bluuebunny/crossref_metadata_2025 huggingface dataset:
VIIIR: Ag in Platelets from Patients with Various Forms of von Willebrand’s Disease
Authors: Holmbeg L , Nilsson Inga Marie
Published: August 2018

Thirty patients with various forms of von Willebrand’s disease were investigated for VIIIR: Ag in their platelets. VIIIR: Ag was extracted from washed platelets and measured both with electroimmunoassay and a sensitive immunoradiometric assay. Six patients had severe von Willebrand’s disease, type I, with very low or no VIIIR: Ag in their plasma. None of these patients had any VIIIR: Ag detectable in their platelets. All 19 patients with mild von Willebrand’s disease had VIIIR: Ag in their platelets but the values often fell below those of normal controls. Five patients with genetic variants of von Willebrand’s disease also had values in their platelets corresponding to those in plasma.

Von Willebrand’s disease is a bleeding disorder caused by an inherited defect in so-called factor VIII related antigen (VIIIR: Ag), which is a protein normally occurring in plasma (Zimmerman et al. 1971), endothelial cells (Bloom et al. 1973), platelets (Howard et al. 1974) and megakaryocytes (Piovella et al. 1974). The defect leads to a prolonged bleeding time and as a rule a secondary decrease in factor VIII clotting activity (VIII: C) in plasma. Von Willebrand’s disease is a heterogeneous condition (Holmberg and Nilsson 1972). It varies widely in severity, and a genetic variation causing a qualitative abnormality of VIIIR :Ag is also known (Peake et al. 1974). The disease is, as a rule, transmitted as an autosomal and dominant trait, but some severely affected individuals have been suspected to be homozygous for an autosomal and more or less recessive gene (Italian Working Group 1977, Shoa’i et al. 1977).

The clinical severity of the disease varies with the amount of functional VIIIR :Ag (VIIIR: RCF) in plasma (Holmberg and Nilsson 1972, Meyer et al. 1974). Patients with severe von Willebrand’s disease have very little or no VIIIR: Ag in their plasma. They also lack the protein in their endothelial cells (Holmberg et al. 1974 b). There is evidence that also their platelets are devoid of VIIIR :Ag. In the present investigation we studied the platelet content of VIIIR: Ag in a series of patients with various types of von Willebrand’s disease. Both electroimmunoassay (EIA) and a more sensitive immunoradiometric assay (IRMA) for VIIIR: Ag were used.
The Optimal Therapeutic Range in Oral Anticoagulation
History and Proposal
Authors: Loeliger E A
Published: August 2018

For patients on oral anticoagulation controlled with Quick’s prothrombin time test using rabbit brain thromboplastin American clinicians proposed in the early 1940s that the lower limit of prolongation be taken at 1.5 and the upper limit at 3, corresponding to 10-30 per cent prothrombin activity on a saline dilution curve. Thromboplastins derived from other tissues and species were later introduced, methods were modified, and adsorbed plasma was used instead of saline in the construction of the dilution curve to obtain percentage prothrombin activity; ratios and percentages lost their initial significance, but too often without the clinicians� awareness. With the detection of PIVKAs, finally, it became clear that transformation of prothrombin times into percentage activity, as obtained from dilution curves, could never be a valid means of standardization. It also became evident that only direct comparison of thromboplastins with (fresh) plasma from patients on stabilized oral anticoagulants could be used to determine equivalent therapeutic ranges for different types of thromboplastins. Reference thromboplastins were established and calibration procedures developed. A series of well-controlled clinical trials has provided sufficient information to define, in terms of these reference thromboplastins, therapeutic ranges for the prophylaxis and treatment of venous as well as arterial thrombosis. Definition of the ranges in terms of the biochemical defect induced by coumarin congeners remains, however, to be established.
Anticoagulant Kinetics Following Bolus Injection of Heparin
Authors: Mockros Lyle F , Hirsch Samuel D , Zuckerman Leon , Caprini Joseph A , Robinson William P , Vagher J Paul
Published: August 2018

Bolus injections of beef-lung heparin at doses of 50, 100 and 200 u/kg body weight were administered to mongrel dogs. Neutralization of the anticoagulant effect was evaluated using sequential samples withdrawn from the animals (in vivo samples) and aliquots from a 100 ml sample withdrawn from the dog at 30 minutes post-injection (in vitro samples). Tests of the activated partial thromboplastin time (APTT) and prothrombin time (PT) did not indicate the degree of anticoagulation. Tests of the whole blood clotting time (WBCT), celite- activated whole blood clotting time (ACT), and celite-activated thromboelastography (ATEG) indicated pronounced hypocoagulability immediately after the injection, followed by a fairly rapid decay in anticoagulability, and a slight Ziype/coagulability at three to four hours post injection. The results from the in vitro ATEG samples were essentially identical to those on the in vivo samples, whereas the in vitro WBCT and ACT generally indicated higher degrees of anticoagulation. Calculated half-lives of the anticoagulant effect are significantly shorter than previously reported, being 18 to 36 minutes, and slightly dose dependent. The decay of the effects, however, does not appear to follow a single exponential curve, dropping very rapidly immediately post-injection and at a somewhat slower rate 60 or more minutes post-injection.
Relationship Between Kallikrein Release and Factor XII in Normal Persons and Carriers of the Hageman Trait
Authors: Torres M , Ercoreca L , Lucia J F , Giralt M , Raichs A
Published: August 2018

In four healthy subjects with Factor XII levels equal to or below 50% (selected at random from 100 persons) the release of Kallikrein was studied in order to establish the relationship between the above data and those found in four Hageman trait carriers showing levels of Factor XII above the lowest normal limits. It was found that for similar amounts of Hageman activity three of the carriers showed significantly less release of Kallikrein than the control subjects in whom it was normal.

