bluuebunny/crossref_metadata_2025 huggingface dataset:
The optical properties of the Woodburytype—an alternative printing technique based on a gelatine/pigment matrix
Authors: Leech D J , Guy W , Klein S
Published: January 2020

The Woodburytype is a 19th century photomechanical printing method, producing high-quality continuous-tone images that use a suspension of carbon black in gelatine as a relief print, in which the variation in height of the print produces the grayscale and contrast. We propose a phenomenological optical model for the process based on Kubelka-Munk theory that considers the ink formulation, the print height and the substrate surface in order to provide the ideal combination of printing depth and contrast.
Sets of universal sequences for the symmetric group and analogous semigroups
Authors: Hyde J. , Jonušas J. , Mitchell J. , Péresse Y.
Published: January 2020

Auniversal sequencefor a group or semigroupSSis a sequence of wordsw1,w2,…w_1, w_2, \ldotssuch that for any sequences1,s2,…∈Ss_1, s_2, \ldots \in S, the equationswn=snw_n = s_n,n∈Nn\in \mathbb {N}, can be solved simultaneously inSS. For example, Galvin showed that the sequence<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="left-parenthesis a Superscript negative 1 Baseline left-parenthesis a Superscript n Baseline b a Superscript negative n Baseline right-parenthesis b Superscript negative 1 Baseline left-parenthesis a Superscript n Baseline b Superscript negative 1 Baseline a Superscript negative n Baseline right-parenthesis b a right-parenthesis Subscript n element-of double-struck upper N">(a−1(anba−n)b−1(anb−1a−n)ba)n∈N(a^{-1}(a^nba^{-n})b^{-1}(a^nb^{-1}a^{-n})ba)_{n\in \mathbb {N}}is universal for the symmetric groupSym⁡(X)\operatorname {Sym}(X)whenXXis infinite, and Sierpiński showed that(a2b3(abab3)n+1ab2ab3)n∈N(a ^2 b ^3 (abab ^3) ^{n + 1} ab ^2 ab ^3)_{n\in \mathbb {N}}is universal for the monoidXXX ^Xof functions from the infinite setXXto itself.

In this paper, we show that under some conditions, the set of universal sequences for the symmetric group on an infinite setXXis independent of the cardinality ofXX. More precisely, we show that ifYYis any set such that|Y|≥|X||Y| \geq |X|, then every universal sequence forSym⁡(X)\operatorname {Sym}(X)is also universal forSym⁡(Y)\operatorname {Sym}(Y). If|X|>2ℵ0|X| > 2 ^{\aleph _0}, then the converse also holds. It is shown that an analogue of this theorem holds in the context of inverse semigroups, where the role of the symmetric group is played by the symmetric inverse monoid. In the general context of semigroups, the full transformation monoidXXX ^Xis the natural analogue of the symmetric group and the symmetric inverse monoid. IfXXandYYare arbitrary infinite sets, then it is an open question as to whether or not every sequence that is universal forXXX ^Xis also universal forYYY ^Y. However, we obtain a sufficient condition for a sequence to be universal forXXX ^Xwhich does not depend on the cardinality ofXX. A large class of sequences satisfies this condition, and hence is universal forXXX ^Xfor every infinite setXX.
1. Drinking and temperance
Authors: Rorabaugh W. J.
Published: January 2020

‘Drinking and temperance’ describes the history of alcohol consumption in the United States and the introduction of the temperance movement. From the earliest European settlers to the fighters of the Revolution, Americans were among the world’s heartiest drinkers, producing their own corn beer and importing rum from the West Indies. The British blockades during the war meant access to rum was lost. Americans began to distill whiskey from corn instead, which became the country’s patriotic drink. Problems associated with heavy drinking resulted in reformers creating the temperance movement, a cause that was then taken up by Protestant preachers. In the 1850s, evangelicals lobbied for statewide prohibition laws, but there was no viable system of enforcement.
2. The dry crusade
Authors: Rorabaugh W. J.
Published: January 2020

‘The dry crusade’ describes the increasing number of anti-liquor reformers who wanted state and national prohibition. Key groups were the Women’s Crusade and Woman’s Christian Temperance Union of Ohio and the Anti-Saloon League. Middle-class women dried up dozens of small towns, but when anti-liquor reformers in larger towns led similar movements, they met defiance and resistance. The rise of local option in the 1880s and 1890s meant smaller communities could support a ban even if votes were lacking to prohibit alcohol statewide. Without World War I, it is doubtful that prohibition would ever have passed Congress or been ratified, but enforcement turned out to be far more challenging than the dry forces ever imagined.
5. Legacies
Authors: Rorabaugh W. J.
Published: January 2020

‘Legacies’ explains that the most important legacy of prohibition in the United States concerned a dramatic change in drinking habits. The raunchy all-male saloon disappeared for good and per capita consumption of alcohol was reduced for a very long time. Consumption in the 1930s was one-third lower than before prohibition because people had little money to spend on drinks during the Great Depression and because a generation that had come of age during prohibition never imbibed much alcohol. Other legacies include industry-sponsored scientific research on alcohol and alcoholism; the founding of Alcoholics Anonymous, which placed responsibility for drinking upon the individual drinker; and the 1980s designated driver scheme proposed by Mothers Against Drunk Driving.
Introduction
Authors: Guelzo Allen C.
Published: January 2020

