bluuebunny/crossref_metadata_2025 huggingface dataset:
Crianças com paralisia cerebral: como podemos avaliar e manejar seus aspectos nutricionais
Authors: Mota Marília Alonso , Silveira Carla Rosane Moraes , de Mello Elza Daniel
Published: February 2020

Introdução: A população de crianças portadoras de paralisia cerebral (PC) vem crescendo ao passar dos anos. Estima-se que se tenha de 30.000 a 40.000 casos novos por ano no Brasil. Nesse sentido, os profissionais de saúde devem estar preparados para atender essa população. A classificação do estado nutricional adequada para a população de PC, otimiza uma intervenção nutricional adequada. E, é importante levar em consideração, no momento da avaliação nutricional, que as crianças com PC têm características próprias como distúrbios de deglutição e déficit motores, não devendo ser avaliadas da mesma forma que crianças saudáveis. Neste sentido o objetivo deste estudo é revisar na literatura métodos de avaliação nutricional e terapia nutricional utilizados em crianças e adolescentes com paralisia cerebral.

Fonte de dados: Artigos indexados nas bases de dados MEDLINE, SCIELO, além de referências clássicas. As palavras utilizadas foram: “paralisia cerebral”, “avaliação nutricional”, “curvas de crescimento” e “terapia nutricional”.

Conclusões: Percebe-se que não está bem definido quais métodos devem ser utilizados na avaliação nutricional dos pacientes com PC. Nesse sentido, está sendo salientado aspectos importantes no atendimento nutricional de crianças com PC.
Epigenetics and the exposomes: Obesity and beyond
Authors: Raman Rita P. , Raman Anita D.
Published: February 2020

The specific genetic alterations that result in diseases and complex syndromes have been and continue to be identified. Search for the origins of disease have led to investigations into the roles of dietary and environmental factors as potential triggers or modifiers of risk. Genome-wide association studies have identified concepts such as the rare variant-common disease hypothesis and the common variant-common disease hypothesis.1 Through association studies, unique gene-environment interactions, which may occur with or without specific periods of permissiveness or vulnerabilities, have also been identified. Major conditions where the role of exposomes and epigenetics are rapidly evolving are obesity, neurological disorders, immune disorders and cancers. These concepts are particularly intriguing in the context of obesity.

BACKGROUND:

Epigenetics can be defined as heritable traits resulting from changes in DNA or chromatin structure without alterations in the DNA sequence.2 Nutritional epigenetics is seen as a means for the prevention of developmental diseases and cancer, and to delay processes associated with aging.3,4 Diseases in which epigenetic factors are considered significant include type 2 diabetes mellitus, obesity, inflammation, cardiovascular diseases, neurocognitive disorders, and immune diseases, with neural function influenced by environmental factors including early experience.5 Studies with rodent models suggest that during both early development and in adult life, environmental signals can activate intracellular pathways that directly remodel the epigenome, leading to changes in gene expression and function. These studies define a biological basis for the interplay between environmental signals and the genome in the regulation of individual differences in behavior, cognition, and physiology.6 In reproduction, certain genes are turned on while others are turned off in the process of imprinting. In the case of imprinting, even though there are two copies of the gene, only one copy is expressed and there is no substitute functional allele. For this reason, imprinting makes the imprinted genes more vulnerable to the negative effects of mutations.7
Ecocardiografia para avaliação cardiovascular de crianças com sobrepeso/obesidade: uma revisão
Authors: Caixe Simone Helena , de Almeida Carlos Alberto Nogueira
Published: February 2020

No Brasil, os dados atuais mostram que a prevalência de sobrepeso e obesidade em crianças é elevada e crescente. Diante deste cenário torna-se necessário detectar precocemente alterações cardiovasculares decorrentes desse quadro. A presente revisão é um estudo descritivo exploratório que trata da utilização da ecocardiografia transtorácica no diagnóstico das alterações cardiovasculares e incluiu publicações indexadas em bases de pesquisa científica, MEDLINE, SCIELO, e referências clássicas no período de 2001 a 2013. Os termo de procura usados foram: “obesidade”, “ecocardiograma transtorácico”, “alterações cardiovasculares”. A ecocardiografia transtorácica avalia com precisão e em tempo real, a estrutura e o funcionamento cardíaco, por meio dos parâmetros ecocardiográficos e por isso possibilita detectar alterações precoces da função diastólica e da geometria ventricular esquerda.
Prevalência de diabetes e intolerância a glicose em pacientes com dor crônica
Authors: Higashi Rafael , Higashi Leonardo , Higashi Andrea Nunes , Soares Marco Antonio Botelho
Published: February 2020

