bluuebunny/crossref_metadata_2025 huggingface dataset:
Equilibrium Shifts and Shocks in Dynamic Systems
Authors: Stanick N A , Kraynyukov N I
Published: January 2020

The article discusses a dynamic macroeconomic model used by monetary authorities to make decisions on the monetary policy, customizable using satellite models. Since this model is calibrated, it is necessary to evaluate the sensitivity of the model parameters. The parameters are estimated using the models of the transmission mechanism of monetary policy. Models are considered near the stationary hypersurface Ω. The Lyapunov function with the constraints obtained from satellite models was used to assess the sensitivity of the parameters of the dynamic macroeconomic model. The magnitude of innovative shocks determines the transition between stationary hypersurfaces of a dynamic system and structural changes in a dynamic model.
Simulation of vehicle collisions at an unregulated intersection based on the Monte Carlo method
Authors: Varnavsky A N , Rogulina A V
Published: January 2020

Currently advanced driver-assistance systems develop actively, which allow to signal to the driver about danger of collision of vehicles, necessary braking or changes of motion parameters of the car to prevent dangerous situations and accidents. The effectiveness of advanced driver-assistance systems from the parameters of their work. Therefore, the actual task is to set the optimal parameters of advanced driver-assistance systems. The values of such parameters in general can be both statistical and independent of the current road situation, and dynamic and depend on the current road situation. This problem cannot be solved without modeling dangerous situations, creating models of motion and collision risks, the results of which can be given recommendations for setting the parameters of the advanced driver-assistance systems. The aim of the work is statistical modeling collision vehicles on the unregulated crossroads and the evaluation dependency of probability collision from the parameters of the road situation. An analytical modeling of the movement of vehicles at the crossroads was used and a mathematical model of their collisions was built. With the help of statistical modeling a probability of their collision with different parameters road situation was rated. Received result can be used to configuration parameters management vehicle advanced driver-assistance systems, including dynamic.
Simulation of data distribution between server stations using fuzzy technologies
Authors: Vikulov E O , Denisov O V , Meshcheryakov V A , Denisova L A
Published: January 2020

This article is about development and modeling of data distribution system through the server stations. An algorithm for selecting a server for downloading data based on fuzzy logic is proposed. A simulation model of a server complex created by MATLAB / Simulink / SimEvents software is presented. This model allows us to study the server complex as a system with discrete states based on the theory of queuing systems. Numerical experiments on the distribution of data among servers using different algorithms for selecting a server for user loading data were carried out. The advantage of the proposed approach to server selection based on fuzzy inference is shown. This advantage is expressed in reducing the length of queues in the system and increasing the number of serviced requests for data processing by servers.
Effect of neodymium doping on microwave absorption property of barium hexaferrite in X-band
Authors: Goel Shivanshu , Garg Avesh , Gupta Raju Kumar , Dubey Ashish , Prasad N Eswara , Tyagi Sachin
Published: January 2020

M-type barium hexaferrite (BaFe12O19) particles are synthesized by using sol-gel auto-combustion reaction for microwave absorption study in X-band. Three different materials namely BaNd0.02Fe11.98O19 (Nd2), BaNd0.04Fe11.96O19 (Nd4) and BaNd0.06Fe11.94O19 (Nd6) have been developed by varying doping of neodymium in barium hexaferrite. The synthesis of particles has been confirmed using SEM micrographs and XRD diffraction pattern. The hysteresis study is carried out for saturation magnetization using vibrating sample magnetometer (VSM). As the doping concentration of neodymium increases, the saturation magnetization of the material is decreased from 47.272 emu g−1 to 16.479 emu g−1. The vector network analyzer (VNA) is used for complex permittivity and complex permeability measurements of the developed materials. Nd4 material shows highest values of permittivity and permeability losses among other developed materials. From the complex permittivity and complex permeability, the reflection loss results of the developed materials have been calculated. The maximum reflection loss of −33.17 dB was obtained for 2.2 mm pallet of BaNd0.04Fe11.96 and −10 dB bandwidth reaches 2.94 GHz.
Mangrove bark tannins as a Zn–P coating sealant for mild steel corrosion protection in 3.5% NaCl solution
Authors: Zainol Abidin Shahadad , Hussin M Hazwan
Published: January 2020

In this work, mangrove bark tannins have been studied as a sealant after Zn–P of mild steel. The efficiency of the sealant against the corrosion was tested by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarisation (PD) in 3.5% NaCl solution. The increased in the concentration of the tannin as a sealant increases the inhibition efficiency up to optimum concentration of 4 g l−1. The inhibition efficiencies of tannin methanol extract (TME) and 70% tannin acetone extract (TAE) were 83.52% and 71.12% respectively. The results obtained from EIS and PD were in a good agreement and complementary to each other. The double layer constant phase element capacitance (CPEdl) decrease indicated that a film form on the surface of the mild steel that retard the corrosion activities. Further, the pore modifications and elemental compositions were analyzed by scanning electron microscope (SEM) and energy dispersive x-ray (EDX).
First-principles study of the surface structure and stability of BC5
Authors: Li Cheng , Deng Kai , Li Jinxia , Sun Chunyan , Ma Pan , Chen Yanyan , Shi Xue-Rong
Published: January 2020