The conclusion was reached that the additional determination of the amount of Kallikrein released may be of value in the detection of carriers of the Hageman trait.
In Vitro Stability of Human Fibrinopeptide B
Authors: Qureshi G D , Vennart William C
Published: August 2018

In anticipation of a future clinical application of plasma fibrinopeptide B (FPB) measurement, we studied the stability of FPB in an ultrafiltrate of normal plasma, normal urine and alkaline buffer by measuring the immunoreactivity of the peptide by FPB radioimmunoassay using anti FPB serum (R-29). FPB was unstable in an ultrafiltrate of plasma and urine and demonstrated a temperature dependent loss of activity. In plasma ultrafiltrate the loss of immunoreactivity was not significant during the first 24 hours, however, 92% of the peptide activity was lost at the end of seven days at 25° C and 37° C. The rate of FPB degradation in urine was comparable. The peptide was stable in an alkaline buffer (pH 8.5) at temperatures ranging from �10° C to 37° C or in plasma ultrafiltrate or urine when incubated at �10° C. Treatment with carboxypeptidase B or leucine aminopep- tidase for two hours at 37° C (enzyme/substrate molar ratio of up to 1:100) did not cause a loss of FPB immunoreactivity. EDTA (1.0 mM) and Trasylol (500 units/ml) completely stabilized the peptide in a plasma ultrafiltrate.
In Vitro Thrombogenicity Tests of Factor IX Concentrates. II: Effects of Phospholipids and Heparin
Authors: Prowse C V , Boffa M C , Guthrie C , Pepper D S
Published: August 2018

Measurement of the total phospholipid (and that portion active in coagulation) in factor IX concentrates revealed no correlation with in vitro tests of potential thrombogenicity, except in the case of the recalcification time and the thrombin generation test which may detect coagulant phospholipid as well as the presence of thrombogenic enzymes. This is probably due to separation of the prothrombin complex proteins from most phospholipid during ion-exchange chromatography. Although low levels of phospholipid remain in the final product these are apparently insufficient to effect appreciable activation of factor IX concentrates despite low levels of antithrombin III.

Two tests which measure the formation of thrombin and factor Xa after recalcification of concentrates were affected by the addition of exogenous phospholipid. However this is a relative effect such that differences are quantitative rather than qualitative.

Heparin addition during production of factor IX concentrate was found to have only minor effects on the results of in vitro thrombogenicity tests of the final product. This was confirmed in the laboratory by incubation of unheparinised products with heparin for periods of up to 6 hr.
Fibrinogen-Induced Polymerization Via the Process of Methylation
Authors: Osbahr A J
Published: August 2018

Fibrinogen is polymerized by a number of group specific reagents including diazomethane, thionyl chloride and di-methyl sulfate at pH 7.4. The relationship between the number of methyl groups incorporated into fibrinogen and the extent of polymerization was evaluated. With diazomethane and thionyl chloride as modifying agents, polymerization ensued in approximately IV2 hr with extensive modification of fibrinogen. On the other hand, m�thylation via di-methyl sulfate-induced polymer formation occurs in approximately 35 min with primarily carboxylic acid group esterification. The polymerized fibrinogen formed under these conditions exhibited properties that were closely similar with the physiological fibrin clot.

Amino group determinations revealed the m�thylation of amino acid residues other than the expected esterification of carboxylic acid groups. Diazomethane induced both N- methylation of lysine, as well as O-methylation of tyrosine, as estimated from spectrophotometric analysis. On the other hand, thionyl chloride modified only a small number of amino groups, and di-methyl sulfate modification resulted in no significant amounts of amino group methylation during the process of modification induced polymerization of fibrinogen.

The profile of the number of methoxyl groups incorporated into fibrinogen with time for diazomethane modification may reflect a conformational change in the protein due to a more nonspecific m�thylation. Both the reagent and the conditions of modification were found to be important in achieving a selective modification of fibrinogen.

A possible interpretation of these results is the esterification of carboxylic acid groups in the fibrinogen with reduction in the prevailing carboxylate ion negative repulsion, thereby achieving an increased protein-protein interaction with a resulting polymerization.
Isolation of Peptides with Anti-Urokinase Activity from the Human Placenta
Authors: Uszynski Mieczyslaw
Published: August 2018

It is known that the fibrinolysis inhibitors in the human placenta are proteins which, in vitro, block urokinase plasminogen activation and are for this reason called urokinase inhibitors. In the present study it was found, for the first time, that a low-molecular urokinase inhibitor also occurs in the human placenta. It is a peptide which can be isolated through a three-step procedure: dialysis of human placenta homogenate, extraction of peptides from a filtrable fraction, and ion exchange chromatography of peptides on a Dowex-50 column.
Differential Effects of Cytochalasin B on Platelet Release, Aggregation and Contractility: Evidence against a Contractile Mechanism for the Release of Platelet Granular Contents
Authors: Kirkpatrick John P , McIntire Larry V , Moake Joel L , Cimo Philip L
Published: August 2018

Cytochalasin B alters the structure and functional properties of filamentous actin. Platelet-mediated clot retraction in dilute platelet-rich plasma (PRP) is inhibited progressively at cytochalasin B concentrations of 0.01 mg/ml, 0.05 mg/ml and 0.1 mg/ml. Dynamic rheological measurements of recalcified PRP in a Weissenberg Rheogoniometer indicate that platelet contractility (as reflected in measurements of elastic moduli) is reduced by 33%, 57% and 63% at cytochalasin B concentrations of 0.01, 0.05 and 0.1 mg/ml, respectively.