The Reconstruction era embraces the twelve years, from 1865 to 1877, of active effort to rebuild and reconstitute the American union after the attempt by the Confederate States of America to secede from it. The Introduction explains how it left a long legacy of bitterness, especially among Southerners who believed that they had fought an honorable war and were handed a dishonorable peace. Reconstruction also coincided with an eruption of unprecedented levels of graft, corruption, and fraud in American civil governments. But Reconstruction is probably best known, and least liked, for its failure to erase the treacherous impact of slavery and race in a reconstructed and unified nation.
1. Vengeance: April–December 1865
Authors: Guelzo Allen C.
Published: January 2020

‘Vengeance, April–December 1865’ begins with the death of Abraham Lincoln on April 15, 1865, after being shot by the Southerner, John Wilkes Booth, and the swearing in of Lincoln’s vice president, Andrew Johnson, as the seventeenth president. Johnson promised to deal harshly with the guilty Confederacy, but how this was to be translated into policy was another question. Reconstruction of the Union would require dealing with a thorny hedge of legal, constitutional, and political questions. Initially, Johnson had to concentrate his attention on ending the war. His early hard line was soon replaced with a softened approach to the Southern states, much to the anger of the Republicans of the North.
2. Alienation: December 1865–March 1867
Authors: Guelzo Allen C.
Published: January 2020

The Radical Republicans arrived in Washington for the opening of Congress on December 4, 1865 with two major weapons in their hands: one was the party caucus and the other was the lopsided majorities Republicans had won in the House and Senate. ‘Alienation, December 1865–1867’ outlines how the Republican juggernaut would produce, over the next seven months, a flurry of legislation, speeches, and reports designed to dissolve the self-reconstructed governments, extend voting rights to the freedmen by national authority, and reach over Johnson’s hands to seize the reins of Reconstruction for Congress. Despite Johnson vetoing legislation, Congress over-rode these vetoes; presidential-style reconstruction was dead.
4. Resistance: May 1868– March 1869
Authors: Guelzo Allen C.
Published: January 2020

1868 should have been the high mark of achievement for Reconstruction, but, in hindsight, it all happened too fast. ‘Resistance, May 1868–March 1869’ describes how between the Reconstruction acts and the re-admission of the first seven Southern states, voter registration was carried-out, the old Confederate power structure dismantled or disabled, state constitutional conventions called and constitutions written, and elections held for both state and federal legislatures, not to mention a presidential election, which was won by the Republican Ulysses S. Grant. With over half a million paroled Confederate veterans, mostly unemployed and smoldering with resentments, large pools of clandestine white resistance easily sprang to life, the most infamous of these being the Ku Klux Klan.
5. Distraction: March 1869– May 1872
Authors: Guelzo Allen C.
Published: January 2020

‘Distraction, March 1869–May 1872’ describes the early part of the presidency of Ulysses S. Grant and the rise of anti-Republican resistance. Instead of signaling caution, Grant proposed to move ahead as swiftly as possible to restore the remaining Southern states: Virginia, Mississippi, Texas, and Georgia. This should have marked the conclusion of Reconstruction, except that the Republican governments in the Southern statehouses were fragile and unstable, and led by political non-entities willing to take off in any direction that would ensure some kind of permanence in office-holding. The Republican South was economically shaky and the Grant administration also struggled with negotiations with the native Indian tribes.
5. Medieval interactions (700–1500)
Authors: Cohen Charles L.
Published: January 2020

“Medieval interactions (700–1500)” considers the relationships among Jews, Christians, and Muslims between 700 and 1500 ce. Islam’s close association with the state influenced the development of its theology and law, the leading discipline for ordering Islamic societies and for framing Muslims’ interactions with Christians and Jews. The association of both Christianity and Islam with state power encouraged ideologies that could justify military action against the other, most notably the Crusades. Religious minorities—Jews and Christians in Muslim lands; Jews and Muslims in Christian territory—often lived restricted lives, yet Christian and especially Muslim practice sometimes allowed for toleration as well as extensive cultural and intellectual exchange, albeit without ceding political control.
1. The origins of superstition
Authors: Vyse Stuart
Published: January 2020

‘The origins of superstition’ describes practices of magic, prophecy, and divination in the ancient world, and the changing meaning of superstition through time. Throughout its long history, superstition has been a transactional concept with no fixed meaning of its own except in contrast to some other, more accepted world-view. The origin of the concept is found in ancient Greece in the 4th century bce, and for the next 2,000 years, superstition stood in contrast to the religious practices recommended by the elites. The word ‘superstition’ has often been levelled at practices that, even today, we would consider magical or paranormal, and yet versions of most of these practices are still with us.
4. Enthusiastic resignation
Authors: Heilbron J. L.
Published: January 2020

‘Enthusiastic resignation’ describes Bohr’s work with Wolfgang Pauli and Werner Heisenberg. ‘Resignation’ refers to their realization that the electron orbits that had served as the basis of Bohr’s theory had only ‘symbolic’ value. They took the correspondence principle as a guide to translating symbols describing the orbits, like position and momentum, into symbols specifying the values of observable products of atoms, like the frequency and intensity of spectral lines. Heisenberg’s breakthrough in the summer of 1925, based on a particulate view of matter, provided a basis for a coherent description of the phenomena to which atomic electrons give rise. Almost simultaneously, Erwin Schrödinger found another route to the same mathematical solution, based on a wave picture of matter, which avoided discontinuity and made calculations easier. In answering Schrödinger’s challenge, Heisenberg invented the Uncertainty Principle and Bohr worked out a more general reconciliation of the quantum puzzles, which he called ‘complementarity’.
1. Creating a peninsular kingdom
Authors: Seth Michael J.
Published: January 2020

