bluuebunny/crossref_metadata_2025 huggingface dataset:
CMS experiment: Physics overview
Authors: Alexakhin Vadim
Published: January 2020

An overview of physics results from the CMS experiment at the LHC is given. The present analysis is based on data obtained for colliding proton beams at the c.m. energies of

s

=
8

and 13 TeV over the period of LHC Run-1 and Run-2.

New unique data on interactions of Standard Model particles at record energies were obtained in the course of the first run of LHC operation. The Higgs boson was discovered, and investigation of its properties was initiated. Measurements were performed for Standard Model processes, including rare and previously unobserved ones. This permitted refining some parameters of the Standard Mode and setting limits on the parameters of some theoretical models beyond the Standard Model, for example, on the masses of new particles, on the fundamental energy scales, on the coupling constants, and on the cross sections for the production of new particles.
Overview of recent HERMES results
Authors: Marukyan Hrachya
Published: January 2020

The HERMES experiment has collected a wealth of data using the 27.6 GeV polarized HERA lepton beam and various polarized and unpolarized gaseous targets. This allows for a series of unique measurements of observables sensitive to the multidimensional (spin) structure of the nucleon, in particular semi-inclusive deep-inelastic scattering (SIDIS) measurements.

In this contribution, transverse single-spin asymmetry, longitudinal single- and double-spin asymmetries in SIDIS will be presented. The azimuthally uniform double-spin asymmetries using longitudinally polarized nucleons constrain the flavour dependence of the quark-spin contribution to the nucleon spin. For a first time, such asymmetries are explored differential in three dimensions in Bjorken-x and the in the hadron kinematics z and P

h± (which respectively represent the energy fraction and transverse momentum of the final-state hadron) simultaneously. This approach increases the quark-flavour sensitivity and allows to probe the transverse-momentum dependence of the helicity distribution. The measurement of hadron charge-difference asymmetries allows, under certain simplifying assumptions, the direct extraction of valence quark polarisations.

The azimuthal modulation of this double-spin as well as of the single-(beam)spin asymmetry probe novel quark-gluon-quark correlations through twist-3 distribution and fragmentation functions. Also here, asymmetries are explored in several dimensions. Furthermore, in case of the beam-spin asymmetry, results for electro-produced protons and antiprotons have become available. The beam-spin asymmetries for pions are compared to similar measurements for pions at CLAS and unidentified hadrons at COMPASS.
Effects of urbanization on food-energy-water systems in mega-urban regions: a case study of the Bohai MUR, China
Authors: Deng Caiyun , Wang Hongrui , Gong Shuxin , Zhang Jie , Yang Bo , Zhao Ziyang
Published: January 2020

The security of food-energy-water (FEW) systems is an issue of global concern, especially in mega-urban regions (MURs) with high-density populations, industries and carbon emissions. To better understand the hidden links between urbanization and FEW systems, the pressure on FEW systems was quantified in a typical rapidly urbanizing region—the Bohai MUR. The correlations between urbanization indicators and the pressure on FEW systems were analyzed and the mechanism of the impact of urbanization on FEW systems was further investigated. The results showed that approximately 23% of cropland was lost, 61% of which was lost via conversion to construction land and urban areas expanded by 132.2% in the Bohai MUR during 1980–2015. The pressure on FEW systems showed an upward trend, with the stress index of the pressure on FEW systems (FEW_SI) ranging from 80.49% to 134.82%. The dominant pressure consisting of that has converted from water system pressure to energy system pressure since 2004. The FEW_SI in the Bohai MUR was enhanced with cropland loss and increases in urbanization indicators. Additionally, land use, populations, incomes, policies and innovation are the main ways that urbanization affects FEW systems in MURs. This study enhances our understanding of the variation in pressure on FEW systems in MURs and the effects of urbanization on FEW systems, which will help stakeholders to enhance the resilience of FEW systems and promote sustainable regional development.
Contrasting contributions of flows on different time scales to tropical cyclone tracks over the South China Sea
Authors: Cao Xi , Wu Renguang , Bi Mingyu
Published: January 2020

This study investigates the relative contributions of components of flows on multiple time scales to westward and eastward-moving tropical cyclones (TCs) over the South China Sea (SCS) from a local and instantaneous perspective of TC position along the TC tracks during June to October from 1965 to 2015. The total steering flows obtained by vertical integration of winds from 850 to 300 hPa averaged along the entire TC tracks are separated into climatological mean flows, interannual, intraseasonal, and synoptic time scales. For westward-moving TCs, the zonal steering flows are contributed dominantly by climatological mean easterly, whereas the meridional steering flows are contributed dominantly by climatological mean and synoptic-scale southerly winds. In contrast, for eastward-moving TCs, the zonal steering flows are contributed equally by the intraseasonal and synoptic components, while the meridional steering flows are contributed dominantly by climatological mean southerly winds along with the secondary contribution of synoptic-scale southerly winds. This work provides a better understanding of relative contributions of different time scale components of steering flows to the TC motions over the SCS.
Utilizing smart-meter data to project impacts of urban warming on residential electricity use for vulnerable populations in Southern California
Authors: Chen Mo , Ban-Weiss George A , Sanders Kelly T
Published: January 2020

