bluuebunny/crossref_metadata_2025 huggingface dataset:
A stochastic method to propagate uncertainties along large cores deterministic calculations
Authors: Volat Ludovic , Gastaldi Bernard , Santamarina Alain
Published: June 2018

Deterministic uncertainty propagation methods are certainly powerful and time-sparing but their access to uncertainties related to the power map remains difficult due to a lack of numerical convergence. On the contrary, stochastic methods do not face such an issue and they enable a more rigorous access to uncertainty related to the PFNS. Our method combines an innovative transport calculation chain and a stochastic way of propagating uncertainties on nuclear data: first, our calculation scheme consists in the calculation of assembly self-shielded cross sections and a pin-by-pin flux calculation on the whole core. Validation was done and the required CPU time is suitable to allow numerous calculations. Then, we sample nuclear cross sections with consistent probability distribution functions with a correlated optimized Latin Hypercube Sampling. Finally, we deduce the power map uncertainties from the study of the output response functions. We performed our study on the system described in the framework of the OECD/NEA Expert Group in Uncertainty Analysis in Modelling. Results show the 238U inelastic scattering cross section, the 235U PFNS, the elastic scattering cross section of 1H and the 56Fe cross sections as major contributors to the total uncertainty on the power map: the power tilt between central and peripheral assemblies using COMAC-V2 covariance library amounts to 5.4% (1σ) (respectively 7.4% (1σ) using COMAC-V0).
Efficient use of Monte Carlo: the fast correlation coefficient
Authors: Sjöstrand Henrik , Asquith Nicola , Helgesson Petter , Rochman Dimitri , Marck Steven van der
Published: June 2018

Random sampling methods are used for nuclear data (ND) uncertainty propagation, often in combination with the use of Monte Carlo codes (e.g., MCNP). One example is the Total Monte Carlo (TMC) method. The standard way to visualize and interpret ND covariances is by the use of the Pearson correlation coefficient,

[see formula in PDF]

where x or y can be any parameter dependent on ND. The spread in the output, σ, has both an ND component, σND, and a statistical component, σstat. The contribution from σstat decreases the value of ρ, and hence it underestimates the impact of the correlation. One way to address this is to minimize σstat by using longer simulation run-times. Alternatively, as proposed here, a so-called fast correlation coefficient is used,

[see formula in PDF]

In many cases, cov(xstat; ystat) can be assumed to be zero. The paper explores three examples, a synthetic data study, correlations in the NRG High Flux Reactor spectrum, and the correlations between integral criticality experiments. It is concluded that the use of ρ underestimates the correlation. The impact of the use of ρfast is quantified, and the implication of the results is discussed.
Water residence time in the Włocławek dam reservoir (the Vistula river, Poland) affects its macrozoobenthos structure
Authors: Mimier Daria , Żbikowska Elżbieta , Żbikowski Janusz
Published: June 2018

The aim of our study was to compare the macrozoobenthos structure as well as water and organic matter content of the bottom sediments of two hydrologically different zones of a strongly fluvial the Włocławek Dam Reservoir. Samples were collected from the Włocławek Dam Resevoir at six sites. Three of them were located in the upper, rheolimnic part (URP) of the reservoir and three others in its lower, limnetic part (LLP). Water transparency, sediment water content and organic matter content in the sediments were higher in the LLP. The higher number of taxa and diversity of macrozoobenthos were found in the URP of the reservoir. The density of bottom fauna was slightly higher in the LLP (90,990 ind. m−2) than in the UPR (73,486 ind.  m−2), while the significantly higher biomass of macrozoobenthos was found in the URP of the reservoir (2314 g · m−2) than in the LLP (336 g · m−2). The dominant taxa of Oligochaeta and Chironomidae larvae did not show significant differences in the density between both zones. Some taxa were found only in the URP. In this zone, significantly higher densities of other taxa were observed. The only species with greater abundance in the LLP wasPotamothrix hammoniensis(Oligochaeta). Due to the very short water residence time, the differences in the parameters under study between the URP and the LLP of the reservoir were smaller as well as the abundance of the macrozoobenthos was distinctly higher than in other reservoirs.
The Effect of Mixing and Curing Sea Water on Concrete Strength at Different Ages
Authors: Guo Qingyong , Chen Lei , Zhao Huijian , Admilson Jorge , Zhang Wensong
Published: June 2018

In the research, the effects of sea water for mixing, curing on the gain in strength of different grades of concrete was investigated. A total of 192 concrete cubes were tested for their compressive strength. The study shows that sea water affects the rate of gain in strength of concrete when used for mixing or curing. The strength of concrete made by using sea water was observed to be decreased by about 15% as compared to the similar concrete specimens made and cured with fresh water at 90 days. The concrete with higher strength showed poorer resistance against strength deterioration as compared to the lower strength concrete which used sea water for curing. And the concrete made with sea water decreased the stability of concrete properties.
A Calculation Theory of Earth Pressure Considering Microstructure of Porous Materials
Authors: Li Jun-hu , Zhang Chao , Xue Wei , Zhang Wen-chao , Xu Ri-qing
Published: June 2018