‘Creating a peninsular kingdom’ describes the early Korean societies and tribal peoples that gradually coalesced into states. Much of Korea’s pre-modern history was shaped by its interaction with China. Following the decline of the Chinese Empire by the 4th century ce, three indigenous states—Koguryǒ, Paekche, and Silla—emerged that dominated Korea from the 4th to the 7th century, fighting each other for supremacy. Wang Kǒn ended up the victor, putting together a reunified state under Koryǒ. His dynasty ruled Korea for more than four and a half centuries. The following Mongol period is then described, which contributed to a Korean cultural and ethnic identity and made the society more cosmopolitan.
5. Competing states, diverging societies
Authors: Seth Michael J.
Published: January 2020

By 1953 almost all Koreans had accepted that they belonged to a single nation united by blood, culture, history, and destiny. However, the end of the Korean War left them divided into two states. ‘Competing states, diverging societies’ explains that each state shared the same goal of creating a prosperous, modern, unified Korean nation-state that would be politically autonomous and internationally respected. The leadership of each saw the division as temporary and themselves and the state they governed as the true representative of the aspirations of the Korean people, and the legitimate successor to the pre-colonial state. While sharing many of the same goals they followed very different paths to reach them and became ever more divergent societies.
Dietary vitamin D in female rock lizards induces condition-transfer effects in their offspring
Authors: Rodríguez-Ruiz Gonzalo , López Pilar , Martín José
Published: January 2020

One way that maternal effects may benefit the offspring is by informing them about the characteristics of the environment. Through gestation, environmentally induced maternal effects might promote in the offspring-specific behavioral responses like dispersal or residence according to their new habitat characteristics. Females of the Carpetan rock lizard (Iberolacerta cyreni) seem to choose their home ranges using the smell of provitamin D3 in scent marks produced by males. Here, we supplemented gravid females of I. cyreni with dietary provitamin D3 or vitamin D3 to examine whether these food resources, also associated with the scent of males, affect the motivation to disperse and the locomotor performance of their offspring. Our results suggest that the supplementary availability of the resource (vitamin D3) to mothers may provoke condition-transfer maternal effects that motivate the residence or the dispersal of the offspring in their postnatal habitat. Thus, hatchlings of supplemented females had a lower dispersal trend in spite of having a greater climbing ability than hatchlings from nonsupplemented females. This suggests that the levels of provitamin D3 and vitamin D3 inside the body of the mother could act as an informative compound of the habitat quality for the offspring.
Toward a high-quality pan-genome landscape ofBacillus subtilisby removal of confounding strains
Authors: Wu Hao , Wang Dan , Gao Feng
Published: January 2020

Pan-genome analysis is widely used to study the evolution and genetic diversity of species, particularly in bacteria. However, the impact of strain selection on the outcome of pan-genome analysis is poorly understood. Furthermore, a standard protocol to ensure high-quality pan-genome results is lacking. In this study, we carried out a series of pan-genome analyses of different strain sets of Bacillus subtilis to understand the impact of various strains on the performance and output quality of pan-genome analyses. Consequently, we found that the results obtained by pan-genome analyses of B. subtilis can be influenced by the inclusion of incorrectly classified Bacillus subspecies strains, phylogenetically distinct strains, engineered genome-reduced strains, chimeric strains, strains with a large number of unique genes or a large proportion of pseudogenes, and multiple clonal strains. Since the presence of these confounding strains can seriously affect the quality and true landscape of the pan-genome, we should remove these deviations in the process of pan-genome analyses. Our study provides new insights into the removal of biases from confounding strains in pan-genome analyses at the beginning of data processing, which enables the achievement of a closer representation of a high-quality pan-genome landscape of B. subtilis that better reflects the performance and credibility of the B. subtilis pan-genome. This procedure could be added as an important quality control step in pan-genome analyses for improving the efficiency of analyses, and ultimately contributing to a better understanding of genome function, evolution and genome-reduction strategies for B. subtilis in the future.
A Domain-General Cognitive Core Defined in Multimodally Parcellated Human Cortex
Authors: Assem Moataz , Glasser Matthew F , Van Essen David C , Duncan John
Published: January 2020

Numerous brain imaging studies identified a domain-general or “multiple-demand” (MD) activation pattern accompanying many tasks and may play a core role in cognitive control. Though this finding is well established, the limited spatial localization provided by traditional imaging methods precluded a consensus regarding the precise anatomy, functional differentiation, and connectivity of the MD system. To address these limitations, we used data from 449 subjects from the Human Connectome Project, with the cortex of each individual parcellated using neurobiologically grounded multimodal MRI features. The conjunction of three cognitive contrasts reveals a core of 10 widely distributed MD parcels per hemisphere that are most strongly activated and functionally interconnected, surrounded by a penumbra of 17 additional areas. Outside cerebral cortex, MD activation is most prominent in the caudate and cerebellum. Comparison with canonical resting-state networks shows MD regions concentrated in the fronto-parietal network but also engaging three other networks. MD activations show modest relative task preferences accompanying strong co-recruitment. With distributed anatomical organization, mosaic functional preferences, and strong interconnectivity, we suggest MD regions are well positioned to integrate and assemble the diverse components of cognitive operations. Our precise delineation of MD regions provides a basis for refined analyses of their functions.
Clinical Significance of the Magnesium : Calcium Ratio
Authors: Friedman Howard S , Rubin Martin A
Published: January 2020

