bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preliminary Collaborative Study of Modified Spectrophotometric Determination of Pyrantel Tartrate in Swine Feeds by the Method of Standard Additions
Authors: Litchman Mark A 
Published: February 2020

Abstract
A modified spectrophotometric method for determining pyrantel tartrate in swine feeds was subjected to a preliminary collaborative study. Two small-scale commercial pyrantel-medicated feed samples (0.0881 and 0.0106%) were assayed in replicate by 4 collaborators. The mean results of all laboratories were 0.0862 and 0.0112%. The mean coefficients of variation were 10.57 and 6.48%, respectively. Suggestions for improving recovery include the following: complete dissolution of standard, use of analytical grade KI, careful phase separation, thorough mixing, and minimum exposure of compound to light.
Extraction, Gas-Liquid Chromatographic Detection, and Quantitation of Hexachlorophene Residues from Plant Tissues High in Lipid Content
Authors: Van Auken Oscar W , Hulse Michael , Durocher Constance L 
Published: February 2020

Abstract
A method has been developed for the extraction, cleanup, derivatization, detection, and quantitation of hexachlorophene (HCP) residues from 2 types of plant storage tissue high in lipid content. Wet soybean or peanut tissue was homogenized and extracted with ethyl ether and chromatographed on silica gel to remove the neutral lipids. The cleaned up sample was methylated with diazomethane and the dimethoxyhexachlorophene was eluted from a second silica gel column and chromatographed on a 6′ glass column packed with 3% OV-1 or 3% SE-30 on Gas-Chrom Q. The instrument detection limit for the 63Ni electron capture detector was &lt;0.1 ng for dimethoxyhexachlorophene and about 1 ppb for HCP residue in plant issue. Recovery of 10–420 ppb HCP added to tissue averaged 90.9±5.7%. Interfering substances were removed, column life was increased, peak sharpness was increased, and tailing of the parent compound was decreased by using appropriate column chromatography.
Microbiological Plate and Turbidimetric Assays of Chlortetracycline in Feeds: Collaborative Study
Authors: Ragheb Hussein S 
Published: February 2020

Abstract
The manual and automated turbidimetric assays and a modified official plate assay for Chlortetracycline (CTC-HCl) in feed were collaboratively studied. Three feed samples (swine feed, 100 g CTC-HCl/ton; premix I, 20 g each of CTC-HCl and sulfamethazine/lb, and 10 g penicillin/lb; and premix II, 50 g CTC-HCl/lb) were analyzed at 2 dilutions. Twelve laboratories conducted the plate assay; 8 laboratories, the manual turbidimetric method ; and 7 laboratories, the Autoturb analysis. Within a method, there was no significant difference between dilutions. Between methods, there was a significant difference between the manual turbidimetric plate assays only for swine feed. However, the same sample dilutions or the average values of the 2 dilutions for both methods showed no statistical difference. Among the collaborators, the slope of CTC-HCl standard curve varied between about 2.0 and 3.0 for the plate method. The turbidimetric assay has been adopted as official first action for feeds containing &gt;20 g CTC-HCl/lb.
Atomic Absorption Spectroscopy of Copper and Iron in Plant Material
Authors: Boline Duane R , Schrenk W G 
Published: February 2020

Abstract
An atomic absorption spectroscopic (AAS) method is described for the determination of copper and iron by direct aspiration of a solution of an ashed sample in an alcohol-water mixture. The method has been applied to samples containing 2.0–31.9 μg Cu/g and 15.5–196 Fe/g. Operating conditions for using an acetylene-air flame have been established. The hollow cathode current needed to be carefully controlled for the copper analysis. No significant interference was noted from other elements commonly present in plants. Wet and dry ashing procedures provided comparable results. Recovery of added amounts of copper and iron ranged from 92 to 101% and 94 to 104%, respectively; most results were near 100%. The official AOAC colorimetric methods and the AAS method were compared and were comparable in reliability and accuracy. The AAS method is simpler and faster.
Analysis of Fat-Soluble Vitamins. XV. Confirmation of Isotachysterol in Vitamin D Concentrates
Authors: De Vries Ellen J , Mulder Frits J , Borsje Ben 
Published: February 2020

Abstract
The reaction with maleic anhydride yielding Diels-Alder adducts is used to distinguish vitamin D isomers. Treatment at 100°C for 3 hr eliminates the fast-reacting (tachysterol and trans-vitamin D) and slow-reacting (cis-vitamin D and previtamin D) isomers. However, isotachysterol is not eliminated. The procedure has been incorporated as a confirmation test for isotachy sterol in the official final action method for the determination of vitamin D in concentrates, 43.B14–43.B24.
High Pressure Liquid Chromatographic Determination of Vitamin D in Fortified Milk
Authors: Thompson James N , Maxwell William B , L’Abbé Mary 
Published: February 2020