Extreme heat events are increasing in frequency and intensity, challenging electricity infrastructure due to growing cooling demand and posing public health risks to urbanites. In order to minimize risks from increasing extreme heat, it is critical to (a) project increases in electricity use with urban warming, and (b) identify neighborhoods that are most vulnerable due in part to a lack of air conditioning (AC) and inability to afford increased energy. Here, we utilize smart meter data from 180 476 households in Southern California to quantify increases in residential electricity use per degree warming for each census tract. We also compute AC penetration rates, finding that air conditioners are less prevalent in poorer census tracts. Utilizing climate change projections for end of century, we show that 55% and 30% of the census tracts identified as most vulnerable are expected to experience more than 16 and 32 extreme heat days per year, respectively.
Synthesis and luminescent properties of novel red-emitting Eu(III) complexes based on alanine aliphatic derivatives with different optical rotation
Authors: Zhang Xue , Xie Andy , Wu Yuewen , Gao Zihan , Xie Hongde
Published: January 2020

A series of novel luminescent amino acid-rare earth complexes (denoted as Eu(L/D-SA)3-Phen) have been successfully synthesized. Using stearoyl alanine (denoted as SA) with different optical rotations as the first ligand and 1,10-phenanthroline (Phen) as the second ligand, the products were prepared by solution chemical reaction. Fourier transform infrared spectrometer (FT-IR), nuclear magnetic resonance spectroscopy (1H NMR), x-ray diffraction (XRD), scanning electron microscope (SEM), ultraviolet and visible spectrum (UV) and photoluminescence spectroscopy were used to characterize the properties of Eu(L/D-SA)3-Phen. FT-IR, 1H NMR and XRD indicate that ligand SA and Phen were prepared and successfully combined with Eu3+ ions. SEM analysis shows relatively uniform morphological structure. Eu(L/D-SA)3-Phen exhibit a typical luminescence emission peak at 614 nm. In addition, the lifetimes of Eu(L/D-SA)3-Phen are in scale of millisecond. The relationship between fluorescence intensity of Eu(L/D-SA)3-Phen and the optical rotation of ligand SA has been studied and discussed. Based on the results, Eu(L/D-SA)3-Phen have excellent luminescent performance and possess potential application as luminescent materials.
Sensitivity of the Nipple-Areola Complex in Reduction Mammaplasty Following Periareolar Dermis Section
Authors: de Sá Jairo Zacchê , Braga Antônio Carlos Côrte Real , Barreto Rafael Henrique Coutinho , Ramos Anderson da Silva , de Oliveira Rodrigues Amanda Estelita , Santa-Cruz Fernando , Aguiar José Lamartine de Andrade
Published: January 2020

Background

Preservation of the periareolar dermis, after de-epithelization in reduction mammaplasty, may result in reduced nipple-areola complex (NAC) mobility. Consequently, distortion in shape and difficulty correcting the areola position can occur.

Objectives

The aim of this study was to evaluate NAC viability and sensitivity resulting from periareolar dermis section after de-epithelization in patients who underwent reduction mammaplasty surgery.

Methods

This study was a randomized, controlled double-blind clinical trial. A total of 41 patients (82 breasts) were randomly allocated into 2 groups and underwent reduction mammaplasty—involving the superior pedicle—with a final inverted T-shaped scar. A sectioning of the periareolar dermis was performed on the breasts in the experimental group. Semmes-Weinstein monofilaments were used to evaluate NAC sensitivity at the preoperative evaluation, and 3, 6, and 52 weeks after surgery.

Results

No cases of partial or total NAC necrosis were noted in either group. The comparison between the groups did not show significant differences regarding NAC sensitivity. However, a statistically significant difference was noted when sensitivity levels at the preoperative evaluation and 3 weeks after surgery were compared in the experimental group. A significant difference was noted when the scores of the sensitivity 3 weeks after surgery were compared between the control and the experiment groups. Nevertheless, after 1 year, no statistical differences were observed in the experimental group or between both groups.

Conclusions

The sectioning of the periareolar dermis does not affect the viability or the pressure sensitivity of the NAC.

Level of Evidence: 4
Addressing the heterogeneity in liver diseases using biological networks
Authors: Lam Simon , Doran Stephen , Yuksel Hatice Hilal , Altay Ozlem , Turkez Hasan , Nielsen Jens , Boren Jan , Uhlen Mathias , Mardinoglu Adil
Published: January 2020

The abnormalities in human metabolism have been implicated in the progression of several complex human diseases, including certain cancers. Hence, deciphering the underlying molecular mechanisms associated with metabolic reprogramming in a disease state can greatly assist in elucidating the disease aetiology. An invaluable tool for establishing connections between global metabolic reprogramming and disease development is the genome-scale metabolic model (GEM). Here, we review recent work on the reconstruction of cell/tissue-type and cancer-specific GEMs and their use in identifying metabolic changes occurring in response to liver disease development, stratification of the heterogeneous disease population and discovery of novel drug targets and biomarkers. We also discuss how GEMs can be integrated with other biological networks for generating more comprehensive cell/tissue models. In addition, we review the various biological network analyses that have been employed for the development of efficient treatment strategies. Finally, we present three case studies in which independent studies converged on conclusions underlying liver disease.
Empirical likelihood test for a large-dimensional mean vector
Authors: Cui Xia , Li Runze , Yang Guangren , Zhou Wang
Published: January 2020