Justificativa e objetivos: A diabetes é associada ao aumento de prevalência de dor crônica, porém faltam estudos que associem dor crônica como um sintoma precoce de intolerância a glicose ou diabetes. O objetivo deste estudo foi avaliar na população adulta a prevalência de diabetes e intolerância a glicose em pacientes com dor crônica comparado com pacientes sem dor crônica em um ambulatório privado especializado em nutrologia. Método: Foram incluídos 60 pacientes, 30 pacientes com dor crônica com duração de pelo menos 3 meses e 30 pacientes sem queixa de dor crônica. Todos os pacientes foram estudados prospectivamente para o diagnóstico de diabetes ou intolerância a glicose por meio do teste de tolerância oral com medição glico-insulinica basal a após 2 horas, após estímulo de 75 gramas de glicose. Resultados: Dos 30 indivíduos com dor crônica, 6 pacientes (20%) tinham diabetes, 3 pacientes (10%) tinham intolerância a glicose, totalizando 9 pacientes (30%) com alteração dos níveis glicêmicos (pré-diabético ou diabético). Dos 30 indivíduos sem dor crônica, 1 paciente (3,3%) foi diagnosticado como diabético, 3 pacientes (10%) com intolerância a glicose, totalizando 4 pacientes (13,3%) com alteração dos níveis glicêmicos (pré-diabético ou diabético). Conclusão: Houve significância estatística na prevalência de alteração do nível glicêmico em pacientes com dor crônica em comparação com pacientes sem queixa de dor crônica.
Expert-augmented machine learning
Authors: Gennatas Efstathios D. , Friedman Jerome H. , Ungar Lyle H. , Pirracchio Romain , Eaton Eric , Reichmann Lara G. , Interian Yannet , Luna José Marcio , Simone Charles B. , Auerbach Andrew , Delgado Elier , van der Laan Mark J. , Solberg Timothy D. , Valdes Gilmer
Published: February 2020

Machine learning is proving invaluable across disciplines. However, its success is often limited by the quality and quantity of available data, while its adoption is limited by the level of trust afforded by given models. Human vs. machine performance is commonly compared empirically to decide whether a certain task should be performed by a computer or an expert. In reality, the optimal learning strategy may involve combining the complementary strengths of humans and machines. Here, we present expert-augmented machine learning (EAML), an automated method that guides the extraction of expert knowledge and its integration into machine-learned models. We used a large dataset of intensive-care patient data to derive 126 decision rules that predict hospital mortality. Using an online platform, we asked 15 clinicians to assess the relative risk of the subpopulation defined by each rule compared to the total sample. We compared the clinician-assessed risk to the empirical risk and found that, while clinicians agreed with the data in most cases, there were notable exceptions where they overestimated or underestimated the true risk. Studying the rules with greatest disagreement, we identified problems with the training data, including one miscoded variable and one hidden confounder. Filtering the rules based on the extent of disagreement between clinician-assessed risk and empirical risk, we improved performance on out-of-sample data and were able to train with less data. EAML provides a platform for automated creation of problem-specific priors, which help build robust and dependable machine-learning models in critical applications.
AB569, a nontoxic chemical tandem that kills major human pathogenic bacteria
Authors: McDaniel Cameron T. , Panmanee Warunya , Winsor Geoffrey L. , Gill Erin , Bertelli Claire , Schurr Michael J. , Dongare Prateek , Paul Andrew T. , Ko Seung-Hyun B. , Lau Gee W. , Dasgupta Nupur , Bogue Amy L. , Miller William E. , Mortensen Joel E. , Haslam David B. , Dexheimer Phillip , Muruve Daniel A. , Aronow Bruce J. , Forbes Malcolm D. E. , Danilczuk Marek , Brinkman Fiona S. L. , Hancock Robert E. W. , Meyer Thomas J. , Hassett Daniel J.
Published: February 2020

Antibiotic-resistant superbug bacteria represent a global health problem with no imminent solutions. Here we demonstrate that the combination (termed AB569) of acidified nitrite (A-NO
2
−
) and Na
2
-EDTA (disodium ethylenediaminetetraacetic acid) inhibited all Gram-negative and Gram-positive bacteria tested. AB569 was also efficacious at killing the model organism
Pseudomonas aeruginosa
in biofilms and in a murine chronic lung infection model. AB569 was not toxic to human cell lines at bactericidal concentrations using a basic viability assay. RNA-Seq analyses upon treatment of
P. aeruginosa
with AB569 revealed a catastrophic loss of the ability to support core pathways encompassing DNA, RNA, protein, ATP biosynthesis, and iron metabolism. Electrochemical analyses elucidated that AB569 produced more stable SNO proteins, potentially explaining one mechanism of bacterial killing. Our data implicate that AB569 is a safe and effective means to kill pathogenic bacteria, suggesting that simple strategies could be applied with highly advantageous therapeutic/toxicity index ratios to pathogens associated with a myriad of periepithelial infections and related disease scenarios.
Foxn4 is a temporal identity factor conferring mid/late-early retinal competence and involved in retinal synaptogenesis
Authors: Liu Shuting , Liu Xiaoning , Li Shengguo , Huang Xiuting , Qian Haohua , Jin Kangxin , Xiang Mengqing
Published: February 2020

Significance

Organogenesis, an evolutionarily refined process which is so complicated, delicate, yet replicable, is all about time and space. Only until recently have scientists realized that the temporal identity ofDrosophilaneuroblasts is controlled by cascades of temporal transcription factors (tTFs), but the temporal regulation mechanism is poorly understood in vertebrates. We show that Foxn4 functions as a tTF to confer mammalian retinal progenitors (RPCs) with the competence to generate mid/late-early cell types while suppressing the immediate-early cell type. Our data thus identify a missing member of the tTF cascade that controls RPC temporal identities to ensure the generation of proper retinal neuronal diversity, and provide an important insight for understanding how cell-fate transitions are guided during vertebrate organogenesis.
Any #JesuisIraq planned?*
Authors: De Cock Barbara , Pizarro Pedraza Andrea
Published: February 2020

