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Sample records for light coagulation

  1. Could light meal jeopardize laboratory coagulation tests?

    PubMed Central

    Lima-Oliveira, Gabriel; Salvagno, Gian Luca; Lippi, Giuseppe; Danese, Elisa; Gelati, Matteo; Montagnana, Martina; Picheth, Geraldo; Guidi, Gian Cesare

    2014-01-01

    Background: Presently the necessity of fasting time for coagulation tests is not standardized. Our hypothesis is that this can harm patient safety. This study is aimed at evaluating whether a light meal (i.e. breakfast) can jeopardize laboratory coagulation tests. Materials and methods: A blood sample was firstly collected from 17 fasting volunteers (12 h). Immediately after blood collection, the volunteers consumed a light meal. Then samples were collected at 1, 2 and 4 h after the meal. Coagulation tests included: activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen (Fbg), antithrombin III (AT), protein C (PC) and protein S (PS). Differences between samples were assessed by Wilcoxon ranked-pairs test. The level of statistical significance was set at P < 0.05. Mean % differences were determined and differences between and baseline and 1, 2 and 4h samples were compared with reference change value (RCV). Results: A significantly higher % activity of AT was observed at 1 h and 4 h after meal vs. baseline specimen [113 (104–117) and 111 (107–120) vs. 109 (102–118), respectively; P = 0.029 and P = 0.016]. APTT at 2 h was found significantly lower than baseline samples [32.0 (29.9–34.8) vs. 34.1 (32.2–35.2), respectively; P = 0.041]. The results of both Fbg and PS tests were not influenced by a light meal. Furthermore, no coagulation tests had significant variation after comparison with RCV. Conclusion: A light meal does not influence the laboratory coagulation tests we assessed, but we suggest that the laboratory quality managers standardize the fasting time for all blood tests at 12 hours, to completely metabolize the lipids intake. PMID:25351352

  2. Could light meal jeopardize laboratory coagulation tests?

    PubMed

    Lima-Oliveira, Gabriel; Salvagno, Gian Luca; Lippi, Giuseppe; Danese, Elisa; Gelati, Matteo; Montagnana, Martina; Picheth, Geraldo; Guidi, Gian Cesare

    2014-01-01

    Presently the necessity of fasting time for coagulation tests is not standardized. Our hypothesis is that this can harm patient safety. This study is aimed at evaluating whether a light meal (i.e. breakfast) can jeopardize laboratory coagulation tests. A blood sample was firstly collected from 17 fasting volunteers (12 h). Immediately after blood collection, the volunteers consumed a light meal. Then samples were collected at 1, 2 and 4 h after the meal. Coagulation tests included: activated partial thromboplastin time (APTT), prothrombin time (PT), fibrinogen (Fbg), antithrombin III (AT), protein C (PC) and protein S (PS). Differences between samples were assessed by Wilcoxon ranked-pairs test. The level of statistical significance was set at P < 0.05. Mean % differences were determined and differences between and baseline and 1, 2 and 4h samples were compared with reference change value (RCV). A significantly higher % activity of AT was observed at 1 h and 4 h after meal vs. baseline specimen [113 (104-117) and 111 (107-120) vs. 109 (102-118), respectively; P = 0.029 and P = 0.016]. APTT at 2 h was found significantly lower than baseline samples [32.0 (29.9-34.8) vs. 34.1 (32.2-35.2), respectively; P = 0.041]. The results of both Fbg and PS tests were not influenced by a light meal. Furthermore, no coagulation tests had significant variation after comparison with RCV. A light meal does not influence the laboratory coagulation tests we assessed, but we suggest that the laboratory quality managers standardize the fasting time for all blood tests at 12 hours, to completely metabolize the lipids intake.

  3. Effect of coagulation on laser light distribution in myocardial tissue

    NASA Astrophysics Data System (ADS)

    Agah, Ramtin; Sheth, Devang; Motamedi, Massoud

    1991-05-01

    The changes in total reflection and transmission of porcine myocardium due to thermal coagulation were measured during tissue heating in a temperature-controlled water bath, at different temperature ranging between 54 degree(s)-63 degree(s)C. At 633 nm, the measurements yield a picture of continuous decrease in transmission and a peak with a subsequent fall (approximately 10% from the peak) in reflection measurements of the tissue during coagulation process. Utilizing these measurements and an inverse solution to the radiative transfer equation, the optical properties of tissue, absorption, (mu)a, and effective scattering, (mu)s=(mu)s(1-g) were calculated. A one-dimensional diffusion approximation was used to demonstrate the effects of thermally induced changes in the optical properties of tissue on light distribution in tissue. The pattern of changes in (mu)a and (mu)s seem to indicate that several simultaneous rate processes may be responsible for tissue coagulation. A postulate is put forward to use one such rate process to characterize threshold thermal damage to porcine myocardium and the accompanying protein denaturation.

  4. COAGULATION

    EPA Science Inventory

    This chapter reports on the efforts of the USEPA to study conventional and enhanced coagulation for the control of disinfection by-products (DBPs) in drinking water. It examines the control of DBPs like trihalomethanes, haloacetic acids and the surrogate total organic halide in t...

  5. A high affinity monoclonal antibody recognizing the light chain of human coagulating factor VII.

    PubMed

    Sarial, Sheila; Asadi, Farzad; Jeddi-Tehrani, Mahmood; Hadavi, Reza; Bayat, Ali Ahmad; Mahmoudian, Jafar; Taghizadeh-Jahed, Masoud; Shokri, Fazel; Rabbani, Hodjattallah

    2012-12-01

    Factor VII (FVII) is a serine protease-coagulating element responsible for the initiation of an extrinsic pathway of clot formation. Here we generated and characterized a high affinity monoclonal antibody that specifically recognizes human FVII. Recombinant human FVII (rh-FVII) was used for the production of a monoclonal antibody using BALB/c mice. The specificity of the antibody was determined by Western blot using plasma samples from human, mouse, sheep, goat, bovine, rabbit, and rat. Furthermore, the antibody was used to detect transiently expressed rh-FVII in BHK21 cell line using Western blot and sandwich ELISA. A mouse IgG1 (kappa chain) monoclonal antibody clone 1F1-B11 was produced against rh-FVII. The affinity constant (K(aff)) of the antibody was calculated to be 6.4×10(10) M(-1). The antibody could specifically recognize an epitope on the light chain of hFVII, with no reactivity with factor VII from several other animals. In addition, transiently expressed rh-FVII in BHK21 cells was recognized by 1F1-B11. The high affinity as well as the specificity of 1F1-B11 for hFVII will facilitate the affinity purification of hFVII and also production of FVII deficient plasma and minimizes the risk of bovine FVII contamination when fetal bovine serum-supplemented media are used for production and subsequent purification of rh-FVII.

  6. [Ssp DnaB intein-mediated ligation of heavy and light chains of coagulation factor VIII in Escherichia coli].

    PubMed

    Zhu, Fuxiang; Liu, Zelong; Qu, Huige; Xin, Xiaolin; Dong, Hongxin; Liu, Xiangqin

    2009-07-01

    We studied the ligation of coagulation factor VIII heavy and light chains in Escherichia coli by utilizing the intein-mediated protein trans-splicing. A B-domain deleted factor VIII (BDD-FVIII) gene was broken into two halves of heavy and light chains before Ser1657 which meets the splicing required conserved residue and then fused to 106 and 48 amino acid-containing N-part termed Int-N and C-part termed Int-C coding sequences of split mini Ssp DnaB intein respectively. These two fusion genes were constructed into a prokaryotic expression vector pBV220. Through induction for expression of recombinant protein it displayed an obvious protein band as predicted size of BDD-FVIII protein on SDS-PAGE gel. Western blotting using factor VIII specific antibodies confirmed that this protein band is BDD-FVIII produced by protein trans-splicing. It demonstrated that the heavy and light chains of BDD-FVIII can be efficiently ligated with the Ssp DnaB intein-mediated protein trans-splicing. These results provided evidence for encouraging our ongoing investigation with intein as a means in dual AAV vectors carrying the factor VIII gene to overcome the packaging size limitation of a single AAV vector in hemophilia A gene therapy.

  7. New clotting disorders that cast new light on blood coagulation and may play a role in clinical practice.

    PubMed

    Girolami, A; Cosi, E; Ferrari, S; Lombardi, A M; Girolami, B

    2017-03-01

    Recently several variants of clotting factors have shown a peculiar behavior so that they appear as new defects. The factors involved are FII, FV and FIX. Prothrombin deficiency is usually associated with bleeding. Recently a few prothrombin abnormalities involving Arg396 mutations, have been demonstrated to show antithrombin resistance with the consequent appearance of a thrombophilic state and venous thromboses in young age. The same is true for an abnormal FIX (FIX Padua). The thrombotic manifestations in the latter condition are also venous. The abnormal FIX (FIX Padua) is characterized by a great increase in FIX activity whereas FIX antigen is only slightly increased. The condition is due to an Arg338Lys mutation. The increased intrinsic clotting activity of this abnormal FIX is being investigated as a useful therapeutic approach in homophile B patients. Another new clotting disorder is represented by two abnormal FV (FV East Texas and FV Amsterdam). These are characterized by a deletion of part of the B domain of FV resulting in a "short" FV. The condition is characterized by a mild bleeding tendency due to high levels of Tissue Factor pathway inhibitor. The "short" factor V is in fact resistant to the action of Tissue Factor pathway inhibitor which is sharply increased in these patients. These new clotting entities have again demonstrated that the study of patients who show a tendency to venous thrombosis or a mild bleeding condition that cannot be explained on the basis of our current concepts of blood coagulation, may represent "new" coagulation disorders. All persons interested in thrombotic or hemorrhagic disorders should be informed about these new clinical and laboratory conditions.

  8. Assessing blood coagulation status with laser speckle rheology

    PubMed Central

    Tripathi, Markandey M.; Hajjarian, Zeinab; Van Cott, Elizabeth M.; Nadkarni, Seemantini K.

    2014-01-01

    We have developed and investigated a novel optical approach, Laser Speckle Rheology (LSR), to evaluate a patient’s coagulation status by measuring the viscoelastic properties of blood during coagulation. In LSR, a blood sample is illuminated with laser light and temporal speckle intensity fluctuations are measured using a high-speed CMOS camera. During blood coagulation, changes in the viscoelastic properties of the clot restrict Brownian displacements of light scattering centers within the sample, altering the rate of speckle intensity fluctuations. As a result, blood coagulation status can be measured by relating the time scale of speckle intensity fluctuations with clinically relevant coagulation metrics including clotting time and fibrinogen content. Our results report a close correlation between coagulation metrics measured using LSR and conventional coagulation results of activated partial thromboplastin time, prothrombin time and functional fibrinogen levels, creating the unique opportunity to evaluate a patient’s coagulation status in real-time at the point of care. PMID:24688816

  9. Coagulation dynamics of a blood sample by multiple scattering analysis

    NASA Astrophysics Data System (ADS)

    Faivre, Magalie; Peltié, Philippe; Planat-Chrétien, Anne; Cosnier, Marie-Line; Cubizolles, Myriam; Nougier, Christophe; Négrier, Claude; Pouteau, Patrick

    2011-05-01

    We report a new technique to measure coagulation dynamics on whole-blood samples. The method relies on the analysis of the speckle figure resulting from a whole-blood sample mixed with coagulation reagent and introduced in a thin chamber illuminated with a coherent light. A dynamic study of the speckle reveals a typical behavior due to coagulation. We compare our measured coagulation times to a reference method obtained in a medical laboratory.

  10. Coagulation and metastasis: what does the experimental literature tell us?

    PubMed

    Gil-Bernabé, Ana M; Lucotti, Serena; Muschel, Ruth J

    2013-08-01

    Inhibition of coagulation greatly limits cancer metastasis in many experimental models. Cancer cells trigger coagulation, through expression of tissue factor or P-selectin ligands that have correlated with worse prognosis in human clinical studies. Cancer cells also affect coagulation through expression of thrombin and release of microparticles that augment coagulation. In the cancer-bearing host, coagulation facilitates tumour progression through release of platelet granule contents, inhibition of Natural Killer cells and recruitment of macrophages. We are revisiting this literature in the light of recent studies in which treatment of clinical cohorts with anticoagulant drugs led to diminished metastasis. © 2013 John Wiley & Sons Ltd.

  11. STUDIES IN BLOOD COAGULATION

    PubMed Central

    Van Allen, C. M.

    1927-01-01

    Description is given of changes in blood coagulability found in diseases of the rabbit, including malignant tumor, spontaneous infections, non-bacterial diseases and lesions, and hemorrhagic states specifically induced. The changes involved variously the time of onset of blood coagulation, clot formation rate and the rate and extent of clot retraction. PMID:19869243

  12. Coagulation in chaotic flows

    SciTech Connect

    Muzzio, F.J.; Ottino, J.M.

    1988-09-01

    We study coagulation in the flow field of a time-periodic deterministic chaotic flow and focus on the simplest case: point particles convected without diffusion and allowed to coagulate with probability 1 when the distance is less than d. An analysis of the underlying physics is presented. Under ''well-mixed'' conditions the system behaves as if the particles were moved by Brownian motion, and a simple kinetic model describes the main results. The poorly mixed case is considerably more complex. Spatial inhomogeneities result from competition between the rate of coagulation and mixing, and trapping and leaking of clusters due to Kolmogorov-Arnold-Moser surfaces.

  13. Dust coagulation in ISM

    NASA Technical Reports Server (NTRS)

    Chokshi, Arati; Tielens, Alexander G. G. M.; Hollenbach, David

    1989-01-01

    Coagulation is an important mechanism in the growth of interstellar and interplanetary dust particles. The microphysics of the coagulation process was theoretically analyzed as a function of the physical properties of the coagulating grains, i.e., their size, relative velocities, temperature, elastic properties, and the van der Waal interaction. Numerical calculations of collisions between linear chains provide the wave energy in individual particles and the spectrum of the mechanical vibrations set up in colliding particles. Sticking probabilities are then calculated using simple estimates for elastic deformation energies and for the attenuation of the wave energy due to absorption and scattering processes.

  14. [Coagulation disorders in cirrhosis].

    PubMed

    Téllez-Avila, Felix I; Chávez-Tapia, Norberto C; Torre-Delgadillo, Aldo

    2007-01-01

    The liver plays a central role in the clotting process. In this organ are sintetizated the major part of the coagulation factors. Historically, was considered that alteration in liver function causes important bleeding disorders. However, actual evidence is not in agreement with this asseveration. Decreased synthesis of clotting and inhibitor factors, decrease clearance of activated factors, quantitative and qualitative platelet defects, hyperfibrinolysis and intravascular coagulation are some of the defects observed in liver diseases. Thrombotic events, even if rare in cirrhotic patients, occur manly in the portal and mesenteric veins. The aim of the present work is to review the present evidence in coagulation disorders and liver disease.

  15. The Mechanisms of Coagulation.

    ERIC Educational Resources Information Center

    Kurtz, Richard; Jesty, Jolyon

    1994-01-01

    Several topics such as heart disease, strokes, biochemical reactions, blood components, and genetics can be related to blood clotting. Introduces a simple, safe and inexpensive hands-on demonstration using bovine (cattle) blood plasma of normal and abnormal coagulation. (ZWH)

  16. [Diagnostic of blood coagulation].

    PubMed

    Barthels, M

    2008-12-01

    A survey is given on the peculiar characteristics of laboratory methods for analyzing the blood coagulation system with special regard to the preanalytical, analytical and postanalytical phase. Routinely used methods are described.

  17. The Mechanisms of Coagulation.

    ERIC Educational Resources Information Center

    Kurtz, Richard; Jesty, Jolyon

    1994-01-01

    Several topics such as heart disease, strokes, biochemical reactions, blood components, and genetics can be related to blood clotting. Introduces a simple, safe and inexpensive hands-on demonstration using bovine (cattle) blood plasma of normal and abnormal coagulation. (ZWH)

  18. Coagulation and sepsis.

    PubMed

    Levi, Marcel; van der Poll, Tom

    2017-01-01

    Severe sepsis is almost invariably associated with systemic activation of coagulation. There is ample evidence that demonstrates a wide-ranging cross-talk between hemostasis and inflammation, which is probably implicated in the pathogenesis of organ dysfunction in patients with sepsis. Inflammation not only leads to initiation and propagation of coagulation activity, but coagulation also markedly influences inflammation. Molecular mechanisms that play a role in inflammation-induced effects on coagulation have been recognized in much detail. Pro-inflammatory cells and cyto- and chemokines can activate the coagulation system and downregulate crucial physiological anticoagulant mechanisms. Initiation of coagulation activation and consequent thrombin generation is caused by expression of tissue factor on activated monocytes and endothelial cells and is ineffectually offset by tissue factor pathway inhibitor. At the same time, endothelial-associated anticoagulant pathways, in particular the protein C system, is impaired by pro-inflammatory cytokines. Also, fibrin removal is severely obstructed by inactivation of the endogenous fibrinolytic system, mainly as a result of upregulation of its principal inhibitor, plasminogen activator inhibitor type 1 (PAI-1). Increased fibrin generation and impaired break down lead to deposition of (micro)vascular clots, which may contribute to tissue ischemia and ensuing organ dysfunction. The foundation of the management of coagulation in sepsis is the explicit and thorough treatment of the underlying disorder by antibiotic treatment and source control measures. Adjunctive strategies focused at the impairment of coagulation, including anticoagulants and restoration of physiological anticoagulant mechanisms, may supposedly be indicated and have been found advantageous in experimental and initial clinical trials.

  19. [Acquired coagulant factor inhibitors].

    PubMed

    Nogami, Keiji

    2015-02-01

    Acquired coagulation factor inhibitors are an autoimmune disease causing bleeding symptoms due to decreases in the corresponding factor (s) which result from the appearance of autoantibodies against coagulation factors (inhibitor). This disease is quite different from congenital coagulation factor deficiencies based on genetic abnormalities. In recent years, cases with this disease have been increasing, and most have anti-factor VIII autoantibodies. The breakdown of the immune control mechanism is speculated to cause this disease since it is common in the elderly, but the pathology and pathogenesis are presently unclear. We herein describe the pathology and pathogenesis of factor VIII and factor V inhibitors. Characterization of these inhibitors leads to further analysis of the coagulation process and the activation mechanisms of clotting factors. In the future, with the development of new clotting examination method (s), we anticipate that further novel findings will be obtained in this field through inhibitor analysis. In addition, detailed elucidation of the coagulation inhibitory mechanism possibly leading to hemostatic treatment strategies for acquired coagulation factor disorders will be developed.

  20. [Blood coagulation in hyperthermia].

    PubMed

    Zwierzina, W D; Herold, M; Günther, R; Kunz, F

    1980-01-01

    Young healthy volunteers were treated with physical hyperthermia (baths) in order to investigate changes in blood coagulation. Such therapy is used in the treatment of rheumatic diseases. Single hot baths (mean body temperature 38,2-39,9 degrees C) resulted in a rise of fibrinogen, factors IX and XII, maximal amplitude of the thrombelastogram and hemoglobin and in a decrease of plasminogen. In a series of hypothermic baths no additional changes of coagulation or fibrinolysis could be found. The results suggest that hyperthermia causes a tendency to thrombosis.

  1. Asthma and coagulation.

    PubMed

    de Boer, J Daan; Majoor, Christof J; van 't Veer, Cornelis; Bel, Elisabeth H D; van der Poll, Tom

    2012-04-05

    Asthma is a chronic airway disease characterized by paroxysmal airflow obstruction evoked by irritative stimuli on a background of allergic lung inflammation. Currently, there is no cure for asthma, only symptomatic treatment. In recent years, our understanding of the involvement of coagulation and anticoagulant pathways, the fibrinolytic system, and platelets in the pathophysiology of asthma has increased considerably. Asthma is associated with a procoagulant state in the bronchoalveolar space, further aggravated by impaired local activities of the anticoagulant protein C system and fibrinolysis. Protease-activated receptors have been implicated as the molecular link between coagulation and allergic inflammation in asthma. This review summarizes current knowledge of the impact of the disturbed hemostatic balance in the lungs on asthma severity and manifestations and identifies new possible targets for asthma treatment.

  2. Coagulation in Liver Disease.

    PubMed

    Hoffman, Maureane

    2015-07-01

    The liver plays a key role in hemostasis as the site of synthesis of many of the proteins involved in the coagulation, antithrombotic and fibrinolytic systems that interact to both establish hemostasis, and preventing thrombosis. The common laboratory tests, prothrombin time (PT) and activated partial thromboplastin time (aPTT), evolved from studies of plasma clotting in test tubes. Such studies laid the basis for the coagulation cascade model of hemostasis. However, thought has evolved to place a greater emphasis on the active roles of cells in localizing and regulating hemostasis. The PT and aPTT do not reflect the roles of cellular elements in hemostasis, nor do they reflect the crucial roles of antithrombotic and fibrinolytic systems. Thus, though the PT may indeed reflect the synthetic capacity of the liver, it does not accurately reflect the risk of bleeding or thrombosis in patients with liver failure.

  3. Argon plasma coagulation

    PubMed Central

    Zenker, Matthias

    2008-01-01

    Argon Plasma Coagulation (APC) is an application of gas discharges in argon in electrosurgery, which is increasingly used especially in endoscopy. The major application fields are haemostasis, tissue devitalization and tissue reduction. This review describes the physics and technology of electrosurgery and APC. Some characteristics of the argon discharge are shown and discussed, and thermal effects in biological tissue are described. Subsequently, examples of medical applications are given. PMID:20204117

  4. Overview of the coagulation system

    PubMed Central

    Palta, Sanjeev; Saroa, Richa; Palta, Anshu

    2014-01-01

    Coagulation is a dynamic process and the understanding of the blood coagulation system has evolved over the recent years in anaesthetic practice. Although the traditional classification of the coagulation system into extrinsic and intrinsic pathway is still valid, the newer insights into coagulation provide more authentic description of the same. Normal coagulation pathway represents a balance between the pro coagulant pathway that is responsible for clot formation and the mechanisms that inhibit the same beyond the injury site. Imbalance of the coagulation system may occur in the perioperative period or during critical illness, which may be secondary to numerous factors leading to a tendency of either thrombosis or bleeding. A systematic search of literature on PubMed with MeSH terms ‘coagulation system, haemostasis and anaesthesia revealed twenty eight related clinical trials and review articles in last 10 years. Since the balance of the coagulation system may tilt towards bleeding and thrombosis in many situations, it is mandatory for the clinicians to understand physiologic basis of haemostasis in order to diagnose and manage the abnormalities of the coagulation process and to interpret the diagnostic tests done for the same. PMID:25535411

  5. Systems Biology of Coagulation

    PubMed Central

    Diamond, Scott L.

    2013-01-01

    Accurate computer simulation of blood function can inform drug target selection, patient-specific dosing, clinical trial design, biomedical device design, as well as the scoring of patient-specific disease risk and severity. These large-scale simulations rely on hundreds of independently measured physical parameters and kinetic rate constants. However, the models can be validated against large scale, patient-specific laboratory measurements. By validation with high dimensional data, modelling becomes a powerful tool to predict clinically complex scenarios. Currently, it is possible to accurately predict the clotting rate of plasma or blood in a tube as it is activated with a dose of tissue factor, even as numerous coagulation factors are altered by exogenous attenuation or potentiation. Similarly, the dynamics of platelet activation, as indicated by calcium mobilisation or inside-out signalling, can now be numerically simulated with accuracy in cases where platelets are exposed to combinations of agonists. Multiscale models have emerged to combine platelet function and coagulation kinetics into complete physics-based descriptions of thrombosis under flow. Blood flow controls platelet fluxes, delivery and removal of coagulation factors, adhesive bonding, and von Willebrand factor conformation. The field of Blood Systems Biology has now reached a stage that anticipates the inclusion of contact, complement, and fibrinolytic pathways along with models of neutrophil and endothelial activation. Along with “-omics” data sets, such advanced models seek to predict the multifactorial range of healthy responses and diverse bleeding and clotting scenarios, ultimately to understand and improve patient outcomes. PMID:23809126

  6. Systemic blood coagulation activation in acute coronary syndromes

    PubMed Central

    Undas, Anetta; Szułdrzyński, Konstanty; Brummel-Ziedins, Kathleen E.; Tracz, Wiesława; Zmudka, Krzysztof

    2009-01-01

    We evaluated systemic alterations to the blood coagulation system that occur during a coronary thrombotic event. Peripheral blood coagulation in patients with acute coronary thrombosis was compared with that in people with stable coronary artery disease (CAD). Blood coagulation and platelet activation at the microvascular injury site were assessed using immunochemistry in 28 non-anticoagulated patients with acute myocardial infarction (AMI) versus 28 stable CAD patients matched for age, sex, risk factors, and medications. AMI was associated with increased maximum rates of thrombin-antithrombin complex generation (by 93.8%; P < .001), thrombin B-chain formation (by 57.1%; P < .001), prothrombin consumption (by 27.9%; P = .012), fibrinogen consumption (by 27.0%; P = .02), factor (f) Va light chain generation (by 44.2%; P = .003), and accelerated fVa inactivation (by 76.1%; P < .001), and with enhanced release of platelet-derived soluble CD40 ligand (by 44.4%; P < .001). FVa heavy chain availability was similar in both groups because of enhanced formation and activated protein C (APC)–mediated destruction. The velocity of coagulant reactions in AMI patients showed positive correlations with interleukin-6. Heparin treatment led to dampening of coagulant reactions with profiles similar to those for stable CAD. AMI-induced systemic activation of blood coagulation markedly modifies the pattern of coagulant reactions at the site of injury in peripheral vessels compared with that in stable CAD patients. PMID:18931343

  7. Patterned retinal coagulation with a scanning laser

    NASA Astrophysics Data System (ADS)

    Palanker, Daniel; Jain, ATul; Paulus, Yannis; Andersen, Dan; Blumenkranz, Mark S.

    2007-02-01

    Pan-retinal photocoagulation in patients with diabetic retinopathy typically involves application of more than 1000 laser spots; often resulting in physician fatigue and patient discomfort. We present a semi-automated patterned scanning laser photocoagulator that rapidly applies predetermined patterns of lesions; thus, greatly improving the comfort, efficiency and precision of the treatment. Patterns selected from a graphical user interface are displayed on the retina with an aiming beam, and treatment can be initiated and interrupted by depressing a foot pedal. To deliver a significant number of burns during the eye's fixation time, each pulse should be considerably shorter than conventional 100ms pulse duration. We measured coagulation thresholds and studied clinical and histological outcomes of the application of laser pulses in the range of 1-200ms in pigmented rabbits. Laser power required for producing ophthalmoscopically visible lesions with a laser spot of 132μm decreased from 360 to 37mW with pulse durations increasing from 1 to 100ms. In the range of 10-100ms clinically and histologically equivalent light burns could be produced. The safe therapeutic range of coagulation (ratio of the laser power required to produce a rupture to that for a light burn) decreased with decreasing pulse duration: from 3.8 at 100ms, to 3.0 at 20ms, to 2.5 at 10ms, and to 1.1 at 1ms. Histology demonstrated increased confinement of the thermal damage with shorter pulses, with coagulation zone limited to the photoreceptor layer at pulses shorter than 10ms. Durations of 10-20ms appear to be a good compromise between the speed and safety of retinal coagulation. Rapid application of multiple lesions greatly improves the speed, precision, and reduces pain in retinal photocoagulation.

  8. Systems biology of coagulation.

    PubMed

    Diamond, S L

    2013-06-01

    Accurate computer simulation of blood function can inform drug target selection, patient-specific dosing, clinical trial design, biomedical device design, as well as the scoring of patient-specific disease risk and severity. These large-scale simulations rely on hundreds of independently measured physical parameters and kinetic rate constants. However, the models can be validated against large-scale, patient-specific laboratory measurements. By validation with high-dimensional data, modeling becomes a powerful tool to predict clinically complex scenarios. Currently, it is possible to accurately predict the clotting rate of plasma or blood in a tube as it is activated with a dose of tissue factor, even as numerous coagulation factors are altered by exogenous attenuation or potentiation. Similarly, the dynamics of platelet activation, as indicated by calcium mobilization or inside-out signaling, can now be numerically simulated with accuracy in cases where platelets are exposed to combinations of agonists. Multiscale models have emerged to combine platelet function and coagulation kinetics into complete physics-based descriptions of thrombosis under flow. Blood flow controls platelet fluxes, delivery and removal of coagulation factors, adhesive bonding, and von Willebrand factor conformation. The field of blood systems biology has now reached a stage that anticipates the inclusion of contact, complement, and fibrinolytic pathways along with models of neutrophil and endothelial activation. Along with '-omics' data sets, such advanced models seek to predict the multifactorial range of healthy responses and diverse bleeding and clotting scenarios, ultimately to understand and improve patient outcomes. © 2013 International Society on Thrombosis and Haemostasis.

  9. Arsenic removal by coagulation

    SciTech Connect

    Scott, K.N.; Green, J.F.; Do, H.D.; McLean, S.J.

    1995-04-01

    This study evaluated the removal of naturally occurring arsenic in a full-scale (106-mgd) conventional treatment plant. When the source water was treated with 3--10 mg/L of ferric chloride or 6, 10, or 20 mg/L of alum, arsenic removal was 81--96% (ferric chloride) and 23--71% (alum). Metal concentrations in the sludge produced during this study were below the state`s current hazardous waste levels at all coagulant dosages. No operational difficulties were encountered.

  10. Coagulant modulates the hypocholesterolemic effect of tofu (coagulated soymilk).

    PubMed

    Oboh, Ganiyu

    2007-06-01

    The recent increase in soymilk and tofu (coagulated soymilk) consumption, especially in Western countries, is due to the recognition of the health benefits of soy foods; consumption of soybean would prevent heart diseases. Since the amount and the type of coagulated biomolecules (such as isoflavones) will vary with the type of coagulant, this will inevitably alter their biological activity. This study sought to assess the effect of some coagulants (calcium chloride, alum, and steep water from pap production) commonly used in the production of tofu in Nigeria on the serum cholesterol, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) levels in albino rats fed tofu for 14 days. The results of this study revealed that there was a significant difference (P < .05) in the total phenol [calcium chloride (0.9%), alum (0.8%), and steep water (1.2%)] content of all the tofu produced. Furthermore, feeding albino rats with tofu and water ad libitum for 14 days caused a significant decrease (P < .05) in serum cholesterol and LDL when compared with the control. Conversely, there was a significant increase (P < .05) in serum HDL when compared with the control. However, rats fed steep water-coagulated tofu had the lowest serum levels of cholesterol and LDL, followed by those fed alum- and calcium chloride-coagulated tofu, respectively, while those fed with alum-coagulated tofu had the highest serum HDL level, closely followed by those fed steep water-coagulated tofu. It was therefore concluded that of all the coagulants, steep water appeared to be the most promising coagulant with regard to the production of tofu with a high hypocholesterolemic effect based on the low serum cholesterol and LDL levels and high HDL level.

  11. Coagulation equations with gelation

    SciTech Connect

    Hendriks, E.M.; Ernst, M.H.; Ziff, R.M.

    1983-06-01

    Smoluchowski's equation for rapid coagulation is used to describe the kinetics of gelation, in which the coagulation kernel K/sub i/j models the bonding mechanism. For different classes of kernels we derive criteria for the occurrences of gelation, and obtain critical exponents in the pre- and postgelation stage in terms of the model parameters; we calculate bounds on the time of gelation t/sub c/, and give an exact postgelation solution for the model K/sub i/j = (ij)/sup ..omega../ (..omega..>1/2) and K/sub i/j = ..cap alpha../sup i/+j (..cap alpha..>1). For the model K/sub i/j = i/sup ..omega../+j/sup ..omega../ (..omega..<1, without gelation) initial solutions are given. It is argued that the kernel K/sub i/japprox. (ij)/sup ..omega../ with ..omega..approx. =1-1/d (d is dimensionality) effectively models the sol-gel transformation is polymerizing systems and approximately accounts for the effects of cross-linking and steric hindrance neglected in the classical theory of Flory and Stockmayer (..omega.. = 1). For all ..omega.. the exponents, tau = ..omega..+3/2 and sigma = ..omega..-1/2, ..gamma.. = (3/2-..omega..)/(..omega..-1/2) and ..beta.. = 1, characterize the size distribution, at the slightly below the gel point, under the assumption that scaling is valid.

  12. Blood Coagulation, Inflammation and Malaria

    PubMed Central

    Francischetti, Ivo M. B.; Seydel, Karl B.; Monteiro, Robson Q.

    2010-01-01

    I. ABSTRACT Malaria remains a highly prevalent disease in more than 90 countries and accounts for at least 1 million deaths every year. Plasmodium falciparum infection is often associated with a procoagulant tonus characterized by thrombocytopenia and activation of the coagulation cascade and fibrinolytic system; however, bleeding and hemorrhage are uncommon events, suggesting that a compensated state of blood coagulation activation occurs in malaria. This article i) reviews the literature related to blood coagulation and malaria in a historic perspective, ii) describes basic mechanisms of coagulation, anticoagulation, and fibrinolysis, iii) explains the laboratory changes in acute and compensated disseminated intravascular coagulation (DIC), iv) discusses the implications of tissue factor (TF) expression in the endothelium of P. falciparum-infected patients, and v) emphasizes the pro-coagulant role of parasitized erythrocytes (pRBC) and activated platelets in the pathogenesis of malaria. This article also presents the ‘Tissue Factor Model’ (TFM) for malaria pathogenesis, which places TF as the interface between sequestration, endothelial cell activation, blood coagulation disorder and inflammation often associated with the disease. The relevance of the coagulation-inflammation cycle for the multiorgan dysfunction and coma is discussed in the context of malaria pathogenesis. PMID:18260002

  13. Simulation program for wastewater coagulation.

    PubMed

    Ratnaweera, H; Lei, L; Lindholm, O

    2002-01-01

    The lack of comprehensive simulation models for wastewater coagulation is one of the obstacles to achieving optimal coagulant dosing. Two approaches for developing a model to describe the coagulation process are presented. The comprehensiveness in describing the influent quality with several parameters, rather than with one parameter, is identified to give high efficiency in dosing models based on algorithms constructed using the partial least squares method. The concept was tested on two full-scale wastewater treatment plants, with coagulant savings and effluent quality improvements. Significant differences were observed with the increase of online parameters in the models. The second approach is based on distribution of coagulant for particle and phosphate removal processes and is discussed for inert fractions. The concept is integrated into existing simulation software as a module. The calibration results and dosage predictions are demonstrated.

  14. Platelet coagulation-protein interactions.

    PubMed

    Walsh, Peter N

    2004-08-01

    The biochemical mechanisms by which activated platelets participate in exposing receptors for the assembly of enzyme-cofactor-substrate complexes at all stages of the blood coagulation cascade are reviewed. Information derived from studies conducted during the last 30 years supports the concept that the initiation of blood coagulation is triggered by exposure of tissue factor at injury sites, leading to the generation of minute quantities of thrombin (limited by tissue factor pathway inhibitor), sufficient to activate platelets, factors XI, VIII, and V, and trigger the consolidation pathway (i.e., the sequential activation of factors XI, IX, X, and prothrombin on the activated platelet surface), leading to the generation of sufficient thrombin to convert fibrinogen to fibrin and effect hemostasis. Platelets localize coagulation to the hemostatic thrombus and protect coagulation enzymes from inhibition by both plasma and platelet inhibitors (e.g., protease nexin 2), thus preventing disseminated intravascular coagulation.

  15. Lighting.

    SciTech Connect

    United States. Bonneville Power Administration.

    1992-09-01

    Since lighting accounts for about one-third of the energy used in commercial buildings, there is opportunity to conserve. There are two ways to reduce lighting energy use: modify lighting systems so that they used less electricity and/or reduce the number of hours the lights are used. This booklet presents a number of ways to do both. Topics covered include: reassessing lighting levels, reducing lighting levels, increasing bulb & fixture efficiency, using controls to regulate lighting, and taking advantage of daylight.

  16. Microfluidics and Coagulation Biology

    PubMed Central

    Colace, Thomas V.; Tormoen, Garth W.

    2014-01-01

    The study of blood ex vivo can occur in closed or open systems, with or without flow. Microfluidic devices facilitate measurements of platelet function, coagulation biology, cellular biorheology, adhesion dynamics, pharmacology, and clinical diagnostics. An experimental session can accommodate 100s to 1000s of unique clotting events. Using microfluidics, thrombotic events can be studied on defined surfaces of biopolymers, matrix proteins, and tissue factor under constant flow rate or constant pressure drop conditions. Distinct shear rates can be created on a device with a single perfusion pump. Microfluidic devices facilitated the determination of intraluminal thrombus permeability and the discovery that platelet contractility can be activated by a sudden decrease in flow. Microfluidics are ideal for multicolor imaging of platelets, fibrin, and phosphatidylserine and provide a human blood analog to the mouse injury models. Overall, microfluidic advances offer many opportunities for research, drug testing under relevant hemodynamic conditions, and clinical diagnostics. PMID:23642241

  17. Thermophoretically modified aerosol Brownian coagulation

    NASA Astrophysics Data System (ADS)

    Arias-Zugasti, Manuel; Rosner, Daniel E.

    2011-08-01

    A theory of aerosol coagulation rates resulting from continuum-regime Brownian coagulation in the presence of size-dependent particle thermophoresis is developed and explored here. We are motivated by a wide variety of applications in which particle Brownian coagulation occurs in a nonisothermal gas where differential thermophoretic drift contributes to, but does not dominate, the encounter frequency between suspended spherical particles (e.g., mist droplets) of different sizes. We employ a Smoluchowski-like population-balance to demonstrate the relative roles of Brownian diffusion and thermophoresis in shaping the short and long time (asymptotic or “coagulation-aged”) mist-droplet size distribution (DSD) function. To carry out these combined-mechanism DSD-evolution calculations we developed a rational “coupled” coagulation rate constant (allowing for simultaneous Brownian diffusion and relative thermophoretic drift) rather than simply adding the relevant individual coagulation “kernels.” Dimensionless criteria are provided to facilitate precluding other coagulation mechanisms not considered here (such as simultaneous sedimentation or Marangoni-flow-induced mist-droplet phoresis) and potential complications not included in the present model [as finite-rate coalescence, initial departures from the continuum (Stokes drag-) limit, and even dense (nonideal) vapor effects].

  18. Thermophoretically modified aerosol brownian coagulation.

    PubMed

    Arias-Zugasti, Manuel; Rosner, Daniel E

    2011-08-01

    A theory of aerosol coagulation rates resulting from continuum-regime brownian coagulation in the presence of size-dependent particle thermophoresis is developed and explored here. We are motivated by a wide variety of applications in which particle brownian coagulation occurs in a nonisothermal gas where differential thermophoretic drift contributes to, but does not dominate, the encounter frequency between suspended spherical particles (e.g., mist droplets) of different sizes. We employ a Smoluchowski-like population-balance to demonstrate the relative roles of brownian diffusion and thermophoresis in shaping the short and long time (asymptotic or "coagulation-aged") mist-droplet size distribution (DSD) function. To carry out these combined-mechanism DSD-evolution calculations we developed a rational "coupled" coagulation rate constant (allowing for simultaneous brownian diffusion and relative thermophoretic drift) rather than simply adding the relevant individual coagulation "kernels." Dimensionless criteria are provided to facilitate precluding other coagulation mechanisms not considered here (such as simultaneous sedimentation or Marangoni-flow-induced mist-droplet phoresis) and potential complications not included in the present model [as finite-rate coalescence, initial departures from the continuum (Stokes drag-) limit, and even dense (nonideal) vapor effects].

  19. 21 CFR 864.5400 - Coagulation instrument.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Coagulation instrument. 864.5400 Section 864.5400....5400 Coagulation instrument. (a) Identification. A coagulation instrument is an automated or semiautomated device used to determine the onset of clot formation for in vitro coagulation studies. (b...

  20. 21 CFR 864.5400 - Coagulation instrument.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Coagulation instrument. 864.5400 Section 864.5400....5400 Coagulation instrument. (a) Identification. A coagulation instrument is an automated or semiautomated device used to determine the onset of clot formation for in vitro coagulation studies. (b...

  1. 21 CFR 864.5400 - Coagulation instrument.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Coagulation instrument. 864.5400 Section 864.5400....5400 Coagulation instrument. (a) Identification. A coagulation instrument is an automated or semiautomated device used to determine the onset of clot formation for in vitro coagulation studies. (b...

  2. Disorders of coagulation in pregnancy.

    PubMed

    Katz, D; Beilin, Y

    2015-12-01

    The process of haemostasis is complex and is further complicated in the parturient because of the physiological changes of pregnancy. Understanding these changes and the impact that they have on the safety profile of the anaesthetic options for labour and delivery is crucial to any anaesthetist caring for the parturient. This article analyses current theories on coagulation and reviews the physiological changes to coagulation that occur during pregnancy and the best methods with which to evaluate coagulation. Finally, we examine some of the more common disorders of coagulation that occur during pregnancy, including von Willebrand disease, common factor deficiencies, platelet disorders, the parturient on anticoagulants, and the more rare acute fatty liver of pregnancy, with a focus on their implications for neuraxial anaesthesia. © The Author 2015. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. [Proteins influencing the blood coagulation].

    PubMed

    Alberio, Lorenzo

    2011-11-01

    This review describes some natural proteins, which can be employed, either as factor concentrates derived from human plasma or as recombinant drug, to modulate the coagulation system. I will address some biochemical characteristics and the physiological role of von Willebrand factor, the coagulation factors of the extrinsic and intrinsic pathways, and the physiological anticoagulant protein C. In addition, I will detail the pharmacological compounds, which are available for influencing or substituting the coagulation proteins: desmopressin (DDAVP), single coagulation factor concentrates, prothrombin complex concentrates, and protein C concentrate. In particular, I will address some treatment topics of general medical interest, such as the treatment of massive bleeding, the correction of the coagulopathy induced by vitamin K-antagonists in patients with cerebral haemorrhage, and of the coagulopathy of meningococcemia. Finally, I will describe some properties and practical clinical applications of the recombinant anticoagulans lepirudin and bivalirudin, which are derived from hirudin, the natural anticoagulant of the medical leech.

  4. Whole blood coagulation analyzers.

    PubMed

    1997-08-01

    Whole blood Coagulation analyzers (WBCAs) are widely used point-of-care (POC) testing devices found primarily in cardiothoracic surgical suites and cardia catheterization laboratories. Most of these devices can perform a number of coagulation tests that provide information about a patient's blood clotting status. Clinicians use the results of the WBCA tests, which are available minutes after applying a blood sample, primarily to monitor the effectiveness of heparin therapy--an anticoagulation therapy used during cardiopulmonary bypass (CPB) surgery, angioplasty, hemodialysis, and other clinical procedures. In this study we evaluated five WBCAs from four suppliers. Our testing focused on the applications for which WBCAs are primarily used: Monitoring moderate to high heparin levels, as would be required, for example, during CPB are angioplasty. For this function, WCBAs are typically used to perform an activated clotting time (ACT) test or, as one supplier refers to its test, a heparin management test (HMT). All models included in this study offered an ACT test or an HMT. Monitoring low heparin levels, as would be required, for example,during hemodialysis. For this function, WBCAs would normally be used to perform either a low-range ACT (LACT) test or a whole blood activated partial thromboplastin time (WBAPTT) test. Most of the evaluated units could perform at least one of these tests; one unit did not offer either test and was therefore not rated for this application. We rated and ranked each evaluated model separately for each of these two applications. In addition, we provided a combined rating and ranking that considers the units' appropriateness for performing both application. We based our conclusions on a unit's performance and humans factor design, as determined by our testing, and on its five-year life-cycle cost, as determined by our net present value (NPV) analysis. While we rated all evaluated units acceptable for each appropriate category, we did

  5. Coagulation Parameters in Wilson Disease.

    PubMed

    Schaefer, Mark; Weber, Laura; Gotthardt, Daniel; Seessle, Jessica; Stremmel, Wolfgang; Pfeiffenberger, Jan; Weiss, Karl Heinz

    2015-06-01

    Wilson disease (WD) is an autosomal recessive disorder of copper metabolism. Alterations of copper metabolism have been associated with changes in coagulation factors. The aim of the present study was the analysis of coagulation factors in WD patients. 100 patients attending a tertiary WD outpatient clinic were analyzed in a prospective cross sectional cohort study. Out of peripheral venous blood samples coagulation factors were assessed including: full blood count, INR, partial thromboplastin time (PTT), clotting factors II, V, VII, VIII, IX, X, XI, XII, XIII, von Willebrand factor/-antigen, fibrinogen, antithrombin III, protein S, protein C, activated protein C (APC) resistance. Subgroup analyses of the blood tests were performed for sex, initial clinical presentation, WD treatment and liver function. Subgroup analysis by liver function showed decreased levels of factors II, V, VII and X. Subgroup analysis by gender or clinical course of the disease did not reveal significant coagulation changes. In patients treated with trientine significantly decreased levels of factors II, VII and antithrombin III and increased von Willebrand factor/-antigen levels were detected. Factor VIII levels were significantly reduced in patients receiving zinc. Although significant differences of some coagulation parameters in subgroup analysis were found, no clinically relevant alterations of the coagulation system in WD patients could be detected.

  6. Inherited disorders of blood coagulation.

    PubMed

    Lippi, Giuseppe; Franchini, Massimo; Montagnana, Martina; Favaloro, Emmanuel J

    2012-08-01

    Hemostasis is traditionally defined as a physiological response to blood vessel injury and bleeding, which entails a co-ordinated process involving the blood vessel, platelets, and blood clotting proteins (i.e. coagulation factors). Hemostasis can be divided into primary and secondary components. The former rapidly initiates after endothelial damage and is characterized by vascular contraction, platelet adhesion, and formation of a soft aggregate plug. The latter is initiated following the release of tissue factor and involves a complex sequence of events known as the blood coagulation cascade, encompassing serial steps where each coagulation factor activates another in a chain reaction that culminates in the conversion of fibrinogen to fibrin. Patients carrying abnormalities of the coagulation cascade (i.e. deficiencies of coagulation factors) have an increased bleeding tendency, where the clinical severity is mostly dependent upon the type and the plasma level of the factor affected. These disorders also impose a heavy medical and economic burden on individual patients and society in general. The aim of this article is to provide a general overview on the pathophysiology, clinics, diagnostics, and therapy of inherited disorders of coagulation factors.

  7. Comparison of coagulation performance and floc properties of a novel zirconium-glycine complex coagulant with traditional coagulants.

    PubMed

    Zhang, Zhilin; Wu, Chunde; Wu, Yue; Hu, Caixia

    2014-05-01

    A new inorganic-organic hybrid material zirconium-glycine complex (ZGC) was firstly used as a coagulant in a coagulation process to treat Pearl River raw water. Its coagulation performance was compared with commonly used aluminum (Al) coagulants such as aluminum sulfate (Al2(SO4)3) and polyaluminum chloride (PAC), in terms of water quality parameters and floc properties. ZGC coagulation achieved higher removal of turbidity (93.8%) than other traditional coagulants. Charge neutralization was proven to act as a dominant mechanism during ZGC coagulation. The aggregated flocs with ZGC showed the fastest growth rate and good recovery ability compared with the other coagulants and achieved the largest floc size within 5 min. The ZGC coagulant can decrease the hydraulic retention time and increase removal efficiency.

  8. Coagulation-Flocculation Process in Landfill Leachate Treatment: Focus on Coagulants and Coagulants Aid

    NASA Astrophysics Data System (ADS)

    Kamaruddin, M. A.; Abdullah, M. M. A.; Yusoff, M. S.; Alrozi, R.; Neculai, O.

    2017-06-01

    In physico-chemical treatment, the separation of suspended particles from the liquid phase is usually accomplished by coagulation, flocculation and sedimentation. Coagulation-flocculation processes have been widely used as alternative treatment to remove leachate pollutants such as BOD, COD, TSS, heavy metals, colour, and nitrogen compounds prior to other treatment methods. It is often coupled with treatment methods like biological process, chemical oxidation, adsorption or filtration to achieve desirable effluent quality. In spite of being economical, the dewatering and disposal of the precipitated sludge could be laborious and time-consuming. In this manuscript, brief discussions on coagulant and coagulants aid in landfill leachate treatment is discussed with respect to their mechanism.

  9. Hydrolysis of polyaluminum chloride prior to coagulation: Effects on coagulation behavior and implications for improving coagulation performance.

    PubMed

    Zhang, Zhongguo; Wang, Jun; Liu, Dan; Li, Jiuyi; Wang, Xiaolin; Song, Boyu; Yue, Bing; Zhao, Kehui; Song, Yun

    2017-07-01

    The effects of polyaluminum chloride (PACl) hydrolysis prior to coagulation on both the coagulation zone and coagulation performance of a kaolin suspension were investigated by a novel jar test named the "reversed coagulation test". The tests showed that PACl hydrolysis prior to coagulation decreased the performance of charge neutralization coagulation in the case of short-time slow mixing (10min; G=15sec(-1)) and increased the optimal dosage for charge neutralization and sweep coagulation. Moreover, the hydrolysis time had insignificant effects on the size and zeta potential of PACl precipitates and the residual turbidity of the raw water. However, PACl hydrolysis prior to coagulation and the size of PACl precipitates had a negligible effect on the performance of sweep coagulation. The results imply that, in practice, preparing a PACl solution with deionized water, rather than tap water or the outlet water from a wastewater treatment unit, can significantly save PACl consumption and improve the performance of charge neutralization coagulation, while preparing the PACl solution with tap or outlet water would not affect the performance of sweep coagulation. In addition, the optimal rapid mixing intensity appears to be determined by a balance between the degree of coagulant hydrolysis before contacting the primary particles and the average size of flocs in the rapid mixing period. These results provide new insights into the role of PACl hydrolysis and will be useful for improving coagulation efficiency. Copyright © 2016. Published by Elsevier B.V.

  10. [Coagulation disorders in the intensive care station].

    PubMed

    Hart, C; Spannagl, M

    2014-05-01

    Coagulation disorders are frequently encountered in the intensive care unit (ICU) and are challenging due to a variety of potential etiologies. Critically ill patients with coagulation abnormalities may present with an increased risk of bleeding, show coagulation activation resulting in thromboembolism, or have no specific symptoms. Hemostatic abnormalities observed in ICU patients range from isolated thrombocytopenia or prolonged global clotting tests to complex and life-threatening coagulation defects. Successful management of coagulation disorders requires prompt and accurate identification of the underlying cause. This review describes the most frequently occurring diagnoses found in intensive care patients with thrombocytopenia and coagulation test abnormalities and summarizes appropriate diagnostic interventions and current approaches to differential diagnosis.

  11. Ultrasonic measurement of milk coagulation time

    NASA Astrophysics Data System (ADS)

    Bakkali, F.; Moudden, A.; Faiz, B.; Amghar, A.; Maze, G.; Montero de Espinosa, F.; Akhnak, M.

    2001-12-01

    Using a pulse reflection technique an ultrasonic system has been developed to monitor in situ the coagulation process of rennetted milk. The velocity and attenuation of ultrasonic waves through coagulating milk were continuously monitored. The observed changes in ultrasonic velocity during coagulation were used to predict the coagulation time. The coagulation time is indicative of the transition from the enzymatic phase to the physicochemical phase. The determination of coagulation time has a decisive role in determining the qualities of the end product in cheesemaking.

  12. Advances of Coagulation Factor XIII

    PubMed Central

    Shi, Da-Yu; Wang, Shu-Jie

    2017-01-01

    Objective: To provide a comprehensive literature review on roles of coagulation factor XIII (FXIII) in coagulation, wound healing, neoplasm, bone metabolism, and pregnancy. Data Sources: All articles in PubMed with key words Coagulation factor XIII, wound, leukemia, tumor, bone, and pregnancy with published date from 2001 to 2016 were included in the study. Frequently cited publications before 2000 were also included. Study Selection: We reviewed the role of FXIII in biologic processes as documented in clinical, animal, and in vitro studies. Results: FXIII, a member of the transglutaminase (TG) family, plays key roles in various biological processes. Besides its well-known function in coagulation, the cross-linking of small molecules catalyzed by FXIII has been found in studies to help promote wound healing, improve bone metabolism, and prevent miscarriages. The study has also shown that FXIII concentration level differs in the blood of patients with leukemia and solid tumors and offers promises as a diagnostic indicator. Conclusions: FXIII has many more biologic functions besides being known as coagulation factor. The TG activity of FXIII contributes to several processes, including wound healing, bone extracellular matrix stabilization, and the interaction between embryo and decidua of uterus. Further research is needed to elucidate the link between FXIII and leukemia and solid tumors. PMID:28091415

  13. Interspecies differences in coagulation profile.

    PubMed

    Siller-Matula, Jolanta M; Plasenzotti, Roberto; Spiel, Alexander; Quehenberger, Peter; Jilma, Bernd

    2008-09-01

    Many animals are used in research on blood coagulation and fibrinolysis, but the relevance of animal models to human health is often questioned because of differences between species. The objective was to find an appropriate animal species, which mimics the coagulation profile in humans most adequately. Species differences in the coagulation profile with and without thrombin stimulation in vitro were assessed in whole blood by Rotation Thromboelastometry (ROTEM). Endogenous thrombin generation was measured in platelet-poor plasma. Measurements were performed in blood from five different species: humans, rats, pigs, sheep and rabbits. In humans and sheep, the clotting time (ROTEM) was in the same range with or without thrombin stimulation and a 100-fold lower dose of thrombin (0.002 IU) was required to cause a shortening in the clotting time as compared to rats, pigs and rabbits (0.2 IU) (p<0.05). Similarly, the endogenous thrombin potential (ETP) was in the same range in humans and sheep. The maximum clot firmness with or without thrombin stimulation was similar in rabbits and humans. The maximum lysis with or without thrombin stimulation was similar in humans and pigs. Significant species differences exist in the coagulation profile with or without thrombin stimulation. Most importantly, sheep had a clotting time most similar to humans and could thus be a suitable species for translational coagulation studies. Moreover, our findings confirm the potential usefulness of pigs as an experimental species to study fibrinolytic pathway and support the usefulness of rabbits as a species for examining platelets.

  14. Light

    NASA Astrophysics Data System (ADS)

    Vernon, C. G.

    2016-09-01

    Preface; 1. Historical; 2. Waves and wave-motion; 3. The behaviour of ripples; 4. The behaviour of light; 5. Refraction through glass blocks and prisms; 6. The imprinting of curvatures; 7. Simple mathematical treatment; 8. More advanced mathematical treatment; 9. The velocity of light; 10. The spectrum and colour; 11. Geometrical optics; 12. The eye and optical instruments; 13. Sources of light; 14. Interference, diffraction and polarisation; 15. Suggestions for class experiments; Index.

  15. Coagulation assays and anticoagulant monitoring.

    PubMed

    Funk, Dorothy M Adcock

    2012-01-01

    Anticoagulant therapy, including conventional agents and a variety of new oral, fast-acting drugs, is prescribed for millions of patients annually. Each anticoagulant varies in its effect on routine and specialty coagulation assays and each drug may require distinct laboratory assay(s) to measure drug concentration or activity. This review provides an overview of the assorted assays that can measure anticoagulant drug concentration or activity and includes key assay interferences. The effect of these conventional and new anticoagulant agents on specialty coagulation assays used to evaluate for bleeding or clotting disorders, and whether this impact is physiological or factitious, is included. Also provided is a short review of superwarfarin poisoning and features distinguishing this from warfarin overdose. Knowledge of clinically significant pearls and pitfalls pertinent to coagulation assays in relation to anticoagulant therapy are important to optimize patient care.

  16. Enhanced coagulation for arsenic removal

    SciTech Connect

    Cheng, R.C.; Liang, S.; Wang, H.C.; Beuhler, M.D. )

    1994-09-01

    The possible use of enhanced coagulation for arsenic removal was examined at the facilities of a California utility in 1992 and 1993. The tests were conducted at bench, pilot, and demonstration scales, with two source waters. Alum and ferric chloride, with cationic polymer, were investigated at various influence arsenic concentrations. The investigators concluded that for the source waters tested, enhanced coagulation could be effective for arsenic removal and that less ferric chloride than alum, on a weight basis, is needed to achieve the same removal.

  17. Depinning as a coagulation process

    NASA Astrophysics Data System (ADS)

    İşeri, M.; Kaspar, D.; Mungan, M.

    2016-08-01

    We consider a one-dimensional model that describes the depinning of an elastic string of particles in a strongly pinning, phase-disordered periodic environment under a slowly increasing force. The evolution towards depinning occurs by the triggering of avalanches in regions of activity which are at first isolated, but later grow and merge. For large system sizes the dynamically critical behavior is dominated by the coagulation of these active regions. Our analysis and numerical simulations show that the evolution of the sizes of active regions is well described by a Smoluchowski coagulation equation, allowing us to predict correlation lengths and avalanche sizes in terms of certain moments of the size distribution.

  18. [Coagulation behavior of Al13 species].

    PubMed

    Hu, Cheng-zhi; Liu, Hui-juan; Qu, Jiu-hui

    2006-12-01

    Coagulation behavior of Al13 species was examined in synthetic water with high alkalinity and high humic acid concentration from viewpoint of the transformation of Al hydrolysis products during the coagulation process. The results indicated that coagulation efficiency of Al coagulants positively correlated with the content of Al13 in the coagulation process. Aluminum chloride (AlCl3) was more effective than polyaluminum chloride (PACI) in removing turbidity and dissolved organic matter in the synthetic water because AlCl3 could not only generate Al13 species but also function as pH control agent in the coagulation process. During coagulation process pH control can improve coagulation process through regulating Al speciation, and AlCl3 benefited most from pH control.

  19. Controlling coagulation dysregulation in xenotransplantation.

    PubMed

    Cowan, Peter J; Robson, Simon C; d'Apice, Anthony J F

    2011-04-01

    Deletion of the α1,3-galactosyltransferase (GalT) gene in pigs has removed a major xenoantigen but has not eliminated the problem of dysregulated coagulation and vascular injury. Rejecting GalT knockout organ xenografts almost invariably show evidence of thrombosis and platelet sequestration, and primate recipients frequently develop consumptive coagulopathy. This review examines recent findings that illuminate potential mechanisms of this current barrier to successful xenotransplantation. The coagulation response to xenotransplantation differs depending on the type of organ and quite likely the distinct vasculatures. Renal xenografts appear more likely to initiate consumptive coagulopathy than cardiac xenografts, possibly reflecting differential transcriptional responses. Liver xenografts induce rapid and profound thrombocytopenia resulting in recipient death within days due to bleeding; ex-vivo data suggest that liver endothelial cells and hepatocytes are responsible for platelet consumption by a coagulation-independent process.It has been proposed that expression of recipient tissue factor on platelets and monocytes is an important trigger of consumptive coagulopathy. Finally, pigs transgenic for human anticoagulants and antithrombotics are slowly but surely coming on line, but have not yet been rigorously tested to date. Successful control of coagulation dysregulation in xenotransplantation may require different combinatorial pharmacological and genetic strategies for different organs.

  20. Microwave coagulation for liver metastases.

    PubMed

    Bala, Malgorzata M; Riemsma, Robert P; Wolff, Robert; Kleijnen, Jos

    2013-10-13

    Primary liver cancer and liver metastases from colorectal carcinoma are the two most common malignant tumours to affect the liver. The liver is second only to the lymph nodes as the most common site for metastatic disease. More than half of patients with metastatic liver disease will die from metastatic complications. Microwave coagulation involves placing an electrode into a lesion under ultrasound or computed tomography guidance. The microwave coagulator generates and transmits microwave energy to the electrode. Coagulative necrosis causes cellular death and destroys tissue in the treatment area, resulting in reduction of tumour size. To study the beneficial and harmful effects of microwave coagulation compared with no intervention, other ablation methods, or systemic treatments in patients with liver metastases. We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, The Cochrane Central Register of Controlled Trials (CENTRAL) in The Cochrane Library, MEDLINE, EMBASE, Science Citation Index Expanded, LILACS, and CINAHL up to December 2012. We included all randomised clinical trials assessing beneficial and harmful effects of microwave coagulation and its comparators, irrespective of the location of the primary tumour. We extracted relevant information on participant characteristics, interventions, and study outcomes and data on outcome measures for our review, as well as information on design and methodology of the studies. Bias risk assessment of trials, determination of whether they fulfilled the inclusion criteria, and data extraction from retrieved for final evaluation trials were done by one review author and were checked by a second review author. One randomised clinical trial fulfilled the inclusion criteria of the review. Forty participants with multiple liver metastases of colorectal cancer and no evidence of extrahepatic disease were randomly assigned. Thirty of these participants (14 females and 16 males) were included in the

  1. International reference standards in coagulation.

    PubMed

    Raut, Sanj; Hubbard, Anthony R

    2010-07-01

    Measurement of coagulation factor activity using absolute physico-chemical techniques is not possible and estimation therefore relies on comparative bioassay relative to a reference standard with a known or assigned potency. However the inherent variability of locally prepared and calibrated reference standards can give rise to poor agreement between laboratories and methods. Harmonisation of measurement between laboratories at the international level relies on the availability of a common source of calibration for local reference standards and this is provided by the World Health Organization (WHO) International Standards which define the International Unit for the analyte. This article describes the principles, practices and problems of biological standardisation and the development and use of reference standards for assays of coagulation factors, with particular emphasis on WHO International Standards for both concentrates and plasma. Crown Copyright 2010. Published by Elsevier Ltd. All rights reserved.

  2. [Mechanism of natural organic matter removal by potassium permanganate composite enhanced coagulation].

    PubMed

    Zhang, Yong-Ji; Zhou, Ling-Ling; Li, Wei-Ying; Li, Xing; Li, De-Qiang; Li, Gui-Bai

    2009-03-15

    Streaming current technique, fluctuation of transmitted light technique, molecular weight distribution and XAD resin adsorption technique were used to study the mechanism of natural organic matter removal by potassium permanganate composite (PPC) enhanced coagulation. Results showed that natural organic matter removal efficiency increased 13% by 0.75 mg/L potassium permanganate composite enhanced coagulation compared with that of alum coagulation alone. Streaming current indicated that potassium permanganate composite decreased the organic matter stability by reducing the surface negative charge, and the SC value increased from 55.2 to 61.4, 69.6 and 87.0 by addition of 0.50, 0.75 and 1.0 mg/L PPC. Coagulation index R indicated both nascent manganese dioxide and subsidiaries played an important role in potassium permanganate composite enhanced coagulation process. Potassium permanganate composite enhanced coagulation increased the removal efficiency of lower molecular weight and hydrophilic organic matter compared with alum coagulation, and hydrophilic organic matter can be reduced from 1.9 mg/L to 1.32 mg/L by the addition of 0.75 mg/L potassium permanganate composite.

  3. The influence of riboflavin photochemistry on plasma coagulation factors

    PubMed Central

    Larrea, Luis; Calabuig, María; Roldán, Vanesa; Rivera, José; Tsai, Han-Mou; Vicente, Vicente; Roig, Roberto

    2011-01-01

    Studies with riboflavin in the 1960s showed that it could be effective at inactivating pathogens when exposed to light. The principal mode of action is through electron transfer reactions, most importantly in nucleic acids. This suggested that it could act as a photosensitizer useful in the inactivation of pathogens found in blood products. Objective To study the influence of photo-inactivation with riboflavin on the coagulation factors of plasma. Methods The photo-inactivation procedure of riboflavin plus light was applied. Fifty isogroup pools of two plasmas were made from 100 U of plasma that were derived from whole blood products that had previously been held overnight. Pools were split into two bags. One of them was photo-inactivated, and post inactivation samples were obtained. The second bag was not photo-inactivated and samples were taken. Total protein, fibrinogen, FII, FV, FVII, FVIII, FIX, FX, FXI, FXIII, antithrombin III, PC, PS, α-2 antiplasmin and vWF:Ag, the multimeric structure of vWF and ADAMTS-13 were analyzed. Results In plasma, the proteins most sensitive to photo-inactivation were fibrinogen, FXI, FVIII, FV, and FIX (33%, 32%, 30%, 18% and 18% loss, respectively). Coagulation inhibitors, PS, antithrombin III and PC showed little decrease (all 2%). Retention of vWF and ADAMTS-13 were 99% and 88%, respectively. Conclusions As with other pathogen reduction procedures for plasma products, treatment with riboflavin and UV light resulted in reduction in the activity levels of several pro-coagulant factors. Coagulation inhibitors are well preserved. PMID:19782644

  4. The reciprocal relationship between inflammation and coagulation.

    PubMed

    O'Brien, Mauria

    2012-05-01

    Inflammation and coagulation constitute two host defense systems with complementary roles in eliminating invading pathogens, limiting tissue damage, and restoring homeostasis. Extensive cross talk exists between these 2 systems, whereby inflammation leads to activation of coagulation, and coagulation considerably affects inflammatory activity. Infection leads to the production of proinflammatory cytokines that, in turn, stimulate the production of tissue factor. Activation of the coagulation system and ensuing thrombin generation are dependent on the expression of tissue factor. Conversely, activated coagulation proteases may affect specific receptors on inflammatory cells and endothelial cells and thereby modulate the inflammatory response. Activation of coagulation with the simultaneous down-regulation of endothelial-bound anticoagulant mechanisms and endogenous fibrinolysis characterizes the pathophysiology of sepsis. The mechanisms by which these highly complex and codependent defense strategies are linked together both in health and disease is the focus of this review.

  5. [Monitoring of blood coagulation in perioperative care].

    PubMed

    Ishii, Hisanari

    2012-01-01

    Coagulation disorders often occur perioperatively and monitoring of blood coagulation should be fast and adequate to treat these disorders to protect patients from massive bleeding. Control of hemostasis is one of the main issues in major surgeries. Coagulation test results from a central laboratory may delay making such a perioperative decision. Recently, point-of-care monitoring (POCM), which is able to examine coagulation disorder in an operation theater with short waiting time, has become important. Both prothrombin time (PT) and activated clotting time (ACT) are very useful and popular, but also criticized because they can be monitored only until fibrin formation. On the other hand, viscoelastic monitorings of whole blood, are able to estimate fibrin formation, clot fixation, platelet function and fibrinolysis. In this review article, among variable perioperative POCMs of blood coagulation, three thromboelastographic monitorings, such as TEG ROTEM, and Sonoclot as well as PT and ACT, are described along with their utilities and limits to examine perioperative coagulation.