This paper is concerned with empirical likelihood inference on the population mean when the dimension $p$ and the sample size $n$ satisfy $p/n\rightarrow c\in [1,\infty)$. As shown in Tsao (2004), the empirical likelihood method fails with high probability when $p/n>1/2$ because the convex hull of the $n$ observations in $\mathbb{R}^p$ becomes too small to cover the true mean value. Moreover, when $p> n$, the sample covariance matrix becomes singular, and this results in the breakdown of the first sandwich approximation for the log empirical likelihood ratio. To deal with these two challenges, we propose a new strategy of adding two artificial data points to the observed data. We establish the asymptotic normality of the proposed empirical likelihood ratio test. The proposed test statistic does not involve the inverse of the sample covariance matrix. Furthermore, its form is explicit, so the test can easily be carried out with low computational cost. Our numerical comparison shows that the proposed test outperforms some existing tests for high-dimensional mean vectors in terms of power. We also illustrate the proposed procedure with an empirical analysis of stock data.
Reproducibility and Validity of Sodium Sulfate Fractionation of Proteins in Plasma and Knee Joint Fluid
Authors: Gaebler O H , Beher W T , Sigler J W , Galpin R R
Published: January 2020

Blood was drawn from 14 laboratory workers under conditions similar to those under which blood samples are taken from ambulatory clinic patients. The sera were analyzed for the various proteins by the method of Mine. Eighteen knee joint fluids were analyzed by the same method; and 8 fluids from one patient were also analyzed electrophoretically. Results for these 8 fluids, and for all of the sera, are presented in tabular form and discussed. A component moving faster than albumin was noted in all knee joint fluids. This could not be concentrated from a pooled lot from 4 patients by electrophoresis-convection, but disappeared instead.
Purification of Chromium (VI) for Use in the PBI Determination
Authors: Mason W Burkett , Coco Santo
Published: January 2020

Chromium (VI) which is essentially free of iodine can be prepared by converting CrO,3 to CrO2Cl2. The crude chromyl chloride can be used with concentrated sulfuric acid for wet combustion of serum in the PBI determination.
Recent Studies of Fat Digestion and Absorption
Authors: Reiser Raymond
Published: January 2020

A review of the mechanism of digestion and absorption of fat has been presented. A new working hypothesis is suggested, based on the uses of tracer techniques.
Iodine and Thiocyanogen Numbers of the Fatty Acids of Blood Plasma
Authors: Kibrick Andre C , Skupp S J
Published: January 2020

A method has been described for the determination of both iodine and thiocyanogen numbers of the fat isolated from human blood plasma by the Allen volumetric method. The values found in 13 normal individuals varied from 111 to 157 for iodine number and from 64 to 122 for thiocyanogen number. The differences between the two numbers varied between 9 and 78.
A Simple Microelectrophoretic Method Using Starch-Agar Gel
Authors: Hase Tatsuo
Published: January 2020

A simple microelectrophoretic method of protein analysis using the gel of starch agar mixture is described. The method is easily standardized and the results show consistency and reproducibility. Protein patterns obtained show higher resolution than those of paper or agar-gel electrophoresis and simulate that of starch-gel electrophoresis. Developed protein patterns are suitable to quantitative analysis by appropriate electrophotometric or ultraviolet-light scanning devices and can be preserved as permanent records.
A Study of the Starch-Iodine Complex: A Modified Colorimetric Micro Determination of Amylase in Biologic Fluids
Authors: Pimstone N R
Published: January 2020

The limitations, inaccuracies, and practical difficulties of saccharogenic methods are discussed. A modified colorimetric microdetermination of amylase is described in which the digestion of starch is measured by the decrease in the starch-iodine color. Experimental data show that there are two other serum factors that can also cause a fall-off in color: (1) an immediate 10-15% depression of color, probably due to serum proteins and countered by using serum in the control; (2) an acid-serum factor causing a progressive fall-off in color subsequent to the initial depression. Iodine prevents this, and must be added as soon as the acid has been added to stop the enzyme activity. Results of 189 consecutive assays of human sera are presented. Amylase activity of duodenal aspirate has been determined simultaneously by the method described and the Lagerlöf method. Results are compared. Changes in serum amylase and lipase levels in artificially produced pancreatitis in dogs are presented. Optimal conditions for amylase activity are reviewed, and in the light of these, different amyloclastic methods and their results compared. Achroic-point technics are briefly evaluated.
Analysis on Heat Coagulated Blood and Serum
Authors: Marymont Jesse H , London Morris
Published: January 2020

A direct ultraviolet absorption method that does not require uricase for the determination of serum urate is presented. Serum (0.3 ml.) is placed in the bottom of a 25 X 95-mm. shell vial and coagulated by immersion of the vial in boiling water for 2 min. The clot is overlaid with 3.0 ml. of water and the serum urate extracted for 60 min. at 37°. The absorbance of the extract is measured at 295 mµ, and the serum urate determined by comparison with the known absorption of pure urate at the same wavelength. The agreement between the direct ultraviolet method and a standard phosphotungstate reduction method is excellent in cases in which no medication is being administered. Some drugs absorb ultraviolet light, and in certain instances may be responsible for a discrepancy up to 1.5 mg./100 ml. between the two procedures. The method is extremely simple and requires no reagents.
A Turbulent Drier-Extractor and a Wide-Interface Extractor
Authors: Holmes Frederic E
Published: January 2020

