bluuebunny/crossref_metadata_2025 huggingface dataset:
Economic planning approach for electric vehicle charging stations integrating traffic and power grid constraints
Authors: Huang Xiaoqing , Chen Jie , Yang Hang , Cao Yijia , Guan Weide , Huang Bicheng
Published: July 2018

Large‐scale electric vehicle (EV) charging will bring new challenges to coordination of grid and transportation. To facilitate large‐scale EV applications, optimal locating and sizing of charging stations have become essential. For the investors of a charging station, economic benefit is the primary and the only objective. In this context, this work studies the siting and sizing of EV stations based on the optimal economic benefit. Benefit changes with time, location and capacity. A planning model method considering net present value (NPV) and life cycle cost (LCC) is proposed to determine the site and the size of the charging stations. The model has integrated distribution network constraint, the user constraint and the traffic flow captured constraint. Origin–destination lines and voronoi diagram are selected to calculate the traffic flow and the service region of each charging station, respectively. The quantum genetic algorithm was adopted for a better convergence of the planning model. Finally, a coupled 33‐node distribution system and a 36‐node transportation system are used to simulate various scenarios in the coupled networks of grid and transportation. The simulation results show that by introducing a planning model method considering NPV and LCC, the charging station economical benefits can be further improved.
Photovoltaic–wind joint power probability model based on multiple temporal and spatial scale
Authors: Wu Feng , Jiang Zenan , Qian Junxia , Shi Linjun , Lin Keman
Published: July 2018

With an increasing number of renewable energy integrated into the power system, the impact of intermittent and random wind power and photovoltaic power on the power system is becoming larger and larger. To study the probabilistic correlation between wind power and photovoltaic power on different temporal and spatial scale, a joint probability model needs to be established. On the basis of the third‐order Gaussian mixture model, a photovoltaic–wind joint power probability model is proposed in this study. By analysing the statistical probability characteristics of the measured power output data, this method avoids the error accumulation caused by the individual modelling of the wind and photovoltaic generators and considers the joint correlation between wind power and photovoltaic power. On the basis of this model, the corresponding time series of wind power and photovoltaic power is calculated. The results indicated that the coastal joint power probability model and the inland joint power probability model are quite different on the same time scale, the parameters of joint probability model on different time scales are close to each other. The effectiveness of the proposed method is verified by the measured data.
Occlusion‐robust object tracking based on the confidence of online selected hierarchical features
Authors: Liu Mingjie , Jin Cheng‐Bin , Yang Bin , Cui Xuenan , Kim Hakil
Published: July 2018

In recent years, convolutional neural networks (CNNs) have been widely used for visual object tracking, especially in combination with correlation filters (CFs). However, the increasing complex CNN models introduce more useless information, which may decrease the tracking performance. This study proposes an online feature map selection method to remove noisy and irrelevant feature maps from different convolutional layers of CNN, which can reduce computation redundancy and improve tracking accuracy. Furthermore, a novel appearance model update strategy, which exploits the feedback from the peak value of response maps, is developed to avoid model corruption. Finally, an extensive evaluation of the proposed method was conducted over OTB‐2013 and OTB‐2015 datasets, and compared with different kinds of trackers, including deep learning‐based trackers and CF‐based trackers. The results demonstrate that the proposed method achieves a highly satisfactory performance.
GNSS/MEMS IMU ultra‐tightly integrated navigation system based on dual‐loop NCO control method and cascaded channel filters
Authors: Liu Baoyu , Zhan Xingqun , Liu Ming
Published: July 2018

A coherent scheme of federated architecture for the ultra‐tight integration of global navigation satellite system (GNSS) and MEMS (micro‐electro‐mechanical system) inertial measurement unit (IMU) is presented. Inside the receiver baseband, both the controls for code numerically controlled oscillator (NCO) and carrier NCO are designed. They are each composed of two parts, one part is derived from the navigation solutions of outer loop, and the other part is given on the basis of the channel pre‐filter outputs from inner loop. Each tacking channel has two filters of cascaded structure, one is the traditional pre‐filter which is used to achieve GNSS signal tracking errors, and the second one is an extractor which is constructed to extract navigation solution derivation errors from the designed NCO controls and the signal tracking errors. For the ultra‐tight integration navigation filter, the receiver clock residual error model after compensating the receiver clock drift is derived in detail. Finally, semi‐physical simulation environment of the proposed ultra‐tight integration scheme is built and closed‐loop experiment under high dynamics scenario is put forward. The simulation results show that the proposed integration scheme can stably and robustly track the GNSS signals, and can achieve accurate navigation solutions even in harsh cases.
High-resolution radio imaging of two luminous quasars beyond redshift 4.5
Authors: Frey S. , Titov O. , Melnikov A. E. , de Vicente P. , Shu F.
Published: July 2018

Context. Radio-loud active galactic nuclei in the early Universe are rare. The quasars J0906+6930 at redshift z = 5.47 and J2102+6015 at z = 4.57 stand out from the known sample with their compact emission on milliarcsecond (mas) angular scale with high (0.1 Jy level) flux densities measured at GHz radio frequencies. This makes them ideal targets for very long baseline interferometry (VLBI) observations.

Aims. By means of VLBI imaging we can reveal the inner radio structure of quasars and model their brightness distribution to better understand the geometry of the jet and the physics of the sources.

Methods. We present sensitive high-resolution VLBI images of J0906+6930 and J2102+6015 at two observing frequencies, 2.3 and 8.6 GHz. The data were taken in an astrometric observing programme involving a global five-element radio telescope array. We combined the data from five different epochs from 2017 February to August.