To explore a more reasonable earth pressure calculation theory, microstructure characteristics of soft clay in Hangzhou, Ningbo and Wenzhou had been observed using scanning electron microscope (SEM) and were quantitatively analysed using Image-Pro Plus (IPP) software. The relationship between porosity and contact area of soft clay was got by considering the microstructure. Combining soil lateral stress transfer principle, a calculation theory of earth pressure considering soil contact area was got. The possible reason of the differences between earth pressure and the actual monitoring earth pressure was analysis by the case.
Microstructure and Phase Composition of Titanium Coatings Plasma Sprayed with a Shroud
Authors: Zhou Hong , Liu Zhi , Luo Liancong
Published: June 2018

Excellent corrosion resistance has made titanium a preferred material for use in industry with harsh environments. Protective titanium coatings combined with cheap bulk materials are expected to enable sufficient corrosion protection and lower the cost. Plasma spray processing of titanium feedstock becomes a challenging topic of research as titanium powder particles have to experience high temperatures in the flight during the thermal spraying process in an open air environment. In this paper, plasma spraying of titanium has been carried out by using a shroud in order to shield molten particles from reacting with surrounding environment. Microstructure analyses on the titanium coatings were performed by using SEM, EDS and XRD. The results show that the shroud attachment is capable of withstanding high plasma temperatures; the as-sprayed shrouded titanium coating exhibits a similar phase composition as the pure titanium powder, and an enhanced microstructure with a lower porosity for the titanium coating plasma-sprayed with a shrouding system is observed.
Thermal state analysis of energy saving structures of cast-in-place lightweight aggregate concrete walls
Authors: Tsvetkov Nikolay , Khutornoi Andrei , Kozlobrodov Alexandr , Kolesnikova Anna , Ivanova Elena , Golovko Artem
Published: June 2018

The purpose of this paper is numerical study on the impact of location of cylindrical fillers made of insulating material on the thermal state and thermal protection properties of the corner fragment of cast-in-place lightweight aggregate external wall. Solution of spatial thermal conductivity problem was obtained and the effect of low-thermal-conductivity fillers location inside the corner fragment of a wall was analyzed using the software complex Ansys. The nature of temperature fields distribution was determined both inside the wall and in the inner corner of the structure. The method for temperature increase in the inner corner is suggested and its quantitative evaluation is performed. The effect of thermophysical and geometrical parameters of wall materials on its thermal insulation properties is analyzed.
Influence of metal frame on heat protection properties of a polystyrene concrete wall
Authors: Tsvetkov Nikolay , Khutornoi Andrei , Kozlobrodov Alexandr , Romanenko Sergei , Shefer Yuri , Golovko Artem
Published: June 2018

The use of novel thermal-efficient building materials and technologies that allow increasing the level of thermal protection of external envelope structures and reducing the time for construction are of practical interest and represent a relevant task in the conditions of rapidly changing and increasing requirements to energy efficiency of buildings. This research aims at simulating the process of spatial heat transfer in a multilayer non-uniform structure of an external cast-in-place framed wall produced from polystyrene concrete with a stay-in-place formwork. Based on the physico-mathematical model developed with the use of ANSYS and COMSOL software complexes, parametric analysis of the impact of various factors on thermal behavior of the external wall was performed with the account of heat-stressed frame elements. The nature of temperature fields distribution in a polystyrene concrete structure was defined, and its thermal protection properties were investigated. The impact of a metal frame on thermal protection properties of a wall was found to be insignificant.
Material and field impacts on cement compositions
Authors: Rubanov Aleksandr , Gorlenko Nikolay , Vergasov Vladimir
Published: June 2018

The paper studies the effect of combined field impact on cement compositions. The priority research direction involves creation of cement compositions and technologies that meet the requirements of technological availability and efficiency, environmental safety and sustainability, biocompatibility, economic efficacy and energy and resource saving. The paper proves that these criteria can be affected by material and field impacts on cement systems, which leads to considerable increase in strength of hardened cement paste, mortars and concretes. With this purpose, the paper presents detailed study on combined impact of ultrasound and magnetic field on grouting fluid of cement systems and strength of hardening systems in normal conditions. Compressive strength of cement and sand mortar was found to increase on average by 30-45%.
Stress-strain dependence and the evolution of dislocation structure in Cu-Mn polycrystalline concentrated solid solutions
Authors: Koneva Nina , Sentsova Yuliya , Trishkina Lyudmila , Cherkasova Tatiana
Published: June 2018

Deformation of metallic materials results in dislocations occurrence and accumulation, with establishment of their definite distribution (dislocation substructure). The type of dislocation substructure (DSS) defines largely resistance to deformation and fracture of materials. Quantitatively the interrelation of DSSs and resistance to deformation are studied on a limited number of alloys. Foreign literature lacks studies referring to those issues. The given paper investigates the stress-strain dependences in Cu-Mn polycrystalline solid solutions. Mn concentration in the alloys varied within the range of 10…25 at.%. Polycrystals with 10 and 240 μm mean grain size were investigated. Deformation was applied by means of tension at the velocity of 2.10-2 s-1 and the temperature of 293 K. Using transmission electron microscope at the accelerating voltage of 125 kV, microstructure of the samples was investigated when they were deformed up to various deformation degrees. The types of DSSs were defined. The connection of the deformation stage under tension with the formed types of DSS was discussed. The sequence of transition of DSSs during the process of alloys deformation was defined. Appearance of the new stage of deformation hardening is attributed to the occurrence of the new type of substructure. The occurring “new” DSS develops during the deformation process, while “the old” DSS gradually disappears. Each of the stage of plastic deformation generally has two types of DSSs. The connection of the deformation stage and the strain hardening coefficient with the DSS was defined and it was shown to possess the definite dislocation density.
Surface treatment by the ion flow from electron beam generated plasma in the forevacuum pressure range
Authors: Klimov Aleksandr , Zenin Aleksey
Published: June 2018