A simpler modification of an original turbulent drier-extractor with provision for measuring moisture is presented, as well as methods for determination of lipids in serum and in urine in the wide-interface extractor, and a new use for the wide-interface extractor in washing extracts from the drier-extractor. The two extraction units described may also serve as a reference standard and may be preferred for routine lipid assays.
Clinical Studies on Glucose Metabolism via the Pentose Phosphate Pathway in Human Erythrocytes
Authors: Olmstead Edwin G , Lunseth John H
Published: January 2020

Glucose metabolism via the pintos phosphate pathway was studied by measuring accelerated O2 uptake of human erythrocytes in the presence of methylene blue. Erythrocyte 02 uptake was independent of age in 67 normal patients. Erythrocyte 02 uptake was increased in pernicious anemia in relapse and in 5 of 6 jaundiced patients but was normal in pernicious anemia in remission and in 20 cases of malignancies of various types. In the latter cases there was no correlation between erythrocyte 02 uptake and hemoglobin content or reticulocyte count.
Uses for a Holmium Oxide Filter in Spectrophotometry
Authors: MacDonald Roderick P
Published: January 2020

The use of a holmium oxide calibration filter is discussed for checking wavelength, trouble-shooting, and adjusting sensitivity of spectrophotometers. Correction tables may be prepared to permit setting the instrument to true wavelength. One spectrophotometer was found to have a wavelength error large enough to impair its usefulness in direct spectrophotometric methods.
Application and Modification of the Momose-Ohkura Fluorometric Determination of Blood Glucose
Authors: Bourne Bernadette B
Published: January 2020

Results of the fluorometric determination of normal and abnormal blood glucose by the method of Momose and Ohkura (2) are lower in many instances than those obtained by reduction methods. The sensitivity of the method was greatly increased by readings at an activation of 470 mµ, a previously unreported maximum for the reaction product, in 20% sulfuric acid. A modified method is presented which uses a 1:1000 dilution of 2 µl. of blood. Protein-free supernate equivalent to 0.5 µl. of blood is reacted. Final volume of fluorophore is 10 ml.
Evaluation of a Cholesterol "Kit"
Authors: Hald P M , Weinberg M S , Barnett R N , Lavietes P H , Seligson D
Published: January 2020

A rapid "kit" method (Chole-Tech) for cholesterol determination in serum was evaluated by comparison with the Abell method in one clinical laboratory and with the Bloor method in another. Discrepancies between individual results of these standard technics and the Chole-Tech method were so great and so random that the results cannot be considered comparable. The Chole-Tech method is too unreliable for clinical use. All laboratory kits should be critically appraised before use. Accuracy and specificity must not be sacrificed for convenience.
Photometric Determination of Urinary Proteins
Authors: Saifer Abraham , Gerstenfeld Shirley
Published: January 2020

Previous reports have dealt with application of a tryptophan method for determination of serum total (19) and gamma (20) globulins and CSF total globulins (21). The method has now been extended to the determination of urinary globulins.

Total urinary protein (including mucoprotein) was determined with the Lowry procedure after perchloric acid-acetone precipitation. Normal values on morning samples (32 subjects) are: T.P., 24.0 ± 19.6 mg./100 ml.; protein (albumin plus globulin), 6.9 ± 4.3 mg./100 ml.; mucoprotein, 17.1 ± 16.3; globulin, 4.4 ± 2.4, albumin, 2.5 ± 2.4; and A/G ratio, 0.58 ± .4 S.D. Preliminary data on patients with a variety of kidney ailments indicate that an increase in the urinary globulin fraction is a sensitive indicator of early renal damage.
Adaptation of the Berthelot Color Reaction for the Determination of Urea Nitrogen in Serum and Urine to an Ultramicro System
Authors: Mathies James C
Published: January 2020

Existing methods for the estimation of urea and ammonia nitrogen in biologic fluids by means of the Berthelot color reaction have been adapted to an ultramicro system for routine clinical analysis. The resulting procedure is convenient and accurate, and can be carried out using 5 µl. of sample or less.
Analyses on Heat-coagulated Blood and Serum
Authors: London Morris , Marymont Jesse H
Published: January 2020

A method is described that does not employ chemical precipitation for the quantitative separation of serum inorganic phosphate from the proteins present. The separation is accomplished by heat coagulation of serum and subsequent extraction of phosphate from the intact clot with dilute sulfuric acid. Serum (0.25 ml.) is placed at the bottom of a 25x95-mm. shell vial and coagulated in a boiling-water bath for 2 min. The resultant coagulum is firm, adherent to the container, and not easily disrupted; 6.0 ml. of O.3N H2SO4 is then added to cover the coagulum, and the phosphate extracted. The phosphate in the extract is determined by a phosphomolybdate reduction procedure.
A Microprocedure for the Determination of 4-Pyridoxic Acid in Urine
Authors: Woodring Muriel J , Fisher Dorothy H , Storvick Clara A
Published: January 2020

A microprocedure for the estimation of urinary 4-pyridoxic acid which is apparently specific, yet simple enough for routine clinical use, has been adapted from the Fujita et al. (16-17) and Reddy et al. (22) procedures. Average values for urinary 4-pyridoxic acid for 7 women ranged from 3.8 to 6.9 µM/24 hr. by this method. These values are compatible with average daily intakes of vitamin B6 and indicate that by this method interfering fluorescent substances have been removed by chromatography. Good agreement was obtained with replicate analyses.
Limitations in Clinical Use of a Screening Test for Protein
Authors: Watson Derek
Published: January 2020