The stem#jesuisfollowed by a toponym (e.g.#jesuisParis)has proved to be very productive in the gathering of affective publics (Papacharissi 2015) around causes of mourning, after terrorist attacks and other disasters. However, not all attacks have given rise to such massive affective use of#jesuishashtags. Our goal is to examine how Twitter users claim similar displays of affect for these “other” places. We analyze 297 tweets in which the Twitter user utters a condolence speech act while simultaneously contesting the unbalanced affective reactions expressed concerning some places, e.g. “Any #JesuisIraq planned?”. We observe the geographical granularity of the referred place, the structural complexity of the tweet and, if present, the underlying motives for unbalanced reactions suggested by the Twitter users. By doing so, we show how Twitter is used to claim attention for places that are deemed underrepresented, thus confirming the importance of Twitter for expressing solidarity.
Location of neonatal microglia drives small extracellular vesicles content and biological functions in vitro
Authors: Murgoci Adriana‐Natalia , Duhamel Marie , Raffo‐Romero Antonella , Mallah Khalil , Aboulouard Soulaimane , Lefebvre Christophe , Kobeissy Firas , Fournier Isabelle , Zilkova Monika , Maderova Denisa , Cizek Milan , Cizkova Dasa , Salzet Michel
Published: February 2020

Combining proteomics and systems biology approaches, we demonstrate that neonatal microglial cells derived from two different CNS locations, cortex and spinal cord, and cultured in vitro displayed different phenotypes upon different physiological or pathological conditions. These cells also exhibited greater variability in terms of cellular and small extracellular vesicles (sEVs) protein content and levels. Bioinformatic data analysis showed that cortical microglia exerted anti‐inflammatory and neurogenesis/tumorigenesis properties, while the spinal cord microglia were more inflammatory. Interestingly, while both sEVs microglia sources enhanced growth of DRGs processes, only the spinal cord‐derived sEVs microglia under LPS stimulation significantly attenuated glioma proliferation. These results were confirmed using the neurite outgrowth assay on DRGs cells and glioma proliferation analysis in 3D spheroid cultures. Results from these in vitro assays suggest that the microglia localized at different CNS regions can ensure different biological functions. Together, this study indicates that neonatal microglia locations regulate their physiological and pathological functional fates and could affect the high prevalence of brain vs spinal cord gliomas in adults.
Optimization of upconversion luminescence excitation mode for deeper in vivo bioimaging without contrast loss or overheating
Authors: Pominova Daria V , Romanishkin Igor D , Proydakova Vera Yu , Grachev Pavel V , Moskalev Arkadiy S , Ryabova Anastasia V , Makarov Vladimir I , Linkov Kirill G , Kuznetsov Sergei V , Voronov Valerii V , Uvarov Oleg V , Loschenov Victor B
Published: February 2020

Upconversion nanoparticles have attracted considerable attention as luminescent markers for bioimaging and sensing due to their capability to convert near-infrared (NIR) excitation into visible or NIR luminescence. However, the wavelength of about 970 nm is commonly used for the upconversion luminescence excitation, where the strong absorption of water is observed, which can lead to laser-induced overheating effects. One of the strategies for avoiding such laser-induced heating involves shifting the excitation into shorter wavelengths region. However, the influence of wavelength change on luminescent images quality has not been investigated yet. In this work, we compare wavelengths of 920, 940 and 970 nm for upconversion luminescence excitation in the thickness of biological tissues in terms of detected signal intensity and obtained image quality (contrast and signal-to-background ratio). Studies on biological tissue phantoms with various scattering and absorbing properties were performed to analyze the influence of optical parameters on the depth and contrast of the images obtained under 920–970 nm excitation. It was shown that at the same power the excitation wavelength shift reduces the detected signal intensity and the resulting image contrast. Visualization of biological tissue samples using shorter excitation wavelengths 920 and 940 nm also reduces signal-to-background ratio (S/B) of the obtained images. The S/B of the obtained images amounted to 2, 6 and 8 for 920, 940 and 970 nm, respectively. It was demonstrated that pulse-periodic excitation mode is preferable for obtaining high quality luminescent images of biological tissues deep layers and minimize overheating. Short pulse durations (duty cycle 20%) don’t result in heating even for 1 W cm−2 pumping power density and allow obtaining high luminescence intensity, which provides good images quality.
DeepMAsED: evaluating the quality of metagenomic assemblies
Authors: Mineeva Olga , Rojas-Carulla Mateo , Ley Ruth E , Schölkopf Bernhard , Youngblut Nicholas D
Published: February 2020

Motivation

Methodological advances in metagenome assembly are rapidly increasing in the number of published metagenome assemblies. However, identifying misassemblies is challenging due to a lack of closely related reference genomes that can act as pseudo ground truth. Existing reference-free methods are no longer maintained, can make strong assumptions that may not hold across a diversity of research projects, and have not been validated on large-scale metagenome assemblies.

Results

We present DeepMAsED, a deep learning approach for identifying misassembled contigs without the need for reference genomes. Moreover, we provide an in silico pipeline for generating large-scale, realistic metagenome assemblies for comprehensive model training and testing. DeepMAsED accuracy substantially exceeds the state-of-the-art when applied to large and complex metagenome assemblies. Our model estimates a 1% contig misassembly rate in two recent large-scale metagenome assembly publications.

Conclusions

DeepMAsED accurately identifies misassemblies in metagenome-assembled contigs from a broad diversity of bacteria and archaea without the need for reference genomes or strong modeling assumptions. Running DeepMAsED is straight-forward, as well as is model re-training with our dataset generation pipeline. Therefore, DeepMAsED is a flexible misassembly classifier that can be applied to a wide range of metagenome assembly projects.

Availability and implementation

DeepMAsED is available from GitHub at https://github.com/leylabmpi/DeepMAsED.