  6. [Effects of UV Radiation on the Physicochemical Properties and Coagulation Properties of Humic Acid Solution].

    PubMed

    Wang, Wen-dong; Zhang, Ke; Fan, Qing-hai; Zheng, Dan

    2016-03-15

    To investigate the mechanism of UV light in promoting the removal of humic acid ( HA) by coagulation, the variations of the physical and chemical properties of the HA solution before and after UV light radiation were investigated. The effects of the changes in water quality conditions on the removal performance of HA in coagulation were also observed. Experimental results showed that except zeta potential, pH, chromaticity and viscosity of the HA solution exhibited varying degrees of decline after UV radiation. Further study showed that the impact of changes in viscosity of the solution on humic acid coagulation performance was relatively small. Under acidic conditions, the coagulation performance of HA significantly increased. The increase of zeta potential led to easy gathering of colloidal particles and improved the coagulation performance. Furthermore, except for HA with relative molecular mass of between (10-30) x 10³ and less than 10³, there was little variation in the proportion of low molecular weight HA, which may be an important reason that the coagulation performance of the humic acid solution increased after UV radiation.

  7. Two-wavelength approach for control of coagulation depth during laser tissue soldering

    NASA Astrophysics Data System (ADS)

    Wehner, Martin; Aden, Mirko; Toedter, Nina; Rosenkranz, Beate

    2015-03-01

    In laser tissue soldering (LTS) protein solutions are used for closing of incisions or fixation of wound dressings. During coagulation and thermal denaturation of the protein solutions their morphology changes significantly such that light is strongly scattered. When scattering becomes major component extinction increases and the optical penetration depth shrinks which could lead to unsufficient coagulation and bonding. For adaption of extinction during coagulation we are investigating a two-wavelength approach. A strongly absorbed laser wavelength (1540 nm) and weakly absorbed wavelength (980 nm) can be applied simultaneously. Simulation of beam propagation is performed in natural and coagulated state of the solder. The model describes a three-layer system consisting of membrane, solder and phantom. The optical properties are determined by spectrometric measurements both in natural and coagulated state. The absorption coefficient μa, scattering coefficient μs and anisotropy factor γ are determined by numerical analysis from the spectrometric data. Beam propagation is simulated for 980 nm and 1540 nm radiation with ZEMAX® software based on the Monte Carlo method. For both wavelengths the beginning of the process with a clear solder layer, and the final state characterized by a coagulated solder layer are examined. The optical penetration depth depends mainly on the optical properties of the solder, which change in the course of coagulation process. The coagulation depth can be varied between 1.5 mm to 3.5 mm by changing the proportion of both laser sources. This leads to concepts for minimizing heat input while maintaining a constant coagulation depth.

  8. Simulation of coagulation, flocculation, and sedimentation.

    PubMed

    Smoczynski, L; Bukowski, Z; Wardzynska, R; Zaleska-Chrost, B; Dluzynska, K

    2009-04-01

    The computer program ZB2 was used to study simulated coagulation, flocculation, and sedimentation. The effect of the initial velocity of soil particles on the values of reaction-rate constants was investigated. In this respect, the results obtained with the program ZB2 corresponded to the theory and realities of coagulation carried out under practical conditions. The effect of coagulant excess/deficiency on the formation of the first floc and on the rate of coagulation of 50% of a soil was also estimated. An increase in simulated coagulant excess caused a decrease in the simulated rate of soil coagulation. In this respect, the results obtained with the program ZB2 did not correspond to the realities of coagulation carried out under practical conditions. An attempt was made to explain this inconsistency referring to the coagulation-flocculation theory. The simulation program ZB2 may provide a basis for developing "local" programs simulating coagulation-flocculation, which can be successfully applied at wastewater treatment plants.

  9. Change of coagulation parameters after double plateletpheresis.

    PubMed

    Yilmaz, Mustafa; Dikmen, Tamer; Sonmez, Mehmet; Akdogan, Elif; Durmus, Ahmet; Omay, Serdar Bedii; Ovali, Ercument

    2007-10-01

    In the previous studies, some authors reported that automated apheresis leads to a hypercoagulable state. We tried to find out changes in coagulation parameters after double plateletpheresis in this study. Forty-five donors were recruited to the study, and coagulation parameters were assessed before and after double plateletpheresis. After double plateletpheresis, fibrinogen, factor V, factor VIII and factor IX were decreased compared with the values before apheresis. Although serum levels of this coagulation parameters are decreasing, they are still in the normal limits. Therefore, we suggest that double plateletpheresis is a safe procedure for healthy volunteers taking into account these coagulation parameters.

  10. Coagulation in patients with severe sepsis.

    PubMed

    Levi, Marcel; Poll, Tom van der

    2015-02-01

    In the majority of patients with severe sepsis, systemic activation of coagulation is present. Increasing evidence points to an extensive cross-talk between coagulation and inflammation that may play an important role in the pathogenesis of sepsis. Inflammation not only leads to activation of coagulation, but coagulation also considerably affects inflammatory activity. Molecular pathways that contribute to inflammation-induced activation of coagulation have been precisely identified. Proinflammatory cytokines and other mediators are capable of activating the coagulation system and downregulating important physiological anticoagulant pathways. Activation of the coagulation system and ensuing thrombin generation is dependent on expression of tissue factor on activated mononuclear cells and endothelial cells, and is insufficiently counteracted by TFPI. Simultaneously, endothelial-bound anticoagulant mechanism, in particular the protein C system, is shutoff by proinflammatory cytokines. In addition, fibrin removal is severely inhibited, because of inactivation of the fibrinolytic system, caused by an upregulation of its main inhibitor, plasminogen activator inhibitor type 1 (PAI-1). Increased fibrin formation and impaired removal lead to (micro)vascular thrombosis, which may result in tissue ischemia and subsequent organ damage. The cornerstone of the management of coagulation in sepsis is the specific and vigorous treatment of the underlying disorder. Strategies aimed at the inhibition of coagulation activation may theoretically be justified and have been found beneficial in experimental and initial clinical studies. Heparin may be an effective anticoagulant approach and alternative strategies comprise restoration of physiological anticoagulant pathways.

  11. Lighting

    SciTech Connect

    Audin, L.

    1994-12-31

    EPAct covers a vast territory beyond lighting and, like all legislation, also contains numerous {open_quotes}favors,{close_quotes} compromises, and even some sleight-of-hand. Tucked away under Title XIX, for example, is an increase from 20% to 28% tax on gambling winnings, effective January 1, 1993 - apparently as a way to help pay for new spending listed elsewhere in the bill. Overall, it is a landmark piece of legislation, about a decade overdue. It remains to be seen how the Federal Government will enforce upgrading of state (or even their own) energy codes. There is no mention of funding for {open_quotes}energy police{close_quotes} in EPAct. Merely creating such a national standard, however, provides a target for those who sincerely wish to create an energy-efficient future.

  12. Genetic engineering and coagulation factors.

    PubMed

    Fass, D N; Toole, J J

    1985-06-01

    It is unfortunate that we cannot report, in the area of coagulation, advances that have been seen in related fields such as thrombolytic therapy. The reported progress (Gold et al, 1984; Van de Werf et al, 1984) with human recombinant tissue plasminogen activator (Pennica et al, 1983) augers well for the application of recombinant technology to the problems faced by patients with coagulation defects. While plasminogen activator is being assessed in an acute therapeutic setting, its use signals a beginning of the application of the technology to abnormalities of the haemostatic mechanism. Chronic administration of coagulation factors for prophylaxis and replacement therapy would appear to be just one more step down the pathway illuminated by the biochemists, microbiologists and cell biologists who have preceded the clinicians in this promising area. There is no record of the use of genetically engineered materials in the treatment of coagulation defects, primarily because the body of knowledge and refined techniques have only recently been acquired. For this reason we have had to project developments in other areas onto the problems that exist for the haemostatically compromised patient. In describing the potential usefulness of these technologies, it is difficult to ascertain where the logical projection, from a fully investigated model system, diverges from flights of imaginative fancy. Cloning projects considered overly ambitious and grandiose at the beginning of this decade are already accomplished feats. The feasibility of gene therapy in the mammalian system has been demonstrated, and trade publications now discuss governmental approval for investigative use of this procedure in 1985. Panels of physicians, scientists and even politicians now seriously contemplate and promulgate views and regulations pertaining to the efficacy and ethics of the use of genetic engineering in the treatment of human disease. The haemophilias will certainly be among the first

  13. Increased coagulation in childhood obesity.

    PubMed

    Bilge, Yildiz Dallar; Alioglu, Bulent; Simşek, Enver; Tapci, Ayse Esra; Ozen, Cınar

    2012-11-01

    This study aims to explore the relation between childhood obesity and procoagulant and anticoagulant systems. Fifty-one obese children and 32 normal-weighted children with similar age and gender distribution and between ages of 5 and 16 years were recruited to the study. Antropometric measures of all subjects, existence of any accompanying disease, and medication histories had been recorded. Full blood count, procoagulant, and anticoagulant coagulation tests were run for all subjects. When hematologic variables of obese children were compared with those of healthy controls, it was found that average erythrocyte hemoglobin concentration, erythrocyte distribution width, and platelet count of obese children are significantly higher than healthy control group. It was also found that fibrinogen, thrombin time, factor (F) VIII, FIX, FX, and von Willebrand factor levels of obese children are higher than healthy control group. By contrast, antithrombin levels of obese children are found to be lower. In our study, we found that there is a procoagulant increase in the coagulation system activity of obese children compared to non-obese healthy children, whereas there is a significant decrease in anticoagulant system. These changes occurred in obese patients, especially higher levels of plasma procoagulant factors such as fibrinogen, FVIII, FIX, and von Willebrand factor, lead us to think that there is an activity in these patients at endothelial level. Further studies are needed on endothelial activity of obese children.

  14. [Blood coagulation disorders in oncological patients].

    PubMed

    von Depka Prondzinski, M

    2005-01-01

    Patients with malignancies often experience acute disorders of coagulation. They may manifest as thromboembolism, disseminated intravascular coagulation or a tendency to bleed. Either disorder carries a high rate of complications and a difficult task in diagnosing and treating them. Some complications typical for patients with malignancies are discussed. Among these are tumor associated thrombophilia, acquired von Willebrand's disease, and thrombocytopenia.

  15. Virus inactivation in aluminum and polyaluminum coagulation.

    PubMed

    Matsui, Yoshihiko; Matsushita, Taku; Sakuma, Satoru; Gojo, Takahito; Mamiya, Teppei; Suzuoki, Hiroshi; Inoue, Takanobu

    2003-11-15

    Inorganic aluminum salts, such as aluminum sulfate, are coagulants that cause small particles, such as bacteria and viruses as well as inorganic particles, to destabilize and combine into larger aggregates. In this investigation, batch coagulation treatments of water samples spiked with Qbeta, MS2, T4, and P1 viruses were conducted with four different aluminum coagulants. The total infectious virus concentration in the suspension of floc particles that eventually formed by dosing with coagulant was measured after the floc particles were dissolved by raising the pH with an alkaline beef extract solution. The virus concentrations were extremely reduced after the water samples were dosed with aluminum coagulants. Viruses mixed with and adsorbed onto preformed aluminum hydroxide floc were, however, completely recovered after the floc dissolution. These results indicated that the aluminum coagulation process inactivates viruses. Virucidal activity was most prominent with the prehydrolyzed aluminum salt coagulant, polyaluminum chloride (PACl). Virucidal activity was lower in river water than in ultrapure water--natural organic matter in the river water depressed the virucidal activity. Mechanisms and kinetics of the virus inactivation were discussed. Our results suggest that intermediate polymers formed during hydrolysis of the aluminum coagulants sorbed strongly to viruses, either rendering them inactive or preventing infectivity.

  16. Immunoassays for diagnosis of coagulation disorders.

    PubMed

    Kappel, A; Ehm, M

    2010-11-01

    Immunoassays play a pivotal role in the clinical laboratory. In the coagulation section of the laboratory, they are used as an aid for diagnosis of deep vein thrombosis or pulmonary embolism, thrombophilia screening, or detection of coagulation factor deficiencies, respectively. Enzyme-linked immunosorbent assay (ELISA) and latex agglutination immunoassay technologies are currently most widely used, while Luminescent Oxygen Channeling Immunoassay (LOCI®) and other chemiluminescence-based immunoassays are emerging technologies for the coagulation laboratory. However, not all immunoassay technologies employed are compatible with the workflow requirements of the coagulation laboratory, and, not all technologies are suitable for detection or quantification of every marker. This review focuses on technical and performance aspects of those immunoassay technologies that are most widely used in the coagulation laboratory, and provides a description of markers that are typically tested by immunoassays.

  17. Textile wastewater purification through natural coagulants

    NASA Astrophysics Data System (ADS)

    Beltrán-Heredia, J.; Sánchez-Martín, J.; Rodríguez-Sánchez, M. T.

    2011-09-01

    A new coagulant obtained through polymerization of Acacia mearnsii de Wild tannin extract has been characterized in the removal of two dangerous dye pollutants: Alizarin Violet 3R and Palatine Fast Black WAN. This coagulant is lab-synthesized according to the etherification of tannins with glycidyltrimethylammonium chloride and formaldehyde and its performance in dye removal in terms of efficiency was high. Reasonably low coagulant dosages (ca. 50 mg L-1) reaches high capacity levels (around 0.8 for Alizarin Violet 3R and 1.6 for Palatine Fast Black WAN mg dye mg-1 of coagulant) and pH and temperature are not extremely affecting variables. The systems coagulant dyes were successfully modeled by applying the Langmuir hypothesis. q max and b parameters were obtained with an adjusted correlation factor ( r 2) above 0.8.

  18. Interstitial laser coagulation therapy for benign prostatic hyperplasia

    NASA Astrophysics Data System (ADS)

    McNicholas, Thomas A.; Alsudani, Mohammed

    1996-05-01

    Alternatives to the side-firing laser method include controlled destruction of prostatic adenoma by an atraumatic saline cooled laser fiber introduced endoscopically into the prostate under visual and transrectal ultrasound (TRUS) control. Laser light produces intense heating and interstitial laser coagulation (ILC) occurs with characteristic TRUS changes which are used to control the volume of tissue destruction. The prostatic urethral lining is preserved which may reduce laser side effects). Thirty-six men with symptomatic BPH were treated by ILC between April 1994 and September 1995. All were discharged home on the first post-operative day and reviewed periodically to 12 months post-treatment with measurement of IPSS, flow rate (FR), residual volume, complications, potency and TRUS. Seventeen men (47%) voided immediately, 15 (42%) performed intermittent self-catheterization (ISC) for 3.5 days (2 - 5). Four men (11%) required catheterization for 1/52. Thirty-five men tolerated the treatment well, requiring only mild oral analgesia. One man developed dysuria and required early transurethral resection revealing a large volume of coagulative necrosis. Improvement in symptoms and flow rate developed from 1 - 30 days later. There were no significant complications. Hyperechoic and cystic zones developed at the ILC site which persisted to 12 months. This clinical study indicates the feasibility and safety of intense heating by ILC with visible and ultrasound control to coagulate the adenoma while preserving the urethra. Changes are easily seen on TRUS, symptomatic improvement is good and there have been minimal urethral symptoms or complications.

  19. Dust grain coagulation modelling : From discrete to continuous

    NASA Astrophysics Data System (ADS)

    Paruta, P.; Hendrix, T.; Keppens, R.

    2016-07-01

    In molecular clouds, stars are formed from a mixture of gas, plasma and dust particles. The dynamics of this formation is still actively investigated and a study of dust coagulation can help to shed light on this process. Starting from a pre-existing discrete coagulation model, this work aims to mathematically explore its properties and its suitability for numerical validation. The crucial step is in our reinterpretation from its original discrete to a well-defined continuous form, which results in the well-known Smoluchowski coagulation equation. This opens up the possibility of exploiting previous results in order to prove the existence and uniqueness of a mass conserving solution for the evolution of dust grain size distribution. Ultimately, to allow for a more flexible numerical implementation, the problem is rewritten as a non-linear hyperbolic integro-differential equation and solved using a finite volume discretisation. It is demonstrated that there is an exact numerical agreement with the initial discrete model, with improved accuracy. This is of interest for further work on dynamically coupled gas with dust simulations.

  20. Novel ferromagnetic nanoparticle composited PACls and their coagulation characteristics.

    PubMed

    Zhang, M; Xiao, F; Xu, X Z; Wang, D S

    2012-01-01

    Effects of magnetic nanoparticles on inorganic coagulants and their coagulation performances were studied in the present work. The Fe(3)O(4)-SiO(2) core-shell particle (FSCSP) and superfine iron (SI), were compounded with polyaluminium chloride of basicity 2.0 (PACl2.0), providing magnetic PACl2.0s (MPACl2.0s). The physiochemical properties of ferromagnetic nanoparticles were investigated using transmission electron microscopy (TEM), the BET method and a zeta potentiometric analyzer. The Al species distributions of the MPACl2.0s and PACl2.0 were examined by liquid (27)Al NMR. Jar tests were employed to evaluate the coagulation performances. Floc properties were assessed by use of the electromotive microscope (EM) and small angle laser light scattering (SALLS). The results showed that modified layers of nanoparticles mitigated agglomeration. FSCSP had a larger specific area and pore volume than SI. The addition of ferromagnetic nanoparticles obviously increased the content of Al(un). MPACl2.0s performed better than PACl2.0 in turbidity removal and DOC removal when dosed less than 0.06 mmol/L as Al. Generally, PACl2.0 + FSCSP (50 mg/L) performed best. Large, loose and weak flocs were produced by MPACl2.0s, which were preferred for the magnetic powder recycling. A plausible structure, Al species-nanoparticles cluster, contributing to the unique properties of MPACl2.0 flocs, was proposed.

  1. [Coagulation profiles during cardiac surgery].

    PubMed

    Bitkova, E E; Zvereva, N Iu; Khvatov, V B; Chumakov, M V; Timerbaev, V Kh; Dublev, A V; Redkoborodyĭ, A V

    2014-01-01

    To evaluate patients' hemostasis after cardiac surgery using thromboelastometric and impedance aggregometry. 66 patients were examined intraoperatively. Comparison group included 45 blood donors. Hemostasis was tested for thromboelastometricRotem Gamma with the assessment of external (exTem) and internal (inTem) pathways of coagulation tests performed detection of heparin (hepTem) and cytochalasin-D-inactivation of platelets (fibTem) to assess the level of fibrinogen. Collagen-induced platelet aggregation was determined in an aggregometer CHRONO-LOG (USA). Significant deviations of the parameters of hemostasis were detected in 52 of the 66 studied patients. In group-1 (23 patients) revealed a residual effect of heparin. The effect manifested prolongation CT (clotting time) inTem to an average of 241 +/- 15 s, compared with CT hepTem--181 +/- 7. Patients in this group were in need of additional administration of protamine sulfate. Postoperative bleeding and resternotomia were observed in 3 patients of group-1. In group-2 (25 patients) CT inTem was 216 +/- 21 with significantly fewer CT hepTem (272 +/- 26). The data indicated excess of protamine sulfate. Platelets aggregation decreased compared to the norm. According to the obtained results, the addition of protamine sulfate is not required, however, in 7 cases the protamine sulfate was administered in a dose of 8.9 +/- 0.8 mg in 6 cases resternotomiya required. In the third group (n = 6) bleeding was observed in 4 patients. The difference in CT-hepCT was significant. Significant variations were revealed in the tests of the activity of the extrinsic pathway of coagulation and cytochalasin-D-induced inactivation of platelets: exMCF- 42 +/- 2 mm (normal 57 +/- 15 mm), fibMCF 5.0 +/- 0.3 mm (norm 12.8 +/- 4.3 mm). The concentration of platelets and their aggregation activity was sharply reduced. Disorders of hemostasis in the third group, designated as dilution coagulopathy. Turning thromboelastometric and impedance

  2. Interconnections between autophagy and the coagulation cascade in hepatocellular carcinoma

    PubMed Central

    Chen, K-D; Wang, C-C; Tsai, M-C; Wu, C-H; Yang, H-J; Chen, L-Y; Nakano, T; Goto, S; Huang, K-T; Hu, T-H; Chen, C-L; Lin, C-C

    2014-01-01

    Autophagy has an important role in tumor biology of hepatocellular carcinoma (HCC). Recent studies demonstrated that tissue factor (TF) combined with coagulation factor VII (FVII) has a pathological role by activating a G-protein-coupled receptor called protease-activated receptor 2 (PAR2) for tumor growth. The present study aimed to investigate the interactions of autophagy and the coagulation cascade in HCC. Seventy HCC patients who underwent curative liver resection were recruited. Immunohistochemical staining and western blotting were performed to determine TF, FVII, PAR2 and light chain 3 (LC3A/B) expressions in tumors and their contiguous normal regions. We found that the levels of autophagic marker LC3A/B-II and coagulation proteins (TF, FVII and PAR2) were inversely correlated in human HCC tissues. Treatments with TF, FVII or PAR2 agonist downregulated LC3A/B-II with an increased level of mTOR in Hep3B cells; in contrast, knockdown of TF, FVII or PAR2 increased LC3A/B. Furthermore, mTOR silencing restored the impaired expression of LC3A/B-II in TF-, FVII- or PAR2-treated Hep3B cells and activated autophagy. Last, as an in vivo correlate, we administered TF, FVII or PAR2 agonist in a NOD/severe combined immunodeficiency xenograft model and showed decreased LC3A/B protein levels in HepG2 tumors with treatments. Overall, our present study demonstrated that TF, FVII and PAR2 regulated autophagy mainly via mTOR signaling. The interaction of coagulation and autophagic pathways may provide potential targets for further therapeutic application in HCC. PMID:24853422

  3. Comparison of a novel polytitanium chloride coagulant with polyaluminium chloride: coagulation performance and floc characteristics.

    PubMed

    Zhao, Y X; Phuntsho, S; Gao, B Y; Yang, Y Z; Kim, J-H; Shon, H K

    2015-01-01

    Polymerized inorganic coagulants are increasingly being used in the water supply and wastewater treatment process, yet there is limited research on the development of polytitanium coagulants. The aim of this study is to synthesize polytitanium chloride (PTC) coagulants and investigate their coagulation behavior and floc characteristics for humic acid removal in comparison to polyaluminum chloride (PAC). The PTC samples with different B (molar ratios of OH/Ti) values were prepared using an instantaneous base-feeding method, employing sodium carbonate as the basification agent. The coagulation efficiency was significantly influenced by different B values. The results suggest that the humic acid removal increased with the increasing B value for PAC, while the inverse trend was observed for PTC. The optimum B value was chosen at 1.0 and 2.0 for PTC and PAC, respectively. Under the optimum coagulant dose and initial solution pH conditions, the PTC coagulant performed better than the PAC coagulant and the floc properties were significantly improved in terms of floc growth rate and floc size. However, the PAC coagulants produced flocs with better floc recoverability than the PTC coagulants.

  4. Transfusion and coagulation management in liver transplantation

    PubMed Central

    Clevenger, Ben; Mallett, Susan V

    2014-01-01

    There is wide variation in the management of coagulation and blood transfusion practice in liver transplantation. The use of blood products intraoperatively is declining and transfusion free transplantations take place ever more frequently. Allogenic blood products have been shown to increase morbidity and mortality. Primary haemostasis, coagulation and fibrinolysis are altered by liver disease. This, combined with intraoperative disturbances of coagulation, increases the risk of bleeding. Meanwhile, the rebalancing of coagulation homeostasis can put patients at risk of hypercoagulability and thrombosis. The application of the principles of patient blood management to transplantation can reduce the risk of transfusion. This includes: preoperative recognition and treatment of anaemia, reduction of perioperative blood loss and the use of restrictive haemoglobin based transfusion triggers. The use of point of care coagulation monitoring using whole blood viscoelastic testing provides a picture of the complete coagulation process by which to guide and direct coagulation management. Pharmacological methods to reduce blood loss include the use of anti-fibrinolytic drugs to reduce fibrinolysis, and rarely, the use of recombinant factor VIIa. Factor concentrates are increasingly used; fibrinogen concentrates to improve clot strength and stability, and prothrombin complex concentrates to improve thrombin generation. Non-pharmacological methods to reduce blood loss include surgical utilisation of the piggyback technique and maintenance of a low central venous pressure. The use of intraoperative cell salvage and normovolaemic haemodilution reduces allogenic blood transfusion. Further research into methods of decreasing blood loss and alternatives to blood transfusion remains necessary to continue to improve outcomes after transplantation. PMID:24876736

  5. Coagulation abnormalities in the cirrhotic patient.

    PubMed

    Muciño-Bermejo, Jimena; Carrillo-Esper, Raúl; Uribe, Misael; Méndez-Sánchez, Nahum

    2013-01-01

    The clotting process is a dynamic array of multiple processes which can be described in four phases: platelet plug initiation and formation, clotting process propagation by the coagulation cascade, clotting termination by antithrombotic mechanisms and clot removal by fibrinolysis. The liver plays a central role in each of these phases of clotting process, as it synthesizes the majority of coagulation factors and proteins involved in fibrinolysis as well as thrombopoeitin, which is responsible for platelet production from megakaryocytes. Many pathological processes associated with cirrhosis, such as portal hypertension and endothelial dysfunction, as well as co-morbid conditions, may also alter the coagulation process. Consequently, patients with liver disease have a disturbed balance of procoagulant and anti-coagulant factors which deviates from the normal coagulation cascade. This situation poses an additional problem in the diagnostic and therapeutic approach to this group of patients, since traditional coagulation test may not be reliable for assessing bleeding or thrombotic risk and traditional transfusional strategies may not be applicable in cirrhotic patients. In this article, we review the pathophysiological bases of coagulation abnormalities, in cirrhotic patients, the diagnostic therapeutic strategies to be followed and its impact on the clinical outcome in the cirrhotic patient.

  6. Transfusion and coagulation management in liver transplantation.

    PubMed

    Clevenger, Ben; Mallett, Susan V

    2014-05-28

    There is wide variation in the management of coagulation and blood transfusion practice in liver transplantation. The use of blood products intraoperatively is declining and transfusion free transplantations take place ever more frequently. Allogenic blood products have been shown to increase morbidity and mortality. Primary haemostasis, coagulation and fibrinolysis are altered by liver disease. This, combined with intraoperative disturbances of coagulation, increases the risk of bleeding. Meanwhile, the rebalancing of coagulation homeostasis can put patients at risk of hypercoagulability and thrombosis. The application of the principles of patient blood management to transplantation can reduce the risk of transfusion. This includes: preoperative recognition and treatment of anaemia, reduction of perioperative blood loss and the use of restrictive haemoglobin based transfusion triggers. The use of point of care coagulation monitoring using whole blood viscoelastic testing provides a picture of the complete coagulation process by which to guide and direct coagulation management. Pharmacological methods to reduce blood loss include the use of anti-fibrinolytic drugs to reduce fibrinolysis, and rarely, the use of recombinant factor VIIa. Factor concentrates are increasingly used; fibrinogen concentrates to improve clot strength and stability, and prothrombin complex concentrates to improve thrombin generation. Non-pharmacological methods to reduce blood loss include surgical utilisation of the piggyback technique and maintenance of a low central venous pressure. The use of intraoperative cell salvage and normovolaemic haemodilution reduces allogenic blood transfusion. Further research into methods of decreasing blood loss and alternatives to blood transfusion remains necessary to continue to improve outcomes after transplantation.

  7. Routine coagulation testing in intensive care.

    PubMed

    Musca, Steven; Desai, Shilpa; Roberts, Brigit; Paterson, Timothy; Anstey, Matthew

    2016-09-01

    To test a simple clinical guideline to reduce unnecessary routine testing of coagulation status. A prospective, unblinded, observational study of coagulation testing frequency before and after introduction of a simple clinical guideline. We included 253 patients admitted to a tertiary intensive care unit: 100 patients consecutively enrolled before our intervention (May - July 2015) and 153 patients consecutively enrolled after our intervention (August - September 2015). We introduced a clinical guideline and educational program in the ICU from 18 August 2015. The number of coagulation tests performed per patient bed-day, and the associated pathology costs. Over the 3-month sample period, 999 coagulation profiles were performed for 253 patients: 720 (72%) in 100 patients before, and 279 (28%) in 153 patients after our intervention. The testing frequency fell from 1.12 to 0.41 per patient bed-day (P < 0.001). A total of 463 pre-intervention coagulation profiles (64%) were classified as unnecessary, and the cost of all coagulation tests fell by 60.5% per bedday after the intervention. A simple clinical guideline and educational package reduced unnecessary coagulation tests and costs in a tertiary referral ICU.

  8. Evaluation of whole blood coagulation process by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Xu, Xiangqun; Lin, Jia

    2010-11-01

    This study was to investigate the feasibility of using optical coherence tomography (OCT) to evaluate whole blood coagulation process. Attenuation coefficients and 1/e light penetration depth (D1/e) against time of human whole blood during in vitro clot formation under static were measured from the OCT profiles of reflectance vs depth. The results obtained clearly showed that the optical parameters are able to identify three stages during the in vitro blood clotting process. It is concluded that D1/e measured by OCT is a potential parameter to quantify and follow the liquid-gel transition of blood during clotting.

  9. Minimizing Epidermal Damage In Laser Coagulation Of Superficial Blood Vessels

    NASA Astrophysics Data System (ADS)

    Scheibner, Adrianna; Anderson, R. Rox

    1989-09-01

    Laser surgery has become the most frequently used treatment for cutaneous vascular malformations. Unfortunately, using the continuous wave lasers such as the argon and argon tunable dye lasers has resulted in a fairly high risk of scarring, ranging from 5-30% compared to the pulsed light from the flashlamp-pumped dye laser. The flashlamp-pumped dye laser was designed to coagulate vessels about 100 microns in diameter. It is not effective in closing vessels much larger than this. For this reason it is important to have a modality that makes the closure of larger vessels possible without scarring. It is possible to minimize epidermal temperature rise in response to continuous wave light application by the use of a 100 micron spot size focused on the vessel tissue which will restrict coagulation to the vessels. Skin surface temperatures were measured using a thermocouple. When coherent light was delivered from an argon (514 nm) and argon tunable dye (577 nm) lasers, a 100 micron spot power of 0.1 watt and one second exposures were used, the mean skin surface temperature rise was 6 ± 2 degrees celsius. By contrast, a 1000 micron spot, power of 1 watt and one second exposure resulted in a mean temperature rise of 20 ± 2 degrees celsius. These measurements were confirmed using an Inframetrics thermal camera. Treatment of portwine stains using this technique has substantially reduced the incidence of post-laser scarring.

  10. Reaction-diffusion waves of blood coagulation.

    PubMed

    Galochkina, Tatiana; Bouchnita, Anass; Kurbatova, Polina; Volpert, Vitaly

    2017-06-01

    One of the main characteristics of blood coagulation is the speed of clot growth. In the current work we consider a mathematical model of the coagulation cascade and study existence, stability and speed of propagation of the reaction-diffusion waves of blood coagulation. We also develop a simplified one-equation model that reflects the main features of the thrombin wave propagation. For this equation we estimate the wave speed analytically. The resulting formulas provide a good approximation for the speed of wave propagation in a more complex model as well as for the experimental data. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Acute Disseminated Intravascular Coagulation in Neuroendocrine Carcinoma

    PubMed Central

    Teh, Ru-Wen; Tsoi, Daphne T.

    2012-01-01

    Malignancy is a common cause of disseminated intravascular coagulation and usually presents as a chronic disorder in solid organ tumours. We present a rare case of recurrent acute disseminated intravascular coagulation in neuroendocrine carcinoma after manipulation, firstly, by core biopsy and, later, by cytotoxic therapy causing a release of procoagulants and cytokines from lysed tumour cells. This is reminiscent of tumour lysis syndrome where massive quantities of intracellular electrolytes and nucleic acid are released, causing acute metabolic imbalance and renal failure. This case highlights the potential complication of acute disseminated intravascular coagulation after trauma to malignant cells. PMID:23139666

  12. A simple method for estimation of coagulation efficiency in mixed aerosols. [environmental pollution control

    NASA Technical Reports Server (NTRS)

    Dimmick, R. L.; Boyd, A.; Wolochow, H.

    1975-01-01

    Aerosols of KBr and AgNO3 were mixed, exposed to light in a glass tube and collected in the dark. About 15% of the collected material was reduced to silver upon development. Thus, two aerosols of particles that react to form a photo-reducible compound can be used to measure coagulation efficiency.

  13. Ferric coagulant recovered from coagulation sludge and its recycle in chemically enhanced primary treatment.

    PubMed

    Xu, G R; Yan, Z C; Wang, N; Li, G B

    2009-01-01

    An investigation was conducted to study the feasibility of ferric coagulant recovery from chemical sludge and its recycle in chemically enhanced primary treatment (CEPT) to make the process more cost-effective, as well as reduce sludge volume. The optimum conditions and efficiency of the acidification for ferric coagulant recovery from coagulation sludge were investigated. Experimental results showed that the recovered coagulants can be used in CEPT and the pollutants removal efficiency is similar to that of fresh coagulant, and for some aspects the effect of recovered coagulants is better than that of fresh ones, such as turbidity removal. Although some substances will be enriched during recycle, they have little effect on treated wastewater quality. Acidification condition also had significant influence on reduction of sludge volume. The efficiency of coagulant recovery had a linear relationship with sludge reduction. Experiments verify that it would be a sustainable and cost-effective way to recover ferric coagulant from coagulation sludge in water treatment and chemical wastewater treatment, and then recycle it to CEPT, as well as reduce sludge volume.

  14. Markers of coagulation activation after hepatic resection for cancer: evidence of sustained upregulation of coagulation.

    PubMed

    Weinberg, L; Scurrah, N; Parker, F C; Dauer, R; Marshall, J; McCall, P; Story, D; Smith, C; McNicol, L

    2011-09-01

    We investigated the possibility that despite postoperative derangements of routine laboratory coagulation tests, markers of coagulation activation and thrombin generation would be normal or increased in patients undergoing hepatic resection for cancer In addition to the conventional coagulation tests prothrombin time and activated partial thromboplastin time, we measured select markers of coagulation activation prothrombin fragments 1 and 2 (PF1 + 2), thrombin-antithrombin complexes and plasma von Willebrand Factor antigen in 21 patients undergoing hepatic resection. The impact of hepatic resection on coagulation and fibrinolysis was studied with thromboelastography. Preoperatively, routine laboratory coagulation and liver function tests were normal in all patients. On the first postoperative day, prothrombin time was prolonged (range 16 to 22 seconds) in eight patients (38%). For these patients, thromboelastography was normal in six (75%), PF1 + 2 was elevated in four (50%), and thrombin-antithrombin complexes and von Willebrand Factor antigen were elevated in all, which was evidence of acute phase reaction, sustained coagulation factor turnover and activation. By the fifth postoperative day, despite normalisation of prothrombin time, markers of increased coagulation activity remained greater than 85% of baseline values. The findings indicate that in patients undergoing liver resection for cancer, there is significant and prolonged postoperative activation of the haemostatic system despite routine coagulation tests being normal or even prolonged. Before considering therapeutic interventions an integrated approach to interpreting haematological data with clinical correlation is essential.

  15. Effects of Al-coagulant sludge characteristics on the efficiency of coagulants recovery by acidification.

    PubMed

    Chen, Yi-Jui; Wang, Wen-May; Wei, Ming-Jun; Chen, Jiann-Long; He, Ju-Liang; Chiang, Kung-Yuh; Wu, Chih-Chao

    2012-12-01

    This study evaluated the effects of Al-coagulant sludge characteristics on the efficiency ofcoagulant recovery by acidification with H2SO4. Two sludge characteristics were studied: types of coagulant and textures of the suspended solid in raw water. The coagulant types are aluminium sulphate and polyaluminium chloride (PACl); the textures of the suspended solid are sand-based and clay-based. Efficiency of aluminium recovery at a pH of 2 was compared for different sludges obtained from water treatment plants in Taiwan. The results showed that efficiency of aluminium recovery from sludge containing clayey particles was higher than that from sludge containing sandy particles. As for the effect of coagulant types, the aluminium recovery efficiency for sludge using PACl ranged between 77% and 100%, whereas it ranged between 65% and 72% for sludge using aluminium sulphate as the coagulant. This means using PACl as the coagulant could result in higher recovery efficiency of coagulant and be beneficial for water treatment plants where renewable materials and waste reduction as the factors for making decisions regarding plant operations. However, other metals, such as manganese, could be released with aluminium during the acidification process and limit the use of the recovered coagulants. It is suggested that the recovered coagulants be used in wastewater treatment processes.

  16. Coagulation testing in the perioperative period.

    PubMed

    Thiruvenkatarajan, Venkatesan; Pruett, Ashlee; Adhikary, Sanjib Das

    2014-09-01

    Perioperative coagulation management is a complex task that has a significant impact on the perioperative journey of patients. Anaesthesia providers play a critical role in the decision-making on transfusion and/or haemostatic therapy in the surgical setting. Various tests are available in identifying coagulation abnormalities in the perioperative period. While the rapidly available bedside haemoglobin measurements can guide the transfusion of red blood cells, blood product administration is guided by many in vivo and in vitro tests. The introduction of newer anticoagulant medications and the implementation of the modified in vivo coagulation cascade have given a new dimension to the field of perioperative transfusion medicine. A proper understanding of the application and interpretation of the coagulation tests is vital for a good perioperative outcome.

  17. Coagulation testing in the perioperative period

    PubMed Central

    Thiruvenkatarajan, Venkatesan; Pruett, Ashlee; Adhikary, Sanjib Das

    2014-01-01

    Perioperative coagulation management is a complex task that has a significant impact on the perioperative journey of patients. Anaesthesia providers play a critical role in the decision-making on transfusion and/or haemostatic therapy in the surgical setting. Various tests are available in identifying coagulation abnormalities in the perioperative period. While the rapidly available bedside haemoglobin measurements can guide the transfusion of red blood cells, blood product administration is guided by many in vivo and in vitro tests. The introduction of newer anticoagulant medications and the implementation of the modified in vivo coagulation cascade have given a new dimension to the field of perioperative transfusion medicine. A proper understanding of the application and interpretation of the coagulation tests is vital for a good perioperative outcome. PMID:25535418

  18. A Numerical Study on Microwave Coagulation Therapy

    DTIC Science & Technology

    2013-01-01

    treated by applying localized heat to cancerous tissues, often in combination with chemotherapy or radiotherapy. Microwave coagulation therapy is one...such clinical technique for treating hepatocellular carcinoma. In the treatment, a thin microwave antenna is inserted into the cancerous tissue and...the microwave energy heats up the tumor, killing the cancer cells by producing a coagulated region. Numerical models of microwave cancer therapy have

  19. Dust Coagulation in Protoplanetary Accretion Disks

    NASA Technical Reports Server (NTRS)

    Schmitt, W.; Henning, Th.; Mucha, R.

    1996-01-01

    The time evolution of dust particles in circumstellar disk-like structures around protostars and young stellar objects is discussed. In particular, we consider the coagulation of grains due to collisional aggregation. The coagulation of the particles is calculated by solving numerically the non-linear Smoluchowski equation. The different physical processes leading to relative velocities between the grains are investigated. The relative velocities may be induced by Brownian motion, turbulence and drift motion. Starting from different regimes which can be identified during the grain growth we also discuss the evolution of dust opacities. These opacities are important for both the derivation of the circumstellar dust mass from submillimeter/millimeter continuum observations and the dynamical behavior of the disks. We present results of our numerical studies of the coagulation of dust grains in a turbulent protoplanetary accretion disk described by a time-dependent one-dimensional (radial) alpha-model. For several periods and disk radii, mass distributions of coagulated grains have been calculated. From these mass spectra, we determined the corresponding Rosseland mean dust opacities. The influence of grain opacity changes due to dust coagulation on the dynamical evolution of a protostellar disk is considered. Significant changes in the thermal structure of the protoplanetary nebula are observed. A 'gap' in the accretion disk forms at the very frontier of the coagulation, i.e., behind the sublimation boundary in the region between 1 and 5 AU.

  20. [Incidental finding of pathological coagulation parameters].

    PubMed

    Luxembourg, B; Lindhoff-Last, E

    2014-10-01

    Pathological coagulation parameters may reflect life-threatening hemorrhagic or thromboembolic diseases but may also be a laboratory result without any clinical significance, result from in vitro phenomena or preanalytical errors. This article gives an overview of potential pitfalls in coagulation diagnostics, lists the differential diagnoses of pathological coagulation parameters and describes further steps in the diagnostic approach to clarify pathological results. The focus lies on coagulation parameters that are frequently determined in routine clinical investigations, e.g. platelet count, prothrombin time, activated partial thromboplastin time (aPTT) and fibrinogen. Besides heparin, fondaparinux, danaparoid, and vitamin K antagonists, direct factor Xa inhibitors and direct thrombin inhibitors are nowadays available for therapeutic anticoagulation. This article gives an overview of the influence of anticoagulants on coagulation parameters which depends on the dose, the time of the last administration, as well as the method used for the determination of coagulation parameters. Moreover, common reasons for elevation of the fibrin degradation product D-dimer are presented. The clinical utility of D-dimer assays is limited by their poor specificity. Elevated D-dimer concentrations can be found in various diseases and also under normal physiological circumstances (e.g. in the elderly). Thus, the most useful clinical application of D-dimer is evidence of normal values to essentially rule out venous thromboembolism.

  1. Removal of silver nanoparticles by coagulation processes.

    PubMed

    Sun, Qian; Li, Yan; Tang, Ting; Yuan, Zhihua; Yu, Chang-Ping

    2013-10-15

    Commercial use of silver nanoparticles (AgNPs) will lead to a potential route for human exposure via potable water. Coagulation followed by sedimentation, as a conventional technique in the drinking water treatment facilities, may become an important barrier to prevent human from AgNP exposures. This study investigated the removal of AgNP suspensions by four regular coagulants. In the aluminum sulfate and ferric chloride coagulation systems, the water parameters slightly affected the AgNP removal. However, in the poly aluminum chloride and polyferric sulfate coagulation systems, the optimal removal efficiencies were achieved at pH 7.5, while higher or lower of pH could reduce the AgNP removal. Besides, the increasing natural organic matter (NOM) would reduce the AgNP removal, while Ca(2+) and suspended solids concentrations would also affect the AgNP removal. In addition, results from the transmission electron microscopy and X-ray diffraction showed AgNPs or silver-containing nanoparticles were adsorbed onto the flocs. Finally, natural water samples were used to validate AgNP removal by coagulation. This study suggests that in the case of release of AgNPs into the source water, the traditional water treatment process, coagulation/sedimentation, can remove AgNPs and minimize the silver ion concentration under the well-optimized conditions. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Perioperatively acquired disorders of coagulation

    PubMed Central

    Grottke, Oliver; Fries, Dietmar; Nascimento, Bartolomeu

    2015-01-01

    Purpose of review To provide an overview of acquired coagulopathies that can occur in various perioperative clinical settings. Also described are coagulation disturbances linked to antithrombotic medications and currently available strategies to reverse their antithrombotic effects in situations of severe hemorrhage. Recent findings Recent studies highlight the link between low fibrinogen and decreased fibrin polymerization in the development of acquired coagulopathy. Particularly, fibrin(ogen) deficits are observable after cardiopulmonary bypass in cardiac surgery, on arrival at the emergency room in trauma patients, and with ongoing bleeding after child birth. Regarding antithrombotic therapy, although new oral anticoagulants offer the possibility of efficacy and relative safety compared with vitamin K antagonists, reversal of their anticoagulant effect with nonspecific agents, including prothrombin complex concentrate, has provided conflicting results. Specific antidotes, currently being developed, are not yet licensed for clinical use, but initial results are promising. Summary Targeted hemostatic therapy aims to correct coagulopathies in specific clinical settings, and reduce the need for allogeneic transfusions, thus preventing massive transfusion and its deleterious outcomes. Although there are specific guidelines for reversing anticoagulation in patients treated with antiplatelet agents or warfarin, there is currently little evidence to advocate comprehensive recommendations to treat drug-induced coagulopathy associated with new oral anticoagulants. PMID:25734869

  3. Coagulation algorithms with size binning

    NASA Technical Reports Server (NTRS)

    Statton, David M.; Gans, Jason; Williams, Eric

    1994-01-01

    The Smoluchowski equation describes the time evolution of an aerosol particle size distribution due to aggregation or coagulation. Any algorithm for computerized solution of this equation requires a scheme for describing the continuum of aerosol particle sizes as a discrete set. One standard form of the Smoluchowski equation accomplishes this by restricting the particle sizes to integer multiples of a basic unit particle size (the monomer size). This can be inefficient when particle concentrations over a large range of particle sizes must be calculated. Two algorithms employing a geometric size binning convention are examined: the first assumes that the aerosol particle concentration as a function of size can be considered constant within each size bin; the second approximates the concentration as a linear function of particle size within each size bin. The output of each algorithm is compared to an analytical solution in a special case of the Smoluchowski equation for which an exact solution is known . The range of parameters more appropriate for each algorithm is examined.

  4. Does Activation of the Blood Coagulation Cascade Play a Role in Malaria Pathogenesis?

    PubMed Central

    Francischetti, Ivo M. B.

    2010-01-01

    Plasmodium falciparum infection is often associated with a procoagulant state. Recent identification of tissue factor (TF) in the brain endothelium of patients who died from cerebral malaria casts new light in our understanding of the coagulation disorder found in P. falciparum infection. It has also been revealed that parasitized red blood cells (pRBC) support assembly of multimolecular coagulation complexes. In this article, the role of TF expression by the endothelium and amplification of the coagulation cascade by pRBC and/or activated platelets—particularly at sequestration sites— is discussed as crucial events in mounting and sustaining a coagulation–inflammation cycle that contributes to organ dysfunction and coma in P. falciparum malaria. PMID:18467176

  5. The effect of labour on the coagulation system in the term neonate.

    PubMed

    Kulkarni, A A; Osmond, M; Bapir, M; Riddell, A; Smith, C; Lee, C A; Kadir, R A

    2013-07-01

    The coagulation system of the foetus is markedly different from that of adults. To assess the influence of maternal age, mode of delivery and intrapartum events, and foetal gender and weight on the foetal coagulation system. Cord blood was collected from 154 healthy pregnant women, with gestational age 37 - 42 weeks at birth. Mann-Whitney test was used for analysis of binary data and continuous variables were analysed using Pearson's correlation coefficient. Mean cord blood levels of FVIII:C, VWF:Ag, VWF:CB, FIX, FXI, FXII and plasminogen were significantly higher in babies delivered after labour, compared to those delivered after an elective caesarean. Mean cord blood levels of FII (P = 0.003), FV (P = 0.009), FVII (P = 0.0004) and FX (P = 0.0009) were significantly lower in the babies with meconium stained liquor in labour, compared with those with clear liquor. Augmentation with oxytocin, instrumental delivery, did not affect any of the factor levels and duration of labour did not have an effect on the level of coagulation proteins in cord blood. This study provides valuable information about effect of labour on the coagulation system of the foetus. It is concluded that, in cord blood, the results of coagulation parameters in the newborn baby should be considered in light of mode of delivery and events of labour. © 2013 John Wiley & Sons Ltd.

  6. Micro-electromechanical film bulk acoustic sensor for plasma and whole blood coagulation monitoring.

    PubMed

    Chen, Da; Song, Shuren; Ma, Jilong; Zhang, Zhen; Wang, Peng; Liu, Weihui; Guo, Qiuquan

    2017-05-15

    Monitoring blood coagulation is an important issue in the surgeries and the treatment of cardiovascular diseases. In this work, we reported a novel strategy for the blood coagulation monitoring based on a micro-electromechanical film bulk acoustic resonator. The resonator was excited by a lateral electric field and operated under the shear mode with a frequency of 1.9GHz. According to the apparent step-ladder curves of the frequency response to the change of blood viscoelasticity, the coagulation time (prothrombin time) and the coagulation kinetics were measured with the sample consumption of only 1μl. The procoagulant activity of thromboplastin and the anticoagulant effect of heparin on the blood coagulation process were illustrated exemplarily. The measured prothrombin times showed a good linear correlation with R(2)=0.99969 and a consistency with the coefficient of variation less than 5% compared with the commercial coagulometer. The proposed film bulk acoustic sensor, which has the advantages of small size, light weight, low cost, simple operation and little sample consumption, is a promising device for miniaturized, online and automated analytical system for routine diagnostics of hemostatic status and personal health monitoring. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Effect of fibrinogen on blood coagulation detected by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Xu, Xiangqun; Teng, Xiangshuai

    2015-05-01

    Our previous work demonstrated that an optical coherence tomography (OCT) technique and the parameter 1/e light penetration depth (d1/e) were able to characterize the whole blood coagulation process in contrast to existing optical tests that are performed on plasma samples. To evaluate the feasibility of the technique for quantifying the effect of fibrinogen (Fbg) on blood coagulation, a dynamic study of d1/e of blood in various Fbg concentrations was performed in static state. Two groups of blood samples of hematocrit (HCT) in 35, 45, and 55% were reconstituted of red blood cells with: 1) treated plasma with its intrinsic Fbg removed and commercial Fbg added (0-8 g L-1) and 2) native plasma with commercial Fbg added (0-8 g L-1). The results revealed a typical behavior due to coagulation induced by calcium ions and the clotting time is Fbg concentration-dependent. The clotting time was decreased by the increasing amount of Fbg in both groups. Besides, the blood of lower HCT with various levels of Fbg took shorter time to coagulate than that of higher HCT. Consequently, the OCT method is a useful and promising tool for the detection of blood-coagulation processes induced with different Fbg levels.

  8. Effects of haemodilution on the optical properties of blood during coagulation studied by optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Liu, B.; Liu, Y.; Wei, H.; Yang, X.; Wu, G.; Guo, Z.; Yang, H.; He, Y.; Xie, S.

    2016-11-01

    We report an investigation of the effects of blood dilution with hypertonic (7.5 %) and normal (0.9 %) saline on its optical properties during coagulation in vitro using optical coherence tomography. The light penetration depth and attenuation coefficient are obtained from the dependences of reflectance on the depth. Normal whole blood has served as the control group. The average coagulation time is equal to 420 +/- 16, 418 +/- 16 and 358 +/- 14 {\\text{s}} with blood volume replacement of 2 %, 11 %, and 20 % by 0.9 % normal saline, respectively. With 2 %, 11% and 20% blood volume replacement with 7.5 % hypertonic saline, the average coagulation time is 422 +/- 17, 1160 +/- 45 and 1730 +/- 69 {\\text{s}}, respectively. For normal whole blood, the average coagulation time amounts to 425 +/- 19 {\\text{s}}. it is shown that dilution with normal saline has a procoagulant effect when it replaces 20 % of blood volume, and hypertonic saline has an anticoagulant effect if it replaces 11 % or more of blood volume. It is concluded that optical coherence tomography is a potential technique to quantify and monitor the liquid - gel transition during the coagulation process of blood diluted by normal and hypertonic saline.

  9. Effect of fibrinogen on blood coagulation detected by optical coherence tomography.

    PubMed

    Xu, Xiangqun; Teng, Xiangshuai

    2015-05-21

    Our previous work demonstrated that an optical coherence tomography (OCT) technique and the parameter 1/e light penetration depth (d1/e) were able to characterize the whole blood coagulation process in contrast to existing optical tests that are performed on plasma samples. To evaluate the feasibility of the technique for quantifying the effect of fibrinogen (Fbg) on blood coagulation, a dynamic study of d1/e of blood in various Fbg concentrations was performed in static state. Two groups of blood samples of hematocrit (HCT) in 35, 45, and 55% were reconstituted of red blood cells with: 1) treated plasma with its intrinsic Fbg removed and commercial Fbg added (0-8 g L(-1)); and 2) native plasma with commercial Fbg added (0-8 g L(-1)). The results revealed a typical behavior due to coagulation induced by calcium ions and the clotting time is Fbg concentration-dependent. The clotting time was decreased by the increasing amount of Fbg in both groups. Besides, the blood of lower HCT with various levels of Fbg took shorter time to coagulate than that of higher HCT. Consequently, the OCT method is a useful and promising tool for the detection of blood-coagulation processes induced with different Fbg levels.

  10. Determining the efficiency of subjecting finely dispersed emulsions to physical coagulation in a packed layer under turbulent conditions

    NASA Astrophysics Data System (ADS)

    Laptev, A. G.; Basharov, M. M.; Farakhova, A. I.

    2013-09-01

    The process through which small droplets contained in emulsions are physically coagulated on the surface of random packing elements is considered. The theory of turbulent migration of a finely dispersed phase is used for determining the coagulation efficiency. Expressions for calculating coagulation efficiency and turbulent transfer rate are obtained by applying models of a turbulent boundary layer. An example of calculating the enlargement of water droplets in hydrocarbon medium represented by a wide fraction of light hydrocarbons (also known as natural gas liquid) is given. The process flowchart of a system for removing petroleum products from effluent waters discharged from the Kazan TETs-1 cogeneration station is considered. Replacement of the mechanical filter by a thin-layer settler with a coagulator is proposed.

  11. Solutions of the coagulation equation with time-dependent coagulation rates. [For stellar formation mass functions

    SciTech Connect

    Lejeune, C.; Bastien, P.

    1986-10-01

    In attempting to reproduce the initial stellar mass function, the authors solved analytically the coagulation equation with an explicit time dependence in the coagulation rate in order to simulate the gravitational collapse of the fragments upon themselves as they move within the progenitor cloud. Two separate cases have been studied, with and without a mass dependence in the coagulation rate. The solutions show that: (1) inclusion of self-gravitation can change the results to the point of preventing coalescence to work altogether, depending on the values of the two free parameters; (2) the precise form of the mass dependence of the coagulation rate is not of prime importance in most situations of astrophysical interest; (3) coagulation alone is not sufficient to yield a realistic mass spectrum, and fragmentation must also be taken into account. 30 references.

  12. Global coagulation in myeloproliferative neoplasms.

    PubMed

    Tripodi, Armando; Chantarangkul, Veena; Gianniello, Francesca; Clerici, Marigrazia; Lemma, Laura; Padovan, Lidia; Gatti, Loredana; Mannucci, Pier Mannuccio; Peyvandi, Flora

    2013-12-01

    In spite of their recognized risk of thrombosis, patients with myeloproliferative neoplasms (MPN) show little or no abnormalities of traditional coagulation tests, perhaps because these are unable to represent the balance between pro- and anticoagulants nor the effect of platelets and blood cells. We investigated whether global tests such as thrombin generation in platelet-rich plasma (PRP) or thromboelastometry in whole blood were able to detect signs of procoagulant imbalance in MPN. The endogenous thrombin potential (ETP) of 111 patients and 89 controls was measured in PRP with platelet count adjusted to the original patient- or control-count. Testing was performed with and without thrombomodulin (the physiological protein C activator) and results were expressed as ETP ratios (with/without thrombomodulin). High ETP ratios reflect resistance to thrombomodulin and were taken as indexes of procoagulant imbalance. Patients were also investigated by thromboelastometry that provides such parameters as the clot formation time (CFT) and maximal clot firmness (MCF). Short CFT or high MCF were taken as indexes of procoagulant imbalance. ETP ratios were higher in patients than in controls and were directly correlated with platelet counts and inversely with the plasma levels of free protein S, protein C and antithrombin. Patients on hydroxyurea had lower ETP ratios than those on other treatments. CFT was shorter and MCF was greater in patients than controls; CFT and MCF were correlated with platelet counts. In conclusion, patients with MPN display a procoagulant imbalance detectable by thrombin generation and thromboelastometry. These tests might be useful in the frame of clinical trials to assess their association with the occurrence of thrombosis and with the effect of therapeutic strategies in MPN.

  13. Microrheological Coagulation Assay Exploiting Micromechanical Resonators.

    PubMed

    Padovani, Francesco; Duffy, James; Hegner, Martin

    2017-01-03

    Rheological measurements in biological liquids yield insights into homeostasis and provide information on important molecular processes that affect fluidity. We present a fully automated cantilever-based method for highly precise and sensitive measurements of microliter sample volumes of human blood plasma coagulation (0.009 cP for viscosity range 0.5-3 cP and 0.0012 g/cm(3) for density range 0.9-1.1 g/cm(3)). Microcantilever arrays are driven by a piezoelectric element, and resonance frequencies and quality factors of sensors that change over time are evaluated. A highly accurate approximation of the hydrodynamic function is introduced that correlates resonance frequency and quality factor of cantilever beams immersed in a fluid to the viscosity and density of that fluid. The theoretical model was validated using glycerol reference solutions. We present a surface functionalization protocol that allows minimization of unspecific protein adsorption onto cantilevers. Adsorption leads to measurement distortions and incorrect estimation of the fluid parameters (viscosity and density). Two hydrophilic terminated self-assembled monolayers (SAMs) sensor surfaces are compared to a hydrophobic terminated SAM coating. As expected, the hydrophobic modified surfaces induced the highest mass adsorption and could promote conformational changes of the proteins and subsequent abnormal biological activity. Finally, the activated partial thromboplastin time (aPTT) coagulation assay was performed, and the viscosity, density, and coagulation rate of human blood plasma were measured along with the standard coagulation time. The method could extend and improve current coagulation testing.

  14. [Investigation of coagulation time: PT and APTT].

    PubMed

    Ramakers, Christian; van der Heul, Cees; van Wijk, Eduard M

    2012-01-01

    The first case report describes an extremely prolonged activated partial thromboplastin time (APTT) in a patient with no history of increased bleeding tendency. Heparin use was excluded. The APTT mixing study combined with the medical history suggests a deficiency in one of the non-essential coagulation factors. This was confirmed by factor XII activity of <1%. The second case report describes a prolonged APTT in a patient with no history of increased bleeding tendency. The negative bleeding tendency in combination with a failure of the mixing study to correct the coagulation assay results suggests a factor inhibitor, most probably lupus anticoagulant. Indeed, the lupus anticoagulant was positive and the anti-cardiolipin antibody titre was also positive. Aberrations in the process of haemostasis can be efficiently screened using a platelet count, an APTT, a PT and a thorough physical examination combined with a thorough medical history taking. Common causes of prolonged PT and/or APTT are the use of oral anticoagulants or heparin, vitamin K deficiency and liver disease. Other causes include coagulation factor deficiencies, coagulation factor inhibitors and diffuse intravascular coagulation.

  15. Magnetic particle imaging of blood coagulation

    SciTech Connect

    Murase, Kenya Song, Ruixiao; Hiratsuka, Samu

    2014-06-23

    We investigated the feasibility of visualizing blood coagulation using a system for magnetic particle imaging (MPI). A magnetic field-free line is generated using two opposing neodymium magnets and transverse images are reconstructed from the third-harmonic signals received by a gradiometer coil, using the maximum likelihood-expectation maximization algorithm. Our MPI system was used to image the blood coagulation induced by adding CaCl{sub 2} to whole sheep blood mixed with magnetic nanoparticles (MNPs). The “MPI value” was defined as the pixel value of the transverse image reconstructed from the third-harmonic signals. MPI values were significantly smaller for coagulated blood samples than those without coagulation. We confirmed the rationale of these results by calculating the third-harmonic signals for the measured viscosities of samples, with an assumption that the magnetization and particle size distribution of MNPs obey the Langevin equation and log-normal distribution, respectively. We concluded that MPI can be useful for visualizing blood coagulation.

  16. Coagulation management in patients undergoing neurosurgical procedures.

    PubMed

    Robba, Chiara; Bertuetti, Rita; Rasulo, Frank; Bertuccio, Alessando; Matta, Basil

    2017-10-01

    Management of coagulation in neurosurgical procedures is challenging. In this contest, it is imperative to avoid further intracranial bleeding. Perioperative bleeding can be associated with a number of factors, including anticoagulant drugs and coagulation status but is also linked to the characteristic and the site of the intracranial disorder. The aim of this review will be to focus primarily on the new evidence regarding the management of coagulation in patients undergoing craniotomy for neurosurgical procedures. Antihemostatic and anticoagulant drugs have shown to be associated with perioperative bleeding. On the other hand, an increased risk of venous thromboembolism and hypercoagulative state after elective and emergency neurosurgery, in particular after brain tumor surgery, has been described in several patients. To balance the risk between thrombosis and bleeding, it is important to be familiar with the perioperative changes in coagulation and with the recent management guidelines for anticoagulated patients undergoing neurosurgical procedures, in particular for those taking new direct anticoagulants. We have considered the current clinical trials and literature regarding both safety and efficacy of deep venous thrombosis prophylaxis in the neurosurgical population. These were mainly trials concerning both elective surgical and intensive care patients with a poor grade intracranial bleed or multiple traumas with an associated severe traumatic brain injury (TBI). Coagulation management remains a major issue in patients undergoing neurosurgical procedures. However, in this field of research, literature quality is poor and further studies are necessary to identify the best strategies to minimize risks in this group of patients.

  17. Viscoelastic coagulation testing: technology, applications, and limitations.

    PubMed

    McMichael, Maureen A; Smith, Stephanie A

    2011-06-01

    Use of viscoelastic point-of-care (POC) coagulation instrumentation is relatively new to veterinary medicine. In human medicine, this technology has recently undergone resurgence owing to its capacity to detect hypercoagulability. The lack of sensitive tests for detecting hypercoagulable states, along with our current understanding of in vivo coagulation, highlights the deficiencies of standard coagulation tests, such as prothrombin and partial thromboplastin times, which are performed on platelet-poor plasma. Viscoelastic coagulation analyzers can provide an assessment of global coagulation, from the beginning of clot formation to fibrinolysis, utilizing whole blood. In people, use of this technology has been reported to improve management of hemostasis during surgery and decrease usage of blood products and is being used as a rapid screen for hypercoagulability. In veterinary medicine, clinical use of viscoelastic technology has been reported in dogs, cats, foals, and adult horses. This article will provide an overview of the technology, reagents and assays, applications in human and veterinary medicine, and limitations of the 3 viscoelastic POC analyzers in clinical use. ©2011 American Society for Veterinary Clinical Pathology.

  18. Fibrinolysis and the control of blood coagulation

    PubMed Central

    Chapin, John C.; Hajjar, Katherine A.

    2014-01-01

    Fibrin plays an essential role in hemostasis as both the primary product of the coagulation cascade and the ultimate substrate for fibrinolysis. Fibrinolysis efficiency is greatly influenced by clot structure, fibrinogen isoforms and polymorphisms, the rate of thrombin generation, the reactivity of thrombus-associated cells such as platelets, and the overall biochemical environment. Regulation of the fibrinolytic system, like that of the coagulation cascade, is accomplished by a wide array of cofactors, receptors, and inhibitors. Fibrinolytic activity can be generated either on the surface of a fibrin-containing thrombus, or on cells that express profibrinolytic receptors. In a widening spectrum of clinical disorders, acquired and congenital defects in fibrinolysis contribute to disease morbidity, and new assays of global fibrinolysis now have potential predictive value in multiple clinical settings. Here, we summarize the basic elements of the fibrinolytic system, points of interaction with the coagulation pathway, and some recent clinical advances. PMID:25294122

  19. Coagulation-membrane filtration of Chlorella vulgaris.

    PubMed

    Lee, Duu-Jong; Liao, Guan-Yu; Chang, Yin-Ru; Chang, Jo-Shu

    2012-03-01

    Filtration-based separation of Chlorella vulgaris, a species with excellent potential for CO(2) capture and lipid production, was investigated using a surface-modified hydrophilic polytetrafluoroethylene (PTFE) membrane. Coagulation using polyaluminum chloride (PACl) attained maximum turbidity removal at 200 mg L(-1) as Al(2)O(3). The membrane filtration flux at 1 bar increased as the PACl dose increased, regardless of overdosing in the coagulation stage. The filtered cake at the end of filtration tests peaked in solid content at 10 mg L(-1) as Al(2)O(3), reaching 34% w/w, roughly two times that of the original suspension. Differential scanning calorimetry (DSC) tests demonstrate that the cake with minimum water-solid binding strength produced the driest filter cake. Coagulation using 10 mg L(-1) PACl as Al(2)O(3), followed by PTFE membrane filtration at 1 bar, is an effective process for harvesting C. vulgaris from algal froth.

  20. Prostate cancer: beware of disseminated intravascular coagulation

    PubMed Central

    Desai, Mihir; John, Babbin; Evans, Gillian; Eddy, Ben

    2015-01-01

    Disseminated intravascular coagulation (DIC) is a pathological systemic condition resulting from aberrant activation of the coagulation system. It is characterised by the release and activation of procoagulants into the blood, with an associated consumption coagulopathy. Its association with solid and haematological malignancies is well described in literature. This case describes an elderly man, known to have prostate cancer, who following transurethral resection of the prostate developed DIC with haematuria, spontaneous ecchymoses and mucosal bleeding. Subsequent investigations revealed a prostate-specific antigen (PSA) >1000 µg/L, and staging CT showed multiple sclerotic metastatic lesions affecting the thoracic and lumbar vertebra, as well as infiltration into his left femur. Coagulation normalised with blood products and vitamin K within 1 week, and the patient responded to antiandrogen therapy with a reduction in pain and PSA on discharge. PMID:25819815

  1. Coagulation of carbon clusters in detonation front

    NASA Astrophysics Data System (ADS)

    Kupershtokh, A. L.; Ershov, A. P.; Medvedev, D. A.

    1996-05-01

    During the detonation synthesis, diamonds of ˜3 nm in size are produced from the excess carbon released in explosion. Coagulation occurs generally well below the melting temperature. Molecular dynamic simulations within the framework of simple Lennard-Jones model showed important features of interacting carbon clusters: 1) Coagulation is exothermic, and small clusters merge as liquid drops. Clusters larger than ˜3 nm unite keeping their shape, but surface atoms are in quasimolten state and can migrate between two grains. This "wetting" is rather slow. For small clusters there exist considerable temperature fluctuations due to interaction with the thermal bath. 2) Coagulation is accompanied by strong tensions. Both positive and negative pressure phases during the collision can reach ˜30 GPa. This can explain why the region of good diamond yield lies on P-T plane much higher than the graphite-diamond transition line.