Quantitative estimation of protein in cerebrospinal fluid, amniotic, and similar protein-poor body fluids by means of a widely used strip test is not reliable. For this purpose, the turbidity test of Meulemans (1960) appears satisfactory. The strip test is a convenient and reliable means of detecting protein (albumin-globulin mixtures) in the urine of pregnant women.
A Method For Quantitative Extraction of Urinary 5-Hydroxyindoleacetic Acid
Authors: Sochor Frances M
Published: January 2020

A method for the quantitative assay of urinary 5-hydroxyindoleacetic acid (5 HIAA) is presented. The limits of accuracy and precision obtained reflect good recovery and reproducibility. The relatively high recovery is largely due to maintaining a low distribution coefficient of 5-HIAA during purification of the aqueous extract with chloroform.
Solvent Coagulation of Serum Proteins
Authors: London Morris , Marymont Jesse H , Fuld Jeanne
Published: January 2020

The usefulness of 14 common organic solvents in lowering the temperature necessary for the heat coagulation of serum proteins is evaluated. Six of the compounds, when added to serum in final concentrations varying from 14.3 to 28.6% (v/v), result in the formation of a firm clot at 60°. Ethylene glycol monomethyl ether is effective at 50° at 22.8% (v/v). Lower concentrations are effective at higher temperatures. The boiling points of the six range from 65° (methanol) to 153° (N,N-dimethyl formamide).
An Electrophoretic Study of Serum Protein-bound Carbohydrate in Dysproteinemia
Authors: Evenson David J , McGuckin Warren F , McKenzie Bernard F , Hagedom Albert B
Published: January 2020

The glycoprotein hexose in the sera of patients having an electrophoretically homogeneous globulin fraction was studied by paper electrophoresis. The largest diagnostic category was multiple myeloma, but also included were cases of macroglobulinemia, primary systemic amyloidosis, lymphoma, collagen vascular disease, liver disease, and other conditions. The hexose contents of the pathologic globulin fractions were compared; only in the macroglobulins was this value of diagnostic significance, consistently averaging more than 3 times that in normal gamma globulin. In myeloma globulins there was a relationship between the hexose content and the electrophoretic mobility, with only an occasional value approaching the macroglobulin range in the faster electrophoretic mobilities.

It is shown that paper electrophoresis and the PAS staining technic, in conjunction with protein staining on a duplicate sample of serum, constitute a useful screening test for detection of increased concentration of macroglobulin in serum in a large percentage of cases of "hypergammaglobulinemia." Gel electrophoresis, immunologic typing, and ultracentrifugation studies then can be used for further elucidation of the type of abnormality present.
Protein Metabolism During Healing of Wounds
Authors: Williamson Martin B
Published: January 2020

The foregoing is illustrative of the available information on the alterations in the biochemical processes which occur during the healing of wounds. Many of the studies mentioned appear to make some aspects of the phenomena involved in the healing of wounds more understandable. Yet, these results are too isolated to form a clear and unified picture of the healing processes and the mechanisms which control them. It will be necessary to discover the mechanisms which bring about the changes in metabolism before a real understanding of the processes of wound healing can be obtained. Obviously, much more data are required before these mechanisms can become apparent.
Quantitative Electrophoresis of Serum Proteins on Paper
Authors: Wurm Moses , Epstein Frederick H
Published: January 2020

1. A procedure for paper electrophoresis has been described which gives highly reproducible protein patterns with good resolution and freedom from distortions.

2. Densitometry of protein bands on paper stained with bromphenol blue or Amidoschwarz 10B reveals that the logarithm of protein concentration is proportional to optical density and that Beer's law does not apply. Electrophoretic patterns of normal human serum evaluated in this manner give values in close agreement with those obtained by moving-boundary electrophoresis.

3. Confidence limits were determined for both methods.
Multiple Determinations with Moving-Boundary Electrophoresis
Authors: Oreskes Irwin , Corey Harold
Published: January 2020

A procedure has been described for the performance of multiple moving boundary electrophoresis experiments. By connecting two dual-analysis cells in series, 4 experiments at a time and 12 in a working day may be performed.
Sources of Error in Spectrophotometric Measurement of Aspartate Aminotransferase and Alanine Aminotransferase Activities in Serum
Authors: Rodgerson Denis O , Osberg Iris M
Published: January 2020

We examined the measurement of serum aspartate and alanine aminotransferase activities with a short-interval enzyme-activity analyzer. Double-beam spectrophotometry was used to elucidate the source of errors in such measurements. For both enzymes the principal error sources are: (a) the presence of endogenous substrate for lactate dehydrogenase, and (b) reaction of 2-oxoglutarate with serum glutamate dehydrogenase and ammonium ions added to the reaction mixture in admixture with the secondary enzymes of the coupled reactions. In the case of serum aspartate aminotransferase, a less important source of error is the reaction of serum alanine aminotransferase with endogenous substrate. Use of 2-oxoglutarate as a reaction initiator in conventional methods causes errors. Suitable blank reagent mixtures are described that permit accurate, rapid measurement of these activities by double-beam spectrophotometry in a short-interval enzyme-activity analyzer.
Effect of Energy-Rich Compounds on Release of Intracellular Enzymes from Human Leukocytes and Rat Lymphocytes
Authors: Wilkinson J Henry , Robinson Jean M
Published: January 2020