Results. For one of the highest redshift blazars known, J0906+6930, we present the first-ever VLBI image obtained at a frequency below 8 GHz. Based on our images at 2.3 and 8.6 GHz, we confirm that this source has a sharply bent helical inner jet structure within ∼3 mas from the core. The quasar J2102+6015 shows an elongated radio structure in the east–west direction within the innermost ∼2 mas that can be described with a symmetric three-component brightness distribution model at 8.6 GHz. Because of their non-pointlike mas-scale structure, these sources are not ideal as astrometric reference objects. Our results demonstrate that VLBI observing programmes conducted primarily with astrometric or geodetic goals can be utilized for astrophysical purposes as well.
Double plasma-resonance surfaces in flare loops and radio zebra emission
Authors: Karlický M. , Yasnov L.
Published: July 2018

Aims. The zebra structures observed in radio waves during solar flares are some of the most important structures used as diagnostics of solar flare plasmas. We here not only analyze the so-called double plasma-resonance (DPR) surfaces, but also estimate the effects of their form on the size of the zebra sources and brightness temperature.

Methods. To compute the DPR surfaces, we used numerical and analytical methods.

Results. We found that except for the case of a constant magnetic field across the loop, the DPR surfaces deviate from the constant plasma density surfaces. We found that the regime with a finite height scale has three forms of resonance surfaces depending on the magnetic field variation across the loop. This magnetic field variation also determines if in the generated zebra structure, an increase in gyro-harmonic number leads to an increase or decrease of the zebra stripe frequency. In the case with an infinite height scale, the resonance surfaces are parallel to the loop axis. Furthermore, we found that for highly polarized zebra structures that are generated at DPR surfaces close to the plasma frequency, the zebra emission is limited to the narrow escaping cone and the emitting source area increases with increasing viewing angle compared to the loop axis. Moreover, with increasing deviation of the DPR surfaces from those of constant density surfaces, the frequency bandwidth of the DPR emission increases and can cause the zebra stripes to overlap, which limits the zebra generation. For the zebra structures observed on 14 February 1999, 6 June 2000, and 1 August 2010 and the observed view perpendicular to the loop axis, we estimated that the brightness temperature is 3.67 × 1014K, 6.58 × 1013K, and 7.35 × 1015K, respectively. These brightness temperatures are much lower than those derived for the view along the loop axis (up to 1017K), and thus are more realistic. The area of the emitting source for coronal loops in the view perpendicular to the loop axis can be larger by several orders of magnitude than that in the view along the loop axis.
Ultrathin CdTe solar cells with absorber layer thinner than 0.2 microns
Authors: Wang Min , Li Xun , Wang Deliang
Published: July 2018

In this study, ultrathin Cadmium telluride (CdTe) solar cells with absorber thickness from 50 to 200 nm were fabricated. The short-circuit current (JSC) and open-circuit voltage (VOC) were found to decrease significantly with the thickness of absorber layer decreasing. The decrease of the JSC was mainly because of the insufficient light absorption. Even so, the JSC was still found to be 8.2 mA/cm2, which was about 32% of that of a normal CdTe solar cell when the thickness of absorber layer was reduced to ∼1% of that of a normal CdS/CdTe solar cell, i.e. 50 nm. The reasons, which caused the decrease of VOC, were also discussed in this study. The dark current–voltage characteristics were analyzed and the contribution of ohmic shunting current to the total leakage current was found to increase with the thickness of CdTe absorber layer decreasing. The device characteristics of the ultrathin CdTe solar cells under weak light irradiance and at different temperatures were also investigated. This study provides a guideline for the fabrication of ultrathin CdTe solar cells in the future.
Palpation des Thorax und der Lunge
Authors: Sengebusch Jürgen , Herzog Michael
Published: July 2018

Das Abtasten des Thorax führt man in der Regel durch, wenn der Verdacht einer Lungen- oder Pleurenerkrankung erhärtet werden soll.
Therapie der End-of-Dose-Fluktuationen: Notwendigkeit eines individualisierten Vorgehens
Authors: Lingor Paul , Claßen Joseph , Herbst Heinz , Storch Alexander , Urban Peter , Wellach Ingmar , Jost Wolfgang H.
Published: July 2018

Patienten mit einem idiopathischen Parkinsonsyndrom (IPS) weisen eine große Heterogenität an Symptomen und Komorbiditäten auf, die vor allem im fortgeschrittenen Stadium der Erkrankung eine individualisierte Therapiestrategie erfordern. Dies spiegelt sich auch in der Auswahl verschiedener Substanzklassen und Einzelwirkstoffe in der Therapie von End-of-Dose-Fluktuationen wider. Jede der verfügbaren Substanzen hat ein charakteristisches Wirkungs- und Nebenwirkungsprofil, welches bei der Anwendung berücksichtigt werden muss. Daher ist ein Austausch verschiedener Substanzen, auch unter medizin-ökonomischen Aspekten, nur bedingt möglich und erfordert sowohl die Berücksichtigung des therapeutischen Effektes als auch der Verträglichkeit beim einzelnen Patienten.
Klostermedizin – Heilwissen aus der Antike bis ins heutige Asien
Authors: Gottfried Mayer Johannes
Published: July 2018

Die Klostermedizin umfasst eine medizingeschichtliche Epoche, die auf die Regel des Heiligen Benedikt zurückgeht. Die Klöster entwickelten sich zum Ort medizinischer Versorgung. Mit Schriften der Antike als Vorbild, waren die Humoralpathologie und die vier Primärqualitäten die zentralen heilkundlichen Ansätze der Klostermedizin. Abhängig von den Primärqualitäten einer Erkrankung setzt man in der Klostermedizin Heilpflanzen mit jeweils gegenteiligen Qualitäten zur Behandlung ein.
Zusammenspiel zweier Volkskrankheiten
Authors: Schareck Birgit
Published: July 2018