Abstract
Vitamin D was determined in fortified milk by high pressure liquid chromatography (HPLC) after preliminary purification involving saponification at room temperature and low pressure chromatography on hydroxyalkoxypropyl Sephadex (HAPS). The saponified milk (50 ml) was extracted with ether, the extract was chromatographed in hexane on a 60 × 1 cm column of HAPS, and the absorption of the eluate at 254 nm was recorded. The fraction containing vitamin D was collected by using the position of characteristic peaks in the chromatogram as a guide. An aliquot of this fraction was chromatographed in an HPLC system on a 25 cm × 3.2 mm column of LiChrosorb Si 60 5 μm silicic acid, using 0.6% isopropanol in hexane (50% water-saturated) as the mobile phase. The absorption was set at 265 nm. Vitamin D was cleanly separated from other absorbing materials, and the amount could be calculated from the peak area. Recovery of added vitamin D was greater than 97 %.
Simplified Micro Perchlorination Method for Polychlorinated Biphenyls in Biological Samples
Authors: Crist Howard L , Moseman Robert F 
Published: February 2020

Abstract
Simplified methodology is presented for the micro determination of polychlorinated biphenyls (PCBs) in biological samples, by conversion to the decachlorobiphenyl (DCB) derivative. Beef adipose tissue and human milk extracts were fortified with PCB standards at 0.1–5.0 ppm, and perchlorinated with antimony pentachloride (SbCl5). Several Aroclors representing various degrees of chlorine content were investigated to assess the efficiency of conversion to DCB. Samples were cleaned up on a Florisil mini column and the PCBs were quantitated by electron capture GLC. Several chlorinated pesticides which were subjected to the perchlorination procedure did not interfere. As little as 0.1 ppm PCBs in 500 mg tissue extract can be recovered at 79–99%. The background DCB content of several brands of SbCl5 was determined. The levels of PCBs in human milk obtained by the perchlorination technique are compared with data acquired by electron capture gas-liquid chromatography in which the individual chlorobiphenyls in the sample are measured.
High Pressure Liquid Chromatographic Determination of Vitamin D3 in Livestock Feed Supplements
Authors: Ray Allen C , Dwyer J Nelson , Reagor John C 
Published: February 2020

Abstract
Vitamin D3 is determined in livestock feed supplements by high pressure liquid chromatography (HPLC). Extracts of the samples are quantitated using normal phase chromatography. If interfering co-extractives are present, an aliquot of the extract is injected on the normal phase column, and the fraction corresponding to vitamin D3 is collected. The vitamin fraction is then further cleaned up and separated from interferences by reverse phase chromatography, and quantitated by measuring the ultraviolet absorption at 254 and 280 nm. The method measures actual vitamin D3 content in the presence of pre-vitamin D, tachysterol, isotachysterol, and vitamin A.
Gas-Liquid Chromatographic Determination of Total Inorganic Iodine in Milk
Authors: Bakker Hendrik J 
Published: February 2020

Abstract
Total inorganic iodine in milk is determined by conversion to iodobutanone, which is quantitated by gas-liquid chromatography and electron capture detection. As little as 10 μg/L can be determined. The thyroid-active iodine content of milk can be determined rapidly with a relative standard deviation of 1.9%. Average recoveries for added iodide and iodine were 95.5 and 94.6%, respectively.
Gas-Liquid Chromatographic Determination of Isosorbide Dinitrate in Tablets
Authors: Prue David G , Johnson Raymond N , Kho Boen T 
Published: February 2020

Abstract
A gas-liquid chromatographic (GLC) method is described for determining isosorbide dinitrate (ISDN) in tablets. ISDN is extracted from tablet excipients by a 2-phase system composed of water-ethyl ether, and detected and quantitated with a flame ionization detector after separation from the internal standard (glyceryl tributyrate) on a 3% OV-210 column. Ten replicate assays on 2 different batches of tablets, each containing 5 mg ISDN, gave coefficients of variation of 1.16 and 1.48%, respectively. Comparison of results obtained for tablets containing 5, 10, and 40 mg ISDN, and for diluted isosorbide dinitrate raw material containing 25% ISDN, showed good correlation among the GLC, USP colorimetric, and USP polarographic procedures. Assay of synthetic mixtures containing ISDN, isosorbide-2-mononitrate, and isosorbide-5-mononitrate demonstrated that the GLC procedure is specific for ISDN, whereas the USP polarographic procedure is subject to interference from the mononitrates.
Atomic Absorption Spectrophotometric Determination of Lead, Cadmium, Zinc, and Copper in Clams and Oysters: Collaborative Study
Authors: Capar Stephen G 
Published: February 2020

