumentation. Additional extraction studies were conducted in tomatoes, oranges, and green beans at 4 g/mL using a GC/MS triple quadrupole system with a programmable temperature vaporization inlet. Recoveries of 70–120% were achieved in 93% of all compounds in green beans, 95% in tomatoes, and 97% in oranges.
Application of a Liquid Chromatography Tandem Mass Spectrometry Method for the Simultaneous Detection of Seven Allergenic Foods in Flour and Bread and Comparison of the Method with Commercially Available ELISA Test Kits
Authors: Heick Julia , Fischer Markus , Kerbach Sandra , Tamm Ulrike , Popping Bert
Published: February 2020

To protect the allergic consumer, analytical methods need to be capable of detecting allergens in fnished products that typically contain multiple allergens. An LC/MS/MS method for simultaneous detection of seven allergens was developed and compared with commercially available ELISA kits. The detection capabilities of this novel method were demonstrated by analyzing incurred material containing milk, egg, soy, peanut, hazelnut, walnut, and almond. Bread was chosen as a model matrix. To assess the inﬂuence of baking on the method’s performance, analysis was done before and after baking. The same samples were analyzed with ELISA test kits from ELISA Systems, Morinaga, Neogen, and r-Biopharm. Peanut, hazelnut, walnut, and almond could be detected with both ELISA and LC/MS/MS regardless of whether the product was baked or not. LC/MS/MS clearly showed superior detection of milk in processed matrixes compared to ELISA, which exhibited signifcantly lower sensitivities when analyzing the baked products. Similar results were obtained when analyzing egg; however, one kit was capable of detecting egg in the processed samples as well.
Simultaneous Spectrophotometric Kinetic Determination of Four Flavor Enhancers in Foods with the Aid of Chemometrics
Authors: Ni Yongnian , Chen Jinfeng , Kokot Serge
Published: February 2020

A sensitive kinetic spectrophotometric method was developed for the determination of four ﬂavor enhancers—maltol, ethyl maltol, vanillin, and ethyl vanillin—in food samples. The method was based on the reduction of iron(III) by the four analytes in a sulfuric acid medium (0.012 mol/L), and the subsequent interaction of iron(II) with hexacyanoferrate(III) to form the strongly colored Prussian blue complex, which exhibited an absorption maximum at 800 nm. The optimized method had linear calibrations over the concentration ranges of 0.2–2.8 mg/L for maltol, ethyl maltol, and vanillin, as well as 0.2–1.8 mg/L for ethyl vanillin; the corresponding detection limits were 0.07, 0.07, 0.06, and 0.06 mg/L, respectively. Calibration models were constructed from the original and frst-derivative spectral data with the use of partial least-squares (PLS) and principal component regression chemometrics methods. Ultimately, the proposed analytical procedure was successively applied for the determination of the four compounds in commercial food samples with the use of a PLS calibration based on the frst-derivative spectral data. The results were comparable with those from a reference HPLC method.
Development and Application of a Validated Stability-Indicating High-Performance Liquid Chromatographic Method Using Photodiode Array Detection for Simultaneous Determination of Granisetron, Methylparaben, Propylparaben, Sodium Benzoate, and Their Main Degradation Products in Oral
Pharmaceutical Preparations
Authors: Hewala Ismail , El-Fatatry Hamed , Emam Ehab , Mabrouk Mokhtar
Published: February 2020