The paper presents research results of peculiarities of gas ion flows usage and their generation from large plasma formation (>50 sq.cm) obtained by electron beam ionization of gas in the forevacuum pressure range. An upgraded source was used for electron beam generation, which allowed obtaining ribbon electron beam with no transmitting magnetic field. Absence of magnetic field in the area of ion flow formation enables to obtain directed ion flows without distorting their trajectories. In this case, independent control of current and ion energy is possible. The influence of electron beam parameters on the parameters of beam plasma and ion flow – current energy and density – was determined. The results of alumina ceramics treatment with a beam plasma ions flow are given.
Assessment of noise parameters in elements of urban transport infrastructure
Authors: Bolshanina Taisia , Ovsiannikov Sergei
Published: June 2018

The paper considers urban road network in combination with elements of transport infrastructure which are presented as noise sources. Acoustic analysis of the level of noise produced by transport accounts only railway track spans and highways as linear sources of noise. Within the study road network elements and objects of transport infrastructure were classified; traffic interchanges and objects of transport infrastructure were presented as spatial noise source, which provides relevance of this study. The purpose of the research is development of methods for analyzing noise parameters of road networks and objects of transport infrastructure, as well as analysis of noise level in the residential territories caused by the combination of linear and spatial noise sources. The results of analysis and measurements demonstrate that evaluation of noise level caused by transport of the near-highway territory without the account of traffic interchanges as spatial noise sources leads to downward bias of noise level up to 10 dBA.
Calculation of vehicle delay at signal-controlled intersections with adaptive traffic control algorithm
Authors: Andronov Roman , Leverents Evgeny
Published: June 2018

By widely introducing information technology tools in the field of traffic control, it is possible to increase the capacity of hubs and reduce vehicle delays. Adaptive traffic light control is one of such tools. Its effectiveness can be assessed through traffic flow simulation. The aim of this study is to create a simulation model of a signal-controlled intersection that can be used to assess the effectiveness of adaptive control in various traffic situations, including the presence or absence of pedestrian traffic through an intersection. The model is based on a numerical experiment conducted using the Monte Carlo method. As a result of the study, vehicle delays, queue length and duration of traffic light cycles are calculated subject to different intensities of incoming traffic flows, and the presence or absence of pedestrian traffic.
Integration of urban developers with regard to social and environmental responsibility
Authors: Nuzhina Irina , Zolotareva Maria , Vasileva Iuliia
Published: June 2018

The aim of this study is to develop a model for institutionalizing the social and environmental responsibility of the construction business as an important factor in the modern urban development. Methods of systems, logical and comparative analysis, as well as a questionnaire survey are used in the research. Based on the situation in Tomsk (Russia), public preferences and needs for construction products have been examined taking into account environmental friendliness and the quality of the urban environment. The results of the examination are presented in this paper. The study reveals the public need for building products and shows how these needs are related to greening the construction industry and developing the social and environmental responsibility of the construction business. The green urban development needs an environmentally sustainable regulation mechanism based on appropriate methods, tools and organizational forms of interactions between stakeholders in the construction industry. A concept for managing interactions between stakeholders in urban development is proposed on the basis of the ECOURBANBUILD platform. The integration based on this platform will create additional opportunities to implement the social and environmental responsibility of the construction business in the interests of sustainable urban development.
Expansion of urban recreation areas as a factor for human capital renovation
Authors: Ovsiannikova Tatiana , Nikolaenko Mariya , Chilbakova Mergesh
Published: June 2018

The paper is focused on the development of urban space on the basis of the modern urban development concepts. The role of urban environment in the development of individuals, their physical, intellectual and spiritual potential is described with the use of human capital theory. The City Recreation concept is suggested to be accounted while planning the urban territory development. The role of recreation areas in urban environment is described, classification of urban recreation areas is given. The paper recites the results of a social study devoted to evaluation of satisfaction of typical urban district residents with the number and quality of recreation areas. Recommendations are given on public spaces expansion to provide daily recreation.
Arthroscopic excision of intra-articular sub-periosteal osteoid osteoma of elbow: a case report
Authors: Goyal Tarun , Pandita Naveen , Paul Souvik
Published: June 2018

We are presenting a unique case of a sub-periosteal osteoid osteoma involving coronoid fossa in a 25-year-old male. He was symptomatic for 2 years and his presentation mimicked mono-articular inflammatory arthritis. His plain radiographs were normal and the computed tomogram confirmed features of a sub-periosteal osteoid osteoma. He was treated with arthroscopic excision of the lesion. Pain relief was noticed immediately after the surgery and maintained at latest follow up of 1 year.
Short-term complication rate following orthopedic surgery in a tertiary care center in Argentina
Authors: Willhuber Gaston Camino , Stagnaro Joaquin , Petracchi Matias , Donndorff Agustin , Monzon Daniel Godoy , Bonorino Juan Astoul , Zamboni Danilo Taype , Bilbao Facundo , Albergo Jose , Piuzzi Nicolas S. , Bongiovanni Santiago
Published: June 2018

Introduction: Registration of adverse events following orthopedic surgery has a critical role in patient safety and has received increasing attention. The purpose of this study was to determine the prevalence and severity of postoperative complications in the department of orthopedic unit in a tertiary hospital.