Adipositas, Diabetes mellitus Typ 2 und die Nichtalkoholische Fettlebererkrankung (NAFLD) stehen in einem engen Zusammenhang. Mit zunehmender Prävalenz der Adipositas ist die NAFLD mittlerweile in Europa und den USA die häufigste Lebererkrankung. In Europa beträgt die Häufigkeit etwa 20–30 % 1. Rund 69 % der Erwachsenen mit Diabetes mellitus Typ 2 und 50 % der Erwachsene mit Dyslipidämien weisen eine NAFLD auf. Jeder Mensch mit einer Hypertriglyceridämie und einer Insulinresistenz hat auch eine NAFLD 2. Ihre Entstehung basiert auf multifaktoriellen Ursachen wie genetischen, epigenetischen, ethnischen, hormonellen und umweltbedingten Faktoren. Vor allem der westliche Lebensstil mit chronisch hyperkalorischer Ernährung und körperlicher Inaktivität prägen den Verlauf 3. Die periphere und hepatische Insulinresistenz ist das Bindeglied zwischen den Risikofaktoren 4.
Gutartige Parotistumore: moderne Therapiekonzepte
Authors: Grosheva Maria , Klußmann Jens Peter , Guntinas-Lichius Orlando
Published: July 2018

Bei gutartigen Parotistumoren ist es ein vorrangiges Behandlungsziel, die Morbidität des operativen Eingriffs zu senken. Standardisiertes intraoperatives
Vorgehen und Verfahren zur Minimierung des Operationsumfangs konnten das Risiko einer bleibenden Fazialisparese deutlich senken. Aktuelle evidenzbasierte
Therapieverfahren und mögliche Komplikationen nach Parotidektomie werden in diesem Beitrag näher erläutert.
Was wollen die jungen Chirurgen?
Authors: Roeth Anjali A. , Mille Markus
Published: July 2018

Um dem Mangel an chirurgischen Fachärzten entgegenzuwirken, muss man sich fragen, was der chirurgische Nachwuchs eigentlich will und wie man die Faszination des
Faches Allgemein- und Viszeralchirurgie unterstreichen kann. Die Chirurgische Arbeitsgemeinschaft Junge Chirurgen (CAJC) der Deutschen Gesellschaft für
Allgemein- und Viszeralchirurgie (DGAV) hat die Kernpunkte eines attraktiven chirurgischen Arbeitsplatzes gegliedert und zusammengefasst und bietet so
Lösungsansätze. Auf der einen Seite steht die strukturierte und transparente Weiterbildung, die ein festes Weiterbildungscurriculum, die Assistenz von
Teilschritten einer OP, regelmäßige Weiterbildungsgespräche, das Führen eines Logbuches, innerklinische Übungsmöglichkeiten sowie die Freistellung zu
Weiterbildungsmaßnahmen beinhalten sollte. Hand in Hand damit geht eine „lebenswerte Chirurgie“, die sich durch die Vereinbarkeit von Familie und Beruf, eine
bessere Planung des Klinikalltags, eine positive Feedback-Kultur, Work-Life-Balance, neue Arbeits(zeit)modelle sowie mehr Zeit für Lehre und Forschung
auszeichnet. Bei vielen dieser Punkte sollte der Chefarzt zentralen Vorbildcharakter übernehmen und dadurch den Grundstein für einen Strukturwandel innerhalb
der Klinik legen, besonders da viele Punkte leicht umzusetzen sind. So kann die Attraktivität der Faches Chirurgie schnell gesteigert werden und eine
„lebenswerte Chirurgie“ gelebt werden.
Preparation and Reactions of Trichloromethyl-Substituted Pyridine and Pyrimidine Derivatives
Authors: Zimmer Reinhold , Reissig Hans-Ulrich , Unger Lina , Accorsi Matteo , Eidamshaus Christian , Reich Dorian
Published: July 2018

The three-component reaction of lithiated methoxyallene, nitriles and trichloroacetic acid gave three model β-keto enamides that were starting materials for the synthesis of trichloromethyl-substituted pyridine and pyrimidine N-oxide derivatives. Upon treatment with acetic anhydride, the methyl group of the prepared pyrimidine N-oxides was converted into an acetoxymethyl group by a Boekelheide rearrangement. A few typical experiments also revealed that the trichloromethyl group of the prepared pyrimidine N-oxides can be replaced by an alkoxy or a hydroxy group, or transformed into an arylthiomethyl group. An alternative approach to β-keto enamides via the corresponding β-keto enamines was also examined and provided the expected 4-hydroxy-6-(trichloromethyl)pyridine derivative in good yield.
Visualization of von Willebrand Factor Multimers by Enzyme-Conjugated Secondary Antibodies
Authors: Brosstad F , Kjønniksen Inge , Rønning B , Stormorken H
Published: July 2018

A method for visualization of the multimeric forms of von Willebrand Factor (vWF) in plasma and platelets is described. The method is based upon: 1) Separation of the vWF multimers by SDS-agarose electrophoresis, 2) Subsequent blotting of the vWF multimers onto nitrocellulose, 3) Immunolocalization and visualization of the vWF pattern by the sequential incubation of the blot with a) primary vWF antiserum, b) peroxidase- or beta-galactosidase-conjugated secondary antibodies and a relevant chromogenic substrate.
Purification of Urokinase from Complex Mixtures Using Immobilized Monoclonal Antibody Against Urokinase Light Chain
Authors: Vetterlein David , Calton Gary J
Published: July 2018

The preparation of a monoclonal antibody (MAB) against high molecular weight (HMW) urokinase light chain (20,000 Mr) is described. This MAB was immobilized and the resulting immunosorbent was used to isolate urokinase starting with an impure commercial preparation, fresh urine, spent tissue culture media, or E. coli broth without preliminary dialysis or concentration steps. Monospecific antibodies appear to provide a rapid single step method of purifying urokinase, in high yield, from a variety of biological fluids.
Effect of Alpha-Tocopherol Administration on Platelet Function in Man
Authors: Steiner M
Published: July 2018