BC5 with both superhard and superconducting properties is expected to have important applications in many fields. In this work, the low-index surface structures and properties of BC5 have been identified by first-principles calculations. The surface stability decreased in the order of (011) > (010) > (101) > (100) > (110) > (111) > (001). The (011), (101), and (110) surfaces exhibit the strongest surface relaxation, followed by (111), and the (001) surface is the least. A DFT (density functional theory)-based Wulff construction of the equilibrium shape of BC5 shows that the surface with the largest exposure area is (011), followed by the (101) and (001) surfaces. Electronic analyses show that Pmma phase BC5 and all considered low-index surfaces exhibit metallic character where the surfaces are even stronger. Larger charge redistribution in the low-index surfaces is found compared with the bulk case.
Electrical properties and alkali-pathways simulation of new mixed conductor Na4Li0.62Co5.67Al0.71(AsO4)6
Authors: Marzouki Riadh
Published: January 2020

Polycrystalline sodium lithium-cobalt-aluminum arsenate, Na4Li0.62Co5.67Al0.71(AsO4)6, was synthesized by solid state reaction route and characterized by infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The title material is a member of β-Xenophyllite family which show 3D anionic framework with interconnecting tunnels where alkali-ion are located. Dense ceramic with relative density of 97% is obtained after planetary grinding of the synthesized powder followed by optimal sintering at 1113 K. The effect of grinding on microstructure of sample is controlled by Scanning Electron Microscope (SEM). The electrical study using impedance spectroscopy, in the 443–773 K temperature interval, show interesting electrical performance of the dense ceramic: σ
433K = 1.41 10–5 Scm−1 and the activation energy Ea = 0.449 eV. The alkali migration pathways in the anionic framework were simulated using Bond Valence Site Energy (BVSE) model to correlate structure with electrical properties of the studied material. The calculation results were compared to other β-Xenophyllite materials.
Increasing the silicon solar cell efficiency with transition metal oxide nano-thin films as anti-reflection coatings
Authors: Sagar Raghavendra , Rao Asha
Published: January 2020

Herein, we report the study on RF-sputtered transition metal oxide thin films of Zinc oxide, Magnesium oxide, and Aluminum oxide as an antireflection coating on silicon-based solar cells and their influence on energy conversion. The transmission spectrum of all sputtered metal oxides was studied using a UV-visible spectrophotometer. The phase formation and microstructure analysis of these sputtered oxides were studied using glass for the destructive test along with the device. The x-ray diffraction and cross-section scanning electron microscopy of sputtered glass confirmed a single-phase structure along with nearly equal desired deposition thickness. The thicknesses of sputtered films were estimated using variable angle ellipsometry and the same was confirmed from cross-section scanning electron micrograph. The chemical composition and oxidation state of thin films deposited on glass were established from x-ray photoemission spectroscopy. The ability of a fabricated device deposited with the antireflection layer in converting photon energy to electrical energy was studied using a solar simulator under 1 sun condition. The ability to collect charge carriers of the anti-reflection coated device as a function of wavelength was also studied using quantum efficiency measurement.
Analysis of transient and tertiary creep behavior of Titanium modified 14Cr-15Ni stainless steel after cold working
Authors: Yadav Hari Krishan , Ballal A R , Thawre M M , Vijayanand V D
Published: January 2020

Characteristic of transient and tertiary creep behavior of ten, twenty, thirty, and forty percent cold worked indigenously developed Titanium modified 14Cr-15Ni stainless steel at 700 °C and various stress levels have been assessed. Small primary creep region followed by secondary creep and then substantial tertiary creep regions were exhibited by all steels. Creep parameters like transient strain and rate of exhaustion of transient creep in Garofalo equation and tertiary strain and rate of acceleration of tertiary creep in modified Dobes and Cadek equation have been extensively studied. The relationships among exhaustion rate of transient creep, acceleration rate of tertiary creep, and minimum creep rate revealed the prevailing theory of first order reaction rate during transient and tertiary creep deformation of the Titanium modified 14Cr-15Ni stainless steel. The exhaustion rate of transient creep decreased, whereas tertiary creep parameter decreased as the amount of cold work increased. Creep damage tolerance parameter indicated that necking, precipitate coarsening, and recovery of substructures are dominant creep damage mechanisms in the Titanium modified 14Cr-15Ni stainless steel.
Thermal analysis, microstructure and performance of AA6063 aluminum alloy casting with Ag and Fe additions
Authors: Tash Mahmoud , Khalifa Waleed
Published: January 2020

This article aims to investigate the microstructure, mechanical properties, wear and corrosion resistance of the grain refined AA6063 Aluminum Alloy Casting with added Ag and Fe. Thermal analysis was used to evaluate the influence of Ag and Fe addition. Reactions are observed during the solidification due to the formation of the α-Al dendritic network, followed by the precipitation of the Al8Fe2Si, transformation of Al8Fe2Si into Al5FeSi and/or precipitation of Al5FeSi intermetallic, and finally, the precipitation of small dark particles Mg2Si. Microstructure was examined using optical microscopy, Image analysis and scanning electron microscopy. Hardness, tensile properties, wear and corrosion resistance were evaluated for the as-cast conditions. Line scans for Ag, Fe, Si, Cu and Al were obtained from the various as cast samples using Energy-dispersive x-ray spectroscopy (EDX) facilities. The results reveal that different intermetallic phases can be formed. These phases are rich in Si, Fe, Mg and Ag. Additionally, AA6063 aluminum alloy casting with added 0.7–0.85 wt% Ag and 0.25–0.95 wt% Fe showed high wear and corrosion resistance response respectively. The wear and corrosion resistance of the AA6063 aluminum alloys with added Ag and Fe resulted were remarkably improved especially at 0.7 wt% Ag addition.
Improved Recognition of Hematogones From Precursor B-Lymphoblastic Leukemia by a Single Tube Flow Cytometric Analysis
Authors: Don Michelle D , Lim Washington , Lo Amanda , Cox Brian , Huang Qin , Kitahara Sumire , Lopategui Jean , Alkan Serhan
Published: January 2020

Objectives

To improve diagnostic accuracy in differentiating hematogones from leukemic blasts in cases of precursor B-lymphoblastic leukemia/lymphoma (B-ALL), particularly those that are posttreatment or after bone marrow transplant, and to provide an algorithmic approach to this diagnostic challenge.