In contrast, pre-incubation of human platelet-rich plasma (PRP) with 0.01 mg/ml or 0.05 mg/ml cytochalasin B does not inhibit collagen-induced [14C-]serotonin release or collagen-induced-platelet aggregation, which is dependent on the release of ADP from platelet dense granules. Even at a cytochalasin B concentration of 0.1 mg/ml, collagen-induced [14C-]serotonin release and aggregation are impaired only moderately. Cytochalasin B does not interfere with the uptake by platelets of [14C-]-serotonin, or with the kinetics and extent of clot formation in platelet-free plasma.

Thus, concentrations of cytochalasin B which impair platelet contractility do not inhibit the release of platelet dense granule contents. It is concluded that neither the platelet release reaction nor platelet aggregation is dependent on platelet contractile mechanisms.
Increased Plasma Fibrinogen and Platelet-Aggregates in Type II Hyperlipoproteinaemia
Authors: Lowe G D O , Drummond Maureen M , Third Jane L H C , Bremner W F , Forbes C D , Prentice C R M , Lawrie T D V
Published: August 2018

Plasma fibrinogen and platelet-aggregates (method of Wu and Hoak) were measured in 21 patients with familial Type II hyperlipoproteinaemia and 21 matched control subjects. Patients with hyperlipoproteinaemia had increased levels of fibrinogen and platelet- aggregates (p<0.01). Young patients with hyperlipoproteinaemia had prematurely high fibrinogen levels, and the normal rise in fibrinogen during adult life was abolished. There were no statistically significant correlations within the patient group between fibrinogen, platelet-aggregates, and plasma lipids. High fibrinogen and platelet-aggregate levels may play a part in the development of the premature arterial disease associated with Type II hyperlipoproteinaemia, or may be markers of arterial injury.
A Retrospective Survey of Injuries Occurring in Dogs and Handlers Participating in Canicross
Authors: Whyle Caitlin , Lafuente Pilar
Published: August 2018

Objectives Canicross is a popular canine and human cross-country sport. The purpose of this study was to identify the most common injuries, their severity, risk factors and the recovery.

Methods An internet-based retrospective survey design was used to examine the characteristics of injuries, demographic and competition information and associations with injury rate.

Results A total of 160 surveys were received and indicated that at the time of the survey 21.9% of dogs (35/160) had experienced at least one injury. Lacerations, abrasions and punctures were the most common injury type (22/49), most frequently occurring in the footpads of the forelimb (13/16). The majority of dogs (38/49) recovered from their injuries. Sixty-nine out of 147 of the human handlers experienced injuries while competing; ankle injuries (25/69) and bruises, cuts and grazes (20/69) were the most common injuries. Risk factors for injuries were being a purebred Labrador, dogs running with another dog and additionally competing in agility.

Conclusions Labradors, dogs running with another dog and dogs also participating in agility competitions were at higher risk for injury. Injuries of the footpads of the forelimb were the most common injuries in dogs. Most dogs had a complete recovery from their injuries.

Clinical Significance This is the first study that gives us insight into injuries occurring in dogs and handlers competing in canicross. This will help making recommendations for this sport as well as enable veterinarians to understand the risks and injuries.
Assay of Fletcher Factor (Plasma Prekallikrein) Using an Artificial Clotting Reagent and a Modified Chromogenic Assay
Authors: Soulier Jean-Pierre , Gozin Danielle
Published: August 2018

An artificial clotting reagent lacking in Fletcher factor (plasma prekallikrein, PPK) was made by mixing human plasma, activated by 5 mg/ml of celite, then kept 16 hours at 37° to destroy most of the plasma kallikrein, plus rabbit plasma (which is devoid of XII and Fletcher activity).

Chromogenic assay using a tripeptide substrate was also modified to exclude the interference of the endogenous contact factors. Celite eluate was used instead of kaolin or dextran sulphate for the activation.

Using both these methods, it is possible to distinguish between Fletcher trait (PPK deficiency) and other contact factors such as factor XII and HMWK deficiencies, which do not activate with kaolin or dextran sulphate. These simple clotting and enzymatic assays give specific and well correlated results for PPK estimation.
Intravascular Coagulation in Autopsy Cases with Liver Diseases
Authors: Oka Kazunari , Tanaka Kenzo
Published: August 2018

184 autopsy cases with liver diseases were examined clinicopathologically with special reference to the incidence and distribution of microthrombi and classic thrombi in various organs.

Microthrombi and/or classic thrombi were found in one or more organs in 50.0% to 59.4% of the patients with various liver diseases. But only 4 among 184 patients had many microthrombi in more than three organs and the incidence of disseminated intravascular coagulation seemed to be low in autopsy cases with liver diseases. Incidence of microthrombi showed no significant difference in the groups with and without portal vein thrombosis.