Methods: A retrospective review from the postoperative complication registry of a cohort of consecutive patients operated in the department of orthopedic surgery from May 2015 to June 2016 was performed. Short-term complications (3 months after surgery), age gender, types of surgery (elective, scheduled urgency, non-scheduled urgency, and emergency), operative time, surgical start time (morning, afternoon or evening), American Society of Anesthesiologists score and surgeon's experience were assessed. Complications were classified based on their severity according to Dindo-Clavien system: Grade I complications do not require alterations in the postoperative course or additional treatment; Grade II complications require pharmacological treatment; Grade III require surgical, endoscopic, or radiological interventions without (IIIa) or with (IIIb) general anesthesia; Grade IV are life-threatening with single (IVa) or multi-organ (IVb) dysfunction(s), and require ICU management; and Grade V result in death of the patient. Complications were further classified in minor (Dindo I, II, IIIa) and major (Dindo IIIb, IVa, IVb and V), according to clinical severity.

Results: 1960 surgeries were performed. The overall 90-day complication rate was 12.7% (249/1960). Twenty-three complications (9.2 %) were type I, 159 (63.8%) type II, 9 (3.6%) type IIIa, 42 (16.8%) type IIIb, 7 (2.8%) type IVa and 9 (3.6%) were grade V according to Dindo-Clavien classification (DCC). The most frequent complication was anemia that required blood transfusion (27%) followed by wound infection (15.6%) and urinary tract infection (6%).

Discussion: The overall complication rate after orthopedic surgery in our department was 12.7%. The implementation of the DCC following orthopedic surgery was an important tool to measure the standard of care.
Neutrophil Secretion During Blood Coagulation: Evidence for a Prekallikrein Independent Pathway
Authors: Plow Edward F , Plescia Janet
Published: June 2018

In association with blood coagulation, neutrophils undergo a secretory response (Plow, J Clin Invest 69: 564, 1982) and it has been suggested that plasma kallikrein is responsible for inducing this reaction (Wachtfogel et al., J Clin Invest 72: 1672, 1983). To assess the contribution of kallikrein to this response, the capacity of normal and prekallikrein-deficient blood and plasma to support secretion has been compared utilizing elastase as a marker of secretion. Serial dilutions of prekallikrein-deficient plasma were as effective as normal plasma in supporting neutrophil release of elastase. The extent of elastase release in spontaneously clotting normal and prekallikrein-deficient blood was similar. At 37° C in whole blood or at 22° C in plasma, prekallikrein activators had the same effect in neutrophil secretion in normal and prekallikrein-deficient blood and plasma samples. Taken together, these results provide evidence for the existence of a prekallikrein independent pathway that can function as a predominant mechanism for induction of neutrophil secretion during blood coagulation.
Evidence for a Discrete Binding Protein of Plasminogen Activator Inhibitor in Plasma
Authors: Wiman Björn , Lindahl Tomas , Almqvist Åsa
Published: June 2018

Gel-filtration experiments of mixtures of functionally active and inactive forms of plasminogen activator inhibitor (PAI) with human plasma or bovine serum albumin have provided evidence for the existence of a discrete binding protein of PAI in plasma. Most likely it is a glycoprotein with a molecular weight of approximately 150,000. The data suggest that it forms a very stable complex with functionally active forms of PAI, but not with the inactive or “latent” PAI. However, the PAI activity seems not to be significantly altered by the interaction with the binding protein. Assuming that a stoichiometric complex is formed, titration experiments suggest that a pool of normal human plasma contains about 40–50 mg of PAI-binding protein liter.
Renal and Hepatic Handling of Endogenous Tissue-Type Plasminogen Activator (t-PA) and Its Inhibitor in Man
Authors: Brommer E J P , Derkx F H M , Schalekamp M A D H , Dooijewaard G , Klaauw M M v d
Published: June 2018

In eight male patients with normal liver and kidney function fibrinolytic components were measured in arterial blood and in renal and hepatic vein blood, obtained during catheterization for analysis of hypertension. Blood samples were collected simultaneously from veins und corresponding arteries before and 5 minutes after the completion of intravenous injection of desmopressin (DDAVP), 0.4 μg/kg body weight over a 10 minute period.

DDAVP induced a rise in t-PA antigen and activity, and in von Willebrand factor, accompanied by a decrease in free PA-inhibitor level. We failed to detect a significant rise in plasma urokinase activity. The concentrations of fibrinogen, plasminogen, α2-antiplasmin, antithrombin III and coeruloplasmin did not change either.

Renal production of t-PA under basal conditions was inferred from a negative arterio-venous (A-V) difference in t-PA-activity and in t-PA-antigen levels but this could not be confirmed by orthogonal regression analysis of the same data. A-V differences of other fibrinolytic factors were negligible.