Methods

A seven-color antibody panel including CD10, CD19, CD45, CD38, CD34, CD58, and CD81 was generated to assess the feasibility of a single tube panel and provide an algorithmic approach to distinguish hematogones from B-ALL. Fifty-three cases were analyzed, and results were correlated with histology and ancillary studies.

Results

There was a significant difference in mean fluorescent intensity (MFI) for CD81 and CD58 when comparing hematogones and B-ALL populations (P < .001). B-ALL cases had a mean (SD) MFI of 24.6 (27.5; range, 2-125) for CD81 and 135.6 (72.6; range, 48-328) for CD58. Hematogones cases had a mean (SD) MFI of 70.2 (19.2; range, 42-123) for CD81 and 38.8 (9.4; range, 23-58) for CD58.

Conclusions

The flow cytometry panel with the above markers and utilization of the proposed algorithmic approach provide differentiation of hematogones from B-ALL. This includes rare cases of hematogones and B-ALL overlap where additional ancillary studies are necessary.
Cross-Cultural Comparison of Rural Healthy Adults: Russian and American Groups
Authors: Melikyan Zarui A , Puente Antonio E , Agranovich Anna V
Published: January 2020

Objective

The Russian-speaking population is among the largest European-born in the U.S., yet Russian-American cross-cultural research is scarce. Two studies compared neuropsychological test performance in Russian and American urban adults. However, rural populations of the two nations have never been compared. Cross-cultural neuropsychological differences in rural populations might present differently than in urban dwellers. The present study provides a cross-sectional comparison of neuropsychological test performance in Russian and American rural adults.

Methods

Neuropsychological test performance of 51 American (67% female) and 52 Russian (60% female) healthy rural adults age 18–89 was compared using t-test with Bonferroni correction for education-adjusted z-scores for the following tests: Rey Complex Figure Test (RCFT), Rey Auditory Verbal Learning Test (RAVLT), Trail Making Test A and B (TMT A&B), Stroop Neuropsychological Screening Test, Benton Judgment of Line Orientation Test (JLO), Brief Visuospatial Memory Test-Revised (BVMT-R), Color Trails Test 1 and 2 (CTT 1&2), WMS-IV Logical Memory Test (LMT), WAIS-IV Digit Span Forward (DSF) and Backward Test (DSB), and Symbol Digit Modalities Test (SDMT).

Results

Age and sex distribution did not differ in the two groups, but the Russian group was more highly educated. The American group outperformed the Russian group on TMT B, CTT 2, recognition trials of RCFT, BVMT-R, LMT, and on DSF.

Conclusions

Cultural differences in attitudes to timed activities, experience with timed tests and multiple-choice format, attention to details, and length of digit-words that put differential demand on short-term memory in Russian and in English may mediate observed between-group differences.
Holocene changes in the distributions of Asian and European badgers (Carnivora: Mustelidae: Meles) inferred from ancient DNA analysis
Authors: Kinoshita Emi , Kosintsev Pavel A , Abramov Alexei V , Solovyev Vyacheslav A , Saveljev Alexander P , Nishita Yoshinori , Masuda Ryuichi
Published: January 2020

Although the present-day distributional boundary between the European badger (Meles meles) and the Asian badger (Meles leucurus) is around the Volga River, studies of ancient bone remains have indicated changes in the distribution of M. meles and M. leucurus in the Urals–Volga region during the Holocene. To examine past changes in distribution using genetic data, changes in genetic diversity, and the relationships of Holocene to modern populations, we sequenced ~150 bp of the mitochondrial DNA control region from the 44 ancient badger remains excavated from European Russian, Ural and Western Siberian sites, and we detected 12 haplotypes. Our study revealed Holocene changes in the distributional boundary between these badger species. Meles meles inhabited the Ural Mountains east of the Volga River in the Early Holocene, whereas M. leucurus expanded its distribution westwards, starting ~2500 years ago. Thereafter, M. leucurus rapidly replaced M. meles in the region between the Urals and the Volga, resulting in the present-day boundary in the Volga–Kama region. Among the 12 haplotypes detected, three for M. leucurus and four for M. meles were identical to partial sequences of haplotypes detected in modern populations, indicating considerable genetic continuity between Holocene and modern populations.
Inactivation of TRP53, PTEN, RB1, and/or CDH1 in the ovarian surface epithelium induces ovarian cancer transformation and metastasis
Authors: Shi Mingxin , Whorton Allison E , Sekulovski Nikola , Paquet Marilène , MacLean James A , Song Yurong , Van Dyke Terry , Hayashi Kanako
Published: January 2020