A simple, rapid, and sensitive RP-HPLC method using photodiode array detection was developed and validated for the simultaneous determination of granisetron hydrochloride, 1-methyl-1H-indazole-3-carboxylic acid (the main degradation product of granisetron), sodium benzoate, methylparaben, propylparaben, and 4-hydroxybenzoic acid (the main degradation product of parabens) in granisetron oral drops and solutions. The separation of the compounds was achieved within 8 min on a SymmetryShield RP18 column (100 × 4.6 mm id, 3.5 μm particle size) using the mobile phase acetonitrile—0.05 M KH2PO4 buffered to pH 3 using H3PO4 (3+7, v/v). The photodiode array detector was used to test the purity of the peaks, and the chromatograms were extracted at 240 nm. The method was validated, and validation acceptance criteria were met in all cases. The robust method was successfully applied to the determination of granisetron and preservatives, as well as their degradation products in different batches of granisetron oral drops and solutions. The method proved to be sensitive for determination down to 0.04% (w/w) of granisetron degradation product relative to granisetron and 0.03% (w/w) 4-hydroxybenzoic acid relative to total parabens.
Pliocene–Early Pleistocene Geological Events Structure Pacific Martens (Martes caurina)
Authors: Schwartz Michael K , Walters Ashley D , Pilgrim Kristine L , Moriarty Katie M , Slauson Keith M , Zielinski William J , Aubry Keith B , Sacks Benjamin N , Zarn Katherine E , Quinn Cate B , Young Michael K
Published: February 2020

The complex topography, climate, and geological history of Western North America have shaped contemporary patterns of biodiversity and species distributions in the region. Pacific martens (Martes caurina) are distributed along the northern Pacific Coast of North America with disjunct populations found throughout the Northwestern Forested Mountains and Marine West Coast Forest ecoregions of the West Coast. Martes in this region have been classified into subspecies; however, the subspecific designation has been extensively debated. In this study, we use genomic data to delineate conservation units of Pacific marten in the Sierra-Cascade-Coastal montane belt in the western United States. We analyzed the mitochondrial genome for 94 individuals to evaluate the spatial distribution and divergence times of major lineages. We further genotyped 401 individuals at 13 microsatellite loci to investigate major patterns of population structure. Both nuclear and mitochondrial DNA suggest substantial genetic substructure concordant with historical subspecies designations. Our results revealed that the region contains 2 distinct mitochondrial lineages: a Cascades/Sierra lineage that diverged from the Cascades/coastal lineage 2.23 (1.48–3.14 mya), consistent with orogeny of the Cascade Mountain chain. Interestingly, Pacific Martes share phylogeographic patterns similar with other sympatric taxa, suggesting that the complex geological history has shaped the biota of this region. The information is critical for conservation and management efforts, and further investigation of adaptive diversity is warranted following appropriate revision of conservation management designations.
Dynamics of the localization of the plastid terminal oxidase inside the chloroplast
Authors: Bolte Susanne , Marcon Elodie , Jaunario Mélanie , Moyet Lucas , Paternostre Maité , Kuntz Marcel , Krieger-Liszkay Anja
Published: February 2020

The plastid terminal oxidase (PTOX) is a plastohydroquinone:oxygen oxidoreductase that shares structural similarities with alternative oxidases (AOXs). Multiple roles have been attributed to PTOX, such as involvement in carotene desaturation, a safety valve function, participation in the processes of chlororespiration, and setting the redox poise for cyclic electron transport. PTOX activity has been previously shown to depend on its localization at the thylakoid membrane. Here we investigate the dynamics of PTOX localization dependent on the proton motive force. Infiltrating illuminated leaves with uncouplers led to a partial dissociation of PTOX from the thylakoid membrane. In vitro reconstitution experiments showed that the attachment of purified recombinant maltose-binding protein (MBP)–OsPTOX to liposomes and isolated thylakoid membranes was strongest at slightly alkaline pH values in the presence of lower millimolar concentrations of KCl or MgCl2. In Arabidopsis thaliana overexpressing green fluorescent protein (GFP)–PTOX, confocal microscopy images showed that PTOX formed distinct spots in chloroplasts of dark-adapted or uncoupler-treated leaves, while the protein was more equally distributed in a network-like structure in the light. We propose a dynamic PTOX association with the thylakoid membrane depending on the presence of a proton motive force.
ABAS1 from soybean is a 1R-subtype MYB transcriptional repressor that enhances ABA sensitivity
Authors: Ku Yee-Shan , Ni Meng , Muñoz Nacira B , Xiao Zhixia , Lo Annie Wing-Yi , Chen Pei , Li Man-Wah , Cheung Ming-Yan , Xie Min , Lam Hon-Ming
Published: February 2020