Experiments have been performed to determine some of the factors affecting the release of intracellular enzymes, in the hope of improving our understanding of the mechanisms whereby tissue enzymes reach the circulation in disease processes. The discharge of intracellular enzymes into the medium during prolonged incubation of human leukocytes and rat lymphocytes has been shown to be inversely related to their ATP contents. Incorporation of ATP into the medium has a marked protective effect against enzyme loss. Other high-energy phosphates, such as uridine triphosphate and phosphoenolpyruvate, which can readily be converted into ATP, also exert a protective effect, but creatine phosphate, which cannot be so converted owing to the low activity of creatine kinase in the cells, exhibits no such action. Glucose and certain intermediates of the glycolytic pathway also reduce the leakage of intracellular enzymes, an effect which parallels their concentrations in the media. ATP also protects rat lymphocytes against enzyme loss provoked by high potassium concentrations. It is suggested that the integrity of the cell membrane, as assessed by its ability to prevent the leakage of enzymes, depends on the energy content of the cell, a decrease of which may be a common factor in clinical situations associated with elevated enzyme activities in the serum.
Radioimmunoassay of Serum Triiodothyronine on Small, Reusable Sephadex Columns
Authors: Alexander Nicholas M , Jennings James F
Published: January 2020

We have developed a radioimmunoassay method for serum triiodothyronine on small (9 x 23 mm), reusable Sephadex G-25 columns. Recoveries of triiodothyronine added to sera are 97-105%, and the coefficients of variation for within-assay and between-assay determinations are 5.8 and 9.0% , respectively. Maximum sensitivity is in the hypothyroid range (0-100 ng of T3 per dl). Triiodothyronine concentrations (ng/dl) in human serum are (mean ± SD): euthyroid 96 ± 26, euthyroid females receiving oral contraceptives 132 ± 17, hypothyroid 24 ± 22, and hyperthyroid 263 ± 58. Mild hemolysis and lipemia do not interfere, but 10-20% artifactual elevation is found with icteric sera. Interference by thyroxine is negligible. An improved, reproducible carbodiimide coupling procedure for triiodothyronine—albumin (19:1) antigen is described. A parenthetic observation of potential importance is that immunized rabbits accumulate large concentrations (30 000-90 000 ng/dl) of serum bound triiodothyronine. Our procedure offers the advantages that, on a single column, triiodothyronine is quantitatively extracted from serum that is premixed with 125l-labeled triiodothyronine, serum proteins are removed, binding with antiserum is accomplished in 1 h, and the free and bound triiodothyronine are separated. The columns are regenerated for repetitive use by eluting residual iodothyronines with excess thyroxine-binding globulin (dilute plasma).
Warning Methods for Quality Control in Determinations of Serum Calcium
Authors: Hellbron D C , Eastman J W , Kelly D
Published: January 2020

We have examined quantitative warning methods based on the measurement of controls (reference samples) to signal day-to-day displacements in determinations of serum calcium. A warning procedure that uses the mean of two control values (Method 2) was compared to a procedure that tested the two control values individually (Method 1). A simulated baseline shift was used to approximate the mechanism of day-to-day displacement. The two methods compared were calibrated to signal a warning with equal frequency in the absence of shift; then the method that signaled with highest frequency under baseline shift was judged most effective. Some statistical models were evolved for the distribution of serum calcium control values. Theoretical comparisons based on these models showed Method 2 to be more effective on the average under a broad range of conditions. However, in an empirical comparison based on 253 pairs of control values, Methods 1 and 2 were about equally effective.
Thin-Layer Chromatographic Screening of Amino Acids in Plasma and Urine of Newborns
Authors: Century Bernard , Vorkink William P , Natelson Samuel
Published: January 2020

We describe a simple, rapid, and inexpensive unidimensional high-resolution thin-layer chromatographic procedure for screening for aminoacidopathies in newborns. Protein-free filtrates are prepared for ultrafiltration of as little as 10 µl of plasma. A rapid, inexpensive photographic method provides large, high-contrast pictures of the chromatograms for permanent records. A day’s samples can be completed in 3 h, including all phases of the procedure.
Factors Contributing to Intra-Individual Variation of Serum Constituents: 5. Short-Term Day-to-Day and Within-Hour Variation of Serum Constituents in Healthy Subjects
Authors: Winkel Per , Statland Bernard E , Bokelund Henning
Published: January 2020

We evaluated the variations in some serum constituents in a group of healthy young men for two selected time intervals: short-term day-to-day changes and within-hour changes. In the first case, we used a two-way ANOVA model to compute the main-day effect and the subject-day interaction terms, which were combined to yield the total day-to-day variation. A main-day effect was seen to be statistically significant only for acid phosphatase, while all of the 18 serum constituents except for sodium, calcium, and albumin demonstrated a statistically significant subject-day interaction. For the within-hour biologic variation, a three-way ANOVA model was used to analyze results of duplicate serum samples drawn at 1100 h and 1130 h on two different days. Although a significant main effect of hour was found only for total lipids and alkaline phosphatase, pooling the main effect of hour, subject-hour interaction, and subject-day-hour interaction terms resulted in a chemically significant variation for potassium, total protein, albumin, iron, total lipids, cholesterol, and bilirubin. The relationship of these biological fluctuations is compared to the expected analytical variation in all cases.
Effects of Intra-and Interindividual Variation on the Appropriate Use of Normal Ranges
Authors: Harris Eugene K
Published: January 2020