Ovarian cancer (OvCa) remains the most common cause of death from gynecological malignancies. Genetically engineered mouse models have been used to study initiation, origin, progression, and/or mechanisms of OvCa. Based on the clinical features of OvCa, we examined a quadruple combination of pathway perturbations including PTEN, TRP53, RB1, and/or CDH1. To characterize the cancer-promoting events in the ovarian surface epithelium (OSE), Amhr2cre/+ mice were used to ablate floxed alleles of Pten, Trp53, and Cdh1, which were crossed with TgK19GT121 mice to inactivate RB1 in KRT19-expressing cells. Inactivation of PTEN, TRP53, and RB1 with or without CDH1 led to the development of type I low-grade OvCa with enlarged serous papillary carcinomas and some high-grade serous carcinomas (HGSCs) in older mice. Initiation of epithelial hyperplasia and micropapillary carcinoma started earlier at 1 month in the triple mutations of Trp53, Pten, and Rb1 mice as compared to 2 months in quadruple mutations of Trp53, Pten, Rb1, and Cdh1 mice, whereas both genotypes eventually developed enlarged proliferating tumors that invaded into the ovary at 3–4 months. Mice with triple and quadruple mutations developed HGSC and/or metastatic tumors, which disseminated into the peritoneal cavity at 4–6 months. In summary, inactivation of PTEN, TRP53, and RB1 initiates OvCa from the OSE. Additional ablation of CDH1 further increased persistence of tumor dissemination and ascites fluid accumulation enhancing peritoneal metastasis.
Drug-drug Interactions Among Thai Transgender Women Living with Human Immunodeficiency Undergoing Feminizing Hormone Therapy and Antiretroviral Therapy: The iFACT Study
Authors: Hiransuthikul Akarin , Himmad Linrada , Kerr Stephen J , Janamnuaysook Rena , Dalodom Theera , Phanjaroen Kannapat , Pankam Tippawan , Kongkapan Jiratchaya , Mills Stephen , Vannakit Ravipa , Phanuphak Praphan , Phanuphak Nittaya
Published: January 2020

Background

Drug-drug interactions between feminizing hormone therapy (FHT) and antiretroviral therapy (ART) are a major concern among transgender women (TGW), which may lead to suboptimal ART adherence and inappropriate FHT dosage. To evaluate potential drug-drug interactions between FHT and ART, we performed intensive measurements of the pharmacokinetic (PK) parameters of blood tenofovir (TFV), efavirenz (EFV), and estradiol (E2).

Methods

Twenty TGW with newly diagnosed human immunodeficiency virus (HIV) infection were enrolled. FHT (E2 valerate 2 mg/d and cyproterone acetate 25 mg/d) was prescribed at baseline until week 5 and restarted at week 8. ART (TFV disoproxil fumarate/emtricitabine/EFV at 300/200/600 mg) was initiated at week 3. The E2 PK parameters were measured intensively at weeks 3 (without ART) and 5 (with ART), and TFV and EFV PK parameters were measured intensively at weeks 5 (with FHT) and 8 (without FHT).

Results

The median (interquartile range) age and body mass index were 25.5 (22.5–31.0) years and 20.6 (19.3–23.1) kg/m2, respectively. The differences in geometric mean ratios between weeks 3 and 5 were as follows for E2 area under the curve, maximum concentration, and concentration at 24 hours (C24), respectively: 0.72 (90% confidence interval, .64–.81; P < .001), 0.81 (.72–.92; P = .006), and 0.64 (.50–.83; P = .004). The differences in geometric mean ratios between weeks 5 and 8 were as follows for TFV AUC, TFV C24, and EFV C24: 0.86 (90% confidence interval, .80–.93; P = .002), 0.83 (.75–.93; P = .006), and 0.91 (.85–.97; P = .02).

Conclusions

Among HIV-positive TGW, E2 PK parameters were significantly lower in the presence of TFV disoproxil fumarate/emtricitabine/EFV, and some TFV and EFV PK parameters were lower in the presence of FHT. Further studies should determine whether these reductions are clinically significant and whether they occur with other FHT or ART regimens.
Does This Patient Need Blood Cultures? A Scoping Review of Indications for Blood Cultures in Adult Nonneutropenic Inpatients
Authors: Fabre Valeria , Sharara Sima L , Salinas Alejandra B , Carroll Karen C , Desai Sanjay , Cosgrove Sara E
Published: January 2020

Guidance regarding indications for initial or follow-up blood cultures is limited. We conducted a scoping review of articles published between January 2004 and June 2019 that reported the yield of blood cultures and/or their impact in the clinical management of fever and common infectious syndromes in nonneutropenic adult inpatients. A total of 2893 articles were screened; 50 were included. Based on the reported incidence of bacteremia, syndromes were categorized into low, moderate, and high pretest probability of bacteremia. Routine blood cultures are recommended in syndromes with a high likelihood of bacteremia (eg, endovascular infections) and those with moderate likelihood when cultures from the primary source of infection are unavailable or when prompt initiation of antibiotics is needed prior to obtaining primary source cultures. In syndromes where blood cultures are low-yield, blood cultures can be considered for patients at risk of adverse events if a bacteremia is missed (eg, patient with pacemaker and severe purulent cellulitis). If a patient has adequate source control and risk factors or concern for endovascular infection are not present, most streptococci or Enterobacterales bacteremias do not require routine follow-up blood cultures.
Dare to Diverge: Time for Administrative Law in Hong Kong to Stand on Its Own Two Feet
Authors: Thomson Stephen
Published: January 2020