Supplementary information

Supplementary data are available at Bioinformatics online.
Atrial thrombi or cardiac tumours? The image-challenge of intracardiac masses: a case report
Authors: Castrichini Matteo , Albani Stefano , Pinamonti Bruno , Sinagra Gianfranco
Published: February 2020

Background

Cardiac masses (CM) encompass a broad set of lesions that can be either neoplastic or non-neoplastic. A stepwise diagnostic strategy through multimodality imaging evaluation is the cornerstone for the appropriate approach.

Case summary

We report the case of an 83-year-old man presenting at the emergency department for acute heart failure showing bilateral atrial masses without unequivocal aetiological aspects at several imaging techniques, emphasizing the critical aspects in the differential diagnosis.

Discussion

In the complex field of CM, a proper differential diagnosis is very important in order to start the appropriate treatment; however, sometimes it could be challenging despite a multimodality imaging approach, therefore still requiring histologic examination.
Ten lessons from the frontlines of science in support of fisheries management
Authors: Hare Jonathan A
Published: February 2020

After 20+ years as a research scientist, I recently made a career change to a scientific administrator in NOAA Fisheries. Part of the NOAA Fisheries mission is to provide scientific advice for fisheries using ecosystem based approaches to management. Where I used to see fisheries science as a relatively straightforward discipline, I now recognize fisheries as a complex socio-ecological system that spans natural and social sciences. With this recognition has come an appreciation for the concept of wicked problems and for the incremental approach to policy-making. Here I describe my perspectives before and after this recognition and present 10 lessons for myself as a guide to providing science in support of fisheries management.
Gas-Liquid Chromatographic Determination of Chlordene Epoxide in Catfish
Authors: Castillo Gabriel D , Jeffus Marshall T , Kenner Charles T
Published: February 2020

Chlordene epoxide was detected in the range of 0.04 to 0.27 ppm in the edible portion of 3 catfish samples during the analysis of 36 fish samples by electron capture gas-liquid chromatography (GLC) for pesticide and industrial chemical residues. Two of these catfish samples were from suppliers in Louisiana and the third was from a Texas supplier. Chlordene was also present; the amount of chlordene epoxide in the 3 samples averaged 46% of the amount of chlordene present. The epoxide was identified by comparison of the mass spectra and the CLC retention times of the samples with reference material prepared in this laboratory.
Program for Computation of Response Data from Five Different Gas Chromatograph Detectors Operating Simultaneously
Authors: Mcleod Harry A , Lewis David
Published: February 2020

A novel digital computer program for evaluating data from a gas chromatograph with 5 different detectors—electron capture, flame ionization, nitrogen, phosphorus, and sulfur—operating simultaneously is described. Detector signals are recorded on a 9-channel incremental tape, and then processed off-line by using a NOVA 8K computer system. Spurious signals from each detector are minimized by applying a simplified least squares smoothing procedure to the raw data points. Peak detection logic operating parameters may be varied for each detector. Relative retention times are calculated for 2 internal standards as references and peak areas are corrected for baseline drift. Operator interaction is maximal and several different data reporting formats are used to tabulate the raw and processed data.
Gas-Liquid Chromatographic Determination of Chlorinated Norbornene Derivatives in Fish
Authors: Yurawecz Martin P , Roach John A G
Published: February 2020

1,2,3,4,7,7 - Hexachloro - 2,5 - norbornadiene (I), 1,2,3,4,5 - endo,7,7 - heptachloro - 2 - norbornene (II), and l,2,3,4,7,7-hexachloro-5,6-erecfoepoxy- 2-norbornene (III) have been identified as contaminants in Mississippi River fish by combined gas-liquid chromatography (GLC)- mass spectrometry. The method used to determine residues of these compounds, which are associated with production of the pesticide endrin, is similar to the AOAC multiresidue method for chlorinated pesticides. The residues are extracted from the sample with acetonitrile, transferred to petroleum ether, and chromatographed on a Florisil column. Compounds I and II are eluted from the Florisil with petroleum ether and compound III is eluted with ethyl ether-petroleum ether (6+94). The concentrated eluates are analyzed by using electron capture GLC. The method provides adequate recoveries of all 3 chlorinated norbornene derivatives and allows quantitation at or below the 0.05 ppm level in fish with a 20 mg sample equivalent injection.
Critical Review of AOAC Fluorometric Method for Determining Selenium in Foods
Authors: Michie Norman D , Dixon E John , Bunton Norman G
Published: February 2020

The AOAC fluorometric method for determining selenium in foods is reviewed. A modified method of sample digestion is proposed, together with some minor alterations to the fluorometric method. A mixture of nitric and perchloric acids is used for sample digestion in place of nitric, perchloric, and sulfuric acids. Sulfuric acid is added after digestion to remove the other acids, and provide a constant and known matrix for complexation with DAN. Hydrogen peroxide is added in order to convert all Se(VI) to Se(IV). The pH of the digest is controlled by adding glycine/HCl buffer before adding ammonia. Samples are heated at a lower temperature and longer time for complexation. DAN reagent is prepared fresh daily.
Spectrophotometric Determination of Strychnine and Brucine in Liquid Galenicals
Authors: El-Masry Sawsan , Wahbi Abdel-Aziz M
Published: February 2020