The effect of vitamin E administration on platelet function was evaluated in a group of normal, healthy volunteers. Platelet aggregation induced by collagen, ADP and epinephrine and platelet adhesion to collagen were measured at weekly intervals in 20 men and 27 women divided into 3 experimental groups of 12 individuals each and one control group of 5 men and 6 women. One experimental group was on a 6-week regimen of vitamin E in increasing dosages (4001.U.-1.2001.U.), the second group received aspirin, 300 mg every other day, and the third group was on a combination of vitamin E and aspirin. In the control group, platelet function was measured at weekly intervals. In women, vitamin E by itself produced a small but significant reduction of collagen-induced platelet aggregation. A similar trend was seen in men. However, the reduction never reached statistical significance. Adhesiveness to collagen was not affected by aspirin ingestion but showed a highly significant reduction in vitamin E and vitamin E + aspirin treated individuals. These results suggest that vitamin E administration could have a beneficial effect in patients suffering from arterial thromboembolic diseases.
The Clearance of Human Fibrinogen Fragments X and Y in Mice: A Process Mediated by the Fragment D Receptor
Authors: Pasqua John J , Pizzo Salvatore V
Published: July 2018

The clearance of radiolabeled human fibrinogen fragments X and Y was studied in the mouse model. Fragment X cleared rapidly from the circulation with less than 10% of the ligand remaining in the circulation at 4 hr. The clearance of fragment Y was somewhat slower, but was identical to the rate of clearance of fragment D,. Competition studies indicated that fragments X, Y, D, and D! dimer clear via the same, saturable pathway. Fragment E did not compete for the clearance of these ligands. Tissue distribution studies demonstrated that the liver was the principal site of clearance of all three ligands. The kidneys also cleared a fraction of each ligand in the order fragment D3>D2>D1 >Y>X. This pattern suggests that renal clearance is a passive phenomenon dependent on the size of the fibrinogen degradation product.
Influence of Platelet Activation on Erythrocyte Deformability
Authors: Palinski W , Torsellini A , Doni L
Published: July 2018

Erythrocyte deformability was demonstrated to be influenced by platelet activation. Deformability of erythrocytes suspended in autologous platelet poor plasma (PPP), obtained from platelet rich plasma (PRP), was significantly reduced when PRP had previously been incubated with a platelet activating substance (arachidonic acid, adrenaline or ADP). The possibility of a direct influence of the activating substance on erythrocyte deformability was examined and malondialdehyde formation was determined as an indicator of platelet activation. Erythrocyte deformability was not impaired when endoperoxide formation in platelets was blocked by an inhibitor of cyclooxigenase (acetylsalicylic acid). Plasma viscosity was not influenced by platelet activation as demonstrated by filtration and viscosimetry. Recent studies showed that prostacyclin (PGI2) increases erythrocyte deformability (1). The antagonistic action between prostacyclin released by vessel walls and products of platelet metabolism being well known, we discuss possible mechanisms of this effect and pathophysiological relevance of our results.
Purification of High Molecular Weight Urokinase from Human Urine and Comparative Study of Two Active Forms of Urokinase
Authors: Shibatani Takeji , Kakimoto Toshio , Chibata Ichiro
Published: July 2018

An improved method for the purification of high molecular weight urokinase to homogeneity from human urine was established. A yield of 32% with a 3,100-fold purification was obtained by Hyflo Super-Cel treatment, heat treatment at 60° C for 10 hr, serial column chromatography on DEAE-Sepharose CL-6B and 0-[3-(p-sulfophenylamino)-2-hydroxypropyl]-cellulose (SFOP-cellulose), and gel filtration on Ultrogel AcA 54. The low molecular weight form of urokinase was also purified to homogeneity by chromatography on hydroxyl apatite and gel filtration on Sephadex G-75 after the SFOP-cellulose column step. The high molecular weight urokinase had only one isoelectric form with a pi of 9.7, whereas the low molecular weight form had six isoelectric subforms with pi values between 9.4 and 6.4. The absorption coefficients at 280 nm of both urokinase forms were 13.61 and 13.50, respectively. Fibrinolytic and esterolytic activities of the two urokinase forms were compared in various assay methods.
Reduction of Gastric Haemorrhage by Fibrinolysis Inhibition – An Experimental Study in Rats
Authors: Stenberg Björn , Karlsson Lilian , Alpsten Magne , Risberg Bo
Published: July 2018

Gastric ulcerations were induced in rats by pyloric ligature and instillation of 1.0 N HCl. After four hours all rats had developed ulcerations. Increased release of plasminogen activators from the mucosa during these conditions has previously been demonstrated. In the present study we investigated the role of fibrinolysis inhibition versus Hz-receptor blockade on the gastric bleeding. Tranexamic acid – a synthetic inhibitor of the fibrinolytic system – was found to significantly (p <0.01) reduce blood loss into the gastric juice by 30% measured by 51Cr labelled red blood cells; cimetidine did not reduce the gastric haemorrhage under the experimental conditions used. Both treatment regimes significantly (p <0.02) reduced the secretion of gastric juice. These results indicate a contribution of the fibrinolytic system in gastric bleeding from experimentally induced gastric ulcerations.
Interaction of Heparin with Lipoproteins – Role of the Complex in the Inactivation of Thrombin and Plasmin
Authors: Kecskés E , Büki K G , Bauer P I , Machovich R , Horváth I
Published: July 2018