Hong Kong’s system of administrative law has drawn strength and durability from its English counterpart, on which it was heavily modelled. Too often, however, there is a slavish acceptance of the pre-eminence of English law and a tendency to conservativism and a lack of innovation. This article argues that Hong Kong courts and legislators must dare to diverge from English law where an alternative path would prove more credible or appropriate. Three prisms are deployed through which to argue that a misplaced emulation of English law can result in a poor legal framework. First, it is shown that a failure to properly conceptualize error of law as a ground of judicial review has resulted in a ground that, locally, is in a state of incoherence and disarray and that the admission or non-admission of a distinction between jurisdictional and non-jurisdictional errors urgently requires clarification from the Court of Final Appeal. Second, it is proposed that the English-inspired incorporation of a specific time limit in the rules for applying for judicial review should be abolished in the interests of access to justice and legal certainty, drawing on the experience of jurisdictions such as New Zealand, Canada, and Scotland. Finally, it is explained why the antiquated system of administrative tribunals in Hong Kong, redolent of the unreformed English tribunal system of decades past, needs comprehensive structural and procedural redesign. Courts and legislators must dare to diverge in these areas, with Hong Kong’s administrative law standing on its own two feet, where minds are focused on a genuine, locally crafted improvement of standards prevailing in administrative law and public administration.
Establishment of a reference interval for beta 2-microglobulin in cerebrospinal fluid with use of two commercial assays
Authors: Lutz Charles T , Cornell Steven H , Goeken James A
Published: January 2020

Increased concentrations of beta 2-microglobulin in cerebrospinal fluid have been used to detect central nervous system involvement with metastatic cancer and with neurological complications of AIDS. However, no adequate reference interval study has been reported for beta 2-microglobulin in cerebrospinal fluid. We established a reference interval with both the Abbott IMx microparticle enzyme-linked immunoassay (EIA) (0.6-2.0 mg/L) and the Pharmacia beta 2-micro EIA 96 method (0.8-2.2 mg/L) for beta 2-microglobulin in cerebrospinal fluid. The two methods correlate well, with the latter method giving slightly higher values. beta 2-Microglobulin increases with age in adults by about 0.1 mg/L every 7.5 years, with no significant difference between genders.
Logistic-regression model for assessing portal hypertension by measuring hyaluronic acid (hyaluronan) and laminin in serum
Authors: Kropf Jürgen Krop , Gressner Axel M , Tittor Wolfgan
Published: January 2020

We earlier observed a positive correlation between portal venous pressure (PVP) and the concentration of laminin in serum. Here we investigated whether the diagnostic efficacy could be improved by considering additional analytes and application of multivariate statistical analysis. In 102 patients with fibrotic liver disease of various etiologies we measured PVP as the gradient of the wedged and free hepatic venous pressures and determined the concentrations of hyaluronic acid and laminin in serum. Regression coefficients established by logistic regression in this group were subsequently used to predict portal hypertension (PVP greater than mmHg) in an independent group of 45 patients. By comparison with the known PVP, we obtained a sensitivity of 0.83 (confidence interval: 0.63-0.93) and a specificity of 0.82 (0.61-0.93) for diagnosis of portal hypertension by means of the concentrations of hyaluronic acid and laminin in serum. Application of the model is suggested as a tool for pre-screening and monitoring patients to be subjected to assessment of portal hypertension.
Radioimmunoassay of inhibin based on synthetic human inhibin alpha-chain peptide
Authors: Sinosich M J , Sieg S , Zakher A , Ling N , Saunders D M , Rosenwaks Z , Hodgen G D
Published: January 2020

Polyclonal rabbit antisera were produced against cyclic human inhibin [(Cys6, Tyr7) alpha-(6-30)NH2] peptide, covalently conjugated to bovine serum albumin. The tyrosine residue introduced at position 7 facilitated the oxidative incorporation of radiolabel (125I) to yield a tracer with specific activity of 73.9 Ci/g. These reagents were used to develop a homologous equilibrium radioimmunoassay for human inhibin, with polyethylene glycol, 200 g/L, serving as the separation phase. At a detection limit of 2 micrograms/L (n = 7), immunoactive inhibin was detectable in human pre-ovulatory follicular fluid (128 micrograms/L), seminal plasma (2374 micrograms/L), amniotic fluid (66 micrograms/L), and placental extract (347 micrograms/L). We also demonstrated inhibin immunoreactivity in biological fluids from other mammalian species: macaque, chimpanzee, porcine, and bovine, but not rodent (guinea pig). Although the antisera were raised against a nonbioactive inhibin peptide, immunoglobulins fractionated on Protein A-Sepharose neutralized the bioactivity of human ovarian inhibin. Further characterization of inhibin immuno- and bioactivity was undertaken with immobilized heparin, divalent metal cations, and dye ligands. Only heparin-Sepharose distinguished between immuno- and bioactive inhibin.
Monitoring treatment of alcoholic liver disease: evaluation of various severity indices
Authors: Blake Joan , Orrego Hector
Published: January 2020