  2. Fibrinolysis and the control of blood coagulation.

    PubMed

    Chapin, John C; Hajjar, Katherine A

    2015-01-01

    Fibrin plays an essential role in hemostasis as both the primary product of the coagulation cascade and the ultimate substrate for fibrinolysis. Fibrinolysis efficiency is greatly influenced by clot structure, fibrinogen isoforms and polymorphisms, the rate of thrombin generation, the reactivity of thrombus-associated cells such as platelets, and the overall biochemical environment. Regulation of the fibrinolytic system, like that of the coagulation cascade, is accomplished by a wide array of cofactors, receptors, and inhibitors. Fibrinolytic activity can be generated either on the surface of a fibrin-containing thrombus, or on cells that express profibrinolytic receptors. In a widening spectrum of clinical disorders, acquired and congenital defects in fibrinolysis contribute to disease morbidity, and new assays of global fibrinolysis now have potential predictive value in multiple clinical settings. Here, we summarize the basic elements of the fibrinolytic system, points of interaction with the coagulation pathway, and some recent clinical advances.

  3. Coagulation characteristics of titanium (Ti) salt coagulant compared with aluminum (Al) and iron (Fe) salts.

    PubMed

    Zhao, Y X; Gao, B Y; Shon, H K; Cao, B C; Kim, J-H

    2011-01-30

    In this study, the performance of titanium tetrachloride (TiCl(4)) coagulation and flocculation is compared with commonly used coagulants such as aluminum sulfate (Al(2)(SO(4))(3)), polyaluminum chloride (PACl), iron chloride (FeCl(3)), and polyferric sulfate (PFS) in terms of water quality parameters and floc properties. TiCl(4) flocculation achieved higher removal of UV(254) (98%), dissolved organic carbon (DOC) (84%) and turbidity (93%) than other conventional coagulants. Charge neutralization and physical entrapment of colloids within coagulant precipitates and adsorption, seemed to play a significant role during TiCl(4) flocculation, while the main mechanism for conventional coagulants was bridge-aggregation and adsorption. The aggregated flocs after TiCl(4) flocculation showed the fastest growth rate compared to the other coagulants, with the largest floc size (801 μm) occurring within 8 min. The floc strength factor of PACl, Al(2)(SO(4))(3), PFS, FeCl(3) and TiCl(4) was 34, 30, 29, 26 and 29, respectively, while the floc recovery factor of the TiCl(4) coagulant was the lowest. Based on the results of the above study, it is concluded that the TiCl(4) flocculation can reduce the hydraulic retention time of slow and rapid mixing, however, careful handling of sludge is required due to the low recoverability of the aggregated floc. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Post-treatment of sanitary landfill leachate by coagulation-flocculation using chitosan as primary coagulant.

    PubMed

    Nascimento, Inara Oliveira do Carmo; Guedes, Ana Rosa Pinto; Perelo, Louisa Wessels; Queiroz, Luciano Matos

    2016-01-01

    Chitosan was chosen as an alternative primary coagulant in a complementary coagulation-flocculation treatment of sanitary landfill leachate with the aim of removing recalcitrant organic matter. In order to optimize the process conditions, central composite design and response surface methodology were applied. To evaluate the performance of the process using chitosan, we also carried out tests with aluminium sulphate (Al(2) (SO(4))(3).14 H(2)O) as coagulant. In addition, acute toxicity tests were carried using the duckweed Lemna minor and the guppy fish Poecilia reticulata as test organisms. The analytic hierarchy process was employed for selecting the most appropriate coagulant. Mean values of true colour removal efficiency of 80% and turbidity removal efficiency of 91.4% were reached at chitosan dosages of 960 mg L(-1) at pH 8.5. The acute toxicity tests showed that organisms were sensitive to all samples, mainly after coagulation-flocculation using chitosan. CE(50) for L. minor was not determined because there was no inhibition of the average growth rate and biomass production; LC(50) for P. reticulata was 23% (v v(-1)). Multi-criteria analysis showed that alum was the most appropriate coagulant. Therefore, chitosan as primary coagulant was not considered to be a viable alternative in the post-treatment of landfill leachate.

  5. Coagulation monitoring: current techniques and clinical use of viscoelastic point-of-care coagulation devices.

    PubMed

    Ganter, Michael T; Hofer, Christoph K

    2008-05-01

    Perioperative monitoring of blood coagulation is critical to better understand causes of hemorrhage, to guide hemostatic therapies, and to predict the risk of bleeding during the consecutive anesthetic or surgical procedures. Point-of-care (POC) coagulation monitoring devices assessing the viscoelastic properties of whole blood, i.e., thrombelastography, rotation thrombelastometry, and Sonoclot analysis, may overcome several limitations of routine coagulation tests in the perioperative setting. The advantage of these techniques is that they have the potential to measure the clotting process, starting with fibrin formation and continue through to clot retraction and fibrinolysis at the bedside, with minimal delays. Furthermore, the coagulation status of patients is assessed in whole blood, allowing the plasmatic coagulation system to interact with platelets and red cells, and thereby providing useful additional information on platelet function. Viscoelastic POC coagulation devices are increasingly being used in clinical practice, especially in the management of patients undergoing cardiac and liver surgery. Furthermore, they provide useful information in a large variety of clinical scenarios, e.g., massive hemorrhage, assessment of hypo- and hypercoagulable states, guiding pro- and anticoagulant therapies, and in diagnosing of a surgical bleeding. A surgical etiology of bleeding has to be considered when viscoelastic test results are normal. In summary, viscoelastic POC coagulation devices may help identify the cause of bleeding and guide pro- and anticoagulant therapies. To ensure optimal accuracy and performance, standardized procedures for blood sampling and handling, strict quality controls and trained personnel are required.

  6. Development of the selective coagulation process

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.

    1991-01-01

    The aim of this project is to develop an economical method for producing low-sulfur and low-ash coals using the selective hydrophobic coagulation (SHC) process. This work has been divided into three tasks: (1) project planning and sample acquisition; (2) studies of the fundamental mechanism(s) of the selective coagulation process and the parameters that affect the process of separating coal from both the ash-forming minerals and pyritic sulfur; and (3) bench-scale process development test work to establish the best possible method(s) of separating the hydrophobic and coagula from the dispersed mineral matter.

  7. Computer-assisted interstitial laser coagulation for BPH

    NASA Astrophysics Data System (ADS)

    Ho, Gideon; Barrett, Adrian R. W.; Ng, Wan S.; Lim, Liam G.; Cheng, Wai S.

    2001-06-01

    Interstitial laser thermotherapy is a minimally invasive surgical procedure that utilizes laser to coagulate and treat benign prostatic hyperplasia. This study explores the use of a computer-assisted interstitial laser coagulation system to aid surgeons in performing this procedure.

  8. Nanoparticle coagulation in fractionally charged and charge fluctuating dusty plasmas

    SciTech Connect

    Nunomura, Shota; Kondo, Michio; Shiratani, Masaharu; Koga, Kazunori; Watanabe, Yukio

    2008-08-15

    The kinetics of nanoparticle coagulation has been studied in fractionally charged and charge fluctuating dusty plasmas. The coagulation occurs when the mutual collision frequency among nanoparticles exceeds their charging and decharging/neutralization frequency. Interestingly, the coagulation is suppressed while a fraction (several percent) of nanoparticles are negatively charged in a plasma, in which stochastic charging plays an important role. A model is developed to predict a phase diagram of the coagulation and its suppression.

  9. Coagulation removal of humic acid-stabilized carbon nanotubes from water by PACl: influences of hydraulic condition and water chemistry.

    PubMed

    Ma, Si; Liu, Changli; Yang, Kun; Lin, Daohui

    2012-11-15

    Discharged carbon nanotubes (CNTs) can adsorb the widely-distributed humic acid (HA) in aquatic environments and thus be stabilized. HA-stabilized CNTs can find their way into and challenge the potable water treatment system. This study investigated the efficiency of coagulation and sedimentation techniques in the removal of the HA-stabilized multi-walled carbon nanotubes (MWCNTs) using polyaluminum chloride (PACl) as a coagulant, with a focus on the effects of hydraulic conditions and water chemistry. Stirring speeds in the mixing and reacting stages were gradually changed to examine the effect of the hydraulic conditions on the removal rate. The stirring speed in the reacting stage affected floc formation and thereby had a greater impact on the removal rate than the stirring speed in the mixing stage. Water chemistry factors such as pH and ionic strength had a significant effect on the stability of MWCNT suspension and the removal efficiency. Low pH (4-7) was favorable for saving the coagulant and maintaining high removal efficiency. High ionic strength facilitated the destabilization of the HA-stabilized MWCNTs and thereby lowered the required PACl dosage for the coagulation. However, excessively high ionic strength (higher than the critical coagulation concentration) decreased the maximum removal rate, probably by inhibiting ionic activity of PACl hydrolyzate in water. These results are expected to shed light on the potential improvement of coagulation removal of aqueous stabilized MWCNTs in water treatment systems.

  10. Toward a better understanding of coagulation for dissolved organic nitrogen using polymeric zinc-iron-phosphate coagulant.

    PubMed

    Zhu, Guocheng; Wang, Qian; Yin, Jun; Li, Zhongwu; Zhang, Peng; Ren, Bozhi; Fan, Gongduan; Wan, Peng

    2016-09-01

    The increase of agricultural related activities and the lack of effective waste control has led to an increase of organic nitrogen in water. The development of coagulants to effectively remove dissolved organic nitrogen (DON) is a high priority in the water treatment industry. We developed a polymeric zinc-iron-phosphate (ZnFeP) coagulant and investigated its coagulation effect on DON removal. Optimum coagulant for coagulation for DON and TDN removals was characterized by the dense convex-concave packing structure differing from other zinc-based coagulant, polycrystalline structure and high content colloidal species, which could account up to 87% of the total colloidal species. Coagulation experiments showed the DON removal rate to vary greatly depending on principal components and their interaction with metals, phosphate and hydroxyl. DON removal efficiency increased with the increase of colloidal species. The coagulation was also dependent on coagulant dosage and water quality parameters: Coagulation efficiency increased with coagulant dosage in the investigated range of 1-16 mg/l, and a pH of 6 was found to be superior for the coagulation. DON removal efficiency was also higher than and linearly correlated with total dissolved nitrogen (TDN) removal, which implies that an effective coagulation for TDN is also effective for DON. The findings in this study indicate that coagulation of DON is largely influenced by coagulant composition and species. We also found the removal of DON by our newly developed polymeric ZnFeP coagulant to be effective. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Development of the selective hydrophobic coagulation process

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.

    1992-01-01

    A novel technique for selectively coagulating and separating coal from dispersed mineral matter has been developed at Virginia Tech. The process, Selective Hydrophobic Coagulation (SHC), has been studied since 1986 under the sponsorship of the US Department of Energy. The SHC process differs from oil agglomeration, shear or polymer flocculation, and electrolytic coagulation processes in that it does not require reagents or additives to induce the formation of coagula. In most cases, simple pH control is all that is required to (i) induce the coagulation of coal particles and (ii) effectively disperse particles of mineral matter. If the coal is oxidized, a small dosage of reagents can be used to enhance the process. The technical work program was initiated on July 1, 1992. Force-distance curves were generated for DDOA Br-coated mica surfaces in water and used to calculate hydrophobicity constants and decay lengths for this system; and a new device for the measurement of water contact angles, similar to the Wilhelmy plate balance, has been built 225 kg samples of Pittsburgh No. 8 and Elkhom No. 3 seam coals were obtained; a static mixer test facility for the study of coagula growth was set up and was undergoing shakedown tests at the end of the quarter; a bench-scale lamella thickener was being constructed; and preliminary coagula/ mineral separation tests were being conducted in a bench-scale continuous drum filter.

  12. Development of the Selective Hydrophobic Coagulation process

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.

    1992-01-01

    A novel technique for selectively coagulating and separating coal from dispersed mineral matter has been developed at Virginia Tech. The process, Selective Hydrophobic Coagulation (SHC), has been studied since 1986 under the sponsorship of the US Department of Energy (Contracts AC22-86PC91221 and AC22-90PC90174). The SHC process differs from oil agglomeration, shear or polymer flocculation, and electrolytic coagulation processes in that it does not require reagents or additives to induce the formation of coagula. In most cases, simple pH control is all that is required to (1) induce the coagulation of coal particles and (2) effectively disperse particles of mineral matter. If the coal is oxidized, a small dosage of reagents can be used to enhance the process. During the quarter, the Anutech Mark IV surface force apparatus was used to generate surface force-distance data for the mica/dodecylamine hydrochloride system (Task 2.1.1). Work to characterize the hydrophobicity of this system and the mica/DDOA[sup [minus

  13. 21 CFR 864.5400 - Coagulation instrument.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Coagulation instrument. 864.5400 Section 864.5400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated Hematology Devices §...

  14. Disseminated intravascular coagulation with Fusobacterium necrophorum septicaemia.

    PubMed Central

    Potter, M. N.; Drysdale, H. C.; Price, P. A.; Buck, A. C.

    1988-01-01

    A 23 year old woman died within six hours of admission from acute disseminated intravascular coagulation. Fusobacterium necrophorum, a Gram negative anaerobic organism, was isolated as a single pathogen from the blood cultures. This association has not previously been reported. PMID:3174529

  15. Establishing reference intervals in the coagulation laboratory.

    PubMed

    Castellone, D D

    2017-05-01

    Obtaining a reference interval (RI) is a challenge for any laboratory and becomes more complicated in the coagulation laboratory due to testing on samples with limited stability on reagents that are poorly standardized. Reference intervals are required to be able to evaluate results in relation to a patients' hemostatic disorder. This becomes one of the most important tasks conducted in the coagulation laboratory. However, many laboratories lack the time, finances and in many cases the expertise to conduct this study. Many RI are obtained from package inserts, or from publications written by experts in lieu of laboratories conducting their own studies. An overview of validating reference intervals and options for verifying or transference of reference intervals is discussed. Based on the confidence interval and the acceptability of risk laboratories are willing to accept, coagulation laboratories have options to conduct robust studies for their RI. Data mining or global reference studies may help to provide data for age specific ranges. Pre-analytical variables and selection of healthy subjects have the largest impact on coagulation testing outcomes and need to be well controlled during the establishment of reference intervals. Laboratories have options in lieu of conducting a full validation on how to verify RI based on smaller RI studies or transference of RI after determining compatibility of the original RI study. © 2017 John Wiley & Sons Ltd.

  16. Milestones and perspectives in coagulation and hemostasis.

    PubMed

    Lippi, Giuseppe; Favaloro, Emmanuel J; Franchini, Massimo; Guidi, Gian Cesare

    2009-02-01

    Hemostasis is traditionally defined as the physiologic process whereby bleeding is antagonized and possibly stopped to minimize blood loss. The first medical description of the clinical and inherited features of hemostasis can be dated back more than 1000 years, when Abu al-Qasim Khalaf ibn 'Abbas al-Andalusi al-Zahrawi' medical treatise provided some initial insights into this puzzling process. Since then, continuous and revolutionary scientific developments have contributed to decoding several aspects of this intricate but essential physiologic phenomenon, providing a reliable model to explain the leading mechanisms involved. Although the point at which bleeding stops is commonly referred to as "coagulation," blood coagulation is actually only one part of a two-part hemostatic process that develops through sequential steps referred to as primary and secondary hemostasis. Throughout its activation and development, the coagulation cascade is strictly regulated by a series of natural inhibitors, which prevent unnecessary and excessive clotting. The aim of this article is to provide a concise overview of the major discoveries and past and current perspectives in coagulation and hemostasis.

  17. 21 CFR 864.5400 - Coagulation instrument.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Coagulation instrument. 864.5400 Section 864.5400 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated Hematology Devices §...

  18. Roles for vitamin K beyond coagulation

    USDA-ARS?s Scientific Manuscript database

    Recent interest in vitamin K has been motivated by evidence of physiological roles beyond that of coagulation. Vitamin K and vitamin K-dependent proteins may be involved in regulation of calcification, energy metabolism, and inflammation. However, the evidence for many of these proposed roles in the...

  19. Development of the selective coagulation process

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.

    1991-01-01

    The overall objective of this project is to develop an economical method of producing low-ash and low-sulfur coals using the selective coagulation process. The work is subdivided into three tasks: (1) Project Planning, (2) Establish the fundamental mechanism of the selective coagulation process and determine the parameters that affect the process of separating coal from both the ash-forming minerals and pyritic sulfur, and (3) Conduct bench-scale process development testwork to establish the best possible method of separating the coagula from the dispersed mineral matter. The effect of pH on the energy of particle/bubble detachment has been measured with a single point surface force apparatus (Task 2.1); bench-scale coagulation experiments, coupled with contact angle and zeta potential measurements, are being used to determine hydrophobic interaction parameters for a Pittsburgh No. 8 coal sample (Task 2.2); and a population balance model of the hydrophobic coagulation process is under development (Task 2.3). A sample of Pittsburgh No. 8 coal has been received and is currently being characterized (Tasks 3.1 3.2), and the mixer required for Task 3.3 was designed and constructed. 4 refs., 7 figs.

  20. Blood coagulation: hemostasis and thrombin regulation.

    PubMed

    Tanaka, Kenichi A; Key, Nigel S; Levy, Jerrold H

    2009-05-01

    Perioperative bleeding is a major challenge particularly because of increasing clinical use of potent antithrombotic drugs. Understanding current concepts of coagulation is important in determining the preoperative bleeding risk of patients, and in managing hemostatic therapy perioperatively. The serine protease thrombin plays pivotal roles in the activation of additional serine protease zymogens (inactive enzymatic precursors), cofactors, and cell-surface receptors. Thrombin generation is closely regulated to locally achieve rapid hemostasis after injury without causing uncontrolled systemic thrombosis. During surgery, there are major disturbances in coagulation and inflammatory systems because of hemorrhage/hemodilution, blood transfusion, and surgical stresses. Postoperative bleeding often requires allogeneic blood transfusions, which support thrombin generation and hemostasis. However, procoagulant activity and inflammation are increased postoperatively; thus, antithrombotic therapy may be required to prevent perioperative thrombotic complications. There have been significant advances in the management of perioperative hemostasis and thrombosis because of the introduction of novel hemostatic and antithrombotic drugs. However, a limitation of current treatment is that conventional clotting tests do not reflect the entire physiological processes of coagulation making optimal pharmacologic therapy difficult. Understanding the in vivo regulatory mechanisms and pharmacologic modulation of thrombin generation may help control bleeding without potentially increasing prothrombotic risks. In this review, we focus on the regulatory mechanisms of hemostasis and thrombin generation using multiple, simplified models of coagulation.

  1. Point of Care Assessment of Coagulation.

    PubMed

    Hyatt, Clare E; Brainard, Benjamin M

    2016-03-01

    Disorders of hemostasis can be difficult to fully elucidate but can severely affect patient outcome. The optimal therapy for coagulopathies is also not always clear. Point of care (POC) testing in veterinary medicine can assist in the diagnosis of hemostatic disorders and also direct treatment. Advantages of POC testing include rapid turnaround times, ease of use, and proximity to the patient. Disadvantages include differences in analytic performance compared with reference laboratory devices, the potential for operator error, and limited test options per device. Conventional coagulation tests such as prothrombin time, activated partial thromboplastin time, and activated clotting time can be measured by POC devices and can accurately diagnose hypocoagulability, but they cannot detect hypercoagulability or disorders of fibrinolysis. Viscoelastic POC coagulation testing more accurately evaluates in vivo coagulation, and can detect hypocoagulability, hypercoagulability, and alterations in fibrinolysis. POC platelet function testing methodologies can detect platelet adhesion abnormalities including von Willebrand disease, and can be used to monitor the efficacy of antiplatelet drugs. It is unlikely that a single test would be ideal for assessing the complete coagulation status of all patients; therefore, the ideal combination of tests for a specific patient needs to be determined based on an understanding of the underlying disease, and protocols must be standardized to minimize interoperator and interinstitutional variability. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Different Recovery Profiles of Coagulation Factors, Thrombin Generation, and Coagulation Function After Hemorrhagic Shock in Pigs

    DTIC Science & Technology

    2012-06-06

    Different recovery profiles of coagulation factors, thrombin generation, and coagulation function after hemorrhagic shock in pigs Wenjun Z. Martini ...Defense. Address for reprints: Wenjun Z. Martini , PhD, The US Army Institute of Surgical Research, 3698 Chambers Pass, Ft. Sam Houston, San Antonio, TX...ELEMENT NUMBER 6. AUTHOR(S) Martini W. Z., Cortez D. S., Dubick M. A., Blackbourne L. H., 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7

  3. Novel Ion-Exchange Coagulants Remove More Low Molecular Weight Organics than Traditional Coagulants.

    PubMed

    Zhao, Huazhang; Wang, Lei; Hanigan, David; Westerhoff, Paul; Ni, Jinren

    2016-04-05

    Low molecular weight (MW) charged organic matter is poorly removed by conventional coagulants but contributes to disinfection byproduct formation during chlorination of drinking waters. We hypothesized that CIEX, a new Al-based hybrid coagulant with ion-exchange functional groups, would be new mechanistic approach to remove low MW organic matter during coagulation and would perform better than polyaluminum chloride (PACl) or metal-salt based coagulants. We measured coagulation performance using dissolved organic carbon (DOC) in a high hardness surface water. CIEX achieved excellent turbidity removal and removed 20% to 46% more DOC than FeCl3, Al2(SO4)3, or PACl, depending on dose. The improved DOC removal was attributable to better removal of low MW organic matter (<2 kDa). We further studied removal mechanisms in a model water containing a low MW organic acid (salicylic acid (SA)). CIEX achieved high removal of organic acids (>90% of SA) independent of pH, whereas removal by metal salts was lower (<15%) and was strongly pH dependent. CIEX ion-exchange capability is facilitated by its covalently bound quaternary ammonium group, which conventional coagulants lack. Plus, unlike other cationic polymers that react with chloramines to form N-nitrosodimethylamine (NDMA), CIEX has a low molar yield (9.3 × 10(-7) mol NDMA per mol CIEX-N).

  4. Dynamic analysis of coagulation of low turbidity water sources using Al- and Fe-based coagulants.

    PubMed

    Ebie, K; Kawaguchi, T; Yamaguchi, D

    2006-01-01

    The direct filtration system is widely used in the treatment of source waters with low and stable turbidity. We have previously indicated the importance of optimizing agitation strength GR and time TR in rapid mixing tanks in order to decrease filter head loss and treated water turbidity in direct filtration. In the present study, we employ a batch-type coagulation experimental apparatus that incorporates a high-sensitivity particle counter, where the particulate concentrations are measured continuously after injection of coagulant, in order to clarify the fundamental coagulation and microfloc formation dynamics. Specifically, it is shown that, after injection of the coagulant, coagulation and microfloc formation occur through distinct periods: an agglomeration preparation period, followed by an agglomeration progression period, and then finally an agglomeration stabilization period, and that optimization of the GR value is the most important consideration, although both the coagulant concentration and GR influence the time at which agglomeration begins in the preparatory period, the time at which agglomeration stabilizes after the progression period, and the concentration of initial particles with diameters of 1-3 microm at completion of agglomeration.

  5. Enhanced coagulation for improving coagulation performance and reducing residual aluminum combining polyaluminum chloride with diatomite.

    PubMed

    Hu, Wenchao; Wu, Chunde

    2016-01-01

    The feasibility of using enhanced coagulation, which combined polyaluminum chloride (PAC) with diatomite for improving coagulation performance and reducing the residual aluminum (Al), was discussed. The effects of PAC and diatomite dosage on the coagulation performance and residual Al were mainly investigated. Results demonstrated that the removal efficiencies of turbidity, dissolved organic carbon (DOC), and UV254 were significantly improved by the enhanced coagulation, compared with PAC coagulation alone. Meaningfully, the five forms of residual Al (total Al (TAl), total dissolved Al (TDAl), dissolved organic Al (DOAl), dissolved monomeric Al (DMAl), and dissolved organic monomeric Al (DOMAl)) all had different degrees of reduction in the presence of diatomite and achieved the lowest concentrations (0.185, 0.06, 0.053, 0.014, and 0 mg L(-1), respectively) at a PAC dose of 15 mg L(-1) and diatomite dose of 40 mg L(-1). In addition, when PAC was used as coagulant, the majority of residual Al existed in dissolved form (about 31.14-70.16%), and the content of DOMAl was small in the DMAl.

  6. Optical Thromboelastography to evaluate whole blood coagulation

    PubMed Central

    Hajjarian, Zeinab; Tripathi, Markandey M.; Nadkarni, Seemantini K.

    2015-01-01

    Measurement of blood viscoelasticity during clotting provides a direct metric of haemostatic conditions. Therefore, technologies that quantify blood viscoelasticity at the point-of-care are invaluable for diagnosing coagulopathies. We present a new approach, Optical Thromboelastography (OTEG) that measures the viscoelastic properties of coagulating blood by evaluating temporal laser speckle fluctuations, reflected from a few blood drops. During coagulation, platelet-fibrin clot formation restricts the mean square displacements (MSD) of scatterers and decelerates speckle fluctuations. Cross-correlation analysis of speckle frames provides the speckle intensity temporal autocorrelation, g2(t), from which MSD is deduced and the viscoelastic modulus of blood is estimated. Our results demonstrate a close correspondence between blood viscoelasticity evaluated by OTEG and mechanical rheometry. Spatio-temporal speckle analyses yield 2-dimensional maps of clot viscoelasticity, enabling the identification of micro-clot formation at distinct rates in normal and coagulopathic specimens. These findings confirm the unique capability of OTEG for the rapid evaluation of patients’ coagulation status and highlight the potential for point-of-care use. Spatial maps of blood viscoelasticity index, G, during clotting obtained from a normal patient (top row) and a hypo-coagulable patient with low levels of clotting factors (bottom row) at 0, 1, 14, and 30 minutes after kaolin activation. Micro-clots of significant G values appear at early times (~1 min) and continue to progress to form a large blood clot over 30 min in the normal patient. In contrast, in the hypo-coagulable sample, micro-clots of comparable G are only visible at 14 min and the extent and overall clot strength is considerably reduced compared to the normal patient even at 30 min. Scale bars are 100 μm long. These results demonstrate the high sensitivity and spatial resolution of OTEG for detecting incipient micro

  7. Unidentified coagulation disorders in post-tonsillectomy hemorrhage.

    PubMed

    Windfuhr, Jochen P; Chen, Yue-Shih; Remmert, Stephan

    2004-01-01

    We conducted a retrospective study of 6,966 patients who had undergone tonsillectomy or adenotonsillectomy to evaluate the incidence and clinical features of previously unidentified coagulation disorders in patients who experienced postoperative hemorrhage (n = 201). We found that post-tonsillectomy hemorrhage secondary to unidentified coagulation disorders is extremely rare. However, normal coagulation values and an insignificant history do not rule out coagulation disorders. If diffuse, persistent, and bilateral bleeding is not related to arterial hypertension, dissection technique, or local infection, a rapid and detailed analysis of coagulation factors should be considered.

  8. MF/UF performance with and without coagulation

    SciTech Connect

    Robert, C.; Taylor, J.S.; Reiss, C.R.

    1999-07-01

    Although size-exclusion membrane processes produce superior water quality relative to conventional surface water treatment, fouling can significantly limit the use of these membrane processes. Coagulation can reduce organic, particulate and biological fouling, and was investigated as a pretreatment process to microfiltration (MF) and ultrafiltration (UF) membrane processes. Varying coagulants, coagulant pH and dose and variation of conventional coagulation pretreatment processes including coagulation-sedimentation-filtration (CSF), coagulation-sedimentation (CS) and in-line coagulation (ILC) for varying dose and pH were investigated. The Hillsborough River, a highly organic productive subtropical surface water in Tampa, Florida and the Maumee River, a moderately productive northern US surface water were used as water sources for this study.

  9. Application of particle-size analysis in coagulation/flocculation for reclamation of a secondary effluent.

    PubMed

    Liu, Hongbo; Sun, Liping; Wang, Yan; Xia, Siqing; Le, Linshen

    2009-01-01

    Reclaimed secondary effluent is an important alternative water resource for urban areas; the particle-size distribution approach was applied in this study for purpose of screening and evaluating treatment processes for reclamation of a secondary effluent. Two particle-size analysing technologies namely (1) the laser light scattering technology and (2) the sequential membrane filtration technology were used in this study; particulate characteristics of the secondary effluent, of the reclaimed water by coagulation and of the reclaimed water by combined coagulation/flocculation were investigated. Optimisation of coagulation and/or combined coagulation/flocculation technologies were carried out with the help of particulate analysis of priority pollutants, following which studies on turbidity removing mechanisms of both processes were discussed. Comparison studies indicated that increase of turbidity removal efficiency by flocculation happened mainly in the particulate range of 0.2-0.3 microm and 5-8 microm; flocculation did not help or even slightly deteriorated turbidity removal of particles whose sizes are smaller than 0.2 microm and/or in the range of 0.3-5 microm.

  10. Coagulation activation by MC28 fibrosarcoma cells facilitates lung tumor formation.

    PubMed

    Amirkhosravi, M; Francis, J L

    1995-01-01

    Tumor cells interact with the hemostatic system in various ways and may thus influence malignant growth and spread. MC28 fibrosarcoma cells possess a potent procoagulant activity (PCA) and form lung tumors following intravenous injection. The aim of this work was to study the relationship between PCA, intravascular coagulation and lung seeding in the MC28 model. MC28 cells were injected into control, warfarinized and heparinized hooded Lister rats. Coagulation changes were monitored by thromboelastography (TEG) and Sonoclot analysis (SA), lung fibrin formation by light and electron microscopy, tumor seeding by macroscopic counting and tumor cell and platelet deposition in the lungs by radiolabelling. PCA was measured by chromogenic assay. MC28 PCA was characterized as a tissue factor-factor VIIa complex that probably arose during cell culture or disaggregation of solid tumors. Injection of tumor cells caused marked coagulopathy and was rapidly (within 30 min) followed by fibrin deposition in the lungs and accumulation of radiolabelled platelets. Heparin and warfarin significantly reduced lung seeding (p < 0.001) and reduced retention of radiolabelled tumor cells in the pulmonary circulation (p < 0.01). Inhibition of cellular PCA by prior treatment with concanavalin A markedly reduced intravascular coagulation and lung seeding. We conclude that MC28 cells cause intravascular coagulation as a direct result of their procoagulant activity. The data suggest that tumor cells form complexes with platelets and fibrin which are retained in the lungs long enough for extravasation and seeding to occur.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Laser tissue coagulation and concurrent optical coherence tomography through a double-clad fiber coupler

    PubMed Central

    Beaudette, Kathy; Baac, Hyoung Won; Madore, Wendy-Julie; Villiger, Martin; Godbout, Nicolas; Bouma, Brett E.; Boudoux, Caroline

    2015-01-01

    Double-clad fiber (DCF) is herein used in conjunction with a double-clad fiber coupler (DCFC) to enable simultaneous and co-registered optical coherence tomography (OCT) and laser tissue coagulation. The DCF allows a single channel fiber-optic probe to be shared: i.e. the core propagating the OCT signal while the inner cladding delivers the coagulation laser light. We herein present a novel DCFC designed and built to combine both signals within a DCF (>90% of single-mode transmission; >65% multimode coupling). Potential OCT imaging degradation mechanisms are also investigated and solutions to mitigate them are presented. The combined DCFC-based system was used to induce coagulation of an ex vivo swine esophagus allowing a real-time assessment of thermal dynamic processes. We therefore demonstrate a DCFC-based system combining OCT imaging with laser coagulation through a single fiber, thus enabling both modalities to be performed simultaneously and in a co-registered manner. Such a system enables endoscopic image-guided laser marking of superficial epithelial tissues or laser thermal therapy of epithelial lesions in pathologies such as Barrett’s esophagus. PMID:25909013

  12. Coagulative and ablative characteristics of a novel diode laser system (1470nm) for endonasal applications

    NASA Astrophysics Data System (ADS)

    Betz, C. S.; Havel, M.; Janda, P.; Leunig, A.; Sroka, R.

    2008-02-01

    Introduction: Being practical, efficient and inexpensive, fibre guided diode laser systems are preferable over others for endonasal applications. A new medical 1470 nm diode laser system is expected to offer good ablative and coagulative tissue effects. Methods: The new 1470 nm diode laser system was compared to a conventional 940 nm system with regards to laser tissue effects (ablation, coagulation, carbonization zones) in an ex vivo setup using fresh liver and muscle tissue. The laser fibres were fixed to a computer controlled stepper motor, and the light was applied using comparable power settings and a reproducible procedure under constant conditions. Clinical efficacy and postoperative morbidity was evaluated in two groups of 10 patients undergoing laser coagulation therapy of hyperplastic nasal turbinates. Results: In the experimental setup, the 1470 nm laser diode system proved to be more efficient in inducing tissue effects with an energy factor of 2-3 for highly perfused hepatic tissue to 30 for muscular tissue. In the clinical case series, the higher efficacy of the 1470 nm diode laser system led to reduced energy settings as compared to the conventional system with comparable clinical results. Postoperative crusting was less pronounced in the 1470 nm laser group. Conclusion: The 1470 nm diode laser system offers a highly efficient alternative to conventional diode laser systems for the coagulation of hyperplastic nasal turbinates. According to the experimental results it can be furthermore expected that it disposes of an excellent surgical potential with regards to its cutting abilities.

  13. Laser tissue coagulation and concurrent optical coherence tomography through a double-clad fiber coupler.

    PubMed

    Beaudette, Kathy; Baac, Hyoung Won; Madore, Wendy-Julie; Villiger, Martin; Godbout, Nicolas; Bouma, Brett E; Boudoux, Caroline

    2015-04-01

    Double-clad fiber (DCF) is herein used in conjunction with a double-clad fiber coupler (DCFC) to enable simultaneous and co-registered optical coherence tomography (OCT) and laser tissue coagulation. The DCF allows a single channel fiber-optic probe to be shared: i.e. the core propagating the OCT signal while the inner cladding delivers the coagulation laser light. We herein present a novel DCFC designed and built to combine both signals within a DCF (>90% of single-mode transmission; >65% multimode coupling). Potential OCT imaging degradation mechanisms are also investigated and solutions to mitigate them are presented. The combined DCFC-based system was used to induce coagulation of an ex vivo swine esophagus allowing a real-time assessment of thermal dynamic processes. We therefore demonstrate a DCFC-based system combining OCT imaging with laser coagulation through a single fiber, thus enabling both modalities to be performed simultaneously and in a co-registered manner. Such a system enables endoscopic image-guided laser marking of superficial epithelial tissues or laser thermal therapy of epithelial lesions in pathologies such as Barrett's esophagus.

  14. Magnetic Resonance Mediated Radio Frequency Coagulation for Vascular Repair

    NASA Astrophysics Data System (ADS)

    Zhao, Ming

    Purpose. Magnetic Resonance Mediated Radiofrequency Coagulation employs the RF heating effect of MRI scanning to coagulate biomaterials for repair of vascular defects. Coagulation of a protein biomaterial by MR-induced RF heating is a novel means to effect repair of defects such as aneurysms or arteriovenous malformations. Our novel method is to coagulate a thermosetting material (such as egg white, which can be used for investigating heat coagulation behavior and MR relaxation properties) delivered endovascularly by catheter and coagulated by RF-induced heating of an intracatheter resonant wire antenna in the scanner. Methods. Experiments were performed on a Siemens 1.5 T MRI scanner and a Bruker 14T NMR spectrometer. Egg white was brought to equilibrium at seven temperatures (20, 30, 40, 50, 60, 70 and 37 °C) in sequence. Measurement of the water spin-lattice relaxation time Ti, spin-spin relaxation time T2, spin-lattice relaxation time in the rotating frame T1p, or full width at half maximum of the MT spectrum were performed at each temperature. Relaxation parameters of raw egg white and egg white after coagulation at 70 °C were measured in the scanner at 20 °C to determine optimum inversion time, echo time and offset frequency for good image contrast between coagulated and uncoagulated protein. Finally, coagulation of egg white within a glass aneurysm phantom by RF heating in the scanner was performed to demonstrate the MR coagulation methodology and the ability to achieve image contrast between coagulated and uncoagulated biomaterial. Results. Water T2, T1p and MT gave the most definitive indication of the change from uncoagulated at low temperature to fully coagulated at 60 °C, while water T1 showed only the expected gradual increase with temperature, and no response to coagulation. MT weighted imaging is expected to be the optimum method to establish the coagulation condition of the biomaterial.

  15. The coagulation characteristics of humic acid by using acid-soluble chitosan, water-soluble chitosan, and chitosan coagulant mixtures.

    PubMed

    Chen, Chih-Yu; Wu, Chung-Yu; Chung, Ying-Chien

    2015-01-01

    Chitosan is a potential substitute for traditional aluminium salts in water treatment systems. This study compared the characteristics of humic acid (HA) removal by using acid-soluble chitosan, water-soluble chitosan, and coagulant mixtures of chitosan with aluminium sulphate (alum) or polyaluminium chloride (PACl). In addition, we evaluated their respective coagulation efficiencies at various coagulant concentrations, pH values, turbidities, and hardness levels. Furthermore, we determined the size and settling velocity of flocs formed by these coagulants to identify the major factors affecting HA coagulation. The coagulation efficiency of acid- and water-soluble chitosan for 15 mg/l of HA was 74.4% and 87.5%, respectively. The optimal coagulation range of water-soluble chitosan (9-20 mg/l) was broader than that of acid-soluble chitosan (4-8 mg/l). Notably, acid-soluble chitosan/PACl and water-soluble chitosan/alum coagulant mixtures exhibited a higher coagulation efficiency for HA than for PACl or alum alone. Furthermore, these coagulant mixtures yielded an acceptable floc settling velocity and savings in both installation and operational expenses. Based on these results, we confidently assert that coagulant mixtures with a 1:1 mass ratio of acid-soluble chitosan/PACl and water-soluble chitosan/alum provide a substantially more cost-effective alternative to using chitosan alone for removing HA from water.

  16. Casting uniform ceramics with direct coagulation

    SciTech Connect

    Graule, T.J.; Baader, F.H.; Gauckler, L.J.

    1995-06-01

    Today complex-shaped ceramic parts are mass fabricated by many different methods, two of which are slip casting and injection molding. The selection of the appropriate technique is governed by the geometric shape, the number of pieces to be manufactured, and the chemistry of the ceramic. Both slip casting and injection molding introduce imperfections in the green part, which lead to inhomogeneous microstructures in the sintered parts. A new fabrication method, direct coagulation casting (DCC), may be suitable for the mass production of complex ceramic parts with high strength and reliability. In DCC, an aqueous suspension is coagulated by a change in pH or an increase in ionic strength after casting, producing a rigid green body. The use of DCC can avoid most of the limitations of conventional shaping techniques, and it can be applied to a large variety of ceramic powders, sols, and polymers, alone or in combination.

  17. Coagulation of dust particles in a plasma

    SciTech Connect

    Horanyi, M.; Goertz, C.K. Iowa Univ., Iowa City )

    1990-09-01

    The electrostatic charge of small dust grains in a plasma in which the temperature varies in time is discussed, pointing out that secondary electron emission might introduce charge separation. If the sign of the charge on small grains is opposite to that on big ones, enhanced coagulation can occur which will affect the size distribution of grains in a plasma. Two scenarios where this process might be relevant are considered: a hot plasma environment with temperature fluctuations and a cold plasma environment with transient heating events. The importance of the enhanced coagulation is uncertain, because the plasma parameters in grain-producing environments such as a molecular cloud or a protoplanetary disk are not known. It is possible, however, that this process is the most efficient mechanism for the growth of grains in the size range of 0.1-500 microns. 9 refs.

  18. Coagulation of dust particles in a plasma

    NASA Technical Reports Server (NTRS)

    Horanyi, M.; Goertz, C. K.

    1990-01-01

    The electrostatic charge of small dust grains in a plasma in which the temperature varies in time is discussed, pointing out that secondary electron emission might introduce charge separation. If the sign of the charge on small grains is opposite to that on big ones, enhanced coagulation can occur which will affect the size distribution of grains in a plasma. Two scenarios where this process might be relevant are considered: a hot plasma environment with temperature fluctuations and a cold plasma environment with transient heating events. The importance of the enhanced coagulation is uncertain, because the plasma parameters in grain-producing environments such as a molecular cloud or a protoplanetary disk are not known. It is possible, however, that this process is the most efficient mechanism for the growth of grains in the size range of 0.1-500 microns.

  19. Poly(γ-glutamic acid), coagulation? Anticoagulation?

    PubMed

    Xu, Tingting; Peng, Fang; Zhang, Tao; Chi, Bo; Xu, Hong; Mao, Chun; Feng, Shuaihui

    2016-11-01

    Poly(γ-glutamic acid) (γ-PGA) powder was usually used as hemostatic agent because of its excellent physical properties of water-absorption and water-locking. However, if γ-PGA absorbs enough water, how about its blood compatibility? Here, the other side of the coin was investigated. The anticoagulant properties of γ-PGA were characterized by in vitro coagulation tests, hemolytic assay, platelet adhesion, and platelet activation. Moreover, cytotoxicity experiments of γ-PGA were also carried out by MTT assay. Results indicated that the sufficient water-absorbed γ-PGA has good anticoagulant property and non-cytotoxicity. It means γ-PGA has good anticoagulant property, non-cytotoxicity. If γ-PGA has absorbed enough water, it can be used as an anticoagulation biomaterial. With double effects (coagulation and anticoagulation), the γ-PGA with desirable bioproperties can be readily tailored to cater to various biomedical applications.

  20. Blood coagulation disorders in septic patients.

    PubMed

    Knoebl, Paul

    2010-03-01

    Host defense and blood coagulation are tightly connected and interacting systems, necessary for the integrity of an organism. Complex mechanisms regulate the intensity of a host response to invading pathogens or other potentially dangerous situations. Under regular conditions, this response is limited in time and located to the site of injury. Sometimes, however, systemic host response is overwhelming and disproportional and causes damage, not cure. Dependent on the genetical predisposition of the host, its current immunocompetence, or the type of injury, the reaction leads to the clinical picture of the different degrees of sepsis. Septic organ dysfunction is caused by intravascular fibrin deposition as a result of coagulation activation, anticoagulant breakdown, and shut down of fibrinolysis. This article describes the major pathophysiologic reactions in these situations and presents www.SepDIC.eu, an online tool on sepsis and associated coagulopathy.

  1. Coagulation of dust particles in a plasma

    NASA Technical Reports Server (NTRS)

    Horanyi, M.; Goertz, C. K.

    1990-01-01

    The electrostatic charge of small dust grains in a plasma in which the temperature varies in time is discussed, pointing out that secondary electron emission might introduce charge separation. If the sign of the charge on small grains is opposite to that on big ones, enhanced coagulation can occur which will affect the size distribution of grains in a plasma. Two scenarios where this process might be relevant are considered: a hot plasma environment with temperature fluctuations and a cold plasma environment with transient heating events. The importance of the enhanced coagulation is uncertain, because the plasma parameters in grain-producing environments such as a molecular cloud or a protoplanetary disk are not known. It is possible, however, that this process is the most efficient mechanism for the growth of grains in the size range of 0.1-500 microns.

  2. Allosteric activation of coagulation factor VIIa.

    PubMed

    Persson, Egon; Olsen, Ole Hvilsted

    2011-06-01

    Coagulation factor VIIa (FVIIa) is present at subnanomolar concentration and represents a small percentage of the total amount of FVII in the circulation. FVIIa is poised to initiate blood clotting when it encounters its pivotal cofactor tissue factor (TF) which becomes exposed to blood upon vascular rupture. The requirement for complex formation with TF in order for FVIIa to express procoagulant activity ensures thrombin and fibrin generation at the right time and place. Thus TF acts as a guardian of safety of paramount importance to blood coagulation by providing localization to the site of injury and at the same time inducing maturation of zymogen-like free FVIIa to the active cofactor-bound enzyme. This review gives an account of the accumulated knowledge about the structure, function and TF dependence of FVIIa to arrive at a plausible allosteric mechanism by which TF induces maturation of the active conformation of FVIIa.

  3. Development of the selective coagulation process

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.

    1992-07-01

    The selective hydrophobic coagulation (SHC) process is based on the recent finding that hydrophobic particles can be selectively coagulated without using traditional agglomerating agents or flocculants. The driving force for the coagulation is the attractive energy between hydrophobic surfaces, an interaction that has been overlooked in classical colloid chemistry. In most cases, selective separations can be achieved using simple pH control to disperse the mineral matter, followed by recovery of the coal coagula using techniques that take advantage of the size enlargement. In the present work, studies have been carried out to further investigate the fundamental mechanisms of the SHC process and the parameters that affect the process of separating coal from the ash-forming minerals and pyritic sulfur. Studies have included direct force measurements of the attractive interaction between model hydrophobic surfaces, in-situ measurements of the size distributions of coagula formed under a variety of operating conditions, and development of a population balance model to describe the coagulation process. An extended DLVO colloid stability model which includes a hydrophobic interaction energy term has also been developed to explain the findings obtained from the experimental studies. In addition to the fundamental studies, bench-scale process development test work has been performed to establish the best possible method of separating the coagula from dispersed mineral matter. Two types of separators, i.e., a sedimentation tank and a rotating drum screen, were examined in this study. The sedimentation tank proved to be the more efficient unit, achieving ash reductions as high as 60% in a single pass while recovering more than 90% of the combustible material. This device, which minimizes turbulence and coagula breakage, was used in subsequent test work to optimize design and operating parameters.

  4. Imaging of blood plasma coagulation at supported lipid membranes.

    PubMed

    Faxälv, Lars; Hume, Jasmin; Kasemo, Bengt; Svedhem, Sofia

    2011-12-15

    The blood coagulation system relies on lipid membrane constituents to act as regulators of the coagulation process upon vascular trauma, and in particular the 2D configuration of the lipid membranes is known to efficiently catalyze enzymatic activity of blood coagulation factors. This work demonstrates a new application of a recently developed methodology to study blood coagulation at lipid membrane interfaces with the use of imaging technology. Lipid membranes with varied net charges were formed on silica supports by systematically using different combinations of lipids where neutral phosphocholine (PC) lipids were mixed with phospholipids having either positively charged ethylphosphocholine (EPC), or negatively charged phosphatidylserine (PS) headgroups. Coagulation imaging demonstrated that negatively charged SiO(2) and membrane surfaces exposing PS (obtained from liposomes containing 30% of PS) had coagulation times which were significantly shorter than those for plain PC membranes and EPC exposing membrane surfaces (obtained from liposomes containing 30% of EPC). Coagulation times decreased non-linearly with increasing negative surface charge for lipid membranes. A threshold value for shorter coagulation times was observed below a PS content of ∼6%. We conclude that the lipid membranes on solid support studied with the imaging setup as presented in this study offers a flexible and non-expensive solution for coagulation studies at biological membranes. It will be interesting to extend the present study towards examining coagulation on more complex lipid-based model systems. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Arsenic removal from drinking water during coagulation

    SciTech Connect

    Hering, J.G.; Chen, P.Y.; Wilkie, J.A.; Elimelech, M.

    1997-08-01

    The efficiency of arsenic removal from source waters and artificial freshwaters during coagulation with ferric chloride and alum was examined in bench-scale studies. Arsenic(V) removal by either ferric chloride or alum was relatively insensitive to variations in source water composition below pH 8. At pH 8 and 9, the efficiency of arsenic(V) removal by ferric chloride was decreased in the presence of natural organic matter. The pH range for arsenic(V) removal with alum was more restricted than with ferric chloride. For source waters spiked with 20 {micro}g/L arsenic(V), final dissolved arsenic(V) concentrations in the product water of less than 2 {micro}g/L were achieved with both coagulants at neutral pH. Removal of arsenic(III) from source waters by ferric chloride was both less efficient and more strongly influenced by source water composition than removal of arsenic(V). The presence of sulfate (at pH 4 and 5) and natural organic matter (at pH 4 through 9) adversely affected the efficiency of arsenic(III) removal by ferric chloride. Arsenic(III) could not be removed from source waters by coagulation with alum.

  6. Autovalidation rates in an outpatient coagulation laboratory.

    PubMed

    Froom, P; Saffuri-Elias, E; Barak, M

    2015-10-01

    To determine the rates of autovalidation in our outpatient coagulation laboratory. We retrospectively identified all coagulation tests analyzed during the month of January 2014 from our laboratory information system (LIS) (N = 16 116), from around 800 000 active members of Clalit Health Services (a health maintenance organization). The integrated system includes a single centrifugation of all collection tubes, analyzers that rerun or reflex tests according to the test results, and a laboratory information system that sends orders to the analyzer, autovalidates test results, and automatically sends critical value results to a list for immediate physician communication. Reasons for technician validation are tests rerun for confirmation or because of analyzer errors and test results that require reflex testing. All other test results are sent automatically to the laboratory information system without the need for technician review. There were 362 test results with analyzer errors, 91 results rerun for confirmation (thrombophilia test results outside the reference interval), and 50 tests with mixing studies and reflex testing for factor XI activity levels (total = 3.1%, 503/16116), resulting in an autovalidation rate of 96.9% (95% confidence interval - 96.6-97.2%). We conclude that an integrated system can result in a high autovalidation rate in a high-volume outpatient coagulation laboratory. © 2015 John Wiley & Sons Ltd.

  7. Development of the selective coagulation process

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.

    1991-01-01

    The overall objective of this project is to develop an economical method of producing low-ash and low-sulfur coals using the selective coagulation process. Work is subdivided into three tasks: (1) project planning; (2) studies of the fundamental mechanism of the selective coagulation process and the parameters that affect the process of separating coal from both the ash-forming minerals and pyritic sulfur; and (3) bench-scale process development testwork to establish the best possible methods of separating the coagula from the dispersed mineral matter. During the second quarter, the effects of surface hydrophobicity, pH and KCI concentrations on the interaction energies of attachment and detachment have been evaluated; hydrophobic interaction parameters were determined for oxidized and unoxidized; Elkhorn No. 3 seam coal samples and then compared with calculations based on the extended DLVO theory; and work continued on the population balance model of the hydrophobic coagulation process. A sample of Elkhorn No. 3 seam coal was obtained and is currently being characterized; a particle size monitor has been received; and work has begun on enhancing the separation of coagula (Task 3.4). 14 figs.

  8. Influence of fat replacement by inulin on rheological properties, kinetics of rennet milk coagulation, and syneresis of milk gels.

    PubMed

    Arango, O; Trujillo, A J; Castillo, M

    2013-04-01

    The objective of this study was to evaluate the effect of inulin as a fat replacer on the rheological properties, coagulation kinetics, and syneresis of milk gels. A randomized factorial design, replicated 3 times, with 3 inulin concentrations (0, 3, and 6%), 2 levels of fat (<0.2 and 1.5%), and 3 coagulation temperatures (27, 32, and 37°C) was used. The coagulation process was monitored using near-infrared spectrometry, small amplitude oscillatory rheometry, and visual coagulation indexes. The syneresis was evaluated by volumetric methods. Inulin addition increased the rates of aggregation and curd firming reactions in the casein gels. The observed effect, which was more evident on the aggregation reaction, depended on the concentration of inulin and the coagulation temperature. Addition of 6% inulin reduced the clotting time by approximately 26% and the time at which the gel reached a storage modulus equal to 30 Pa by approximately 36%. The optical parameter R'max, defined as the maximum value of change in light backscatter profile/change in time (where R' = dR/dt), was used to calculate an approximation of the temperature coefficients (Q10) for milk coagulation. Increasing fat concentration induced a consistent increase in all the optical, rheological, and visual parameters studied, although the observed trend was not statistically significant. The addition of inulin at a level of 6% produced a reduction in syneresis and increased the curd yield by approximately 30%. It was concluded that the addition of inulin affects the kinetics of milk coagulation and the cutting time and, therefore, the use of inline sensors such as near-infrared spectrometry may be necessary for optimal process control. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  9. Application of the precipitation-charge neutralization model of coagulation

    SciTech Connect

    Dentel, S.K.

    1988-07-01

    A quantitative model is considered that develops predictions of suspension stability on the basis of electrokinetic characteristics of colloid material prior to and following coagulation. The model is applied in this paper to coagulation with aluminum sulfate and other aluminum salts. The effect of increasing particle surface area on coagulation is first modeled for a system containing particulate silica, but of varying size and concentration. Experimental results show a correlation of turbidity removal to attainment of near neutral zeta potential in zone 2 coagulation, and the calibrated model successfully predicts this zone. The model is then used to describe the coagulation of waters containing humic substances by considering them as small colloids with a substantial contribution to surface area in the system. Finally, it is shown that the model can be employed to describe the performance of polyaluminum coagulants as well.

  10. Blood flow and mass transfer regulation of coagulation

    PubMed Central

    Rana, Kuldeepsinh; Neeves, Keith B.

    2016-01-01

    Blood flow regulates coagulation and fibrin formation by controlling the transport, or mass transfer, of zymogens, co-factors, enzymes, and inhibitors to, from, and within a growing thrombus. The rate of mass transfer of these solutes relative to their consumption or production by coagulation reactions determines, in part, the rate of thrombin generation, fibrin deposition, and thrombi growth. Experimental studies on the influence of blood flow on specific coagulation reactions are reviewed here, along with a theoretical framework that predicts how flow influences surface-bound coagulation binding and enzymatic reactions. These flow-mediated transport mechanisms are also used to interpret the role of binding site densities and injury size on initiating coagulation and fibrin deposition. The importance of transport of coagulation proteins within the interstitial spaces of thrombi is shown to influence thrombi architecture, growth, and arrest. PMID:27133256

  11. Cellular proteins of Microcystis aeruginosa inhibiting coagulation with polyaluminum chloride.

    PubMed

    Takaara, Tomoko; Sano, Daisuke; Konno, Hiroshi; Omura, Tatsuo

    2007-04-01

    Cyanobacterial growth in semi-closed water areas such as reservoirs brings about a coagulation inhibition in a drinking water treatment system, but the inhibitory substances and mechanisms involved have yet to be elucidated. In this study, proteins having a high affinity with polyaluminum chloride (PACl) were isolated from organic substances produced by Microcystis aeruginosa with the affinity chromatography technique. Both extracellular organic matter (EOM) and cellular organic matter (COM) disturbed the flocculation of suspended kaolin with PACl, but it was likely that nonproteinous substances in EOM cause the reduction of coagulation effciency. In contrast, proteins in COM were obtained as possible inhibitory substances for the coagulation with PACl. These proteins could consume PACl in the coagulation process due to the formation of chelate complexes between these inhibitory proteins and the coagulant. The consumption of PACl by cyanobacterial proteins could be one of the important causes of the increase in coagulant demand.

  12. Coagulation of Dust Particles in Argon Plasma of RF Discharge

    SciTech Connect

    Mankelevich, Yu. A.; Olevanov, M. A.; Pal, A. F.; Rakhimova, T. V.; Ryabinkin, A. N.; Serov, A. O.; Filippov, A. V.

    2008-09-07

    The experiments on coagulation of poly-disperse particles with various size distributions injected into the argon plasma of the magnetron radio-frequency discharge are discussed. The experiments were carried out under the conditions similar to those using dusty plasma for technology applications. Within the created theory the threshold behavior of the coagulation process was explained for the first time, the estimation of the critical particle size for onset of a fast coagulation was made, and the analytical calculation of the coagulation rate of dust particles was performed. The proposed coagulation mechanism makes it possible to describe the typical features of coagulation processes observed in experiments and to explain the effects of attraction and coalescence of highly negatively charged microns size particles.

  13. The Interface between Inflammation and Coagulation in Cardiovascular Disease

    PubMed Central

    Demetz, Gabriele; Ott, Ilka

    2012-01-01

    The intimate connection between coagulation and inflammation in the pathogenesis of vascular disease has moved more and more into focus of clinical research. This paper focuses on the essential components of this interplay in the settings of cardiovascular disease and acute coronary syndrome. Tissue factor, the main initiator of the extrinsic coagulation pathway, plays a central role via causing a proinflammatory response through activation of coagulation factors and thereby initiating coagulation and downstream cellular signalling pathways. Regarding activated clotting factors II, X, and VII, protease-activated receptors provide the molecular link between coagulation and inflammation. Hereby, PAR-1 displays deleterious as well as beneficial properties. Unravelling these interrelations may help developing new strategies to ameliorate the detrimental reciprocal aggravation of inflammation and coagulation. PMID:22518344

  14. A comprehensive model for the humoral coagulation network in humans.

    PubMed

    Wajima, T; Isbister, G K; Duffull, S B

    2009-09-01

    Coagulation is an important process in hemostasis and comprises a complicated interaction of multiple enzymes and proteins. We have developed a mechanistic quantitative model of the coagulation network. The model accurately describes the time courses of coagulation factors following in vivo activation as well as in vitro blood coagulation tests of prothrombin time (PT, often reported as international normalized ratio (INR)) and activated partial thromboplastin time (aPTT). The model predicts the concentration-time and time-effect profiles of warfarin, heparins, and vitamin K in humans. The model can be applied to predict the time courses of coagulation kinetics in clinical situations (e.g., hemophilia) and for biomarker identification during drug development. The model developed in this study is the first quantitative description of the comprehensive coagulation network.

  15. Coagulation Defects in Experimental Hepatic Injury in the Dog

    PubMed Central

    Osbaldiston, G. W.; Hoffman, Marcia W.

    1971-01-01

    Alteration in activity of blood coagulation factors in dogs with acute hepatic injury caused by oral carbon tetrachloride dosing was studied. Coagulation Factors II, VII and IX were dramatically reduced within 48 hours but recovered to normal in the next five days. Because surgery is rarely performed on dogs with hepatic necrosis, the use of fresh whole blood tranfusion to improve the coagulation defect in hepatic injury was also studied. Transfusion was found to have only a temporary beneficial effect. PMID:4253461

  16. Recovery of struvite via coagulation and flocculation using natural compounds.

    PubMed

    Latifian, Maryam; Liu, Jing; Mattiasson, Bo

    2014-01-01

    One of the major setbacks of struvite recovery processes is the difficulty in harvesting struvite crystals. This study evaluates the use of different coagulants to improve precipitation of struvite (MgNH4PO4.6H20) crystals. Chitosan and poly(diallyldimethyl ammonium chloride) (Poly-DADMAC) as a coagulant-flocculent and alginate and bentonite as a coagulant aid have been examined in jar tests. Also, a continuous three-phase process, i.e., struvite crystallization, coagulation/flocculation and precipitation process, was set up for real wastewater. Addition of chitosan as the coagulant and bentonite as the coagulant aid was significantly more efficient in forming struvite flocs in comparison to Poly-DADMAC alone or with coagulant aid, which did not show any positive effect. The calculated average settling velocity of struvite with chitosan-bentonite addition in synthetic and in real wastewater increased by approximately 5.3 and 2.8 folds, respectively, compared with that of no coagulant/flocculent addition. Phosphorus recovery of over 70% was achieved by the continuous process. Findings in this study clearly confirmed the possibility of using chitosan and bentonite as an efficient coagulant-flocculent to enhance the recovery of struvite crystals.

  17. Improving the efficiency of clarifiers for coagulation treatment of water

    NASA Astrophysics Data System (ADS)

    Vinogradov, V. N.; Smirnov, B. A.; Zhadan, A. V.; Avan, V. K.

    2010-08-01

    Technological and design possibilities of improving clarifiers for coagulation treatment of water are considered. The results obtained from implementing these possibilities in real devices are presented.

  18. Innate immunity, coagulation and placenta-related adverse pregnancy outcomes.

    PubMed

    Li, Min; Huang, S Joseph

    2009-12-01

    Maternal immunity undergoes subtle adjustment in order to tolerate the semi-allogeneic embryo and maintain the host defense against potential pathogens. Concomitantly, coagulation systems change from an anti-coagulant state to a pro-coagulant state to meet the hemostatic challenge of placentation and delivery. Innate immunity and blood coagulation systems are the first line of defense to protect a host against exogenous challenges, including alloantigens and mechanical insults, and preserve the integrity of an organism. The interactions between coagulation and immune systems have been extensively studied. Immune cells play a pivotal role in the initiation of the coagulation cascade, whereas coagulation proteases display substantial immuno-modulatory effects. Upon exogenous challenges, the immune and coagulation systems are capable of potentiating each other leading to a vicious cycle. Natural killer (NK) cells, macrophages (Mphis) and dendritic cells (DCs) are three major innate immune cells that have been demonstrated to play essential roles in early pregnancy. However, immune maladaptation and hemostatic imbalance have been suggested to be responsible for adverse pregnant outcomes, such as preeclampsia (PE), miscarriage, recurrent spontaneous abortion (RSA) and intrauterine growth restriction (IUGR). In this review, we will summarize the mutual regulation between blood coagulation and innate immune systems as well as their roles in the maintenance of normal pregnancy and in the pathogenesis of adverse pregnancy outcomes.

  19. Compound bioflocculant and polyaluminum chloride in kaolin-humic acid coagulation: factors influencing coagulation performance and floc characteristics.

    PubMed

    Li, Ruihua; Gao, Baoyu; Huang, Xin; Dong, Hongyu; Li, Xiaochen; Yue, Qinyan; Wang, Yan; Li, Qian

    2014-11-01

    The objective of this study was to investigate the influence of coagulant dosage and pH on coagulation performance and floc properties using polyaluminum chloride (PAC) and compound bioflocculant (CBF) dual-coagulant in kaolin-humic acid (HA) treatment. Results showed that as PAC dosage rose, comparatively better coagulation efficiencies and floc characteristics were achieved due to stronger charge neutralization and sweeping effect. Addition of CBF could enhance coagulation performance and floc properties, including size, strength and recoverability, except fractal dimension. Solution pH had a significant effect on coagulation efficiencies and flocs formation. Under acidic condition, flocs showed higher strength and recoverability but lower fractal dimension, where charge neutralization was the foremost mechanism. More compact flocs were generated under alkaline condition due to the sweeping effect of hydrolyzed Al species. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Contact activation of blood-plasma coagulation.

    PubMed

    Vogler, Erwin A; Siedlecki, Christopher A

    2009-04-01

    This opinion identifies inconsistencies in the generally-accepted surface biophysics involved in contact activation of blood-plasma coagulation, reviews recent experimental work aimed at resolving inconsistencies, and concludes that this standard paradigm requires substantial revision to accommodate new experimental observations. Foremost among these new findings is that surface-catalyzed conversion of the blood zymogen factor XII (FXII, Hageman factor) to the enzyme FXIIa (FXII [surface] --> FXIIa, a.k.a. autoactivation) is not specific for anionic surfaces, as proposed by the standard paradigm. Furthermore, it is found that surface activation is moderated by the protein composition of the fluid phase in which FXII autoactivation occurs by what appears to be a protein-adsorption-competition effect. Both of these findings argue against the standard view that contact activation of plasma coagulation is potentiated by the assembly of activation-complex proteins (FXII, FXI, prekallikrein, and high-molecular weight kininogen) directly onto activating surfaces (procoagulants) through specific protein/surface interactions. These new findings supplement the observation that adsorption behavior of FXII and FXIIa is not remarkably different from a wide variety of other blood proteins surveyed. Similarity in adsorption properties further undermines the idea that FXII and/or FXIIa are distinguished from other blood proteins by unusual adsorption properties resulting in chemically-specific interactions with activating anionic surfaces. IMPACT STATEMENT: This review shows that the consensus biochemical mechanism of contact activation of blood-plasma coagulation that has long served as a rationale for poor hemocompatibility is an inadequate basis for surface engineering of advanced cardiovascular biomaterials.

  1. Blood Coagulation and Asthma Exacerbation in Children.

    PubMed

    Manuyakorn, Wiparat; Mairiang, Dara; Sirachainan, Nongnuch; Kadegasem, Praguywan; Kamchaisatian, Wasu; Benjaponpitak, Suwat; Chuansumrit, Ampaiwan

    2016-01-01

    Recent studies have demonstrated the activation of coagulation pathways in asthmatic airways. This study aimed to determine systemic blood coagulation during asthma exacerbation compared with the stable state in children. Pediatric patients (aged between 5 and 15 years) suffering from asthma exacerbation were enrolled. von Willebrand factor (vWF), plasminogen activator inhibitor type-1 (PAI-1), protein C, D-dimer, prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin complex (TAT), and C-reactive protein (CRP) levels were measured during asthma exacerbation and stable state. A total of 22 patients were enrolled. The median vWF, PAI-1, and CRP during asthma exacerbation were significantly higher than those of the stable state: 147.5% (interquartile range, IQR: 111.05-196.57) versus 94% (IQR: 69.72-109.62, p < 0.001), 41.9 ng/ml (IQR: 21.91-48.61) versus 26.17 ng/ml (IQR: 15.89-34.44, p < 0.03), and 4.46 mg/l (IQR: 2.15-16.23) versus 0.87 mg/l (IQR: 0.20-3.89, p < 0.015), respectively. However, the median protein C during asthma exacerbation was significantly lower than that of the stable state: 99.5% (IQR: 86.75-117) versus 113% (IQR: 94-115.25), p = 0.01. No significant difference was found between the levels of D-dimer, F1 + 2, and TAT during asthma exacerbation and stable state. Ultimately, D-dimer was positively correlated with asthma exacerbation score (R = 0.466, p = 0.027). A significant correlation was observed between vWF and CRP (R = 0.527, p = 0.012). Evidence was found of increased endothelial activation and increased PAI-1 during asthma exacerbation. This may emphasize the potential role of blood coagulation in asthma exacerbation. © 2016 S. Karger AG, Basel.

  2. Coagulation profile of liquid-state plasma.

    PubMed

    Gosselin, Robert C; Marshall, Carol; Dwyre, Denis M; Gresens, Chris; Davis, Diana; Scherer, Lynette; Taylor, Douglas

    2013-03-01

    Use of liquid plasma (LP) has been reported as early as the mid 1930s. Unlike fresh-frozen plasma (FFP), LP is maintained at 1 to 6°C for up to 40 days after collection and processing. Despite its approved use by the US Food and Drug Administration, the coagulation profile of LP is incompletely described. In this study we evaluate the coagulation profile of LP stored up to 30 days. LP was prepared by removing plasma from nonleukoreduced whole blood within 24 hours of collection. Three LP units from each ABO group were collected and stored at 1 to 6°C. Plasma aliquots were obtained at Postcollection Days 1 to 5, 10, 15, 20, 25, and 30 and then stored at -70°C. Each aliquot was tested for prothrombin time, activated partial thromboplastin time, and other coagulation and fibrinolytic factors. There was a significant decrease in Factor (F)V, FVII, FVIII, von Willebrand factor (VWF), protein S (PS) activity, and endogenous thrombin potential on Day 15 compared with Day 1. No significant difference was observed for PS antigen, D-dimer, or thrombin-antithrombin complex. At least 50% activity of all measured factors was noted on Day 15, compared to Day 1. Considerable heterogeneity was observed between the different blood groups for FVII, FVIII, and VWF. These data demonstrate that LP maintains at least 50% of factor activity and thrombin-generating capacity up to 15 days of refrigerated storage. It may be more appropriate to limit LP storage and supplement with FFP when used for management of massively bleeding patients. © 2012 American Association of Blood Banks.