A rapid method is presented for determining strychnine and brucine in liquid galenicals. At pH 5.0, both strychnine and brucine are complexed with methyl orange. After treatment with 0.1N NaOH, the liberated alkaloids are determined spectrophotometrically, using the 2-wavelength method of analysis. The method has been successfully applied to the analysis of 4 batches of nux vomica tincture, nux vomica acid, and nux vomica alkaline mixtures. The method has a relative standard deviation of 0.52%.
Scanning Electron Microscopic Study of Adult Stored Product Beetle Elytra
Authors: Kvenberg John E
Published: February 2020

Scanning electron microscopy was used to establish the microstructure of adult stored product beetle elytra. Twenty-three species of major importance, which commonly occur in food products, are illustrated. Micrographs and accompanying narrative descriptions provide a definitive diagnostic reference for the identification of elytral fragments examined by light microscopy.
Analysis of Fat-Soluble Vitamins. XIX. Collaborative Studies on the Chemical Assay for Vitamin D Concentrates
Authors: Mulder Frits J , Borsje Ben , Strik Roel , Vries Ellen J
Published: February 2020

In 1971, a chemical method for the assay of vitamin D in concentrates containing only vitamin D was collaboratively studied by 14 laboratories, using 6 different samples from 2 European manufacturers. On the basis of these results, the laboratories were divided into 2 groups: 5 with significant laboratory biases of ≥2%, and 9 laboratories with nonsignificant bias. The 9 laboratories were subdivided into 2 groups which differed significantly as to reproducibility within laboratories. The reproducibility between laboratories, expressed as a standard deviation in per cent with 95% confidence limits, was 1.2% (confidence range 0.6–7.3) and 4.7% (confidence range 2.4–29.3) for 3 and 6 laboratories, respectively. A second collaborative test was performed in 1974, using 12 vitamin D resin samples in oil from 3 United States manufacturers, to compare 2 chemical vitamin D assay methods (with and without maleic anhydride) and to compare results from the chemical and biological methods; 9 laboratories participated in the chemical method study and 3 in the rat bioassay study. The correlation of results of the chemical method including maleic anhydride treatment and the rat bioassays was satisfactory. The reproducibility of the chemical method was about the same as that in the first collaborative test.
Total Volatile Acidity in Wines, Exclusive of Sulfur Dioxide: Collaborative Study
Authors: Pilone Gordon J
Published: February 2020

Two methods for determining total volatile acidity in wines, exclusive of sulfur dioxide, were collaboratively studied by using a matched pair scheme. Both methods required an alkali titration of a steam distillate of wine. With one method, the titration of the distillate gave total volatile acidity measurements exclusive of sulfur dioxide when mercuric ions were present during distillation (direct-titration method). With the other method, the interferences of free and bound sulfur dioxide were excluded following the alkali titration by titrating their equivalence as acetic acid with iodine (back-titration method). This required additional manipulation of the sample, including 2 extra titrations. The results of the collaborative study showed that although the mean measurements for both methods were close, variability in repeatability and reproducibility was always smaller (both among and within laboratories) for the directtitration method. This method has been adopted as official first action.
Total Nitrogen in Fertilizer: Collaborative Study
Authors: Rexroad Paul R , Krause Gary F
Published: February 2020

A modified comprehensive nitrogen method, using 0.4 g C11SO4 as catalyst, is presented. This method plus a modified Raney powder method (mercury-free) with no metallic oxidation catalyst are compared with the AOAC comprehensive nitrogen method. Results from 19 collaborating laboratories for 11 samples are evaluated. The modified Raney method gave significantly low results on 2 samples: 21-7-14 (nitric phosphates-non-sulfate sulfur) and tryptophan. The results for the average per cent nitrogen for 11 samples from the modified comprehensive nitrogen method were comparable to those from the official method at the 95 % probability level; the overall pooled standard deviations were also similar. In this collaborative study, the modified method (with copper) was equal in accuracy and precision to the official method (with mercury). The modified comprehensive nitrogen method has been adopted as official first action.
DC Arc Plasma Emission Spectrometric Determination of Boron in Plants
Authors: Melton James R , Hoover William L , Morris Patricia A , Gerald Janette A
Published: February 2020

A dc arc plasma emission method is described for determining boron in plants at levels of ≧2.5 ≧g/g. The sample is wet-digested and analyzed at 2497.73A. Lithium is added to mask enhancement of emission by other alkali metals. Results for boron determined by the described method and atomic absorption spectrophotometry compared favorably. Recoveries of boron added to plants ranged from 90.4 to 104.4% with a mean recovery of 99.7%. The described method is convenient, rapid, and accurate for determining boron in plants.
A Rapid Gas-Liquid Chromatographic Method for the Multidetermination of Antioxidants in Fats, Oils, and Dried Food Products
Authors: Kline David A , Joe Frank L , Fazio Thomas
Published: February 2020

A rapid quantitative method for determining 8 antioxidants in various food products is described. Two procedures are employed. The first involves the use of a glass wool precolumn to separate 3(2)-tert-butyl-4-hydroxyanisole, 3,5-di -tert - butyl - 4 - hydroxytoluene, 4 - hydroxymethyl- 2,6-di-tert-butylphenol, and mono-tertbutylhydroquinone (TBHQ) from nonvolatile residues resulting from direct injection of diluted sample or sample extracts into the gasliquid chromatographic (GLC) column. In the second procedure, the antioxidants TBHQ, 3,3'- thiodipropionic acid, n-propyl gallate, 2,4,5- trihydroxybutyrophenone, and nordihydroguaiaretic acid are isolated from food products by extraction with 70% ethanol. The antioxidant residues are then converted to trimethylsilyl derivatives, and determined by GLC, using a flame ionization detector. Recoveries of all 8 antioxidants from 28 food samples fortified at either 10 or 100 ppm ranged from 70 to 105%.
Improved Microbiological Assay for Penicillin Residues in Tissues and Stability of Residues Under Cooking Procedures
Authors: Katz Stanley E , Fassbender Carol A , Depaolis Anneli M , Rosen Joseph D
Published: February 2020