Monitoring the effectiveness of treatment sfor alcoholic liver disease involves the use of variables that have prognostic significance and are unaffected by the treatment in unspecific ways. Here we review the value of histological and functional variables for this purpose. We conclude that histological variables, although important in defining the characteristics of the sample, have several practical problems. The functional variables are most effective when used in combinations, e.g., in global indices such as the Combined Clinical and Laboratory Index, the Child-Turcotte-Pugh Index, or the Cox model. In situations involving mortality and dropouts, functional indices cannot be used to measure changes in severity; in such cases, mortality might be the only measure for assessing the effectiveness of a treatment. In clinical trials, it is essential to determine the risk of a Type II error, to monitor compliance and drinking, and to trace appropriately all the patients who were not compliant or who dropped out of the trial.
Novel application of streptavidin-hapten derivatives as protein-tracer conjugate in competitive-type immunoassays involving biotinylated detection probes
Authors: Khosravi M J , Morton R C
Published: January 2020

To investigate the use of streptavidin-hapten derivatives as potential protein-tracer conjugates for competitive-type immunoassays, we labeled streptavidin with cortisol and compared biotin-binding activity of the conjugates with that of unlabeled streptavidin. In this model system, streptavidin labeled with one to approximately 17 cortisol molecules retained its capability to cross-link a biotinylated protein on microtiter wells to a biotin-based general detection reagent developed for time-resolved fluorometry. Compared with unlabeled streptavidin, there was no reduction in the binding activity of the conjugate carrying as many as 2.6 cortisol molecules per molecule of streptavidin. Conjugation ratios greater than 4.4 showed a slight decrease in binding activity, presumably because of the aggregate formation evident at these labeling ratios. As expected, the conjugates were also capable of linking a solid-phase-bound anti-cortisol monoclonal antibody to the biotinylated detection reagent. The fluorescence signal generated increased almost linearly with increasing conjugation ratios from about three to nine cortisol molecules per molecule of streptavidin. At greater ratios, the assay response plateaued. The calibration curves obtained were typical for competitive-type immunoassays when the conjugates were incorporated in a cortisol assay based on a second-antibody immobilization approach.
Investigation of xurinary crystals by Fourier transform infrared microscopy
Authors: Daudon M , Marfisi C , Lacour B , Bader C
Published: January 2020

Although crystalluria is generally considered a normal finding, sometimes it gives evidence of renal disturbance. Thus, detection and identification of urinary crystals may provide useful data for understanding the etiology of mechanism of the disorder. Light microscopy may be not sufficient to accurately identify the crystals. We investigated the ability of Fourier transform infrared microscopy (FTIRM) to identify isolated crystals of clinical interest. Twenty-five urine samples presenting crystalluria were tested because of their unusual aspect. We successfully identified 16 compounds and showed that crystals with the same apparent morphology can be composed of different substances. Moreover, an unexpected structure may be an insoluble phase of a drug metabolite. We conclude that FTIRM is a good technique for investigating urinary crystals of clinical interest.
HPLC with enzymatic detection as a candidate reference method for serum creatinine
Authors: Linnet K , Bruunshuus I
Published: January 2020

We present a candidate Reference Method for determining the concentration of serum creatinine. The method is based on HPLC combined with enzymatic determination. Creatinine plus 14[C]creatinine is extracted by cation-exchange chromatography, subjected to reversed-phase HPLC, and finally quantified enzymatically. Enzymatic measurement ensures no interference from co-eluting compounds, which has been a problem for some reported HPLC assays relying on ultraviolet detection. The average corrected recovery was 100.1% (SEM = 1.1%; n = 15). The accuracy was verified by assaying five sera with target values determined by isotope dilution mass spectrometry. The total interassay CV was less than or equal to 2.5%. We applied the method to study the specificity of HPLC-ultraviolet detection, using 72 plasma samples from hospitalized patients; no interference was noted. Thus, HPLC-ultraviolet detection appears to be specific, provided that sample cleanup is based on cation-exchange chromatography. Our diode-array detector studies of peak homogeneity supported this conclusion. Still, combined HPLC-enzymatic determination ensures even greater accuracy, ranking close to that by isotope dilution mass spectrometry.
Determination of silver in blood, urine, and tissues of volunteers and burn patients
Authors: Wan A T , Conyers R A , Coombs C J , Masterton J P
Published: January 2020

Silver sulfadiazine cream (SSD) has been used successfully in the management of burn wound sepsis. Silver deposition has been found in the skin, gingiva, cornea, liver, and kidney of patients treated with this cream, causing argyria, ocular injury, leukopenia, and toxicity in kidney, liver, and neurologic tissues. Monitoring concentrations of silver in blood and urine of patients receiving this treatment has become necessary, but sensitive and suitable methods adaptable to a clinical laboratory are still needed. We have developed a flameless thermal atomic absorption spectrophotometric method to measure silver concentrations in blood, urine, and other tissues. The detection limit is 0.4 microgram/L; the within-run precisions (CV) are 5.16%, 3.83%, and 2.79% for concentrations of 5, 13.5, and 42 micrograms/L, respectively; and the between-run precisions are 4.3% and 3.2% for concentrations of 13.5 and 42 micrograms/L. The concentrations of silver in blood, urine, liver, and kidney of subjects without industrial or medicinal exposure are less than 2.3 micrograms/L, 2 micrograms/day, 0.05 microgram/g wet tissue, and 0.05 microgram/g wet tissue, respectively. In SSD cream-treated burn patients, plasma concentrations may be as great as 50 micrograms/L within 6 h of treatment and can reach a maximum of 310 micrograms/L. Silver in urine is detectable after one day of treatment and may reach a maximum of 400 micrograms/day. After absorption, silver was found to be deposited in various tissues. Tissue silver concentrations in one burn patient who died of renal failure after eight days of treatment were 970, 14, and 0.2 micrograms/g wet tissue in cornea, liver, and kidney, respectively.
Glucocorticoid receptors in normal leukocytes: effects of age, gender, season, and plasma cortisol concentrations
Authors: Tanaka H , Akama H , Ichikawa Y , Homma M , Oshima H
Published: January 2020