Normal ranges based on the distribution of single samples from a large number of individuals reflect both intra- and interindividual variation. If the average ratio of these two sources of variation is small, then, assuming gaussian distributions, the conventional normal range will usually include a larger than expected proportion of an individual's distribution of values. When the average ratio exceeds 1.4, the normal range will include a proportion either larger or smaller than expected, depending on whether the individual's variability is less than or greater than average intra-individual variation. Investigation of multivariate normal regions in certain cases where calculations are feasible produced similar results. With these numerical guidelines, data from recent blood-chemistry studies indicate that conventional normal ranges are likely to be less sensitive than desired to significant changes in an individual's biochemical state. This analysis supports the continued development and use of cumulative (in time) systems for reporting laboratory test results for individuals.
Studies on the Use of XAD-2 Resin for Detection of Abused Drugs in Urine
Authors: Kullberg M Peter , Gorodetzky Charles W
Published: January 2020

We describe a procedure for extracting weakly acidic, neutral, and basic drugs from urine by using a column of XAD-2 resin. Adsorption of drugs from 20 ml of urine buffered at pH 8.5 ± 0.5 at a controlled flow rate of 2.5 ml/min was greater than 89% for all drugs tested except aspirin. On eluting the drugs tested with acetone and methanol/chloroform, recoveries ranged from 75 to 93%. Overall recoveries of drugs from urine to a thin-layer chromatography plate were between 63 and 78%. The concentration of morphine added to normal urine that can be detected 99% of the time (95% confidence limits) by this method was 80 (65-100) µg/liter. We evaluated three methods for recovering morphine from morphine glucuronide added to urine, by using appropriate modifications of the XAD-2 resin extraction method. Hydrolysis of urine, hydrolysis of urine extracts adsorbed on XAD-2 resin, and hydrolysis of urine extracts from the XAD-2 resin followed by a solvent extraction gave 75%, 40%, and 10% recoveries of morphine, respectively.
Concentration of Glutethimide and Associated Compounds in Human Serum and Cerebrospinal Fluid After Drug Overdose
Authors: Gold Martin , Tassoni Ernest , Etzl Michael , Mathew George
Published: January 2020

Serum and cerebrospinal fluid of patients in coma owing to glutethimide overdose was assayed for glutethimide and associated compounds. The sample was extracted with chloroform and the extract assayed by gas-liquid chromatography on a column of "3% OV-17." Up to six constituents were found in serum in addition to glutethimide, only three of which were ever present in substantial quantity. The peaks seen on gas chromatography were numbered in order of elution. Glutethimide was peak No. 2. Peak No. 1 usually reached a maximum serum concentration in 10 or less hours, as did peak No. 4. Peak No. 3 reached a maximal serum concentration in 10 h or sooner also, but at 20 h the amount had changed little in most patients. Ambre and Fischer [Res. Commun. Pathol. Pharmacol. 4, 307 (1972)] speculate that peak No. 3 plays an important role in maintaining coma. Neither the pattern of change nor the relative concentrations in serum or cerebrospinal fluid on waking support their hypothesis.
Single-pH Extraction Procedure for Detecting Drugs of Abuse
Authors: Stoner Ramon E , Parker Connie
Published: January 2020

A method is presented for determining certain drugs of abuse in a single extract of urine. The urine sample is adjusted to pH 6.0 with a buffer containing bromcresol purple. Basic drugs, such as amphetamines and narcotics, form an organic salt with the ionized bromcresol purple, which is extractable with a mixture of chloroform and 2-propanol (3:1 by volume). At pH 6.0, weak acids such as barbiturates and neutral drugs such as glutethimide are also soluble in this solvent. Consequently, the major classes of drugs are extracted simultaneously. The extract is then concentrated and the individual drugs are determined by thin-layer chromatography in a solvent that will separate bromcresol purple from the drugs. Additional Keyphrases: drug screening #{ 149} toxicology #{ 149} thin-layer chromatography #{ 149} screening procedure Clinical Laboratory Service, West Side VA Hosp., 820 S. Damen Ave., Chicago, Ill. 60612.
Technology of Manually Operated Sampler Pipets
Authors: Wenk Robert E , Lustgarten Jack A
Published: January 2020

We have evaluated the performance of manually operated sampler pipets. Twenty-four instruments of various construction, manufacture, and delivery volume were evaluated. Pipet-delivered water and serum were repeatedly weighed under controlled environmental conditions, and precision and accuracy assessed. The pipets often failed to meet the manufacturer's stated tolerance limits. Consumers should calibrate these instruments in their own laboratories. Some of the manufacturer's recommendations for optimal performance are challenged. The manual samplers can substitute for oral pipets and permit safe, inexpensive, simple, and rapid transfer of liquids, if the user recognizes their operational characteristics and limitations in accuracy and precision.
Automated Measurement of Protease-Inhibitor Capacity of Serum, by Use of Chymotrypsin and Casein
Authors: Wenger Julius , Sundy Marian
Published: January 2020