Hemorrhage in the upper alimentary tracts of the patients with liver cirrhosis did not seem to develop by disseminated intravascular coagulation. Consumption of clotting factors in liver diseases seemed to occur by thrombus formation in portal vein and esophageal varices and by hemorrhage in various organs.
Effect of Diuresis on Urokinase Excretion Rate
Authors: Matsuo Osamu , Kawaguchi Tomoko , Kosugi Tadayoshi , Mihara Hisashi , Kimura Takahiko
Published: August 2018

UK excretion rate in the diuretic state was investigated in human and animal studies. Loading of water, beer or diuretics in man decreased the UK excretion rate as urine flow increased. A linear relation between UK excretion rate and urine specific gravity was observed. Simultaneous loading of water and exercise suppressed the decrease in UK excretion rate and the increase in urine flow. In animal studies, a null value for UK excretion rate was observed as a result of giving physiological saline and/or furosemide, and a remarkable increase in urine flow was induced. These results clearly suggest the existence of a relation between renal function and UK excretion rate.
SEM Observations on the Mechanism of Platelet Release from Megakaryocytes
Authors: Djaldetti Meir , Fishman Pnina , Bessler Hanna , Notti Ida
Published: August 2018

Normal human bone marrow megakaryocytes were examined with the scanning electron microscope (SEM) to clarify the mechanism of platelet release. Several types of megakaryocytes were detected according to their surface appearance, i. e. with wrinkles, ridges, villous formations, round blebs and cells with platelets still attached to the cell membrane. These observations are consistent with the concept that bleb formation is at least one of the mechanisms for platelet liberation.
Inhibition of Spontaneous Platelet Aggregation by Sulfinpyrazone
Authors: Nenci G G , Agnelli G , Berrettini M , Parise P , Ballatori E
Published: August 2018

In a randomized double-blind crossover study in 16 patients with enhanced in vitro spontaneous platelet aggregation, sulfinpyrazone proved to be effective in normalizing platelet aggregability within 4 days after initiation of therapy.
Platelet Malonyldialdehyde Formation: An Indicator of Platelet Hyperfunction
Authors: Stuart Marie J
Published: August 2018

In 25 normal controls (Group I) and in 23 patients (Groups II and III) platelet malonyldialdehyde formation in the presence of N-ethyl maleimide (NEM) or thrombin was evaluated as an indicator of enhanced platelet function. 12 patients (Group III) with diabetes mellitus, nephrotic syndrome, or acute lymphatic leukemia in remission either exhibited spontaneous platelet aggregation (6/12), or enhanced platelet aggregation to minimal concentrations of ADP and Epinephrine (6/12). In these same Group III patients platelet malonyldialdehyde formation was markedly increased (p <0.0005) when compared to the values in the Group I normal controls. Studies in the 12 abnormal subjects later revealed normal aggregation patterns in 6/12 on follow-up evaluation. Concomitant estimation of platelet malonyldialdehyde at this time revealed a decrease into the normal range for platelet malonyldialdehyde values in the presence of thrombin in these 6 patients. Although significantly decreased from initial levels, (p <0.0005) malonyldialdehyde estimation in the presence of NEM was still slightly above the normal range. In 11 patients (Group II) both platelet aggregation tracings and malonyldialdehyde formation was normal and similar to values in the control population. Platelet malonyldialdehyde is a byproduct of the platelet endoperoxides which are intermediaries in the sequence of platelet prostaglandin synthesis. These results, therefore, suggest that part of the phenomenon of platelet hyperaggregability is intrinsic to the platelet and may involve platelet prostaglandin synthesis. The estimation of platelet malonyldialdehyde is a simple technique which appears to detect platelet hyperfunction.
Platelet Aggregation: Newly Quantified Using NonEmpirical Parameters
Authors: Nichols Alan R , Bosmann H Bruce
Published: August 2018

New methodology for a quantitative description of adenosine diphosphate (ADP)- induced human blood platelet aggregation in vitro is presented. The method uses electronic particle size analysis to determine the relative amounts of and distribution of sizes among platelets and aggregates after rapid termination of the events of ADP-induced aggregation by glutaraldehyde. Glutaraldehyde is found to preserve the state of platelets and aggregates in suspension unchanged for up to 48 h.

Descriptions of platelet aggregate sizes and amounts at many points during reversible and irreversible aggregation at 37° C as they occur in the Platelet Aggregometer are discussed. A new model of reversible platelet aggregation emerges revealing previously unrecognized details of both the aggregation and disaggregation phases of the phenomenon and establishing that disaggregation is not simply the ‘mirror image’ of aggregation. Furthermore, the reactive proportions of the platelet population under conditions of both ADP- induced reversible and irreversible aggregation are very similar, strongly suggesting that other factors are responsible for the observed large differences in aggregation rates and resulting aggregate sizes. Correlations between Platelet Aggregometer parameters and the aggregate size distributions are considered, and the first report of a correlation between the average platelet composition of particles in the aggregated suspensions and the absorbance change as recorded by the Aggregometer is made. Also, the relationship between particle concentration of a suspension of platelets and aggregates and the suspension absorbance is non-linear. Heretofore unrecognized limitations of the Platelet Aggregometer are revealed. Importantly, absorbance as measured by the Aggregometer does not uniquely represent the magnitude of formed aggregates.
Relationship Between Mepacrine-Labelled Dense Body Number, Platelet Capacity to Accumulate 14C-5-HT and Platelet Density in the Bernard-Soulier and Hermansky-Pudlak Syndromes
Authors: Rendu F , Nurden A T , Lebret M , Caen J P
Published: August 2018