We measured glucocorticoid receptors (GR) in mononuclear leukocytes (MNL) isolated from peripheral blood of 145 apparently healthy volunteers (86 men and 59 women). An age-related decrease in the number of GR was suggested between subjects younger than 20 years and elderly subjects; there was no apparent seasonal variation in GR. Gender difference in the number of GR was not significant, although women showed slightly fewer GR. Eight patients with dermatomyositis/polymyositis were examined to determine whether the number of GR in MNL could be down-regulated by their cognate ligands. The number of GR in MNL from these patients was significantly decreased one month after the initiation of prednisolone therapy. However, in normal subjects, the GR in MNL did not demonstrate circadian variation, in contrast to concentrations of plasma cortisol.
Quantification of serum amyloid P by enzyme-linked immunosorbent assay
Authors: Saïle R , Kandoussi A , Deveaux M , Descamps J , Hachulla E , Cachera C
Published: January 2020

This enzyme-linked immunosorbent assay procedure for quantifying serum amyloid P (SAP) in human plasma makes use of affinity-purified polyclonal antibodies to SAP in a "sandwich"-type format. The procedure is sensitive, reproducible, simple, and easily automatable. Results correlate well with those by a rocket immunoelectrophoresis method performed with the same antibodies. Sera from apparently normal individuals had a mean SAP content of 44.17 mg/L and increased with age.
Using mutagenic polymerase chain reaction primers to detect carriers of familial defective apolipoprotein B-100
Authors: Motti C , Funke H , Rust S , Dergunov A , Assmann G
Published: January 2020

Familial defective apolipoprotein (apo) B-100 is a genetic trait characterized by an Arg----Gln substitution in position 3500 of the apo B sequence. This genetic defect is associated with greatly increased concentrations of plasma cholesterol and may thus increase the risk of developing premature atherosclerotic disease. We describe here the use of mutagenic polymerase chain reaction primers, which greatly facilitate identification of carriers of this mutation. Moreover, we demonstrate that this method may also be used for determining the phase between two polymorphic sites. Using apo B-100 as an example we located on different chromosomes the defect in codon 3500 and a mutation in codon 3611, which produces another Arg----Gln change in the encoded apo B-100 amino acid sequence, in two probands heterozygous for both mutations.
Measuring rheumatoid factor in nonrheumatoid subjects: immunoturbidimetric assay, latex slide test, and enzyme-linked immunosorbent assay compared
Authors: Ailus K , Melamies L , Tuomi T , Palosuo T , Aho K
Published: January 2020

Previous studies of patients with rheumatoid arthritis (RA) have shown a good correlation between results from immunoturbidimetric assays of rheumatoid factor (RF) and latex fixation tests. To extend the research to non-RA subjects, we tested sera from 1000 pregnant women, half each in the first and third trimesters. By turbidimetry, 24 non-RA sera were regarded as positive for RF (greater than or equal to 20 int. units/mL) and 18 sera as borderline (15-19 int. units/mL). By the latex fixation test, 28 non-RA sera gave a clear reaction (positive) and 17 sera a weak reaction (borderline). The association between the tests was statistically highly significant (P less than 0.001). All sera with positive and borderline reactions were tested by enzyme-linked immunosorbent assay for RF isotypes, together with a random subsample of about one-sixth of the original serum samples. Positive RF results by immunoturbidimetry were predominantly due to the presence of IgM-RF. In contrast to some earlier findings, we saw no difference in the prevalence of positive RF reactions between sera from the first and third trimesters.
Abnormal sodium metabolism and plasma renin activity (renal renin secretion) and the vasoconstriction volume hypothesis: implications for pathogenesis and treatment of hypertension and its vascular consequences (heart attack, stroke)
Authors: Laragh J H , Sealey J E
Published: January 2020

Arterial hypertension is sustained by either of two long-term mechanisms of arteriolar vasoconstriction or by an inappropriate reaction between them. One mechanism is renin-mediated, the other is related to antecedent renal sodium retention. The plasma renin value directly reflects the presence and degree of renin-mediated vasoconstriction, and, inversely, defines the predominance of sodium-related vasoconstriction. A hypotensive response, or lack of it, to angiotensin-converting enzyme inhibitor is similarly informative. Because the normal kidney exposed to high arterial pressure and normal salt intake will reduce its renin secretion to near zero, any renin secretion in a hypertensive setting can be considered abnormal. Typically, high-renin hypertensive patients are more vasoconstricted than low-renin patients with similar blood pressures. The intense vasoconstriction leads to relative hypovolemia, hemoconcentration, hyperviscosity, postural hypotension, and in severe forms even to acrocyanosis, all of which are dramatically reversed with anti-renin therapy. Conversely, low-renin equally hypertensive patients have relatively more sodium volume and are less vasoconstricted; they are generally responsive to natriuretic drugs (e.g., diuretics or calcium antagonists) and appear relatively protected from vascular sequelae such as stroke and heart attack. These observations provide a new means for evaluating prognosis and a basis for mechanistically differentiating and treating hypertensive patients, allowing increasingly simpler and more-specific long-term therapies.
The role of laboratory testing in the diagnosis of renovascular hypertension
Authors: Pickering T G
Published: January 2020