Heparin forms a complex with human low density lipoprotein (LDL) in the presence of Ca2+. The complex is dissociable by 0.5 M NaCI. Thrombin and plasmin causes the dissociation of the LDL-heparin complex, whereas factor Xa does not. Heparin, complexed with LDL, retains its enhancing effect on the rate of thrombin and plasmin inactivation by antithrombin III. LDL isolated from the plasma of persons with different pathological conditions did not alter the rate of thrombin inactivation by antithrombin III either in the absence or in the presence of heparin. Heparin seems to maintain its biological functions when it is in a complex with LDL.
The Effect of Serotonin Inhibition on Initial Microvessel Hemostasis and Platelet Aggregation In Vivo
Authors: Bergqvist D , Arvidsson S , Esquivel C O , Lindblad B , Haglund U
Published: July 2018

The role of serotonin (5-HT) in initial microvascular hemostasis is not fully understood. This study was made to evaluate the effect on hemostatic plug formation and laser-induced arteriolar microembolism of different substances which counteract the effect of 5-HT. Hemostatic plug formation time and stability was measured in the rabbit mesenteric microcirculation and laserinduced embolism in the rabbit ear chamber. Ketanserine, a selective 5-HT2-receptor blocker shortened arteriolar hemostatic plug formation time. Dihydroergotamine, an unselective blocker (with 5-HT- and α-adrenergic receptor affinity) increased venular hemostatic plug formation time and also decreased the hemostatic plug stability. Laser-induced platelet embolism was unaltered after both ketanserine and dihydroergotamine administration. The magnitude of these changes seems to exclude an important effect of 5-HT in initial microvessel hemostasis or on platelet activity.
Effects of Ticlopidine and Aspirin on Endotoxin-Induced Disseminated Intravascular Coagulation in Rats
Authors: Yoshikawa T , Murakami M , Furukawa Y , Takemura S , Kondo M
Published: July 2018

The effects of ticlopidine and aspirin on endotoxin-induced experimental disseminated intravascular coagulation (DIC) were studied in rats. Experimental DIC was induced by a 4 hr sustained infusion of endotoxin at a dose of 100 mg/kg. The rats were intraperitoneally injected with ticlopidine at 2.0, 20.0, 50.0, 100.0 or 200.0 mg/kg, or aspirin at 0.03, 0.3, 3.0 or 30.0 mg/kg, followed by the continuous infusion of 100 mg/kg/4 hr of endotoxin. A preventive effect against DIC was noted in all the parameters, such as fibrinogen and fibrin degradation products (FDP), fibrinogen level, prothrombin time, partial thromboplastin time (PTT), platelet count and the number of renal glomeruli with fibrin thrombi, in the rats treated with 20.0, 50.0, 100.0 or mg/kg of ticlopidine. Although a preventive effect was also noted in FDP, PTT, platelet count and the number of glomeruli with thrombi in rats treated with 0.03 or 0.3 mg/kg of aspirin, this agent was less effective than ticlopidine.
On the Interaction Between Human Plasma Kallikrein and C1-Esterase Inhibitor
Authors: Nilsson Torbjörn
Published: July 2018

The kinetics of the reaction between human plasma kallikrein and CĪ-esterase inhibitor was studied in a purified system. By monitoring the inhibition reaction for extended periods of time, it was found to proceed in two consecutive steps, a fast reversible second-order binding step followed by a slower, irreversible first-order transition. The rate constants in this reaction model were determined, as well as the dissociation constant of the initial, reversible enzyme-inhibitor complex. Thus, at 37° C the second-order rate constant was found to be 5 · 104 M -1 · s-1, the first order rate constant was 5 · 10-4 s-1 and the dissociation constant K was 1.5 · 10-8 M. Heparin (28 U/ml) and 6-aminohexanoic acid (10 mM) had no effect on the k1 of the of the reaction.
Kinetic Study of the Effect of Heparin on the Amidase Activity of Trypsin, Plasmin and Urokinase
Authors: Yomtova V M , Stambolieva N A , Blagoev B M
Published: July 2018

It was found that the effect of heparin on the amidase activity of urokinase (E C 3.4.21.31), plasmin (E C 3.4.21.7) and trypsin (E C 3.4.21.4) depended on the substrate used. No effect of heparin on the amidase activity of urokinase and trypsin was observed when Pyro Glu-Gly-Arg-p-nitroanilide (S-2444) and α-N-acetyl-L-lysine-p-nitroanilide (ALNA) were used as substrates. Heparin acted as a uncompetitive inhibitor of trypsin (Ki = 1.2×10-6 M), plasmin (Ki = 4.9×10-6 M) and urokinase (Ki = l.0×10-7 M) when Bz-Phe-Val-Arg-p-nitroanilide (S-2160), H-D-Val-Leu-Lys-p-nitroanilide (S-2251) and plasminogen, respectively, were used as substrates. These results, as well as the data obtained by studying the effect of the simultaneous presence of heparin and competitive inhibitors suggest that although heparin is not bound at the active center of these enzymes, it may influence the effectivity of catalysis.
The Action of Thrombin on Modified Fibrinogen
Authors: Osbahr A J
Published: July 2018

The modification of canine fibrinogen with citraconic anhydride modified the ε-amino groups of the fibrinogen and at the same time generated additional negative charges into the protein. The addition of thrombin to the modified fibrinogen did not induce polymerization; however, the fibrinopeptide was released at a faster rate than from the unmodified fibrinogen. The physical properties of the citraconylated fibrinogen were markedly altered by the modification of 50-60 lysine residues in one hour. A modified fibrinopeptide-A was released by thrombin from the modified fibrinogen and was electrophoretically more anionic than the unmodified fibrinopeptide-A. Edman analysis confirmed the modification of the lysine residue present in the peptide. The rate of removal of citraconylated fibrinopeptide-A from modified fibrinogen by thrombin was 30 to 40 percent greater than the cleavage of unmodified fibrinopeptide-A from unmodified fibrinogen. However, the modification of 60 or more lysine residues in the fibrinogen produced a decrease in the rate of cleavage of citraconylated fibrinopeptide-A. The results suggest that additional negative charge in the vicinity of the attachment of fibrinopeptide-A to canine fibrinogen aids in the removal of the peptide by thrombin.
Warfarin and Heparin Interaction with Prostacyclin-Like Activity Generated by Arterial Wall in the Rat
Authors: Doni M G , Piva E
Published: July 2018