Transcription factors (TFs) help plants respond to environmental stresses by regulating gene expression. Up till now, studies on the MYB family of TFs have mainly focused on the highly abundant R2R3-subtype. While the less well-known 1R-subtype has been generally shown to enhance abscisic acid (ABA) sensitivity by acting as transcriptional activators, the mechanisms of their functions are unclear. Here we identified an ABA sensitivity-associated gene from soybean, ABA-Sensitive 1 (GmABAS1), of the 1R-subtype of MYB. Using the GFP-GmABAS1 fusion protein, we demonstrated that GmABAS1 is localized in the nucleus, and with yeast reporter systems, we showed that it is a transcriptional repressor. We then identified the target gene of GmABAS1 to be Glyma.01G060300, an annotated ABI five-binding protein 3 and showed that GmABAS1 binds to the promoter of Glyma.01G060300 both in vitro and in vivo. Furthermore, Glyma.01G060300 and GmABAS1 exhibited reciprocal expression patterns under osmotic stress, inferring that GmABAS1 is a transcriptional repressor of Glyma.01G060300. As a further confirmation, AtAFP2, an orthologue of Glyma.01G060300, was down-regulated in GmABAS1-transgenic Arabidopsis thaliana, enhancing the plant’s sensitivity to ABA. This is the first time a 1R-subtype of MYB from soybean has been reported to enhance ABA sensitivity by acting as a transcriptional repressor.
The Pristine survey – X. A large population of low-metallicity stars permeates the Galactic disc
Authors: Sestito Federico , Martin Nicolas F , Starkenburg Else , Arentsen Anke , Ibata Rodrigo A , Longeard Nicolas , Kielty Collin , Youakim Kristopher , Venn Kim A , Aguado David S , Carlberg Raymond G , González Hernández Jonay I , Hill Vanessa , Jablonka Pascale , Kordopatis Georges , Malhan Khyati , Navarro Julio F , Sánchez-Janssen Rubén , Thomas Guillame , Tolstoy Eline , Wilson Thomas G , Palicio Pedro A , Bialek Spencer , Garcia-Dias Rafael , Lucchesi Romain , North Pierre , Osorio Yeisson , Patrick Lee R , Peralta de Arriba Luis
Published: February 2020

The orbits of the least chemically enriched stars open a window on the formation of our Galaxy when it was still in its infancy. The common picture is that these low-metallicity stars are distributed as an isotropic, pressure-supported component since these stars were either accreted from the early building blocks of the assembling Milky Way (MW), or were later brought by the accretion of faint dwarf galaxies. Combining the metallicities and radial velocities from the Pristine and LAMOST surveys and Gaia DR2 parallaxes and proper motions for an unprecedented large and unbiased sample of 1027 very metal poor stars at [Fe/H] ≤ −2.5 dex, we show that this picture is incomplete. We find that $31{{\ \rm per\ cent}}$ of the stars that currently reside spatially in the disc ($|Z| \le 3{\rm \, kpc}$) do not venture outside of the disc plane throughout their orbit. Moreover, this sample shows strong statistical evidence (at the 5.0σ level) of asymmetry in their kinematics, favouring prograde motion. The discovery of this population implies that a significant fraction of stars with iron abundances [Fe/H] ≤ −2.5 dex merged into, formed within, or formed concurrently with the MW disc and that the history of the disc was quiet enough to allow them to retain their disc-like orbital properties, challenging theoretical and cosmological models.
Mixed diversity of shifting IOD and El Niño dominates the location of Maritime Continent autumn drought
Authors: Hu Chundi , Lian Tao , Cheung Ho-Nam , Qiao Shaobo , Li Zhenning , Deng Kaiqiang , Yang Song , Chen Dake
Published: February 2020

The Maritime Continent is a huge heat source region over the Indo-Pacific warm pool and it plays a key role in global weather/climate variations. The locations of Maritime Continent autumn droughts, linked to frequent rampant forest wildfires, are closely related to the mixed diversity of El Niño and Indian Ocean Dipole events.
Predicting sleep apnea responses to oral appliance therapy using polysomnographic airflow
Authors: Vena Daniel , Azarbarzin Ali , Marques Melania , Op de Beeck Sara , Vanderveken Olivier M , Edwards Bradley A , Calianese Nicole , Hess Lauren B , Radmand Reza , Hamilton Garun S , Joosten Simon A , Taranto-Montemurro Luigi , Kim Sang-Wook , Verbraecken Johan , Braem Marc , White David P , Sands Scott A , Wellman Andrew
Published: February 2020

Study Objectives

Oral appliance therapy is an increasingly common option for treating obstructive sleep apnea (OSA) in patients who are intolerant to continuous positive airway pressure (CPAP). Clinically applicable tools to identify patients who could respond to oral appliance therapy are limited.