  3. Research on orthogonal coagulated setting and coagulation-flotation test of tannery wastewater.

    PubMed

    Xu, Zhi; Fei, Qingzhi; Zhong, Weilei

    2009-01-01

    The treatment of the tannery wastewater was studied by orthogonal test of beaker coagulation. FeSO4 and alkaline sodium aluminum waste liquid contained NaOH-NaAlO2 were used as flocculants, with polyacrylamide (PAM) as coagulation. When the dosage of FeSO4 was 2.66 g/L (pH 5.5), the wastewater pH value of adding alkaline sodium aluminum waste liquid was 8, and the dosage of PAM was 1 mg/L, the optimum result was obtained. A test device of co-coagulation flotation reactor was designed on the basis of the conglutination of bubble, flocci and turbulent flotation theory. In the device, the gas-1iuid mixed pump substituted the air compressor and the pressure releaser. The combination of coagulation and air flotation were realized. The pump is a new kind of air saturation equipment. The air compressor and the pressure releaser were used commonly in traditional air flotation device. The results of treatment of the tannery wastewater showed a stable state, when the operating pressure was 5×10(5) Pa, circumfluence ratio was 225%.

  4. A new approach using coagulation rate constant for evaluation of turbidity removal

    NASA Astrophysics Data System (ADS)

    Al-Sameraiy, Mukheled

    2017-06-01

    Coagulation-flocculation-sedimentation processes for treating three levels of bentonite synthetic turbid water using date seeds (DS) and alum (A) coagulants were investigated in the previous research work. In the current research, the same experimental results were used to adopt a new approach on a basis of using coagulation rate constant as an investigating parameter to identify optimum doses of these coagulants. Moreover, the performance of these coagulants to meet (WHO) turbidity standard was assessed by introducing a new evaluating criterion in terms of critical coagulation rate constant (kc). Coagulation rate constants (k2) were mathematically calculated in second order form of coagulation process for each coagulant. The maximum (k2) values corresponded to doses, which were obviously to be considered as optimum doses. The proposed criterion to assess the performance of coagulation process of these coagulants was based on the mathematical representation of (WHO) turbidity guidelines in second order form of coagulation process stated that (k2) for each coagulant should be ≥ (kc) for each level of synthetic turbid water. For all tested turbid water, DS coagulant could not satisfy it. While, A coagulant could satisfy it. The results obtained in the present research are exactly in agreement with the previous published results in terms of finding optimum doses for each coagulant and assessing their performances. On the whole, it is recommended considering coagulation rate constant to be a new approach as an indicator for investigating optimum doses and critical coagulation rate constant to be a new evaluating criterion to assess coagulants' performance.

  5. A new approach using coagulation rate constant for evaluation of turbidity removal

    NASA Astrophysics Data System (ADS)

    Al-Sameraiy, Mukheled

    2015-09-01

    Coagulation-flocculation-sedimentation processes for treating three levels of bentonite synthetic turbid water using date seeds (DS) and alum (A) coagulants were investigated in the previous research work. In the current research, the same experimental results were used to adopt a new approach on a basis of using coagulation rate constant as an investigating parameter to identify optimum doses of these coagulants. Moreover, the performance of these coagulants to meet (WHO) turbidity standard was assessed by introducing a new evaluating criterion in terms of critical coagulation rate constant (kc). Coagulation rate constants (k2) were mathematically calculated in second order form of coagulation process for each coagulant. The maximum (k2) values corresponded to doses, which were obviously to be considered as optimum doses. The proposed criterion to assess the performance of coagulation process of these coagulants was based on the mathematical representation of (WHO) turbidity guidelines in second order form of coagulation process stated that (k2) for each coagulant should be ≥ (kc) for each level of synthetic turbid water. For all tested turbid water, DS coagulant could not satisfy it. While, A coagulant could satisfy it. The results obtained in the present research are exactly in agreement with the previous published results in terms of finding optimum doses for each coagulant and assessing their performances. On the whole, it is recommended considering coagulation rate constant to be a new approach as an indicator for investigating optimum doses and critical coagulation rate constant to be a new evaluating criterion to assess coagulants' performance.

  6. [Clinical cases of acquired coagulation inhibitors].

    PubMed

    Yamane, T; Hino, M; Ota, K; Akahori, M; Hirai, M; Inoue, T; Mugitani, A; Tatsumi, N

    2000-12-01

    The acquired coagulation factor inhibitors are classified into alloantibodies, which appear in association with supplementary treatment for congenital coagulation factor deficiency, and autoantibodies, which are spontaneously produced. We report here 2 cases of acquired factor VIII inhibitor and 1 case of factor V inhibitor. Case 1: A 52-year-old woman noted swelling of the right parotid region in March 1988. Though contrast examination was scheduled, she was admitted for detailed examination due to a markedly prolonged coagulation time. An APTT correction test suggested that decreased factor VIII activity was due to the presence of an inhibitor. Since antinuclear antibody and SS-A antibody were positive and infiltration by lymphocytes in the salivary gland acini in a lip biopsy specimen was detected, Sjögren's syndrome was diagnosed. Case 2: A 33-year-old woman had normal delivery of her second child in February 1998. In June 1998, she suffered slight contusion in the left lower limb. The affected site became swollen and painful, making walking difficult. Since both upper limbs became markedly swollen after 1 week, she visited our hospital. Prolonged APTT and a marked decrease in factor VIII activity were observed. Factor VIII inhibitor titer was high at 19 Bethesda units. Case 3: A 64-year-old man had had asymptomatic macroscopic hematuria since the beginning of August 1998 but was placed under observation since no abnormal findings were observed on various imaging tests. However, he was admitted to Osaka City General Medical Center because of vesicular tamponade. Factor V activity was markedly decreased to 1.0%. PT correction test suggested that decreased factor V activity was due to the presence of an inhibitor. The underlying disease could not be determined in this case. In patients with acquired coagulation inhibitors, bleeding symptoms are reported to be mild in many cases, and severe bleeding is rare. However, cases of death without severe bleeding or

  7. Coagulation of Charged Dust in Protoplanetary Disks

    NASA Astrophysics Data System (ADS)

    Akimkin, V.

    2017-06-01

    Electrostatic interaction affects collisional cross-section of charged dust grains. Photoelectric and collisional charging are two primary mechanisms driving grains to positive and negative potentials, respectively. By solving the Smoluchowski equation for protoplanetary disk conditions, we show that effective coagulation occurs in a layer at intermediate heights, where these two charging mechanisms compete and both negative and positive grains are present. In dark regions, where the collisional charging dominates and grains are mostly negatively charged, the electrostatic barrier effectively hampers grain growth. Similarly, in an illuminated disk atmosphere, the photoelectric charging retains positively charged population of small grains.

  8. Coagulant recovery and reuse for drinking water treatment.

    PubMed

    Keeley, James; Jarvis, Peter; Smith, Andrea D; Judd, Simon J

    2016-01-01

    Coagulant recovery and reuse from waterworks sludge has the potential to significantly reduce waste disposal and chemicals usage for water treatment. Drinking water regulations demand purification of recovered coagulant before they can be safely reused, due to the risk of disinfection by-product precursors being recovered from waterworks sludge alongside coagulant metals. While several full-scale separation technologies have proven effective for coagulant purification, none have matched virgin coagulant treatment performance. This study examines the individual and successive separation performance of several novel and existing ferric coagulant recovery purification technologies to attain virgin coagulant purity levels. The new suggested approach of alkali extraction of dissolved organic compounds (DOC) from waterworks sludge prior to acidic solubilisation of ferric coagulants provided the same 14:1 selectivity ratio (874 mg/L Fe vs. 61 mg/L DOC) to the more established size separation using ultrafiltration (1285 mg/L Fe vs. 91 mg/L DOC). Cation exchange Donnan membranes were also examined: while highly selective (2555 mg/L Fe vs. 29 mg/L DOC, 88:1 selectivity), the low pH of the recovered ferric solution impaired subsequent treatment performance. The application of powdered activated carbon (PAC) to ultrafiltration or alkali pre-treated sludge, dosed at 80 mg/mg DOC, reduced recovered ferric DOC contamination to <1 mg/L but in practice, this option would incur significant costs. The treatment performance of the purified recovered coagulants was compared to that of virgin reagent with reference to key water quality parameters. Several PAC-polished recovered coagulants provided the same or improved DOC and turbidity removal as virgin coagulant, as well as demonstrating the potential to reduce disinfection byproducts and regulated metals to levels comparable to that attained from virgin material. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Electrocoagulation versus chemical coagulation: coagulation/flocculation mechanisms and resulting floc characteristics.

    PubMed

    Harif, Tali; Khai, Moti; Adin, Avner

    2012-06-15

    Electrocoagulation (EC) and chemical coagulation (CC) are employed in water treatment for particle removal. Although both are used for similar purposes, they differ in their dosing method - in EC the coagulant is added by electrolytic oxidation of an appropriate anode material, while in CC dissolution of a chemical coagulant is used. These different methods in fact induce different chemical environments, which should impact coagulation/flocculation mechanisms and subsequent floc formation. Hence, the process implications when choosing which to apply should be significant. This study elucidates differences in coagulation/flocculation mechanisms in EC versus CC and their subsequent effect on floc growth kinetics and structural evolution. A buffered kaolin suspension served as a representative solution that underwent EC and CC by applying aluminum via additive dosing regime in batch mode. In EC an aluminum anode generated the active species while in CC, commercial alum was used. Aluminum equivalent doses were applied, at initial pH values of 5, 6.5 and 8, while samples were taken over pre-determined time intervals, and analyzed for pH, particle size distribution, ζ potential, and structural properties. EC generated fragile flocs, compared to CC, over a wider pH range, at a substantially higher growth rate, that were prone to restructuring and compaction. The results suggest that the flocculation mechanism governing EC in sweep floc conditions is of Diffusion Limited Cluster Aggregation (DCLA) nature, versus a Reaction Limited Cluster Aggregation (RLCA) type in CC. The implications of these differences are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  10. Thymoquinone Modulates Blood Coagulation in Vitro via Its Effects on Inflammatory and Coagulation Pathways

    PubMed Central

    Muralidharan-Chari, Vandhana; Kim, Jaehan; Abuawad, Ahlam; Naeem, Mubeena; Cui, Huadong; Mousa, Shaker A.

    2016-01-01

    Thymoquinone (THQ) is a major component of black seeds. Given that both THQ and black seeds exhibit anti-cancer and anti-inflammatory activities, we hypothesized that THQ will affect cancer-associated thrombosis (CAT), which is primarily triggered by tissue factor (TF) and inflammation. The effect of both black seed-extracted and purchased (“pure”) THQ on normal blood coagulation was tested with in vitro thromboelastography (TEG) and activated partial thromboplastin time (aPTT) coagulation assays. The effect of pure THQ on CAT was tested with aPTT assay using pancreatic cancer cell lines that are either positive or negative for TF, and with TEG assay using lipopolysaccharide as an inflammatory trigger. Additionally, the direct effect of THQ on the inactivation of factors IIa and Xa was assessed. Since TNF-α facilitates crosstalk between inflammation and thrombosis by triggering the NF-κB pathway, we tested THQ’s ability to interfere with this communication with a luciferase assay. Both extracted and pure THQ had minimal effects on normal blood coagulation. Pure THQ reversed CAT initiated by both TF and inflammation to basal levels (p < 0.001). Mechanistically, while THQ had minimal to no effect on factor IIa and Xa inactivation, it strongly reduced the effects of TNF-α on NF-κB elements (p < 0.001). THQ has a minimal effect on basal coagulation and can reverse CAT in vitro, possibly by interfering with the crosstalk between inflammation and coagulation. This study suggests the utility of THQ as a preventative anticoagulant and/or as a supplement to existing chemotherapies and anticoagulant therapies. PMID:27043539

  11. Thymoquinone Modulates Blood Coagulation in Vitro via Its Effects on Inflammatory and Coagulation Pathways.

    PubMed

    Muralidharan-Chari, Vandhana; Kim, Jaehan; Abuawad, Ahlam; Naeem, Mubeena; Cui, Huadong; Mousa, Shaker A

    2016-03-30

    Thymoquinone (THQ) is a major component of black seeds. Given that both THQ and black seeds exhibit anti-cancer and anti-inflammatory activities, we hypothesized that THQ will affect cancer-associated thrombosis (CAT), which is primarily triggered by tissue factor (TF) and inflammation. The effect of both black seed-extracted and purchased ("pure") THQ on normal blood coagulation was tested with in vitro thromboelastography (TEG) and activated partial thromboplastin time (aPTT) coagulation assays. The effect of pure THQ on CAT was tested with aPTT assay using pancreatic cancer cell lines that are either positive or negative for TF, and with TEG assay using lipopolysaccharide as an inflammatory trigger. Additionally, the direct effect of THQ on the inactivation of factors IIa and Xa was assessed. Since TNF-α facilitates crosstalk between inflammation and thrombosis by triggering the NF-κB pathway, we tested THQ's ability to interfere with this communication with a luciferase assay. Both extracted and pure THQ had minimal effects on normal blood coagulation. Pure THQ reversed CAT initiated by both TF and inflammation to basal levels (p < 0.001). Mechanistically, while THQ had minimal to no effect on factor IIa and Xa inactivation, it strongly reduced the effects of TNF-α on NF-κB elements (p < 0.001). THQ has a minimal effect on basal coagulation and can reverse CAT in vitro, possibly by interfering with the crosstalk between inflammation and coagulation. This study suggests the utility of THQ as a preventative anticoagulant and/or as a supplement to existing chemotherapies and anticoagulant therapies.

  12. Cosmic dust synthesis by accretion and coagulation

    NASA Technical Reports Server (NTRS)

    Praburam, G.; Goree, J.

    1995-01-01

    The morphology of grains grown by accretion and coagulation is revaled by a new laboratory method of synthesizing cosmic dust analogs. Submicron carbon particles, grown by accretion of carbon atoms from a gas, have a spherical shape with a cauliflower-like surface and an internal micro-structure of radial columns. This shape is probably common for grains grown by accretion at a temperature well below the melting point. Coagulated grains, consisting of spheres that collided to form irregular strings, were also synthesized. Another shape we produced had a bumpy non- spherical morphology, like an interplanetary particle collected in the terrestrial stratosphere. Besides these isolated grains, large spongy aggregates of nanometer-size particles were also found for various experimental conditions. Grains were synthesized using ions to sputter a solid target, producing an atomic vapor at a low temperature. The ions were provided by a plasma, which also provided electrostatic levitation of the grains during their growth. The temporal development of grain growth was studied by extinguishing the plasma after various intervals.

  13. Blood and coagulation support in trauma care.

    PubMed

    Hess, John R

    2007-01-01

    Injuries are common and account for almost 15% of all blood use in the U.S. The historic view that the coagulopathy associated with severe injury was largely dilutional is being replaced by epidemiologic and molecular evidence for a distinct syndrome of trauma-associated coagulopathy. This coagulopathy of trauma is the sum of the effects of blood loss and dilution, coagulation factor and platelet consumption, hypothermic platelet dysfunction and acidosis-induced decreases in coagulation factor activity, and fibrinolysis. Preventing the coagulopathy of trauma is best accomplished by preventing injury and hypothermia. Treating the coagulopathy of trauma requires its early recognition, prompt control of hemorrhage with local and systemic treatments, including in some patients the use of plasma instead of crystalloid solutions, and the prompt treatment of acidosis and hypothermia. The planned early use of allogenic plasma to treat many tens of thousands of massively transfused patients each year creates new demands for the immediate availability and improved safety of plasma products.

  14. Tissue Factor in Coagulation: Which? Where? When?

    PubMed Central

    Butenas, Saulius; Orfeo, Thomas; Mann, Kenneth G.

    2009-01-01

    Tissue factor (TF) is an integral membrane protein, normally separated from the blood by the vascular endothelium, which plays a key role in the initiation of blood coagulation. With a perforating vascular injury, TF becomes exposed to blood and binds plasma factor VIIa. The resulting complex initiates a series of enzymatic reactions leading to clot formation and vascular sealing. In some pathologic states, circulating blood cells express TF as a result of exposure to an inflammatory stimulus leading to intravascular clotting, vessel occlusion and thrombotic pathology. Numerous controversies have arisen related to the influence of structural features of TF, its presentation and its function. There are contradictory reports about the synthesis and presentation of TF on blood cells and the presence (or absence) of functionally active TF circulating in normal blood either on microparticles or as a soluble protein. In this review we discuss TF structure-function relationships and the role of TF during various phases of the blood coagulation process. We also highlight controversies concerning the expression/presence of TF on various cells and in blood in normal and pathologic states. PMID:19592470

  15. Inherited coagulation disorders in southern Iran.

    PubMed

    Karimi, M; Yarmohammadi, Hirad; Ardeshiri, R; Yarmohammadi, Hooman

    2002-11-01

    A comprehensive survey concerning the Shiraz Hemophilia Society and the associated haemophilia treatment centre was undertaken in April 2002 to collect data on demographics, signs and symptoms in the southern Iranian population with haemophilia and allied disorders. The total number of patients with coagulation disorders was 367. Haemophilia A (factor [F] VIII deficiency) was found in 271, 39 had haemophilia B (FIX deficiency) and 24 had von Willebrand disease. The rare coagulation disorders (n = 33) included 11 patients with FX deficiency; 10 with FVII; six with FXIII; two with afibrinogenaemia; two with FXI; one with combined FVIII and FV; and one with combined FVII, FVIII and FIX deficiency. The prevalence was 6.64 per 100,000 inhabitants. The most common symptoms were haemarthrosis, haematomas and epistaxis. None of the patients were human immunodeficiency virus positive but 47 (15%) were hepatitis C virus positive and two (0.7%) were hepatitis B positive, so that the rate of transfusion-transmitted infections was lower compared with other populations.

  16. Coagulation chemistries for silica removal from cooling tower water.

    SciTech Connect

    Nyman, May Devan; Altman, Susan Jeanne; Stewart, Tom

    2010-02-01

    The formation of silica scale is a problem for thermoelectric power generating facilities, and this study investigated the potential for removal of silica by means of chemical coagulation from source water before it is subjected to mineral concentration in cooling towers. In Phase I, a screening of many typical as well as novel coagulants was carried out using concentrated cooling tower water, with and without flocculation aids, at concentrations typical for water purification with limited results. In Phase II, it was decided that treatment of source or make up water was more appropriate, and that higher dosing with coagulants delivered promising results. In fact, the less exotic coagulants proved to be more efficacious for reasons not yet fully determined. Some analysis was made of the molecular nature of the precipitated floc, which may aid in process improvements. In Phase III, more detailed study of process conditions for aluminum chloride coagulation was undertaken. Lime-soda water softening and the precipitation of magnesium hydroxide were shown to be too limited in terms of effectiveness, speed, and energy consumption to be considered further for the present application. In Phase IV, sodium aluminate emerged as an effective coagulant for silica, and the most attractive of those tested to date because of its availability, ease of use, and low requirement for additional chemicals. Some process optimization was performed for coagulant concentration and operational pH. It is concluded that silica coagulation with simple aluminum-based agents is effective, simple, and compatible with other industrial processes.

  17. Polytitanium sulfate (PTS): Coagulation application and Ti species detection.

    PubMed

    Zhao, Yanxia; Phuntsho, Sherub; Gao, Baoyu; Shon, Hokyong

    2017-02-01

    Interest in the development of inorganic polymerized coagulants is growing; however, there are only limited studies on the synthesis of polytitanium coagulants, which are expected to exhibit improved coagulation efficiency with better floc properties. This study presents the synthesis of polytitanium sulfate (PTS) for potential application in water purification, followed by characterization of PTS flocs and titanium species detection. Stable PTS solutions were successfully synthesized and standard jar tests were conducted to evaluate their coagulation efficiency. Electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) speciation analysis revealed that a variety of mononuclear and polynuclear complexes were formed in PTS solution, indicating the polymeric nature of the synthesized coagulant. Floc characteristics were studied through on-line monitoring of floc size using a laser diffraction particle size analyzer. Results showed that PTS had a comparable or in some cases even higher organic matter and particulate removal efficiency than Ti(SO4)2. The effluent pH after PTS coagulation significantly improved toward desirable values closer to neutral pH. Properties of flocs formed by PTS were significantly improved in terms of floc size, growth rate and structure. This study showed that PTS could be an efficient and promising coagulant for water purification, with the additional benefit that its coagulated sludge can be used to recover valuable TiO2 nanoparticles for various commercial applications. Copyright © 2016. Published by Elsevier B.V.

  18. Analysis and optimization of coagulation and flocculation process

    NASA Astrophysics Data System (ADS)

    Saritha, V.; Srinivas, N.; Srikanth Vuppala, N. V.

    2017-03-01

    Natural coagulants have been the focus of research of many investigators through the last decade owing to the problems caused by the chemical coagulants. Optimization of process parameters is vital for the effectiveness of coagulation process. In the present study optimization of parameters like pH, dose of coagulant and mixing speed were studied using natural coagulants sago and chitin in comparison with alum. Jar test apparatus was used to perform the coagulation. The results showed that the removal of turbidity was up to 99 % by both alum and chitin at lower doses of coagulant, i.e., 0.1-0.3 g/L, whereas sago has shown a reduction of 70-100 % at doses of 0.1 and 0.2 g/L. The optimum conditions observed for sago were 6 and 7 whereas chitin was stable at all pH ranges, lower coagulant doses, i.e., 0.1-0.3 g/L and mixing speed—rapid mixing at 100 rpm for 10 min and slow mixing 20 rpm for 20 min. Hence, it can be concluded that sago and chitin can be used for treating water even with large seasonal variation in turbidity.

  19. Argon beam coagulator electrode tip mimicking a metallic foreign body.

    PubMed

    Gladish, Gregory W; Dunnington, Joel S; Chasen, Marvin H

    2003-07-01

    Our purpose is to describe the appearance of an argon beam coagulator electrode tip that may become fractured and detached during surgery. Knowledge of the potential for fracture and detachment and recognition of the characteristic radiographic appearance of the argon beam coagulator electrode tip allows radiographic identification of this metallic foreign body.

  20. Characteristics of particle coagulation in an underground parking lot.

    PubMed

    Zhao, Yu; Kato, Shinsuke; Zhao, Jianing

    2015-12-01

    Particles in vehicle exhaust plumes in underground parking lots have adverse health effects due to the enclosed environment in which they are released and the temperature difference between the tailpipe and ambient environment; at the same time, particle coagulation might be obvious near the tailpipe in an underground parking lot. In the present study, airflow and temperature fields were calculated using the Realizable k-ε model, and the Eulerian particle transport model was selected in the numerical simulation of particle concentration dispersion. Polydisperse thermal coagulation due to Brownian collisions was employed to calculate the particle coagulation. The results show that particle coagulation rate and half-time were significant within 1 m from the tailpipe. The variations in the particle coagulation rate and half-time were similar, but their directions were opposite. Air exhaust time was nearly four times longer than averaged half-time and 40 times longer than minimum half-time. The peak particle diameter increased approximately 1.43 times due to coagulation. A double particle concentration at the tailpipe caused the fourfold rise in the particle coagulation rate in the distance ranging less than 1 m from the tailpipe. An increase in exhaust velocity at the tailpipe could shorten the obvious range of particle coagulation along the centerline of the tailpipe from 1 to 0.8 m in the study.

  1. Impact of source water quality on multiwall carbon nanotube coagulation.

    PubMed

    Holbrook, R David; Kline, Carly N; Filliben, James J

    2010-02-15

    Potable water treatment facilities may become an important barrier in limiting human exposure to engineered nanoparticles (ENPs) as ENPs begin to contaminate natural aquatic systems. Coagulation of ENPs will likely be a major process that controls the ENP fate and the subsequent removal in the aqueous phase. The influence that source water quality has on ENP coagulation is still relatively unknown. The current study uses a 2(3) x 2(4-1) fractional factorial design to identify seven key surface water constituents that affect multiwall carbon nanotube (MWCNT) coagulation. These seven factors include: influent concentrations of kaolin, organic matter (OM), alginate, and MWCNTs; type and dosage of coagulant; and method of MWCNT stabilization. MWCNT removal was most affected by coagulant type and dosage, with alum outperforming ferric chloride at circumneutral pH. None of the other factors were universally significant but instead depended on coagulant type, dose, and method of stabilization. In all cases where factors were found to have a significant impact on MWCNT removal, however, the relationship was consistent: higher influent concentrations of kaolin and alginate improved MWCNT removal while higher influent concentrations of OM hindered MWCNT coagulation. Once MWCNTs are released into the natural environment, their coagulation behavior will be determined by the type and quantity of pollutants (i.e., factors) present in the aquatic environment and are governed by the same mechanisms that influence the colloidal stability of "natural" nanoparticles.

  2. Metals in airpollution particles decrease whole blood coagulation time

    EPA Science Inventory

    The mechanism underlying the pro-coagulative effect of air pollution particle exposure is not known. We tested the postulate that 1) the soluble fraction ofan air pollution particle can affect whole blood coagulation time and 2) metals included in the soluble fraction are respons...

  3. Metals in airpollution particles decrease whole blood coagulation time

    EPA Science Inventory

    The mechanism underlying the pro-coagulative effect of air pollution particle exposure is not known. We tested the postulate that 1) the soluble fraction ofan air pollution particle can affect whole blood coagulation time and 2) metals included in the soluble fraction are respons...

  4. Analysis and optimization of coagulation and flocculation process

    NASA Astrophysics Data System (ADS)

    Saritha, V.; Srinivas, N.; Srikanth Vuppala, N. V.

    2015-02-01

    Natural coagulants have been the focus of research of many investigators through the last decade owing to the problems caused by the chemical coagulants. Optimization of process parameters is vital for the effectiveness of coagulation process. In the present study optimization of parameters like pH, dose of coagulant and mixing speed were studied using natural coagulants sago and chitin in comparison with alum. Jar test apparatus was used to perform the coagulation. The results showed that the removal of turbidity was up to 99 % by both alum and chitin at lower doses of coagulant, i.e., 0.1-0.3 g/L, whereas sago has shown a reduction of 70-100 % at doses of 0.1 and 0.2 g/L. The optimum conditions observed for sago were 6 and 7 whereas chitin was stable at all pH ranges, lower coagulant doses, i.e., 0.1-0.3 g/L and mixing speed—rapid mixing at 100 rpm for 10 min and slow mixing 20 rpm for 20 min. Hence, it can be concluded that sago and chitin can be used for treating water even with large seasonal variation in turbidity.

  5. Coagulation pretreatment for ultrafiltration of deinking effluents containing flexographic inks

    Treesearch

    Bruno Chabot; Gopal A. Krishnagopalan; Said Abubakr

    1999-01-01

    This study was carried out to determine the potential of coagulation pretreatment with organic or inorganic coagulants to improve ultrafiltration performance during processing of wash deinking effluents containing flexographic inks. Wash filtrate effluents generated from mixtures of old flexographic and offset newspapers and old magazines were pretreated with a...

  6. Pre-coagulation for microfiltration of an upland surface water.

    PubMed

    Pikkarainen, A T; Judd, S J; Jokela, J; Gillberg, L

    2004-01-01

    The effect of different coagulants on cake formation and hydraulic resistance in membrane filtration of strongly coloured (SUVA> or =4.8) upland surface water has been studied at bench-scale under constant pressure conditions. Coagulants used were aluminium sulphate, polyaluminium chloride, ferric chloride and ferric sulphate. Optimisation of coagulation parameters was carried by conventional jar testing. The R'c (specific cake resistance in m(-2)) values were determined for all coagulants over a range of coagulant doses and slow mixing flocculation periods. Experiments indicated slight differences in cake formation trends between ferric- and aluminium-based coagulants and chloride and sulphate counterions, but that the range of measured R'c values was small (0.9 and 2.6 x 10(18) m(-2)) over the range of doses studied. Greater than 99% UV(254) removal was achieved with every coagulant, whereas dissolved organic carbon (DOC) removal ranged from 78% to 88%. Optimisation of the pre-coagulation-membrane filtration process suggests ferric chloride to be slightly superior for the feedwater matrix studied on the basis of DOC removal, whereas ferric sulphate gave slightly lower filter cake specific resistance values.

  7. Adherence and Coagulation Assays in Dabigatran-treated Patients With Atrial Fibrillation

    ClinicalTrials.gov

    2017-09-12

    Atrial Fibrillation; Medication Adherence; Blood Coagulation Tests; Anticoagulants; Circulating, Hemorrhagic Disorder; Drug Effect; Drug Use; Drug Toxicity; Drug Intolerance; Blood Clot; Blood Coagulation Disorder; Laboratory Problem; Bleeding; Thrombosis

  8. Performance and characterization of a new tannin-based coagulant

    NASA Astrophysics Data System (ADS)

    Beltrán-Heredia, J.; Sánchez-Martín, J.; Gómez-Muñoz, C.

    2012-09-01

    Diethanolamine and formaldehyde were employed to cationize tannins from black wattle. This novel coagulant called CDF was functionally characterized in removing sodium dodecylbenzene sulfonate (anionic surfactant) and Palatine Fast Black WAN (azoic dye). Refined tannin-derived commercial coagulants exhibited similar efficiency, while CDF presented higher coagulant ability than alum, a usual coagulant agent. Low doses of CDF (ca. 100 mg L-1) were able to remove more than 70 % of surfactant and more than 85 % of dye (initial pollutant concentration of ca. 100 mg L-1) and it presented no temperature affection and worked at a relatively wide pH range. Surfactant and dye removal responded to the classical coagulant-and-adsorption models, such as Frumkin-Fowler-Guggenheim or Gu and Zhu in the case of surfactant, and Langmuir and Freundlich in the case of dye.

  9. Analysis of Coagulation Processes for the Groundwater Treatment

    NASA Astrophysics Data System (ADS)

    Albrektiene, Ramune; Rimeika, Mindaugas; Jurkiene, Anzelika

    2013-06-01

    Coagulation process is widely used for removal of natural organic matters (NOM) and for water color intensity reduction. The efficiency of coagulation process depends on many different factors. Aim of this research is to investigate coagulation process under different conditions. During the research coagulation process was held at different pH values (5.5; 6.0; 6.5), at different water alkalinity and at different water turbidity. It was found that removal of NOM and water color intensity reduction is most effective at pH values from 5.5 to 6.0. At these conditions water color intensity reduction is most efficient, but removal of dissolved organic carbon (DOC) is the lowest. During the research it was also found that different water alkalinity and turbidity do not make significant influence on efficiency of coagulation process.

  10. Blood coagulation evaluation of N-alkylated chitosan.

    PubMed

    Chen, Zihao; Yao, Xinpei; Liu, Lu; Guan, Jing; Liu, Mengyuan; Li, Zhihong; Yang, Jian; Huang, Shujie; Wu, Jimin; Tian, Feng; Jing, Miaolei

    2017-10-01

    N-Alkylated chitosan (NACS) may improve the haemostatic efficiency of chitosan (CS). To study its coagulation capability and function, a series of NACS with various carbon chain lengths and substitution degrees (SD) of alkyl groups were synthesized and characterized by FTIR, NMR, and elemental analysis. Haemolysis and toxicity assays revealed that NACS showed good biocompatibility. In vitro blood clotting tests indicated that NACS had better haemostatic activity than CS, of which N-octadecyl CS with 3.85% SD showed the best results. Blood plasma coagulation tests showed that NACS was not favourable for activating coagulation factors. Platelet adhesion, intracellular Ca(2+), and CD62p measurements demonstrated that the coagulation properties of NACS were not related to platelet activation. Erythrocyte adhesion examination indicated that blood coagulation of NACS may be attributable to its effects on erythrocytes. This study suggests that NACS is an ideal candidate for clotting. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Interplay between coagulation and vascular inflammation in sickle cell disease

    PubMed Central

    Sparkenbaugh, Erica; Pawlinski, Rafal

    2013-01-01

    Sickle cell disease is the most common inherited hematologic disorder that leads to the irreversible damage of multiple organs. Although sickling of red blood cells and vaso-occlusion are central to the pathophysiology of sickle cell disease the importance of hemolytic anemia and vasculopathy has been recently recognized. Hypercoagulation state is another prominent feature of sickle cell disease and is mediated by activation of both intrinsic and extrinsic coagulation pathways. Growing evidence demonstrates that coagulation may not only contribute to the thrombotic complications, but also to vascular inflammation associated with this disease. This article summarizes the role of vascular inflammation and coagulation activation, discusses potential mechanisms responsible for activation of coagulation and reviews recent data demonstrating the crosstalk between coagulation and vascular inflammation in sickle cell disease. PMID:23593937

  12. Coagulation disorders and inhibitors of coagulation in children from Mansoura, Egypt.

    PubMed

    Abdelrazik, Nabil; Rashad, Hayam; Selim, Tarek; Tharwat, Layla

    2007-08-01

    Disorders of coagulation in children often prove challenging to the medical care team. The aims of this study were to assess the spectrum and prevalence of coagulation disorders among children attending Mansoura University Children Hospital (MUCH), Mansoura, Egypt. A total of 105 pediatric patients were referred to MUCH. They were divided into two groups: congenital coagulation disorders (75 cases, age 45.36 +/- 48.59 months), and acquired coagulation disorders (30 cases, age 56.13 +/- 61.61 months). All patients were subjected to thorough history taking including the nature of bleeding, family, past history, mode of inheritance, and detailed physical findings. Hemostatic tests included: platelet count, bleeding time (BT), prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT). Specific tests in the congenital group include assay of coagulation factors according to each disorder, Von Willebrand factor assay, ristocetin aggregation test, APTT mixing study for detection of inhibitors in complicated hemophilia cases, F VIII C to VWAg ratio with cut off 0.7 for detection of carriers in some hemophilia A families. Congenital disorders constituted 71.4% of the studied cases vs. 28.6% for acquired disorders. Hemophilia A (42.85%), hemophilia B (14.28%) and liver diseases (14.28%) represented the majority of the studied cases. Mild and moderate cases of hemophilia A and B are more frequent than severe cases in both types. Male sex is more frequent than female in the congenital group (94.7 vs. 5.3%, P < 0.001). Direct correlation existed between factor level assay and severity of hemophilia (r = 0.73, P = 0.006). Three mothers and one sister were identified as carrier out of four families. Anti-clotting factors inhibitor was detected in 18.2% of patients with hemophilia A and in 9.1% with hemophilia B. In conclusion, our study found that hemophilias are the most prevalent congenital coagulation disorders among children. Attention must be

  13. The Role for Coagulation Markers in Mild Snakebite Envenomations

    PubMed Central

    Moriarity, Risa S; Dryer, Sylvia; Replogle, William; Summers, Richard L

    2012-01-01

    Introduction The majority of patients seeking medical treatment for snakebites do not suffer from severe envenomation. However, no guidelines exist for ordering coagulation markers in patients with minimal or moderate envenomation, nor in those who do not receive antivenom. In this study, we sought to determine whether it was possible to limit the practice of ordering coagulation studies to those patients suffering severe envenomation, rattlesnake envenomation, or both. Methods A retrospective chart review was performed on all cases of crotalid snakebite presenting to an adult emergency department (ED) from April 1998 to June 2006. Each chart was abstracted for patient's age, gender, type of snake (if known), severity of envenomation at initial presentation, coagulation test results, whether antivenom was administered, and whether the patient was admitted. Results Over an approximately 8-year period, 131 snakebite cases presented that met the inclusion criteria, of which 35 (26.7%) had some type of coagulation marker abnormality. Limiting coagulation testing to patients suffering severe envenomation or rattlesnake envenomation would have resulted in failure to identify 89% or 77%, respectively, of the 35 patients who were found to have at least 1 abnormal coagulation marker. Conclusion Our study failed to identify a subset of patients that could be defined as low risk or for whom coagulation marker testing could be foregone. This study suggests that coagulation tests should be routinely performed on all patients presenting to the ED with complaints of envenomation by copperheads, moccasins, or rattlesnakes. Further clarification of when coagulation markers are indicated may require a prospective study that standardizes snake identification and the timing of coagulation marker testing. PMID:22461925

  14. Enhanced arsenite removal through surface-catalyzed oxidative coagulation treatment.

    PubMed

    Li, Yue; Bland, Garret D; Yan, Weile

    2016-05-01

    Arsenic being a naturally-occurring groundwater contaminant is subject to stringent water quality regulations. Coagulation and adsorption are widely used methods to treat arsenic-contaminated water, however, these treatments have been reported to be less efficient for the removal of arsenite (As(III)) than arsenate (As(V)). In this study, the feasibility of in situ oxidation of As(III) during coagulation was investigated in two systems: Fe(II) or H2O2-assisted oxidative coagulation treatment using ferric chloride as the coagulant. This setup exploits the catalytic property of the fresh formed Fe(III) hydroxide colloids in coagulation suspension to mediate the production of reactive oxidants capable of As(III) oxidation. Fe(II)-assisted coagulation brought about small improvements in As(III) removal compared to treatment with Fe(III) coagulant alone, however, its arsenic removal efficiency is strongly dependent on pH (observed optimal pH = 7-9). Addition of H2O2 together with ferric chloride led to a significant enhancement in arsenic retention at pH 6-8, with final arsenic concentrations well below the U.S.EPA regulatory limit (10 μg/L). H2O2-assisted oxidative coagulation can attain reliable As(III) removal over a broad pH range of 4-9. Radical quenching experiments reveal the participation of superoxide radical in As(III) removal in the oxidative coagulation systems. Phosphate (at > 0.1 mM) strongly suppresses As(III) removal efficiency, whereas carbonate and humic acid pose a minor impact. Overall, the results suggest that a low dose addition of H2O2 along with ferric coagulant is a feasible method for the existing water treatment facilities to achieve improved As(III) removal efficiency. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Predictive factors for beneficial application of high-frequency electromagnetics for tumour vaporization and coagulation in neurosurgery

    PubMed Central

    Ritz, Rainer; Heckl, Stefan; Safavi-Abbasi, Sam; Feigl, Guenther C; Krischek, Boris; Lüdemann, Wolf; Mirzayan, Javed M; Koerbel, Andrei; Samii, Madjid; Tatagiba, Marcos; Gharabaghi, Alireza

    2008-01-01

    Objective To identify preoperative and intraoperative factors and conditions that predicts the beneficial application of a high-frequency electromagnetic field (EMF) system for tumor vaporization and coagulation. Methods One hundred three subsequent patients with brain tumors were microsurgically treated using the EMF system in addition to the standard neurosurgical instrumentarium. A multivariate analysis was performed regarding the usefulness (ineffective/useful/very helpful/essential) of the new technology for tumor vaporization and coagulation, with respect to tumor histology and location, tissue consistency and texture, patients' age and sex. Results The EMF system could be used effectively during tumor surgery in 83 cases with an essential contribution to the overall success in 14 cases. In the advanced category of effectiveness (very helpful/essential), there was a significant difference between hard and soft tissue consistency (50 of 66 cases vs. 3 of 37 cases). The coagulation function worked well (very helpful/essential) for surface (73 of 103 cases) and spot (46 of 103 cases) coagulation when vessels with a diameter of less than one millimeter were involved. The light-weight bayonet hand piece and long malleable electrodes made the system especially suited for the resection of deep-seated lesions (34 of 52 cases) compared to superficial tumors (19 of 50 cases). The EMF system was less effective than traditional electrosurgical devices in reducing soft glial tumors. Standard methods where also required for coagulation of larger vessels. Conclusion It is possible to identify factors and conditions that predict a beneficial application of high-frequency electromagnetics for tumor vaporization and coagulation. This allows focusing the use of this technology on selective indications. PMID:18445296

  16. Direct observation on the Brownian coagulation of PSL particles through optical microscope in the regime near critical coagulation concentration (CCC).

    PubMed

    Fukasawa, Tomonori; Adachi, Yasuhisa

    2010-04-15

    Microscopic monitoring of floc structure, floc size distribution and the rate of coagulation was carried out for Brownian coagulation of PSL particles. Experiments were designed for the condition of salt concentration that is slightly below critical coagulation concentration (CCC). The density of the solvent was controlled by using deuterium oxide (D(2)O) to avoid sedimentation. Results are summarized as follows: (i) Near CCC, floc restructuring from the beginning stage of coagulation was evidenced, i.e., the ratio of linear triplet is found to be remarkably reduced as compared with the result obtained for the case of rapid coagulation which was implemented under sufficiently high salt concentration. (ii) The increase of fractal dimension from 1.8 in the case of rapid coagulation to 2.2 was confirmed by the analysis of mass balance using size distribution of flocs. This increment resulted in the decrease of effective excluded volume of flocs. (iii) The rate of coagulation was constant until later stage. This result contrasts to the result of rapid coagulation [T. Fukasawa, Y. Adachi, J. Colloid Interface Sci. 304 (2006) 115]. 2010 Elsevier Inc. All rights reserved.

  17. A hitherto undescribed plasma factor acting at the contact phase of blood coagulation (Flaujeac factor): case report and coagulation studies.

    PubMed

    Lacombe, M J; Varet, B; Levy, J P

    1975-11-01

    This paper reports an asymptomatic coagulation defect responsible for an abnormality at the contact phase of blood coagulation in vitro, distinct from Hageman factor and Fletcher factor deficiencies. Coagulation studies in a 50-yr-old French woman without bleeding tendency revealed the following results: whole-blood clotting time in glass tubes and activated partial thromboplastin time with kaolin and ellagic acid were greatly prolonged; one-stage prothrombin was normal; no circulating anticoagulant was detected, and the infusion of normal plasma corrected the coagulation defect with an estimated half-life of 6.5 days; the levels of factor VIII, IX, XI, and XII were normal; mutual correction was obtained with a Fletcher factor-deficient plasma; the level of whole complement was normal. Studies of the contact phase of blood coagulation and contact-induced fibrinolysis showed the same abnormalities as in Hageman factor- and Fletcher-deficient plasmas. These results indicate that the patient's plasma is deficient in a previously undescribed coagulation factor, which participates in the initial stage of the blood coagulation process in vitro. Family studies revealed consanguinity in the propositus' parents. The assay of this newly described factor in the propositus' children revealed a partial defect, compatible with a heterozygous state, in three of the four tested children. This indicates a recessive inheritance of this new blood coagulation defect.

  18. Evaluation of optical coherence tomography for the measurement of the effects of activators and anticoagulants on the blood coagulation in vitro.

    PubMed

    Xu, Xiangqun; Geng, Jinhai; Liu, Gangjun; Chen, Zhongping

    2013-08-01

    Optical properties of human blood during coagulation were studied using optical coherence tomography (OCT) and the parameter of clotting time derived from the 1/e light penetration depth (d(1/e)) versus time was developed in our previous work. In this study, in order to know if a new OCT test can characterize the blood-coagulation process under different treatments in vitro, the effects of two different activators (calcium ions and thrombin) and anticoagulants, i.e., acetylsalicylic acid (ASA, a well-known drug aspirin) and melagatran (a direct thrombin inhibitor), at various concentrations are evaluated. A swept-source OCT system with a 1300 nm center wavelength is used for detecting the blood-coagulation process in vitro under a static condition. A dynamic study of d1/e reveals a typical behavior due to coagulation induced by both calcium ions and thrombin, and the clotting time is concentration-dependent. Dose-dependent ASA and melagatran prolong the clotting times. ASA and melagatran have different effects on blood coagulation. As expected, melagatran is much more effective than ASA in anticoagulation by the OCT measurements. The OCT assay appears to be a simple method for the measurement of blood coagulation to assess the effects of activators and anticoagulants, which can be used for activator and anticoagulant screening.

  19. Evaluation of Optical Coherence Tomography for the Measurement of the Effects of Activators and Anticoagulants on the Blood Coagulation In Vitro

    PubMed Central

    Geng, Jinhai; Liu, Gangjun; Chen, Zhongping

    2013-01-01

    Optical properties of human blood during coagulation were studied using optical coherence tomography (OCT) and the parameter of clotting time derived from the 1/e light penetration depth (d1/e) versus time was developed in our previous work. In this study, in order to know if a new OCT test can characterize the blood-coagulation process under different treatments in vitro, the effects of two different activators (calcium ions and thrombin) and anticoagulants, i.e., acetylsalicylic acid (ASA, a well-known drug aspirin) and melagatran (a direct thrombin inhibitor), at various concentrations are evaluated. A swept-source OCT system with a 1300 nm center wavelength is used for detecting the blood-coagulation process in vitro under a static condition. A dynamic study of d1/e reveals a typical behavior due to coagulation induced by both calcium ions and thrombin, and the clotting time is concentration-dependent. Dose-dependent ASA and melagatran prolong the clotting times. ASA and melagatran have different effects on blood coagulation. As expected, melagatran is much more effective than ASA in anticoagulation by the OCT measurements. The OCT assay appears to be a simple method for the measurement of blood coagulation to assess the effects of activators and anticoagulants, which can be used for activator and anticoagulant screening. PMID:23392340

  20. Effect of speciation transformation on the coagulation behavior of Al(13) and Al(13) aggregates.

    PubMed

    Wu, Xiaohong; Ye, Changqing; Wang, Dongsheng; Ge, Xiaopeng; Tang, Hongxiao

    2009-01-01

    Flocculation of kaolin suspension with aluminium fractal polycations was investigated as a function of aluminium concentration and pH. Aluminium flocculants included Al(13) and Al(13) aggregates with OH/Al ratio of 2.6 and 2.8, respectively. The flocculation kinetics and floc size distribution were monitored by light scattering. The characterization of flocculants showed that the tridecatmer Al(13) and bridged [Al(13)](n) with out-sphere structure were the dominant species for all flocculants in a wide pH range. The coagulation results indicated that the pre and in situ-formed [Al(13)](n) play a key role in removing particles. With the increasing concentration of [Al(13)](n), coagulation mechanisms were transformed from charge-neutralization, electro-patch coagulation to bridge-aggregation. Moreover, sweep-flocculation was involved at higher dosage besides other three mechanisms when amorphous aluminium oxides formed. Hence, chemical interaction between particles and flocculants evolved from surface adsorption to surface precipitation for aluminium polycations by virtue of species transformation.

  1. Production of functional coagulation factor VIII from iPSCs using a lentiviral vector.

    PubMed

    Kashiwakura, Y; Ohmori, T; Mimuro, J; Madoiwa, S; Inoue, M; Hasegawa, M; Ozawa, K; Sakata, Y

    2014-01-01

    The use of induced pluripotent stem cells (iPSCs) as an autologous cell source has shed new light on cell replacement therapy with respect to the treatment of numerous hereditary disorders. We focused on the use of iPSCs for cell-based therapy of haemophilia. We generated iPSCs from mesenchymal stem cells that had been isolated from C57BL/6 mice. The mouse iPSCs were generated through the induction of four transcription factor genes Oct3/4, Klf-4, Sox-2 and c-Myc. The derived iPSCs released functional coagulation factor VIII (FVIII) following transduction with a simian immunodeficiency virus vector. The subcutaneous transplantation of iPSCs expressing FVIII into nude mice resulted in teratoma formation, and significantly increased plasma levels of FVIII. The plasma concentration of FVIII was at levels appropriate for human therapy at 2-4 weeks post transplantation. Our data suggest that iPSCs could be an attractive and prospective autologous cell source for the production of coagulation factor, and that engineered iPSCs expressing coagulation factor might provide a cell-based therapeutic strategy appropriate for haemophilia. © 2013 John Wiley & Sons Ltd.

  2. Structure and dynamics of zymogen human blood coagulation factor X.

    PubMed Central

    Venkateswarlu, Divi; Perera, Lalith; Darden, Tom; Pedersen, Lee G

    2002-01-01

    The solution structure and dynamics of the human coagulation factor X (FX) have been investigated to understand the key structural elements in the zymogenic form that participates in the activation process. The model was constructed based on the 2.3-A-resolution x-ray crystallographic structure of active-site inhibited human FXa (PDB:1XKA). The missing gamma-carboxyglutamic acid (GLA) and part of epidermal growth factor 1 (EGF1) domains of the light chain were modeled based on the template of GLA-EGF1 domains of the tissue factor (TF)-bound FVIIa structure (PDB:1DAN). The activation peptide and other missing segments of FX were introduced using homology modeling. The full calcium-bound model of FX was subjected to 6.2 ns of molecular dynamics simulation in aqueous medium using the AMBER6.0 package. We observed significant reorientation of the serine-protease (SP) domain upon activation leading to a compact multi-domain structure. The solution structure of zymogen appears to be in a well-extended conformation with the distance between the calcium ions in the GLA domain and the catalytic residues estimated to be approximately 95 A in contrast to approximately 83 A in the activated form. The latter is in close agreement with fluorescence studies on FXa. The S1-specificity residues near the catalytic triad show significant differences between the zymogen and activated structures. PMID:11867437

  3. Comparison of coagulants and coagulation aids for treatment of meat processing wastewater by column flotation.

    PubMed

    de Sena, Rênnio F; Moreira, Regina F P M; José, Humberto J

    2008-11-01

    The physicochemical treatment of the wastewater from a meat processing industry was studied using three ferric salts as coagulants in conjunction with four different polymers as coagulation aids by batch column flotation. The effluent was characterized in terms of pH (6.5-6.7), turbidity (1000-12000 NTU), total solids (TS) (2300-7000mgl(-1)), oils and greases (OG) (820-1050mgl(-1)), and biochemical and chemical oxygen demands (BOD(5) and COD) (1200-1760 and 2800-3230mgl(-1)), respectively. The treatments achieved typical organic load reductions of oils and greases, and total solids (up to 85%), as well as biochemical and chemical oxygen demands (between 62.0-78.8% and 74.6-79.5%, respectively). The research also found that the utilization of a column flotation achieved high efficiency of organic matter removal and its operation as a primary treatment showed no significant dependence of pollutant removal and air flow rate.

  4. [Effect of xuebijing oral effervescent tablet on endotoxin induced fever and disseminated intravascular coagulation rabbit model].

    PubMed

    Guo, Shan-Shan; Gao, Ying-Jie; Tian, Xue-Chuan; Jin, Ya-Hong; Liu, Fang-Zhou; Cui, Xiao-Lan

    2013-08-01

    In order to discover the mechanism of Xuebijing oral effervescent tablet (XBJOET) to treat infectious diseases, the effect of XBJOET on endotoxin induced rabbit fever and disseminated intravascular coagulation (DIC) was investigated. Auricle microcirculation in rabbit was detected by laser speckle blood perfusion imager system; coagulation function was measured by coagulation analyzer, fibrinolytic system was quantified by Elisa assay and micro thrombosis in tissues was observed with HE staining under light microscope. The results demonstrated that the body temperature of rabbit decreased significantly at 1-3 h after administration with 4.8, 2.4 and 1.2 g x kg(-1) XBJOET to endotoxin induced DIC rabbit model, the auricle microcirculation blood flow in model group (54.45 +/- 14.53) PU was lower than that in control group (77.18 +/- 12.32) PU. The auricle microcirculation blood flow increased markedly and there was significant difference between model group and 1.2 g x kg(-1) XBJOET group. There was significant difference between model group and control group in the content of PAI1 and FIB. The PAI1 levels in model and control groups were (30.48 +/- 2.46) ng x mL(-1) and (20.93 +/- 3.25) ng x mL(-1), respectively. The FIB levels in model and control group were (3.34 +/- 1.09) g x L(-1) and (4.84 +/- 1.10) g x L(-1), respectively. The content of PAI1 in rabbit plasma decreased notably, there were significant differences between model group and 4.8, 2.4 g x kg(-1) XBJOET groups. On the contrary the content of FIB increased. XBJOET possessed pharmacological activities of curing infectious fever and DIC, the mechanism of which is related to amelioration of microcirculation disturbance, inhibition of fibrinolytic system activation and coagulation and micro thrombosis elimination.

  5. Demonstration of the extrinsic coagulation pathway in teleostei: Identification of zebrafish coagulation factor VII

    PubMed Central

    Sheehan, John; Templer, Michael; Gregory, Michael; Hanumanthaiah, Ravikumar; Troyer, Dean; Phan, Thao; Thankavel, Bharath; Jagadeeswaran, Pudur

    2001-01-01

    It is not known whether the mammalian mechanism of coagulation initiation is conserved in fish. Identification of factor VII is critical in providing evidence for such a mechanism. A cDNA was cloned from a zebrafish (teleost) library that predicted a protein with sequence similarity to human factor VII. Factor VII was shown to be present in zebrafish blood and liver by Western blot analysis and immunohistochemistry. Immunodepletion of factor VII from zebrafish plasma selectively inhibited thromboplastin-triggered thrombin generation. Heterologous expression of zebrafish factor VII demonstrated a secreted protein (50 kDa) that reconstituted thromboplastin-triggered thrombin generation in immunodepleted zebrafish plasma. These results suggest conservation of the extrinsic coagulation pathway between zebrafish and humans and add credence to the zebrafish as a model for mammalian hemostasis. The structure of zebrafish factor VIIa predicted by homology modeling was consistent with the overall three-dimensional structure of human factor VIIa. However, amino acid disparities were found in the epidermal growth factor-2/serine protease regions that are present in the human tissue factor–factor VIIa contact surface, suggesting a structural basis for the species specificity of this interaction. In addition, zebrafish factor VII demonstrates that the Gla-EGF-EGF-SP domain structure, which is common to coagulation factors VII, IX, X, and protein C, was present before the radiation of the teleosts from the tetrapods. Identification of zebrafish factor VII significantly narrows the evolutionary window for development of the vertebrate coagulation cascade and provides insight into the structural basis for species specificity in the tissue factor–factor VIIa interaction. PMID:11459993

  6. Quinine-Induced Disseminated Intravascular Coagulation

    PubMed Central

    2016-01-01

    Every drug comes with some side effect. It is the benefit/risk ratio that determines the medical use of the drug. Quinine, a known antimalarial drug, has been used for nocturnal leg cramps since the 1930s; it is associated with severe life-threatening hematological and cardiovascular side effects. Disseminated intravascular coagulation (DIC), albeit rare, is a known coagulopathy associated with Quinine. It is imperative to inquire about the Quinine intake in medication history in patients with coagulopathy, as most patients still consider it a harmless home remedy for nocturnal leg cramps. In this report, we present a case of coagulopathy in a middle-aged woman, who gave a history of taking Quinine for nocturnal leg cramps, as her home remedy. Early identification of the offending agent led to the diagnosis, prompt discontinuation of the medication, and complete recovery and prevented the future possibility of recurrence. PMID:27293443

  7. Blood and coagulation support in trauma.

    PubMed

    Murthi, Sarah B; Stansbury, Lynn G; Hess, John R

    2009-07-01

    Injury is the leading cause of death in young people and a major cause of loss of years of productive life world wide. Acute surgical care can prevent injury from turning into disability or death but requires prompt access to safe blood products to support resuscitation and restorative surgical procedures. Speed in delivering blood products is critical in resuscitation. Achieving prompt blood product support requires advanced planning and an informed balancing of risks to insure the availability of red cells and coagulation products at the time and place where they are needed. Safety and diagnostic support are critical in the post-resuscitative period where transfusion complications can delay reconstructive surgery and prolong intensive care unit stays. This paper reviews the epidemiology of injury and modern patterns of trauma care against the background of developing knowledge about the coagulopathies of trauma and blood safety.

  8. Optimized alumina coagulants for water treatment

    DOEpatents

    Nyman, May D [Albuquerque, NM; Stewart, Thomas A [Albuquerque, NM

    2012-02-21

    Substitution of a single Ga-atom or single Ge-atom (GaAl.sub.12 and GeAl.sub.12 respectively) into the center of an aluminum Keggin polycation (Al.sub.13) produces an optimal water-treatment product for neutralization and coagulation of anionic contaminants in water. GaAl.sub.12 consistently shows .about.1 order of magnitude increase in pathogen reduction, compared to Al.sub.13. At a concentration of 2 ppm, GaAl.sub.12 performs equivalently to 40 ppm alum, removing .about.90% of the dissolved organic material. The substituted GaAl.sub.12 product also offers extended shelf-life and consistent performance. We also synthesized a related polyaluminum chloride compound made of pre-hydrolyzed dissolved alumina clusters of [GaO.sub.4Al.sub.12(OH).sub.24(H.sub.2O).sub.12].sup.7+.

  9. Management of coagulation abnormalities in liver disease.

    PubMed

    Potze, Wilma; Porte, Robert J; Lisman, Ton

    2015-01-01

    Liver disease is characterized by changes in all phases of hemostasis. These hemostatic alterations were long considered to predispose patients with liver disease towards a bleeding tendency, as they are associated with prolonged conventional coagulation tests. However, these patients may also suffer from thrombotic complications, and we now know that the hemostatic system in patient with liver disease is, in fact, in a rebalanced state. In this review we discuss the concept of rebalanced hemostasis and its implications for clinical management of patients with liver disease. For instance, there is no evidence that the use of prophylactic blood product transfusion prior to invasive procedures reduces bleeding risk. Clinicians should also be aware of the possibility of thrombosis occurring in patients with a liver disease, and regular thrombosis prophylaxis should not be withheld in these patients.

  10. Coagulation fibrinolysis in sickle-cell disease

    PubMed Central

    Gordon, P. A.; Breeze, G. R.; Mann, J. R.; Stuart, J.

    1974-01-01

    A study of fibrinolytic activity in sickle-cell patients during asymptomatic periods has shown a normal fibrinolytic response to exercise and local heat to the arm. During vasoocclusive crises there was no significant decrease in fibrinolytic activity. These results contrast with earlier reports of decreased fibrinolysis during crisis and a suggestion that fibrinolytic activators might be of value in preventing vasoocclusive episodes. Patients in painful crisis showed a significant rise in fibrinogen concentration and fall in platelet count. The former may contribute to localized vascular sludging by increasing whole-blood viscosity, while the latter probably results from local trapping of platelets in areas of sickling or from subsequent splenic sequestration of damaged platelets. There was no evidence of disseminated, as opposed to localized, intravascular coagulation during crisis. PMID:4412492

  11. Contact activation of blood-plasma coagulation

    NASA Astrophysics Data System (ADS)

    Golas, Avantika

    Surface engineering of biomaterials with improved hemocompatibility is an imperative, given the widespread global need for cardiovascular devices. Research summarized in this dissertation focuses on contact activation of FXII in buffer and blood plasma frequently referred to as autoactivation. The extant theory of contact activation imparts FXII autoactivation ability to negatively charged, hydrophilic surfaces. According to this theory, contact activation of plasma involves assembly of proteins comprising an "activation complex" on activating surfaces mediated by specific chemical interactions between complex proteins and the surface. This work has made key discoveries that significantly improve our core understanding of contact activation and unravel the existing paradigm of plasma coagulation. It is shown herein that contact activation of blood factor XII (FXII, Hageman factor) in neat-buffer solution exhibits a parabolic profile when scaled as a function of silanized-glass-particle activator surface energy (measured as advancing water adhesion tension t°a=g° Iv costheta in dyne/cm, where g°Iv is water interfacial tension in dyne/cm and theta is the advancing contact angle). Nearly equal activation is observed at the extremes of activator water-wetting properties --36 < t°a < 72 dyne/cm (O° ≤ theta < 120°), falling sharply through a broad minimum within the 20 < t°a < 40 dyne/cm (55° < theta < 75°). Furthermore, contact activation of FXII in buffer solution produces an ensemble of protein fragments exhibiting either procoagulant properties in plasma (proteolysis of blood factor XI or prekallikrein), amidolytic properties (cleavage of s-2302 chromogen), or the ability to suppress autoactivation through currently unknown biochemistry. The relative proportions of these fragments depend on activator surface chemistry/energy. We have also discovered that contact activation is moderated by adsorption of plasma proteins unrelated to coagulation through an

  12. [The effects of FUT-175 (nafamostat mesilate) on blood coagulation and experimental disseminated intravascular coagulation (DIC)].

    PubMed

    Koshiyama, Y; Kobori, A; Ogihara, M; Yokomoto, Y; Ohtani, K; Shimamura, K; Iwaki, M

    1987-12-01

    FUT-175 is a newly synthesized serine protease inhibitor. In the present study, we investigated the effects of FUT-175 on blood coagulation and experimental DIC. The effects on coagulation were examined in vitro by measuring the activated partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT) of rat plasma in the presence of FUT-175. FUT-175 exhibited remarkable anticoagulative effects to prolong APTT at a plasma concentration of 3 x 10(-7) M, PT at 1 x 10(-5) M and TT at 3 x 10(-5) M. The anticoagulative effect of FUT-175 at 1 x 10(-6) M on APTT was almost similar to that of heparin at 0.3 U/ml or that of gabexate mesilate at 1 x 10(-3) M. Experimental DIC was induced by a four-hr sustained intravenous infusion of endotoxin. FUT-175 was administered intraperitoneally prior to the injection of endotoxin or infused intravenously with endotoxin. As a result, the prolongation of APTT and PT, the decreases of fibrinogen level, platelet counts and complement level, and the increase of FDP were remarkably improved by FUT-175. Furthermore, glomerular fibrin deposits were reduced by the infusion of FUT-175. These results indicate that FUT-175, having a potent inhibitory effect on blood coagulation, is clinically applicable to therapy for DIC.

  13. Local Recurrence After Hepatic Radiofrequency Coagulation

    PubMed Central

    Mulier, Stefaan; Ni, Yicheng; Jamart, Jacques; Ruers, Theo; Marchal, Guy; Michel, Luc

    2005-01-01

    Objective: The purpose of this study was to analyze the factors that influence local recurrence after radiofrequency coagulation of liver tumors. Summary Background Data: Local recurrence rate varies widely between 2% and 60%. Apart from tumor size as an important risk factor for local recurrence, little is known about the impact of other factors. Methods: An exhaustive literature search was carried out for the period from January 1, 1990 to January 1, 2004. Only series with a minimal follow-up of 6 months and/or mean follow-up of 12 months were included. Univariate and multivariate meta-analyses were carried out. Results: Ninety-five independent series were included, allowing the analysis of the local recurrence rate of 5224 treated liver tumors. In a univariate analysis, tumor-dependent factors with significantly less local recurrences were: smaller size, neuroendocrine metastases, nonsubcapsular location, and location away from large vessels. Physician-dependent favorable factors were: surgical (open or laparoscopic) approach, vascular occlusion, general anesthesia, a 1-cm intentional margin, and a greater physician experience. In a multivariate analysis, significantly less local recurrences were observed for small size (P < 0.001) and a surgical (versus percutaneous) approach (P < 0.001). Conclusions: Radiofrequency coagulation by laparoscopy or laparotomy results in superior local control, independent of tumor size. The percutaneous route should mainly be reserved for patients who cannot tolerate a laparoscopy or laparotomy. The short-term benefits of less invasiveness for the percutaneous route do not outweigh the longer-term higher risk of local recurrence. PMID:16041205

  14. Field-theory methods in coagulation theory

    SciTech Connect

    Lushnikov, A. A.

    2011-08-15

    Coagulating systems are systems of chaotically moving particles that collide and coalesce, producing daughter particles of mass equal to the sum of the masses involved in the respective collision event. The present article puts forth basic ideas underlying the application of methods of quantum-field theory to the theory of coagulating systems. Instead of the generally accepted treatment based on the use of a standard kinetic equation that describes the time evolution of concentrations of particles consisting of a preset number of identical objects (monomers in the following), one introduces the probability W(Q, t) to find the system in some state Q at an instant t for a specific rate of transitions between various states. Each state Q is characterized by a set of occupation numbers Q = (n{sub 1}, n{sub 2}, ..., n{sub g}, ...), where n{sub g} is the total number of particles containing precisely g monomers. Thereupon, one introduces the generating functional {Psi} for the probability W(Q, t). The time evolution of {Psi} is described by an equation that is similar to the Schroedinger equation for a one-dimensional Bose field. This equation is solved exactly for transition rates proportional to the product of the masses of colliding particles. It is shown that, within a finite time interval, which is independent of the total mass of the entire system, a giant particle of mass about the mass of the entire system may appear in this system. The particle in question is unobservable in the thermodynamic limit, and this explains the well-known paradox of mass-concentration nonconservation in classical kinetic theory. The theory described in the present article is successfully applied in studying the time evolution of random graphs.

  15. The coagulation profile of preterm delivery.

    PubMed

    Keren-Politansky, Anat; Breizman, Tatiana; Brenner, Benjamin; Sarig, Galit; Drugan, Arieh

    2014-04-01

    Hypercoagulation was suggested to be involved in preterm birth etiology; however, the coagulation state of preterm parturients remains unelucidated. The study aim was to evaluate the haemostatic system of pregnant women with premature uterine contractions (PUC). The cohort study population consisted of 76 healthy pregnant women admitted with regular PUC. The study group included 38 women who experienced preterm birth; 14 of them had preterm premature rupture of membranes (PPROM). The control group included 38 women who eventually had term delivery. Groups were matched for maternal age, number of births and gestational age at admission. Blood samples were tested for haemostatic parameters and coagulation activation markers. Significantly shorter PT and aPTT were documented in the study compared to control group (25.7±2 vs. 27.4±2.7seconds, P=0.003, and 9.96±0.5 vs. 10.1±0.4seconds, P=0.05, respectively), although differences in absolute values were small. There was no significant difference between the two groups in levels of: fibrinogen, D-dimer, protein C-global, free protein S antigen, factor VIII activity, Von Willebrand factor, plasminogen activator inhibitor-1, prothrombin fragments F1+2 (PT F1+2), tissue factor and tissue factor pathway inhibitor. Women with PPROM had significantly lower PT F1+2 levels compared to those who had preterm delivery with intact membranes (351±99 vs. 561±242pmol/L, P=0.003). Shortened PT and aPTT, reflecting increased thrombotic activity in maternal plasma, could serve as a marker of real preterm labor in women with premature uterine contractions. Further prospective studies in a larger cohort are warranted to validate these findings. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. THE TISSUE FACTOR REQUIREMENT IN BLOOD COAGULATION

    PubMed Central

    Orfeo, Thomas; Butenas, Saulius; Brummel-Ziedins, Kathleen E.; Mann, Kenneth G.