A study was performed to evaluate the hypothesis that heparin opposes uncontrolled PGI2 production by vessels due to thrombin generation. We treated animals with warfarin, an inhibitor of liver synthesis of prothrombin and other vit. K-dependent clotting factors. In fact, if thrombin is presumed to be the stimulus for PGI2 production, warfarin should suppress this effect. As warfarin treatment did not affect significantly PGI2-like activity, we conclude that a different hypothesis is necessary to explain the phenomenon. On the other hand, i. p. sodium heparin effectively induced a decrease in PGI2-LA synthesis, whereas s. c. calcium heparin did not significantly influence it.
Plasma Levels of Platelet and Vascular Prostaglandin Derivatives in Children with Sickle Cell Anaemia
Authors: Buchanan George R , Holtkamp Christine A
Published: July 2018

Platelet and vascular endothelial prostaglandin derivatives were measured by radioimmunoassay in the plasma of 39 children with homozygous sickle cell anaemia and 27 control subjects. The levels of both thromboxane B2 and 6-keto-PGF1α, the stable endproducts of platelet and vascular prostaglandin metabolism, were significantly (p <0.001) greater in sickle cell anaemia plasma than in the plasma of the controls. There were no differences in levels of either 6-keto-PGF1α or thromboxane B2 between steady state and vaso-occlusive crisis in the sickle cell patients. Injury to the endothelial lining of blood vessels may occur in sickle cell anaemia as a consequence of contact with the abnormal erythrocytes.
Interaction of β2-Glycoprotein-I with Human Blood Platelets: Influence Upon the ADP-Induced Aggregation
Authors: Nimpf Johannes , Wurm Helmut , Kostner Gerhard M
Published: July 2018

The interaction of β2-glycoprotein-I (β2-G-I), a plasma constituent of unknown function, with blood platelets was studied. The following results were obtained: 1) β2-G-I binds to washed human platelets isolated by centrifugation (WP) at one kind of specific, saturable binding sites. The dissociation constant was found to be approx. 1 × 10−6M.

2) In the presence of physiological concentrations of Ca++ (2.5 mM), this specific binding is markedly reduced. Unspecific binding of β2-G-I to platelets, however, is not influenced by Ca++.

3) Platelets prepared by gel filtration (GFP), differing in their in vitro aggregability from WP, exhibit no specific binding of β2-G-I. Binding to GFP is also not induced by activation with thrombin, collagen or ADP.

4) β2-G-I causes significant alteration of the ADP-induced aggregation of GFP. Aggregation induced by thrombin, collagen, arachidonic acid or PAF-acether, however is not altered by β2G-I.

It is suggested, that pelleting during centrifugation causes irreversible rearrangements in the membrane of platelets.
Reduced Prostacyclin Survival After Fasting-Induced Elevation of Plasma Free Fatty Acids
Authors: Goodnight S H , Inkeles S B , Kovach N L , Connor W E
Published: July 2018

The anti-thrombotic effect of prostacyclin (PGI2) may be determined not only by its synthetic rate but also by its subsequent survival in blood. After its release from the vascular wall, prostacyclin binds to plasma albumin which stabilizes the molecule and prolongs its inhibitory effects on platelets. In vitro studies have shown that free fatty acids compete for the same albumin binding sites and may therefore displace PGI2 and substantially shorten its survival. To see if this competition could also occur in vivo, we produced a three-fold rise of plasma free fatty acid concentrations in ten normal volunteers by four days of fasting, which led to a significant reduction in prostacyclin survival as measured by a functional assay based on inhibition of ADP-induced platelet aggregation. The shortening of prostacyclin survival was associated with evidence of increased platelet reactivity as measured by the circulating platelet aggregate ratio test. Diseases that produce marked elevations of free fatty acids such as acute myocardial infarction may also lead to shortened PGI2 survival with potentiation of platelet mediated thrombosis.
Increased Yield of Human Tissue-Type Plasminogen Activator Obtained by Means of Recombinant DNA Technology
Authors: Browne M J , Dodd I , Carey J E , Chapman C G , Robinson J H
Published: July 2018

Extra copies of the human tissue-type plasminogen activator (t-PA) gene were introduced into the Bowes melanoma cell line. We obtained a recombinant cell line (TRBM6) which secretes approximately ten-fold more t-PA than the parent cell line. The identity of the plasminogen activator made by the new cell line was confirmed by sizing on sodium dodecyl sulphate polyacrylamide gels and by specific quenching using anti-t-PA antibody. We estimate that the recombinant line produces t-PA at a rate of approximately 3 pg/cell/24 hr and that t-PA accumulates in the harvest medium at a rate of approximately 4000 International t-PA Units/ml/24 hr.
Mouse Trophoblast Cells Are Constitutive Producers of Thromboplastin (Factor III) In Vitro
Authors: Dalaker K , Haug E , Prydz H
Published: July 2018

Trophoblasts from murine placenta synthesize thromboplastin in the absence of inducing agents and a functional complement system, nor is the rate or level of synthesis enhanced by inducers. A serum factor which is destroyed/removed by addition of oxalate and subsequent dialysis appears to enhance the ability of trophoblasts to synthesize thromboplastin.
Increased PA-Inhibitor Levels in the Postoperative Period – No Cause-Effect Relation with Increased Cortisol
Authors: Aillaud M F , Juhan-Vague I , Alessi M C , Marecal M , Vinson M F , Arnaud C , Vague P , Collen D
Published: July 2018

It has been reported that the level of PA-inhibitor increases in postoperative patients and on the other hand that glucocorticoids increase the PA-inhibitor level in cell culture. Because surgery is associated with increased plasma cortisol level, a relation between the postoperative increase in plasma cortisol and PA-inhibitor levels was looked for.