Abstract
In the method studied, clams and oysters are dry ashed at 475°C, the ash is dissolved in dilute HNO3, and Pb, Cd, Zn, and Cu are determined by flame atomic absorption spectrophotometry (AAS). Sample solutions containing levels of Pb and Cd too low for direct AAS are extracted as the 1-pyrrolidinecarbodithioate complex into n-butyl acetate before AAS. The method was subjected to a collaborative study to determine the precision and accuracy of the analysis. Concentration ranges in the samples studied were approximately 0.06–2 ppm Pb, 0.03–2 ppm Cd, 40–600 ppm Zn, and 5–50 ppm Cu. Within these ranges, Cd levels &lt;0.5 ppm and Pb at all levels required extraction prior to AAS. The average coefficients of variation for Pb, Cd, Zn, and Cu were, respectively, 66.0, 93.2, 8.5, and 20.5% for the lowest levels and 13.5, 3.8, 6.7, and 6.8% for the highest levels. Recoveries were computed by using the sum of the average collaborative results for the totally unfortified samples plus the fortification levels as the expected concentration. The average recoveries of Pb, Cd, Zn, and Cu were, respectively, 94.0, 99.7, 99.3, and 100.2 % for the lowest fortification level and 94.8, 95.6, 96.5, and 97.5% for the highest level. High levels of Cu and/or Zn caused incomplete extraction of Pb and Cd, with Cd being affected more severely than Pb. Data obtained also suggest that background corrections may be needed for determining Zn and Cd with the direct aspiration technique. No recommendation is made for official action.
Internal Carotid Artery Dissection Presenting as Partial Horner’s Syndrome and Vertigo
Authors: Teixeira Jeffrey C , Jackson Paula J 
Published: February 2020

Abstract
Distinguishing between central and peripheral causes of vertigo can be challenging not only in an acute setting but also in chronic settings. A thorough review of systems and physical exam can assist providers in differentiating central versus peripheral etiologies and the need for urgent imaging. In this case, a 47-year-old man presented with vertigo, right-sided hearing loss, right-sided headache, and right-sided facial pain that began 4 weeks before while the patient was on a cruise ship. His physical exam findings were notable for anisocoria with right pupil 3.5 and left pupil 4.5, mild ptosis on the right side, positive Romberg test to the right, and Fakuda test with deviation to the right. Urgent magnetic resonance imaging revealed dissection of the right cervical internal carotid artery with a nonocclusive intramural hematoma. This case illustrates the importance of imaging in vertigo patients in which a central etiology is suspected. It further demonstrates that isolated partial Horner’s or unilateral headache may indeed be the only presenting sign in a carotid dissection.
Tiers for Education and Training in Global Health for Military Engagement
Authors: Burkett Edwin K , Aguirre Diana L 
Published: February 2020

Abstract
This article describes four tiers for knowledge required by U.S. military personnel to effectively execute global health activities. Department of Defense policy does not identify a formal global health education path for personnel responsible for global health activities. Department of Defense must implement formal education programs to improve mission success and favorable health outcomes.
The screening of blood by Aspergillus PCR and galactomannan ELISA precedes BAL detection in patients with proven and probable IA
Authors: Springer Jan , Löffler Jürgen , Einsele Hermann , White P Lewis 
Published: February 2020

AbstractEarly detection of Aspergillus infection has the potential to facilitate a more effective management of invasive disease. Data from probable/proven cases of invasive aspergillosis (IA) with a positive galactomannan enzyme-linked immunosorbent assay (GM) bronchoalveolar lavage fluid (BALF) was analyzed in respect to serum GM and/or polymerase chain reaction (PCR) screening of blood samples prior to, or concurrent with bronchoscopy. Concurrent serum GM testing is less sensitive than BALF itself. Nevertheless screening of blood using GM or PCR testing detected IA cases earlier (GM: 42% or PCR: 56%), particularly when combined (GM/PCR: 73%). Therefore, regular screening facilitates and improves early detection of IA in patients suffering from acute leukemia.
Maser flares driven by variations in pumping and background radiation
Authors: Gray M D , Etoka S , Travis A , Pimpanuwat B 
Published: February 2020