Methods

Data from three studies (N = 81) were compiled, which included two sleep study nights, on and off oral appliance treatment. Along with clinical variables, airflow features were computed that included the average drop in airflow during respiratory events (event depth) and flow shape features, which, from previous work, indicates the mechanism of pharyngeal collapse. A model was developed to predict oral appliance treatment response (>50% reduction in apnea–hypopnea index [AHI] from baseline plus a treatment AHI <10 events/h). Model performance was quantified using (1) accuracy and (2) the difference in oral appliance treatment efficacy (percent reduction in AHI) and treatment AHI between predicted responders and nonresponders.

Results

In addition to age and body mass index (BMI), event depth and expiratory “pinching” (validated to reflect palatal prolapse) were the airflow features selected by the model. Nonresponders had deeper events, “pinched” expiratory flow shape (i.e. associated with palatal collapse), were older, and had a higher BMI. Prediction accuracy was 74% and treatment AHI was lower in predicted responders compared to nonresponders by a clinically meaningful margin (8.0 [5.1 to 11.6] vs. 20.0 [12.2 to 29.5] events/h, p < 0.001).

Conclusions

A model developed with airflow features calculated from routine polysomnography, combined with age and BMI, identified oral appliance treatment responders from nonresponders. This research represents an important application of phenotyping to identify alternative treatments for personalized OSA management.
Research translation for military and veteran health: research, practice, policy
Authors: Haibach Jeffrey P , Hoerster Katherine D , Dorflinger Lindsey , McAndrew Lisa M , Cassidy Daniel G , Goodrich David E , Bormann Jill E , Lowery Julie , Asch Steven M , Raffa Susan D , Moin Tannaz , Peterson Alan L , Goldstein Michael G , Neal-Walden Tracy , Talcott Gerald W , Hunter Christopher L , Knight Sara J
Published: February 2020

Military service presents unique challenges and opportunities for health care and public health. In the USA, there are over 2 million military servicemembers, 20 million veterans, and millions more military and veteran family members. Military servicemembers and eligible family members, many veterans, and retirees receive health care through the two largest learning health care systems in the USA, managed and delivered through the Departments of Defense (DoD), Veterans Affairs (VA), and contracted health care organizations. Through a network of collaborative relationships, DoD, VA, and partnering health care and research organizations (university, corporate, community, and government) accelerate research translation into best practices and policy across the USA and beyond. This article outlines military and veteran health research translation as summarized from a collaborative workshop led by experts across health care research, practice, and administration in DoD, VA, the National Institutes of Health, and affiliated universities. Key themes and recommendations for research translation are outlined in areas of: (a) stakeholder engagement and collaboration; (b) implementation science methods; and (c) funding along the translation continuum. Overall, the ability to rapidly translate research into clinical practice and policy for positive health outcomes requires collaborative relationships among many stakeholders. This includes servicemembers, veterans, and their families along with researchers, health care clinicians, and administrators, as well as policymakers and the broader population.
Anti-inflammatory Approach With Early Double Cytokine Blockade (IL-1β and TNF-α) Is Safe and Facilitates Engraftment in Islet Allotransplantation
Authors: Onaca Nicholas , Takita Morihito , Levy Marlon F. , Naziruddin Bashoo
Published: February 2020

Background.

The approach to reducing nonspecific inflammation after islet allotransplantation has been designed to improve engraftment, typically using 1 agent. We report results with the use of combination inflammatory blockade consisting of anti-interleukin (IL)-1β and tumor necrosis factor (TNF)-α.

Methods.