The microbiological assay for penicillin residues was improved by using centrifugation to remove physical barriers to diffusion, a small buffer/meat extraction ratio, and a more sensitive 2-layer assay system. Recoveries from muscle, kidney, and liver tissues ranged between 70.1 and 86.7% with measurable levels of 0.03- 0.05 unit/g. By comparison, the Food and Drugsuggested methodology yielded recoveries of 45.9-54.0% and levels of detectability of 0.08- 0.10 unit/g. Cooking of hamburger, steaks, and pork chops indicated that procaine penicillin withstood cooking conditions, and significant levels of the original activity remained.
pH-Induced Difference Spectrophotometric Assay of Acetazolamide, Hydrochlorothiazide, and Furosemide
Authors: Abdine Hassan , Abdel-Hady Elsayed M , Elsayed Yousry M
Published: February 2020

On the basis of pH-induced spectral changes for acetazolamide, hydrochlorothiazide, and furosemide, 3 different spectrophotometric methods are described. The methods were successfully applied to the assay of these drugs in different pharmaceutical formulations (tablets and ampoules). The accuracy of the analysis is increased by using the suggested methods as compared with conventional spectrophotometry.
Measurement of the Bioavailability of Iron, Using the Rat Hemoglobin Repletion Test
Authors: Fritz James C , Pla Gwendolyn W , Harrison Bertha N , Clark Geneva A , Smith Edythe A
Published: February 2020

Variations in the AOAC official first action rat hemoglobin repletion test for iron were studied. These changes included (1) use of a simplified basal diet to eliminate ingredients which sometimes contribute too much iron; (2) increased fortification of the basal diet with vitamin E, pantothenic acid, and pyridoxine; (3) increased dietary copper; (4) variations in the carbohydrate source in the basal diet; (5) changes in the length of the depletion and repletion periods; and (6) comparison of prophylactic and curative procedures. The changes yielded results comparable to those obtained with the present official method. Further study may reveal that the depletion period can be shortened or eliminated. To fully meet the rat's vitamin requirements, increased levels of vitamin E, pantothenic acid, and pyridoxine are recommended. It is further recommended that the present method remain in official first action status, and that study be continued.
Problems in the Recovery and Identification of Yersinia from Food
Authors: Mehlman Ira J , Aulisio Calvin C G , Sanders Arvey C
Published: February 2020

Y. enterocolitica and Y. pseudotuberculosis are emerging foodborne pathogens. Phosphatesaline enrichment of food homogenates at 4°C required about 2 weeks for retrieval of yersinia when present at 10,000/g. Modification by inclusion of 1% sorbitol and 0.15% bile salts increased sensitivity 10-fold and extended the recovery period. MacConkey was superior to bismuth-sulfite, Salmonella-Shigella, Hektoen, and Levine EMB agars for isolation. Incubation at 26°C was more satisfactory for recovery and characterization than 37°C. Isolates were first screened in TSI, mannitol, and lysine which eliminated 75% of interfering cultures. Of 25 biochemicals evaluated, urea, arginine, motility (at 26 and 37C°), and phenylalanine were most useful for confirmation. Cultures isolated from foods were classified into 2 groups (1) giving negative reactions in citrate, raffinose, melibiose, and gelatin; and (2) giving positive reactions in the above biochemicals. The former resembled classical European strains of Y. enterocolitica. The latter were more frequently recovered and designated Y. enterocolitica-like bacteria.
Fecal Coliform Methods for Examination of Sea Water: Interlaboratory Evaluation of Split Sample Analysis
Authors: Miescier John J , Carr Virgil E , Musselman John F , Furfari Santo A
Published: February 2020

An interlaboratory study was conducted to compare the effectiveness of the following 3 multiple-tube fermentation methods for determining the most probable number (MPN) of Escherichia coli in a split artificial sea water sample: ( 1 ) the 72-hr standard methods procedure of the American Public Health Association, (2) a 24-hr elevated-temperature test using A-l medium, and (3) a 24-hr elevated temperature test modified to include an initial 3-hr resuscitation period using A-l medium. The capability of the laboratories to perform the 3 test procedures was also compared. Split sample replicates with low, medium, and high levels of E. coli were examined in 18 laboratories in the United States and Canada. Data indicate that the laboratories performed each test with equal capability, and all 3 procedures were equally effective in enumerating the strain of E. coli used in this investigation. By virtue of its homogeneity and stability, the split sample served as an appropriate specimen for this study and could probably be used as a proficiency test specimen for evaluating laboratory analyst performance in the bacteriological examination of sea water.
Gas-Liquid Chromatography of Aqueous-Alcohol Solutions for Insecticide Residue Analysis
Authors: Sans Walter W
Published: February 2020