1. The Schwartzenbach method has been adapted for the simultaneous determination of calcium and magnesium in serum and spinal fluid. The method appears to be adaptable to all body fluids, including thoracic and abdominal transudates and exudates. Its use in the clinical laboratory is recommended because of the great saving of time, particularly in the determination of magnesium.

2. A series of 100 pathologic cases of various clinical entities has been analyzed by the new method and checked with the standard methods. A calculation and statistical analysis has revealed the Mg/Ca molar ratio to be of possible clinical significance.
Estimation of Hydrocortisone Secretion
Authors: Silber Robert H
Published: January 2020

A method has been described for the estimation of the secretion of hydrocortisone by the adrenals of man, based exclusively upon urinary-excretion data. In an 8-hour period (8:30 A.M.-4:30 P.M.)5 subjects secreted an average of 13.8 mg. of hydrocortisone. In 1 subject ACTH was found to increase the adrenal output whereas aspirin, ascorbic acid, and Pyribenzamine had little, if any, effect.

The possible application of the approach to the measurement of the formation of other substances in the body has been noted.
Quantitative Identification of Urinary Calculi
Authors: Leonard Reid H , Butt Arthur J
Published: January 2020

Quantitative determination of calcium, phosphorus, and oxalic acid, assisted by occasional determination of ammonia nitrogen and insoluble nitrogen when indicated by qualitative tests, provides a means of computing the component substances of calculi. The determinations may be performed by slight modifications of the methods in use in the routine clinical chemistry laboratory, although flame photometry is particularly convenient for the determination of calcium.
A Note on Quantitative Urobilinogen Determinations
Authors: Balikov Bernard
Published: January 2020

A procedure has been discussed whereby the optimum extraction of urobilinogen from feces and urine can be accomplished by standardization of acidulation of the ferrous hydroxide filtrates in the Watson method.
The Correspondence with Beer's Law for the Optical Density of Stained Protein Patterns on Filter Paper as a Function of Surface Protein Concentration
Authors: Rees V H , Laurence D J R
Published: January 2020

The results obtained here consistently failed to show deviations from Beer's law for optical densities less than 1.4, and the use of scanning as a convenient method for differential protein estimations would appear to be justified. The methods described may enable other workers to make similar tests of the method with a minimum of preliminary development, and some may succeed in obtaining significant failure of Beer's law in their apparatus. The use of apparatus of this type would enable the variation of the deviations with arrangement of the optical system, etc., to be worked out, but the following experimental conditions are already known to lead to significant deviations:

1. Use of dry paper instead of lightly oiled paper.

2. An inadequate light ifiter for the photocell.

3. An illuminated slit too long to be completely covered by the protein pattern.

4. Variations in protein density over the slit, either because the slit is too wide or because the protein pattern has been applied unevenly.

5. Use of low quality ifiter paper containing "pin holes."

6. A dye uptake which is not proportional to protein content of the paper [Martin and Franglen (14)].

The failure of Crook, Harris, and Warren (4) to substantiate Beer's law does not indicate the most general situation for the application of the scanning method.

The application of Beer's logarithmic law to the scanning of dyed protein patterns has been investigated by methods described in detail. No deviations could be found for optical densities less than 1.4 for amidoschwarz 1OB or less than 1.1 for azocarmine B staining. The scanning method can be used for evaluation of protein fractions if care is taken.
Commonly Used Medications that Interfere with Routine Endocrine Laboratory Procedures
Authors: Borushek Samuel , Gold Jay J
Published: January 2020

Ten groups of commonly utilized medications were examined both in vitro and in vivo for their ability to interfere with optical density measurement and/or color development in such routine endocrine laboratory tests as those for 17-ketosteroids and 17-hydroxycorticosteroids. Certain antihypertensives, tranquilizers, psychic energizers, monoamine oxidase inhibitors, and soporifics were found to create the most problems in interference. The importance of removing these medications from the patients' therapeutic regimes prior to obtaining specimens for such endocrine procedures is stressed.
Analysis on Heat Coagulated Blood and Serum
Authors: London Morris , Marymont Jesse H
Published: January 2020

A method for the determination of serum glucose employing a heat clot technic for the elimination of protein and other interfering substances is described. Serum (0.10 ml.) and absolute methyl alcohol (0.09 ml. delivered as six drops) are mixed in a shell vial and a clot is formed by immersion of the vial in a 60° water bath for 4 min. The clot is overlaid with 2.0 ml. of water and the container is placed in a 37° water bath for 45 min.; 0.50 ml. of the extract is added to 6.0 ml. of a glucose oxidase reagent and the solution placed in a 37° water bath for 30 min. Two drops of 4N HCI is added and the absorbance at 420 mµ measured. The serum glucose is calculated in the usual manner by comparing the absorbance of the unknown with that of a standard. The method is simple, reliable, and well suited for routine use in the clinical laboratory.
The Photometric Microdetermination of Tryptophan in Biologic Materials
Authors: Saifer Abraham , Gerstenfeld Shirley
Published: January 2020

A modification of the Fischl (6) glyoxylic acid method for tryptophan was developed which permits the reaction to occur quantitatively in aqueous solution by substitution of 70% HCIO4 (w/v) for concentrated H2S04. Spectral analysis of the chromogen formed showed a strong adsorption band at 365 mµ for pure tryptophan which was 17 times more sensitive than that at 560 mµ. Factors were studied which influence the absorbance of the tryptophan chromogen at 365 mµ and the most favorable conditions for its formation.