    2005-01-01

    Formation of thrombin is triggered when membrane-localized tissue factor (TF) is exposed to blood. In closed models of this process, thrombin formation displays an initiation phase (low rates of thrombin production cause platelet activation and fibrinogen clotting), a propagation phase (>95% of thrombin production occurs) and a termination phase (prothrombin activation ceases and free thrombin is inactivated). A current controversy centers on whether the TF stimulus requires supplementation from a circulating pool of blood TF in order to sustain an adequate procoagulant response. We have evaluated the requirement for TF during the progress of the blood coagulation reaction and have extended these analyses to assess the requirement for TF during resupply (“flow replacement”). Elimination of TF activity at various times during the initiation phase indicated: a period of absolute dependence (<10s); a transitional period in which the dependence on TF is partial and decreases as the reaction proceeds (10–240s); and a period in which the progress of the reaction is TF independent (>240s). Resupply of reactions late during the termination phase with fresh reactants, but no TF, yielded immediate bursts of thrombin formation similar in magnitude to the original propagation phases. Our data show that independence from the initial TF stimulus is achieved by the onset of the propagation phase and that the ensemble of coagulation products and intermediates which yield this TF independence maintain their prothrombin-activating potential for considerable time. These observations support the hypothesis that the transient, localized expression of TF is sufficient to sustain a TF-independent procoagulant response as long as flow persists. PMID:16215234

  17. The tissue factor requirement in blood coagulation.

    PubMed

    Orfeo, Thomas; Butenas, Saulius; Brummel-Ziedins, Kathleen E; Mann, Kenneth G

    2005-12-30

    Formation of thrombin is triggered when membrane-localized tissue factor (TF) is exposed to blood. In closed models of this process, thrombin formation displays an initiation phase (low rates of thrombin production cause platelet activation and fibrinogen clotting), a propagation phase (>95% of thrombin production occurs), and a termination phase (prothrombin activation ceases and free thrombin is inactivated). A current controversy centers on whether the TF stimulus requires supplementation from a circulating pool of blood TF to sustain an adequate procoagulant response. We have evaluated the requirement for TF during the progress of the blood coagulation reaction and have extended these analyses to assess the requirement for TF during resupply ("flow replacement"). Elimination of TF activity at various times during the initiation phase indicated: a period of absolute dependence (<10 s); a transitional period in which the dependence on TF is partial and decreases as the reaction proceeds (10-240 s); and a period in which the progress of the reaction is TF independent (>240 s). Resupply of reactions late during the termination phase with fresh reactants, but no TF, yielded immediate bursts of thrombin formation similar in magnitude to the original propagation phases. Our data show that independence from the initial TF stimulus is achieved by the onset of the propagation phase and that the ensemble of coagulation products and intermediates that yield this TF independence maintain their prothrombin activating potential for considerable time. These observations support the hypothesis that the transient, localized expression of TF is sufficient to sustain a TF-independent procoagulant response as long as flow persists.

  18. Comparative experimental study of argon plasma and bipolar coagulation techniques.

    PubMed

    Riegel, T; Tirakotai, W; Mennel, H D; Hellwig, D; Sure, U; Bertalanffy, H; Celik, I

    2006-07-01

    Argon plasma coagulation (APC) is based on the principle of ionised argon creating conductive plasma between an activating electrode and tissue surface and is used as an effective alternative coagulation technique in various surgical disciplines. This trial aims to compare thermal injury in rat brain caused by APC and conventional bipolar coagulation technique. A controlled study design with constant power setting and application time was established. Twenty rats were randomised into the APC and bipolar groups. Each group of ten rats had 20 treated lesions. Early and late histopathological changes, as well as maximum extent of the lesion after 48 hours (h) and 12 days were studied in overall 20 lesions. Although the maximum depth of the lesions was different in APC (2.2 mm) and bipolar (1.8 mm) groups after 48 h, this did not achieve statistical significance (p=0.151). The superficially coagulated area was significantly larger after APC compared with the bipolar technique at the 48 h time point (p=0.032). After twelve days there were no differences in penetration depth (p=0.310) or coagulated area (p=0.222). Tissue defects after APC application on rat brains were comparable to conventional bipolar technique in this trial. The results suggest that argon plasma coagulation (APC) is an effective coagulation technique.

  19. A short contemporary history of disseminated intravascular coagulation.

    PubMed

    Levi, Marcel; van der Poll, Tom

    2014-11-01

    Disseminated intravascular coagulation (DIC) is a syndrome characterized by systemic intravascular activation of coagulation, leading to a widespread deposition of fibrin in the circulation. There is ample experimental and pathological evidence that the fibrin deposition contributes to multiple organ failure. The massive and ongoing activation of coagulation may result in depletion of platelets and coagulation factors, which may cause bleeding (consumption coagulopathy). The syndrome of DIC is well known in the medical literature for centuries, although a more precise description of the underlying mechanisms had to await the 20th century. Initial ideas on a role of the contact activation system as the primary trigger for the systemic activation of coagulation as well as a presumed hyperfibrinolytic response in DIC have been found to be misconceptions. Experimental and clinical evidence now indicate that the initiation of coagulation in DIC is caused by tissue factor expression, which in combination with downregulated physiological anticoagulant pathways and impaired fibrinolysis leads to widespread fibrin deposition. In addition, an extensive bidirectional interaction between coagulation and inflammation may further contribute to the pathogenesis of DIC.

  20. Nanoparticles and the blood coagulation system. Part II: safety concerns.

    PubMed

    Ilinskaya, Anna N; Dobrovolskaia, Marina A

    2013-06-01

    Nanoparticle interactions with the blood coagulation system can be beneficial or adverse depending on the intended use of a nanomaterial. Nanoparticles can be engineered to be procoagulant or to carry coagulation-initiating factors to treat certain disorders. Likewise, they can be designed to be anticoagulant or to carry anticoagulant drugs to intervene in other pathological conditions in which coagulation is a concern. An overview of the coagulation system was given and a discussion of a desirable interface between this system and engineered nanomaterials was assessed in part I, which was published in the May 2013 issue of Nanomedicine. Unwanted pro- and anti-coagulant properties of nanoparticles represent significant concerns in the field of nanomedicine, and often hamper the development and transition into the clinic of many promising engineered nanocarriers. This part will focus on the undesirable effects of engineered nanomaterials on the blood coagulation system. We will discuss the relationship between the physicochemical properties of nanoparticles (e.g., size, charge and hydrophobicity) that determine their negative effects on the blood coagulation system in order to understand how manipulation of these properties can help to overcome unwanted side effects.

  1. Nanoparticles and the blood coagulation system. Part II: safety concerns

    PubMed Central

    Ilinskaya, Anna N; Dobrovolskaia, Marina A

    2014-01-01

    Nanoparticle interactions with the blood coagulation system can be beneficial or adverse depending on the intended use of a nanomaterial. Nanoparticles can be engineered to be procoagulant or to carry coagulation-initiating factors to treat certain disorders. Likewise, they can be designed to be anticoagulant or to carry anticoagulant drugs to intervene in other pathological conditions in which coagulation is a concern. An overview of the coagulation system was given and a discussion of a desirable interface between this system and engineered nanomaterials was assessed in part I, which was published in the May 2013 issue of Nanomedicine. Unwanted pro- and anti-coagulant properties of nanoparticles represent significant concerns in the field of nanomedicine, and often hamper the development and transition into the clinic of many promising engineered nanocarriers. This part will focus on the undesirable effects of engineered nanomaterials on the blood coagulation system. We will discuss the relationship between the physicochemical properties of nanoparticles (e.g., size, charge and hydrophobicity) that determine their negative effects on the blood coagulation system in order to understand how manipulation of these properties can help to overcome unwanted side effects. PMID:23730696

  2. The emerging role of coagulation proteases in kidney disease

    PubMed Central

    Madhusudhan, Thati; Kerlin, Bryce A.; Isermann, Berend

    2016-01-01

    A role of coagulation proteases in kidney disease beyond their function in normal haemostasis and thrombosis has long been suspected, and studies performed in the past 15 years have provided novel insights into the mechanisms involved. The expression of protease-activated receptors (PARs) in renal cells provides a molecular link between coagulation proteases and renal cell function and revitalizes research evaluating the role of haemostasis regulators in renal disease. Renal cell-specific expression and activity of coagulation proteases, their regulators and their receptors are dynamically altered during disease processes. Furthermore, renal inflammation and tissue remodelling are not only associated, but are causally linked with altered coagulation activation and protease-dependent signalling. Intriguingly, coagulation proteases signal through more than one receptor or induce formation of receptor complexes in a cell-specific manner, emphasizing context specificity. Understanding these cell-specific signalosomes and their regulation in kidney disease is crucial to unravelling the pathophysiological relevance of coagulation regulators in renal disease. In addition, the clinical availability of small molecule targeted anticoagulants as well as the development of PAR antagonists increases the need for in-depth knowledge of the mechanisms through which coagulation proteases might regulate renal physiology. PMID:26592189

  3. Implementation of a microcontroller-based semi-automatic coagulator.

    PubMed

    Chan, K; Kirumira, A; Elkateeb, A

    2001-01-01

    The coagulator is an instrument used in hospitals to detect clot formation as a function of time. Generally, these coagulators are very expensive and therefore not affordable by a doctors' office and small clinics. The objective of this project is to design and implement a low cost semi-automatic coagulator (SAC) prototype. The SAC is capable of assaying up to 12 samples and can perform the following tests: prothrombin time (PT), activated partial thromboplastin time (APTT), and PT/APTT combination. The prototype has been tested successfully.

  4. Pro-coagulant activity of human mesenchymal stem cells.

    PubMed

    Christy, Barbara A; Herzig, Maryanne C; Montgomery, Robbie K; Delavan, Christopher; Bynum, James A; Reddoch, Kristin M; Cap, Andrew P

    2017-04-05

    Allogeneic mesenchymal stem cells (MSCs) show great potential for the treatment of military and civilian trauma, based on their reduced immunogenicity and ability to modulate inflammation and immune function in the recipient. Although generally considered to be safe, MSCs express tissue factor (TF), a potent activator of coagulation. In the current study, we evaluated multiple MSC populations for tissue factor expression and pro-coagulant activity in order to characterize safety considerations for systemic use of MSCs in trauma patients who may have altered coagulation homeostasis. Multiple MSC populations derived from either human adipose tissue or bone marrow were expanded in the recommended stem cell media. Stem cell identity was confirmed using a well-characterized panel of positive and negative markers. Tissue factor expression on the cell surface was evaluated by flow cytometry with anti-CD142 antibody. Effects on blood coagulation were determined by thromboelastography (TEG) and calibrated automated thrombogram (CAT) assays using platelet poor plasma or whole blood. MSCs express tissue factor on their surfaces and are pro-coagulant in the presence of blood or plasma. The adipose-derived MSCs (Ad-MSC) evaluated were more pro-coagulant and expressed more tissue factor than bone marrow MSCs (BM-MSCs), which showed a greater variability in TF expression. BM-MSCs were identified that exhibited low pro-coagulant activity, whereas all Ad-MSCs examined exhibited high pro-coagulant activity. The percentage of cells in a given population expressing surface tissue factor correlates roughly with functional pro-coagulant activity. MSC tissue factor expression and pro-coagulant activity change over time in culture. All MSC populations are not equivalent; care should be taken to select cells for clinical use that minimize potential safety problems and maximize chance of patient benefit. Adipose-derived MSCs appear more consistently pro-coagulant than BM-MSCs, presenting a

  5. Argon laser photo-coagulation complications in diabetic retinopathy.

    PubMed

    Pavljasević, Suzana; Pranjić, Nurka; Sarajlić, Dzevdet

    2004-05-01

    Diabetic retinopathy is a disease based on vascular genesis that begins as microangiopathy and develops into macroangioapthy preceded by fibroproliferation changes. According to histo- pathological changes, diabetic retinopathy is divided into nonproliferative, pre-proliferative and proliferative diabetic retinopathy. Possibilities and needs for photo-coagulation in the earlier and later changes in retina reduce the meaning of conservative treatment. Laser photo-coagulation with therapeutical may cause unwanted and damaging effects, as well. Complications diagnosed in diabetic retinopathy, such as cataract, secondary glaucoma, central retinal vein thrombosis, haemophthalmus, are much more frequent in patients with laser photo-coagulation treatment.

  6. Changes in the human blood coagulating system during prolonged hypokinesia

    NASA Technical Reports Server (NTRS)

    Filatova, L. M.; Anashkin, O. D.

    1978-01-01

    Changes in the coagulating system of the blood were studied in six subjects during prolonged hypokinesia. Thrombogenic properties of the blood rose in all cases on the 8th day. These changes are explained by stress reaction due to unusual conditions for a healthy person. Changes in the blood coagulating system in the group subjected to physical exercise and without it ran a practically parallel course. Apparently physical exercise is insufficient to prevent such changes that appear in the coagulating system of the blood during prolonged hypokinesia.

  7. Influence of Enteromorpha polysaccharides on variation of coagulation behavior, flocs properties and membrane fouling in coagulation-ultrafiltration process.

    PubMed

    Zhao, Shuang; Gao, Baoyu; Yue, Qinyan; Sun, Shenglei; Song, Wuchang; Jia, Ruibao

    2015-03-21

    Enteromorpha polysaccharides (Ep) were used as a new coagulant aid together with polyaluminum chloride (PACl) in coagulation-ultrafiltration process to purify Yellow River water. The evolution of flocs size, growth rate, strength, recoverability and fractal structure due to Ep addition were systematically studied in this paper. On this basis, membrane fouling caused by the coagulation effluents of PACl and Ep were also investigated. Results indicated that Ep addition lead to 20% increase in coagulation performance, and meanwhile generate flocs with bigger sizes, faster growth rates and higher recovery abilities. Additionally, the flocs formed by PACl presented more compact structure with a larger D(f) value, while much looser flocs were obtained when Ep was added. Results of ultrafiltration experiments implied that with Ep addition, membrane fouling could be significantly reduced due to large size and loosely structures of flocs in coagulation effluents. Considering both the coagulation efficiency and ultrafiltration membrane performance, 0.2 mg/L Ep was determined as the optimal dosage in coagulation-ultrafiltration process in this study.

  8. Removal of titanium dioxide nanoparticles by coagulation: effects of coagulants, typical ions, alkalinity and natural organic matters.

    PubMed

    Wang, H T; Ye, Y Y; Qi, J; Li, F T; Tang, Y L

    2013-01-01

    To investigate the possibility of removing titanium dioxide nanoparticles (TiO2 NPs) from water by coagulation, as well as to find the optimal coagulant and experimental conditions for TiO2 NP removal, four types of coagulant were adopted: polyferric sulfate (PFS), ferric chloride (FeCl3), polyaluminum chloride (PACl), and alum (Al2(SO4)3). It was found that the removal of TiO2 NPs by coagulation was affected by ionic strength, alkalinity, as well as types and dosages of coagulants. PFS and FeCl3 achieved much higher removal efficiency of TiO2 NPs than PACl and Al2(SO4)3 did. For 30 mg/L TiO2 NPs, a dosage of 0.3 mM PFS (as Fe) achieved 84% removal after coagulation followed by 30 min settlement. Optimal ionic strength (0.1 M NaCl or 0.03 M CaCl2) is of vital importance for the performance of PFS. Na2SO4 is unfavorable for the performance of PFS. Optimal alkalinity (0.01-0.03 M NaHCO3) is necessary for FeCl3 to remove TiO2 NPs. Natural organic matter, as represented by humic acid (HA) up to 11 mg/L, reduces the removal of TiO2 NPs by coagulation. These findings indicate that coagulation is a good option for the removal of TiO2 NPs from water, and more attention should be paid to the effects of water quality when using coagulation to remove TiO2 NPs from aqueous matrices. This provides a possible solution to alleviate the potential hazard caused by TiO2 NPs.

  9. Effect of copper(II) on natural organic matter removal during drinking water coagulation using aluminum-based coagulants.

    PubMed

    Liu, Guojing; Zhang, Xiangru; Talley, Jeffrey W

    2007-06-01

    Coagulation has been proposed as a best available technology for controlling natural organic matter (NOM) during drinking water treatment. The presence of heavy metals such as copper(II) in source water, which may form copper-NOM complexes and/or interact with a coagulant, may pose a potential challenge on the coagulation of NOM. In this work, the effect of copper(II) on NOM removal by coagulation using alum or PAX-18 (a commercial polymerized aluminum chloride from Kemiron Inc., Bartow, Florida) was examined. The results show that the presence of 1 to 10 mg/L of copper(H) in the simulated waters improved the total organic carbon (TOC) removal by up to 25% for alum coagulation and by up to 22% for PAX-18 coagulation. The increased NOM removal with the presence of copper(II) in the waters can most likely be ascribed to the formation copper-NOM complexes that may be more adsorbable on aluminum precipitates and to the formation of copper(II) co-precipitates that may also adsorb NOM. The presence of 1 to 5 mg/L of copper(I) in the waters containing 3 mg/L NOM as carbon was reduced below the maximum contaminant level goal (1.3 mg/L as copper) using either coagulant. The results suggest that the presence of copper(H) in source water may not adversely affect the NOM removal by coagulation. A good linear correlation was observed between the TOC removal efficiency and the log-total moles of the precipitated metals, which include the metal ion from a coagulant and the divalent metal ion(s) in source water.

  10. Influence of natural coagulants on isoflavones and antioxidant activity of tofu.

    PubMed

    Rekha, C R; Vijayalakshmi, G

    2010-08-01

    Tofu (instead of preparing using synthetic coagulant) was prepared using coagulants of plant origin (Citrus limonum, Garcinia indica, Tamarindus indica, Phyllanthus acidus and Passiflora edulis). Total crude protein and fat contents were highest in tofu prepared using G. indica and T. indica (72.5% dbw) compared to synthetic coagulant. Tofu prepared with natural coagulants had signifi cantly higher antioxidant activity compared to synthetic coagulant. Bioconversion of isoflavone glucosides (daidzin and genistin) into their corresponding bioactive aglycones (daidzein and genistein) was observed in tofu. The difference between glucosides and aglycones contents in soy milk was significant but there was not much difference in tofu coagulated with synthetic and natural coagulants.

  11. Impacts of epichlorohydrin-dimethylamine on coagulation performance and membrane fouling in coagulation/ultrafiltration combined process with different Al-based coagulants.

    PubMed

    Bu, Fan; Gao, Baoyu; Li, Ruihua; Sun, Shenglei; Yue, Qinyan

    2016-09-01

    Two kinds of aluminum-based coagulants and epichlorohydrin-dimethylamine (DAM-ECH) were used in the treatment of humic acid-kaolin simulated water by coagulation-ultrafiltration (C-UF) hybrid process. Coagulation performance, floc characteristics, including floc size, compact degree, and strength were investigated in this study. Ultrafiltration experiments were conducted by a dead-end batch unit to implement the resistance analyses to explore the membrane fouling mechanisms. Results showed that DAM-ECH aid significantly increased the UV254 and DOC removal efficiencies and contributed to the formation of larger and stronger flocs with a looser structure. Aluminum chloride (Al) gave rise to better coagulation performance with DAM-ECH compared with poly aluminum chloride (PACl). The consequences of ultrafiltration experiments showed that DAM-ECH aid could reduce the membrane fouling mainly by decreasing the cake layer resistance. The flux reductions for PACl, Al/DAM-ECH (dosing both Al and DAM-ECH) and PACl/DAM-ECH (dosing both PACl and DAM-ECH) were 62%, 56% and 44%, respectively. Results of this study would be beneficial for the application of PACl/DAM-ECH and Al/DAM-ECH composite coagulants in water treatment processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. CARDIOVASCULAR AND BLOOD COAGULATION EFFECTS OF PULMONARY ZINC EXPOSURE

    EPA Science Inventory

    Cardiovascular damage induced by pulmonary exposure to environmental chemicals can result from direct action or, secondarily, from pulmonary injury. We have developed a rat model of pulmonary exposure to zinc to demonstrate cardiac, coagulative, and fibrinolytic alterations. Mal...

  13. Surgical Coagulator With Carbon Dioxide Laser For Gynecology

    NASA Astrophysics Data System (ADS)

    Wolinski, Wieslaw; Kazmirowski, Antoni; Korobowicz, Witold; Olborski, Zbigniew

    1987-10-01

    The technical data and parameters of the CO2 surgical laser for gynecology are given. Coagulator was designed and constructed in Institute of Microelectronics and Optoelectronics Warsaw Technical University.

  14. Screening for coagulation disorders in patients with ischemic stroke.

    PubMed

    de Lau, Lonneke Ml; Leebeek, Frank Wg; de Maat, Moniek Pm; Koudstaal, Peter J; Dippel, Diederik Wj

    2010-08-01

    The role of coagulation disorders in the pathogenesis of (recurrent) ischemic stroke is uncertain. Therefore, the clinical utility of screening patients with ischemic stroke for these conditions and the therapeutic implications of a detected coagulation disorder in a patient who experienced ischemic stroke are uncertain. We reviewed the currently available data on the relationship between various inherited and acquired coagulation abnormalities (factor V Leiden and prothrombin G20210A mutations, deficiencies of protein C, protein S and anti-thrombin, hyperhomocysteinemia, the antiphospholipid syndrome and increased levels of fibrinogen) and ischemic stroke. Based on the existing evidence we discuss the usefulness of screening stroke patients for prothrombotic conditions and current recommendations regarding the optimal management of ischemic stroke patients in whom a coagulation disorder is found.

  15. CARDIOVASCULAR AND BLOOD COAGULATION EFFECTS OF PULMONARY ZINC EXPOSURE

    EPA Science Inventory

    Cardiovascular damage induced by pulmonary exposure to environmental chemicals can result from direct action or, secondarily, from pulmonary injury. We have developed a rat model of pulmonary exposure to zinc to demonstrate cardiac, coagulative, and fibrinolytic alterations. Mal...

  16. Electro-coagulation treatment of oily wastewater with sludge analysis.

    PubMed

    Ibrahim, Dhorgham Skban; Sakthipriya, N; Balasubramanian, N

    2012-01-01

    Experiments were carried out in a batch reactor to treat the oily effluent by electro-coagulation. The influence of operating parameters such as applied current, type of electrode and electrolysis time on electro-coagulation efficiency has been critically examined. The maximum percentage removal of chemical oxygen demand (COD) was 94% under optimum experimental conditions of pH 6.7, current density 6 mA/cm², electrolysis time 40 min, and using mild steel as anode. The remaining sludge in the reactor was analyzed by energy disperse analysis of X-rays (EDAX) and scanning electron microscope (SEM) analysis. The analysis confirms that the oily pollutant was removed by electroflotation and adsorption of the oily particles of precipitate during the electro-coagulation process. Electro-coagulation can be used as an efficient treatment technique for oily wastewater.

  17. Carbon dioxide pressure-induced coagulation of microalgae.

    PubMed

    Lee, Roland; Jessop, Philip G; Champagne, Pascale

    2015-12-28

    The move to a low-carbon economy has generated renewed interest in microalgae for the production of biofuels with the potential mutual benefit of wastewater treatment. However, harvesting has been identified as a limiting factor to the economic viability of this process. This paper explores the harvesting of microalgae using high-pressure gas without the addition of coagulants. Coagulation of microalgae under high-pressure gas was found to be an efficient method to separate algae from suspension. The critical coagulation pressures (CCPs) for H(2) and CO(2) were determined to be 6.1 and 6.2 MPa, respectively. The CO(2)-induced decrease in solution pH positively influenced coagulation rates, without appearing to affect the CCP. This approach could be beneficial for the economic removal of microalgae from solution for the production of both biofuels and biomedical compounds without the addition of non-environmentally friendly chemicals.

  18. Disseminated intravascular coagulation: a review for the internist.

    PubMed

    Levi, Marcel; van der Poll, Tom

    2013-02-01

    Disseminated intravascular coagulation (DIC) is a syndrome characterized by systemic intravascular activation of coagulation, leading to widespread deposition of fibrin in the circulation. Recent knowledge on important pathogenetic mechanisms that may lead to DIC has resulted in novel preventive and therapeutic approaches to patients with DIC. The diagnosis of DIC can be made by sensitive laboratory tests; however, most of these tests are not readily available in a clinical setting. A reliable diagnosis can also be made on the basis of a small series of laboratory tests that can be combined in a scoring algorithm. The cornerstone of the management of DIC is the specific and vigorous treatment of the underlying disorder. Strategies aimed at the inhibition of coagulation activation may theoretically be justified and have been found beneficial in experimental and clinical studies. These strategies comprise inhibition of tissue factor-mediated activation of coagulation or restoration of physiological anticoagulant pathways.

  19. Bio-responsive polymer hydrogels homeostatically regulate blood coagulation

    PubMed Central

    Maitz, Manfred F.; Freudenberg, Uwe; Tsurkan, Mikhail V.; Fischer, Marion; Beyrich, Theresa; Werner, Carsten

    2013-01-01

    Bio-responsive polymer architectures can empower medical therapies by engaging molecular feedback-response mechanisms resembling the homeostatic adaptation of living tissues to varying environmental constraints. Here we show that a blood coagulation-responsive hydrogel system can deliver heparin in amounts triggered by the environmental levels of thrombin, the key enzyme of the coagulation cascade, which—in turn—becomes inactivated due to released heparin. The bio-responsive hydrogel quantitatively quenches blood coagulation over several hours in the presence of pro-coagulant stimuli and during repeated incubation with fresh, non-anticoagulated blood. These features enable the introduced material to provide sustainable, autoregulated anticoagulation, addressing a key challenge of many medical therapies. Beyond that, the explored concept may facilitate the development of materials that allow the effective and controlled application of drugs and biomolecules. PMID:23868446

  20. Explanations for coagulation activation after air travel.

    PubMed

    Schreijer, A J M; Hoylaerts, M F; Meijers, J C M; Lijnen, H R; Middeldorp, S; Büller, H R; Reitsma, P H; Rosendaal, F R; Cannegieter, S C

    2010-05-01

    It is unknown whether venous thrombosis after long haul air travel is exclusively attributable to immobilization. We determined whether the following mechanisms were involved: hypoxia, stress, inflammation or viral infection. In a case crossover setting in 71 healthy volunteers who were exposed to an 8-h flight, 8-h movie marathon and 8 h of regular activities, we compared markers for several hypothetical pathways: plasminogen activator inhibitor-1 (PAI-1), stress, plasma factor (F)VIII coagulant activity (FVIIIc), soluble P-selectine (sP-selectine), interleukin-8 (IL-8) and neutrophil elastase. We reported earlier an activated clotting system, as evidenced by thrombin generation, in 17% of volunteers after the flight. PAI-1 increased by 4.2 ng mL(-1) (CI95:-49.5 to 6.5) in volunteers with an activated clotting system whereas it decreased in those without (-20.0 ng mL(-1), CI95:-33.2 to -14.0). FVIIIc levels rose more in individuals with clotting activation (18.0%, CI95:-1.0 to 33.0) than in those without (2.0%, CI95:-2.0 to 5.0). The increases in FVIIIc were not associated with stress, which appeared unrelated to clotting activation. sP-selectin increased in those with clotting activation (3.5 microg L(-1), CI95: -3.0 to 10.0), but decreased in those without (-0.5 microg L(-1), CI95: -2.0 to 2.0). Changes in levels of neutrophil elastase or IL-8 were not different between the subjects with and without clotting activation. Our results do not support the hypotheses that stress, infection or air pollution are involved in the development of a prothrombotic state in air travellers. After long haul air travel, this state is more pronounced in patients with risk factors and may be caused by hypoxia, triggering systemic inflammation and platelet activation, leading to coagulation induction and degranulation of platelets.

  1. PLASMA COAGULATION BY ORGANISMS OTHER THAN STAPHYLOCOCCUS AUREUS.

    PubMed

    BAYLISS, B G; HALL, E R

    1965-01-01

    Bayliss, Berenice G. (Washington State University, Pullman), and Elizabeth R. Hall. Plasma coagulation by organisms other than Staphylococcus aureus. J. Bacteriol. 89:101-105. 1965.-Approximately 200 organisms were investigated for their ability to clot human and rabbit plasma. Various anticoagulants were used in preparing the plasma: acid-citrate-dextrose, ethylenediaminetetraacetate, balanced oxalate, potassium and sodium oxalates, and heparin. Twelve organisms were found which coagulated citrated plasma in less than 8 hr: four strains of Streptococcus faecalis; two strains of S. faecalis var. zymogenes; three strains of S. faecalis var. liquefaciens; and one strain each of S. pyogenes, Escherichia coli, and Serratia marcescens. Six strains of coagulase-positive Staphylococcus were selected for use as controls. Experiments were performed to determine the mechanism by which these microorganisms coagulated citrated plasma. As this was the only plasma clotted, it was presumed that the citrate was utilized by the microorganisms, thereby releasing the calcium which was then made available so that normal physiological clotting could occur. To test this hypothesis, a chromatographic method was employed to determine the presence or absence of citrate. Coagulation tests, by use of increasing amounts of citrate, showed a linear relationship between the amount of citrate in the plasma and the coagulation time. It was demonstrated that the organisms must be actively metabolizing to clot citrated plasma. Proof for this was obtained by using a cell-free filtrate, to which thimerosal had been added to inhibit growth, instead of whole cultures for the coagulation test. Only the coagulase-positive staphylococci coagulated the citrated plasma under these conditions. From the results obtained, it was concluded that plasma coagulation by these organisms was by citrate utilization.

  2. Removal of Arsenic from Drinking Water by Adsorption and Coagulation

    NASA Astrophysics Data System (ADS)

    Zhang, M.; Sugita, H.; Hara, J.; Takahashi, S.

    2013-12-01

    Removal of arsenic from drinking water has been an important issue worldwide, which has attracted greater attentions in recent years especially for supplying safe drinking water in developing countries. Although many kinds of treatment approaches that are available or applicable both in principle and practice, such as adsorption, coagulation, membrane filtration, ion exchange, biological process, electrocoagulation and so on, the first 2 approaches (i.e., adsorption and coagulation) are most promising due to the low-cost, high-efficiency, simplicity of treating systems, and thus can be practically used in developing countries. In this study, a literature survey on water quality in Bangladesh was performed to understand the ranges of arsenic concentration and pH of groundwater in Bangladesh. A series of tests were then organized and performed to investigate the effects of arsenic concentration, arsenic forms, pH, chemical compositions of the materials used for adsorption and coagulation, particle size distribution and treatment time on quality of treated water. The experimental results obtained in the study illustrated that both adsorption and coagulation can be used to effectively reduce the concentrations of either arsenic (V) or arsenic (III) from the contaminated water. Coagulation of arsenic with a magnesium-based material developed in this study can be very effective to remove arsenic, especially arsenic (V), from contaminated water with a concentration of 10 ppm to an undetectable level of 0.002 ppm by ICP analyses. Compared to arsenic (III), arsenic (V) is easier to be removed. The materials used for adsorption and coagulation in this study can remove arsenic (V) up to 9 mg/g and 6 mg/g, and arsenic (III) up to 4 mg/g and 3 mg/g, respectively, depending on test conditions and compositions of the materials being used. The control of pH during treatment can be a challenging technical issue for developing both adsorbent and coagulant. Keywords: Water Treatment

  3. The Continuous Coagulation-FragmentationEquations with Diffusion

    NASA Astrophysics Data System (ADS)

    Laurençot, Philippe; Mischler, Stéphane

    Existence of global weak solutions to the continuous coagulation-fragmentation equations with diffusion is investigated when the kinetic coefficients satisfy a detailed balance condition or the coagulation coefficient enjoys a monotonicity condition. Our approach relies on weak and strong compactness methods in L1 in the spirit of the DiPerna-Lions theory for the Boltzmann equation. Under the detailed balance condition the large-time behaviour is also studied.

  4. Coagulation and flocculation study of iron ore fines

    SciTech Connect

    Singh, B.P.; Besra, L.; Ravi Prasad, A.

    1999-03-01

    A comparative study of the flocculation and coagulation response of an iron ore fines suspension has been carried out, and the extent of flocculation has been assessed by measurement of electrophoretic mobility, supernatant clarity, and settling rate. Of the several commercial flocculants and polyelectrolyte studied, the combination of medium molecular weight anionic flocculants Magnafloc 1011 and Rishfloc 258 (1:1), and coagulant aluminum nitrate was most effective in terms of enhancing settling rate and supernatant clarity.

  5. A new coagulation defect associated with a case of melanomatosis.

    PubMed Central

    Phillips, J D; O'Shea, M J

    1977-01-01

    A marked abnormality of the intrinsic coagulation system was observed in a patient with melanomatosis and frank melanuria. With successful treatment of the tumour there was a parallel improvement in the clotting abnormality. This defect was shown to be a deficiency of factor XI together with a previously unrecognised factor. This is distinct from either Fletcher or Fitzgerald factors and appears to act between factors XI and X in the coagulation sequence. PMID:874111

  6. Reference intervals for common coagulation tests of preterm infants (CME).

    PubMed

    Christensen, Robert D; Baer, Vickie L; Lambert, Diane K; Henry, Erick; Ilstrup, Sarah J; Bennett, Sterling T

    2014-03-01

    Fresh-frozen plasma (FFP) is sometimes administered to nonbleeding preterm neonates who are judged to be at risk for bleeding because they have abnormal coagulation tests. The benefits/risks of this practice are not well defined. One limitation to progress is lack of reference intervals for the common coagulation tests, thus limiting precision about whether coagulation tests are indeed abnormal. In a sequential observational study, fetal blood was drawn at preterm birth (≤ 34 weeks) from the umbilical vein near the placenta. Fibrinogen, prothrombin time, activated partial thromboplastin time, D-dimer, platelet (PLT) count, and mean PLT volume were measured. Reference intervals were constructed using 5th and 95th percentile values. Associations were then sought between abnormal coagulation values at birth and bleeding problems identified during the first week. Coagulation tests were drawn at 175 preterm deliveries and the results were organized into reference intervals by gestational age. No abnormal coagulation value, either alone or in combination, predicted hemorrhage (intraventricular, gastrointestinal, or pulmonary) during the first week. However, fibrinogen exceeding the 95th percentile was associated with evidence of in utero infection/inflammation (correlations with elevated C-reactive protein, p<0.01, and elevated immature to total neutrophil ratio, p<0.001). Abnormal coagulation values at preterm birth do not predict bleeding during the first week. This suggests to us that bleeding in the days after preterm birth is not generally the result of in utero coagulopathy. These findings bring into question the value of coagulation screening of nonbleeding preterm infants and prophylactic FFP administration to those with abnormal values. © 2013 American Association of Blood Banks.

  7. Disequilibrium of Blood Coagulation and Fibrinolytic System in Patients With Coronary Artery Ectasia

    PubMed Central

    Wu, Wei; Liu, Ruifeng; Chen, Lianfeng; Chen, Houzao; Zhang, Shuyang

    2016-01-01

    Abstract Thrombus formation and myocardial infarction are not uncommon in patients with coronary artery ectasia (CAE). In light of this, the present study aims to systemically evaluate the blood coagulation and fibrinolytic systems in CAE patients. In this study, we enrolled 30 patients with CAE, 30 patients with coronary atherosclerosis disease (CAD), and 29 subjects with normal coronary arteries (control). The coagulation system was evaluated using a routine coagulation function test performed in the hospital laboratory before coronary angiography, and measurements included prothrombin time, international normalized ratio, activated partial thromboplastin time, fibrinogen time, and thrombin time. The evaluation of the fibrinolytic system included measurements of D-dimer, euglobulin lysis time, plasminogen activator inhibitor 1, plasminogen, plasminogen activity assay, α1-antitrypsin (α1-AT), α2 plasmin inhibitor (α2-PI), and α2-macroglobulin (α2-MG). Alpha1-AT, α2-PI, and α2-MG also inhibit activities of 3 neutrophil serine proteases, namely human neutrophil elastase (HNE), cathepsin G (CG), and proteinase 3 (PR3); therefore, the plasma levels of these 3 proteinases were also evaluated. In CAE patients, the circulating coagulation system was normal. For the fibrinolytic system, a decrease of plasminogen activity was observed (P = 0.029) when compared with CAD patients, and the concentrations of α1-AT (both P < 0.001), α2-PI (P = 0.002 and P = 0.025), and α2-MG (P = 0.034 and P < 0.001) were significantly elevated when compared with CAD patients and normal controls. Moreover, the plasma levels of HNE (both P < 0.001) and CG (P = 0.027 and 0.016) in CAE patients were also significantly higher than those of the CAD and control groups. There was no difference in plasma PR3 concentration among these 3 groups. Disequilibrium of the coagulation/fibrinolytic system may contribute to thrombus formation and clinical coronary

  8. Effect of rivaroxaban on blood coagulation using the viscoelastic coagulation test ROTEM™.

    PubMed

    Casutt, M; Konrad, C; Schuepfer, G

    2012-11-01

    This study investigated the influence of the oral direct inhibitor of factor Xa rivaroxaban on blood coagulation measured by rotation thrombelastometry ROTEM™. Blood was obtained from 11 healthy male volunteers before and 2.5 h after oral administration of 10 mg rivaroxaban. In addition to standard coagulation tests clot formation was measured by ROTEM™ analyzing extrinsic (Extem) and intrinsic thrombelastometry (Intem). Significant differences to the baseline values were found in the Extem clotting time (Extem-CT, 58 ± 9 s and 87 ± 17 s, p < 0.01), Intem-CT (194 ± 26 s and 239 ± 43 s; p = 0.02), prothrombin time (PT, 86 ± 9% and 67 ± 7%; p < 0.01) and activated partial thromboplastin time (aPTT, 28 ± 1 s and 35 ± 2 s; p < 0.01). There was a low correlation between Extem-CT and PT as well as between Intem-CT and aPTT before and after rivaroxaban intake. The receiver operating characteristic curve (ROC) analysis determined aPTT to be the most appropriate parameter for the prediction of rivaroxaban-induced anticoagulation, Intem-CT and Extem-CT proved to be moderate tests and PT had no significance in the prediction of rivaroxaban-induced anticoagulation. Of utmost clinical importance was the fact that rivaroxaban treated patients could still show normal ROTEM™ values. Thus, ROTEM™ cannot be a suitable test method to exclude inhibition of blood coagulation by rivaroxaban.

  9. Diplazium esculentum leaf extract as coagulant aid in leachate treatment

    NASA Astrophysics Data System (ADS)

    Zainol, Noor Ainee; Aziz, Hamidi Abdul; Lutpi, Nabilah Aminah

    2017-04-01

    The use of extracts from Diplazium esculentum leaves as coagulant and coagulant aid has not been discussed in literature. In this research, the capability of extracts from D. esculentum leaves, namely, D. esculentum aqueous (DEaqs) and D. esculentum powder (DEpowd), to act as coagulant aid in combination with polyaluminum chloride (PACl) was evaluated using stabilized leachate from the Kuala Sepetang Landfill Site (KSLS) and the Kulim Landfill Site (KLS) through a Jar test. Identified as polymers with high molecular weight, DEaqs (221 kDa) and DEpowd (275 kDa) act as anionic coagulants and are capable of promoting the coagulation process in leachate saturated with negative particles. The main functional groups that induce the coagulation-flocculation process by DEaqs and DEpowd are carboxyl, hydroxyl, and amine groups, which all contain hydrogen in their molecules. Jar test results were analyzed based on the removal efficiency (RE) of suspended solids (SS), turbidity, colour, chemical oxygen demand (COD), and ammonia-N. A 50% reduction in the volume of PACl from its optimum dosage, with the DEaqs and DEpowd dosages below 1000 mg/L, exhibited a synergic effect of all the measured parameters in KSLS leachates.

  10. Coagulation-flocculation in leachate treatment using modified micro sand

    NASA Astrophysics Data System (ADS)

    Thaldiri, Nur Hanani; Halim, Azhar Abdul

    2013-11-01

    Sanitary landfill leachate is considered as highly polluted wastewater, without any treatment, discharging into water system will cause underground water and surface water pollutions. This study was to investigate the treatability of the semi-aerobic landfill leachate via coagulation-flocculation using poly-aluminum chloride (PAC), cationic polymer, and modified micro sand. Leachate was collected from Pulau Burung Sanitary Landfill (PBSL) located in Penang, Malaysia. Coagulation-flocculation was performed by using jar test equipment and the effect of pH, dose of coagulant and dose of polymer toward removal of chemical oxygen demand (COD), color and suspended solid (SS) were examined. Micro sand was also used in this study to compare settling time of coagulation-flocculation process. The optimum pH, dose of coagulant (PAC) and dose of polymer (cationic) achieved were 7.0, 1000 mg/L and 8 mg/L, respectively. The dose of micro sand used for the settling time process was 300 mg/L. Results showed that 52.66% removal of COD, 97.16% removal of SS and 96.44% removal of color were achieved under optimum condition. The settling times for the settling down of the sludge or particles that formed during coagulation-flocculation process were 1 min with modified sand, 20 min with raw micro sand and 45 min without micro sand.

  11. Autoantibodies to coagulation factors: from pathophysiology to diagnosis and therapy.

    PubMed

    Cugno, Massimo; Gualtierotti, Roberta; Tedeschi, Alberto; Meroni, Pier Luigi

    2014-01-01

    Autoantibodies may develop against coagulation factors altering their function or promoting their rapid clearance. In non-congenitally deficient patients, they are usually in association with autoimmune diseases, malignancies, pregnancy or advanced age. The possible development of coagulation factor autoantibodies should be considered when a patient presents with bleeding symptoms without any prior bleeding diathesis. The most common disorder associated with coagulation factor autoantibodies is acquired factor VIII deficiency, which is characterized by hemorrhages involving soft tissues, muscles and skin; hemarthroses are less frequent than in the inherited form. Acquired deficiencies of von Willebrand factor and factor XIII due to autoantibodies are emerging conditions. Autoantibodies to the other coagulation factors may be associated with a wide spectrum of clinical manifestations ranging from minimal or no bleeding to life-threatening conditions. The diagnostic approach begins with global coagulation tests: prothrombin time (PT) and activated partial thromboplastin time (aPTT). In case of prolonged times, mixing studies (typically using normal plasma in a 1:1 proportion) should be performed. Specific factor and inhibitor assays, assessment of lupus anticoagulant and eventually enzyme immunoassays for specific anti-factor antibodies complete the evaluation. A prompt diagnosis of specific coagulation factor inhibitors is mandatory for starting an appropriate treatment aimed at overcoming the deficient factor, in case of bleeding, and, if possible, at the suppression of the autoantibody's production. © 2013 Elsevier B.V. All rights reserved.

  12. Removal of dispersant-stabilized carbon nanotubes by regular coagulants.

    PubMed

    Liu, Ni; Liu, Changli; Zhang, Jing; Lin, Daohui

    2012-01-01

    Coagulation followed by sedimentation, as a conventional technique in the water treatment plant, can be the first line of defense against exposures of carbon nanotubes (CNTs) to aquatic organisms and human beings, which has been rarely documented. This study investigated the removal of dispersant-stabilized CNT suspensions by poly aluminum chloride (PACl) and KAl(SO4)2 x 12H2O (alum), with a focus on the effects of dispersant type, coagulant type and dosage. PACl performed better than alum in the removal of tannic acid-, humic acid-, and sodium dodecyl benzenesulfonate-stabilized CNTs, but worse for polyethylene glycol octylphenyl ether (TX100)-stabilized CNTs. Neither coagulant could effectively precipitate cetyltrimethyl ammonium bromide-stabilized CNTs. The removal by PACl first increased up to a plateau and then decreased with the continued increase of coagulant dosage. However, the removal rates leveled off but did not decrease after achieving their highest level with the continued addition of alum. The coagulation and flocculation of the CNT suspensions by PACl could be regulated mainly by the mechanism of adsorption charge neutralization, whereas the coagulation by alum mainly involved electrical double-layer compression.

  13. Coagulation-flocculation for lignin removal from wastewater - a review.

    PubMed

    Nawaz, Arfa; Ahmed, Zaki; Shahbaz, Ali; Khan, Zahra; Javed, Mohsin

    2014-01-01

    Industrial discharge has tremendously increased inorganic pollutants in water bodies all over the world. Paper and pulp effluent is included in one of the most pollution generating discharges containing complex chemical compounds such as lignin. For clean and healthy water resources, the recovery of lignin from wastewater from the paper and pulp industry is of high importance. Available chemical and biological technologies for removal of lignin have certain drawbacks. Coagulation and flocculation is not only the economic but also the effective method for removal of lignin. The present review highlights available coagulants employed for removal of lignin from paper and pulp wastewater. Each coagulant is pH dependent and shows varied results with change in effluent characteristics. The hydrolysis products of aluminium-based coagulants, iron-based coagulants and copper sulphate have positive charges. These positive charges promote formation of flocs through charged neutralisation or sweep flocculation. In the case of titanium-based coagulants, hydrolysis product is negatively charged and mode is heterocoagulation. Ninety percent recovery of lignin is achieved by using a mixture of oxotitanium sulphate and aluminium sulphate and 80% with aluminium sulphate. Virtually complete recovery of lignin is observed with oxotitanium sulphate.

  14. Does whole blood coagulation analysis reflect developmental haemostasis?

    PubMed

    Ravn, Hanne Berg; Andreasen, Jo Bnding; Hvas, Anne-Mette

    2016-07-27

    Developmental haemostasis has been well documented over the last 3 decades and age-dependent reference ranges have been reported for a number of plasmatic coagulation parameters. With the increasing use of whole blood point-of-care tests like rotational thromboelastometry (ROTEM) and platelet function tests, an evaluation of age-dependent changes is warranted for these tests as well. We obtained blood samples from 149 children, aged 1 day to 5.9 years, and analysed conventional plasmatic coagulation tests, including activated partial prothrombin time, prothrombin time, and fibrinogen (functional). Whole blood samples were analysed using ROTEM to assess overall coagulation capacity and Multiplate analyzer to evaluate platelet aggregation. Age-dependent changes were analysed for all variables. We found age-dependent differences in all conventional coagulation tests (all P values < 0.05), but there was no sign of developmental changes in whole blood coagulation assessment when applying ROTEM, apart from clotting time in the EXTEM assay (P < 0.03). Despite marked differences in mean platelet aggregation between age groups, data did not reach statistical significance. Citrate-anticoagulated blood showed significantly reduced platelet aggregation compared with blood anticoagulated with heparin or hirudin (all P values < 0.003). We confirmed previous developmental changes in conventional plasmatic coagulation test. However, these age-dependent changes were not displayed in whole blood monitoring using ROTEM or Multiplate analyzer. Type of anticoagulant had a significant influence on platelet aggregation across all age groups.

  15. Treatment of paper and pulp mill effluent by coagulation.

    PubMed

    Chaudhari, Parmesh Kumar; Majumdar, Bidyut; Choudhary, Rumi; Yadav, Deepak Kumar; Chand, Shri

    2010-04-01

    Pulp and paper mill effluent is highly polluting and is a subject of great environmental concern. In the present research we studied the removal of chemical oxygen demand (COD) and colour from paper mill effluent, using the coagulation process. A batch coagulation study was conducted using various coagulants such as aluminium chloride (AlCl3), polyaluminium chloride (PAC) and copper sulphate (CuSO4 x 5H20). The initial pH of the effluent had a tremendous effect on the COD and colour removal. The PAC reduced COD by 83% and reduced colour by 92% at an optimum pH of 5.0 and a coagulant dose of 8 mL L(-1). With AlCl3, at an optimum pH of 4.0 and a coagulant dose of 5 g L(-1), 72% COD removal and 84% colour removal were observed. At an optimum pH of 6.0 and a mass loading of 5 g L(-1), 76% COD reduction and 78% colour reduction were obtained with copper sulphate. It was also observed that, after addition of coagulant, the pH of the effluent decreased. The decrease in the pH was highest with AlCl3, followed by PAC and then CuSO4 x 5H20.

  16. Activation of blood coagulation in cancer: implications for tumour progression

    PubMed Central

    Lima, Luize G.; Monteiro, Robson Q.

    2013-01-01

    Several studies have suggested a role for blood coagulation proteins in tumour progression. Herein, we discuss (1) the activation of the blood clotting cascade in the tumour microenvironment and its impact on primary tumour growth; (2) the intravascular activation of blood coagulation and its impact on tumour metastasis and cancer-associated thrombosis; and (3) antitumour therapies that target blood-coagulation-associated proteins. Expression levels of the clotting initiator protein TF (tissue factor) have been correlated with tumour cell aggressiveness. Simultaneous TF expression and PS (phosphatidylserine) exposure by tumour cells promote the extravascular activation of blood coagulation. The generation of blood coagulation enzymes in the tumour microenvironment may trigger the activation of PARs (protease-activated receptors). In particular, PAR1 and PAR2 have been associated with many aspects of tumour biology. The procoagulant activity of circulating tumour cells favours metastasis, whereas the release of TF-bearing MVs (microvesicles) into the circulation has been correlated with cancer-associated thrombosis. Given the role of coagulation proteins in tumour progression, it has been proposed that they could be targets for the development of new antitumour therapies. PMID:23889169

  17. Activation of blood coagulation in cancer: implications for tumour progression.

    PubMed

    Lima, Luize G; Monteiro, Robson Q

    2013-09-04

    Several studies have suggested a role for blood coagulation proteins in tumour progression. Herein, we discuss (1) the activation of the blood clotting cascade in the tumour microenvironment and its impact on primary tumour growth; (2) the intravascular activation of blood coagulation and its impact on tumour metastasis and cancer-associated thrombosis; and (3) antitumour therapies that target blood-coagulation-associated proteins. Expression levels of the clotting initiator protein TF (tissue factor) have been correlated with tumour cell aggressiveness. Simultaneous TF expression and PS (phosphatidylserine) exposure by tumour cells promote the extravascular activation of blood coagulation. The generation of blood coagulation enzymes in the tumour microenvironment may trigger the activation of PARs (protease-activated receptors). In particular, PAR1 and PAR2 have been associated with many aspects of tumour biology. The procoagulant activity of circulating tumour cells favours metastasis, whereas the release of TF-bearing MVs (microvesicles) into the circulation has been correlated with cancer-associated thrombosis. Given the role of coagulation proteins in tumour progression, it has been proposed that they could be targets for the development of new antitumour therapies.

  18. Moojenactivase, a novel pro-coagulant PIIId metalloprotease isolated from Bothrops moojeni snake venom, activates coagulation factors II and X and induces tissue factor up-regulation in leukocytes.

    PubMed

    Sartim, Marco A; Costa, Tassia R; Laure, Helen J; Espíndola, Milena S; Frantz, Fabiani G; Sorgi, Carlos A; Cintra, Adélia C O; Arantes, Eliane C; Faccioli, Lucia H; Rosa, José C; Sampaio, Suely V

    2016-05-01

    Coagulopathies following snakebite are triggered by pro-coagulant venom toxins, in which metalloproteases play a major role in envenomation-induced coagulation disorders by acting on coagulation cascade, platelet function and fibrinolysis. Considering this relevance, here we describe the isolation and biochemical characterization of moojenactivase (MooA), a metalloprotease from Bothrops moojeni snake venom, and investigate its involvement in hemostasis in vitro. MooA is a glycoprotein of 85,746.22 Da, member of the PIIId group of snake venom metalloproteases, composed of three linked disulfide-bonded chains: an N-glycosylated heavy chain, and two light chains. The venom protease induced human plasma clotting in vitro by activating on both blood coagulation factors II (prothrombin) and X, which in turn generated α-thrombin and factor Xa, respectively. Additionally, MooA induced expression of tissue factor (TF) on the membrane surface of peripheral blood mononuclear cells (PBMC), which led these cells to adopt pro-coagulant characteristics. MooA was also shown to be involved with production of the inflammatory mediators TNF-α, IL-8 and MCP-1, suggesting an association between MooA pro-inflammatory stimulation of PBMC and TF up-regulation. We also observed aggregation of washed platelets when in presence of MooA; however, the protease had no effect on fibrinolysis. Our findings show that MooA is a novel hemostatically active metalloprotease, which may lead to the development of coagulopathies during B. moojeni envenomation. Moreover, the metalloprotease may contribute to the development of new diagnostic tools and pharmacological approaches applied to hemostatic disorders.

  19. Evaluation of the coagulation profile among oral and vaginal combined hormonal contraceptive users using sonoclot coagulation analyzer.

    PubMed

    Brandy, Kyle R; Meyer, Rachel M; Luo, Xianghua; Rao, Gundu H; Datta, Yvonne H; Divani, Afshin A

    2012-11-01

    Combined hormonal contraceptives possess an inherent risk of thrombus-related events. The purpose of this study is to elucidate alterations in the coagulation profile among young women using combined oral contraceptive (COC) or combined vaginal contraceptive (CVC) compared to a normal, healthy, female control group using the Sonoclot coagulation analyzer. We enrolled 159 participants (64 control individuals, 51 COC users, and 44 CVC users). Each participant completed a survey of medical history, family medical history, and lifestyle choices. Citrated venous whole blood was collected and analyzed using the Sonoclot coagulation analyzer. After adjusting for age, race, alcohol consumption, sleeping habits, and family history of cardiovascular disease, and stroke, we observed COC and CVC users had mostly similar coagulation profiles except when compared to the control, and COC and CVC users had an elevated glass bead peak signal while COC users had a shorter peak time.

  20. Particles in Surface Waters: Coagulation and Transport.

    NASA Astrophysics Data System (ADS)

    Culkin, Gerald William

    Conventional water quality assessment and simulation of particles in natural waters focus on bulk concentrations of the suspended solid phase. These analyses rely directly or indirectly on a linear, 'average particle' approach to describe processes that are nonlinear and highly size -dependent. Size-dependent transport and transformation mechanisms were simulated in this research to identify conditions in which coagulation is important. Explicit finite difference schemes for two-dimensional, laterally-averaged, unsteady particle transport were developed to approximate the size -dependent particle transport processes, which included advection, dispersion, and settling. Coupled exchange of discrete particles between the water column and sediment bed was modeled using size-dependent particle sedimentation and resuspension. Simultaneous particle-particle flocculation was integrated over time in parallel with transport. Model simulations of systems with idealized morphometry and forcing provided greater insight to competing processes that drive particle behavior in natural systems. Application of the model to a real system gave plausible results and suggested explanations for observed conditions.

  1. Planetesimal formation by sweep-up coagulation

    NASA Astrophysics Data System (ADS)

    Windmark, Fredrik; Birnstiel, Til; Ormel, Chris W.; Dullemond, Cornelis P.

    2013-07-01

    The formation of planetesimals is often accredited to collisional sticking of dust grains in the protoplanetary disk. The exact process is however unknown, as collisions between larger aggregates tend to lead to fragmentation or bouncing rather than sticking. These growth barriers tend to halt the dust growth already at millimeters or centimeters in size, which is far below the kilometer-sizes that are needed for gravity to aid in the accretion. To study how far dust coagulation can proceed, we have developed a new collision model based on the latest laboratory experiments, and have used it together with a dust-size evolution code capable of resolving all grain interactions in the protoplanetary disk. We find that for the general dust population, bouncing and fragmenting collisions prevent the growth above millimeter-sizes. However, a small number of lucky particles can grow larger than the rest by only interacting at low, sticky velocities. As they grow, they become increasingly resilient to fragmentation caused by the small grains. In this way, two populations are formed: One which remains small due to the collisional barriers, and one that continues to grow by sweeping up the smaller grains around them.

  2. Oxidation inhibits iron-induced blood coagulation.

    PubMed

    Pretorius, Etheresia; Bester, Janette; Vermeulen, Natasha; Lipinski, Boguslaw

    2013-01-01

    Blood coagulation under physiological conditions is activated by thrombin, which converts soluble plasma fibrinogen (FBG) into an insoluble clot. The structure of the enzymatically-generated clot is very characteristic being composed of thick fibrin fibers susceptible to the fibrinolytic degradation. However, in chronic degenerative diseases, such as atherosclerosis, diabetes mellitus, cancer, and neurological disorders, fibrin clots are very different forming dense matted deposits (DMD) that are not effectively removed and thus create a condition known as thrombosis. We have recently shown that trivalent iron (ferric ions) generates hydroxyl radicals, which subsequently convert FBG into abnormal fibrin clots in the form of DMDs. A characteristic feature of DMDs is their remarkable and permanent resistance to the enzymatic degradation. Therefore, in order to prevent thrombotic incidences in the degenerative diseases it is essential to inhibit the iron-induced generation of hydroxyl radicals. This can be achieved by the pretreatment with a direct free radical scavenger (e.g. salicylate), and as shown in this paper by the treatment with oxidizing agents such as hydrogen peroxide, methylene blue, and sodium selenite. Although the actual mechanism of this phenomenon is not yet known, it is possible that hydroxyl radicals are neutralized by their conversion to the molecular oxygen and water, thus inhibiting the formation of dense matted fibrin deposits in human blood.

  3. [Shock and coagulation disorders in systemic mastocytosis].

    PubMed

    Hansen, U; Wiese, R; Knolle, J

    1994-09-16

    A 41-year-old man was admitted in circulatory shock of unknown aetiology (systolic pressure 50 mm Hg) and marked reddening of the upper part of the body as well as maculopapular rash over the whole body. After 1500 ml of colloidal solution had been infused the blood pressure rose to a level at which the patient's condition was no longer at risk. He reported having had a similar attack of flushing and circulatory collapse during the last few years, each time after drinking 3-41 of beer. Laboratory tests showed thromboplastin time 56%, partial thromboplastin time 130 s and thrombin time > 180 s. Three hours after admission the coagulation times had further deteriorated, but had become normal within 20 hours. After rest and after a provocation (hot bath) the serum concentrations were: heparin 0.21 U/ml and 0.85 U/ml; histamine 1.9 micrograms/ml and 2.3 micrograms/ml; serotonin 23 micrograms/ml and 38 micrograms/ml. Histological examination of an iliac crest bone marrow biopsy revealed dense collections of mast cells, as seen in systemic mastocytosis. A skin biopsy was diagnostic of urticaria pigmentosa.

  4. Coagulation Profiling of Random-Source Cats

    PubMed Central

    McGeehan, Elizabeth; Wielgus, Karen; Cera, Lee; Azarafrooz, Farshid; Buesing, Rose; Dubach, Jean; Fareed, Jawed

    2010-01-01

    The chemistry and hemostatic parameters of class B vendor cats (Felis catus) can show wide levels of variation, possibly because of initial health status. We compared prothrombin time, partial thromboplastin time, common pathway assay and thrombin time between Class B vendor cats (n = 30) and a control group of healthy cats (n = 16). The antiprotease activities of antiXa, antiIIa, heparin cofactor II, and antithrombin were measured also. Plasma samples from citrated blood were analyzed by using standard clotting assays and commercially available chromogenic substrate assays. Tests for homogeneity of variances and 1-way ANOVA were used to test for significant differences between groups. Results of ANOVA were highly significant between groups for heparin cofactor II and Heptest activity levels. Variances were significantly different between groups for prothrombin time; therefore, an ANOVA was not done. These studies suggest that the class B cats exhibited sufficiently wide variations in their coagulation parameters that they may not be optimal subjects for vascular or cardiovascular research. PMID:20122312

  5. Inflammation and coagulation in urticaria and angioedema.

    PubMed

    Cugno, Massimo; Asero, Riccardo; Tedeschi, Alberto; Lazzari, Riccardo; Marzano, Angelo V

    2012-09-01

    Urticaria is a skin disease characterised by short-lived surface swellings of the dermis (wheals) frequently accompanied by itching. It is classified as acute or chronic depending on whether the wheal recurrence occurs for less or more than six weeks. Acute urticaria is often due to a hypersensitivity reaction, whereas about 50% of the cases of chronic urticaria are regarded as autoimmune. Urticaria may occur alone or in association with a deeper swelling (angioedema) involving the subcutaneous and/or submucosal tissues, and last from hours to a few days. Angioedema can also develop alone, and may be idiopathic or be caused by allergies, inherited or acquired deficiencies of C1-inhibitor protein, or adverse drug reactions. An interplay between inflammation and coagulation has been proposed as a pathomechanism in urticaria and urticaria-associated angioedema (in which histamine and thrombin are involved), as well as in angioedema due to C1-inhibitor deficiency, which involves various biological systems. An increase in the plasma markers of thrombin generation, fibrinolysis and inflammation has been documented during exacerbations of urticaria and angioedema, with the marker levels decreasing to normal during remission. However, the hypercoagulable state in chronic urticaria and angioedema has not been reported to be associated with any increased risk of thrombosis, although there have been a number of reports of cardiovascular events occurring during episodes of acute urticaria. These observations have provided the rationale for the clinical evaluation of anticoagulant and antifibrinolytic drugs, the efficacy of which has sometimes been demonstrated.

  6. Blood coagulation reactions on nanoscale membrane surfaces

    NASA Astrophysics Data System (ADS)

    Pureza, Vincent S.

    Blood coagulation requires the assembly of several membrane-bound protein complexes composed of regulatory and catalytic subunits. The biomembranes involved in these reactions not only provide a platform for these procoagulant proteins, but can also affect their function. Increased exposure of acidic phospholipids on the outer leaflet of the plasma membrane can dramatically modulate the catalytic efficiencies of such membrane-bound enzymes. Under physiologic conditions, however, these phospholipids spontaneously cluster into a patchwork of membrane microdomains upon which membrane binding proteins may preferentially assemble. As a result, the membrane composition surrounding these proteins is largely unknown. Through the development and use of a nanometer-scale bilayer system that provides rigorous control of the phospholipid membrane environment, I investigated the role of phosphatidylserine, an acidic phospholipid, in the direct vicinity (within nanometers) of two critical membrane-bound procoagulant protein complexes and their respective natural substrates. Here, I present how the assembly and function of the tissue factor˙factor VIIa and factor Va˙factor Xa complexes, the first and final cofactor˙enzyme complexes of the blood clotting cascade, respectively, are mediated by changes in their immediate phospholipid environments.

  7. High power visible diode laser for the treatment of eye diseases by laser coagulation

    NASA Astrophysics Data System (ADS)

    Heinrich, Arne; Hagen, Clemens; Harlander, Maximilian; Nussbaumer, Bernhard

    2015-03-01

    We present a high power visible diode laser enabling a low-cost treatment of eye diseases by laser coagulation, including the two leading causes of blindness worldwide (diabetic retinopathy, age-related macular degeneration) as well as retinopathy of prematurely born children, intraocular tumors and retinal detachment. Laser coagulation requires the exposure of the eye to visible laser light and relies on the high absorption of the retina. The need for treatment is constantly increasing, due to the demographic trend, the increasing average life expectancy and medical care demand in developing countries. The World Health Organization reacts to this demand with global programs like the VISION 2020 "The right to sight" and the following Universal Eye Health within their Global Action Plan (2014-2019). One major point is to motivate companies and research institutes to make eye treatment cheaper and easily accessible. Therefore it becomes capital providing the ophthalmology market with cost competitive, simple and reliable technologies. Our laser is based on the direct second harmonic generation of the light emitted from a tapered laser diode and has already shown reliable optical performance. All components are produced in wafer scale processes and the resulting strong economy of scale results in a price competitive laser. In a broader perspective the technology behind our laser has a huge potential in non-medical applications like welding, cutting, marking and finally laser-illuminated projection.

  8. Coagulation of humic waters for diffused pollution control and the influence of coagulant type on DOC fractions removed.

    PubMed

    Heiderscheidt, Elisangela; Leiviskä, Tiina; Kløve, Bjørn

    2016-10-01

    This study examined the suitability of organic coagulants for treatment of typically humic peat extraction runoff water by comparing their performance with that of ferric sulphate (FS). The influence of coagulant type on dissolved organic carbon (DOC) fractions removed was analysed in detail using LC-OCD-OND (size exclusion liquid chromatography coupled with organic carbon and organic nitrogen detection) fractionation techniques. In general, lower coagulant dosage was needed under acidic (pH 4.5) than neutral (pH 6.5) conditions. Chitosan (Chit) and poly (diallyldimethyl) ammonium chloride (pDMAC) required significantly lower dosage (40-55%) than FS for acceptable purification, while a tannin-based coagulant (Tan2) required substantially higher dosage (55-75%) independent of water pH. FS demonstrated the best removal of DOC (<81%) and phosphorus (<93%) followed by pDMAC, while Chit and Tan2 achieved the highest removal of suspended solids (SS) (<58%), with flocs formed by Tan2 presenting the best settling properties. Higher molecular weight (MW) DOC fractions were more efficiently removed by all coagulants, with FS being the most efficient (biopolymers 69% and humic substances 91%), followed by Tan2. FS also displayed satisfactory removal of lower MW fractions (building blocks ∼46% and low MW neutrals 62%). Overall, FS was the best performing coagulant. Nevertheless, the organic polymers demonstrated satisfactory overall performance, achieving purification rates mostly inside the requirements set by Finnish environmental authorities.