In the hepatic vessels a significant positive A-V difference of t-PA-activity and of t-PA-antigen levels was a uniform finding. After DDAVP, when plasma levels were elevated, the mean A-V difference was proportionally higher, consistent with a constant fractional elimination rate. Free PA-inhibitor was virtually absent from arterial blood after DDAVP, but appeared in hepatic vein blood, indicating either production of the inhibitor by the liver or dissociation of a circulating complex of t-PA and its inhibitor in the liver. The blood levels of the other investigated components did not show any change upon passage through the liver. Plotting of individual venous versus arterial levels of t-PA activity and of t-PA-antigen both before and after DDAVP injection yielded straight lines which in orthogonal regression analysis showed a slope significantly lower than unity; this was interpreted as net clearance of the activator. Clearance rate was not changed by DDAVP. Assuming a normal blood volume and hepatic blood flow in these subjects, the t½ of the disappearance of endogenous plasminogen activator over the liver can be calculated: t-PA-activity: 3.1 min, t-PA-antigen: 4.1 min. Since these figures are close to those found by others for the halfdisappearance time of t-PA from the entire circulation, it is concluded that t-PA is eliminated from the blood mainly by the liver. The t½ of disappearance of endogenous, free PA-inhibitor is about 3 times longer, in our example 10.4 minutes.
Slow Clearance of Acylated, Hybrid Thrombolytic Enzymes
Authors: Robinson Jeff H , Dodd Ian , Esmail Ashiq , Ferres Harry , Nunn Barbara
Published: June 2018

Two hybrid plasminogen activators, plasmin A-chair/t-PA Bchain and plasmin A-chain/u-PA B-chain have been synthestzed and purified in sufficient yield to permit measurement of clearance in small laboratory animals. Each hybrid enzyme was reversibly acylated at the active centre to allow the pharmacokinetic profile to be followed using an activity-based method without interference from plasma inhibitors. The acylated plasmin/u-PA hybrid had a clearance half-life (t½) in guinea pigs of approximately 80 min, whereas acyl u-PA had a t½ of 3 min. The pharmacokinetic profile of the acylated plasmin/t-PA hybrid was measured in guinea pigs, rats and rabbits; the half-lives in all three species were 60–80 min compared to half-lives of acylated, native t-PA that were in the range 0.5–1.0 min. Thus, plasmin A-chaincontaining, acylated hybrid enzymes are cleared some 30- to 100-fold more slowly than the acylated parent activators.
Mafenide (Sulfamylon™) Inhibits Plasmin Fibrinolytic Activity
Authors: Weisdorf Daniel J , Aldridge Jeffrey H
Published: June 2018

Inflammatory fibrinolysis by plasmin or phagocyte proteases is a major cause of skin graft failure on burn wounds where the primary adherent attachment of the skin grafts is due to the gluelike action of fibrin. We investigated the potential of mafenide acetate solution, an experimental topical antimicrobial used in treating grafted burn wounds, to modify plasmin fibrinolytic activity in vitro and, thus, its potential to alter or modify the integrity of the fibrin glue critical for skin graft viability. Immobilized 125I-fibrin monolayers were used to assay fibrinolytic activity from plasmin or from plasma activated by streptokinase or urokinase and modified by the presence of mafenide or ε-aminocaproic acid (EACA). While streptokinase-activated plasma lysed 52.7 ± 3.9% of the 125I-fibrin, this plasmin activity was more than 80% inhibitable by EACA. Mafenide acetate had no intrinsic fibrinolytic activity (1.5 ± 0.3%) nor activated plasma fibrinolytic potential (2.4 ± 0.5%), but produced significant and dose-related reduction in fibrinolytic activity (p <0.001). Other sulfonamide analogues lacking a para-methylamino reactive group had 10–100 fold less antifibrinolytic potency while lysine, like mafenide, able to compete for plasmin binding sites, could potently block fibrinolysis. Mafenide did not qualitatively alter activation of plasminogen or affect generation of complexes with α2 antiplasmin complexes. Adding mafenide only minutes following streptokinase-activated plasma or plasmin with the fibrin substrate reduced antifibrinolytic activity, supporting the conclusion that mafenide, like EACA, can modulate the interaction between fibrin and the plasmin reactive sites and thus prevent close plasmin/fibrin apposition. The union of mafenide’s potent antimicrobial activity with its antifibrinolytic potential is a fortuitous combination. The beneficial antifibrinolytic effect of mafenide may control inflammatory proteolysis, promote skin graft retention, and support wound healing.
Isolation, Identification and Pharmacokinetic Properties of Human Tissue-Type Plasminogen Activator Species: Possible Localisation of a Clearance Recognition Site
Authors: Dodd Ian , Nunn Barbara , Robinson Jeff H
Published: June 2018

Purified preparations of recombinant tissue-type plasminogen activator (t-PA) from the recombinant Bowes melanoma cell line TRBM6 were shown to contain multiple species of plasminogen activator. Using a combination of chromatography on Sephadex G25, Sephadex G75 and Heparin Sepharose CL6B we have isolated two fibrinolytically active species, which, under nonreduced SDS PAGE, have apparent Mr = 38,000 and 56,000. Double immunodiffusion studies indicated that both species were closely related to both the t-PA B chain and t-PA itself. N-terminal sequencing identified the Mr = 38,000 species as ala160-t-PA (essentially ΔFGKI t-PA) and the Mr = 56,000 species as ser1-tyr2-gln3-glyx-cys51 t-PA (ΔF t-PA), the latter probably produced by alternative splicing of the t-PA gene. The pharmacokinetic properties of N,N dirnethy1-4-aminobenzoyl (DAB) derivatives of these activators and native t-PA were determined in the guinea pig. Whereas DAB → ΔF t-PA showed a similar, rapid plasma disappearance profile to that of DAB → t-PA, DAB → ΔFGKI t-PA was cleared significantly slower. These results suggest that a rapid clearance recognition site resides on either the growth factor or kringle 1, or both, domains of t-PA.
Effects of Ellagic Acid upon the Rabbit Fibrinolytic System
Authors: Iatridis S. G , Iatridis P. G
Published: June 2018