ABSTRACT
We simulate maser flares by varying either the pump rate or the background level of radiation in a 3D model of a maser cloud. We investigate the effect of different cloud shapes, saturation levels, and viewpoints. Results are considered for clouds with both uniform and internally variable unsaturated inversion. Pumping and background variations are represented by several different driving functions, some of which are light curves drawn from observations. We summarize the pumping variability results in terms of three observable parameters: the maximum flux density achieved, a variability index, and duty cycle. We demonstrate typical ranges of the flux density that may result from viewing an aspherical object from random viewpoints. The best object for a flare is a prolate cloud, viewed close to its long axis and driven from unsaturated conditions to at least modest saturation. Results for variation of the background level are qualitatively different from the variable pumping results in that they tend to produce short intervals of low flux density under conditions of moderate saturation and sufficient variability to be consistent with strong flaring. Variable background models typically have a significantly higher duty cycle than those with variable pumping.
Molecular cloud formation by compression of magnetized turbulent gas subjected to radiative cooling
Authors: Mandal Ankush , Federrath Christoph , Körtgen Bastian 
Published: February 2020

ABSTRACT
Complex turbulent motions of magnetized gas are ubiquitous in the interstellar medium (ISM). The source of this turbulence, however, is still poorly understood. Previous work suggests that compression caused by supernova shockwaves, gravity, or cloud collisions, may drive the turbulence to some extent. In this work, we present three-dimensional (3D) magnetohydrodynamic (MHD) simulations of contraction in turbulent, magnetized clouds from the warm neutral medium of the ISM to the formation of cold dense molecular clouds, including radiative heating and cooling. We study different contraction rates and find that observed molecular cloud properties, such as the temperature, density, Mach number, and magnetic field strength, and their respective scaling relations, are best reproduced when the contraction rate equals the turbulent turnover rate. In contrast, if the contraction rate is significantly larger (smaller) than the turnover rate, the compression drives too much (too little) turbulence, producing unrealistic cloud properties. We find that the density probability distribution function evolves from a double lognormal representing the two-phase ISM, to a skewed, single lognormal in the dense, cold phase. For purely hydrodynamical simulations, we find that the effective driving parameter of contracting cloud turbulence is natural to mildly compressive (b ∼ 0.4–0.5), while for MHD turbulence, we find b ∼ 0.3–0.4, i.e. solenoidal to naturally mixed. Overall, the physical properties of the simulated clouds that contract at a rate equal to the turbulent turnover rate, indicate that large-scale contraction may explain the origin and evolution of turbulence in the ISM.
Locations of optical and γ-ray emitting regions and variation phenomena of PMN J2345−1555
Authors: Jiang Yunguo , Hu Shao-Ming , Chen Xu , Shao Xi , Huo Qiu-Hong 
Published: February 2020

ABSTRACT
We collect the long-term γ-ray, optical, and radio 15 GHz light curves of quasar object PMN J2345−1555, and make correlation analyses between them. We find that different samplings can lead to different time delays, and the periodicity of light curves can produce signals that are beyond 3σ significance level. The optical V and R band and the infrared J band light curves lead the radio 15 GHz light curve by $49^{+15}_{-12}$ d. There is no lag between the optical and γ-ray light curves. We use the time lags to derive the core size and its uncertainty. We find that the core region of 15 GHz is $1.5^{+0.4}_{-0.5}$ parsec away from the jet base. The optical and γ-ray emitting regions coincide, which are located at $1.0^{+0.3}_{-0.2}$ parsec upstream of the core region of 15 GHz. Thus, the optical and γ-ray emitting regions are most probably inside the broad-line region. For this target, the magnetic field and particle density at 1 parsec in the jet are derived to be 0.16 G and 247/γmin cm−3, respectively. The black hole mass is estimated to be 108.44 M⊙. The behaviour of δV − δR is complex, while the R − J shows a bluer-when-brighter trend. We proposed an r-dependent spectral index model to explain the colour index behaviours, which is complementary for the shock in jet model. The possibility that the spectral index behaviours are due to the contribution from the disc and the varying Doppler factor is not excluded.
Triggering mixing and deceleration in FRI jets: a solution
Authors: Perucho Manel 
Published: February 2020