  9. Optimisation of combined coagulation and microfiltration for water treatment.

    PubMed

    Judd, S J; Hillis, P

    2001-08-01

    The effect of upstream coagulant dosing for full-flow microfiltration of an upland-reservoir water has been investigated. The process, run under conditions of constant flux and pH and based on a ferric salt, is compared with a published study of another full-flow process based on alum dosing and operated at constant pressure and coagulant concentration. The current study includes data for the residual deposit remaining following backflushing by reverse flow. Results are presented in terms of the specific-cake resistance (R'o, m(-2)) as a function of pH or coagulant dose. Reasonable correlation with classical cake filtration theory was obtained, such that R' was assumed to be independent of run time and cake thickness. The following trends have been noted: The optimum pH for the alum-based system appears to be between 7.5 and 8 on the basis of cake resistance. The effect of coagulant dose between 18 and 71 microM Fe3+ is much more significant than a change in pH between 5 and 9 for the alum system: a 53-fold increase in specific flux compared with a 7-fold increase with reference to the limiting R'o values at pH 4.8 and 7.7. A low coagulant dose (0.018mM, 1.0 mg l(-1) Fe3+) appears to have a slightly detrimental effect on downstream microfiltration operation. The low coagulant doses apparently cause incomplete aggregation of colloidal particles such that internal fouling of the membrane takes place. The residual (cleaning cycle) deposit resistance followed roughly the same trend as the backflush cycle-cake resistance with coagulant concentration, but with a much reduced value (about 16 times lower, on average). An optimum coagulant dose of 0.055 mM (3.1 mg/l) Fe3+ can be identified on the basis of operational cost based on coagulant cost and cake resistance, all other aspects of the system being substantially unchanged. It is concluded that coagulation with downstream microfiltration offers a cost-effective means of removing natural organic matter, achieving a THMFP

  10. Characterization and coagulation of a polyaluminum chloride (PAC) coagulant with high Al13 content.

    PubMed

    Gao, Bao-Yu; Chu, Yong-Bao; Yue, Qin-Yan; Wang, Bing-Jian; Wang, Shu-Guang

    2005-07-01

    A polyaluminum chloride (PAC) coagulant was prepared from AlCl3 x 6H2O and Na2CO3. The Al13 species in PAC was separated and purified by the SO4(2-)/Ba2+ deposition-replacement method, and characterized by 27Al-NMR and XRD. From 27Al-NMR spectroscopy, it was found that PAC obtained after separation and purification contained more Al13 (PAC-Al13, for short) than original PAC before separation and purification. In XRD spectra, a strong Al13 signal appeared in the range of 2theta from 5 to 25 degrees. Jar tests were performed to test the coagulation efficiency of AlCl3, PAC and PAC-Al13 in treating synthetic or actual water samples. Compared with PAC and AlCl3, PAC-Al13 gives the best results for turbidity, humic acid and color removal, and achieves the highest charge-neutralizing ability. Under the study conditions, PAC-Al13 gave about 90% humic acid removal and almost 100% reactive blue dye removal when its dosages were 4.0 and 15 mg/L as Al, respectively. The Al13 species has a higher positive charge and is the most effective polymeric Al species in water and wastewater treatment.

  11. [Comparison of thromboelastography and routine coagulation tests for evaluation of blood coagulation function in patients].

    PubMed

    Chen, Guan-Yi; Ou Yang, Xi-Lin; Wu, Jing-Hui; Wang, Li-Hua; Yang, Jin-Hua; Gu, Li-Nan; Lu, Zhu-Jie; Zhao, Xiao-Zi

    2015-04-01

    To investigate the correlation and consistency between thromboelastography(TEG) and routine coagulation tests, and to evaluate the value of the two methods in determining the blood coagulation of patients. The TEG, routine coagulation tests and platelet counts of 182 patients from the Intensive Care Unit(ICU) and Department of Gastroenterology in our hospital from January to September 2014 were performed and analyzed retrospectively for their correlation, Kappa identity test analysis and chi-square test, and the diagnostic sensitivity and specificity of both methods in the patients with bleeding were evaluated. The TEG R time and PT, R time and APTT showed a linear dependence (P<0.01). The relationship between the TEG K value, α-Angle, MA and Fibrinogen showed a linear dependence (P<0.001). And the relationship between the TEG K value, α-Angle, MA and the platelet count were in a linear dependent way (P<0.001). The Kappa values of the TEG R time with PT and APTT were 0.038 (P>0.05) and 0.061 (P>0.05), respectively. The chi-square test values of the TEG R time with PT and APTT were 35.309 (P<0.001) and 15.848 (P<0.001), respectively. The Fibrinogen and the TEG K value, α-Angle, MA value had statistical significance (P<0.001), with a Kappa value of 0.323, 0.288 and 0.427, respectively. The chi-square test values between Fibrinogen and the TEG K value, α-Angle, MA value were not statistically significant, with X2=1.091 (P=0.296), X2=1.361 (P=0.243), X2=0.108 (P=0.742). The Kappa values of the platelet count and the TEG K value, α-Angle, MA value were 0.379, 0.208 and 0.352, respectively, which were also statistically significant difference (P<0.001). The chi-square test values between the platelet count and the TEG K value, α-Angle, MA value showed a statistically significant difference (P<0.001), with X2=37.5, X2=37.23, X2=26.630. The diagnostic sensitivity of the two methods for the patients with bleeding was less than 50%. There was a significant correlation

  12. Intraoperative Changes in Blood Coagulation and Thrombelastographic Monitoring in Liver Transplantation

    PubMed Central

    Kang, Yoo Goo; Martin, Douglas J.; Marquez, Jose; Lewis, Jessica H.; Bontempo, Franklin A.; Shaw, Byers W.; Starzl, Thomas E.; Winter, Peter M.

    2010-01-01

    The blood coagulation system of 66 consecutive patients undergoing consecutive liver transplantations was monitored by thrombelastograph and analytic coagulation profile. A poor preoperative coagulation state, decrease in levels of coagulation factors, progressive fibrinolysis, and whole blood clot lysis were observed during the preanhepatic and anhepatic stages of surgery. A further general decrease in coagulation factors and platelets, activation of fibrinolysis, and abrupt decrease in levels of factors V and VIII occurred before and with reperfusion of the homograft. Recovery of blood coagulability began 30–60 min after reperfusion of the graft liver, and coagulability had returned toward baseline values 2 hr after reperfusion. A positive correlation was shown between the variables of thrombelastography and those of the coagulation profile. Thrombelastography was shown to be a reliable and rapid monitoring system. Its use was associated with a 33% reduction of blood and fluid infusion volume, whereas blood coagulability was maintained without an increase in the number of blood product donors. PMID:3896028

  13. Coagulation and fibrinolysis in injured patients

    PubMed Central

    Innes, D.; Sevitt, S.

    1964-01-01

    Serial changes in coagulation and fibrinolysis studied among 42 patients admitted to hospital with a wide variety of injuries are reported. The first hours after trauma are dominated by an acceleration of fibrinolysis (clot lysis) and clotting time which are often followed by an abrupt rebound to prolonged fibrinolysis and normal clotting. Evidence is presented that acceleration of fibrinolysis is due to flooding of the circulation by plasminogen activator and that prolongation is probably due to an inhibitor. A prolonged prothrombin time, increased prothrombin consumption index, an acceleration of the heparin-retarded clotting time, and a fall in the platelet count are also frequent during the first hours after injury. There is evidence also of an early deficiency in factor V and the onset of a fall in factor VII and prothrombin. The following days are characterized by continued prolongation of fibrinolysis, a lengthening of clotting time, and an increased prothrombin consumption index suggestive of a defect in thrombo-plastin generation. Subsequent periods of prolonged fibrinolysis may develop. Prothrombin time often continues prolonged for one to three weeks and may vary phasically; plasma prothrombin and factor VII are reduced but there is now little change in factor V. The platelet count continues to fall for one to three days, then a thrombocytosis develops, often with abnormally high platelet levels, a week or so later. Plasma fibrinogen rises within 24 hours to reach a plateau maximum a few days later and levels remain high for prolonged periods in the severely injured. Various changes are related to or influenced by the severity of trauma. Mechanisms are discussed, including thrombosis in vivo, and reference is made to homeostatic significance and its possible breakdown. PMID:14103515

  14. Instantaneous gelation in Smoluchowski's coagulation equation revisited

    NASA Astrophysics Data System (ADS)

    Ball, Robin C.; Connaughton, Colm; Stein, Thorwald H. M.; Zaboronski, Oleg

    2011-07-01

    We study the solutions of the Smoluchowski coagulation equation with a regularization term which removes clusters from the system when their mass exceeds a specified cutoff size, M. We focus primarily on collision kernels which would exhibit an instantaneous gelation transition in the absence of any regularization. Numerical simulations demonstrate that for such kernels with monodisperse initial data, the regularized gelation time decreases as M increases, consistent with the expectation that the gelation time is zero in the unregularized system. This decrease appears to be a logarithmically slow function of M, indicating that instantaneously gelling kernels may still be justifiable as physical models despite the fact that they are highly singular in the absence of a cutoff. We also study the case when a source of monomers is introduced in the regularized system. In this case a stationary state is reached. We present a complete analytic description of this regularized stationary state for the model kernel, K(m1,m2)=max{m1,m2}ν, which gels instantaneously when M→∞ if ν>1. The stationary cluster size distribution decays as a stretched exponential for small cluster sizes and crosses over to a power law decay with exponent ν for large cluster sizes. The total particle density in the stationary state slowly vanishes as [(ν-1)logM]-1/2 when M→∞. The approach to the stationary state is nontrivial: Oscillations about the stationary state emerge from the interplay between the monomer injection and the cutoff, M, which decay very slowly when M is large. A quantitative analysis of these oscillations is provided for the addition model which describes the situation in which clusters can only grow by absorbing monomers.

  15. Dysfunction in the coagulation system and schizophrenia

    PubMed Central

    Hoirisch-Clapauch, S; Amaral, O B; Mezzasalma, M A U; Panizzutti, R; Nardi, A E

    2016-01-01

    Although different hypotheses have been formulated to explain schizophrenia pathogenesis, the links between them are weak. The observation that five psychotic patients on chronic warfarin therapy for deep-vein thrombosis showed long-term remission of psychotic symptoms made us suspect that abnormalities in the coagulation pathway, specifically low tissue plasminogen activator (tPA) activity, could be one of the missing links. Our hypothesis is supported by a high prevalence of conditions affecting tPA activity in drug-naive schizophrenia, such as antiphospholipid antibodies, elevated cytokine levels, hyperinsulinemia and hyperhomocysteinemia. We recently screened a group of schizophrenia patients and controls for conditions affecting tPA activity. Free-protein S deficiency was highly prevalent among patients, but not found in controls. Free-protein S and functional protein C are natural anticoagulants that form complexes that inhibit tPA inhibitors. All participants had normal protein C levels, suggesting that protein S could have a role in schizophrenia, independent of protein C. Chronic patients and those studied during acute episodes had between three and six conditions affecting tPA and/or protein S activity, while patients in remission had up to two, which led us to postulate that multiple conditions affecting tPA and/or protein S activity could contribute to the full expression of schizophrenia phenotype. This paper describes the physiological roles of tPA and protein S, reviewing how their activity influences pathogenesis and comorbidity of schizophrenia. Next, it analyzes how activity of tPA and protein S is influenced by biochemical abnormalities found in schizophrenia. Last, it suggests future directions for research, such as studies on animal models and on therapeutic approaches for schizophrenia aiming at increasing tPA and protein S activity. PMID:26731441

  16. Coagulation monitoring based on blood elastic measurement using optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Xu, Xiangqun; Zhu, Jiang; Chen, Zhongping

    2017-02-01

    Blood coagulation monitoring is important to diagnose hematological diseases and cardiovascular diseases and to predict the risk of bleeding and excessive clotting. In this study, we developed a system to dynamically monitor blood coagulation and quantitatively determine the coagulation function by blood elastic measurement. When blood forms a clot from a liquid, ultrasonic force induces a shear wave, which is detected by optical coherence tomography (OCT). The coagulation of porcine whole blood recalcified by calcium chloride is assessed using the metrics of reaction time, clot formation kinetics and maximum shear modulus. The OCE system can noninvasively monitor the blood coagulation and quantitatively determine the coagulation function.

  17. Comparison of Moringa stenopetala seed extract as a clean coagulant with Alum and Moringa stenopetala-Alum hybrid coagulant to remove direct dye from Textile Wastewater.

    PubMed

    Dalvand, Arash; Gholibegloo, Elham; Ganjali, Mohammad Reza; Golchinpoor, Najmeh; Khazaei, Mohammad; Kamani, Hossein; Hosseini, Sara Sadat; Mahvi, Amir Hossein

    2016-08-01

    In this study, the efficiency of Moringa stenopetala seed extract was compared with alum and M. stenopetala-alum hybrid coagulant to remove Direct Red 23 azo dye from textile wastewater. The effects of parameters such as pH, coagulant dose, type of salt used for the extraction of coagulant and initial dye concentration on dye removal efficiency were investigated. Moreover, the existing functional groups on the structure of M. stenopetala coagulant (MSC) were determined by Fourier transform infrared spectroscopy, and the morphology of sludge produced by MSC, alum, and hybrid coagulant was characterized by scanning electron microscopy. Ninhydrin test was also used to determine the quantity of primary amines in the MSC and Moringa oleifera coagulant (MOC). According to the results, with increasing the coagulant dose and decreasing the initial dye concentration, dye removal efficiency has increased. The maximum dye removal of 98.5, 98.2, and 98.3 % were obtained by using 240, 120, and 80 mg/L MSC, alum and hybrid coagulant at pH 7, respectively. The results also showed MSC was much more effective than MOC for dye removal. The volume of sludge produced by MSC was one fourth and half of those produced by alum and hybrid coagulant, respectively. Based on the results, hybrid coagulant was the most efficient coagulant for direct dye removal from colored wastewater.

  18. The effects of NOM and coagulation on copper corrosion

    SciTech Connect

    Rehring, J.P.; Edwards, M.

    1994-12-31

    Copper corrosion was examined in solutions containing natural organic matter (NOM) and in situations where NOM was removed by enhanced coagulation with alum or ferric chloride. Electrochemical methods were used to evaluate the long-term effects of each water quality on copper corrosion. In experiments exploring the role of NOM in copper corrosion, corrosion rates increased with NOM concentration at pH 6, whereas at pH 7.5 and 9 the NOM had less significant effects. Waters treated by enhanced alum coagulation had higher corrosion rates than untreated waters, but enhanced ferric chloride coagulation had the opposite effect. This difference was attributed to the relative effects of added sulfate via alum coagulation versus added chloride via ferric chloride coagulation. Compliance with the EPA Lead and Copper Rule and disinfection byproduct regulations may require that utilities address both regulations simultaneously. That is, water treatment processes, NOM concentration, and copper corrosion behavior are clearly interdependent and should be considered when contemplating changes to meet DBP regulations.

  19. Coagulation reaction in a one-dimensional gas

    SciTech Connect

    Sheu, W.; Van den Broeck, C.; Lindenberg, K. Institute for Nonlinear Science, University of California, San Diego, La Jolla, California 92093-0340 )

    1991-04-15

    An extension of previous work on the ballistic annihilation reaction {ital A}+{ital A}{r arrow}0 to the coagulation reaction {ital A}+{ital A}{r arrow}{ital A} is presented. Three possible velocities {ital c} (with probability {ital p}), {minus}{ital c} (with probability {ital q}), and zero are considered. While the long-time behavior is controlled by moving particles when {ital p}={ital q}, it is controlled by the stationary particles when {ital p}{ne}{ital q}. The comparison of the coagulation reaction with the annihilation reaction shows that the long-time results are essentially the same except for a rescaling of the time. In addition, the time dependences of the decay in the ballistic coagulation reaction when {ital p}={ital q} and the diffusion-limited coagulation reaction are also identical, but for different physical reasons. The reason for this becomes transparent by rederiving the ballistic coagulation results using a random-walk formalism, which can perhaps be generalized to more complicated ballistic reactions.

  20. Clay-catalyzed reactions of coagulant polymers during water chlorination

    USGS Publications Warehouse

    Lee, J.-F.; Liao, P.-M.; Lee, C.-K.; Chao, H.-P.; Peng, C.-L.; Chiou, C.T.

    2004-01-01

    The influence of suspended clay/solid particles on organic-coagulant reactions during water chlorination was investigated by analyses of total product formation potential (TPFP) and disinfection by-product (DBP) distribution as a function of exchanged clay cation, coagulant organic polymer, and reaction time. Montmorillonite clays appeared to act as a catalytic center where the reaction between adsorbed polymer and disinfectant (chlorine) was mediated closely by the exchanged clay cation. The transition-metal cations in clays catalyzed more effectively than other cations the reactions between a coagulant polymer and chlorine, forming a large number of volatile DBPs. The relative catalytic effects of clays/solids followed the order Ti-Mont > Fe-Mont > Cu-Mont > Mn-Mont > Ca-Mont > Na-Mont > quartz > talc. The effects of coagulant polymers on TPFP follow the order nonionic polymer > anionic polymer > cationic polymer. The catalytic role of the clay cation was further confirmed by the observed inhibition in DBP formation when strong chelating agents (o-phenanthroline and ethylenediamine) were added to the clay suspension. Moreover, in the presence of clays, total DBPs increased appreciably when either the reaction time or the amount of the added clay or coagulant polymer increased. For volatile DBPs, the formation of halogenated methanes was usually time-dependent, with chloroform and dichloromethane showing the greatest dependence. ?? 2003 Elsevier Inc. All rights reserved.

  1. Research on soybean curd coagulated by lactic acid bacteria.

    PubMed

    Jianming, Wang; Qiuqian, Lin; Yiyun, Wang; Xi, Chen

    2013-12-01

    Chinese traditional soybean curd is coagulated by calcium salt. In order to investigate the feasibility of soybean curd coagulation by lactic acid bacteria, we studied the effective factors in soybean curd coagulation when using common soybean curd strains. In soybean curd concentration, incubating time and temperature as well as the inoculated amount and the edible gum additives were studied as the coagulating factors of soybean curd fermented by lactic acid bacteria. Based on the single factor and orthogonal experiment design, the optimized conditions of lactic acid bacteria fermentation curd was determined as follows: soybean curd concentration 12.5%(v/v)and the fermentation conducted at 42°C for 5 hours when the inoculating amount was 4.0% and edible gum additives was 1.4% (carrageenan 1.0% (m/v), soluble starch 0.4% (m/v)). Under the optimum conditions, the water-holding rate of the bean curd was measured as 69.82%, and the gel strength was 25.6 g/cm(2). Compared with the traditional tofu coagulated by calcium salt, our products has less off-flavor and softer texture, which was accepted as new type of soybean curd according to the overall sensory evaluation.

  2. A mini review of preoxidation to improve coagulation.

    PubMed

    Xie, Pengchao; Chen, Yiqun; Ma, Jun; Zhang, Xiang; Zou, Jing; Wang, Zongping

    2016-07-01

    Preoxidation has attracted people's attention due to its effectiveness in enhancing coagulation. The mechanisms, drawbacks and applications in the improvement of coagulation were summarized in this work. Preoxidation can destroy the organic coating on the surface of particles to change the zeta potential, which is the vital reason for improving coagulation. Co-existing metallic ions, such as calcium, iron and manganese, play important roles in the improvement of coagulation due to the formation of metal-humate complexes or the in situ formed coagulant. However, preoxidation could degrade organic matter from high molecular weight to low molecular weight and damage cell membrane of algae, causing intracellular algal organic matter to release outside and producing hydrophilic functional groups to some extent, which has the potential to deteriorate the water quality. Additionally, disinfection byproduct formation is also affected significantly through changing the characteristics of the organic and inorganic precursors. Based on the recent publications, some future developments of preoxidation process were suggested in this study.

  3. Blood coagulation and propagation of autowaves in flow.

    PubMed

    Ermakova, Elena A; Panteleev, Mikhail A; Shnol, Emmanuil E

    2005-01-01

    This study analyses the effect of flow and boundary reactions on spatial propagation of waves of blood coagulation. A simple model of coagulation in plasma consisting of three differential reaction-diffusion equations was used for numerical simulations. The vessel was simulated as a two-dimensional channel of constant width, and the anticoagulant influence of thrombomodulin present on the undamaged vessel wall was taken into account. The results of the simulations showed that this inhibition could stop the coagulation process in the absence of flow in narrow channels. For the used mathematical model of coagulation this was the case if the width was below 0.2 mm. In wider vessels, the process could be stopped by the rapid blood flow. The required flow rate increased with the increase of the damage region size. For example, in a 0.5-mm wide channel with 1-mm long damage region, the propagation of coagulation may be terminated at the flow rate of more than 20 mm/min.

  4. Coagulation defects resulting from ambient temperature-induced hypothermia.

    PubMed

    Staab, D B; Sorensen, V J; Fath, J J; Raman, S B; Horst, H M; Obeid, F N

    1994-05-01

    Ambient temperature-induced hypothermia noted in trauma patients is frequently accompanied by a bleeding diathesis despite "laboratory normal" coagulation values. To document this impression, the following experiment was conducted. Coagulation studies and platelet function studies were performed in ten minipigs during induced whole body hypothermia (40 degrees C to 34 degrees C) and rewarming. Cooling was achieved in 2 to 3 hours and rewarming took 4 to 5 hours. In addition, similar coagulation and platelet function studies were conducted on plasma samples from the same animals that were cooled and then rewarmed in a water bath. Platelet counts and function as measured by Sonoclot analysis and aggregation did not decrease significantly with hypothermia in either model. Plasma cooled in a water bath demonstrated abnormal PT and aPTT (p < 0.001). Whole body hypothermia demonstrated abnormal bleeding time and PT (p < 0.001). Ambient temperature-induced hypothermia produced significant coagulation defects in a porcine model. Some of the coagulation defects were most pronounced during rewarming.

  5. Removal of perfluorooctanoate from surface water by polyaluminium chloride coagulation.

    PubMed

    Deng, Shubo; Zhou, Qin; Yu, Gang; Huang, Jun; Fan, Qing

    2011-02-01

    Perfluorooctanoate (PFOA) has been detected in surface water all over the world, and little is known of its removal by coagulation in water treatment plants. In this study, polyaluminium chloride (PACl) was used to remove PFOA from surface water, and the effects of coagulant dose, solution pH, temperature, and initial turbidity on the removal of both PFOA and suspended solids (SS) from water were investigated. Since the SS had high sorption affinity for PFOA, most PFOA was adsorbed on the particles and removed via the SS removal in the coagulation process. PFOA concentrations in aqueous phase decreased with increasing initial turbidity and PACl dose, while they increased with increasing solution pH and temperature. Other perfluorinated compounds (PFCs) with different C-F chain lengths and functional groups were also compared with PFOA. It was proved that hydrophobic interaction played an important role in the adsorption of PFOA on the SS. The addition of powdered activated carbon (PAC) before the coagulation process significantly enhanced the removal efficiency of PFOA in water, and the residual PFOA concentrations in water were less than 1 μg/L after the addition of 1-16 mg/L PAC and subsequent coagulation when the initial PFOA concentrations were in the range of 0.5-3 mg/L. © 2010 Elsevier Ltd. All rights reserved.

  6. Coagulation tests show significant differences in patients with breast cancer.

    PubMed

    Tas, Faruk; Kilic, Leyla; Duranyildiz, Derya

    2014-06-01

    Activated coagulation and fibrinolytic system in cancer patients is associated with tumor stroma formation and metastasis in different cancer types. The aim of this study is to explore the correlation of blood coagulation assays for various clinicopathologic factors in breast cancer patients. A total of 123 female breast cancer patients were enrolled into the study. All the patients were treatment naïve. Pretreatment blood coagulation tests including PT, APTT, PTA, INR, D-dimer, fibrinogen levels, and platelet counts were evaluated. Median age of diagnosis was 51 years old (range 26-82). Twenty-two percent of the group consisted of metastatic breast cancer patients. The plasma level of all coagulation tests revealed statistically significant difference between patient and control group except for PT (p<0.001 for all variables except for PT; p=0.08). Elderly age (>50 years) was associated with higher D-dimer levels (p=0.003). Metastatic patients exhibited significantly higher D-dimer values when compared with early breast cancer patients (p=0.049). Advanced tumor stage (T3 and T4) was associated with higher INR (p=0.05) and lower PTA (p=0.025). In conclusion, coagulation tests show significant differences in patients with breast cancer.

  7. Principles of dielectric blood coagulometry as a comprehensive coagulation test.

    PubMed

    Hayashi, Yoshihito; Brun, Marc-Aurèle; Machida, Kenzo; Nagasawa, Masayuki

    2015-10-06

    Dielectric blood coagulometry (DBCM) is intended to support hemostasis management by providing comprehensive information on blood coagulation from automated, time-dependent measurements of whole blood dielectric spectra. We discuss the relationship between the series of blood coagulation reactions, especially the aggregation and deformation of erythrocytes, and the dielectric response with the help of clot structure electron microscope observations. Dielectric response to the spontaneous coagulation after recalcification presented three distinct phases that correspond to (P1) rouleau formation before the onset of clotting, (P2) erythrocyte aggregation and reconstitution of aggregates accompanying early fibrin formation, and (P3) erythrocyte shape transformation and/or structure changes within aggregates after the stable fibrin network is formed and platelet contraction occurs. Disappearance of the second phase was observed upon addition of tissue factor and ellagic acid for activation of extrinsic and intrinsic pathways, respectively, which is attributable to accelerated thrombin generation. A series of control experiments revealed that the amplitude and/or quickness of dielectric response reflect platelet function, fibrin polymerization, fibrinolysis activity, and heparin activity. Therefore, DBCM sensitively measures blood coagulation via erythrocytes aggregation and shape changes and their impact on the dielectric permittivity, making possible the development of the battery of assays needed for comprehensive coagulation testing.

  8. Splenic hematoma in acute pancreatitis. Role of coagulation disorders.

    PubMed

    Clavé, P; Guillaumes, S; Blanco, I; Martínez de Hurtado, J; Esquius, J; Marruecos, L; Fontcuberta, J; Pérez, C; Farré, A; Lluís, F

    1992-08-01

    Splenic hematomas are infrequent complications of acute pancreatitis. In some cases, local factors that may play a role in the pathogenesis of the hematoma (thrombosis of the splenic artery or veins, intrasplenic pseudocysts, perisplenic adhesions, enzymatic digestion) are found. In the absence of local factors, the etiology of splenic hemorrhage remains unknown. We report two cases of splenic hematoma occurring during an acute necro-hemorrhagic pancreatitis associated with renal failure that required renal replacement therapy (hemodialysis and continuous arteriovenous hemodialysis). In both cases, more than half of splenic parenchyma was affected by multiple infarctions. No local factors responsible for the splenic abnormalities were detected in either case. Thrombosis of the splenic arterial microcirculation and a coagulation disorder consistent with disseminated intravascular coagulation was detected in one patient. In the second patient, coagulation disorders secondary to either liver disease, pancreatitis and its septic complications, or extracorporeal circuit heparinization for renal replacement therapy were present. Coagulation disorders should be considered whenever a splenic hematoma is found in a patient with acute pancreatitis. Disseminated intravascular coagulation may be the etiology of a splenic hematoma in acute pancreatitis.

  9. Optical coherence tomography to investigate optical properties of blood during coagulation

    NASA Astrophysics Data System (ADS)

    Xu, Xiangqun; Lin, Jia; Fu, Feifei

    2011-09-01

    This study investigates the optical properties of human blood during the coagulation process under statics using optical coherence tomography (OCT). OCT signal slope (OCTSS) and 1/e light penetration depth (d1/e) were obtained from the profiles of reflectance versus depth. Results showed that both OCTSS and d1/e were able to sensitively differentiate various stages of blood properties during coagulating. After 1 h clotting, OCTSS decreased by 47.0%, 15.0%, 13.7%, and 8.5% and d1/e increased by 34.7%, 29.4%, 24.3%, and 22.9% for the blood samples at HCT of 25%, 35%, 45%, and 55%, respectively. The slope of d1/e versus time (Sr, ×10-4 mm/s), associated with clot formation rate decreased from 6.0+/-0.3, 3.7+/-0.5 to 2.3+/-0.4 with the increasing of HCT from 35%, 45%, to 55%. The clotting time (tc) from the d1/e evolution curves was estimated to be 1969+/-92 s, 375+/-12 s, 455+/-11 s, and 865+/-47 s for the blood of 25%, 35%, 45%, and 55%. This study demonstrates that the parameters (tc and Sr) from the variations in d1/e had better sensitivity and smaller standard deviation. Furthermore, blood hematocrit affecting backscattering properties of blood during coagulation was capable of being discerned by OCT parameters. It is concluded that OCT is a potential technique to quantify and follow the liquid-gel transition of blood during clotting.

  10. Optical and thermal simulations of noninvasive laser coagulation of the human vas deferens

    NASA Astrophysics Data System (ADS)

    Schweinsberger, Gino R.; Cilip, Christopher M.; Trammell, Susan R.; Cherukuri, Harish; Fried, Nathaniel M.

    2011-03-01

    Successful noninvasive laser coagulation of the canine vas deferens, in vivo, has been previously reported. However, there is a significant difference between the optical properties of canine and human skin. In this study, Monte Carlo simulations of light transport through tissue and heat transfer simulations are performed to determine the feasibility of noninvasive laser vasectomy in humans. A laser wavelength of 1064 nm was chosen for deep optical penetration in tissue. Monte Carlo simulations determined the spatial distribution of absorbed photons inside the tissue layers (epidermis, dermis, and vas). The results were convolved with a 3-mm-diameter laser beam, and then used as the spatial heat source for the heat transfer model. A laser pulse duration of 500 ms and pulse rate of 1 Hz, and cryogen spray cooling were incident on the tissue for 60 s. Average laser power (5-9 W), cryogen pulse duration (60-100 ms), cryogen cooling rate (0.5-1.0 Hz), and increase in optical transmission due to optical clearing (0-50 %), were studied. After application of an optical clearing agent to increase skin transmission by 50%, an average laser power of 6 W, cryogen pulse duration of 60 ms, and cryogen cooling rate of 1 Hz resulted in vas temperatures of ~ 60°C, sufficient for thermal coagulation, while 1 mm of the skin surface (epidermis and dermis) remained at a safe temperature of ~ 45 °C. Monte Carlo and heat transfer simulations indicate that it is possible to noninvasively thermally coagulate the human vas without adverse effects (e.g. scrotal skin burns), if an optical clearing agent is applied to the skin prior to the procedure.

  11. Optical coherence tomography to investigate optical properties of blood during coagulation.

    PubMed

    Xu, Xiangqun; Lin, Jia; Fu, Feifei

    2011-09-01

    This study investigates the optical properties of human blood during the coagulation process under statics using optical coherence tomography (OCT). OCT signal slope (OCTSS) and 1∕e light penetration depth (d(1∕e)) were obtained from the profiles of reflectance versus depth. Results showed that both OCTSS and d(1∕e) were able to sensitively differentiate various stages of blood properties during coagulating. After 1 h clotting, OCTSS decreased by 47.0%, 15.0%, 13.7%, and 8.5% and d(1∕e) increased by 34.7%, 29.4%, 24.3%, and 22.9% for the blood samples at HCT of 25%, 35%, 45%, and 55%, respectively. The slope of d(1∕e) versus time (S(r), ×10(-4) mm∕s), associated with clot formation rate decreased from 6.0 ± 0.3, 3.7 ± 0.5 to 2.3 ± 0.4 with the increasing of HCT from 35%, 45%, to 55%. The clotting time (t(c)) from the d(1∕e) evolution curves was estimated to be 1969 ± 92 s, 375 ± 12 s, 455 ± 11 s, and 865 ± 47 s for the blood of 25%, 35%, 45%, and 55%. This study demonstrates that the parameters (t(c) and S(r)) from the variations in d(1∕e) had better sensitivity and smaller standard deviation. Furthermore, blood hematocrit affecting backscattering properties of blood during coagulation was capable of being discerned by OCT parameters. It is concluded that OCT is a potential technique to quantify and follow the liquid-gel transition of blood during clotting.

  12. Comparison of coagulation pretreatment of produced water from natural gas well by polyaluminium chloride and polyferric sulphate coagulants.

    PubMed

    Zhai, Jun; Huang, Zejin; Rahaman, Md Hasibur; Li, Yue; Mei, Longyue; Ma, Hongpu; Hu, Xuebin; Xiao, Haiwen; Luo, Zhiyong; Wang, Kunping

    2017-05-01

    This study aimed to optimise coagulation pretreatment of the produced water (PW) collected from a natural gas field. Two coagulants, polyferric sulphate (PFS) and polyaluminium chloride (PACl), were applied separately for the organics, suspended solids (SS), and colour removal. Treatment performance at different coagulant dosages, initial pH values, stirring patterns, and the addition of cationic polyacrylamide (PAM) was investigated in jar tests. The optimal coagulation conditions were dosage of PACl 25 g/L or PFS 20 g/L with that of PAM 30 mg/L, initial pH of 11, and fast mixing of 1.5 min (for PACl) or 2 min (for PFS) at 250 rpm followed by slow mixing of 15 min at 50 rpm for both coagulants. PACl performed better than PFS to remove chemical oxygen demand (COD), total organic carbon (TOC), SS, and colour, and achieved a removal efficiency of 90.1%, 89.4%, 99.0%, and 99.9%, respectively, under the optimal condition; while PFS efficiency was 86.1%, 86.1%, 99.0%, and 98.2%, respectively. However, oil removal was higher in PFS coagulation compared to PACl and showed 98.9% and 95.3%, respectively. Biodegradability, ratio of the biological oxygen demand (five-day) (BOD5)/COD, of the PW after pretreatment increased from 0.08 to 0.32 for PFS and 0.43 for PACl. Zeta potential (Z-potential) analysis at the optimum coagulant dosage of PACl and PFS suggests that charge neutralisation was the predominant mechanism during coagulation. Better efficiency was observed at higher pH. The addition of PAM and starring pattern had a minor influence on the removal performance of both coagulants. The results suggest that PACl or PFS can be applied for the pretreatment of PW, which can provide substantial removal of carbon, oil, and colour, a necessary first step for subsequent main treatment units such as chemical oxidation or biological treatment.

  13. Coagulation profile, gene expression and bioinformatics characterization of coagulation factor X of striped murrel Channa striatus.

    PubMed

    Arasu, Abirami; Kumaresan, Venkatesh; Sathyamoorthi, Akila; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah; Arockiaraj, Jesu

    2016-08-01

    A transcriptome wide analysis of the constructed cDNA library of snakehead murrel Channa striatus revealed a full length cDNA sequence of coagulation factor X. Sequence analysis of C. striatus coagulation factor X (CsFX) showed that the cDNA contained 1232 base pairs (bp) comprising 1209 bp open reading frame (ORF). The ORF region encodes 424 amino acids with a molecular mass of 59 kDa. The polypeptide contains γ-carboxyglutamic acid (GLA) rich domain and two epidermal growth factor (EGF) like domains including EGF-CA domain and serine proteases trypsin signature profile. CsFX exhibited the maximum similarity with fish species such as Stegastes partitus (78%), Poecilia formosa (76%) and Cynoglossus semilaevis (74%). Phylogenetically, CsFX is clustered together with the fish group belonging to Actinopterygii. Secondary structure of factor X includes alpha helix 28.54%, extended strand 20.75%, beta turn 7.78% and random coil 42.92%. A predicted 3D model of CsFX revealed a short α-helix and a Ca(2+) (Gla domain) binding site in the coil. Four disulfide bridges were found in serine protease trypsin profile. Obviously, the highest gene expression (P < 0.05) was noticed in blood. Further, the changes in expression of CsFX was observed after inducing with bacterial (Aeromonas hydrophila) and fungal (Aphanomyces invadans) infections and other synthetic immune stimulants. Variation in blood clotting time (CT), prothrombin time (PT) and activated prothromboplastin time (APTT) was analyzed and compared between healthy and bacterial infected fishes. During infection, PT and APTT showed a declined clotting time due to the raised level of thrombocytes.

  14. The relevance of the coagulation screen before surgery.

    PubMed

    Borges, Nuno M; Thachil, Jecko

    2017-10-02

    Coagulation testing has long been part of the routine assessment of the preoperative patient, with the aim of identifying those with a bleeding disorder who might suffer significant perioperative bleeding. Some of the issues surrounding this involve the low prevalence of bleeding disorders in the general population, and the implications of further testing for both the patient and the health-care system. Studies suggest that this practice is not evidence based and is considered to be outdated. Most guidelines now advise against routine coagulation screens before surgery, and instead recommend taking a thorough personal and family history of bleeding in order to determine the need for further investigations. This review analyses current evidence on this topic and provides a comprehensive view of the relevance of preoperative coagulation testing.

  15. Multifrequency acoustics as a probe of mesoscopic blood coagulation dynamics

    NASA Astrophysics Data System (ADS)

    Ganesan, Adarsh; Rajendran, Gokulnath; Ercole, Ari; Seshia, Ashwin

    2016-08-01

    Coagulation is a complex enzymatic polymerisation cascade. Disordered coagulation is common in medicine and may be life-threatening yet clinical assays are typically bulky and/or provide an incomplete picture of clot mechanical evolution. We present the adaptation of an in-plane acoustic wave device: quartz crystal microbalance with dissipation at multiple harmonics to determine the time-evolution of mesoscale mechanical properties of clot formation in vitro. This approach is sensitive to changes in surface and bulk clot structure in various models of induced coagulopathy. Furthermore, we are able to show that clot formation at surfaces has different kinetics and mechanical strength to that in the bulk, which may have implications for the design of bioprosthetic materials. The "Multifrequency acoustics" approach thus enables unique capability to portray biological processes concerning blood coagulation.

  16. Coagulation and survival in Drosophila melanogaster fondue mutants.

    PubMed

    Bajzek, Clara; Rice, Amy M; Andreazza, Simonetta; Dushay, Mitchell S

    2012-10-01

    Drosophila larval coagulation factors have been identified in vitro. Better understanding of insect hemolymph coagulation calls for experiments in vivo. We have characterized a fondue (fon) mutation and null alleles isolated by imprecise excision of a transposable element. Loss of fon was pupal lethal, but adults could be recovered by expressing the UAS::fonGFP construct of Lindgren et al. (2008). Despite their lethality, fon mutations did not affect larval survival after wounding either when tested alone or in combination with a mutation in the hemolectin clotting factor gene. This reinforces the idea of redundant hemostatic mechanisms in Drosophila larvae, and independent pleiotropic functions of the fondue protein in coagulation and a vital process in metamorphosis. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Home water treatment by direct filtration with natural coagulant.

    PubMed

    Babu, Raveendra; Chaudhuri, Malay

    2005-03-01

    Seeds of the plant species Strychnos potatorum and Moringa oleifera contain natural polyelectrolytes which can be used as coagulants to clarify turbid waters. In laboratory tests, direct filtration of a turbid surface water (turbidity 15-25 NTU, heterotrophic bacteria 280-500 cfu ml(-1), and fecal coliforms 280-500 MPN 100 ml(-1)), with seeds of S. potatorum or M. oleifera as coagulant, produced a substantial improvement in its aesthetic and microbiological quality (turbidity 0.3-1.5 NTU, heterotrophic bacteria 5-20 cfu ml(-1) and fecal coliforms 5-10 MPN 100 ml(-1)). The method appears suitable for home water treatment in rural areas of developing countries. These natural coagulants produce a 'low risk' water; however, additional disinfection or boiling should be practised during localised outbreaks/epidemics of enteric infections.

  18. [Extracorporeal shockwave lithotripsy in patients with coagulation disorders].

    PubMed

    Ruiz Marcellán, F J; Mauri Cunill, A; Cabré Fabré, P; Argentino Gancedo Rodríguez, V; Güell Oliva, J A; Ibarz Servio, L; Ramón Dalmau, M

    1992-03-01

    During treatment of renal lithiasis with extracorporeal shock wave lithotripsy (ESWL) hemorrhagic events, especially renal hematoma, may present. A coagulation study is warranted in order to institute hemotherapy for blood factor deficiencies. We reviewed the records of 4,000 patients that had undergone ESWL. Of these, 17 (12 males, 5 females) presented coagulation disorders. The bleeding diatheses were due to platelet deficiency in 6 cases, plasma defects in 5, platelet and plasma disorders in 2, and capillary wall defects in 5 cases. The underlying cause was hepatosplenic disease in 12 cases, iatrogenic in 1, connectivopathy and corticoids in 2, and capillary purpura of unknown cause in 2 cases. Due to this protocol, no patient presented hemorrhage or hematoma from shock wave-induced lesions. These results show that a complete coagulation study must be performed in order to institute the necessary measures in patients with disorders of hemostasis due to the high risk of hematoma repeatedly reported in the literature.

  19. How hemostatic agents interact with the coagulation cascade.

    PubMed

    Overbey, Douglas M; Jones, Edward L; Robinson, Thomas N

    2014-08-01

    Hemostasis is a critical component of the preservation of hemodynamic stability and operative visibility during surgery. Initially, hemostasis is achieved via the careful application of direct pressure to allow time for the coagulation cascade to create a fibrin and platelet plug. Other first-line methods of hemostasis in surgery include repair or ligation of the bleeding vessel with sutures, clips, or staples and coagulation of the bleeding site with a thermal energy-based device. When these methods are insufficient to provide adequate hemostasis, topical hemostatic agents can be used to augment the creation of a clot during surgery. A basic understanding of how and where these products interact with the coagulation cascade is essential to achieving optimal hemostasis outcomes.

  20. Mathematical Modeling of Intravascular Blood Coagulation under Wall Shear Stress

    PubMed Central

    Rukhlenko, Oleksii S.; Dudchenko, Olga A.; Zlobina, Ksenia E.; Guria, Georgy Th.

    2015-01-01

    Increased shear stress such as observed at local stenosis may cause drastic changes in the permeability of the vessel wall to procoagulants and thus initiate intravascular blood coagulation. In this paper we suggest a mathematical model to investigate how shear stress-induced permeability influences the thrombogenic potential of atherosclerotic plaques. Numerical analysis of the model reveals the existence of two hydrodynamic thresholds for activation of blood coagulation in the system and unveils typical scenarios of thrombus formation. The dependence of blood coagulation development on the intensity of blood flow, as well as on geometrical parameters of atherosclerotic plaque is described. Relevant parametric diagrams are drawn. The results suggest a previously unrecognized role of relatively small plaques (resulting in less than 50% of the lumen area reduction) in atherothrombosis and have important implications for the existing stenting guidelines. PMID:26222505

  1. Compact self-contained blood coagulator based on semiconductor laser

    NASA Astrophysics Data System (ADS)

    Svirin, Vaytcheslav N.; Rogatkin, Dmitrii A.; Chernenko, P.

    2001-01-01

    In recent years significant improvement of power and spectral characteristics of semiconductor lasers has taken place. The power of serial single near-IR semiconductor lasers has achieved units of watts, the spectral range has been extended from 0.63 to 1.7...1.8 micrometers . The available level of semiconductor lasers, their small dimensions and weight, together with the characteristics of the modern fiberoptic systems, electronic and microprocessor components as well as small dimensions and weight of modern power supplies allow development of a compact portable self-contained blood coagulator, which is of great importance for use in various emergencies, natural calamities, and in many other areas. The report discusses the problems of designing the coagulator, its technical and user characteristics as well as the possibilities to use such a coagulator in other fields of laser medicine.

  2. Effect of Coagulation of Nodes in an Evolving Complex Network

    NASA Astrophysics Data System (ADS)

    Miura, Wataru; Takayasu, Hideki; Takayasu, Misako

    2012-04-01

    We propose a new type of stochastic network evolution model based on annihilation, creation, and coagulation of nodes, together with the preferential attachment rule. The system reaches a unique quasistatistically steady state in which the distribution of links follows a power law, lifetime of nodes follows an exponential distribution, and the mean number of links grows exponentially with time. The master equation of the model is solved analytically by applying Smoluchowski’s coagulation equation for aerosols. The results indicate that coagulation of nodes in complex networks and mean field analysis of aerosols are similar in both the growth dynamics with irreversible processes and in the steady state statistics. We confirm that the basic properties of the model are consistent with the empirical results of a business transaction network having about 1×106 firms.

  3. Coagulation management in trauma-associated coagulopathy: allogenic blood products versus coagulation factor concentrates in trauma care.

    PubMed

    Klages, Matthias; Zacharowski, Kai; Weber, Christian Friedrich

    2016-04-01

    Coagulation management by transfusion of allogenic blood products and coagulation factors are competing concepts in current trauma care. Rapid and adequate therapy of trauma-associated coagulopathy is crucial to survival of severely injured patients. Standard coagulation tests such as prothrombin time and activated partial thromboplastin time are commonly used, but these tests are inappropriate for monitoring and guiding therapy in trauma patients. Coagulation factor-based treatment showed promising results, but randomized trials have not yet been performed. In addition, viscoelastic tests are needed to guide therapy, although there is in fact limited evidence for these in tests in trauma care. Regarding transfusion therapy with allogenic blood products, plasma transfusion has been associated with improved survival in trauma patients following massive transfusion. In contrast, patients not requiring massive transfusion seem to be at risk for suffering complications with increasing volumes of plasma transfused. The collective of trauma patients is heterogeneous. Despite the lack of evidence, there are strong arguments for individualized patient treatment with coagulation factors for some indications and to abstain from the use of fresh frozen plasma. In patients with severe trauma and major bleeding, plasma, platelets, and red blood cells should be considered to be administered at a ratio of 1 : 1 : 1.

  4. Properties and coagulation performance of coagulant poly-aluminum-ferric-silicate-chloride in water and wastewater treatment.

    PubMed

    Gao, Bao-yu; Yue, Qin-yan; Wang, Bing-jian

    2006-01-01

    An efficient inorganic polymer coagulant, poly-aluminum-ferric-silicate-chloride (PAFSC), was developed using two approaches: (i) hydroxylation of the mixture of AlCl3, FeCl3 and fresh polysilicic acid in different Al/Fe/Si molar ratios to obtain PAFSCc and (ii) hydroxylated poly-aluminum-iron-chloride (PAFC) combined with aged polysilicic acid in different Al/Fe/Si ratios to produce PAFSCm. The properties of PAFSC in comparison with polyaluminum silicate chloride (PASC) and polyferric silicate chloride (PAFC) were characterized by various experimental methods. The effect of Al/Fe/Si molar ratio on the hydrolysis-polymerization process of Al (III) and Fe (III) in PAFSC solutions was examined by pH titration, and the effect of Al/Fe/Si molar ratio on electrokinetic mobility of PAFSC was studied by Zeta potential measurement. The laboratory experiments were performed to evaluate the PAFSC in comparison with polyaluminum chloride (PAC) for the coagulation of synthetic water samples, actual surface water and wastewater. The results show that interactions exist among aluminum species, ferric species and polysilicic acid, and the Al/Fe/Si molar ratio affects the Zeta potential of the hydrolyzate and the coagulating performance. PAFSC achieved a better water treatment result than PAC. At the same basicity (B) value and Al/Fe/Si ratio, PAFSCc has better coagulation performance than PAFSCm. PAFSC is a new type and high efficiency composite inorganic polymer coagulant.

  5. Characteristics of meso-particles formed in coagulation process causing irreversible membrane fouling in the coagulation-microfiltration water treatment.

    PubMed

    Ding, Q; Yamamura, H; Murata, N; Aoki, N; Yonekawa, H; Hafuka, A; Watanabe, Y

    2016-09-15

    In coagulation-membrane filtration water treatment processes, it is still difficult to determine the optimal coagulation condition to minimize irreversible membrane fouling. In microfiltration (MF), meso-particles (i.e., 20 nm-0.5 μm) are thought to play an important role in irreversible membrane fouling, especially their characteristics of particle number (PN) and zeta potential (ZP). In this study, a new nanoparticle tracker combined a high-output violet laser with a microscope was developed to identify the physicochemical characteristics of these microscopic and widely dispersed meso-particles. The effects of pH and coagulant dose on ZP and PN of micro-particles (i.e., >0.5 μm) and meso-particles were investigated, and then coagulation-MF tests were conducted. As the result, irreversible membrane fouling was best controlled for both types of membranes, while meso-particle ZP approached zero at around pH 5.5 for both types of natural water. Since PN was greatest under these conditions, ZP is more important in determining the extent of irreversible membrane fouling than PN. However, the acidic condition to neutralize meso-particles is not suitable for actual operation, as considering residual aluminum concentration, pipe corrosion, and chlorination efficiency. It is therefore necessary to investigate coagulants or other methods for the appropriate modification of meso-particle characteristics.

  6. Enhanced WWTP effluent organic matter removal in hybrid ozonation-coagulation (HOC) process catalyzed by Al-based coagulant.

    PubMed

    Jin, Xin; Jin, Pengkang; Hou, Rui; Yang, Lei; Wang, Xiaochang C

    2017-04-05

    A novel hybrid ozonation-coagulation (HOC) process was developed for application in wastewater reclamation. In this process, ozonation and coagulation occurred simultaneously within a single unit. Compared with the conventional pre-ozonation-coagulation process, the HOC process exhibited much better performance in removing dissolved organic matters. In particular, the maximal organic matters removal efficiency was obtained at the ozone dosage of 1mgO3/mg DOC at each pH value (pH 5, 7 and 9). In order to interpret the mechanism of the HOC process, ozone decomposition was monitored. The results indicated that ozone decomposed much faster in the HOC process. Moreover, by using the reagent of O3-resistant hydroxyl radical (OH) probe compound, para-chlorobenzoic acid (pCBA), and electron paramagnetic resonance (EPR) analysis, it was observed that the HOC process generated higher content of OH compared with pre-ozonation process. This indicates that the OH oxidation reaction as the key step can be catalyzed and enhanced by Al-based coagulants and their hydrolyzed products in this developed process. Thus, based on the catalytic effects of Al-based coagulants on ozonation, the HOC process provides a promising alternative to the conventional technology for wastewater reclamation in terms of higher efficiency. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Biological and analytical variations of 16 parameters related to coagulation screening tests and the activity of coagulation factors.

    PubMed

    Chen, Qian; Shou, Weiling; Wu, Wei; Guo, Ye; Zhang, Yujuan; Huang, Chunmei; Cui, Wei

    2015-04-01

    To accurately estimate longitudinal changes in individuals, it is important to take into consideration the biological variability of the measurement. The few studies available on the biological variations of coagulation parameters are mostly outdated. We confirmed the published results using modern, fully automated methods. Furthermore, we added data for additional coagulation parameters. At 8:00 am, 12:00 pm, and 4:00 pm on days 1, 3, and 5, venous blood was collected from 31 healthy volunteers. A total of 16 parameters related to coagulation screening tests as well as the activity of coagulation factors were analyzed; these included prothrombin time, fibrinogen (Fbg), activated partial thromboplastin time, thrombin time, international normalized ratio, prothrombin time activity, activated partial thromboplastin time ratio, fibrin(-ogen) degradation products, as well as the activity of factor II, factor V, factor VII, factor VIII, factor IX, and factor X. All intraindividual coefficients of variation (CVI) values for the parameters of the screening tests (except Fbg) were less than 5%. Conversely, the CVI values for the activity of coagulation factors were all greater than 5%. In addition, we calculated the reference change value to determine whether a significant difference exists between two test results from the same individual.

  8. Obstetric hemorrhage and coagulation: an update. Thromboelastography, thromboelastometry, and conventional coagulation tests in the diagnosis and prediction of postpartum hemorrhage.

    PubMed

    de Lange, Natascha M; Lancé, Marcus D; de Groot, Reneé; Beckers, Erik A M; Henskens, Yvonne M; Scheepers, Hubertina C J

    2012-07-01

    Globally, postpartum hemorrhage (PPH) is the leading cause of maternal morbidity and mortality. In the current treatment of severe PPH, first-line therapy includes transfusion of packed cells and fresh-frozen plasma in addition to uterotonic medical management and surgical interventions. In persistent PPH, tranexamic acid, fibrinogen, and coagulation factors are often administered. Secondary coagulopathy due to PPH or its treatment is often underestimated and therefore remains untreated, potentially causing progression to even more severe PPH. In most cases, medical and transfusion therapy is not based on the actual coagulation state because conventional laboratory test results are usually not available for 45 to 60 minutes. Thromboelastography and rotational thromboelastometry are point-of-care coagulation tests. A good correlation has been shown between thromboelastometric and conventional coagulation tests, and the use of these in massive bleeding in nonobstetric patients is widely practiced and it has been proven to be cost-effective. As with conventional laboratory tests, there is an influence of fluid dilution on coagulation test results, which is more pronounced with colloid fluids. Fibrinogen seems to play a major role in the course of PPH and can be an early predictor of the severity of PPH. The FIBTEM values (in thromboelastometry, reagent specific for the fibrin polymerization process) decline even more rapidly than fibrinogen levels and can be useful for early guidance of interventions. Data on thromboelastography and thromboelastometry in pregnant women are limited, particularly during the peripartum period and in women with PPH, so more research in this field is needed.

  9. Optical properties measurement of laser coagulated tissues with double integrating sphere and inverse Monte Carlo technique in the wavelength range from 350 to 2100 nm

    NASA Astrophysics Data System (ADS)

    Honda, Norihiro; Nanjo, Takuya; Ishii, Katsunori; Awazu, Kunio

    2012-03-01

    In laser medicine, the accurate knowledge about the optical properties (absorption coefficient; μa, scattering coefficient; μs, anisotropy factor; g) of laser irradiated tissues is important for the prediction of light propagation in tissues, since the efficacy of laser treatment depends on the photon propagation within the irradiated tissues. Thus, it is likely that the optical properties of tissues at near-ultraviolet, visible and near-infrared wavelengths will be more important due to more biomedical applications of lasers will be developed. For improvement of the laser induced thermotherapy, the optical property change during laser treatment should be considered in the wide wavelength range. For estimation of the optical properties of the biological tissues, the optical properties measurement system with a double integrating sphere setup and an inverse Monte Carlo technique was developed. The optical properties of chicken muscle tissue were measured in the native state and after laser coagulation using the optical properties measurement system in the wavelength range from 350 to 2100 nm. A CO2 laser was used for laser coagulation. After laser coagulation, the reduced scattering coefficient of the tissue increased. And, the optical penetration depth decreased. For improvement of the treatment depth during laser coagulation, a quantitative procedure using the treated tissue optical properties for determination of the irradiation power density following light penetration decrease might be important in clinic.

  10. Treatment of desizing wastewater by catalytic thermal treatment and coagulation.

    PubMed

    Kumar, Pradeep; Prasad, B; Chand, Shri

    2009-04-15

    In the present study, the coagulation of the fresh and thermally treated desizing wastewater has been reported. The maximum COD reduction of fresh desizing wastewater using coagulation was observed with commercial alum at initial pH 4. This was followed by aluminum potassium sulfate (pH 4), FeCl(3) (pH 6), PAC (pH 6) and FeSO(4) (pH 4). The maximum COD reduction observed at a coagulant (commercial alum) dose of 5 kg/m(3) and pH 4 was 58% whereas the color reduction at these conditions was 85%. The results reveal that the application of coagulation on the catalytic thermal treated effluent is more effective in removing nearly 88% of COD and 96% of color at above mentioned conditions except at a coagulant dose of 1 kg/m(3). The amount of inorganic sludge generated gets drastically reduced (almost 25%) due to the reduced amount of coagulant. The COD and color of the final effluent were found to be 98.6 mg/l and 2.67 PCU, respectively, and the COD/BOD(3) ratio was 1.36. The settling rate of the slurry was found to be strongly influenced by treatment pH. The slurry obtained after treatment at pH 12 settled faster in comparison to slurry obtained at pH 4. The filterability of the treated effluent is also strongly dependent on pH. pH 12 was adjudged to be the best in giving highest filtration rate.

  11. Adaptive force sonorheometry for assessment of whole blood coagulation.

    PubMed

    Mauldin, F William; Viola, Francesco; Hamer, Theresa C; Ahmed, Eman M; Crawford, Shawna B; Haverstick, Doris M; Lawrence, Michael B; Walker, William F

    2010-05-02

    Viscoelastic diagnostics that monitor the hemostatic function of whole blood (WB), such as thromboelastography, have been developed with demonstrated clinical utility. By measuring the cumulative effects of all components of hemostasis, viscoelastic diagnostics have circumvented many of the challenges associated with more common tests of blood coagulation. We describe a new technology, called sonorheometry, that adaptively applies acoustic radiation force to assess coagulation function in WB. The repeatability (precision) of coagulation parameters was assessed using citrated WB samples. A reference range of coagulation parameters, along with corresponding measurements from prothrombin time (PT) and partial thromboplastin time (PTT), were obtained from WB samples of 20 healthy volunteers. In another study, sonorheometry monitored anticoagulation with heparin (0-5 IU/ml) and reversal from varied dosages of protamine (0-10 IU/ml) in heparinized WB (2 IU/ml). Sonorheometry exhibited low CVs for parameters: clot initiation time (TC1), <7%; clot stabilization time (TC2), <6.5%; and clotting angle (theta), <3.5%. Good correlation was observed between clotting times, TC1 and TC2, and PTT (r=0.65 and 0.74 respectively; n=18). Linearity to heparin dosage was observed with average linearity r>0.98 for all coagulation parameters. We observed maximum reversal of heparin anticoagulation at protamine to heparin ratios of 1.4:1 from TC1 (P=0.6) and 1.2:1 from theta (P=0.55). Sonorheometry is a non-contact method for precise assessment of WB coagulation. Copyright 2010 Elsevier B.V. All rights reserved.

  12. Adaptive Force Sonorheometry for Assessment of Whole Blood Coagulation

    PubMed Central

    Mauldin, F. William; Viola, Francesco; Hamer, Theresa C.; Ahmed, Eman M.; Crawford, Shawna B.; Haverstick, Doris M.; Lawrence, Michael B.; Walker, William F.

    2010-01-01

    Background: Viscoelastic diagnostics that monitor the hemostatic function of whole blood (WB), such as thromboelastography, have been developed with demonstrated clinical utility. By measuring the cumulative effects of all components of hemostasis, viscoelastic diagnostics have circumvented many of the challenges associated with more common tests of blood coagulation. Methods: We describe a new technology, called sonorheometry, that adaptively applies acoustic radiation force to assess coagulation function in WB. The repeatability (precision) of coagulation parameters was assessed using citrated WB samples. A reference range of coagulation parameters, along with corresponding measurements from prothrombin time (PT) and partial thromboplastin time (PTT), were obtained from WB samples of 20 healthy volunteers. In another study, sonorheometry monitored anticoagulation with heparin (0 – 5 IU/ml) and reversal from varied dosages of protamine (0 – 10 IU/ml) in heparinized WB (2 IU/ml). Results: Sonorheometry exhibited low CVs for parameters: clot initiation time (TC1), < 7%; clot stabilization time (TC2), < 6.5%; and clotting angle (θ), < 3.5%. Good correlation was observed between clotting times, TC1 and TC2, and PTT (r = 0.65 and 0.74 respectively; n=18). Linearity to heparin dosage was observed with average linearity r > 0.98 for all coagulation parameters. We observed maximum reversal of heparin anticoagulation at protamine to heparin ratios of 1.4:1 from TC1 (P=0.6) and 1.2:1 from θ (P=0.55). Conclusions: Sonorheometry is a non-contact method for precise assessment of WB coagulation. PMID:20096680

  13. Sonoclot(®)-based method to detect iron enhanced coagulation.

    PubMed

    Nielsen, Vance G; Henderson, Jon

    2016-07-01

    Thrombelastographic methods have been recently introduced to detect iron mediated hypercoagulability in settings such as sickle cell disease, hemodialysis, mechanical circulatory support, and neuroinflammation. However, these inflammatory situations may have heme oxygenase-derived, coexistent carbon monoxide present, which also enhances coagulation as assessed by the same thrombelastographic variables that are affected by iron. This brief report presents a novel, Sonoclot-based method to detect iron enhanced coagulation that is independent of carbon monoxide influence. Future investigation will be required to assess the sensitivity of this new method to detect iron mediated hypercoagulability in clinical settings compared to results obtained with thrombelastographic techniques.

  14. Reincarnation of ancient links between coagulation and complement.

    PubMed

    Conway, E M

    2015-06-01

    Throughout evolution, organisms have developed means to contain wounds by simultaneously limiting bleeding and eliminating pathogens and damaged host cells via the recruitment of innate defense mechanisms. Disease emerges when there is unchecked activation of innate immune and/or coagulation responses. A key component of innate immunity is the complement system. Concurrent excess activation of coagulation and complement - two major blood-borne proteolytic pathways - is evident in numerous diseases, including atherosclerosis, diabetes, venous thromboembolic disease, thrombotic microangiopathies, arthritis, cancer, and infectious diseases. Delineating the cross-talk between these two cascades will uncover novel therapeutic insights.

  15. Extremely refractory Kawasaki disease with disseminated intravascular coagulation.

    PubMed

    Koh, Young Kwon; Lee, Jae Hee; Park, Yeong Bong

    2017-03-07

    Disseminated intravascular coagulation is a rare complication of Kawasaki disease and appears in <0.1% of Kawasaki disease patients. We report a case of refractory Kawasaki disease complicated with disseminated intravascular coagulation and giant coronary aneurysm. A 5-month-old boy presented with Kawasaki disease with coagulopathy. Although the coagulopathy improved after fresh-frozen plasma and antithrombin-III administration, the fever persisted despite two rounds of intravenous immunoglobulin, along with intravenous methylprednisolone pulse therapy and infliximab administration. Despite all efforts to treatment, the patient had giant coronary aneurysms and died suddenly.

  16. Anti-coagulant activity of plants: mini review.

    PubMed

    Akram, Muhammad; Rashid, Abid

    2017-09-02

    Medicinal plants have been used for treatment of human ailments since ancient times. Objective of this study is to document the effect of herbal drugs on anticoagulant therapy. The material for this review was taken mostly from PubMed and the Cochrane database of systematic reviews. Some other relevant references were collected from personal database of papers on anti-coagulant properties of plants. Literature review shows that many plants such as Thymus vulgaris, Cyamopsis tetragonoloba taub, Pulmonaria officinalis and Cinnamomum cassia etc have anti-coagulant activity. This review shows that medicinal plants should be prescribed with care to patients on anticoagulant therapy.

  17. Interpretation of coagulation test results under direct oral anticoagulants.

    PubMed

    Mani, H

    2014-06-01

    Diagnostic of global coagulation parameters is part of the daily clinical routine practice in conservative as well in operative disciplines. The correct interpretation of in vitro test results in context to the ex vivo influence of anticoagulant drugs and the in vivo hemostatic system of the individual patient is dependent on the doctors clinical and laboratory experience. This article shortly reviews the laboratory interference of oral anticoagulants including the target-specific inhibitors dabigatran, rivaroxaban and apixaban on coagulation parameters and discusses the potential of several methods for measuring the anticoagulant effect of the direct oral anticoagulants.

  18. Sex Differences in Stroke: The Contribution of Coagulation

    PubMed Central

    Roy-O’Reilly, Meaghan; McCullough, Louise D.

    2014-01-01

    Stroke is now the leading cause of adult disability in the United States. Women are disproportionately affected by stroke. Women increasingly outnumber men in the elderly population, the period of highest risk for stroke. However, there is also a growing recognition that fundamental sex differences are present that contribute to differential ischemic sensitivity. In addition, gonadal hormone exposure can impact coagulation and fibrinolysis, key factors in the initiation of thrombosis. In this review we will discuss sex differences in stroke, with a focus on platelets, vascular reactivity and coagulation. PMID:24560819

  19. Strongly differentiable solutions of the discrete coagulation-fragmentation equation

    NASA Astrophysics Data System (ADS)

    McBride, A. C.; Smith, A. L.; Lamb, W.

    2010-08-01

    We examine an infinite system of ordinary differential equations that models the binary coagulation and multiple fragmentation of clusters. In contrast to previous investigations, our analysis does not involve finite-dimensional truncations of the system. Instead, we treat the problem as an infinite-dimensional differential equation, posed in an appropriate Banach space, and apply perturbation results from the theory of strongly continuous semigroups of operators. The existence and uniqueness of physically meaningful solutions are established for uniformly bounded coagulation rates but with no growth restrictions imposed on the fragmentation rates.

  20. Ipomoea dasysperma seed gum: an effective natural coagulant for the decolorization of textile dye solutions.

    PubMed

    Sanghi, Rashmi; Bhattacharya, Bani; Dixit, Awantika; Singh, Vandana

    2006-10-01

    An investigation of dye decolorization from synthetic dye solutions using the non-ionic, water-soluble, high molecular weight seed gums Ipomoea dasysperma and guar gum as coagulants was undertaken. The use of galactomannans derived from plants in this system presents a sustainable method of textile effluent treatment. These natural coagulants extracted from plants proved to be workable alternatives to conventional coagulants like polyaluminum chloride, as they are biodegradable, safe to human health, are cost effective when compared to imported chemicals and have a wider effective dosage range for flocculation of various colloidal suspensions. Coagulant dose and coagulation pH are important factors influencing the mechanism of coagulation. Also the type and chemical structure of the dye plays an important role in the coagulation process. The seed gums alone were found to be effective for decolorization of direct dye and in combination with PAC their coagulation efficiency was well extended even for reactive and acid dyes.

  1. Red blood cell coagulation induced by low-temperature plasma treatment.

    PubMed

    Miyamoto, Kenji; Ikehara, Sanae; Takei, Hikaru; Akimoto, Yoshihiro; Sakakita, Hajime; Ishikawa, Kenji; Ueda, Masashi; Ikeda, Jun-Ichiro; Yamagishi, Masahiro; Kim, Jaeho; Yamaguchi, Takashi; Nakanishi, Hayao; Shimizu, Tetsuji; Shimizu, Nobuyuki; Hori, Masaru; Ikehara, Yuzuru

    2016-09-01

    Low-temperature plasma (LTP) treatment promotes blood clot formation by stimulation of the both platelet aggregation and coagulation factors. However, the appearance of a membrane-like structure in clots after the treatment is controversial. Based on our previous report that demonstrated characteristics of the form of coagulation of serum proteins induced by LTP treatment, we sought to determine whether treatment with two plasma instruments, namely BPC-HP1 and PN-110/120TPG, formed clots only from red blood cells (RBCs). LTP treatment with each device formed clots from whole blood, whereas LTP treatment with BPC-HP1 formed clots in phosphate-buffered saline (PBS) containing 2 × 10(9)/mL RBCs. Light microscopic analysis results showed that hemolysis formed clots consisting of materials with membrane-like structures from both whole blood and PBS-suspended RBCs. Moreover, electron microscopic analysis results showed a monotonous material with high electron density in the formed clots, presenting a membrane-like structure. Hemolysis disappeared with the decrease in the current through the targets contacting with the plasma flare and clot formation ceased. Taken together, our results and those of earlier studies present two types of blood clot formation, namely presence or absence of hemolysis capability depending on the current through the targets. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Characterization and literature review of bowel perforation injuring using argon beam coagulation

    NASA Astrophysics Data System (ADS)

    Barnes, Kelli S.; Merchel, Renée. A.; Taylor, Kenneth D.