Blood samples were collected from 8 patients undergoing extensive abdominal surgery, before operation and postoperatively at 2 hr, 4 hr, 24 hr and daily for 7 days. Plasma cortisol and PA-inhibitor were increased 2 hr after surgery, when there was a significant correlation (p <0.05). The maximum increase was at 24 hr and the values fell to normal on day 6. An increase in t-PA related antigen (t-PA R:Ag) and a decrease in euglobulin fibrinolytic activity (EFA) also occurred.

In 7 controls 0.25 mg ACTH was given intravenously and blood was collected after ½, 1, 2, 4, 6 hr. Although the increase in plasma cortisol level following ACTH was comparable to that observed after surgery the increase was not associated with significant change in PA-inhibitor level, t-PA R: Ag or EFA.

A cause-effect relationship between the increased plasma cortisol and PA-inhibitor level could not be shown. The mechanism of the postoperative increase in PA-inhibitor thus remains unknown.
The Effects of Nicotine on PGI2 Production by Rat Aortic Endothelium
Authors: Bull H A , Pittilo R M , Blow D J , Blow C M , Rowles P M , Woolf N , Machin S J
Published: July 2018

The production of prostacyclin by rat aortic rings was measured following administration of nicotine by a single subcutaneous injection and after continuous subcutaneous infusion over 7 days. Single subcutaneous injections of nicotine at 1, 5, 10 or 20 mg/kg had no effect on prostacyclin production by rat aortic rings in comparison with controls. However, aortic rings obtained after 7 days continuous subcutaneous infusion of 0.54 g/ml of nicotine at the rate of 1 μl per hour produced significantly less prostacyclin than control animals.
A Comparative Study of the Effects of Adrenoceptor Antagonists on Platelet Aggregation and Thromboxane Generation
Authors: Greer I A , Walker J J , McLaren M , Calder A A , Forbes C D
Published: July 2018

Platelet aggregation and thromboxane A2 have been implicated in the pathogenesis of several forms of vascular disease. The aim of this study was to determine the effect of a wide range of adrenoceptor antagonists on platelet aggregation, and thromboxane A2 production, from normal human platelet rich plasma in vitro. Labetalol, pindolol and propranolol inhibited platelet aggregation to collagen in a dose dependent manner. Increasing the concentration of collagen “shifted” the dose response curve to the right. These 3 drugs also significantly inhibited thromboxane A2 generation in response to collagen but not to arachidonic acid. This effect was independent of any inhibitory effect of these drugs on platelet aggregation, and occurred at a drug concentration close to that obtained in vivo. Atenolol, metoprolol, prazosin and timolol were similarly assessed but had no effect on either platelet aggregation or thromboxane A2 generation. This ability of labetalol, pindolol, and propranolol to inhibit platelet aggregation and thromboxane generation, may be of clinical benefit in view of the increasing evidence implicating thromboxane A2 in the pathogenesis of vascular disease.
The Effects of Thromboxane Antagonism on the Transit Time of Platelets Through the Spleen
Authors: Peters A M , Lane I F , Sinclair M , Irwin J T C , McCollum C N
Published: July 2018

The spleen is well-known as a site for platelet pooling, although the mechanisms controlling intrasplenic platelet transit are essentially unknown. We tested the possibility that thromboxane A2 might be involved in this control by measuring intrasplenic platelet transit time in 10 subjects receiving a specific thromboxane A2 receptor antagonist (AH23848B; 70 mg; Glaxo Group Research Ltd), in 10 receiving aspirin (300 mg) plus dipyridamole (75 mg), and in 9 receiving placebo. All doses were administered 3 times daily commencing 4 days prior to transit time measurement.

Mean intrasplenic platelet transit time was measured by monitoring the kinetics of equilibration of 111In radiolabelled platelets between blood and spleen following intravenous injection. There was no difference between the mean transit time in the 3 groups of subjects, lending no support to the hypothesis that thromboxane A2 is involved in the control of platelet traffic through the spleen.
Endothelial Cells Degrade Extracellular Matrix Proteins Produced In Vitro
Authors: Laug Walter E , Weinblatt Mark E , Jones Peter A
Published: July 2018

Bovine aortic endothelial cells (BAEC) were grown on extracellular matrices produced by vascular smooth muscle cells or fetal bovine endothelial cells. The glycoprotein components of these complex substrates were degraded through activation of the serum zymogen plasminogen to plasmin, as well as by a plasmino- gen independent protease(s). The plasminogen independent enzyme might be a protease with elastolytic activity since the BAEC digested elastin present in smooth muscle cell derived matrices. The cells also displayed collagenolytic activity on both types of matrices.

The addition of the tumor promoter 12-0-tetradecanoyl-phorbol-13-acetate (TPA) (10−7 M) to the culture medium enhanced considerably the plasminogen activator and collagenolytic activities elaborated by BAEC resulting in an increased degradation rate of matrix glycoprotein and collagen components, whereas the elastolytic activity remained unaffected. Dex- amethasone (10−7 M), although suppressing plasminogen activator (PA) production by BAEC, did not alter their elastolytic activity allowing the cells to degrade the glycoprotein components of the matrices at an unchanged rate. The collagenolytic activity of the BAEC remained unaffected by dexamethasone.