We have used the mepacrine-labelling procedure to measure the dense body (serotonin storage organelle) content of the platelets of 2 hereditary disorders where abnormalities in dense body number were suspected. The platelets were incubated with mepacrine and examined by fluorescence microscopy. A mean number of 5.4 ± 0.8 (SD) dense bodies per platelet was calculated from the data obtained using platelets isolated from 40 normal human subjects. In contrast the platelets of 2 patients with the Bernard-Soulier syndrome contained an average of 14 and 17 labelled granules. This increase was associated with a much greater capacity of the platelets to accumulate 14C-5-HT. The opposite result was obtained using the platelets from 2 patients with the Hermansky-Pudlak syndrome which contained few granules labelled by mepacrine and took up less 14C-5-HT than normal human platelets. Centrifugation of the patients’ platelets on discontinuous sucrose gradients showed that the platelets of the 2 Bemard-Soulier patients were much denser than normal whereas a high proportion of low density platelets was observed in the Hermansky-Pudlak syndrome. These results further define the platelet abnormalities in the two syndromes and suggest that dense body number may be one of the factors governing platelet density.
Effects of Tsetse (Glossina morsitans morsitans Westw.) (Diptera: Glossinidae) Salivary Gland Homogenate on Coagulation and Fibrinolysis
Authors: Parker Kenneth R , Mant Michael J
Published: August 2018

The saliva of the tsetse, Glossina morsitans morsitans Westwood, has antithrombin anticoagulant activity and inhibits thrombin’s esterolytic activity. It has no other detectable anticoagulant properties. The anticoagulant elutes in a single peak on Sephadex fraction, is immediately acting, heat and storage stable, and has a molecular weight of 11-13,000. Unlike heparin it is not neutralized by protamine sulphate or toluidine blue and does not require the co-factor, antithrombin III, for optimal anticoagulant activity. It has similar properties to hirudin, but does not elute with a protein peak upon Sephadex fractionation and has a slightly different molecular weight. Salivary gland homogenates contained neither a plasminogen activator nor fibrinolytic activity. The sera of rabbits used to maintain tsetses, which contained precipitating antibodies against saliva, did not neutralize the salivary anticoagulant in vitro. The properties of this anticoagulant suggest that it might be a potentially useful antithrombotic agent in man.
Inhibition of ADP-Induced Platelet Aggregation by Dipyrone in Patients with Acute Myocardial Infarction
Authors: Weinberger Itzhak , Joshua Henry , Friedmann Jacov , Rahamim Saadia , Agmon Jacob
Published: August 2018

ADP induced platelet aggregation was investigated in 48 patients within three days of the first signs of acute myocardial infarction (AMI). Thirty six of them received 1 gram of dipyrone. Twelve patients who did not receive dipyrone served as controls.

Platelet aggregation was found severely inhibited in 11 patients who had received dipyrone up to 12 hours before investigation and moderately inhibited among 25 patients who were given the drug 12-24 hours prior to the investigation.

All the patients with AMI who did not receive dipyrone, exhibited a state of hyper- aggregability evidenced by the presence of a second phase of aggregation even with 0.5 μM ADP.

The inhibitory activity of dipyrone on the second phase of platelet aggregation resembles that of other non steroidal anti-inflammatory drugs.
A Simple Enzyme-Immunoassay (EIA) Test for Factor VIII-Related Antigen (VIIIAGN)
Authors: Ness Paul M , Perkins Herbert A
Published: August 2018

An enzyme immunoassay (EIA) system has been developed to measure factor VIII- related antigen (VIIIAGN). This assay gives similar results to the commonly used Laurell electroimmunodiffusion (EID) assay for VIIIAGN as shown by comparison of both techniques with samples from healthy controls, patients with hemophilia A, and patients with von Willebrand’s disease. The assay also has a greater precision than the EID technique as demonstrated by multiple assays of aliquots of a single sample. The use of this EIA test for VIIIAGN is simple and employs inexpensive reagents and equipment. The use of expensive antisera is minimized. EIA for VIIIAGN has the advantage of increased sensitivity compared to Laurell EIA.
Crosslinking of Monomeric Fibrin by Factor XIIIa
Authors: Dardik Beatriz N , Shainoff John R
Published: August 2018

The acceleration of crosslinking that accompanies transformation of fibrinogen to fibrin has been suggested to arise from the aggregation of the fibrinogen rather than a change in affinity for the crosslinking enzyme, factor Xllla. A test of the importance of aggregation has been obtained from studies on the effect of removing fibrinopeptide B from fibrinogen. Specific removal of fibrinopeptide B through reaction of human fibrinogen with copperhead venom procoagulant enzyme at low temperatures yields fibrin which dissolves on warming to 37° C and dissociates fully into monomers on dilution to a concentration below 0.2 mg/ml. When this fibrin and a fibrin lacking both fibrinopeptides A and B were compared at high concentrations above 2 mg/ml which favored a high degree of aggregation of both forms, they underwent crosslinking at similar rates that were approximately thirty two (25 ± 0.5) times faster than crosslinking of fibrinogen. However, at concentrations below 0.2 mg/ml, the fibrin lacking B alone underwent crosslinking at only one sixty-fourth of the rate of fibrin lacking both fibrinopeptides A and B. The relatively slow crosslinking in dilute solutions of the fibrin lacking fibrinopeptide B appeared due to the unique dissociation of this fibrin into monomers at low concentrations. As judged from both the rate of stable clot formation and the rate of formation of dimeric y-chains, crosslinking of the monomers did not differ from that of fibrinogen.
Comparative Histochemical Studies on Fibrinolysis in Whole Organs and Isolated Tissue Layers
Authors: Smokovitis Athanasios
Published: August 2018