A new method for hydrolyzing proteins and peptides was evolved using 3.5% HCIO4 (w/v) which results in complete rupture of the peptide bond while retaining intact the indole nucleus. Application of the modified glyoxylic acid method to perchloric acid hydrolyzates of various proteins and peptides of known tryptophan content gave experimental values in close agreement with those calculated from the structural formulae. The over-all reproducibility of the procedure for separate hydrolyzates, run in duplicate, of the same protein or peptide sample was about ±3.0%.

Comparison of the tryptophan values obtained for 19 different "purified" peptides and proteins checked rather well with some of the results reported in the literature for the same materials using other procedures, except for trypsin and ovomucoid.
Simplified Estimation of Leucine Aminopeptidase (LAP) Activity
Authors: Martinek Robert G , Berger Louis , Broida Dan
Published: January 2020

An accepted colorimetric assay for the end product of the enzymic hydrolysis of L-leucyl-β-naphthylamide by leucine aminopeptidase in serum and urine has been modified. This modification has been shown to result in enhanced facility of handling large numbers of assays of this enzyme with considerably improved precision.
An Evaluation of Serum Protein Fractionation Using a Methyl Orange Method for Determination of Albumin
Authors: Crowley Leonard V
Published: January 2020

Fractionations of serum proteins using dye-binding methods have become popular because such methods are simple and can be adapted easily to automated systems of analysis, and the results of analysis performed on normal serums correlate well with results obtained by other methods. However, the good correlations do not necessarily apply when dealing with abnormal serums. Analysis of a selected group of serums revealed in 14% of cases a relatively poor correlation between fractionation by electrophoresis and a method involving dye binding. Methods of protein fractionation involving dye binding are satisfactory for routine use provided the limitations of these methods are recognized.
Determination of Cholesterol by Means of Phloroglucinol in Acid Solution
Authors: Sahagian Benjamin , Levine Victor E
Published: January 2020

Cholesterol is determined by taking advantage of the fact that the digitonin moiety of cholesteryl digitonide is a glycoside containing in its molecular structure one molecule of xylose and four molecules of galactose, and therefore reacts with a sugar reagent, such as phloroglucinol in acid solution, to form a stable color complex yielding quantitative results when measured spectrophotometrically. The method agrees well with results obtained by the Schoenheimer and Sperry (8) procedure.
Determination of Phenylalanine in Blood and Urine
Authors: Woolf L I , Goodwin B L
Published: January 2020

A modification is described of the method of LaDu and Michael for estimating the concentration of L-phenylalanine and L-tyrosine in the blood by oxidation with L-amino acid oxidase. The proteins of serum or plasma are removed in an ultra-filtration step that greatly reduces the nonspecific absorption, increasing the sensitivity and precision of the method. The ultrafiltrate is added to a composite reagent containing all other necessary components. The method can be applied to urine after removal of pigments with basic lead acetate.
Determination of Free and Total Indole-3-acetic Acid and of the Indole Index
Authors: Fischl J , Rabiah S
Published: January 2020

A new method is described for measurement of the urinary excretion of free and total indole-3-acetic acid and for obtaining the chromogenic value of the total indoles. The color reaction employed is Fischl's (1) tryptophan reaction. Hydrolysis and extractions were done by Weissbach's (2) procedure. The ratio of the various fractions is expressed by a new term: "indoles index" (I.I.). By the evaluation of the data obtained under various conditions, many abnormalities of tryptophan metabolism may be detected.
An Observation Concerning the Bratton-Marshall Diazo Reaction in Sulfonamide-free Urine
Authors: Annino Joseph S
Published: January 2020

The diazo reaction commonly used for the quantitative determination of sulfonamides is positive in urine which is free of sulfa drugs. The reacting substance apparently is present in all urine.
A Semimicro Modification of the Karr Urea Determination Method Using the Somogyi Serum Filtrate
Authors: Ryland Margaret E
Published: January 2020

A semimicro adaptation of the Karr method that uses a 1:21 Somogyi filtrate is described. The method compares favorably with the Karr method and the Van Slyke and Cullen aeration method.
Optimum Clinical Application of Serum Protein Electrophoresis
Authors: Dirstine P H , MacCallum D B , Anson J H , Mohammed Anis
Published: January 2020

The clinical employment of serum protein electrophoresis on microporous cellulose actate support medium is described. The high precision, the freedom from error in routine use, and the speed and economy of the procedure recommend it as a replacement for the routine "salting-out" A/G ratio in most laboratories and as a five-fraction separation procedure which is a great improvement over paper electrophoresis and much easier than gel methods. Normal values, precision data, and information on time requirements are given, as are examples of potential value of the obtained information in acute conditions and in routine physical examinations.
Chemical Assay of Diethylstilbestrol
Authors: Dryer R L
Published: January 2020