The present investigation deals with in vivo studies of possible relations of active Hageman factor (HFa) to the problems of thrombolysis. The study is based upon animal experimentation in which 40 normal, 5 dicumarolized and 5 heparinized rabbits each received ellagic acid (Elac 10-2 M) by intravenous continuous infusion at a rate of 1 ml/min for a period of 25 min. The data suggest that the Elac infusion induced in vivo activation of HF. Streptokinase (SK) injection 25 min from the start of Elac i. v. infusion failed to induce clot lysis in blood drawn one min after its injection. The phenomenon was more prominent with low (SK 250 U or 500 U) concentrations of SK. With higher concentrations, SK-induced clot lysis activity was not affected by Elac infusion.

In dicumarolized and heparinized rabbits Elac infusion still counteracted the fibrinolysis activating effect of low concentration of SK. The possibility that the above described phenomenon was due to either hypercoagulability or to a non-specific inhibitory effect of Elac upon SK was explored and excluded.

It is concluded that HFa and SK have the same site of action. Thus it seems that HFa may block the precursor upon which SK acts by forming a complex with it. It is stressed that activation of this precursor by HFa requires a suitable surface.
Cold Promoted Activation of Factor VII
Authors: Gjønnæs H
Published: June 2018

The cold promoted shortening of the thrombotest-times occuring in the plasmas of the majority of women on oral contraception or in the last trimester of pregnancy when incubated overnight at 0°–4° was investigated.

The short thrombotest-times were caused by activation of factor VII in a time consuming reaction. Activation was also revealed in the intrinsic coagulation system, but the changes in the activities of coagulation factors other than factor VII were small.

Comparison was made between clot promoting effects of cooling and contact, and it was concluded that while contact apparently exerted its main effect in the intrinsic system, cooling predominately activated the extrinsic plasma coagulation system.

The cold promoted activation of factor VII seemed to be brought about by an activator.
Differing Procoagulant Activities in the Extracted Lipids of High and Low Density Platelet Plasma Membranes
Authors: Barber A. J , Triantaphyllopoulos D. C , Jamieson G. A
Published: June 2018

Platelet factor 3 activity has been examined in the high (d,1.120) and low (d,1.090) density platelet membranes obtained by the glycerol-lysis technique, and in the lipid fractions extracted from them. The following observations were made : procoagulant activity, as determined by the thromboplastin generation test, was equal in the two types of membrane and was higher than in the intracellular fractions ; the lipid fraction extracted from the low density membranes had a higher activity than that from the high density membranes; at high concentrations this extracted phospholipid had a mild anticoagulant effect. These results demonstrate functional differences between the two types of platelet membrane and favor a plasma membrane origin for platelet factor 3.
Experimental Model of Pulmonary Thrombosis in Rat
Authors: Tomikawa Munehiro , Ogawa Hidemasa , Abiko Yasushi
Published: June 2018

Experimental pulmonary thrombosis was induced in rats by intravenous infusion of 0.7 M lactic acid at a rate of 1.4 ml/100 g/hr for 2 hr. As acidosis progressed, a hyper-coagulable state developed and microthrombi were formed predominantly in the lung, but not conspicuously in other organs. Pulmonary thrombi thus formed were composed of aggregated platelets in the initial stage, and of fibrin in later stages. They progressively dissolved and had completely disappeared 12 hr after cessation of the lactic acid infusion.

During the infusion of lactic acid, the following changes were observed: progressive decreases in platelet count, fibrinogen, antiplasmin activity and fibrinolytic activity, and progressive increase in platelet adhesiveness. Plasma clotting time decreased to its shortest interval after one hour of the lactic acid infusion and remained at that level during the rest of the infusion. No fibrin degradation products (FDP) were detected.

After cessation of the lactic acid infusion, these parameters, except for fibrinolytic activity, tended to return to normal gradually while FDP increased markedly. Fibrinolytic activity measured by eugolobulin lysis time remained low, suggesting depletion of vascular activator. Plasminogen level began to fall gradually 6 hr after cessation of the lactic acid infusion.

These dynamic coagulo-fibrinolytic changes are discussed in relation to the morphological changes of thrombi.
The Relationship between Blood Coagulation and Thrombosis and Atherosclerosis in Man, Monkeys and Carnivores
Authors: Hawkey Christine M
Published: June 2018

A comparative survey of the blood coagulation mechanism has been carried out in man, non-human primates and carnivores. In man, the average rate of conversion of fibrinogen to fibrin by thrombin is slightly faster and the ability of plasma to neutralise thrombin is less than in the animal species. Otherwise, in general, the activity of the clotting mechanism in monkeys and carnivores is equal to or greater than that of man. These results do not explain the increased susceptibility to spontaneous cardiovascular disease seen in the human species.
Human Blood Platelets Accumulate Radioactivity from the Dipeptides 14C-glycylglycine and 14C-glycylproline
Authors: Boullin D. J , Heading Christine E
Published: June 2018

Human blood platelets were suspended in plasma or Krebs solution and incubated with radiolabeled glycylglycine or glycylproline in order to study cellular uptake. Platelets accumulated radioactivity against a concentration gradient. In the case of glycylglycine, uptake was not inhibited by cold, or metabolic inhibitors. Uptake of radioactivity derived from glycylglycine or glycylproline did not appear to involve saturable mechanisms since the platelet content of radioactivity was directly related to medium concentration even at high concentrations.