    2015-03-01

    INTRODUCTION: Argon Beam Coagulation (ABC®) technology is used in conjunction with the ConMed ABCFlex® Probe to provide non-contact hemostasis, coagulation, and tissue devitalization during endoscopic procedures. ABC provides a superficial tissue effect; however, there is a risk of bowel perforation. To better understand the settings that lead to perforation, this study reviews the literature and provides an ex vivo characterization of the ABCFlex Probe tissue effect at different settings when used at small distances. METHODS: Depth of thermal tissue effect was characterized to determine the effect of three parameters: power (W), distance from probe tip to tissue (mm) and application duration (s). 3 ABCFlex Probes were used to create 15 samples on ex vivo porcine small intestine for each combination of parameters. The depth of tissue effect for each sample was measured using a light microscope. RESULTS: Depth of tissue effect increases as power and application time increases. An increase of distance from the probe tip to the tissue results in a decrease in depth of tissue effect from a near contact to 1mm distance. Depth of tissue effect doesn't significantly change from 1mm to 3mm distance. CONCLUSION: ABCFlex Probe can be used to achieve hemostasis in endoscopic procedures. Increasing power and application time increases the depth of thermal effect while increasing distance from the probe time to the surface of the tissue decreases the depth of tissue effect.

  3. Nanoparticles in wastewater from a science-based industrial park - coagulation using polyaluminum chloride.

    PubMed

    Chang, M R; Lee, D J; Lai, J Y

    2007-12-01

    The Hsinchu Science-based Industrial Park (HSIP) is the hi-tech manufacturing hub of Taiwan. Wastewater from the HSIP contains numerous nano-sized silicate particles whose size distributions peak at 2 and 90 nm. A 3-5 mg l(-1) as Al dose of polyaluminum chloride (PACl) was used in the field to coagulate these particles, but the removal efficiency was low. Laboratory scale tests indicated that although PACl coagulation removed 52% of the turbidity and 48% of the chemical oxygen demand (COD) from water, its effect on nano-particle removal was minimal. About 58% of the soluble COD was associated with colloidal Si particles. A light scattering test and transmission electron microscopy (TEM) demonstrated that the nano-particles agglomerated in approximately linear aggregates of sizes 100-300 nm. Prolonged contact between residual PACl and the nano-particles generated large aggregates with sizes of up to 10 microm and a fractal dimension of 2.24-2.63. The results presented herein should be of interest in the processing of "high-tech" wastewater that contains nanosized silica particles.

  4. Group D prothrombin activators from snake venom are structural homologues of mammalian blood coagulation factor Xa.

    PubMed Central

    Rao, Veena S; Joseph, Jeremiah S; Kini, R Manjunatha

    2003-01-01

    Procoagulant venoms of several Australian elapids contain proteinases that specifically activate prothrombin; among these, Group D activators are functionally similar to coagulation factor Xa (FXa). Structural information on this class of prothrombin activators will contribute significantly towards understanding the mechanism of FXa-mediated prothrombin activation. Here we present the purification of Group D prothrombin activators from three Australian snake venoms (Hoplocephalus stephensi, Notechis scutatus scutatus and Notechis ater niger) using a single-step method, and their N-terminal sequences. The N-terminal sequence of the heavy chain of hopsarin D (H. stephensi) revealed that a fully conserved Cys-7 was substituted with a Ser residue. We therefore determined the complete amino acid sequence of hopsarin D. Hopsarin D shows approximately 70% similarity with FXa and approximately 98% similarity with trocarin D, a Group D prothrombin activator from Tropidechis carinatus. It possesses the characteristic Gla domain, two epidermal growth factor-like domains and a serine proteinase domain. All residues important for catalysis are conserved, as are most regions involved in interactions with factor Va and prothrombin. However, there are some structural differences. Unlike FXa, hopsarin D is glycosylated in both its chains: in light-chain residue 52 and heavy-chain residue 45. The glycosylation on the heavy chain is a large carbohydrate moiety adjacent to the active-site pocket. Overall, hopsarin D is structurally and functionally similar to mammalian coagulation FXa. PMID:12403650

  5. The Coagulant Type Influence on Removal Efficiency of 5- and 6-Ring Pahs During Water Coagulation Process

    NASA Astrophysics Data System (ADS)

    Nowacka, Anna; Włodarczyk-Makuła, Maria

    2014-12-01

    The article presents results on investigation of the removal efficiency of selected 5- and 6-ring polycyclic aromatic hydrocarbons (benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[j]fluoranthene, benzo[g,h,i]perylene, indeno[1,2,3-cd]pyrene, dibenzo[a,h]anthracene) from water during coagulation and sedimentation process. Two pre-hydrolyzed aluminum coagulants: PAX XL 19H and FLOKOR 105V were chosen for research. Process was carried out at optimum process parameters: rapid-mixing - 3 min at the rotational speed of 200 rpm, slow mixing - 10 min at 30 rpm, sedimentation - 60 min. The removal effectiveness was dependant on coagulant type and its composition. Better results in the removal of 5-and 6-ring PAHs were obtained after application of FLOKOR 105V (lower aluminum content) than after using PAX XL 19H.

  6. Demonstration of the Coagulation and Diffusion of Homemade Slime Prepared under Acidic Conditions without Borate

    ERIC Educational Resources Information Center

    Isokawa, Naho; Fueda, Kazuki; Miyagawa, Korin; Kanno, Kenichi

    2015-01-01

    Poly(vinyl alcohol) (PVA) precipitates in many kinds of aqueous salt solutions. While sodium sulfate, a coagulant for PVA fiber, precipitates PVA to yield a white rigid gel, coagulation of PVA with aluminum sulfate, a coagulant for water treatment, yields a slime-like viscoelastic fluid. One type of homemade slime is prepared under basic…

  7. Demonstration of the Coagulation and Diffusion of Homemade Slime Prepared under Acidic Conditions without Borate

    ERIC Educational Resources Information Center

    Isokawa, Naho; Fueda, Kazuki; Miyagawa, Korin; Kanno, Kenichi

    2015-01-01

    Poly(vinyl alcohol) (PVA) precipitates in many kinds of aqueous salt solutions. While sodium sulfate, a coagulant for PVA fiber, precipitates PVA to yield a white rigid gel, coagulation of PVA with aluminum sulfate, a coagulant for water treatment, yields a slime-like viscoelastic fluid. One type of homemade slime is prepared under basic…

  8. Wet spinning of silk polymer. I. Effect of coagulation conditions on the morphological feature of filament.

    PubMed

    Um, In Chul; Kweon, HaeYong; Lee, Kwang Gill; Ihm, Dae Woo; Lee, Jang-Hern; Park, Young Hwan

    2004-04-01

    Regenerated silk fibroin (SF) filaments were prepared by the wet spinning technique. The effect of coagulation conditions, such as coagulant type and coagulation temperature, was investigated on the morphological feature of SF filaments and a theoretical approach was also performed to understand the coagulation phenomena. SEM observation revealed that as the R group size of alcoholic coagulant (ROH) increased, the cross-sectional shape deviated more from a circular form. This is attributed to the fact that as the R group size increased, the mass transfer rate difference increased, but the coagulation rate decreased due to a reduced diffusion rate. Most non-alcoholic coagulants exhibited this circular cross-sectional shape, except dioxane, which showed a clover shape. As the coagulation bath temperature increased, the cross-section deviated less from a circular form, with the reduction of fiber diameter. When methanol/water mixture was used as a coagulant, an ellipse or a dog-bone shape was obtained with higher water content in methanol, which was attributed to the decrease of coagulation rate. Although methanol exhibited a positive value of mass transfer rate difference, a circular shape of cross-section was obtained due to the density difference of the coagulated and uncoagulated parts in the coagulating SF filament. Copyright 2004 Elsevier B.V.

  9. Optical properties of normal and thermally coagulated chicken liver tissue measured ex-vivo with diffuse reflectance

    NASA Astrophysics Data System (ADS)

    Hafeez-Ullah; Atif, M.; Firdous, S.; Mehmood, M. S.; Hamza, M. Y.; Imran, M.; Hussain, G.; Ikram, M.

    2011-02-01

    The purpose of the present study is to determine the optical properties of normal and thermally coagulated chicken liver at 720, 740, 770, 810, 825 and 840 nm wavelengths of laser irradiation. So, we were able to evaluate these optical properties (absorption and scattering coefficients) with ex-vivo study using Kubelka Munk Model (KMM) from the radial dependence of the diffuse reflectance with femtosecond pulsed laser in near IR region. These coefficients were significantly increased with coagulation. The penetration depths of the diffused light have been reported to a maximum value of 8.12 ± 0.36 mm in normal liver and 2.49 ± 0.17 mm in coagulated liver at 840 nm showing increasing behavior towards IR region. The Monte Carlo simulation was used to check the theoretical validation of measured optical properties of the tissue that showed a good match with our experimental results. We believe that these differences in optical properties will be helpful for the understanding arid optimal use of laser applications in medicine and differential diagnosis of tissues by using different optical methods. Especially for the investigation of biological tissue for photodynamic therapy (PDT), the knowledge of the specific optical properties and their thermo-induced changes is important.

  10. Diode lasers for interstitial laser coagulation of the prostate

    NASA Astrophysics Data System (ADS)

    Muschter, Rolf; Perlmutter, Aaron P.; Anson, K.; Jahnen, P.; Vargas Stuve, Juan C.; Razvi, Hassan A.; Sroka, Ronald; Hofstetter, Alfons G.; Vaughan, Darracott E., Jr.

    1995-05-01

    The concept of interstitial laser coagulation (ILC) of the prostate is the generation of intraprostatic lesions of large volumes, which secondarily are resorbed. In previously published experimental and clinical studies Nd:YAG lasers in combination with specially designed light guides were used. The aim of this study was to examine the suitability of diode lasers to be used in ILC. Diode lasers of various wavelengths (805 nm, 830 nm, 950 nm and 980 nm) with different interstitial applicators (predominantly diffusor tips) were tested in vitro (potatoes, turkey muscle, porcine liver) and in vivo (canine prostate). In vitro experiments were done with various powers and radiation times in order to evaluate the maximum lesion size achievable without tissue carbonization. This depended on the length of the applicator and could measure more than 20 mm. To get large lesion volumes with short radiation times, but to avoid charring, in vivo graded powers were favorable. These were optimized for some systems. In the canine prostate, lesion diameters of up to 15 mm were achieved. For clinical use, interstitial applicators were inserted into the bulky BPH transurethrally through a cystoscope under direct vision, either directly or aided by an introducer system. The number of fiber placements depended on the size and configuration of the gland and varied between 3 and 16. With the 980 nm diode laser and an applicator with conical beam pattern, irradiation was performed for 3 minutes per fiber placement using stepwise reduced power (20 W for 30 s, 15 W for 30 s, 10 W for 30 s and 7 W for 90 s). With the 830 nm diode laser and diffusor tip, the initial power of 10 W was reduced to 5 W within 4 minutes total radiation time. From 1993, 19 patients were treated with diode lasers (830 and 980 nm). Three months follow-up in 15 patients treated with 830 nm showed an AUA-score change from 18.9 to 5.9 and a peak flow rate change from 7.8 to 15.2 ml/s.

  11. Boosting the coagulation restores haemostasis in ticagrelor-treated mice.

    PubMed

    Pehrsson, Susanne; Hansson, Kenny; Nelander, Karin; Nylander, Sven

    2016-12-01

    Antiplatelet therapy is given to patients with acute coronary syndrome to reduce the risk for thrombotic events, but may increase the risk for bleeding. Ticagrelor was administered intravenously to mice. Cumulative blood loss and bleeding time were measured after cutting 5 mm of the tail, 20 min after the start of ticagrelor infusion. The tail was placed in a hemoglobin-sensitive device measuring light absorbance (abs) over time for 35 min. Activated recombinant human factor VII (rhFVIIa; NovoSeven; NovoNordisk A/S, Bagsvaerd, Denmark) 1 mg/kg (study 1); recombinant human prothrombin (rhFII, MEDI8111) 10 mg/kg (study 2); or vehicle was given intravenously once bleeding had commenced, within 90s after tail cut. Ticagrelor resulted in more than 98% inhibition of ex-vivo ADP-induced platelet aggregation. In study 1, the median blood loss in the ticagrelor, vehicle, and rhFVIIa groups were 909, 122, and 397 abs*s, respectively (P < 0.05 for both comparisons, including the ticagrelor group). Similar pattern was seen for bleeding time. The median bleeding time in the ticagrelor, vehicle, and rhFVIIa groups were 2003, 449, and 884s, respectively (P < 0.05 for both comparisons, including the ticagrelor group). In study 2, the median blood loss and bleeding time in the ticagrelor group were 362 abs*s and 1847s. The corresponding numbers for the vehicle and rhFII groups were 71 abs*s and 613s, and 178 abs*s and 701s, respectively (P < 0.05 for comparisons between ticagrelor and vehicle for both blood loss and bleeding time). In mice dosed to complete P2Y12 inhibition, boosting coagulation by administration of rhFVIIa or rhFII within 90s after bleeding initiation can partly reverse ticagrelor-enhanced bleeding.

  12. Pre-analytical effects of pneumatic tube system transport on routine haematology and coagulation tests, global coagulation assays and platelet function assays.

    PubMed

    Le Quellec, Sandra; Paris, Mickaël; Nougier, Christophe; Sobas, Frédéric; Rugeri, Lucia; Girard, Sandrine; Bordet, Jean-Claude; Négrier, Claude; Dargaud, Yesim

    2017-05-01

    Pneumatic tube system (PTS) in hospitals is commonly used for the transport of blood samples to clinical laboratories, as it is rapid and cost-effective. The aim was to compare the effects on haematology samples of a newly acquired ~2km-long PTS that links 2 hospitals with usual transport (non-pneumatic tube system, NPTS). Complete blood cell count, routine coagulation assays, platelet function tests (PFT) with light-transmission aggregometry and global coagulation assays including ROTEM® and thrombin generation assay (TGA) were performed on blood samples from 30 healthy volunteers and 9 healthy volunteers who agreed to take aspirin prior to blood sampling. The turnaround time was reduced by 31% (p<0.001) with the use of PTS. No statistically significant difference was observed for most routine haematology assays including PFT, and ROTEM® analysis. A statistically significant, but not clinically relevant, shortening of the APTT after sample transport by PTS was found (mean±SD: 30s±1.8 vs. 29.5s±2.1 for NPTS). D-dimer levels were 7.4% higher after transport through PTS but were not discordant. A statistically significant increase of thrombin generation was found in both platelet poor- and platelet rich- plasma samples after PTS transport compared to NPTS transport. PTS is suitable for the transport of samples prior to routine haematology assays including PFT, but should not be used for samples intended for thrombin generation measurement. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Electrosurgical device for both mechanical cutting and coagulation of bleeding

    DOEpatents

    Doss, J.D.; McCabe, C.W.

    1985-02-08

    Bipolar electrical coagulation of tissue using radiofrequency energy is combined with the functions of conventional surgical pressure tissue cutting instruments without significant modification thereof in a single instrument with the result that a surgeon can perform both procedures without having to redirect his attention from the area of the surgery. 4 figs.

  14. Electrosurgical device for both mechanical cutting and coagulation of bleeding

    DOEpatents

    Doss, James D.; McCabe, Charles W.

    1987-01-01

    Bipolar electrical coagulation of tissue using radio-frequency energy is combined with the functions of conventional surgical pressure tissue cutting instruments without significant modification thereof in a single instrument with the result that a surgeon can perform both procedures without having to redirect his attention from the area of the surgery.

  15. The coagulation rate of charged aerosols in ionized gases

    SciTech Connect

    Matsoukas, T.

    1997-03-15

    The charging of aerosols occurs by natural or artificial means in many systems, for example, in electrostatic precipitators and radioactive ionizers, in flames and glow discharges, in ambient air, and in outer space. The author obtains analytical expressions for the coagulation rate of aerosols in ionized gases taking into account the statistical distribution of the aerosol charge due to the random nature the charging process. Depending on the asymmetry of the ionic environment, the charge distribution may be bipolar (symmetric charging) or unipolar (highly asymmetric charging). In symmetric charging the attraction between opposite charges is almost exactly counterbalanced by repulsion between like charges and the net effect is a slight increase in the overall coagulation rate. In asymmetric charging all particles carry charges of the same polarity, interparticle interactions are repulsive, and the rate of coagulation decreases. However, the effect of the charge distribution in these systems is to increase the rate of coagulation above the rate that would be obtained if all particles carried the mean charge. This increase is substantial for larger particles in highly asymmetric ionic environments.

  16. The Inflammatory Actions of Coagulant and Fibrinolytic Proteases in Disease

    PubMed Central

    Schuliga, Michael

    2015-01-01

    Aside from their role in hemostasis, coagulant and fibrinolytic proteases are important mediators of inflammation in diseases such as asthma, atherosclerosis, rheumatoid arthritis, and cancer. The blood circulating zymogens of these proteases enter damaged tissue as a consequence of vascular leak or rupture to become activated and contribute to extravascular coagulation or fibrinolysis. The coagulants, factor Xa (FXa), factor VIIa (FVIIa), tissue factor, and thrombin, also evoke cell-mediated actions on structural cells (e.g., fibroblasts and smooth muscle cells) or inflammatory cells (e.g., macrophages) via the proteolytic activation of protease-activated receptors (PARs). Plasmin, the principle enzymatic mediator of fibrinolysis, also forms toll-like receptor-4 (TLR-4) activating fibrin degradation products (FDPs) and can release latent-matrix bound growth factors such as transforming growth factor-β (TGF-β). Furthermore, the proteases that convert plasminogen into plasmin (e.g., urokinase plasminogen activator) evoke plasmin-independent proinflammatory actions involving coreceptor activation. Selectively targeting the receptor-mediated actions of hemostatic proteases is a strategy that may be used to treat inflammatory disease without the bleeding complications of conventional anticoagulant therapies. The mechanisms by which proteases of the coagulant and fibrinolytic systems contribute to extravascular inflammation in disease will be considered in this review. PMID:25878399

  17. Application performance of a new coagulant in wastewater reuse.

    PubMed

    Fu, Ying; Wang, Jingzhi; Wang, Yanzheng; Lu, Ningning

    2016-01-01

    Ultraviolet (UV) absorption characteristics of poly-Al-Zn-Fe (PAZF), a polymerized coagulant containing three kinds of metallic elements prepared from a galvanized-aluminum slag, was analyzed by UV-visible spectrophotometry during its polymerization process. Pollutant removal by PAZF in treating various wastewaters was investigated, in comparison with that of polyaluminum chloride (PAC). The results showed that PAZF can be applied to different wastewaters and had excellent coagulation behavior due to its special internal composition. Various complicated substances having different absorption wavelengths and polymeric properties were produced during the PAZF polymerization process, and the structures of these complicated substances were adjusted continuously with the increasing of the polymerization time. PAZF posed better turbidity and organic matter (chemical oxygen demand, COD(Cr)) removal than PAC for different wastewaters, and the required dosage of PAZF was far lower than that of PAC when achieving the same coagulation performance. For pharmaceutical, sugar, dyeing, simulated pesticide and landscape wastewaters, PAZF gave higher removal of turbidity or COD(Cr) than PAC, by up to 79.5% (coagulant dose: 74 mg/L) or 16% (148 mg/L), 13.4% (111 mg/L) or 10% (185 mg/L), 26.5% (148 mg/L) or 8.1% (18.5 mg/L), 40% (18.5 mg/L) or 13.4% (111 mg/L), and 5% (70 mg/L) or 5% (70 mg/L), respectively.

  18. [Breakage and regrowth of flocs coagulation with polyaluminum chloride (PACl)].

    PubMed

    Zhang, Zhong-Guo; Luan, Zhao-Kun; Zhao, Ying; Cui, Jian-Hua; Chen, Zhao-Yang; Li, Yan-Zhong

    2007-02-01

    The conventional jar test and the monitoring technique of floc size in line were employed to investigate the breakage and regrowth of the flocs formed by PACl. It was found that the breakage and regrowth of flocs varied with coagulation zones. The flocs formed in stabilization zone were of high strength and difficult to break, and could regrow better after broken, with the recovery factor of up to 259%. The flocs formed in charge neutralization zone were of the lowest strength and prone to break, but could reform completely after broken. The flocs formed in restabilization and sweep coagulation zones were also of high strength and difficult to break, but significantly irreversible after broken. The recovery factor of the broken flocs in sweep coagulation zone was only 18.6%. The effects of remixing on the breakage and regrowth of flocs increased with remixing intensity. In sweep coagulation zone, the settling height and mean settling velocity of the interface between flocs blanket and water were lower for the broken and partly reforming flocs than for those unbroken; Moreover, in flocculation settling and zone settling zones, the instantaneous settling velocity of the interface at the same flocs concentration was also lower for the broken flocs than for those unbroken, but in compression settling zone, the instantaneous settling velocity was the same whether the flocs were broken or not.

  19. Mathematical models of blood coagulation and platelet adhesion: clinical applications.

    PubMed

    Panteleev, M A; Ananyeva, N M; Ataullakhanov, F I; Saenko, E L

    2007-01-01

    At present, computer-assisted molecular modeling and virtual screening have become effective and widely-used tools for drug design. However, a prerequisite for design and synthesis of a therapeutic agent is determination of a correct target in the metabolic system, which should be either inhibited or stimulated. Solution of this extremely complicated problem can also be assisted by computational methods. This review discusses the use of mathematical models of blood coagulation and platelet-mediated primary hemostasis and thrombosis as cost-effective and time-saving tools in research, clinical practice, and development of new therapeutic agents and biomaterials. We focus on four aspects of their application: 1) efficient diagnostics, i.e. theoretical interpretation of diagnostic data, including sensitivity of various clotting assays to the changes in the coagulation system; 2) elucidation of mechanisms of coagulation disorders (e.g. hemophilias and thrombophilias); 3) exploration of mechanisms of action of therapeutic agents (e.g. recombinant activated factor VII) and planning rational therapeutic strategy; 4) development of biomaterials with non-thrombogenic properties in the design of artificial organs and implantable devices. Accumulation of experimental knowledge about the blood coagulation system and about platelets, combined with impressive increase of computational power, promises rapid development of this field.

  20. A plasma proteolysis pathway comprising blood coagulation proteases.

    PubMed

    Yang, Lu; Li, Yun; Bhattacharya, Arup; Zhang, Yuesheng

    2016-07-05

    Coagulation factors are essential for hemostasis. Here, we show that these factors also team up to degrade plasma proteins that are unrelated to hemostasis. Prolidase, SRC and amyloid β1-42 (Aβ1-42) are used as probes. Each probe, upon entering the blood circulation, binds and activates factor XII (FXII), triggering the intrinsic and common coagulation cascades, which in turn activate factor VII, a component of the extrinsic coagulation cascade. Activated factor VII (FVIIa) rapidly degrades the circulating probes. Therefore, FXII and FVIIa serve as the sensor/initiator and executioner, respectively, for the proteolysis pathway. Moreover, activation of this pathway by one probe leads to the degradation of all three probes. Significant activation of this pathway follows tissue injury and may also occur in other disorders, e.g., Alzheimer's disease, of which Aβ1-42 is a key driver. However, enoxaparin, a clinically used anticoagulant, inhibits the proteolysis pathway and elevates plasma levels of the probes. Enoxaparin may also mitigate potential impact of activators of the proteolysis pathway on coagulation. Our results suggest that the proteolysis pathway is important for maintaining low levels of various plasma proteins. Our finding that enoxaparin inhibits this pathway provides a means to control it. Inhibition of this pathway may facilitate the development of disease biomarkers and protein therapeutics, e.g., plasma Aβ1-42 as a biomarker of Alzheimer's disease or recombinant human prolidase as an antitumor agent.

  1. Defective thrombus formation in mice lacking coagulation factor XII

    PubMed Central

    Renné, Thomas; Pozgajová, Miroslava; Grüner, Sabine; Schuh, Kai; Pauer, Hans-Ulrich; Burfeind, Peter; Gailani, David; Nieswandt, Bernhard

    2005-01-01

    Blood coagulation is thought to be initiated by plasma protease factor VIIa in complex with the membrane protein tissue factor. In contrast, coagulation factor XII (FXII)–mediated fibrin formation is not believed to play an important role for coagulation in vivo. We used FXII-deficient mice to study the contributions of FXII to thrombus formation in vivo. Intravital fluorescence microscopy and blood flow measurements in three distinct arterial beds revealed a severe defect in the formation and stabilization of platelet-rich occlusive thrombi. Although FXII-deficient mice do not experience spontaneous or excessive injury-related bleeding, they are protected against collagen- and epinephrine-induced thromboembolism. Infusion of human FXII into FXII-null mice restored injury-induced thrombus formation. These unexpected findings change the long-standing concept that the FXII-induced intrinsic coagulation pathway is not important for clotting in vivo. The results establish FXII as essential for thrombus formation, and identify FXII as a novel target for antithrombotic therapy. PMID:16009717

  2. Acoustic determination of early stages of intravascular blood coagulation.

    PubMed

    Uzlova, Svetlana G; Guria, Konstantin G; Guria, Georgy Th

    2008-10-13

    The blood coagulation system (BCS) is a complex biological system playing a principal role in the maintenance of haemostasis. Insufficient activity of the BCS may lead to bleeding and blood loss (e.g. in the case of haemophilia). On the other hand, excessive activity may cause intravascular blood coagulation, thromboses and embolization. Most of the methods currently used for BCS monitoring suffer from the major disadvantage of being invasive. The purpose of the present work is to demonstrate the feasibility of using ultrasonic methods for non-invasive registration of the early stages of blood coagulation processes in intensive flows. With this purpose, a special experimental set-up was designed, facilitating the simultaneous detection of optical and acoustic signals during the clotting process. It was shown that (i) as microemboli appear in the flow during the early stage of blood coagulation, the intensity of the Doppler signal increases twofold, and (ii) microemboli formation in the early stages of blood clotting always reveals itself through an acoustic contrast. Both of these effects are well defined, so we hope that they may be used for non-invasive BCS monitoring in clinical practice.

  3. Removal and Transformation of Estrogens During the Coagulation Process

    EPA Science Inventory

    Estrogenic compounds have been shown to be present in surface waters, leading to concerns over the possible presence of endocrine disrupting compounds in finished drinking waters. Bench-scale studies (jar tests) simulating coagulation were conducted to evaluate the ability of tw...

  4. Treatment of melanoidin wastewater by anaerobic digestion and coagulation.

    PubMed

    Arimi, Milton M; Zhang, Yongjun; Götz, Gesine; Geißen, Sven-Uwe

    2015-01-01

    Melanoidins are dark-coloured recalcitrant pollutants found in many industrial wastewaters including coffee-manufacturing effluent, molasses distillery wastewater (MDWW) and other wastewater with molasses as the raw material. The wastewaters are mostly treated with anaerobic digestion after some dilution to minimize the inhibition effect. However, the dark colour and recalcitrant dissolved organic carbon (DOC) mainly caused by melanoidin are not effectively removed. The aim of this study was to investigate the removal of colour and remnant DOC by different coagulants from anaerobically digested MDWW. From the six coagulants tested, ferric chloride had the highest melanoidin (48%), colour (92.7%) and DOC (63.3%) removal at pH 5 and a dosage of 1.6 g/l. Both polymer and inorganic salt coagulants tested had optimal colour, melanoidin and DOC removal at acidic pH. The molecular size distribution of synthetic melanoidins by liquid chromatography-organic carbon detection indicated a preferential removal of high-molecular-weight melanoidins over low weight melanoidins by the coagulation. Further studies should focus on how to improve biodegradability of the treated effluent for it to be reused as dilution water for anaerobic digestion.

  5. Dust Coagulation in Infalling Protostellar Envelopes I. Compact Grains

    NASA Technical Reports Server (NTRS)

    Yorke, H.; Suttner, G.; Lin, D.

    1999-01-01

    Dust plays a key role in the optical, thermodynamic and gas dynamical behavior of collapsing molecular cores. Because of relative velocities of the individual dust grains, coagulation and shattering can modify the grain size distribution and due to corresponding changes in the medium's opacity significantly influence the evolution during early phase of star formation.

  6. Dust Coagulation in Infalling Protostellar Envelopes I. Compact Grains

    NASA Technical Reports Server (NTRS)

    Yorke, H.; Lin, D.; Suttner, G.

    1999-01-01

    Dust plays a key role in the optical, thermodynamic and gas dynamical behavior of collapsing molecular cores. Because of relative velocities of the individual dust grains, coagulation and shattering can modify the grain size distribution and -- due to corresponding changes in the medium's opacity significantly -- influence the evolution during early phases of star formation.

  7. Extracellular RNA constitutes a natural procoagulant cofactor in blood coagulation

    PubMed Central

    Kannemeier, Christian; Shibamiya, Aya; Nakazawa, Fumie; Trusheim, Heidi; Ruppert, Clemens; Markart, Philipp; Song, Yutong; Tzima, Eleni; Kennerknecht, Elisabeth; Niepmann, Michael; von Bruehl, Marie-Luise; Sedding, Daniel; Massberg, Steffen; Günther, Andreas; Engelmann, Bernd; Preissner, Klaus T.

    2007-01-01

    Upon vascular injury, locally controlled haemostasis prevents life-threatening blood loss and ensures wound healing. Intracellular material derived from damaged cells at these sites will become exposed to blood components and could contribute to blood coagulation and pathological thrombus formation. So far, the functional and mechanistic consequences of this concept are not understood. Here, we present in vivo and in vitro evidence that different forms of eukaryotic and prokaryotic RNA serve as promoters of blood coagulation. Extracellular RNA was found to augment (auto-)activation of proteases of the contact phase pathway of blood coagulation such as factors XII and XI, both exhibiting strong RNA binding. Moreover, administration of exogenous RNA provoked a significant procoagulant response in rabbits. In mice that underwent an arterial thrombosis model, extracellular RNA was found associated with fibrin-rich thrombi, and pretreatment with RNase (but not DNase) significantly delayed occlusive thrombus formation. Thus, extracellular RNA derived from damaged or necrotic cells particularly under pathological conditions or severe tissue damage represents the long sought natural “foreign surface” and provides a procoagulant cofactor template for the factors XII/XI-induced contact activation/amplification of blood coagulation. Extracellular RNA thereby reveals a yet unrecognized target for antithrombotic intervention, using RNase or related therapeutic strategies. PMID:17405864

  8. Blood coagulation using High Intensity Focused Ultrasound (HIFU)

    NASA Astrophysics Data System (ADS)

    Nguyen, Phuc V.; Oh, Junghwan; Kang, Hyun Wook

    2014-03-01

    High Intensity Focused Ultrasound (HIFU) technology provides a feasible method of achieving thermal coagulation during surgical procedures. One of the potential clinical benefits of HIFU can induce immediate hemostasis without suturing. The objective of this study was to investigate the efficiency of a HIFU system for blood coagulation on severe vascular injury. ngHIFU treatment was implemented immediately after bleeding in artery. The ultrasound probe was made of piezoelectric material, generating a central frequency of 2.0 MHz as well as an ellipsoidal focal spot of 2 mm in lateral dimension and 10 mm in axial dimension. Acoustic coagulation was employed on a perfused chicken artery model in vitro. A surgical incision (1 to 2 mm long) was made with a scapel on the arterial wall, and heparinized autologous blood was made to leak out from the incision with a syringe pump. A total of 5 femoral artery incisions was treated with the HIFU beam. The intensity of 4500 W/cm2 at the focus was applied for all treatments. Complete hemostasis was achieved in all treatments, along with the treatment times of 25 to 50 seconds. The estimated intraoperative blood loss was from 2 to 5 mL. The proposed HIFU system may provide an effective method for immediate blood coagulation for arteries and veins in clinical applications.

  9. Regulation of tissue factor coagulant activity on cell surfaces

    PubMed Central

    RAO, L.V.M.; PENDURTHI, U.R.

    2012-01-01

    Summary Tissue factor (TF) is a transmembrane glycoprotein and an essential component of factor VIIa-TF enzymatic complex that triggers activation of the coagulation cascade. Formation of TF-FVIIa complexes on cell surfaces not only trigger the coagulation cascade but also transduce cell signaling via activation of protease-activated receptors. Tissue factor is expressed constitutively on cell surfaces of a variety of extravascular cell types, including fibroblasts and pericytes in and surrounding blood vessel walls and epithelial cells but generally absent on cells that come in contact with blood directly. However, TF expression could be induced in some blood cells, such as monocytes and endothelial cells, following an injury or pathological stimuli. Tissue factor is essential for hemostasis, but aberrant expression of TF leads to thrombosis. Therefore, a proper regulation of TF activity is critical for the maintenance of hemostatic balance and health in general. TF-FVIIa coagulant activity at the cell surface is influenced not only by TF protein expression levels but also independently by a variety of mechanisms, including alterations in membrane phospholipid composition and cholesterol content, thiol-dependent modifications of TF allosteric disulfide bond, and other post-translational modifications of TF. In this article, we critically review key literature on mechanisms by which TF coagulant activity is regulated at the cell surface in the absence of changes in TF protein levels with specific emphasis on recently published data and provide the authors’ perspective on the subject. PMID:23006890

  10. Nanofiltration based water reclamation from tannery effluent following coagulation pretreatment.

    PubMed

    Dasgupta, J; Mondal, D; Chakraborty, S; Sikder, J; Curcio, S; Arafat, H A

    2015-11-01

    Coagulation-nanofiltration based integrated treatment scheme was employed in the present study to maximize the removal of toxic Cr(VI) species from tannery effluents. The coagulation pretreatment step using aluminium sulphate hexadecahydrate (alum) was optimized by response surface methodology (RSM). A nanofiltration unit was integrated with this coagulation pre-treatment unit and the resulting flux decline and permeate quality were investigated. Herein, the coagulation was conducted under response surface-optimized operating conditions. The hybrid process demonstrated high chromium(VI) removal efficiency over 98%. Besides, fouling of two of the tested nanofiltration membranes (NF1 and NF3) was relatively mitigated after feed pretreatment. Nanofiltration permeation fluxes as high as 80-100L/m(2)h were thereby obtained. The resulting permeate stream quality post nanofiltration (NF3) was found to be suitable for effective reuse in tanneries, keeping the Cr(VI) concentration (0.13mg/L), Biochemical Oxygen Demand (BOD) (65mg/L), Chemical Oxygen Demand (COD) (142mg/L), Total Dissolved Solids (TDS) (108mg/L), Total Solids (TS) (86mg/L) and conductivity levels (14mho/cm) in perspective. The process water reclaiming ability of nanofiltration was thereby substantiated and the effectiveness of the proposed hybrid system was thus affirmed.

  11. Membrane coagulation bioreactor (MCBR) for drinking water treatment.

    PubMed

    Tian, Jia-Yu; Liang, Heng; Li, Xing; You, Shi-jie; Tian, Sen; Li, Gui-bai

    2008-08-01

    In this paper, a novel submerged ultrafiltration (UF) membrane coagulation bioreactor (MCBR) process was evaluated for drinking water treatment at a hydraulic retention time (HRT) as short as 0.5h. The MCBR performed well not only in the elimination of particulates and microorganisms, but also in almost complete nitrification and phosphate removal. As compared to membrane bioreactor (MBR), MCBR achieved much higher removal efficiencies of organic matter in terms of total organic carbon (TOC), permanganate index (COD(Mn)), dissolved organic carbon (DOC) and UV absorbance at 254nm (UV(254)), as well as corresponding trihalomethanes formation potential (THMFP) and haloacetic acids formation potential (HAAFP), due to polyaluminium chloride (PACl) coagulation in the bioreactor. However, the reduction of biodegradable dissolved organic carbon (BDOC) and assimilable organic carbon (AOC) by MCBR was only 8.2% and 10.1% higher than that by MBR, indicating that biodegradable organic matter (BOM) was mainly removed through biodegradation. On the other hand, the trans-membrane pressure (TMP) of MCBR developed much lower than that of MBR, which implies that coagulation in the bioreactor could mitigate membrane fouling. It was also identified that the removal of organic matter was accomplished through the combination of three unit effects: rejection by UF, biodegradation by microorganism and coagulation by PACl. During filtration operation, a fouling layer was formed on the membranes surface of both MCBR and MBR, which functioned as a second membrane for further separating organic matter.

  12. Action of Nanoparticles on Platelet Activation and Plasmatic Coagulation

    PubMed Central

    Fröhlich, Eleonore

    2016-01-01

    Nanomaterials can get into the blood circulation after injection or by release from implants but also by permeation of the epithelium after oral, respiratory or dermal exposure. Once in the blood, they can affect hemostasis, which is usually not intended. This review addresses effects of biological particles and engineered nanomaterials on hemostasis. The role of platelets and coagulation in normal clotting and the interaction with the immune system are described. Methods to identify effects of nanomaterials on clotting and results from in vitro and in vivo studies are summarized and the role of particle size and surface properties discussed. The literature overview showed that mainly pro-coagulative effects of nanomaterials have been described. In vitro studies suggested stronger effects of smaller than of larger NPs on coagulation and a greater importance of material than of surface charge. For instance, carbon nanotubes, polystyrene particles, and dendrimers inferred with clotting independent from their surface charge. Coating of particles with polyethylene glycol was able to prevent interaction with clotting by some particles, while it had no effect on others and the more recently developed bio-inspired surfaces might help to design coatings for more biocompatible particles. The mainly pro-coagulative action of nanoparticles could present a particular risk for individuals affected by common diseases such as diabetes, cancer, and cardiovascular diseases. Under standardized conditions, in vitro assays using human blood appear to be a suitable tool to study mechanisms of interference with hemostasis and to optimize hemocompatibility of nanomaterials. PMID:26063498

  13. Synthetic polyphosphate inhibits endogenous coagulation and platelet aggregation in vitro

    PubMed Central

    Yang, Xiaoyang; Wan, Mengjie; Liang, Ting; Peng, Minyuan; Chen, Fangping

    2017-01-01

    Platelet-derived polyphosphate has previously been indicated to induce coagulation. However, industrially synthesized polyphosphate has been found to have different effects from those of the platelet-derived form. The present study investigated whether synthetic sodium polyphosphate inhibits coagulation using routine coagulation tests and thromboelastography. Synthetic polyphosphate was found to inhibit adenosine diphosphate-, epinephrine-, arachidonic acid-, ristocetin-, thrombin-, oxytocin- and pituitrin-induced platelet aggregation. The effects of synthetic polyphosphate in clotting inhibition were revealed by the analysis of clotting factor activity and platelet aggregation tests. Synthetic polyphosphate may inhibit platelet aggregation by reducing platelet calcium levels, as indicated by the results of flow cytometric analysis and high-throughput fluorescent screening. Furthermore, analysis of thromboxane (TX)B2 by ELISA indicated that synthetic polyphosphate reduces platelet aggregation by inhibiting the TXA2 signaling pathway. In conclusion, synthetic polyphosphate inhibits clotting factor activity and endogenous coagulation by reducing the levels of calcium ions and TXA2 to curb platelet aggregation. PMID:28123708

  14. Removal and Transformation of Estrogens During the Coagulation Process

    EPA Science Inventory

    Estrogenic compounds have been shown to be present in surface waters, leading to concerns over the possible presence of endocrine disrupting compounds in finished drinking waters. Bench-scale studies (jar tests) simulating coagulation were conducted to evaluate the ability of tw...

  15. Non-Equilibrium Iron Clusters Coagulation and Thermal Decomposition at High Temperatures

    NASA Astrophysics Data System (ADS)

    Starikovskii, A. Yu.; Zaslonko, I. S.

    The fast thermal decomposition of Fe(CO)5 (1000-8000 ppm) behind reflected shock waves was used as source of iron atoms. The growth and decomposition of iron clusters was observed using light absorption technique at λ = 632.8 nm. The iron cluster formation was studied behind incident shock waves (T = 1200 — 2000 K, p = 5 — 50 bar) and cluster decomposition behind reflected shock waves (T = 2600 — 3000 K, p = 10 — 100 bar). The temperature and pressure dependencies of observable rate constants for iron cluster growth and thermal decomposition has been obtained. The experimental data were treated using master equation solution for the cluster size distribution function. The light absorption in the system is shown to depend on the total atoms amount in the clusters with n* < n < n **, were n* ~ 3 — 5, n** ~ 104. When coagulation time is rather small that the concentration of clusters with n > n** is negligible and concentration of small clusters (n < n*) permanently decreases, light absorption increase. After that number of atoms enclosed into the clusters with n* < n < n** became decreasing and the total light-absorption cross section decreases. So, observations of the absorption gives us an important information about streams through the particle size axes, and observable rate constant kobs = dln(D)/dt is a good parameter for the description of the kinetic behavior at the broad variations of temperature and pressure for an iron cluster ensemble.

  16. Bili lights

    MedlinePlus

    Phototherapy for jaundice; Bilirubin - bili lights; Neonatal care - bili lights; Newborn care - bili lights ... Phototherapy involves shining fluorescent light from the bili lights on bare skin. A specific wavelength of light can break down bilirubin into a form that ...

  17. Blood coagulation and the risk of atherothrombosis: a complex relationship.

    PubMed

    Spronk, Henri Mh; van der Voort, Danielle; Ten Cate, Hugo

    2004-12-01

    The principles of Virchov's triad appear to be operational in atherothrombosis or arterial thrombosis: local flow changes and particularly vacular wall damage are the main pathophysiological elements. Furthermore, alterations in arterial blood composition are also involved although the specific role and importance of blood coagulation is an ongoing matter of debate. In this review we provide support for the hypothesis that activated blood coagulation is an essential determinant of the risk of atherothrombotic complications. We distinguish two phases in atherosclerosis: In the first phase, atherosclerosis develops under influence of "classical" risk factors, i.e. both genetic and acquired forces. While fibrinogen/fibrin molecules participate in early plaque lesions, increased activity of systemic coagulation is of no major influence on the risk of arterial thrombosis, except in rare cases where a number of specific procoagulant forces collide. Despite the presence of tissue factor - factor VII complex it is unlikely that all fibrin in the atherosclerotic plaque is the direct result from local clotting activity. The dominant effect of coagulation in this phase is anticoagulant, i.e. thrombin enhances protein C activation through its binding to endothelial thrombomodulin.The second phase is characterized by advancing atherosclerosis, with greater impact of inflammation as indicated by an elevated level of plasma C-reactive protein, the result of increased production influenced by interleukin-6. Inflammation overwhelms protective anticoagulant forces, which in itself may have become less efficient due to down regulation of thrombomodulin and endothelial cell protein C receptor (EPCR) expression. In this phase, the inflammatory drive leads to recurrent induction of tissue factor and assembly of catalytic complexes on aggregated cells and on microparticles, maintaining a certain level of thrombin production and fibrin formation. In advanced atherosclerosis systemic and

  18. Clinical and prognostic significance of coagulation assays in lung cancer.

    PubMed

    Tas, Faruk; Kilic, Leyla; Serilmez, Murat; Keskin, Serkan; Sen, Fatma; Duranyildiz, Derya

    2013-03-01

    Activation of coagulation and fibrinolysis is frequently encountered among cancer patients. Such tumors are supposed to be associated with higher risk of invasion, metastases and eventually worse outcome. The aim of this study is to explore the prognostic value of blood coagulation tests for lung cancer patients. The study comprised 110 lung cancer patients. Pretreatment blood coagulation tests including PT, aPTT, PTA, INR, D-dimer, fibrinogen levels and platelet counts were evaluated. The plasma level of all coagulation tests revealed statistically significant difference between patient and control group (p < 0.001). There was a significant association between D-Dimer levels and histological subtypes of NSCLC, pointing an elevated plasma D-dimer level in squamous cell cancer (p = 0.035). Patients with extensive stage SCLC exhibited evidently higher levels of D-Dimer, INR and PLT (p = 0.037, p = 0.042, p = 0.04, respectively). Prolongation of PT and INR had statistically significant adverse effect on survival (p = 0.05 and p = 0.014, respectively). Although prolonged aPTT and high levels of D-dimer was associated with worse survival, the difference was not statistically significant (p = 0.117, p = 0.104). Multivariate analysis revealed INR as the sole independent prognostic variable among coagulation parameters (p = 0.05). In conclusion, elevation of PT and INR are associated with decreased survival in lung cancer patients.

  19. Effects of ethanol intoxication and gender on blood coagulation.

    PubMed

    Spoerke, Nicholas; Underwood, Samantha; Differding, Jerome; Van, Phil; Sambasivan, Chitra; Shapiro, David; Schreiber, Martin

    2010-05-01

    Ethanol intoxication is a common contributor to traumatic injury. It is unknown whether ethanol consumption contributes to the coagulation differences seen between men and women after trauma. Our aim was to examine the combined effect of ethanol intoxication and gender on coagulation. Fifty-eight healthy subjects participated and chose to enter into a control group (CG; n = 20; 10 men and 10 women) or drinking group (DG; n = 38; 20 men and 18 women). Venous blood samples for thrombelastography, plasminogen activator inhibitor, thrombin-antithrombin complex, and tissue plasminogen activator were drawn at the beginning of the study. Subjects then interacted in a social atmosphere for at least 2 hours, eating and consuming alcoholic (DG) or nonalcoholic (CG) beverages. After 2 hours, blood alcohol level was determined and blood was drawn for a second set of coagulation studies. Demographics were similar between groups except for age (36.7 years CG vs. 29.9 years DG; p = 0.009). All baseline thrombelastography measurements were similar between the CG and DG. Blood alcohol levels in the DG were similar between genders at the end of study. At the end of study, a decreased rate of fibrin formation, decreased clot strength, and a decreased rate of fibrin cross-linking was seen in men but not in women. Fibrinolysis was inhibited in drinkers compared with controls. Consumption of commonly ingested quantities of alcohol correlated with the development of a hypocoagulable state in men but had no effect on coagulation status in women. This phenomenon may contribute to differences in post-trauma coagulation status previously noted between genders.

  20. Interstitial laser coagulation for localized destruction of solid tumors: overview of strategies

    NASA Astrophysics Data System (ADS)

    van Hillegersberg, Richard

    1997-06-01

    Interstitial laser coagulation (ILC) is a new method of producing localized tissue destruction, that may be used to eliminate soli tumors, such as liver metastases, pancreatic carcinomas, brain glioma and benign prostate hyperplasia. In ILC, Nd:YAG laser light is guided through flexible quartz fibers implanted directly into the tumor. Several experimental studies have shown the effectiveness of this therapy. Clinical application is feasible, however success in malignant tumors is limited by: (1) the restricted lesion size produced by a single optical fiber and (2) the lack of reliable on-line monitoring of the laser-induced effects. Research is therefore directed towards the development of multiple fiber application, guided by real time feedback of the laser-tissue interaction.

  1. Laser tissue welding: Effects of solder coagulation and tissue optical properties

    NASA Astrophysics Data System (ADS)

    Chan, Eric Kin

    Laser tissue welding can be a viable technique for repairing soft tissues in laparoscopic and endoscopic surgery. In recent years, the application of an albumin based solder has augmented laser welding of soft tissues. In order to develop a practical laparoscopic welding device, various factors affecting light dosimetry and solder coagulation must be carefully investigated. One important consideration for light dosimetry in laser welding is to obtain accurate tissue optical properties. Spectrophotometric Method using an integrating sphere is a widely accepted technique for determining tissue optical properties in vitro. However, this method requires a specimen large enough to fill the sample port of the integrating sphere. For small and delicate tissues, a technique was developed to estimate the optical properties of intact tissue using frozen ground tissues. This technique allows accurate approximation of tissue optical properties in the visible range. Lasers with wavelengths about the 2 μm water absorption peak are being considered for tissue welding. However, the absorption coefficient of water increases by a factor of two from 2.1 μm (Ho:YAG) to 2.01 μm (Tm:YAG). Soft tissue absorption properties about 2 μm were estimated from tissue thermal response created by a CW tunable laser recorded with an IR thermal camera. Tissue absorption properties are generally lower than those of water, but follow similar spectral profile of water. When the edges of an incision are approximated during laser welding, physical compression occurs which may affect tissue optical properties. The effects of compression on soft tissue optical properties were determined. For compression up to 2 kgf/cm2, soft tissue absorption and reduced scattering coefficients increase with compression in the visible and part of the IR range. A study has been conducted with scanning electron microscopy (SEM) to determine the photocoagulation process of an albumin based solder. The process involves

  2. Coagulation sensors based on magnetostrictive delay lines for biomedical and chemical engineering applications

    NASA Astrophysics Data System (ADS)

    Maliaritsi, E.; Zoumpoulakis, L.; Simitzis, J.; Vassiliou, P.; Hristoforou, E.

    2006-04-01

    Coagulation sensors based on the magnetostrictive delay line technique are presented in this paper. They are based on magnetostrictive ribbons and are used for measuring the coagulation, curing or solidification time of different liquids. Experimental results indicate that the presented sensing elements can determine the blood coagulation with remarkable repeatability, thus allowing their use as blood coagulation sensors. Additionally, results indicate that they can also measure curing time of resins, solidification of fluids and coagulation of chemical substances, therefore allowing their implementation in chemical engineering applications.

  3. Purification, characterization and application of dual coagulants containing chitosan and different Al species in coagulation and ultrafiltration process.

    PubMed

    Wang, Wenyu; Zhao, Shuang; Yue, Qinyan; Gao, Baoyu; Song, Wen; Feng, Lijuan

    2017-01-01

    The objective of this study was to investigate the effect of different Al species and chitosan (CS) dosages on coagulation performance, floc characteristics (floc sizes, strength and regrowth ability and fractal dimension) and membrane resistance in a coagulation-ultrafiltration hybrid process. Results showed that different Al species combined with humic acid in diverse ways. Ala had better removal efficiency, as determined by UV254 and dissolved organic carbon, which could be further improved by the addition of CS. In addition, the optimal dosage of different Al species was determined to be 4.0mg/L with the CS concentration of 1.0mg/L, by orthogonal coagulation experiments. Combining Ala/Alb/Alc with CS resulted in larger flocs, higher recovery, and higher fractal dimension values corresponding to denser flocs; in particular, the floc size at the steady state stage was four times larger than that obtained with Al species coagulants alone. The results of ultrafiltration experiments indicated that the external fouling percentage was significantly higher than that of internal fouling, at around 85% and 15%, respectively. In addition, the total membrane resistance was significantly decreased due to CS addition.

  4. Enhanced Coagulation-Flocculation Performance of Iron-Based Coagulants: Effects of PO43- and SiO32- Modifiers

    PubMed Central

    Teng, Houkai; Wang, Yili; Zhang, Yuxin; Zhao, Chuanliang; Liao, Yong

    2015-01-01

    PO43- and SiO32- are often used as modifier to improve stability and aggregating ability of the iron-base coagulants, however, there are few reports about their detailed comparison between the coagulation performance and mechanisms. In this study, three coagulants—polyferric phosphoric sulfate (PFPS), polysilicon ferric sulfate (PFSS), and polyferric sulfate (PFS) were synthesized; their structure and morphology were characterized by Fourier transformed infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and Scanning electron microscope (SEM). Alkali titration and Ferron species analysis were employed to investigate the hydrolysis performance and species distribution. Jar test was conducted to measure their coagulation behaviors at different dosage, pH, and temperatures in which the flocs properties were measured. The results showed that a number of new compounds were formed due to the presence of PO43- and SiO32-. Moreover, PFPS and PFSS had similar level in Fea as well as Feb. Among them, PFPS produced more multi-core iron atoms polymer and content of Feb, and the formed flocs were larger and denser. It exhibited superior coagulation performance in terms of turbidity reduction, UV254 removal and residual ferric concentration. Jar test and floc breakage/regrowth experiments indicated other than charge neutrality, the dominated mechanism involved in PFSS was the adsorption between polysilicic acid and solution particle, while PFPS was sweeping, entrapment/adsorption resulting from larger polymer colloid of Fe-P chemistry bond. PMID:26339902

  5. Characterization of a genetically engineered inactivation-resistant coagulation factor VIIIa

    PubMed Central

    Pipe, Steven W.; Kaufman, Randal J.

    1997-01-01

    Individuals with hemophilia A require frequent infusion of preparations of coagulation factor VIII. The activity of factor VIII (FVIII) as a cofactor for factor IXa in the coagulation cascade is limited by its instability after activation by thrombin. Activation of FVIII occurs through proteolytic cleavage and generates an unstable FVIII heterotrimer that is subject to rapid dissociation of its subunits. In addition, further proteolytic cleavage by thrombin, factor Xa, factor IXa, and activated protein C can lead to inactivation. We have engineered and characterized a FVIII protein, IR8, that has enhanced in vitro stability of FVIII activity due to resistance to subunit dissociation and proteolytic inactivation. FVIII was genetically engineered by deletion of residues 794-1689 so that the A2 domain is covalently attached to the light chain. Missense mutations at thrombin and activated protein C inactivation cleavage sites provided resistance to proteolysis, resulting in a single-chain protein that has maximal activity after a single cleavage after arginine-372. The specific activity of partially purified protein produced in transfected COS-1 monkey cells was 5-fold higher than wild-type (WT) FVIII. Whereas WT FVIII was inactivated by thrombin after 10 min in vitro, IR8 still retained 38% of peak activity after 4 hr. Whereas binding of IR8 to von Willebrand factor (vWF) was reduced 10-fold compared with WT FVIII, in the presence of an anti-light chain antibody, ESH8, binding of IR8 to vWF increased 5-fold. These results demonstrate that residues 1690–2332 of FVIII are sufficient to support high-affinity vWF binding. Whereas ESH8 inhibited WT factor VIII activity, IR8 retained its activity in the presence of ESH8. We propose that resistance to A2 subunit dissociation abrogates inhibition by the ESH8 antibody. The stable FVIIIa described here provides the opportunity to study the activated form of this critical coagulation factor and demonstrates that proteins can

  6. Plasmin-induced procoagulant effects in the blood coagulation: a crucial role of coagulation factors V and VIII.

    PubMed

    Ogiwara, Kenichi; Nogami, Keiji; Nishiya, Katsumi; Shima, Midori

    2010-09-01

    Plasminogen activators provide effective treatment for patients with acute myocardial infarction. However, paradoxical elevation of thrombin activity associated with failure of clot lysis and recurrent thrombosis has been reported. Generation of thrombin in these circumstances appears to be owing to plasmin (Plm)-induced activation of factor (F) XII. Plm catalyzes proteolysis of several coagulant factors, but the roles of these factors on Plm-mediated procoagulant activity remain to be determined. Recently developed global coagulation assays were used in this investigation. Rotational thromboelastometry using whole blood, clot waveform analysis and thrombin generation tests using plasma, showed that Plm (> or =125 nmol/l) shortened the clotting times in similar dose-dependent manners. In particular, the thrombin generation test, which was unaffected by products of fibrinolysis, revealed the enhanced coagulation with an approximately two-fold increase of peak level of thrombin generation. Studies using alpha2-antiplasmin-deficient plasma revealed that much lower dose of Plm (> or =16 nmol/l) actually contributed to enhancing thrombin generation. The shortening of clotting time could be observed even in the presence of corn trypsin inhibitor, supporting that Plm exerted the procoagulant activity independently of FXII. In addition, using specific coagulation-deficient plasmas, the clot waveform analysis showed that Plm did not shorten the clotting time in only FV-deficient or FVIII-deficient plasma in prothrombin time-based or activated partial thromboplastin time-based assay, respectively. Our results indicated that Plm did possess procoagulant activity in the blood coagulation, and this effect was likely attributed by multicoagulation factors, dependent on FV and/or FVIII.

  7. Effect of two-stage coagulant addition on coagulation-ultrafiltration process for treatment of humic-rich water.

    PubMed

    Liu, Ting; Chen, Zhong-lin; Yu, Wen-zheng; Shen, Ji-min; Gregory, John

    2011-08-01

    A novel two-stage coagulant addition strategy applied in a coagulation-ultrafiltration (UF) process for treatment of humic-rich water at neutral pH was investigated in this study. When aluminum sulfate (alum) doses were set at a ratio of 3:1 added during rapid mix stage and half way through flocculation stage, the integrated process of two-stage alum addition achieved almost the same organic matter removal as that of conventional one-stage alum addition at the same overall dose. Whereas membrane fouling could be effectively mitigated by the two-stage addition exhibited by trans-membrane pressure (TMP) developments. The TMP developments were found to be primarily attributed to external fouling on membrane surface, which was closely associated with floc characteristics. The results of jar tests indicated that the average size of flocs formed in two-stage addition mode roughly reached one half larger than that in one-stage addition mode, which implied a beneficial effect on membrane fouling reduction. Moreover, the flocs with more irregular structure and lower effective density resulted from the two-stage alum addition, which caused higher porosity of cake layer formed by such flocs on membrane surface. Microscopic observations of membrane surface demonstrated that internal fouling in membrane pores could be also remarkably limited by two-stage alum addition. It is likely that the freshly formed hydroxide precipitates were distinct in surface characteristics from the aged precipitates due to formation of more active groups or adsorption of more labile aluminum species. Consequently, the flocs could further connect and aggregate to contribute to preferable properties for filtration performance of the coagulation-UF process. As a simple and efficient approach, two-stage coagulant addition strategy could have great practical significance in coagulation-membrane processes.

  8. Mechanisms during suspended solids and phosphate concentration variations in wastewater coagulation process.

    PubMed

    Manamperuma, Lelum Duminda; Ratnaweera, Harsha Chandima; Martsul, A

    2016-10-01

    Coagulation-flocculation process is one of the most commonly used treatment process in water and wastewater treatment. Particles (PA) and phosphates (P) removal are the main objectives in wastewater coagulation. There is a general agreement on the dominant mechanism of PA and P removal during coagulation. While it is agreed that the PA and P removal reactions are competitive and takes place simultaneously, there is no clear understanding on the ratio of distribution of coagulants among the PA and P removal. The ratio can be significantly influenced by the content of PA and P, in addition to other water and coagulant quality factors. This paper attempts to provide a qualitative ratio of coagulant distribution based on PA:P proportion in raw water and OH:Al ratio in coagulants.

  9. New method for detection of blood coagulation using fiber-optic sensor

    NASA Astrophysics Data System (ADS)

    Fediay, Sergey G.; Kuznetzov, Alexsey V.

    1991-07-01

    The detection of blood coagulation is very important in therapeutics and surgery. It is necessary to determine the overall time taken for blood clotting, production rate of thrombin, presence or absence of blood coagulation factors, etc. In this paper a new method for detection of blood coagulation is presented. This method is based on the fiber-optic sensor and allows for the study of different ways of blood clotting (such as blood coagulation and platelets aggregation) separately, thus enhancing the precision of determination. The method for determining the blood coagulation presented possesses high precision in monitoring the process of coagulation. An elaborate mathematical model of the process of blood coagulation has been developed to help the computer handle obtained data.

  10. Effect of carryover of clot activators on coagulation tests during phlebotomy.

    PubMed

    Fukugawa, Yoko; Ohnishi, Hiroaki; Ishii, Takahiro; Tanouchi, Ayako; Sano, Junko; Miyawaki, Haruko; Kishino, Tomonori; Ohtsuka, Kouki; Yoshino, Hideaki; Watanabe, Takashi

    2012-06-01

    We investigated the effect of clot activators carried over from the serum tube on major coagulation tests during phlebotomy. First, blood specimens from 30 normal subjects were mixed with small amounts of fluid containing clot activators, and their effects on various coagulation tests were determined. Only the value of fibrin monomer complex displayed a remarkable change when thrombin-containing fluid was added to the blood specimens. Subsequently, 100 paired blood specimens (taken from 75 healthy volunteers and 25 patients taking warfarin) were collected in coagulation tubes before and after the serum tube using standard phlebotomy procedures. Various coagulation tests were performed to determine the effect of contamination of thrombin-containing blood on coagulation parameters. Differences between the 2 tubes were minimal but significant for some of the coagulation tests. Therefore, we conclude that the effect of clot activators in the serum tube on coagulation tests is minimal when standard phlebotomy procedures are used.

  11. Comparative assessment of water treatment using polymeric and inorganic coagulants

    NASA Astrophysics Data System (ADS)

    Manda, Innocent K. M.; Chidya, Russel C. G.; Saka, John D. K.; Biswick, Timothy T.

    2016-06-01

    Portable water plays a vital role in improving human life, particularly in controlling the spread of diseases. However, problems associated with lack of potable water are still common especially in developing countries including Malawi. Until now little information exists on the effectiveness of available commercial coagulants used by national water boards in Malawi. Therefore, this study was undertaken in Southern Region Water Board (SRWB) to investigate the efficiency of polymeric coagulants (sufdfloc 3850 and algaefloc 19s) in turbidity reduction comparative with inorganic coagulant (aluminium sulphate) at Zomba, Liwonde, Mangochi, Chikwawa and Mulanje Treatment plants. The jar test method was used to determine the effectiveness of the water coagulants. The results revealed that sudfloc 3850 was most effective in reducing turbidity at Mangochi (99.4 ± 0.06%) and Liwonde (97.2 ± 0.04%) using 0.4 mg L-1 flocculant dose. The Zomba, Mulanje and Chikwawa plants gave 19.56 ± 0.03%, 29.23 ± 0.02% and 9.43 ± 0.02% total reductions respectively. Algaefloc 19s afforded the highest turbidity reduction at Liwonde and Mangochi plants (98.66 ± 0.06 and 97.48 ± 0.05% at a dose of 0.4 and 0.6 mg L-1 respectively), while Chikwawa provided the lowest (9.52 ± 0.01%). At the Zomba and Mulanje plants 20.5 ± 0.03% and 28.4 ± 0.04% reductions were obtained respectively. The inorganic flocculant, alum provided a 99.0 ± 0.05% and 98.6 ± 0.04% reduction at a dose of 4.0 mg L-1 and 6.0 mg L-1 at Zomba and Liwonde plants respectively. The lowest reductions in turbidity were achieved at Chikwawa (7.50 ± 0.01%), Mangochi (12.97 ± 0.02%) and Mulanje (25.00 ± 0.02). The best and optimum pH ranges for polymeric and inorganic coagulants were 7.20-7.80 and 7.35 to 7.57 respectively. The results further revealed that sudfloc 3850 and algaefloc 19s achieved faster formation of heavy flocs than alum. At 0.4 mg L-1 flocculant dosage sudfloc 3850 and algaefloc 19s required ten times

  12. Clinical and prognostic significance of coagulation assays in melanoma.

    PubMed

    Tas, Faruk; Ciftci, Rumeysa; Kilic, Leyla; Bilgin, Elif; Keskin, Serkan; Sen, Fatma; Yildiz, Ibrahim; Yasasever, Vildan

    2012-10-01

    The activation of coagulation and fibrinolysis is frequently found among cancer patients. Such tumors are considered to be associated with a higher risk of invasion, metastases, and eventually worse outcome. The aim of this study is to explore the clinical and prognostic value of blood coagulation tests for melanoma patients. Pretreatment blood coagulation tests including prothrombin time (PT), activated partial thromboplastin time (APTT), prothrombin activity (PTA), international normalized ratio (INR), D-dimer (DD), fibrinogen (F) levels, and platelet (PLT) counts were carried out. This prospective study included 61 melanoma patients [stage I-II (n=10), stage III (n=14), stage IV (n=37), M1c (n=26) disease], and 50 healthy controls. It included 34 (56%) men, median age 53 years, range 16-88 years. Over half of the patients (54%) were in the metastatic stage and most of them (70%) had M1c. The plasma level of pretreatment blood coagulation tests including DD, F, APTT, INR levels, and PLT counts showed a statistically significant difference between the patient and the control group (P<0.001 for all, but P=0.049 for INR). The levels of INR, DD, F, and PLT counts were higher and APTT was lower in the melanoma group, whereas the PT and PTA levels did not show any significant difference. There was a significant association between PT, PTA, INR, and PLT levels and the age of the patient. Patients with node metastasis in M0 disease had higher levels of PTA and PLT counts (P=0.002 and 0.048, respectively) and lower levels of PT and INR (P=0.056 and 0.046, respectively). The M1c patients tended to have higher plasma F levels (437 vs. 297 mg/dl, P=0.055) than M1a and M1b patients. The 1-year survival rate for all patients was 70%. In association with distant metastasis, advanced metastatic stage (M1c), elevated lactate dehydrogenase, and erythrocyte sedimentation rate, only elevated plasma F levels had a significantly adverse effect on survival among the coagulation

  13. Peculiarities of coagulation action of IR lasers (1-3 um) radiation on cornea

    NASA Astrophysics Data System (ADS)

    Berezin, Yuri D.; Boiko, Ernest V.; Volkov, Venjamin V.; Danilichev, Vladimir F.; Ganin, Dmitry V.; Gatzu, Andrey F.; Smirnov, Nicolay N.; Lazo, Victor V.; Tkachuk, Alexandra M.

    1996-04-01

    Antiviral, antibacterial, antitumoral effects of laser coagulation are now of great importance in clinical ophthalmology for different corneal diseases treatment. One can note, that nowadays solid-state free-mode pulsed near-and-mid-infrared lasers with the 1.3 - 3.0 micrometers wavelengths may become widespreadly accepted in this field of ophthalmosurgery. The corneal tissue absorption coefficients for these wavelengths are lying from some parts to several thousand cm-1. Thus, by proper selection of laser wavelength, possibility is appeared to coagulate precisely the seat of pathological alterations without damaging of more deeper, non changed corneal tissue. In our work the comparative experimental study results of rabbit cornea coagulation after exposure with using of different IR lasers (with 1.32; 1.54; 1.96; 2.09 and 2.84 micrometers wavelengths) are presented. Pulse duration was about 10-3 s. The subthreshold, threshold and superthreshold energy levels were studied. Threshold energies were registered if slightly noticed coagulative changes appeared in exposed volume of corneal tissue. The cornea response resulting from laser radiation exposure was evaluated by clinical examination, slit lamp biomicroscopy, light microscopy, fluorescent staining and biochemistry. For all wavelengths initial damage was found within the cornea layers. Superthreshold injury revealed the same picture except that for 1.32 micrometers the threefold increase of the threshold energy caused additionally iris injury. The damages of the cornea were marked near the surface, stretched to more deeper layers, and damage zones were extended from the epithelium for 2.84 micrometers wavelength to whole cornea thickness for 1.32 and 1.54 micrometers wavelengths and have intermediate position for 1.96 and 2.09 micrometers wavelengths, depending on the corneal absorption coefficient. Quantitative results of threshold energy levels were calculated by probit-analysis. The radiant exposure (HD50

  14. Towards in vivo laser coagulation and concurrent optical coherence tomography through double-clad fiber devices

    NASA Astrophysics Data System (ADS)

    Beaudette, Kathy; Lo, William; Villiger, Martin; Shishkov, Milen; Godbout, Nicolas; Bouma, Brett E.; Boudoux, Caroline

    2016-03-01

    There is a strong clinical need for an optical coherence tomography (OCT) system capable of delivering concurrent coagulation light enabling image-guided dynamic laser marking for targeted collection of biopsies, as opposed to a random sampling, to reduce false-negative findings. Here, we present a system based on double-clad fiber (DCF) capable of delivering pulsed laser light through the inner cladding while performing OCT through the core. A previously clinically validated commercial OCT system (NVisionVLE, Ninepoint Medical) was adapted to enable in vivo esophageal image-guided dynamic laser marking. An optimized DCF coupler was implemented into the system to couple both modalities into the DCF. A DCF-based rotary joint was used to couple light to the spinning DCF-based catheter for helical scanning. DCF-based OCT catheters, providing a beam waist diameter of 62μm at a working distance of 9.3mm, for use with a 17-mm diameter balloon sheath, were used for ex vivo imaging of a swine esophagus. Imaging results using the DCF-based clinical system show an image quality comparable with a conventional system with minimal crosstalk-induced artifacts. To further optimize DCF catheter optical design in order to achieve single-pulse marking, a Zemax model of the DCF output and its validation are presented.