A method for the chemical determination of diethylstilbestrol has been described which is useful for the assay of this drug and for its determination in tissue extracts. The procedure has been validated for the range of 0.005-0.125 mg., in which Beer's law is obeyed. A limited number of substances has been examined for possible interference, all of which gave negative results. Fats or lipoids do not prevent the formation of a colored complex, but the turbidity due to their presence interferes with exact color measurements.
Cholesterol in Serum and Lipoprotein Fractions
Authors: Anderson Joseph T , Keys Ancel
Published: January 2020

1. Methods are described for the separation, by paper electrophoresis and by cold ethanol, of α- and β-lipoproteins in 0.1 ml. of serum, with subsequent analysis of cholesterol in the separated portions.

2. It is shown that both methods of separation yield separated fractions containing substantially the same amounts of cholesterol.

3. Detailed data are given on the errors of measurement for total cholesterol and for cholesterol in the separated lipoprotein fractions.

4. Studies are reported on the stability of cholesterol in stored serum and on paper electrophoresis strips. It is shown that simple drying on filter paper causes no change in cholesterol content and yields a product that is stable for many weeks at ordinary room temperature.

5. The sources of variability in human serum cholesterol values are examined and it is shown that spontaneous intraindividual variability is a much greater source of error than the errors of measurement with these methods.
Absorption and Excretion of 17, 21-Dihydroxy-20-Ketosteroids in Dogs
Authors: Silber Robert H , Morgan Evan R
Published: January 2020

The plasma concentrations of free 17,21-dihydroxy-20-ketosteroids and urinary excretion of both free and glucuronide forms have been determined after oral, intramuscular, and intravenous administration of cortisone, hydrocortisone, their δ1 forms, and 9α-fluorohydrocortisone to dogs.

Excretion of the glucuronide forms of those steroids with a double bond at the 1-2 position or with a fluorine at position 9 was depressed, and the plasma half-life of each of these steroids was longer than that of the parent compound.
Serum Iron Determination
Authors: Kingsley George R , Getchell Gloria
Published: January 2020

1. A sensitive, reproducible method for serum iron determination has been developed employing extraction of serum acid hydrolysate with isoamyl alcohol and development of a highly colored ferrous complex of 4,7-diphenyl-1, 1O-phenanthroline for quantitative photometric measurement of iron.

2. The method gives good recoveries and also good agreement with the dry-ashing procedure.

3. A normal range of 120-200 µg./100 ml. (average 160) for the female and 125-238 µg./100 ml. (average 182) for the male for serum iron was obtained by the method.
Simplified Rapid Technic for the Extraction and Determination of Serum Cholesterol without Saponification
Authors: Carr Julius J , Drekter I J
Published: January 2020

An accurate yet simple procedure for the determination of total cholesterol, based upon the application of a Liebermann-Burchard color reaction directly in the solvent employed for extraction of cholesterol from serum, has been described. Extraction of cholesterol and removal of protein are accomplished by means of acetic acid and acetic anhydride. Serum water is removed by the acid-catalyzed hydrolysis of acetic anhydride. The Liebermann-Burchard color is then developed with a stable, modified reagent consisting of equal volumes of H2SO4 and acetic acid.

Excellent agreement with the technic of Schoenheimer and Sperry is obtained. Equal intensities of color are produced by equivalent concentrations of free and esterified cholesterol. Preliminary saponification of cholesterol esters is therefore not required. Color development may proceed in ordinary room lighting without loss of accuracy.
Plasma Tributyrinase in the Neonatal Period
Authors: Friedman Max M , Shriro Robert L
Published: January 2020

A method is described for the microestimation of tributyrinase activity in plasma that requires only 0.1 ml. of sample. This is an electrometric procedure adapted from a titrimetric method.

A comparison curve is established which relates titration units to electrometric units.

Data are presented for the plasma tributyrinase levels in the first 6 days of neonatal period. No significant daily variations could be detected.
Nitrofurantoin Estimation in Urine with the Aid of Chromatography
Authors: Bender Raymond C , Nohle Esther G , Paul Mary F
Published: January 2020

A method for the determination of Furadantin in urine has been described. Furadantin is separated from interfering urinary pigments by a chromatographic adsorption technic. Furadantin concentration may then be determined spectrophotometrically from the absorbance (375 mµ) of the eluate, or the eluate may be further treated to form the phenylhydrazone of nitrofuraldehyde from Furadantin and the determination carried out colorimetrically.
Determination of Serum Urate by Direct Acid Fe3+ Reduction or by Absorbance Change (at 293 nm) on Oxidation of Urate with Alkaline Ferricyanide
Authors: Morin Leo G
Published: January 2020