Nine patients underwent islet allotransplantation under a prospective research protocol using double cytokine blockade with anti–TNF-α (etanercept, d 0, 3, 7, 10) and IL-1β (anakinra, d 0–7) at the time of each islet infusion. The primary endpoint, assessed 2 years after the last islet transplant, was the elimination of severe hypoglycemic events and hypoglycemia unawareness, with proper glycemic control, and detectable serum C-peptide.

Results.

No thrombotic events or infectious complications were associated with combined IL-1β and TNF-α blockade. Six patients became insulin independent, 2 had partial function, and 1 had primary nonfunction. After 24-month follow-up, 6 of 9 patients had excellent glycemic control, hemoglobin A1c ≤6.5%, and no episodes of hypoglycemia unawareness. Eight patients developed HLA alloantibodies at various time points (class 1, 5; class 2, 6), with enhanced T-cell alloreactivity. One patient retained good graft function despite having anti-glutamic acid decarboxylase 65 antibodies.

Conclusions.

The use of double cytokine blockade is safe, with reduction of inflammation at transplantation and presumably with better engraftment. However, it does not influence later islet loss from T-cell–mediated autoimmunity and alloimmunity, which require other strategies to maintain long-term islet function.
Rhabdaerophilum calidifontis gen. nov., sp. nov., a novel bacterium isolated from a hot spring, and proposal of Rhabdaerophilaceae fam. nov.
Authors: Ming Yu-Zhen , Liu Lan , Xian Wen-Dong , Jiao Jian-Yu , Liu Ze-Tao , Li Meng-Meng , Xiao Min , Li Wen-Jun
Published: February 2020

A novel thermotolerant bacterial strain was isolated from a hot spring in a Tibetan geothermal field. Phylogenetic analysis of the 16S rRNA gene sequence of the novel strain showed that it belongs to a distinct lineage far from any known taxa. The new isolate shared the highest pairwise sequence identity with

Phreatobacter cathodiphilus

S-12T (92.8 % similarity) according to the 16S rRNA gene sequences. Cells were Gram-stain-negative, aerobic, rod-shaped and formed white round colonies. The strain grew at the ranges of 28–45 °C (optimum, 37 °C), pH 5.0–7.0 (optimum, pH 6.0) and 0–2 % NaCl. The strain was positive for catalase and oxidase. The major respiratory quinone was ubiquinone Q-10. Polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine. The major fatty acids were summed feature 8 (C18 : 1
 ω7c and/or C18 : 1
 ω6c). The DNA G+C content was 68.3 mol%. Based on these distinguishing properties, this strain is proposed to represent a new species of a new genus Rhabdaerophilum calidifontis gen. nov., sp. nov., within a new family Rhabdaerophilaceae fam. nov. The type strain of the type species of Rhabdaerophilum calidifontis is SYSU G02060T (=KCTC 72351T=CGMCC 1.17070T).
Networks of information token recurrences derived from genomic sequences may reveal hidden patterns in epidemic outbreaks: A case study of the 2019-nCoV coronavirus
Authors: Luczak-Roesch Markus
Published: February 2020

Profiling the genetic evolution and dynamic spreading of viruses is a crucial task when responding to epidemic outbreaks. We aim to devise novel ways to model, visualise and analyse the temporal dynamics of epidemic outbreaks in order to help researchers and other people involved in crisis response to make well-informed and targeted decisions about from which geographical locations and time periods more genetic samples may be required to fully understand the outbreak. Our approach relies on the application of Transcendental Information Cascades to a set of temporally ordered nucleotide sequences, and we apply it to real-world data that was collected during the currently ongoing outbreak of the novel 2019-nCoV coronavirus. We assess information-theoretic and network-theoretic measures that characterise the resulting complex network and identify touching points and temporal pathways that are candidates for deeper investigation by geneticists and epidemiologists.
The Novel Coronavirus, 2019-nCoV, is Highly Contagious and More Infectious Than Initially Estimated
Authors: Sanche Steven , Lin Yen Ting , Xu Chonggang , Romero-Severson Ethan , Hengartner Nick , Ke Ruian
Published: February 2020

The novel coronavirus (2019-nCoV) is a recently emerged human pathogen that has spread widely since January 2020. Initially, the basic reproductive number, R0, was estimated to be 2.2 to 2.7. Here we provide a new estimate of this quantity. We collected extensive individual case reports and estimated key epidemiology parameters, including the incubation period. Integrating these estimates and high-resolution real-time human travel and infection data with mathematical models, we estimated that the number of infected individuals during early epidemic double every 2.4 days, and the R0 value is likely to be between 4.7 and 6.6. We further show that quarantine and contact tracing of symptomatic individuals alone may not be effective and early, strong control measures are needed to stop transmission of the virus.