These studies demonstrate that BAEC elaborate different proteolytic enzyme activities allowing them to degrade various components of extracellular matrices. These enzymatic activities may be modulated by certain agents thus changing the degradative capabilities of the BAEC.
On the Significance of Antithrombin-III, α2-Macroglobulin, α2-Antiplasmin, Histidine-Rich Glycoprotein, and Protein C in Patients with Acute Myocardial Infarction and Deep Vein Thrombosis
Authors: Gram Jørgen , Jespersen Jørgen
Published: July 2018

In a longitudinal study the plasma levels of antithrombin-III, α2-macroglobulin, α2-antiplasmin, histidine-rich glycoprotein, and protein C were followed in two groups of patients with acute myocardial infarction (AMI), one with and one without deep vein thrombosis (DVT). None of the sequentially studied periods revealed significant differences between the two groups of patients. However, small but consistently higher levels of histidine-rich glycoprotein in patients with DVT suggested the existence among patients submitted for myocardial infarction of a subgroup with increased thrombophilic potential. It was concluded that the inhibitors studied are of little value as possible indicators of the presence of DVT at early stages of the disease when clinical signs are absent and when antithrombotic prophylaxis should preferably be initiated.
Prevention of Arterial and Pulmonary Embolism by Oral Anticoagulants in Patients with Dilated Cardiomyopathy
Authors: Kyrle P A , Korninger C , Gössinger H , Glogar D , Lechner K , Niessner H , Pabinger I
Published: July 2018

The incidence of arterial embolism (AE) and pulmonary embolism (PE) during treatment with oral anticoagulants (OA) or without OA therapy was studied in 38 patients with dilated cardiomyopathy (DCMP). AE/PE occurred in 17 patients (44.7%) before initiation of OA treatment. The severity of DCMP was a risk factor for AE/PE, but not the presence of atrial fibrillation or intracardial thrombi. No AE/PE episodes occurred during the period of OA therapy. No major bleeding complications were seen, probably due to the moderate intensity of OA therapy (therapeutic range 5-15% Thrombotest® [TT], 2.1-4.8 International Normalized Ratio [INR], median TT value 11%, median INR 2.6). Recurrence of AE was observed in 4 of 5 patients in whom treatment with OA had been discontinued.
Equal Antiplatelet Effects of Aspirin 50 or 324 mg/Day in Patients After Acute Myocardial Infarction
Authors: De Caterina R , Giannessi D , Boem A , Bernini W , Battaglia D , Michelassi C , Dell’Amico F , L’Abbate A , Patrignani P , Patrono C
Published: July 2018

This study explores the effects on some hematological parameters of a low-dose aspirin regimen (50 mg/day) versus a conventional aspirin treatment with reported antithrombotic efficacy (324 mg/day), in patients with acute myocardial infarction. Fifteen patients were randomized into 3 equal groups receiving 50 mg or 324 mg aspirin or placebo, daily for 21 days. Compared with placebo, bleeding time was significantly and similarly prolonged with both aspirin doses (+ 71 ± 22% and + 69 ± 20%, mean ± S.D.). Aspirin 50 mg/day suppressed arachidonate-induced platelet aggregation and secondary phase aggregation after ADP and adrenaline. Collagen aggregation was inhibited by 44 ± 15%. In no case were differences in the antiplatelet effects of the two doses observed. The effects of 50 mg/day persisted without attenuation during the observation period. Platelet thromboxane B2 generation during arachidonate-induced aggregation was inhibited by 95 ± 2 and 99 ± 1% compared to placebo group after 50 and 324 mg/day, respectively (P between doses <0.05). No change was observed with any treatment in coagulation time, prothrombin time or plasma thromboplastin time. Thus, in patients with acute myocardial infarction, the antiplatelet effects of aspirin 50 mg/day are stable over time and superimposable on those of 324 mg/day. The antithrombotic efficacy of aspirin 50 mg/day remains to be tested clinically.
Quantitative Assessment of Soluble Fibrin in Plasma by Affinity Chromatography – A Comparative Study with desAA-Fibrin, desAABB-Fibrin and Fibrinogen
Authors: Thiel Wilfried , Delvos Ulrich , Müller-Berghaus Gert
Published: July 2018

A quantitative determination of soluble fibrin in plasma was carried out by affinity chromatography. For this purpose, desAA-fibrin and fibrinogen immobilized on Sepharose 4B were used at the stationary side whereas batroxobin-induced 125I-desAA-fibrin or thrombin-induced 125I-desAABB-fibrin mixed with plasma containing 131I-fibrinogen represented the fluid phase. The binding characteristics of these mixtures to the immobilized proteins were compared at 20° C and 37° C. Complete binding of both types of fibrin to the immobilized desAA-fibrin was always seen at 20° C as well as at 37° C. However, binding of soluble fibrin was accompanied by substantial binding of fibrinogen that was more pronounced at 20° C. Striking differences depending on the temperature at which the affinity chromatography was carried out, were documented for the fibrinogen-fibrin interaction. At 20° C more than 90% of the applied desAA-fibrin was bound to the immobilized fibrinogen whereas at 37° C only a mean of 17% were retained at the fibrinogen-Sepharose column. An opposite finding with regard to the tested temperature was made with the desAABB-fibrin. Nearly complete binding to insolubilized fibrinogen was found at 37° C (95%) but only 58% of the desAABB-fibrin were bound at 20° C. The binding patterns did not change when the experiments were performed in the presence of calcium ions. The opposite behaviour of the two types of soluble fibrin to immobilized fibrinogen at the different temperatures, together with the substantial binding of fibrinogen in the presence of soluble fibrin to insolubilized fibrin in every setting tested, devaluates affinity chromatography as a tool in the quantitative assessment of soluble fibrin in patients’ plasma.