The diagnosis of renovascular hypertension depends heavily on laboratory tests. There is no universally applicable screening test, and it should be actively sought only in patients with clinical clues suggested by the history, physical examination, and routine laboratory testing. Hyperreninemia is a characteristic finding, and acute blockade of the renin system forms the basis of diagnostic tests such as the oral captopril test and captopril renography. Other abnormal laboratory findings include hypokalemia, proteinuria, and azotemia exacerbated by angiotensin-converting enzyme inhibitors.
Steroid characteristics of mineralocorticoid adrenocortical hypertension
Authors: Biglieri E G , Kater C E
Published: January 2020

Adrenocortical causes of hypertension are established by examining the mineralocorticoid hormones produced in the zona glomerulosa and zona fasciculata. In the zona glomerulosa, aldosterone excess leads to hypertension, hypokalemia, and suppressed plasma renin activity, with increased concentrations of urinary aldosterone (either as the 18-glucuronide or free aldosterone) as an index of its production. Identifying a tumor by computed tomography scan verifies the diagnosis of a correctable lesion. If no tumor is found, several maneuvers are used to identify primary adrenal hyperplasia, a disorder with autonomous aldosterone production, for which reduction of adrenal mass is curative. The zona fasciculata has two major pathways: the 17-deoxy pathway, where deoxycorticosterone (DOC) and corticosterone are the significant steroids, and the 17-hydroxy pathway, which leads to cortisol production. Tumors of the 17-deoxy pathway, DOC-producing adenomas, have increased concentrations of DOC and its precursor steroids, normal concentrations of cortisol, and suppression of aldosterone production secondary to suppression of the renin system. Two enzymatic defects in the zona fasciculata, 11 beta- and 17 alpha-hydroxylase deficiency, can be first readily identified by the virilization in the former, hypogonadal features in the latter. Steroid patterns are diagnostic. DOC is produced in excess in both deficiencies and is the cause of the hypertension. Deficient or impaired 11 beta-hydroxy steroid dehydrogenase in the apparent mineralocorticoid excess syndrome or after licorice ingestion retards the conversion of cortisol to inactive cortisone in the kidney, leading to mineralocorticoid hypertension; this leads to suppression of the renin system and subsequently of aldosterone.
Clinical evaluation and differential diagnosis of the individual hypertensive patient
Authors: Mueller F B , Laragh J H
Published: January 2020

This paper attempts to define the theory and practice of a modern approach to the initial workup of the patient with hypertension. The process includes a complete general medical evaluation along with special measures to enable the fullest characterization and clinical differentiation of the disease. The initial workup aims to (a) establish that the hypertension is sustained and should be treated; (b) identify all definable and curable causes for the hypertension; (c) identify the presence and degree of attendant risk factors such as smoking, alcohol use, obesity, diabetes, and abnormal lipid metabolism; (d) characterize the hypertension in terms of its pathophysiology; and (e) assess the presence and degree of target organ damage to the heart, brain, and kidneys. Because all diastolic hypertension is due to arteriolar vasoconstriction, a fundamental strategy of this process is to distinguish between renin-mediated and sodium-related vasoconstrictive forces and to evaluate which is preponderant. The chief instruments of this strategy are the renin-sodium profile and the response of plasma renin activity and blood pressure to specific antirenin system drugs. The captopril test, an important protocol in making this distinction, is primarily a powerful screening tool for confirming the possible presence or absence of curable renovascular disease or curable primary aldosteronism. That renin profiling cannot accurately discriminate between the contributions of either the renin or sodium-volume factors in that large fraction of medium-renin patients is not a viable reason for not performing the test. The test has its greatest strength for identifying sizable numbers of otherwise unrecognizable patients with very high or very low renin concentrations who might have curable disorders and who likely reflect different pathophysiologic vasoconstrictive mechanisms for which entirely different drug therapies are appropriate. However, the baseline renin test is also useful for assessing prognosis and the likelihood of a heart attack and it is valuable for deciding whether to use an anti-renin system drug (for medium and high renin concentrations) as opposed to natriuretic agents (low-renin patients) such as a diuretic or calcium antagonists as the primary step. In our present state of knowledge, the basic diagnostic biochemical workup includes the renin-sodium profile and the 24-h urinary sodium, potassium, and microalbumin excretion rates. This package is further enriched by baseline electrocardiography and echocardiography and the evaluation of glucose and lipid patterns.(ABSTRACT TRUNCATED AT 400 WORDS)
Heterogeneity among hypertensive subjects: a tool for clinical decision-making
Authors: Alderman M H
Published: January 2020

Current antihypertensive treatment strategy tends to approach all patients similarly, with decision to treat, the goal of treatment, and medication use based largely on blood pressure measurement. Clearly, it would make far more sense if a management strategy could be developed that was not solely dependent on measurement of blood pressure, but rather reflected a clearer understanding of individual likelihood of adverse outcome, the nature of blood pressure control, and the importance of associated clinical and biological characteristics. New tools make it possible to accurately assess the status of the heart, kidney, and blood vessels, both as a guide to the need for therapy and as a measure of treatment progress when the treatment is used. New understanding of the vasoconstrictor and volume contributions to blood pressure control coupled with a rich armamentarium of therapeutic agents make it possible to tailor therapy more appropriately. Finally, growing awareness of the contribution of concomitant risk factors has made it clear that overall success depends on attention to the whole patient.