Chromatographic identification of radioactivity in cells and incubation media showed the glycylglycine was not extensively hydrolysed; 80 per cent of platelet radioactivity was intact dipeptide. With glycylproline, cellular radioactivity was entirely 14C-glycine. There was no direct evidence that this dipeptide actually entered the cells, and we could not determine whether entry did occur with subsequent hydrolysis, or whether hydrolysis preceded uptake.
Platelet Metabolism in Alcohol-related Thrombocytopenia
Authors: Cowan Dale H
Published: June 2018

The carbohydrate metabolism of platelets from patients with alcohol-related thrombocytopenia was studied. Rates of utilization and oxidation of 14C-glueose, 14C-lactate production, and pentose cycle activity were measured in resting platelets and in platelets stimulated with thrombin or epinephrine. The metabolism of resting platelets from patients with alcohol-related thrombocytopenia was normal but the metabolic responses to stimulation differed from normal : stimulation with thrombin was associated with subnormal 14C-lactate production and normal 14CO2 production and that with epinephrine was associated with normal 14C-lactate production and subnormal 14CO2 production. Addition of ethanol to normal platelets in vitro produced increases in 14C-glucose utilization and 14C-lactate production but not in 14C-glucose oxidation. Ethanol added to normal platelets in vitro did not affect the metabolic response to thrombin stimulation but produced a 50% reduction in the response to epinephrine. Platelet dysfunction in patients with alcohol-related thrombocytopenia is not due to quantitative abnormalities in platelet energy production. Ethanol appears, however, to alter the metabolic response to nucleotide release and degradation.
Abnormalities in Clotting and Thrombolysis as a Risk Factor for Stroke
Authors: Pilgeram L. O
Published: June 2018

Four hundred and six patients with ischemic thrombotic cerebrovascular disease (ITCVD) and 115 age-matched controls were studied to select risk factors which would identify ITCVD-prone individuals from a healthy population. The following factors were evaluated : soluble fibrin, plasminogen, plasminogen activator, fibrinogen, partial thromboplastin time, generation of thromboplastin, fibrin degradation products, triglycerides, type IV lipoproteinemia, and cholesterol. Discriminate function analyses were used to select those risk factors which best separate and classify the ITCVD and control subjects. The primary risk factors are the activated partial thromboplastin time, soluble fibrin, fibrinogen, and plasminogen activator. Utilizing only these four primary risk factors in a discriminate function, 93.2% of the patients were correctly classified. Consideration of other variables increased still further the dis-criminate function.
Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis
Authors: Wu Kenneth K , Hoak John C , Barnes Robert W , Frankel Stuart L
Published: June 2018

In order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.
The Effects of Amines on the Esterase Activities of Thrombin and Thrombokinase and on Several Clotting Tests
Authors: Roberts Phyllis S , Ottenbrite Raphael M , Fleming Patricia B , Wigand James
Published: June 2018

1. Choline chloride, 0.1 M (in 0.25 M Tris. HCl buffer, pH 7.4 or 8.0, 37°), doubles the rate of hydrolysis of TAME by bovine thrombokinase but has no effect on the hydrolysis of this ester by either human or bovine thrombin. Only when 1.0 M or more choline chloride is present is the hydrolysis of BAME by thrombokinase or thrombin weakly inhibited. Evidence is presented that shows that these effects are due to the quaternary amine group.

2. Tetramethyl ammonium bromide or chloride has about the same effects on the hydrolysis of esters by these enzymes as does choline chloride but tetra-ethyl, -n.propyl and -n.butyl ammonium bromides (0.1 M) are stronger accelerators of the thrombokinase-TAME reaction and they also accelerate, but to a lesser degree, the thrombin-TAME reaction. In addition, they inhibit the hydrolysis of BAME by both enzymes. Their effects on these reactions, however, do not follow any regular order. The tetraethyl compound is the strongest accelerator of the thrombokinase-TAME reaction but the tetra-ethyl and -butyl compounds are the strongest accelerators of the thrombin-TAME reaction. The ethyl and propyl compounds are the best (although weak) inhibitors of the thrombokinase-BAME and the propyl compound of the thrombin-BAME reactions.