Serum protease inhibitor activity was assessed from the ability of the serum to inhibit casein hydrolysis by α-chymotrypsin (EC 3.4.4.5). Unmodified AutoAnalyzer equipment was used in conjunction with a fluorimetric method for dialyzable tyrosyl peptides. Serum, diluted with tris(hydroxymethyl) aminomethane buffer, was added to a chymotrypsin solution to inhibit its activity. For 72 sera, the automated method was compared with a manual determination of trypsin inhibitor capacity. Results by the two methods correlate well, supporting previous evidence that trypsin and chymotrypsin-inhibitor capacities of serum are related. The present automated method has several advantages that make it useful for clinical studies.
Micromethod for Determining Total Iron-Binding Capacity by Flameless Atomic Absorption Spectrophotometry
Authors: Yeh Yu-Yan , Zee Paulus
Published: January 2020

Because of the large quantities of venous blood required, assays of total iron-binding capacity (TIBC) and serum iron are often omitted in diagnostic tests involving small children. As an alternative to the conventional method of assessing TIBC, we developed a micromethod based on flameless atomic absorption spectrophotometry (flameless AAS). Additionally, the standard microprocedure for determining serum iron was modified so that iron concentration could be estimated from the same iron standards used to calculate TIBC. With these procedures, only 20 µl of serum is required to prepare protein-free supernate for measurement of TIBC or serum iron with an atomic absorption spectrophotometer equipped with a graphite furnace and a recorder. The resulting TIBC, serum iron, and computed transferrin saturation values compared well with those obtained by conventional flame atomic absorption spectrophotometry. The correlation was statistically significant at the 99% confidence level. These flameless AAS micromethods provide an accurate and sensitive means of determining both TIBC and serum iron in a total of 40 µl of serum, a quantity easily collected from a fingertip puncture, and hence are appropriate for routine laboratory work in pediatric clinics and for large-scale nutrition surveys.
Evaluation of 1,10-Phenanthroline as a Reagent for Sialic Acid Determinations
Authors: Snyder S L , Mathewson N S , Sobocinski P Z
Published: January 2020

Use of o-phenanthroline as a reagent for determination of sialic acids was proposed by a previous investigator. This method was based on an increase in absorbance at 307 nm that occurred when solutions of o-phenanthroline and various sialic acids were mixed. It was postulated that the increased absorbance was a result of formation of specific complexes. Using N-acetylneuraminic acid, we found no evidence for complex formation. Our results indicate that the observations of the previous investigator resulted from shifts in the pH of the medium rather than from formation of specific complexes. Therefore o-phenanthroline is not a specific reagent for sialic acids and its use is not recommended.
Shortened Radioimmunoassay for Human Growth Hormone
Authors: Twomey S L , Beattie J M , Wu G T
Published: January 2020

We report a radioimmunoassay procedure for human growth hormone in serum, in which the assay mixture is incubated at 37 °C for a total of 5 h rather than at 4 °C for 48 h. There was no significant difference in results by the two methods, according to the Sign Test and the signed-rank statistical test of Wilcoxin. A comparison of results at the two temperatures demonstrated a Spearmann coefficient of rank correlation value of 0.94. With this facilitation, a laboratory can provide results on the same day that the sample arrives.
Urine Microscopy, an III-Defined Method, Examined by a Multifactorial Technique
Authors: Winkel P , Statland B E , Jørgensen K
Published: January 2020

The precision of routine urine microscopy for counting erythrocytes and leukocytes was evaluated by using a statistical research-planning technique, factorial experimental design. We examined the relative contribution of the technician preparing the urine specimen, the technician reading the urine slide, the time elapsed since receipt of the urine specimen, and the effect of the microscope used. Results obtained by various technicians differed significantly, because of variation in preparation techniques. This study demonstrates that the routine examination of urine for cellular components may be more imprecise than generally believed, and that the technique should be better defined. It is emphasized that the technique of factorial experiments can be used as an important tool for the design of a rational quality-control program.
Quantitative Analysis of Morphine in Urine by Gas Chromatography-Chemical Ionization-Mass Spectrometry, with [N-C2H3]Morphine as an Internal Standard
Authors: Clarke Pauline A , Foltz Rodger L
Published: January 2020

A highly sensitive and specific method is described for quantitative determination of morphine in urine. Used in the method is a gas chromatograph and a computerized, quadrupole mass spectrometer operated under chemical ionization conditions. Morphine concentrations as low as 5 ng/ml can be measured by selected ion monitoring, with N-trideuteromethyl morphine as the internal standard. The sensitivity and specificity of the method is illustrated by the detection and quantitation of morphine in urine after ingestion of cough medicine containing codeine.
Enzymatic Determination of Total Serum Cholesterol
Authors: Allain Charles C , Poon Lucy S , Chan Cicely S G , Richmond W , Fu Paul C
Published: January 2020

An enzymatic method is described for determination of total serum cholesterol by use of a single aqueous reagent. The method requires no prior treatment of sample and the calibration curve is linear to 600 mg/dl. Cholesterol esters are hydrolyzed to free cholesterol by cholesterol ester hydrolase (EC 3.1.1.13). The free cholesterol produced is oxidized by cholesterol oxidase to cholest-4-en-3-one with the simultaneous production of hydrogen peroxide, which oxidatively couples with 4-aminoantipyrine and phenol in the presence of peroxidase to yield a chromogen with maximum absorption at 500 nm. The method is reproducible, and the results correlate well with those obtained by automated Liebermann—Burchard procedures (AA-2 and SMA 12/60) and the method of Abell et al. The present method affords better specificity than those previously reported and has excellent precision.