An acid ferric reduction procedure is described for determining serum urate with 2,4,6-tripyridyl-s-triazine at 593 nm, whereby each mole of urate reduces 4 moles of ferric ion. The procedure requires no deproteinization and as little as 20 µl of serum is needed. It gives results that are linearly related to concentration to about 30 mg/dl, and it is precise (CV, 2.6%), accurate, and sensitive (a = 538). An ultraviolet spectrophotometric procedure is also described, in which urate is determined from the difference in absorbance at 293 nm with and without alkaline ferricyanide oxidation of urate. This procedure also is linear to at least 15 mg/dl, precise (CV, 1.2%), and accurate. Results by both procedures agree and correlate well with a reference uricase method. More than 99% of urate added to serum can be accounted for analytically.
Design and Operation of a Signal Comparator to Increase Efficiency of Continuous-Flow Analyzers
Authors: Neeley W E , Wardlaw S , Swinnen M E T
Published: January 2020

Design features and operation of a signal comparator are described. The efficiency of continuous-flow analyzers is improved by allowing the bubbled stream to remain intact as it passes through the colorimeter flow cell. The signal comparator eliminates the bubble artifact from the photodetector signal while allowing the signal produced from the fluid segment to remain intact. The instrument is reliable, easy to use, and does not require any adjustments by a technician.
Rocket Immunoselection for Detection of Heavy-Chain Diseases
Authors: Gale D S J , Versey J M B , Hobbs John R
Published: January 2020

A method is described that allows heavy-chain disease proteins to be simply detected. The sample is electrophoresed in an agarose plate containing kappa and lambda antisera in the lower section, and the relevant heavy-chain antisera in the upper section. Light chains and immunoglobulins containing light chains are precipitated in the lower region. Free "heavy chains" migrate into the upper region, where they are precipitated as a separate rocket. The method is quick, sensitive, and requires little antiserum.
New Evidence for a Binding Principle Specific for Folates as a Normal Constituent of Human Serum
Authors: Zettner Alfred , Duly Peggy E
Published: January 2020

The binding of folate by human serum was investigated by incubating serum with [3H]pteroylglutamic acid followed by charcoal separation of free and bound fractions. Sera from all of 99 normal volunteers and 9 16 patients exhibited some degree of folate binding, ranging from less than 0.1 to greater than 8 ng/ml. This binding phenomenon was found, by competitive inhibition, to be specific for folate derivatives when we used pooled serum as well as 10 individual sera representative of the entire range of folate binding as encountered in the total of 1015 sera. Studies of the association and dissociation reactions of folate and serum indicated that the binding reaction is of the reversible type. Hence, a mass-action equilibrium must also exist in vivo between bound and free folate fractions. The binding principle appears to be protein in nature. The implications of the interference of this binder in competitive binding assays of serum folates are discussed.
Comparison of Electroimmunodiffusion and Radial Immunodiffusion for Measurement of IgG in the Laboratory Diagnosis of Multiple Sclerosis
Authors: Perry J Joseph , Bray Patrick F , Hackett Theodore N
Published: January 2020

The detection of a supranormal quantity of immunoglobulin G (IgG) in cerebrospinal fluid is valuable in diagnosis of multiple sclerosis. In a previously published study of over 300 patients, including 46 patients with a clinical diagnosis of multiple sclerosis, 74% of the patients were found to have an abnormally high IgG value, expressed as a ratio of IgG/albumin, by the reliable method of electroimmunodiffusion. In the present study the recently introduced method of radial immunodiffusion was compared with established electroimmunodiffusion technique in divided samples of cerebrospinal fluid from 49 patients with a wide range of IgG/albumin values. The correlation of the results obtained by these two methods was very good (r = 0.945), but the variance with radial immunodiffusion (±20%) is greater than with electroimmunodiffusion (±15%). Two samples that exhibited increased values by the electroimmunodiffusion method were normal with the other technique. We conclude that electroimmunodiffusion remains a slightly more accurate and sensitive technique, although radial immunodiffusion is simpler and requires less technician time.
Simplified Colorimetry of α-Amino Nitrogen in Plasma, Serum, or Urine
Authors: Lorentz Klaus , Flatter Barbara
Published: January 2020

We describe a simple procedure for estimating amino acids, based on the formation of charge-transfer complexes with p-benzoquinone. The reaction is insensitive to ammonia, urea, purines, creatinine, and other nitrogenous compounds present in serum or urine, except amines, peptides, and proteins. The reagent is cheap, stable, and does not require prior treatment of urine before determination. Specifity, precision, and normal values of this method are reported and compared with those obtained by a colorimetric ninhydrin technique.
Simultaneous Determination of Copper and Iron in a Single Aliquot of Serum
Authors: Yee Hugh Y , Goodwin Jesse F
Published: January 2020

Copper and iron may be sequentially measured in a single aliquot of a protein-free filtrate by use of bis (1 -piperidylthiocarbonyl) disulfide and disodium 3-(2-pyridyl)-5,6-bis(4-phenylsulfonic acid)-1,2,4-triazine (also known as ferrozine). Recovery studies showed excellent results for both metals in various concentrations. Copper interference has been obviated by use of thiourea in mercaptoacetic acid. Simultaneous equations are not needed in calculating results and high-reading blanks are eliminated. Comparative results are given with methods in which each metal was measured singly.
Determination of Sulfonylureas and Metabolites by Pyrolysis Gas Chromatography
Authors: Aggarwal Vijay , Sunshine Irving
Published: January 2020