Using Todd’s technique for the detection of plasminogen activator and Noordhoek Hegt and Brakman’s method for inhibitors of fibrinolysis, rat tissues were studied, both in sections of whole organs and as separated tissue layers. Whole organ preparations showed less fibrinolytic activity and poorer localisation of inhibitor, because of a widespread diffusion of the inhibitor from tissue layers rich in inhibitor during the histochemical procedures.

It is concluded that when using histochemical methods both agents are best studied in separated layers of the organ to avoid the masking effects of diffused inhibitor.
Outcome of Ventral Fusion of Two or Three Cervical Vertebrae with a Locking Compression Plate for the Treatment of Cervical Stenotic Myelopathy in Eight Horses
Authors: Fürst Anton , Ranninger Elisabeth , Suárez Sánchez-Andrade José , Kümmerle Jan , Kühnle Christoph
Published: August 2018

Objectives It was recently shown that biomechanical stability achieved with a locking compression plate (LCP) for ventral cervical fusion in horses is similar to the commonly used Kerf cut cylinder. The advantages of the LCP system render it an interesting implant for this indication. The goal of this report was to describe surgical technique, complications and outcome of horses that underwent ventral fusion of two or three cervical vertebrae with an LCP.

Methods Medical records of eight horses were reviewed for patient data, history, preoperative grade of ataxia, diagnostic imaging, surgical technique and complications. Follow-up information was obtained including clinical re-examination and radiographs whenever possible.

Results Two (n = 5) or 3 (n = 3) cervical vertebrae were fused in a mixed population with a median age of 9 months, median weight of 330 kg and median grade of ataxia of 3/5. A narrow 4.5/5.0 LCP (n = 6), a broad 4.5/5.0 LCP (n = 1) and a human femur 4.5/5.0 LCP (n = 1) were applied. Two horses were re-operated due to implant loosening. Six patients developed a seroma. Long-term complications included ventral screw migration in four, spinal cord injury in one and plate breakage in two horses at 720 to 1116 days after surgery. Outcome was excellent in three, good in four, poor in one patient.

Clinical Significance The use of an LCP for ventral cervical vertebral fusion is associated with good clinical results. However, a careful surgical technique is required to further reduce the complication rate.
Evaluation of Modified Techniques for Toggle Pin Repair of Coxofemoral Luxation in Dogs: A Cadaveric Study
Authors: Bugbee Suzanne , Strasberg Jason , Franklin Samuel , Helmick Jacob
Published: August 2018

Objectives The primary objective was to assess acetabular articular cartilage damage when an acetabular tunnel is drilled by passing the drill bit through the femoral tunnel. The second objective was to assess the success rate of passing the toggle through the femoral and acetabular tunnels in a single manoeuvre using a toggle delivery device.

Methods Open bilateral coxofemoral luxations in 16 canine cadavers were repaired by toggle pin technique by a surgical resident (n = 8) and a diplomate surgeon (n = 8). In one hip of each cadaver, the acetabular tunnel was drilled through the femoral tunnel and the toggle was passed in a single manoeuvre using the delivery device. In the contralateral hip, the tunnels were drilled separately, and the toggle was passed through each tunnel separately (resident) or in a single manoeuvre (surgeon). Pelves were examined for acetabular cartilage damage and toggle placement.

Results Cartilage damage did not occur with independent drilling of the acetabulum but occurred in 6/16 hips in which the acetabulum was drilled via the femoral tunnel. Successful deployment of the toggle was obtained in 24/24 hips in which the toggle was passed through the femoral and acetabular tunnels simultaneously using the delivery device, regardless of how the acetabular tunnel was drilled.

Clinical Significance Drilling the acetabular tunnel through the femoral tunnel risks damaging the acetabular cartilage. Success was consistently obtained when passing the toggle through the femoral and acetabular tunnels simultaneously using the toggle delivery device.
Atmosphere-Land Bridge between the Pacific and Tropical North Atlantic SST’s through the Amazon River basin during the 2005 and 2010 droughts
Authors: Builes-Jaramillo Alejandro , Ramos Antônio M. T. , Poveda Germán
Published: August 2018

The present work uses a new approach to causal inference between complex systems called the Recurrence Measure of Conditional Dependence (RMCD) based on the recurrence plots theory, in order to study the role of the Amazon River basin (AM) as a land-atmosphere bridge between the Niño 3.0 region in the Pacific Ocean and the Tropical North Atlantic. Two anomalous droughts in the Amazon River basin were selected, one mainly attributed to the warming of the Tropical North Atlantic (2005) and the other to a warm phase of El Niño–Southern Oscillation (2010). The results of the RMCD analysis evidence the distinctive behavior in the causal information transferred between the two oceanic regions during the two extreme droughts, suggesting that the land-atmosphere bridge operating over the AM is an active hydroclimate mechanism at interannual timescales, and that the RMCD analysis may be an ancillary resort to complement early warning systems.
Sleep-wake detection using recurrence quantification analysis
Authors: Parro V. C. , Valdo L.
Published: August 2018