One-sentence summary

By collecting and analyzing spatiotemporal data, we estimated the transmission potential for 2019-nCoV.
Tumor Phylogeny Topology Inference via Deep Learning
Authors: Azer Erfan Sadeqi , Ebrahimabadi Mohammad Haghir , Malikić Salem , Khardon Roni , Sahinalp S. Cenk
Published: February 2020

Principled computational approaches for tumor phylogeny reconstruction via single-cell sequencing typically aim to build the most likely perfect phylogeny tree from the noisy genotype matrix - which represents genotype calls of single-cells. This problem is NP-hard, and as a result, existing approaches aim to solve relatively small instances of it through combinatorial optimization techniques or Bayesian inference. As expected, even when the goal is to infer basic topological features of the tumor phylogeny - rather than reconstructing the topology entirely, these approaches could be prohibitively slow. In this paper, we introduce fast deep-learning solutions to the problems of inferring whether the most likely tree has a linear (chain) or branching topology and whether a perfect phylogeny is feasible from a given genotype matrix. We also present a reinforcement learning approach for reconstructing the most likely tumor phylogeny. This preliminary work demonstrates that data-driven approaches can reconstruct key features of tumor evolution.
Prevention of adrenal crisis: cortisol responses to major stress compared to stress dose hydrocortisone delivery in adrenal insufficiency
Authors: Prete Alessandro , Taylor Angela E , Bancos Irina , Smith David J , Foster Mark A , Kohler Sibylle , Fazal-Sanderson Violet , Komninos John , O’Neil Donna M , Vassiliadi Dimitra A , Mowatt Christopher J , Mihai Radu , Fallowfield Joanne L , Annane Djillali , Lord Janet M , Keevil Brian G , Wass John AH , Karavitaki Niki , Arlt Wiebke
Published: February 2020

Context

Patients with adrenal insufficiency require increased hydrocortisone cover during major stress to avoid life-threatening adrenal crisis. However, current treatment recommendations are not evidence-based.

Objective

To identify the most appropriate mode of hydrocortisone delivery in patients with adrenal insufficiency exposed to major stress.

Design and Participants

Cross-sectional study: 122 unstressed healthy subjects and 288 subjects exposed to different stressors (major trauma [N=83], sepsis [N=100], and combat stress [N=105]). Longitudinal study: 22 patients with preserved adrenal function undergoing elective surgery. Pharmacokinetic study: 10 patients with primary adrenal insufficiency undergoing administration of 200mg hydrocortisone over 24 hours in four different delivery modes (continuous intravenous infusion; six-hourly oral, intramuscular or intravenous bolus administration).

Main Outcome Measure

We measured total serum cortisol and cortisone, free serum cortisol and urinary glucocorticoid metabolite excretion by mass spectrometry. Linear pharmacokinetic modelling was used to determine the most appropriate mode and dose of hydrocortisone administration in patients with adrenal insufficiency exposed to major stress.

Results

Serum cortisol was increased in all stress conditions, with the highest values observed in surgery and sepsis. Continuous intravenous hydrocortisone was the only administration mode persistently achieving median cortisol concentrations in the range observed during major stress. Linear pharmacokinetic modelling identified continuous intravenous infusion of 200mg hydrocortisone over 24 hours, preceded by an initial bolus of 50-100mg hydrocortisone, as best suited for maintaining cortisol concentrations in the required range.

Conclusions

Continuous intravenous hydrocortisone infusion should be favored over intermittent bolus administration in the prevention and treatment of adrenal crisis during major stress.