Injection of water-methanol solutions of insecticides into a gas-liquid chromatograph, equipped with alkali flame ionization and electron capture detectors, is a simplified, cost-saving technique for obtaining analytical data since the most economical solvents are used and time spent on extraction is eliminated. The procedure has been used to obtain water-solubility values for 20 insecticides ranging from 0.09 ppm (iodofenfos) to 4000 ppm (disulfoton sulfoxide) and for determining equilibrium concentrations of insecticides in clay-water suspensions. The usefulness of this technique is limited by the sensitivity of the gas chromatographic system which may require concentration of the extracts, and the stability of the compound in an aqueous system.
Gas-Liquid Chromatographic Determination of Selenium in Biological Materials, Using 4-Bromo- and 4-Chloro-1,2-Diaminobenzene as Derivatizing Reagents
Authors: Bycroft Brian M , Clegg Donald E
Published: February 2020

A method is described for the gas-liquid chromatographic determination of traces of selenium in marine biological materials. The method is based on the reaction of Se(IV) with bromo- and chloro-substituted 1,2-diaminobenzenes. The benzoselenadiazoles so formed are sensitive to electron capture detection. The sample is digested in a nitric-perchloric acid mixture and selenium is reduced to the IV oxidation state. Different aliquots of the digest solution are reacted with either 4-bromo- or 4-chloro-l,2-diaminobenzene to quantitatively form the corresponding 2,1,3-benzoseIenadiazole. Recovery of added selenite to a fish meal sample was 95% for the bromo derivative and 101% for the chloro derivative. Different portions of a well mixed fish meal sample were analyzed in independent laboratories by the fluorometric method and by atomic absorption spectrophotometry (hydride generation). The following mean values (μg/g) were found: present method 1.89, fluorometric method 1.91, atomic absorption method 2.1. The lower limit of detection for the method described was 13 ng, using the bromo derivative, and 27 ng, using the chloro derivative.
Spectrofluorometric Determination of Atropine-Hyoscyamine in Tablets and Powders
Authors: Cieri Ugo R
Published: February 2020

A method is presented for determining atropine-hyoscyamine alkaloids in tablets and powders by spcetrofluorometry. The sample is first shaken with 0.1N H2S04 solution; then an aliquot containing about 0.1 mg alkaloid is transferred to a separatory funnel, made basic with NaOH solution, and extracted with CHC13. The extract is added to a Celite-0.2N H2S04 column and the eluate is discarded. The alkaloids are then eluted from the column with ammoniacal CHCI3 and the eluate is evaporated to dryness. The residue is dissolved in CHC13, eosin Y solution is added, and the solution is mixed. Aliquots of a reference solution of atropine are similarly treated and a blank is prepared from CHCI3 and eosin Y solution. All solutions are scanned with a recording spectrofluorometer in the emission mode from 440 to 700 nm and the excitation set at 475 nm. The emission peaks near 550 nm are used for quantitative estimation of the alkaloids. The method cannot generally be used in the presence of other organic bases but is applicable in the presence of barbiturates.
Spectrophotometric Determination of Carboxin in Formulations After Extraction and Thin Layer Chromatographic Separation
Authors: Handa Swadesh K
Published: February 2020

Carboxin (5,6-dihydro-2-methyl-1,4-oxathiin-3-carboxanilide) is extracted from formulations with chloroform. The extract is subjected to thin layer chromatography and the carboxin zone is scraped from the developed plate. Carboxin is then eluted from the adsorbent with chloroform and determined spectrophotometrically at 300 nm. Recoveries from laboratory-prepared formulations were 97-98%.
Rapid Screening Method for Alkaline Phosphatase Activity in Cheese: Collaborative Study
Authors: Kleyn Dick H
Published: February 2020

The method developed for determining alkaline phosphatase activity in cheese, in which phenolphthalein monophosphate is used as the substrate, was collaboratively studied. A 7.5% butanol extract of cheese is reacted with phenolphthalein monophosphate; phenolphthalein is released and yields a red solution that is compared visually with a standard (s) prepared from the same extract. Seven collaborators analyzed 8 samples of cheese, in duplicate, by the screening method and Scharer I method. Of the 208 observations returned, only 4 were incorrect. The alkaline phosphatase method has been adopted as official first action.
Comparison of Sample Preparation Procedures for Colorimetric Analysis of Nitrite in Frankfurters
Authors: Nicholas Fiddler Rosemary , Fox Jay B
Published: February 2020

Three groups of methods for analyzing nitrite in meat are compared. All methods consist of a sequence of steps, grouped according to initial extraction procedures. In Croup 1, the sample is treated with borate followed by HgCl2 or Carrez I, and then Carrez II. In Group 2, the sample is diluted with water, heated at 80°C, and analyzed immediately (AOAC) or after addition of either Na2CO3 and FeCl3 or HgCl2. In Group 3, the sample is made alkaline with NH4C1 buffer and then treated with one of the following: activated carbon plus Carrez I and II, alumina cream, or A1K(S04)2. At each step when the method involved the addition of a chemical, supernates and precipitates (if formed) were analyzed for nitrite by Griess reagent both before and after AOAC digestion. The normally discarded precipitates formed after addition of HgCl2 and Carrez I and II contained bound nitrite that could be detected by AOAC analysis. Except in the AOAC method, HgCl2 improved nitrite analysis. Results by AOAC analysis were 3 to 300% higher than those determined after addition of any chemical or combination of chemicals. Spiked meat samples could not be used in comparing nitrite analysis methods because results were misleading. Acid meat samples, such as fermented sausages, required neutralization before AOAC analysis.
Liquid Chromatography with Fluorescence Detection of Lasalocid Sodium in Feeds and Premixes
Authors: Osadca Modest , Araujo Mercedes
Published: February 2020