Actigraphy is a method for monitoring the movements of the nondominant arm, and the technology has found applications ranging from clinical devices to smart wristbands. Time series obtained from actigraphy data is used in chronobiology to define the sleep-wake cycle, as well as in sleep medicine to evaluate an individual’s sleep quality. In the study described in this paper, an algorithm based on recurrence quantification analysis (RQA) was applied to a time series obtained from a commercial actigraph, which was used to collect raw data alongside polysomnography (PSG), generally considered as the gold standard for assessing sleep quality. The central hypothesis is that transitions between sleep and wakefulness are not purely random events, but are strongly influenced by two internal processes: the homeostatic pressure and the circadian cycle. On the basis of this premise, application of RQA to time series as an estimator of this system should lead to improved results and allow more reliable investigations than a purely empirical approach. To compare the results from the RQA algorithm and those from PSG, we present a detailed statistical analysis involving a bias evaluation of the two methods following an approach suggested by Bland and Altman, a comparison of data processed using the kappa coefficient, and a comparison of consolidated sleep quality data using the p-value.
Exploiting nonlinearity of the speech production system for voice disorder assessment by recurrence quantification analysis
Authors: Vieira Vinícius J. D. , Costa Silvana C. , Correia Suzete L. N. , Lopes Leonardo W. , Costa Washington C. de A. , de Assis Francisco M.
Published: August 2018

This work summarizes the research related to digital speech signal processing with recurrence quantification analysis (RQA) applied to voice disorder assessment. The main motivation for these studies is the fact that RQA is able to exploit the nonlinear dynamical nature of the speech production system. Due to the use of recurrence quantification measures to represent the behavior of speech signals, promising results were obtained in the characterization and classification of laryngeal pathologies and voice disorders. These contributions may help one to evaluate the usability and efficiency of RQA in vocal disorder assessment.
Using recurrence plots for the analysis of the nonlinear dynamical response of iron passivation-corrosion processes
Authors: Valavanis Dimitrios , Spanoudaki Dimitra , Gkili Chrysanthi , Sazou Dimitra
Published: August 2018

Recurrence plots (RPs) and recurrence quantification analysis (RQA) are used in this work to study different nonlinear dynamical regimes emerging in an electrochemical system, namely, the electrodissolution-passivation of iron in chloride-containing sulfuric acid solutions. Current oscillations at different applied potentials and chloride concentrations exhibit bifurcations from periodic to complex (bursting) periodic and aperiodic or chaotic behaviors, associated with different dissolution states of iron. The clarification of these transitions is essential to understand the type of corrosion (uniform or localized) taking place as well as the underlying mechanisms governing the stability of the metal. The RQA reveals that the predictability of the chloride-perturbed Fe|0.75M H2SO4 system strongly depends on the chloride concentration and the applied potential. At relatively low chloride concentrations, RQA measures, based on vertical and diagonal structures in RPs, display a decrease upon the breakdown of the passivity on iron and the initiation of localized corrosion (pitting). Phases of pitting corrosion (propagation/growth and unstable pitting) that followed pit initiation are discerned by keen changes of complexity measures upon varying the applied potential. At higher chloride concentrations, the evolution of RQA measures with the potential signifies a transition from the passive-active state dissolution to the polishing state dissolution of iron inside pits. The increase of the applied potential at late stages of pitting corrosion increases the nonlinear correlations and thus the complexity of the system decreases, which corroborates the RQA.
Existence of internal domains in (Bi0.5La0.5FeO3)(1-x)–(Ba0.7Sr0.3TiO3)x solid solution and their effects on magnetic and dielectric behaviour
Authors: Vansutre Sandeep , Mukherjee S. , Kaushik S. D. , Verma A. , Yadav Ramesh , Mandal B. P. , Babu P. D. , Siruguri V. , Goyal P. S. , Radha S.
Published: August 2018

A significant experimental effort has been undertaken to evaluate the doping effect of La3+at Bi-site in solid solutions of BiFeO3 (BFO) and Ba0.7Sr0.3TiO3 (BST) through various techniques like x-ray diffraction, magnetic measurements, and frequency and/or temperature dependent impedance spectroscopy. The magnetic isotherm at room temperature in La doped BFO (BLFO)-BST solid solution indicates weak ferromagnetism due to improvement in the homogeneous canted spin structure. The elusive nano-sized domain structure inside the grains of 40% BST co-doped BLFO was observed by a scanning electron microscopy technique. The domains and domain boundaries are generally formed inside the grain due to strained/unstrained lattice defects and/or mismatch with the substitution of ions of different sizes at the A and B sites. An equivalent circuit model (internal barrier layer capacitor), based on domain, domain boundary, and grain boundary relaxations, has been established to justify the enhancement of the dielectric response with BST concentrations.
Spin thermoelectric properties based on a Rashba triple-quantum-dot ring
Authors: Li Haidong , Wang Yuan , Liu Shaohui , kang Xiubao , Ding Jun , Hao Haoshan
Published: August 2018