3. Tetra-methyl, -ethyl, -n.propyl and -n.butyl ammonium bromides (0.01 M) inhibit the clotting of fibrinogen by thrombin (bovine and human proteins) at pH 7.4, imidazole or pH 6.1, phosphate buffers and they also inhibit, but to a lesser degree, a modified one-stage prothrombin test. In all cases the inhibition increases regularly as the size of the alkyl group increases from methyl to butyl. Only the ethyl com pound (0.025 M but not 0.01 M), however, significantly inhibits the polymerization of bovine fibrin monomers. It was concluded that inhibition of the fibrinogen-thrombin and the one-stage tests by the quaternary amines is not due to any effect of the com pounds on the polymerization process but probably due to inhibition of thrombin’s action on fibrinogen by the quaternary amines.
The Fractionation of Factor V from Human Plasma
Authors: Giddings John C.
Published: June 2018

Human plasma from normal donors and from patients with polycythaemia vera was fractionated in order to obtain a preparation of highly purified factor V. Fresh plasma was initially treated with aluminium hydroxide to remove factors II, VII, IX and X. Fibrinogen, factor VIII and most of the immunoglobulins were removed by precipitation with ethanol at -5° C. Crude factor V was precipitated with dilute acetic acid at pH 5.1, and then further purified by precipitation with acridine lactate (Rivanol), extraction with sodium chloride solution and column chromatography on agarose gel. Factor V was purified four hundred times with specific activity of 2.5-6.0 units per mg. protein. The final concentrate was devoid of activity of other coagulation factors but was heterogeneous on disc Polyacrylamide gel electrophoresis and Immunoelectrophoresis against anti human serum. On rechromatography on agarose gel there was a single peak of factor V activity, the molecular weight of which was estimated to be 300,000.
Specific Activities of Bovine Thrombin and Thrombin Components
Authors: Waugh D. F , Rosenberg R. D
Published: June 2018

Bovine thrombins (Gel-T) isolated from bioactivated crude prothrombin, obtained from Holstein, Jersey and Hereford single animal plasmas, occur in two distributions: either T1, T2 and T3 as 1:2:1 (Type I), or T1 and T2 as 1:1, with T3 absent or present to the extent of 5% of total Thrombin (Type II). Since components differentially denature during procedures used to fractionate, examinations of Gel-T were conducted so that statistical procedures could be used to evaluate particular variances. The variance due to the Gel-T preparative procedure and Gel-T intrinsic specific activity yield a coefficient of variance (Sc) of 0.55%. Thus 95% of single animal Gel-T specific activities fall within 1.1% of the average value. There are no significant differences between animals of different breed, or of bloods drawn from the same animal at different times. Evidently, Gel-T represent a reproducible reference standard. Analysis of distributions shows that the intrinsic specific activities of thrombin components are identical to within 1 %, and are approximately 1.0 NIH unit per 6.0 × 10−4 absorbance unit (3,250 ±450 NIH units per mg). The clotting time (τ) - thrombin concentration (T) relation, log τ = — ã log T + C, is examined. Over the range of τ from 15 to 60 sec it is shown that a T series can be reproduced to within 1 % in thrombin concentration. The variances in the assay system are then due almost entirely to variance in the assay substrate, fibrinogen. These are an Sc of 1.7% for τ̄ between sets of tubes containing dilute fibrinogen (τ-tubes) from one lot of Stock-F, and Sc of 12% between τ̄ for sets of τ-tubes from Stock-F prepared from different lots of Armour Fraction-I, and an Sc of 1.9% for ã̄( =0.679) for sets of T-tubes, obtained either from one Stock-F or Stock-F obtained from different lots of Fraction-I. Errors in several procedures for determining unknown thrombin concentrations are examined.
In Vitro and in Vivo Induction of Cryofibrinogen and “Paracoagulation” by Reptilase
Authors: Harder A.J , Straub P.W
Published: June 2018

Small doses of Reptilase, a snake venom enzyme which exclusively liberates fibrinopeptide A from fibrinogen, leads to formation of cryofibrinogen as well as ethanol- and protamine-precipitability of plasma both in vitro and in vivo. Precipitates obtained in vitro were shown to contain both fibrinogen and fibrin monomer. At 20° C Reptilase-treated fibrinogen solutions contained complexes with a sedimentation rate of 11-11.6 s20W, similar to those observed after thrombin. The artificial production of cryofibrinogenemia in volunteers is discussed in relation to spontaneously occurring cryofibrinogenemias in patients with intravascular coagulation.
Complement and Coagulation
Authors: Tomar R. H , Kolchins Diane
Published: June 2018

Serum β1c- β1a was found to be significantly depressed in 16 of 27 patients with disseminated intravascular coagulation. In vitro studies supported the finding that the serum β1c- β1a of urokinase-treated patients was not altered by fibrinolytic therapy. This strongly suggests that plasmin is not responsible for the low C3.
Prevention of the Liquoid-Induced Consumption Coagulopathy by the Protease Inhibitor Aprotinin
Authors: Müller-Berghaüs G , Maul F.-D , Lasch H.G
Published: June 2018

The protease inhibitor aprotinin reduced the incidence of the generalized Shwartzman reaction after Liquoid injection into the rabbit. This inhibitory effect is caused by the interference of aprotinin with the intravascular coagulation process (consumption coagulopathy) since decreases in fibrinogen levels after Liquoid injection were prevented. As the main anticoagulant effect of aprotinin is the inhibition of surface factor activation and as on the other hand Liquoid acts as a surface-active substance, it seems conceivable that aprotinin might prevent Liquoid-induced consumption coagulopathy by interfering with Hageman factor activation.

Aprotinin did not have any effect on the incidence of hemorrhages in the lungs in Liquoid-injected animals.

Furthermore, aprotinin prolonged the survival time of rabbits injected with Liquoid. This effect is not related to the action of aprotinin on the coagulation process.