Lasalocid sodium is extracted directly from feeds and premixes with the mobile phase solution, an aliquot is chromatographed, and the concentration (peak height) of lasalocid sodium is measured by high pressure liquid chromatography with fluorescence detection. Chromatography and detection are completed in about 7 min. The results agree well with those found by the official AOAC fluorometric method, 42.A08-42.A13. The method offers an alternative to the AOAC method and has the capability of processing almost twice as many samples. The average recovery of 4 levels (0.0008, 0.0040, 0.0080, and 0.0120%) of lasalocid sodium from feeds is 100%. Replicate assays of typical poultry mashes and pellets containing about 0.0080% lasalocid sodium yielded coefficients of variation of 2.68—3.35%.
Microbiological Method for Assaying Lincomycin in Animal Feed: Collaborative Study
Authors: Neff A William , Thomas Richard W
Published: February 2020

A microbiological assay for determining lincomycin in swine feed, supplement, and a vitamin- mineral premix was studied collaboratively in 16 laboratories. The design of the study involved a complete feed, feed supplement, and a vitamin-mineral premix covering a range of fortification from 20 to 80 g/ton and 80 to 2600 g/ton. Two methods of sample preparation were used depending on the concentration of lincomycin in the sample. Statistical evaluation of the results from the 2 methods indicated that 10 and 11 collaborators, respectively, had mean recoveries which were not significantly different from one another. Ten laboratories obtained a mean recovery of 112.2% (range 102.3-123.5%) for the lower level, and 11 laboratories obtained a mean recovery of 104.4% (range 100.0-107.7%) for the higher level. The method has been adopted as official first action.
Sodium Cobaltinitrite as a Reagent for Determining Some Phenolic Drugs
Authors: Wahbi Abdel-Aziz M , Abdine Hassan , Korany Mohamed , Abdel-Hay Mohamed H
Published: February 2020

Dichlorophen, oxyphenbutazone, phenazone, methyldopa, isoprenaline sulfate, and salbutamol sulfate are reacted with sodium cobaltinitrite in aqueous acetic acid. The yellow color is measured at 365, 320, 320, 330, 425, and 325 nm in aqueous acetic acid, respectively, and at 445, 380, 375, 345, 325, and 412 nm in sodium hydroxide, respectively. The reaction product is extractable with CHC13, with a maximum absorption at 370 nm for dichlorophen, 355 nm for phenazone, and 325 nm for oxyphenbutazone. The method is applied to the determination of these drugs in tablet form. The results obtained are reasonably reproducible with a coefficient of variation less than 2%.
Determination of Germanium, Arsenic, Tin, Selenium, and Antimony by Plasma Emission Spectrometry with Hydride Generation and Chromatographic Separation
Authors: Fricke Fred L , Robbins Wayne D , Caruso Joseph A
Published: February 2020

A semiautomated hydride generation device was coupled to a microwave-induced Ar/He plasma which is used with a 0.5 m monochromator. This coupling necessitated the use of a condensation tube and a Chromosorb 102 column to separate the analyte species from hydrogen produced during the generation reaction, and also to separate the analytes from condensed contaminants which cause spectral background interference. Data reported for Ge, As, Se, Sn, and Sb are detection limits in the ppb range and linear dynamic ranges which extend to 3 orders of magnitude. Precision of results ranges from 2.9 to 8.8%. Chromatographic characteristics of the elemental hydrides on 1, 3, and 6 ft columns are also reported. This system or portions of it can be used to substantially decrease both time and quantities of reagents needed for analysis in both simultaneous and sequential experiments in either emission spectroscopy or atomic absorption spectrometry.
Rapid Screening Field Test for Detecting Cadmium and Lead Extracted from Glazed Ceramic Dinnerware: Collaborative Study
Authors: Krinitz Benjamin
Published: February 2020

A test intended for field screening glazed ceramic dinnerware for acid-extractable cadmium and lead was subjected to collaborative study. The test, a modification of the classical dithizone procedure, requires no instrumentation. Ninety samples were field-tested for lead and then analyzed by the 24 hr official method; of 63 negative field tests, 48 had no lead after 24 hr, and each of the other 15 contained <0.7 ppm. Of 60 samples field tested for cadmium, 45 gave negative field tests; of these, 30 showed no cadmium by the 24 hr test, and 15 showed ≤0.09 ppm. All 15 laboratories participating in the study were able to detect a color change at 0.05 μg Cd and 0.3 μg Pb/ml 4% acetic acid. The method has been adopted as interim official first action.
Isomer Specific Assay of Ester and Salt Formulations of 2,4-Dichlorophenoxyacetic Acid by High Pressure Liquid Chromatography: Collaborative Study
Authors: Stevens Timothy S , Skelly Norman E , Grorud Robert B
Published: February 2020

A high pressure liquid chromatographic (HPLC) assay of ester and salt formulations of 2,4-D has been collaboratively studied. The method is specific for 2,4-D isomer and resolves all known impurities from 2,4-D and the internal standard p-bromophenol. In situ saponification, at room temperature, is performed by adding a combined saponification-internal standard solution to ester products. The same saponification- internal standard solution is added to amine salts and the analytical standard. The injected aqueous potassium salt solution of 2,4-D is then converted to the acid form by an acidic buffered mobile solvent of 20% acetonitrile in water. Optimum chromatography is attained by a mobile solvent pH of 2.95 in a reverse phase microparticulate column, by ion suppression. Each of the 9 collaborators received 3 different ester and 2 different amine formulations of 2,4-D. The coefficients of variation of 2,4-D acid equivalent ranged from 1.22 to 1.59%. The method has been adopted as official first action.