Based on a Rashba triple-quantum-dot ring, we theoretically investigate spin thermoelectric properties by using the nonequilibrium Green's function method. Our results show that thermoelectric properties are strongly influenced by the Rashba effect. The underlying reason is the antiresonance effect from Rashba spin-orbit interaction. When the magnetic field and Rashba phase factor satisfy a certain relationship, the value of the spin- dependent Seebeck coefficient alternates between its maximum and zero, and then a pure spin-dependent thermoelectric generator can be obtained. Moreover, we also find that the on-site Coulomb interaction is helpful to obtain a large amplitude for the figure of merit and a high Seebeck coefficient.
Electron emission by long and short wavelength lasers: Essentials for the design of plasmonic photocathodes
Authors: Forati Ebrahim , Sievenpiper Dan
Published: August 2018

The theory of electron emission by metallic photocathodes under the exposure of long wavelength lasers will be studied. Photon energy in long wavelength lasers is less than the work function of the photocathode's material and can only emit electrons via tunneling through the potential barrier. The optical resonance effects (e.g., plasmonic resonances) will be studied as an improvement to the performance of photocathodes. This paper is intended to provide self-sufficient materials to design optical resonant surfaces (e.g., metasurfaces) for electron emission applications.
Air molecules in XPbI3 (X=MA, FA, Cs) perovskite: A degradation mechanism based on first-principles calculations
Authors: Jiang Chenghuan , Wang Yitian , Zhou Rongqing , Wang Haowei , Chen Qian
Published: August 2018

The power conversion efficiency of organic–inorganic halide perovskite solar cells is exceeding 22%. However, their potential for low cost and facile fabrication process needs to overcome barriers related to environmental stability and compatibility. Herein, using first-principles calculations, we studied the structural and electronic properties of air molecules (H2O, O2, N2, and CO2) in MAPbI3 and FAPbI3. Both formation energy and electronic band structures show large differences for H2O and O2 in these perovskites. In addition, the stability of inorganic perovskite, CsPbI3, was investigated and compared with the aforementioned organic ones. Based on the degradation mechanisms revealed by crosswise comparative analysis here, possible routes can be developed to stabilize the hybrid perovskite solar cells and thus accelerate their commercial applications.
Effect of interlayer space on the structure and Poisson's ratio of a graphene/MoS2 tubular van der Waals heterostructure
Authors: Tan Ya-Wen , Jiang Jin-Wu
Published: August 2018

We propose a tubular van der Waals heterostructure by rolling up graphene and MoS2 atomic layers into a tubular form. We show that the interlayer space of this heterostructure can be varied in a specific range. This specific range is related to the interlayer van der Waals force, the ultrahigh in-plane stiffness and small bending modulus of graphene, and the brittle characteristic properties of MoS2. This variability of the interlayer space can be utilized to efficiently tune the mechanical properties of the tubular van der Waals heterostructure. More specifically, we demonstrate that the Poisson's ratio of the tubular van der Waals heterostructure can be manipulated by a factor of two by varying the interlayer space in the range 1.44–4.44 Å. This work provides a basis for applications of a new member of the van der Waals heterostructure family with a tunable Poisson's ratio.
The tunneling magnetoresistance in 2D topological superconductor hybrid structure
Authors: Wu Hai-Bin , Zhang Ying-Tao , Liu Jian-Jun
Published: August 2018

Based on the Green's function method and tight-binding model, we have investigated tunneling magnetoresistance (TMR) in a two-dimensional quantum anomalous Hall insulator (QAHI)/topological superconductor (TSC)/QAHI hybrid structure with its Chern number N = 1 and N = 0 in the central TSC region. It is found that the TMR effect can emerge in our proposed structure. In the presence of the chiral gapless Majorana edge state, the 100% TMR ratio is robust to disorder and is independent of the length of TSC. Further calculations show that the TMR effect could be adjusted by the relative angle between magnetizations of left and right QAHI electrodes and magnetization strength. In addition, we also calculate the TMR effect in the QAHI/TSC/QAHI hybrid structure with its Chern number N = 2 in the central TSC region. We found that our conclusions are still applicable.
Active localization of wave propagation in elastic beams using periodic placement of piezoelectric actuator/sensor pairs
Authors: Li Fengming , Zhang Chuanzeng
Published: August 2018

A novel strategy is proposed to investigate the active localization of elastic waves in beams with periodically placed piezoelectric actuator/sensor pairs under random feedback control gains. The randomly disordered active stiffness is obtained and periodically added to the beam. The localization factor is introduced and defined by using the eigenvalues of the transfer matrices. From this investigation, it is found that the active localization of elastic waves in beams can be realized and the propagation of elastic waves in certain designated frequency ranges can be actively controlled. Consequently, the feedback control gains can be intentionally designed to be random so that the frequency band-gaps can be actively broadened and the ability for the structural vibration isolation and noise reduction can also be enhanced.
Instability of crystal/melt interface in Si-rich SiGe
Authors: Mokhtari M. , Fujiwara K. , Takakura G. , Maeda K. , Koizumi H. , Nozawa J. , Uda S.
Published: August 2018

An investigation was carried out into the instability of the crystal/melt interface in Si-rich SiGe, and the effects of the Ge concentration and growth velocity on the periodicity of zigzag facets at the interface were determined. It was found that the periodicity at the onset of instability became shorter with the increasing growth velocity and Ge concentration.