ABSTRACT
Since Fanaroff & Riley reported the morphological and brightness dichotomy of radio galaxies, and it became clear that the symmetric emission from jets and counter-jets in the centre-brightened, less powerful, FRI sources could be caused by jet deceleration, many works have addressed different mechanisms that could cause this difference. Recent observational results seem to indicate that the deceleration must be caused by the development of small-scale instabilities that force mixing at the jet boundary. According to these results, the mixing layer expands and propagates down to the jet axis along several kiloparsecs, until it covers the whole jet cross-section. Several candidate mechanisms have been proposed as the initial trigger for the generation of such mixing layer. However, the instabilities proposed so far do not fully manage to explain the observations of FRI jets and/or require a triggering mechanism. Therefore, there is not still a satisfactory explanation for the original cause of jet deceleration. In this letter, I show that the penetration (and exit) of stars from jets could give the adequate explanation by means of creating a jet-interstellar medium mixing layer that expands across the jet.
Low Uptake of Rapid Diagnostic Tests for Respiratory Tract Infections in an Urban Safety Net Hospital
Authors: Burrowes Shana A B , Rader Alec , Ni Pengsheng , Drainoni Mari-Lynn , Barlam Tamar F 
Published: February 2020

Abstract

Background
Rapid diagnostic tests (RDTs) have been developed with the aim of providing accurate results in a timely manner. Despite this, studies report that provider uptake remains low.

Methods
We conducted a retrospective analysis of ambulatory, urgent care, and emergency department (ED) encounters at an urban safety net hospital with a primary diagnosis of an upper or lower respiratory tract infection (eg, bronchitis, pharyngitis, acute sinusitis) from January 1, 2016, to December 31, 2018. We collected RDT type and results, antibiotics prescribed, demographic and clinical patient information, and provider demographics.

Results
RDT use was low; a test was performed at 29.5% of the 33 494 visits. The RDT most often ordered was the rapid Group A Streptococcus (GAS) test (n = 7352), predominantly for visits with a discharge diagnosis of pharyngitis (n = 5818). Though antibiotic prescription was more likely if the test was positive (relative risk [RR], 1.68; 95% confidence interval [CI], 1.58–1.8), 92.46% of streptococcal pharyngitis cases with a negative test were prescribed an antibiotic. The Comprehensive Respiratory Panel (CRP) was ordered in 2498 visits; influenza was the most commonly detected pathogen. Physicians in the ED were most likely to order a CRP. Antibiotic prescription was lower if the CRP was not ordered compared with a negative CRP result (RR, 0.77; 95% CI, 0.7–0.84). There was no difference in prescribing by CRP result (negative vs positive).

Conclusions
RDTs are used infrequently in the outpatient setting, and impact on prescribing was inconsistent. Further work is needed to determine barriers to RDT use and to address potential solutions.
FOREST unbiased Galactic plane imaging survey with the Nobeyama 45 m telescope (FUGIN). VI. Dense gas and mini-starbursts in the W 43 giant molecular cloud complex
Authors: Kohno Mikito , Tachihara Kengo , Torii Kazufumi , Fujita Shinji , Nishimura Atsushi , Kuno Nario , Umemoto Tomofumi , Minamidani Tetsuhiro , Matsuo Mitsuhiro , Kiridoshi Ryosuke , Tokuda Kazuki , Hanaoka Misaki , Tsuda Yuya , Kuriki Mika , Ohama Akio , Sano Hidetoshi , Hasegawa Tetsuo , Sofue Yoshiaki , Habe Asao , Onishi Toshikazu , Fukui Yasuo 
Published: February 2020

AbstractWe performed new large-scale 12CO, 13CO, and C18O J = 1–0 observations of the W 43 giant molecular cloud complex in the tangential direction of the Scutum arm (l ∼30°) as a part of the FUGIN project. The low-density gas traced by 12CO is distributed over 150 pc × 100 pc (l × b), and has a large velocity dispersion (20–30 km s−1). However, the dense gas traced by C18O is localized in the W 43 Main, G30.5, and W 43 South (G29.96−0.02) high-mass star-forming regions in the W 43 giant molecular cloud (GMC) complex, which have clumpy structures. We found at least two clouds with a velocity difference of ∼10–20 km s−1, both of which are likely to be physically associated with these high-mass star-forming regions based on the results of high 13CO J = 3–2 to J = 1–0 intensity ratio and morphological correspondence with the infrared dust emission. The velocity separation of these clouds in W 43 Main, G30.5, and W 43 South is too large for each cloud to be gravitationally bound. We also revealed that the dense gas in the W 43 GMC has a high local column density, while “the current SFE” (star formation efficiency) of the entire GMC is low ($\sim\!\! 4\%$) compared with the W 51 and M 17 GMC. We argue that the supersonic cloud–cloud collision hypothesis can explain the origin of the local mini-starbursts and dense gas formation in the W 43 GMC complex.