We describe a simple, rapid method for determination of sulfonylureas that is not susceptible to significant interference from metabolites. An acidified plasma is extracted with toluene, followed by a back extraction from the toluene to methanolic trimethylanilinium hydroxide. The resulting compounds are measured by gas chromatography.
Identification of Free and Conjugated Metabolites of Methaqualone by Gas Chromatography—Mass Spectrometry
Authors: Bonnichsen R , Mårde V , Ryhage R
Published: January 2020

Gas chromatography—mass spectrometry was used to identify and measure methaqualone metabolites. All samples were silylated before analysis. Free and conjugated metabolites of methaqualone in urine, liver, and blood were studied in three suicide cases. Both free and conjugated metabolites were found in blood and urine, only free metabolites in liver. The conjugated metabolites were hydrolyzed with hydrochloric acid. A comparison hydrolysis with β-glucuronidase showed that much of the sample was destroyed by hydrolysis with hydrochloric acid. Mass chromatography is presented as a computer-based gas chromatographic—mass spectrometric method.
Chromogenic-Substrate Method for Demonstrating Multiple Forms of Alpha-Amylase after Electrophoresis
Authors: Spiekerman A M , Perry P , Hightower N C , Hall F F
Published: January 2020

A chromogenic-substrate method is described for demonstrating multiple forms of alpha-amylase (isoamylases) after they have been electrophoretically separated in a continuous-buffer, slab-type, polyacrylamide-gel system. After electrophoresis, the various isoamylases are detected by layering the gel slabs onto thin-film plates of agar impregnated with Remazolbrilliant Blue starch. Isoamylases appear on the substrate plates as clear hydrolytic zones on a blue background of undigested substrate. After dehydration, the substrate plates can be stored indefinitely, and the polyacrylamide slabs are available for protein staining or elution of the isoamylase bands, if desired. This method has significant advantages: it is simple, substrate plates are easy to prepare, the plates can be permanently stored, optimum time required for isoamylase detection can be judged visually, and the method can be adapted for special two-dimensional electrophoretic studies.
Enzymatic Method for Determination of Inorganic Phosphate in Serum and Urine with a Centrifugal Analyzer
Authors: Pesce Michael A , Bodourian Selma H , Nicholson John F
Published: January 2020

We describe an enzymatic method for determining inorganic phosphate in serum and urine, with use of the "CentrifiChem." The sample is mixed with a combined enzyme—substrate system consisting of the enzymes phosphorylase a, phosphoglucomutase, and glucose-6-phosphate dehydrogenase, the coenzyme NADP, the substrate glycogen, and adenosine 5'-monophosphate as the activator for phosphorylase. The increase in absorbance at 340 nm as NADPH is formed is linearly proportional to the concentration of inorganic phosphate to 15 mg P/dl. This method circumvents deproteinization and requires only 10 µl of sample. Results obtained with the automated enzymatic method show good correlation with manual and automated molybdenum blue methods.
Single-Antibody Technique for Radioimmunoassay of Cortisol in Unextracted Serum or Plasma
Authors: Foster Lowell B , Dunn Ralph T
Published: January 2020

A radioimmunoassay procedure for cortisol is described that requires only 5 µl of serum or plasma. Native cortisol-binding proteins are denatured by heating 5 µl of sample in 0.2 ml of glutamate buffer in a boiling water bath for 15 min. After a 2-h incubation of heat-treated serum or plasma with [H3]cortisol and cortisol antibody, "free" and "bound" cortisol are separated by use of hemoglobin-coated charcoal. The method is easy and sensitive, and results compare favorably with those of a well-accepted acid-fluorescence method. In addition, we show that serum and heparinized plasma yield the same results by this method, and therefore either can be assayed by this procedure.
Plasma Cortisol Determination: Radioimmunoassay and Competitive Protein Binding Compared
Authors: Farmer Robert W , Pierce Charles E
Published: January 2020

A simple radioligand assay has been developed for measuring cortisol in plasma and urine. The antiserum was produced in rabbits by using cortisol-21-hemisuccinyl-bovine serum albumin as the antigen. The standard curve was linear from 0-1000 pg. A small aliquot of ethanol-precipitated plasma or urine is directly assayed. Interassay variability of 56 separate assays of a normal plasma pool during six months was: mean, 224 µg/liter; range, 210-238 µg/liter; CV, 3.2%. In assay of multiple samples obtained between 0800 and 1800 hours from normal young men, radioimmunoassay (RlA) gave consistently lower values than did competitive protein binding (CPB). The relationship, as calculated from results for 41 single samples, is expressed by the equation RIA = 0.713 CPB + 0.59, suggesting that the normal range for RIA should be 35-180 µg/liter rather than the 50-250 µg/liter usually cited. Although there is crossreactivity with 11-deoxycortisol, this assay is clearly superior to CPB: it is more specific, has a wider range (<8-400 µg/liter), and requires less technician time.
Preparation and Evaluation of a Water-Soluble Cholesterol Standard
Authors: Klein Bernard , Kleinman Norman B , Foreman James A
Published: January 2020

We synthesized some inorganic and organic salts of cholesteryl hemisuccinate. Aqueous solutions of the morpholine salt, at concentrations equivalent to 400 mg of cholesterol per deciliter, have been evaluated as aqueous cholesterol standards and compared to alcoholic cholesterol solutions in analyses for cholesterol in serum, as performed by two analytical reference procedures. No significant differences were found. The usefulness of solutions of this salt as additives for serum controls or recovery studies has been also demonstrated.