  15. Nucleation and particle coagulation experiments in microgravity

    NASA Technical Reports Server (NTRS)

    Nuth, J.

    1987-01-01

    Measurements of the conditions under which carbon, aluminum oxide, and silicon carbide smokes condense and of the morphology and crystal structure of the resulting grains are essential if the nature of the materials ejected into the interstellar medium and the nature of the grains which eventually became part of the proto solar nebular are to be understood. Little information is currently available on the vapor-solid phase transitions of refractory metals and solids. What little experimental data do exist are, however, not in agreement with currently accepted models of the nucleation process for more volatile materials. The major obstacle to performing such experiments in earth-based laboratories is the susceptibility of these systems to convection. Evaporation of refractory materials into a low-pressure environment with a carefully controlled temperature gradient will produce refractory smokes when the critical supersaturation of the system is exceeded. Measurement of the point at which nucleation occurs, via light scattering or extinction, can not only yield nucleation data but also, information on the chemical composition and crystal structure of the condensate. Experimental requirements are presented.

  16. [The coagulation characteristics of human oxyhemoglobin in the presence of a mercury (II) ion in a neutral phosphate buffer].

    PubMed

    Bogdanova, L D; Myshkin, A E

    1990-01-01

    The kinetics of human oxyhemoglobin coagulation in neutral phosphate buffer in the presence of mercury acetate at 20 degrees has been studied using turbidimetric methods. The addition of small amounts of concentrated Hg2+ solution leads to rapid local protein coagulation with subsequent dissolution of the formed coagulate. Coagulation can be inhibited by addition of Tris that binds to mercury ions. The pattern of oxyhemoglobin coagulation is determined by molar Hg2+/protein ration rather than by total Hg2+ concentration.

  17. Production of some coagulant materials from galvanizing workshop waste

    SciTech Connect

    Cici, M.; Cuci, Y.

    1998-09-01

    The aim of this study was to investigate production of some coagulant reagents which have been widely used in all water coagulation treatments using galvanizing waste of the Karadeniz Iron-Steel Plant in Turkey. The waste sample was analyzed by atomic absorption spectrophotometry and a gravimetric procedure. With different techniques, ferric chloro sulfate, FeClSO{sub 4}, ferric sulfate, Fe{sub 2}(SO{sub 4}){sub 3}, sodium ferrate, Na{sub 2}FeO{sub 4} and potassium ferrate, K{sub 2}FeO{sub 4} were obtained from galvanizing waste under laboratory conditions. Then the composition of each reagent was identified by qualitative and quantitative analyses, separately.

  18. SYSTEMIC INFLAMMATION IN XENOGRAFT RECIPIENTS PRECEDES ACTIVATION OF COAGULATION

    PubMed Central

    Ezzelarab, MB; Ekser, B; Azimzadeh, A; Lin, CC; Zhao, Y; Rodriguez, R; Echeverri, GJ; Iwase, H; Long, C; Hara, H; Ayares, D; Pierson, RN; Thomson, AW; Cooper, DKC

    2014-01-01

    Background Dysregulation of coagulation is considered a major barrier against successful pig organ xenotransplantation in nonhuman primates. Inflammation is known to promote activation of coagulation. The role of pro-inflammatory factors as well as the relationship between inflammation and activation of coagulation in xenograft recipients is poorly understood. Methods Baboons received kidney (n=3), heart (n=4) or artery patch (n=8) xenografts from α1,3-galactosyltransferase gene-knockout (GTKO) pigs or GTKO pigs additionally transgenic for human complement regulatory protein CD46 (GTKO/CD46). Immunosuppression (IS) was based on either CTLA4-Ig or anti-CD154 costimulation blockade. Three artery patch recipients did not receive IS. Pro-inflammatory cytokines, chemokines and coagulation parameters were evaluated in the circulation after transplantation. In artery patch recipients, monocytes and dendritic cells (DC) were monitored in peripheral blood. Expression of tissue factor (TF) and CD40 on monocytes and DC were assessed by flow cytometry. C-reactive protein (C-RP) levels in the blood and C-RP deposition in xenografts as well as native organs were evaluated. Baboon and pig C-RP mRNA in heart and kidney xenografts were evaluated. Results In heart and kidney xenograft recipients, the levels of INFγ, TNF-α, IL-12 and IL-8 were not significantly higher after transplantation. However, MCP-1 and IL-6 levels were significantly higher after transplantation, particularly in kidney recipients. Elevated C-RP levels preceded activation of coagulation in heart and kidney recipients, where high levels of C-RP were maintained until the time of euthanasia in both heart and kidney recipients. In artery patch recipients, INFγ, TNF-α, IL-12, IL-8 and MCP-1 were elevated with no IS, while IL-6 was not. With IS, INFγ, TNF-α, IL-12, IL-8 and MCP-1 were reduced, but IL-6 was elevated. Elevated IL-6 levels were observed as early as 2 weeks in artery patch recipients. While IS was

  19. Electrical coagulation: a new process for preparation plant water treatment

    SciTech Connect

    Nickeson, F.H.

    1982-09-01

    The paper describes an electric coagulation process developed by Westinghouse Electric Corp. for the treatment of coal preparation plant water. There are many claims for the system, including improved settling rates of colloidal clays and fines, decreased use of chemicals and no reversion of precipitates to colloidal suspension when disturbed. Other benefits include improved fine coal recovery, reduced filtration time, reduced build-up of fines and clays on dewatering screens, removal of heavy metals and organic carbon from water, increased plant availability and reduced plant maintenance. The treatment process depends on the passage of an AC current through the flow of plant water through a coagulator box. Examples of its use are quoted, in particular at a plant installed for the evaluation of the process.

  20. Coagulation changes following traumatic brain injury and shock.

    PubMed

    Sillesen, Martin

    2014-12-01

    In these studies, we have shown that coagulation and innate immunity pathways respond to trauma within minutes. Furthermore, the appearance of dysfunction of platelets as well as activation of the endothelium is rapidly manifested. Interestingly, many of these changes were attenuated by treatment with valproic acid (VPA). These most notably included coagulation and endothelial activation as well as platelet dysfunction. These results add to the growing body of evidence indicating a protective effect of VPA following trauma, and suggests that this may in part be mediated through an attenuation of the above-mentioned pathways. Furthermore, these results indicate that VPA treatment may be effective in other pathological settings such as coagulopathy following trauma or sepsis.

  1. Weighted Flow Algorithms (WFA) for stochastic particle coagulation

    SciTech Connect

    DeVille, R.E.L.; Riemer, N.; West, M.

    2011-09-20

    Stochastic particle-resolved methods are a useful way to compute the time evolution of the multi-dimensional size distribution of atmospheric aerosol particles. An effective approach to improve the efficiency of such models is the use of weighted computational particles. Here we introduce particle weighting functions that are power laws in particle size to the recently-developed particle-resolved model PartMC-MOSAIC and present the mathematical formalism of these Weighted Flow Algorithms (WFA) for particle coagulation and growth. We apply this to an urban plume scenario that simulates a particle population undergoing emission of different particle types, dilution, coagulation and aerosol chemistry along a Lagrangian trajectory. We quantify the performance of the Weighted Flow Algorithm for number and mass-based quantities of relevance for atmospheric sciences applications.

  2. Blood coagulation and fibrinolysis after experimental subarachnoid hemorrhage.

    PubMed

    Larsen, Carl C; Hansen-Schwartz, Jacob; Nielsen, Jørn D; Astrup, Jens

    2010-09-01

    Aneurysmal rebleeding poses a serious risk in patients with subarachnoid hemorrhage (SAH). Studies have shown that antifibrinolytic therapy with tranexamic acid has a dramatic effect on the rate of rebleeding. Therefore, changes in the fibrinolytic system could be hypothesized. We have used an experimental SAH rat model to demonstrate serial changes in the haemostatic system as evaluated by Thromboelastography (TEG). In the SAH group, a shorter reaction time (R-time) and higher maximum amplitude (MA) were observed. In the saline group, only a shorter R-time was observed. The study has shown that a hypercoagulable state is present immediately after experimental SAH is induced as determined by TEG. The reduction in R-time and rise in MA observed in the SAH group indicate that blood in the subarachnoid space is necessary to accomplish a full systemic coagulation response. This abnormality in coagulation profile seems to be a response to the acute traumatic event caused by induction of SAH.

  3. [The importance of preanalytics for the coagulation laboratory].

    PubMed

    Endler, Georg; Slavka, G; Perkmann, T; Haushofer, A

    2010-05-01

    Due to their complex preanalytics coagulation tests show a higher rate of rejected samples due to insufficient quality and a higher intra- and inter-individual test variability. In the last years several guidelines addressed this issue in an effort to standardize preanalytic procedures. However, in daily laboratory work, these guidelines frequently cannot be fully executed, due to technical limitations or sample transport logistics. In this manuscript several important issues in sample collection, handling and transportation will be discussed. Since the stability and variability of routine coagulation tests such as prothrombin time and partial prothrombin time are significantly influenced by a number of variables such as tube type, manufacturer, reagents used and analyzer systems, it is recommended that each laboratory develops its own manuals for sample collection, based on published data and internal evaluations.

  4. Proteins, Platelets, and Blood Coagulation at Biomaterial Interfaces

    PubMed Central

    Xu, Li-Chong; Bauer, James; Siedlecki, Christopher A.

    2015-01-01

    Blood coagulation and platelet adhesion remain major impediments to the use of biomaterials in implantable medical devices. There is still significant controversy and question in the field regarding the role that surfaces play in this process. This manuscript addresses this topic area and reports on state of the art in the field. Particular emphasis is placed on the subject of surface engineering and surface measurements that allow for control and observation of surface-mediated biological responses in blood and test solutions. Appropriate use of surface texturing and chemical patterning methodologies allow for reduction of both blood coagulation and platelet adhesion, and new methods of surface interrogation at high resolution allow for measurement of the relevant biological factors. PMID:25448722

  5. The vulnerable blood. Coagulation and clot structure in diabetes mellitus.

    PubMed

    Hess, K

    2015-01-01

    Patients with diabetes are at increased risk of cardiovascular morbidity and mortality. While arteriosclerotic lesions have long been recognized as the underlying cause more recent studies suggest that alterations of the blood are also critically involved. Following plaque rupture, adherence of platelets is followed by the formation of a cross-linked fibrin clot. Patients with diabetes exhibit a prothrombotic milieu consisting of hyper reactive platelets, a tight and rigid clot structure which is due to up-regulation of coagulation factors and prolongation of clot lysis. Metabolic alterations as well as inflammatory processes, which are up-regulated in diabetes, are thought to be the main underlying causes. More recently, the complement cascade has emerged as a potential new player in this context with several complement components directly influencing both platelet function and coagulation. This review provides an overview concerning the changes that lead to alterations of platelet function and clot structure in diabetes.

  6. Coagulation of grains in static and collapsing protostellar clouds

    NASA Technical Reports Server (NTRS)

    Weidenschilling, S. J.; Ruzmaikina, T. V.

    1993-01-01

    The wavelength dependence of extinction in the diffuse interstellar medium implies that it is produced by particles of dominant size of approximately 10(exp -5) cm. There is some indication that in the cores of dense molecular clouds, sub-micron grains can coagulate to form larger particles; this process is probably driven by turbulence. The most primitive meteorites (carbonaceous chondrites) are composed of particles with a bimodal size distribution with peaks near 1 micron (matrix) and 1 mm (chondrules). Models for chondrule formation that involve processing of presolar material by chemical reactions or through an accretion shock during infall assume that aggregates of the requisite mass could form before or during collapse. The effectiveness of coagulation during collapse has been disputed; it appears to depend on specific assumptions. The first results of detailed numerical modeling of spatial and temporal variations of particle sizes in presolar clouds, both static and collapsing, is reported in this article.

  7. [Effects of Angelica polysaccharide on blood coagulation and platelet aggregation].

    PubMed

    Yang, Tiehong; Jia, Min; Mei, Qibing; Shang, Peng

    2002-05-01

    To investigate the effects of angelica polysaccharide (AP) on blood coagulation and platelet aggregation. Infrared turbidimetric method was used to estimate platelet aggregation, active partial thromboplastin time (APTT), prothrombin time (PT) and thrombin time (TT); bleeding time (BT) was measured by cutting the mouse's tail and coagulate time (CT) was measured by dropping the blood on carry sheet glass. AP prominently enhanced the platelet aggregation at 5 min, while showed less effects on the maximum platelet aggregation. It also markedly prolonged CT but shortened BT. AP significantly prolonged TT and APTT in dosage of 3 mg/kg and 10 mg/kg, while showed no obvious effect on PT. These results suggest that AP has potent anticoagulant and haemostasis effects. The haemostasis effect is related to promoting platelet aggregation.

  8. The effect of dabigatran on select specialty coagulation assays.

    PubMed

    Adcock, Dorothy M; Gosselin, Robert; Kitchen, Steve; Dwyre, Denis M

    2013-01-01

    Dabigatran etexilate is a new oral anticoagulant that functions as a direct thrombin inhibitor. An inhibitor of thrombin has the potential to interfere with essentially all clot-based coagulation assays and select chromogenic assays, whereas the drug would not be expected to interfere in antigen-based assays. The purpose of this study was to evaluate the effect of dabigatran on various specialized coagulation assays using normal plasma specimens with varying concentrations of dabigatran (the active form of dabigatran etexilate). We have demonstrated that samples containing therapeutic levels of dabigatran may lead to underestimation of intrinsic factor activities with abnormal activated partial thromboplastin time (aPTT) mixing study results and a false-positive factor VIII Bethesda titer; overestimation of protein C and protein S activity and activated protein C resistance ratio when determined using aPTT-based methods; and overestimation of results based on chromogenic anti-IIa assays but no effect on antigen assays and select chromogenic assays.

  9. Development of the selective coagulation process. Final report

    SciTech Connect

    Yoon, R.H.; Luttrell, G.H.

    1992-07-01

    The selective hydrophobic coagulation (SHC) process is based on the recent finding that hydrophobic particles can be selectively coagulated without using traditional agglomerating agents or flocculants. The driving force for the coagulation is the attractive energy between hydrophobic surfaces, an interaction that has been overlooked in classical colloid chemistry. In most cases, selective separations can be achieved using simple pH control to disperse the mineral matter, followed by recovery of the coal coagula using techniques that take advantage of the size enlargement. In the present work, studies have been carried out to further investigate the fundamental mechanisms of the SHC process and the parameters that affect the process of separating coal from the ash-forming minerals and pyritic sulfur. Studies have included direct force measurements of the attractive interaction between model hydrophobic surfaces, in-situ measurements of the size distributions of coagula formed under a variety of operating conditions, and development of a population balance model to describe the coagulation process. An extended DLVO colloid stability model which includes a hydrophobic interaction energy term has also been developed to explain the findings obtained from the experimental studies. In addition to the fundamental studies, bench-scale process development test work has been performed to establish the best possible method of separating the coagula from dispersed mineral matter. Two types of separators, i.e., a sedimentation tank and a rotating drum screen, were examined in this study. The sedimentation tank proved to be the more efficient unit, achieving ash reductions as high as 60% in a single pass while recovering more than 90% of the combustible material. This device, which minimizes turbulence and coagula breakage, was used in subsequent test work to optimize design and operating parameters.

  10. Coagulation Changes During Graded Orhostatic Stress and Recovery

    NASA Astrophysics Data System (ADS)

    Goswami, Nandu; Cvirn, Gerhard; Schlagenhauf, Aaxel; Leschnik, Bettina; Koestenberger, Martin; Roessler, Andreas; Jantscher, Andreas; Waha, James Elvis; Wolf, Sabine; Vrecko, Karoline; Juergens, Guenther; Hinghofer-Szalkay, Helmut

    2013-02-01

    Background: Orthostatic stress has been introduced as a novel paradigm for activating the coagulation system. We examined whether graded orthostatic stress (using head up tilt, HUT + lower body negative pressure, LBNP) until presyncope leads to anti / pro-coagulatory changes and how rapidly they return to baseline during recovery. Methodology: Eight male subjects were enrolled in this study. Presyncopal runs were carried out using HUT + LBNP. At minute zero, the tilt table was brought from 0° (supine) to 70 ° head-up position for 4 min, after which pressure in the LBNP chamber was reduced to -15, -30, and -45 mm Hg every 4 min. At presyncope, the subjects were returned to supine position. Coagulatory responses and plasma mass density (for volume changes) were measured before, during and 20 min after the orthostatic stress. Whole blood coagulation was examined by means of thrombelastometry. Platelet aggregation in whole blood was examined by using impedance aggregometry. Thrombin generation parameters, prothrombin levels, and markers of endothelial activation were measured in plasma samples. Results: At presyncope, plasma volume was 20 % below the initial supine value. Blood cell counts, prothrombin levels, thrombin peak, endogenous thrombin potential (ETP), and tissue factor pathway inhibitor (TFPI) levels increased during the protocol, commensurate with hemoconcentration. The markers of endothelial activation (tissue factor, TF, tissue plasminogen activator, t-PA) and the markers of thrombin generation (Prothrombin fragments 1 and 2, F1+2, and thrombin-antithrombin complex, TAT) increased significantly. During recovery, all the coagulation parameters returned to initial supine values except F1 +2 and TAT. Conclusion: Head-up tilt/LBNP leads to activation of the coagulation system. Some of the markers of thrombin formation are still at higher than supine levels during recovery.

  11. The role of coagulation/fibrinolysis during Streptococcus pyogenes infection

    PubMed Central

    Loof, Torsten G.; Deicke, Christin; Medina, Eva

    2014-01-01

    The hemostatic system comprises platelet aggregation, coagulation and fibrinolysis and is a host defense mechanism that protects the integrity of the vascular system after tissue injury. During bacterial infections, the coagulation system cooperates with the inflammatory system to eliminate the invading pathogens. However, pathogenic bacteria have frequently evolved mechanisms to exploit the hemostatic system components for their own benefit. Streptococcus pyogenes, also known as Group A Streptococcus, provides a remarkable example of the extraordinary capacity of pathogens to exploit the host hemostatic system to support microbial survival and dissemination. The coagulation cascade comprises the contact system (also known as the intrinsic pathway) and the tissue factor pathway (also known as the extrinsic pathway), both leading to fibrin formation. During the early phase of S. pyogenes infection, the activation of the contact system eventually leads to bacterial entrapment within a fibrin clot, where S. pyogenes is immobilized and killed. However, entrapped S. pyogenes can circumvent the antimicrobial effect of the clot by sequestering host plasminogen on the bacterial cell surface that, after conversion into its active proteolytic form, plasmin, degrades the fibrin network and facilitates the liberation of S. pyogenes from the clot. Furthermore, the surface-localized fibrinolytic activity also cleaves a variety of extracellular matrix proteins, thereby enabling S. pyogenes to migrate across barriers and disseminate within the host. This review summarizes the knowledge gained during the last two decades on the role of coagulation/fibrinolysis in host defense against S. pyogenes as well as the strategies developed by this pathogen to evade and exploit these host mechanisms for its own benefit. PMID:25309880

  12. The use of argon beam coagulation in pressure sore reconstruction.

    PubMed

    Buck, Donald W; Lewis, Victor L

    2009-12-01

    Pressure sores are a significant source of physical and financial burden for debilitated patients. When conservative measures fail, surgical reconstruction with myocutaneous flaps may be the last hope for cure and/or improved quality of life in these patients. Adequate haemostasis is an integral component of these reconstructive procedures, as bleeding and haematoma formation can lead to increased morbidity. This study was designed to investigate the use of argon beam coagulation in patients undergoing bony debridement and subsequent pressure sore reconstruction with myocutaneous flaps. The clinical records of 34 patients undergoing pressure sore reconstruction with the use of argon beam coagulation from 2004 to 2006 at an academic institution were reviewed and outcomes were assessed. Reconstruction was performed by a single surgeon on 34 patients (31 men, three women; mean age 41+/-15 years), with a total of 41 pressure sores. Thirteen (32.5%) patients had evidence of osteomyelitis preoperatively and five (12.5%) had previous coccygectomies secondary to infection. Twenty-six (65%) of the pressure sores were treated with hamstring V-Y musculocutaneous flaps, 10 (25%) with gluteal flaps, and four (10%) with tensor fascia lata flaps. Overall, suture line dehiscence occurred in six (15%) cases, flap failure and pressure sore recurrence occurred in six (15%) cases, an abscess developed in one (2.5%) case, and a sinus tract with a superficial wound developed in one (2.5%) case. There were no complications related to haemostasis, including excessive bleeding or haematoma formation. Argon beam coagulation is an efficacious tool for achieving adequate haemostasis during pressure sore reconstruction, particularly when significant bony debridement is involved. The use of argon beam coagulation does not result in an increased complication or recurrence rate when compared with conventional electrocautery methods.

  13. Coagulation assessment by rotation thrombelastometry in normal pregnancy.

    PubMed

    Huissoud, Cyril; Carrabin, Nicolas; Benchaib, Mehdi; Fontaine, Oriane; Levrat, Albrice; Massignon, Denis; Touzet, Sandrine; Rudigoz, René-Charles; Berland, Michel

    2009-04-01

    We analysed changes in coagulation during normal pregnancy with a novel point-of-care device based on thrombelastometry (ROTEM). We compared the results obtained with those of standard coagulation tests in 104 patients: 20 non-pregnant women (controls) and 84 women in the first (T1, n = 17), second (T2, n = 9) and third (T3, n = 58) trimesters of pregnancy. We measured the clotting time (CT), the maximum clot firmness (MCF), the early clot amplitude at 5 and 15 minutes (CA(5), CA(15)) and the clot lysis index (CLI(30)) with four tests containing specific reagents. (a) The INTEM test involving ellagic acid activated the intrinsic pathway and (b) the EXTEM test using tissue factor triggered the extrinsic pathway; (c) The FIBTEM test based on a platelet inhibitor (cytochalasin D) evaluated the contribution of fibrinogen to clot formation and (d) the APTEM test was similar to the EXTEM but was based on inhibition in vitro of fibrinolysis by aprotinin. CT and CLI(30) were not significantly modified during pregnancy whereas MCF, CA(5) and CA(15) (INTEM, EXTEM, FIBTEM) increased significantly between the second and third trimesters (e.g. median [interquartile range]: MCF-FIBTEM, 13 [11-16] mm vs. 19 [17-23] mm, respectively, in controls and T3, p < 0.001). EXTEM values were not significantly different from those measured with APTEM. There were significant correlations between the results obtained with ROTEM and those from standard coagulation tests. ROTEM analysis showed a marked increase in coagulability during normal pregnancy. ROTEM values may serve as the basis for future studies in pregnant women.

  14. Dust to planetesimals - Settling and coagulation in the solar nebula

    SciTech Connect

    Weidenschilling, S.J.

    1980-10-01

    The behavior of solid particles in a low-mass solar nebula during settling to the central plane and the formation of planetesimals is discussed. The gravitational instability in a dust layer and collisional accretion are examined as possible mechanisms of planetesimal formation. The shear between the gas and a dust layer is considered along with the differences in the planetesimal formation mechanisms between the inner and outer nebula. A numerical model for computing simultaneous coagulation and settling is described.

  15. Effect of Dust Coagulation Dynamics on the Geometry of Aggregates

    NASA Technical Reports Server (NTRS)

    Nakamura, R.

    1996-01-01

    Master equation gives a more fundamental description of stochastic coagulation processes rather than popular Smoluchowski's equation. In order to examine the effect of the dynamics on the geometry of resulting aggregates, we study Master equation with a rigorous Monte Carlo algorithm. It is found that Cluster-Cluster aggregation model is a good approximation of orderly growth and the aggregates have fluffy structures with a fractal dimension approx. 2. A scaling analysis of Smoluchowski's equation also supports this conclusion.

  16. Commonly Used Dietary Supplements on Coagulation Function during Surgery

    PubMed Central

    Wang, Chong-Zhi; Moss, Jonathan; Yuan, Chun-Su

    2015-01-01

    Abstract Background Patients who undergo surgery appear to use dietary supplements significantly more frequently than the general population. Because they contain pharmacologically active compounds, dietary supplements may affect coagulation and platelet function during the perioperative period through direct effects, pharmacodynamic interactions, and pharmacokinetic interactions. However, in this regard, limited studies have been conducted that address the pharmacological interactions of dietary supplements. To avoid possible bleeding risks during surgery, information about the potential complications of dietary supplements during perioperative management is important for physicians. Methods Through a systematic database search of all available years, articles were identified in this review if they included dietary supplements and coagulation/platelet function, while special attention was paid to studies published after 1990. Results Safety concerns are reported in commercially available dietary supplements. Effects of the most commonly used natural products on blood coagulation and platelet function are systematically reviewed, including 11 herbal medicines (echinacea, ephedra, garlic, ginger, ginkgo, ginseng, green tea, kava, saw palmetto, St John’s wort, and valerian) and four other dietary supplements (coenzyme Q10, glucosamine and chondroitin sulfate, fish oil, and vitamins). Bleeding risks of garlic, ginkgo, ginseng, green tea, saw palmetto, St John’s wort, and fish oil are reported. Cardiovascular instability was observed with ephedra, ginseng, and kava. Pharmacodynamic and pharmacokinetic interactions between dietary supplements and drugs used in the perioperative period are discussed. Conclusions To prevent potential problems associated with the use of dietary supplements, physicians should be familiar with the perioperative effects of commonly used dietary supplements. Since the effects of dietary supplements on coagulation and platelet function are

  17. Dust to planetesimals - Settling and coagulation in the solar nebula

    NASA Technical Reports Server (NTRS)

    Weidenschilling, S. J.

    1980-01-01

    The behavior of solid particles in a low-mass solar nebula during settling to the central plane and the formation of planetesimals is discussed. The gravitational instability in a dust layer and collisional accretion are examined as possible mechanisms of planetesimal formation. The shear between the gas and a dust layer is considered along with the differences in the planetesimal formation mechanisms between the inner and outer nebula. A numerical model for computing simultaneous coagulation and settling is described.

  18. Sonoclot evaluation of whole blood coagulation in healthy adult dogs.

    PubMed

    Babski, Danielle M; Brainard, Benjamin M; Krimer, Paula M; Ralph, Alan G; Pittman, Jennifer R; Koenig, Amie

    2012-12-01

    To establish a standard protocol for analysis of canine whole blood and generate reference intervals for healthy dogs using the Sonoclot analyzer, and to compare Sonoclot values to standard and viscoelastic coagulation tests. Prospective study. Veterinary University research facility and teaching hospital. Twelve healthy random source dogs and 52 healthy dogs from the general veterinary school population. Blood sampling for viscoelastic coagulation testing. Blood was collected from 12 healthy adult dogs by jugular venipuncture. After a rest period at room temperature of 30, 60, or 120 minutes, 340 μL of citrated blood was added to 20 μL of 0.2 M CaCl(2) in 1 of 2 cuvette types warmed to 37° C. Cuvettes contained a magnetic stir-bar with glass beads (gbACT+) or only a magnetic stir-bar (nonACT). Reference interval samples were collected from 52 healthy adult dogs and analyzed in duplicate. The ACT, CR, and PF were not affected by duration of rest period for either cuvette type. ACT variability was decreased when using gbACT+ cuvettes (P < 0.05). In normal dogs reference intervals (mean ± 2 SD) using gbACT+ cuvettes were: ACT 56.0-154.0 seconds, CR 14.85-46.0, and PF 2.1-4.05. ACT correlated to TEG R-time, K-time, and angle, while CR correlated with all TEG parameters. Fibrinogen correlated with ACT, CR, and PF. Sonoclot did not correlate with other common coagulation tests. Sonoclot provides viscoelastic evaluation of canine whole blood coagulation and correlated to several TEG parameters and fibrinogen. A standard protocol and reference intervals were established. © Veterinary Emergency and Critical Care Society 2012.

  19. Effects of Oritavancin on Coagulation Tests in the Clinical Laboratory.

    PubMed

    Belley, Adam; Robson, Richard; Francis, John L; Adcock, Dorothy M; Tiefenbacher, Stefan; Rubino, Christopher M; Moeck, Greg; Sylvester, David; Dudley, Michael N; Loutit, Jeffery

    2017-02-01

    Previous studies have shown that some lipoglycopeptide and lipopeptide antimicrobial agents may cause falsely elevated values for some phospholipid-dependent coagulation tests. The effect of oritavancin, a lipoglycopeptide antibiotic, on coagulation test results was explored using pooled human plasma samples spiked with drug and in a clinical study after an infusion of a single 1,200-mg intravenous dose of oritavancin in normal healthy volunteers. Pooled plasma with oritavancin added ex vivo showed concentration-dependent prolongation of prothrombin time/international normalized ratio (PT/INR), activated partial thromboplastin time (aPTT), and dilute Russell viper venom time (DRVVT) test results. In contrast, oritavancin had no effect on the activated protein C resistance assay, chromogenic anti-factor Xa assay (anti-FXa), thrombin time, and an immunoassay for the laboratory diagnosis of heparin-induced thrombocytopenia. In participants that received a single dose of oritavancin, elevations in PT/INR result, aPTT, DRVVT, activated clotting time, and silica clotting time occurred, with the maximum times to resolution of test interference determined to be 12, 120, 72, 24, and 18 h, respectively. The anti-FXa assay was unaffected, whereas transient elevations in D dimer levels were observed in 30% of participants, with a maximum time to resolution of 72 h. Although oritavancin has no impact on the coagulation system in vivo, a single dose of oritavancin can produce falsely elevated values of some coagulation tests used to monitor hemostasis. The interference of oritavancin on affected tests is transient, and the test results revert to normal ranges within specified times after dosing. Copyright © 2017 American Society for Microbiology.

  20. Effect of Dust Coagulation Dynamics on the Geometry of Aggregates

    NASA Technical Reports Server (NTRS)

    Nakamura, R.

    1996-01-01

    Master equation gives a more fundamental description of stochastic coagulation processes rather than popular Smoluchowski's equation. In order to examine the effect of the dynamics on the geometry of resulting aggregates, we study Master equation with a rigorous Monte Carlo algorithm. It is found that Cluster-Cluster aggregation model is a good approximation of orderly growth and the aggregates have fluffy structures with a fractal dimension approx. 2. A scaling analysis of Smoluchowski's equation also supports this conclusion.

  1. Differences in Coagulation Between Hemodialysis and Peritoneal Dialysis

    PubMed Central

    Brophy, Donald F.; Carl, Daniel E.; Mohammed, Bassem M.; Song, Jingmei; Martin, Erika J.; Bostic, Jessica L.; Gehr, Todd W.B.

    2014-01-01

    ♦ Background: End-stage renal disease patients have significant cardiovascular morbidity and mortality, but little is known about differences in coagulation profiles between patients on hemodialysis (HD) and on peritoneal dialysis (PD). Given their long-term exposure to glucose-based dialysate, patients on PD can experience metabolic derangements. Theoretically, that exposure should create a more prothrombotic environment than occurs in HD patients. The objective of the present study was to quantify potential differences in baseline coagulation between PD and HD patients. ♦ Methods: Our single-center cross-sectional study at a large academic health science center enrolled 50 age-, race-, and sex-matched subjects (10 control subjects, 20 HD patients, and 20 PD patients). Measurements included platelet function, platelet receptor distribution, and coagulation dynamics by thromboelastography and Hemodyne hemostasis assay (Hemodyne, Richmond, VA, USA). ♦ Results: Compared with healthy control subjects, patients on both forms of dialysis showed prothrombotic coagulation protein profiles. The tissue-factor pathway was markedly elevated in both groups, but PD was associated with significantly greater concentrations of tissue factor (p = 0.0056) and tissue-factor pathway inhibitor (p = 0.0138). Similarly, compared with patients receiving HD, patients on PD had greater concentrations of fibrinogen (p = 0.0325), which corresponded with platelet hyperfunction as measured by platelet contractile force and clot elastic modulus (p = 0.003 and 0.017 respectively, compared with values in HD patients). Platelet receptor distribution was similar between the groups. ♦ Conclusions: Compared with patients on HD, patients on PD appear to have a more prothrombotic profile. The clinical relevance of these findings needs to be studied in a prospective manner. PMID:24293664

  2. Sepsis-Associated Disseminated Intravascular Coagulation and Thromboembolic Disease

    PubMed Central

    Semeraro, Nicola; Ammollo, Concetta T.; Semeraro, Fabrizio; Colucci, Mario

    2010-01-01

    Sepsis is almost invariably associated with haemostatic abnormalities ranging from subclinical activation of blood coagulation (hypercoagulability), which may contribute to localized venous thromboembolism, to acute disseminated intravascular coagulation (DIC), characterized by massive thrombin formation and widespread microvascular thrombosis, partly responsible of the multiple organ dysfunction syndrome (MODS), and subsequent consumption of platelets and coagulation proteins causing, in most severe cases, bleeding manifestations. There is general agreement that the key event underlying this life-threatening sepsis complication is the overwhelming inflammatory host response to the infectious agent leading to the overexpression of inflammatory mediators. Mechanistically, the latter, together with the micro-organism and its derivatives, causes DIC by 1) up-regulation of procoagulant molecules, primarily tissue factor (TF), which is produced mainly by stimulated monocytes-macrophages and by specific cells in target tissues; 2) impairment of physiological anticoagulant pathways (antithrombin, protein C pathway, tissue factor pathway inhibitor), which is orchestrated mainly by dysfunctional endothelial cells (ECs); and 3) suppression of fibrinolysis due to increased plasminogen activator inhibitor-1 (PAI-1) by ECs and likely also to thrombin-mediated activation of thrombin-activatable fibrinolysis inhibitor (TAFI). Notably, clotting enzymes non only lead to microvascular thrombosis but can also elicit cellular responses that amplify the inflammatory reactions. Inflammatory mediators can also cause, directly or indirectly, cell apoptosis or necrosis and recent evidence indicates that products released from dead cells, such as nuclear proteins (particularly extracellular histones), are able to propagate further inflammation, coagulation, cell death and MODS. These insights into the pathogenetic mechanisms of DIC and MODS may have important implications for the

  3. Influence of Blood Lipids on Global Coagulation Test Results

    PubMed Central

    Kim, Jung-Ah; Kim, Ji-Eun; Song, Sang Hoon

    2015-01-01

    Background High levels of blood lipids have been associated with high levels of coagulation factors. We investigated whether blood lipids influence the results of global coagulation tests, including prothrombin time (PT), activated partial thromboplastin time (aPTT), and thrombin generation assay (TGA). Methods PT, aPTT, and TGA, along with procoagulant and anticoagulant factors, were measured in 488 normal individuals. Vitamin K status was assessed with prothrombin-induced by vitamin K absence-II (PIVKA-II). Results The procoagulant factors II, VII, IX, X, and XI and anticoagulant factors protein C and protein S showed significant correlations with triglyceride, and the procoagulant factors II, V, VII, IX, X, XI, and XII and anticoagulant factors antithrombin and protein C correlated with total cholesterol. There were no correlations of blood lipid levels with PIVKA-II levels. Subjects with high triglyceride levels (≥200 mg/dL) showed shorter PT values than those with lower triglyceride levels. However, aPTT value was not changed in terms of blood lipid levels. In both 1 and 5 pM tissue factor-induced TGAs, subjects in the high-triglyceride or high-cholesterol groups (≥240 mg/dL) had high levels of lag time, time-to-peak, and endogenous thrombin potential. Total cholesterol was a significant determinant of PT and TGA values. Conclusion High blood lipids were related with increased coagulation activity in a normal population. Our findings are expected to help interpret the global coagulation test results in individuals with high lipid levels. PMID:25553275

  4. Influence of blood lipids on global coagulation test results.

    PubMed

    Kim, Jung-Ah; Kim, Ji-Eun; Song, Sang Hoon; Kim, Hyun Kyung

    2015-01-01

    High levels of blood lipids have been associated with high levels of coagulation factors. We investigated whether blood lipids influence the results of global coagulation tests, including prothrombin time (PT), activated partial thromboplastin time (aPTT), and thrombin generation assay (TGA). PT, aPTT, and TGA, along with procoagulant and anticoagulant factors, were measured in 488 normal individuals. Vitamin K status was assessed with prothrombin-induced by vitamin K absence-II (PIVKA-II). The procoagulant factors II, VII, IX, X, and XI and anticoagulant factors protein C and protein S showed significant correlations with triglyceride, and the procoagulant factors II, V, VII, IX, X, XI, and XII and anticoagulant factors antithrombin and protein C correlated with total cholesterol. There were no correlations of blood lipid levels with PIVKA-II levels. Subjects with high triglyceride levels (≥200 mg/dL) showed shorter PT values than those with lower triglyceride levels. However, aPTT value was not changed in terms of blood lipid levels. In both 1 and 5 pM tissue factor-induced TGAs, subjects in the high-triglyceride or high-cholesterol groups (≥240 mg/dL) had high levels of lag time, time-to-peak, and endogenous thrombin potential. Total cholesterol was a significant determinant of PT and TGA values. High blood lipids were related with increased coagulation activity in a normal population. Our findings are expected to help interpret the global coagulation test results in individuals with high lipid levels.

  5. Blood coagulation activation and fibrinolysis during a downhill marathon run.

    PubMed

    Sumann, Günther; Fries, Dietmar; Griesmacher, Andrea; Falkensammer, Gerda; Klingler, Anton; Koller, Arnold; Streif, Werner; Greie, Sven; Schobersberger, Beatrix; Schobersberger, Wolfgang

    2007-07-01

    Prolonged physical exercise is associated with multiple changes in blood hemostasis. Eccentric muscle activation induces microtrauma of skeletal muscles, inducing an inflammatory response. Since there is a link between inflammation and coagulation we speculated that downhill running strongly activates the coagulation system. Thirteen volunteers participated in the Tyrolean Speed Marathon (42,195 m downhill race, 795 m vertical distance). Venous blood was collected 3 days (T1) and 3 h (T2) before the run, within 30 min after finishing (T3) and 1 day thereafter (T4). We measured the following key parameters: creatine kinase, myoglobin, thrombin-antithrombin complex, prothrombin fragment F1 + 2, D-dimer, plasmin-alpha(2)-antiplasmin complexes, tissue-type plasminogen activator antigen, plasminogen-activator-inhibitor-1 antigen and thrombelastography with ROTEM [intrinsic pathway (InTEM) clotting time, clot formation time, maximum clot firmness, alpha angle]. Thrombin generation was evaluated by the Thrombin Dynamic Test and the Technothrombin TGA test. Creatine kinase and myoglobin were elevated at T3 and further increased at T4. Thrombin-antithrombin complex, prothrombin fragment F1 + 2, D-dimer, plasmin-alpha(2)-antiplasmin complexes, tissue-type plasminogen activator antigen and plasminogen-activator-inhibitor-1 antigen were significantly increased at T3. ROTEM analysis exhibited a shortening of InTEM clotting time and clot formation time after the marathon, and an increase in InTEM maximum clot firmness and alpha angle. Changes in TGA were indicative for thrombin generation after the marathon. We demonstrated that a downhill marathon induces an activation of coagulation, as measured by specific parameters for coagulation, ROTEM and thrombin generation assays. These changes were paralleled by an activation of fibrinolysis indicating a preserved hemostatic balance.

  6. Effect of microparticulated whey proteins on milk coagulation properties.

    PubMed

    Sturaro, A; Penasa, M; Cassandro, M; Varotto, A; De Marchi, M

    2014-11-01

    The enhancement of milk coagulation properties (MCP) and the reuse of whey produced by the dairy industry are of great interest to improve the efficiency of the cheese-making process. Native whey proteins (WP) can be aggregated and denatured to obtain colloidal microparticulated WP (MWP). The objective of this study was to assess the effect of MWP on MCP; namely, rennet coagulation time (RCT), curd-firming time, and curd firmness 30 min after rennet addition. Six concentrations of MWP (vol/vol; 1.5, 3.0, 4.5, 6.0, 7.5, and 9.0%) were added to 3 bulk milk samples (collected and analyzed during 3 d), and a sample without MWP was used as control. Within each day of analysis, 6 replicates of MCP for each treatment were obtained, changing the position of the treatment in the rack. For control samples, 2 replicates per day were performed. In addition to MCP, WP fractions were measured on each treatment during the 3 d of analysis. Milk coagulation properties were measured on 144 samples by using a Formagraph (Foss Electric, Hillerød, Denmark). Increasing the amount of MWP added to milk led to a longer RCT. In particular, significant differences were found between RCT of the control samples (13.5 min) and RCT of samples with 3.0% (14.6 min) or more MWP. A similar trend was observed for curd-firming time, which was shortest in the control samples and longest in samples with 9.0% MWP (21.4 min). No significant differences were detected for curd firmness at 30 min across concentrations of MWP. Adjustments in cheese processing should be made when recycling MWP, in particular during the coagulation process, by prolonging the time of rennet activity before cutting the curd.

  7. Effect of second coagulant addition on coagulation efficiency, floc properties and residual Al for humic acid treatment by Al13 polymer and polyaluminum chloride (PACl).

    PubMed

    Xu, Weiying; Gao, Baoyu; Wang, Yan; Yue, Qinyan; Ren, Haijing

    2012-05-15

    Influence of second dose on coagulation efficiency, floc re-growth, fractal structure and residual Al of the effluent in humic acid (HA) coagulation with Al(13) polymer ([Al(13)O(4)(OH)(24)(H(2)O)(12)](7+)) and PACl were comparatively investigated in this study. Effects of breakage shear on the floc properties generated in the coagulation with and without additional dose were also investigated. The results indicated that additional dose during breakage could essentially improve the HA removal efficiency and floc re-growth in both Al(13) and PACl coagulations. Second doses of Al(13) at 0.5 and 1.0mg/L resulted in better turbidity and UV(254) removal as well as floc re-growth rather than higher additional dose of 1.5 and 2.0mg/L; while in PACl coagulation, more efficient HA removal and better floc re-growth were obtained at higher additional doses (1.0, 1.5 and 2.0mg/L). Small additional Al(13) could apparently increase the D(f) of re-formed flocs while the additional PACl displayed inconspicuous effect on floc D(f). The additional coagulant dose could alleviate the further decrease of re-grown floc size with increased breakage shear for both coagulants. The residual Al analysis implied that two-stage addition contributed to lower residual Al in effluent than one-time addition mode with the same total coagulant concentration.

  8. Two distinct forms of Factor VIII coagulant protein in human plasma. Cleavage by thrombin, and differences in coagulant activity and association with von Willebrand factor.

    PubMed Central

    Weinstein, M J; Chute, L E

    1984-01-01

    We have characterized Factor VIII coagulant protein, present in normal human plasma, that reacts with a specific human 125I-labeled anti-human VIII:C antigen Fab antibody fragment. Two major Factor VIII coagulant antigen populations were present. The first, approximately 85% of the total antigen, was bound to von Willebrand factor and when tested in a standard one-stage assay had Factor VIII coagulant activity. The second antigenic population, eluting near fibrinogen when plasma was gel filtered, was not bound to von Willebrand protein, did not have Factor VIII coagulant activity unless activated, but did block anti-VIII:C Fab neutralization of clotting activity. The two antigenic populations were separable by cryoprecipitation and agarose gel electrophoresis. Although the two antigenic populations differed in their Factor VIII coagulant activity and in their binding to von Willebrand factor, the principal member of both populations is of mol wt 2.4 X 10(5). Both antigens, when proteolyzed by thrombin, were quickly converted to a 1 X 10(5)-mol wt form in association with the appearance of VIII:C activity. The 1 X 10(5)-mol wt antigen was further slowly degraded to an 8 X 10(4)-mol wt form while Factor VIII coagulant activity declined. These results demonstrate the presence of an inactive Factor VIII coagulant protein in plasma, not associated with von Willebrand factor, that can react with thrombin to yield Factor VIII coagulant activity. Images PMID:6421875

  9. Decolorization and COD reduction of dyeing wastewater from a cotton textile mill using thermolysis and coagulation.

    PubMed

    Kumar, Pradeep; Prasad, B; Mishra, I M; Chand, Shri

    2008-05-01

    The decolorization and reduction of COD of dyeing wastewater from a cotton textile mill was conducted using catalytic thermal treatment (thermolysis) accompanied with/without coagulation. Thermolysis in presence of a homogeneous copper sulphate catalyst was found to be the most effective in comparison to other catalysts (FeCl(3), FeSO(4), CuO, ZnO and PAC) used. A maximum reduction of chemical oxygen demand (COD) and color of dyeing wastewater of 66.85% and 71.4%, respectively, was observed with a catalyst concentration of 5 kg/m(3) at pH 8. Commercial alum was found most effective coagulant among various coagulants (aluminum potassium sulphate, PAC, FeCl(3) and FeSO(4)) tested during coagulation operations, resulting in 58.57% COD and 74% color reduction at pH 4 and coagulant dose of 5 kg/m(3). Coagulation of the clear fluid (supernatant) obtained after treatment by thermolysis at the conditions previously used resulted in an overall reduction of 89.91% COD and 94.4% color at pH 4 and a coagulant dose of 2 kg/m(3). The application of thermolysis followed by coagulation, thus, is the most effective treatment method in removing nearly 90% COD and 95% color at a lower dose of coagulant (2 kg/m(3)). The sludge thus produced would contain lower inorganic mass coagulant and, therefore, less amount of inorganic sludge.

  10. Kinetic Modeling of Oxidative Coagulation for Arsenic Removal

    SciTech Connect

    Kim, Jin-Wook; Kramer, Timothy A.

    2004-03-31

    A model of oxidative coagulation consisting of Fenton's reagent (Fe(II)/H2O2 at pH 7.0) was established. The optimum condition was found when the mole ratio of As(III):H2O2:Fe(II)=1:15:20. In this optimum condition, all of Fe(II) was converted to HFO (am-Fe(OH)3) and precipitated to be used as the oxidized arsenic(V) adsorbent and particle coagulant. Two sorption models consisting of a surface complexation model and a kinetic model were developed and coupled. Using the coupled sorption model, the kinetics of HFO surface charge/potential during As(V) sorption was calculated. Further, during arsenic sorption, the colloid stability kinetics resulting from the perikinetic coagulation mechanism was calculated by considering interparticle forces. Colloid surface potential was decreased from 60 mv to 12 mv in proportion to the amount of arsenic adsorbed onto HFO and this surface potential directly affected the colloid stability (collision efficiency).

  11. Coagulation-flocculation of marine Chlorella sp. for biodiesel production.

    PubMed

    Sanyano, Naruetsawan; Chetpattananondh, Pakamas; Chongkhong, Sininart

    2013-11-01

    Harvesting of marine Chlorella sp. by autoflocculation and flocculation by addition of coagulant with pH adjustment was investigated in this study. Autoflocculation provided low efficiency. Response surface methodology was employed to optimize the coagulant dosage and pH for flocculation. Aluminium sulfate and ferric chloride were investigated coagulants. The empirical models from RSM are in a good agreement with the experimental results. The optimum flocculation was achieved at ferric chloride dosage 143 mg/L, pH 8.1 and settling time 40 min. Biomass concentration also presented the significant effect on harvesting efficiency. Lipid extracted from marine Chlorella sp. cultivated in urea fertilizer medium with hexane as a solvent is suitable to produce biodiesel according to it contains high proportion of saturated fatty acids. The crude lipid should be purified to remove some impurities before making biodiesel. As the free fatty acid content was higher than 1% a two-step biodiesel production is recommended. Copyright © 2013 Elsevier Ltd. All rights reserved.

  12. Coagulation for removal of humic materials from groundwater

    SciTech Connect

    Spengler, S.; Benefield, L.; Jenkins, S.R.

    1983-01-01

    The use of powdered activated carbon and alum-polyelectrolyte coagulation was evaluated to determine its effectiveness in reducing the color-causing organics in a highly colored synthetic groundwater. These organics have been shown to be the precursors for trihalomethane formation in chlorinated drinking waters. Using a series of jar tests, an optimum pH range for hydroxylated aromatics removal using alum-polyelectrolyte coagulation was found to occur near a pH of 5.0. For this pH a relationship between initial hydroxylated aromatics concentration per mg/L alum added and residual hydroxylated aromatics concentration was developd. A ratio value of less than 0.05 was found to be required to reduce the hydroxylated aromatics concentration below 1 mg/L. The use of powdered activated carbon as a modification to the conventional coagulation process was found to be ineffective for this synthetic groundwater. Less than a 5% reduction in hydroxylated aromatics was realized at a powdered activated carbon dosage of 300 mg/L.

  13. Slaughterhouse Wastewater Treatment by Combined Chemical Coagulation and Electrocoagulation Process

    PubMed Central

    Bazrafshan, Edris; Kord Mostafapour, Ferdos; Farzadkia, Mehdi; Ownagh, Kamal Aldin; Mahvi, Amir Hossein

    2012-01-01

    Slaughterhouse wastewater contains various and high amounts of organic matter (e.g., proteins, blood, fat and lard). In order to produce an effluent suitable for stream discharge, chemical coagulation and electrocoagulation techniques have been particularly explored at the laboratory pilot scale for organic compounds removal from slaughterhouse effluent. The purpose of this work was to investigate the feasibility of treating cattle-slaughterhouse wastewater by combined chemical coagulation and electrocoagulation process to achieve the required standards. The influence of the operating variables such as coagulant dose, electrical potential and reaction time on the removal efficiencies of major pollutants was determined. The rate of removal of pollutants linearly increased with increasing doses of PACl and applied voltage. COD and BOD5 removal of more than 99% was obtained by adding 100 mg/L PACl and applied voltage 40 V. The experiments demonstrated the effectiveness of chemical and electrochemical techniques for the treatment of slaughterhouse wastewaters. Consequently, combined processes are inferred to be superior to electrocoagulation alone for the removal of both organic and inorganic compounds from cattle-slaughterhouse wastewater. PMID:22768233

  14. Hyperprolactinemia during antipsychotics treatment increases the level of coagulation markers

    PubMed Central

    Ishioka, Masamichi; Yasui-Furukori, Norio; Sugawara, Norio; Furukori, Hanako; Kudo, Shuhei; Nakamura, Kazuhiko

    2015-01-01

    Objective The strong association between psychiatric patients who receive antipsychotics and the incidence of venous thromboembolism (VTE) is known. Although previous reports suggest that hyperprolactinemia often increases markers of activated coagulation, few studies have examined the direct relationship between the prolactin level elevated by antipsychotics and activated markers of activated coagulation. Method The participants included 182 patients with schizophrenia (male =89, female =93) who received antipsychotic treatments for at least 3 months. Markers of VTE (D-dimer, fibrin/fibrinogen degradation products, and thrombin–antithrombin complex) and serum prolactin concentrations were measured. Results Prolactin levels were significantly correlated with the logarithmic transformation of the D-dimer (r=0.320, P=0.002) and fibrin/fibrinogen degradation product levels (r=0.236, P=0.026) but not of the thrombin–antithrombin complex level (r=0.117, ns) among men. However, no correlations were found between the VTE markers and prolactin levels among women. These results were confirmed using multiple regression analyses that included demographic factors and antipsychotic dosages. Conclusion The current study indicates that hyperprolactinemia is associated with an increase in markers of activated coagulation among men receiving antipsychotics. This finding clinically implies that monitoring and modulating prolactin levels among men are important to decrease the risk of VTE. PMID:25750528

  15. Coagulation and rheological behaviors of soy milk colloidal dispersions.

    PubMed

    Fujii, Tomoyuki

    2017-04-01

    Coagulation and rheological behaviors of soy milk are reviewed from the viewpoint of colloidal dispersion system. From the results of relative viscosity in the range of small oil body volume fractions, oil bodies containing oleosin behave as rigid spheres. The Krieger-Dougherty equation was found to describe relative viscosities well under high oil body volume fraction. These results indicate that oil bodies in soy milk behave as though suspended matter. Cross-linking between colloid particles occurs when the coagulant is added, and bulky clusters are formed. The viscosity rises due to the hydrodynamic effects of these bulky clusters. A new viscosity equation that combines the Krieger-Dougherty equation and the effective volume fraction could describe the viscos behavior well for wide range of solid contents. Tofu is made by adding a coagulant to soy milk. For lipid concentrations of less than 2%, rupture stress increases depending on the lipid concentration, whereas at concentrations of more than 3%, rupture stress tends to decline. Kinugoshi tofu samples have a maximum value for rupture stress depending on lipid concentration. Digestion of oleosin in high-fat soy milk using papain treatment results in the centrifugal separation of soy milk cream easily. This result indicates that oleosin let oil bodies in soy milk stable. Therefore, it is important to control the state of soy milk colloidal dispersions.

  16. COAGULATION PARAMETERS IN THE AMERICAN FLAMINGO (PHOENICOPTERUS RUBER).

    PubMed

    Gardhouse, Sara; Eshar, David; Beaufrère, Hugues

    2016-06-01

    American flamingos ( Phoenicopterus ruber ) are commonly kept in zoologic collections. When presented to veterinarians in states of health and illness, evaluation of selected coagulation parameters can aid in assessment of various coagulopathies, as well as other disease processes such as septicemia, vasculitis, and hepatic disease. Sixteen American flamingos (eight males, eight females) were presented for annual health evaluations. A blood sample was collected from the medial metatarsal vein, and prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, and fibrin degradation products (FDPs) were evaluated using an automated hemostasis analyzer. Results were reported as median and range (minimum-maximum): PT = 72.7 (39 to >100 sec), APTT = 97.5 (6.1 to >200 sec), fibrinogen = 184 (138-364 mg/dl), and FDPs = <5 (<5 to >20 μg/ml). To the authors' knowledge, this is the first report of coagulation parameters in American flamingos. Knowledge of coagulation parameters will allow for better clinical assessment and management of American flamingos.

  17. Trombocytopenia: one of the markers of disseminated intravascular coagulation.

    PubMed

    Ten Cate, Hugo

    Disseminated intravascular coagulation (DIC) is a complication of a variety of severe underlying diseases and a contributing factor in multi-organ failure and death. DIC is diagnosed on the basis of clinical findings (organ failure, bleeding) and laboratory abnormalities. The laboratory data include (repeated) measurements of platelet count and global clotting tests, to which more specific and sensitive tests for activated coagulation are added. The focus of this paper is on thrombocytopenia (platelet count < 100 x 103/microl) as a marker in DIC. First, in patients with suspected DIC it is imperative to consider alternative causes of thrombocytopenia,such as related to heparin use (heparin induced thrombocytopenia II) or thrombocytopenic purpura. Second, the observation of thrombocytopenia in relation to DIC should be interpreted as a marker of advanced or overt DIC and not as an early indicator. According to recommended guidelines measurements of platelet counts should always be coupled to a panel of coagulation markers and not be used as single marker of DIC (or other syndromes). In general, thrombocytopenia should not trigger platelet transfusions except in patients with severe bleeding complications.

  18. [Coagulation-flocculation performances for cuttlefish effluents treatment].

    PubMed

    Ellouze, E; Amar, R B; Boufi, S; Salah, A B

    2003-11-01

    Coagulation-flocculation of the colloids particles present in the cuttlefish effluents was investigated using a coagulation step with aluminium sulphate (SA), followed by a flocculation step with starch, SiO2 or MgO and then poly dimethyl ammonium chloride (PDMAC), in order to reduce the turbidity and chemical oxygen demand (COD). Kinetic aspects, adsorption equilibrium, pH and conductivity were studied in order to determine the optimum coagulation conditions and SA quantities. The addition of organic polymer as a flocculant agent gave a better performance than the use of salt alone with a reduction of 50% of the SA consumption. Polymer molecular weight of PDMAC and charge density of starch have been also investigated. The best result, which is 90% of removal rate in chemical oxygen demand (COD) and a turbidity value of 7 NTU was obtained with the combination using 165.5 mg l(-1) of aluminium sulphate, 750 mg l(-1) of MgO and 35 mg l(-1) of PDMAC 400000.

  19. Inhibitors of propagation of coagulation: factors V and X

    PubMed Central

    Toschi, Vincenzo; Lettino, Maddalena

    2011-01-01

    Cardiovascular diseases are still the most important cause of morbidity and mortality in western countries and antithrombotic treatment is nowadays widely used. Drugs able to reduce coagulation activation are the treatment of choice for a number of arterial and/or venous thromboembolic conditions. Some of the drugs currently used for this purpose, such as heparins (UFH or LMWH) and VKA, have limitations consisting of a narrow therapeutic window and an unpredictable response with the need of laboratory monitoring in order to assess their efficacy and safety. These drawbacks have stimulated an active research aimed to develop new drugs able to act on single factors involved in the coagulation network, with predictable response. Intense experimental and clinical work on new drugs has focused on synthetic agents, which could preferably be administered orally and at fixed doses. The most advanced clinical development with new anticoagulants has been achieved for those inhibiting FXa and some of them, like fondaparinux, are already currently used in clinical practice. Other agents, such as rivaroxaban, apixaban, otamixaban and edoxaban are under development and have already been studied or are currently under investigation in large scale phase III clinical trials for prevention and treatment of venous thromboembolism, atrial fibrillation and acute coronary syndromes. Some of them have proved to be more effective than conventional therapy. Data on some agents inhibiting FVa are still preliminary and some of these drugs have so far been considered only in patients with disseminated intravascular coagulation secondary to sepsis. PMID:21545479

  20. Rennet-induced milk coagulation by continuous steady shear stress.

    PubMed

    Konuklar, Gül; Gunasekaran, Sundaram

    2002-06-01

    The effect of continuous steady shear stress (CSSS) on rennet-induced coagulation of milk was studied by measuring the change in viscosity of the system with time. Continuous shear stress (< or =0.5 Pa) applied during coagulation did not counteract the network formation at standard cheese-making conditions. In fact, CSSS of 0.2 Pa promoted coagulation by possibly increasing diffusion, collision, and hydrolization rates due to near-field, attractive hydrodynamic reactions. This was evidenced by the high viscosity of the resultant coagulum. However, the viscosity profile of the coagulum formed in the presence of CSSS followed the same trend as that formed in the absence of CSSS. Viscosity versus time profiles in both cases displayed an initial lag phase followed by a steady increase until a plateau value. The viscosity plateau reached under CSSS was marked with several sudden peaks, indicating the dynamic structure of the coagulum. These peaks in viscosity profiles began to appear after about 1380 s since rennet addition at standard cheese-making conditions. The time at which viscosity first exceeds 40 kPa s was verified to coincide with manual determination of the time at which the coagulum is cut (i.e., cutting time) during cheese making.

  1. Breaking boundaries—coagulation and fibrinolysis at the neurovascular interface

    PubMed Central

    Bardehle, Sophia; Rafalski, Victoria A.; Akassoglou, Katerina

    2015-01-01

    Blood proteins at the neurovascular unit (NVU) are emerging as important molecular determinants of communication between the brain and the immune system. Over the past two decades, roles for the plasminogen activation (PA)/plasmin system in fibrinolysis have been extended from peripheral dissolution of blood clots to the regulation of central nervous system (CNS) functions in physiology and disease. In this review, we discuss how fibrin and its proteolytic degradation affect neuroinflammatory, degenerative and repair processes. In particular, we focus on novel functions of fibrin—the final product of the coagulation cascade and the main substrate of plasmin—in the activation of immune responses and trafficking of immune cells into the brain. We also comment on the suitability of the coagulation and fibrinolytic systems as potential biomarkers and drug targets in diseases, such as multiple sclerosis (MS), Alzheimer’s disease (AD) and stroke. Studying coagulation and fibrinolysis as major molecular pathways that regulate cellular functions at the NVU has the potential to lead to the development of novel strategies for the detection and treatment of neurologic diseases. PMID:26441525

  2. Hereditary blood coagulation disorders: management and dental treatment.

    PubMed

    Gómez-Moreno, G; Cutando-Soriano, A; Arana, C; Scully, C

    2005-11-01

    Patients with hereditary hemostatic disorders, characterized by a tendency to bleeding or thrombosis, constitute a serious challenge in the dental practice. Advances in the medical diagnosis of hemostatic disorders have exposed dental professionals to new patients not amenable to the application of the management protocols associated with other, more well-known, disorders. It is the aim of this paper to review the evidence, to highlight the areas of major concern, and to suggest management regimens for patients with hereditary hemostatic disorders. An extensive review has been made (PubMed, Science Direct, Web of Knowledge, etc.) of literature pertaining to hereditary disorders affecting blood coagulation factors and how they affect the practice of dentistry. Several aspects relating to the care of such patients must be recognized and taken into consideration when dental treatment is planned. Replacement of deficient coagulation factors ensures that safe dental treatment will be carried out. However, the half-life of such coagulation factors requires that dental treatment be specifically planned and adapted to the type of pathology involved.

  3. Slaughterhouse wastewater treatment by combined chemical coagulation and electrocoagulation process.

    PubMed

    Bazrafshan, Edris; Kord Mostafapour, Ferdos; Farzadkia, Mehdi; Ownagh, Kamal Aldin; Mahvi, Amir Hossein

    2012-01-01

    Slaughterhouse wastewater contains various and high amounts of organic matter (e.g., proteins, blood, fat and lard). In order to produce an effluent suitable for stream discharge, chemical coagulation and electrocoagulation techniques have been particularly explored at the laboratory pilot scale for organic compounds removal from slaughterhouse effluent. The purpose of this work was to investigate the feasibility of treating cattle-slaughterhouse wastewater by combined chemical coagulation and electrocoagulation process to achieve the required standards. The influence of the operating variables such as coagulant dose, electrical potential and reaction time on the removal efficiencies of major pollutants was determined. The rate of removal of pollutants linearly increased with increasing doses of PACl and applied voltage. COD and BOD(5) removal of more than 99% was obtained by adding 100 mg/L PACl and applied voltage 40 V. The experiments demonstrated the effectiveness of chemical and electrochemical techniques for the treatment of slaughterhouse wastewaters. Consequently, combined processes are inferred to be superior to electrocoagulation alone for the removal of both organic and inorganic compounds from cattle-slaughterhouse wastewater.

  4. Inhibitory effect of ethinylestradiol on coagulation factors in rats

    PubMed Central

    Franco-Murillo, Yanira; Jaimez, Ruth

    2016-01-01

    Epidemiological and experimental data have indicated the beneficial and adverse effects of estrogenic replacement therapy. In the present study, we explored the effect of ethinylestradiol (EE) and 17β-estradiol (E2) on screening tests, prothrombin time (PT) and activated partial thromboplastin time (APTT), as well as the activity of coagulation factors (FVII, FX, FXI, and FXII) in male Wistar rats. Animals were injected subcutaneously during three consecutive days with EE or E2 (1, 3, 10, and 30 mg/kg) and propylene glycol (0.3 ml; vehicle, V). EE produced significant increments (P<0.05) on PT (8, 13, 15, and 10%) and APTT (32, 35, and 28%), whereas E2 did not show any effect. EE diminished the activity of factors VII (−10, −13, and −10%) and X (−10, −9, −15, and −14%; P<0.05), and E2 (1 mg/kg) produced a modest increment (8%; P<0.05) on FX only. E2 (10 mg/kg) showed a diminution of 9% (P<0.05), while EE did not produce any response on factor XII. EE diminished (−15, −14, −19, and −17%) but E2 augmented (10, 14, 24, and 24%) factor XI activity (P<0.05). Our findings suggest that EE and E2 produce different effects on coagulation and that EE seems to act across an inhibitory mechanism of coagulation factor activity in the present experimental model. PMID:27829580

  5. Tissue Factor, Blood Coagulation, and Beyond: An Overview

    PubMed Central

    Chu, Arthur J.

    2011-01-01

    Emerging evidence shows a broad spectrum of biological functions of tissue factor (TF). TF classical role in initiating the extrinsic blood coagulation and its direct thrombotic action in close relation to cardiovascular risks have long been established. TF overexpression/hypercoagulability often observed in many clinical conditions certainly expands its role in proinflammation, diabetes, obesity, cardiovascular diseases, angiogenesis, tumor metastasis, wound repairs, embryonic development, cell adhesion/migration, innate immunity, infection, pregnancy loss, and many others. This paper broadly covers seminal observations to discuss TF pathogenic roles in relation to diverse disease development or manifestation. Biochemically, extracellular TF signaling interfaced through protease-activated receptors (PARs) elicits cellular activation and inflammatory responses. TF diverse biological roles are associated with either coagulation-dependent or noncoagulation-mediated actions. Apparently, TF hypercoagulability refuels a coagulation-inflammation-thrombosis circuit in “autocrine” or “paracrine” fashions, which triggers a wide spectrum of pathophysiology. Accordingly, TF suppression, anticoagulation, PAR blockade, or general anti-inflammation offers an array of therapeutical benefits for easing diverse pathological conditions. PMID:21941675

  6. Crosstalk between inflammation and coagulation: the lessons of sepsis.

    PubMed

    van der Poll, Tom; Levi, Marcel

    2012-09-01

    Sepsis results in the concurrent activation of inflammatory and procoagulant pathways. Bacterial products and proinflammatory cytokines trigger the coagulation system primarily via induction of tissue factor. During sepsis, activation of coagulation is accompanied by impaired function of major anticoagulant mechanisms, including antithrombin, the protein C system and fibrinolysis. Protease activated receptors (PARs) form the molecular connection between coagulation and inflammation, and especially PAR1 seems to play an eminent role in sepsis pathogenesis. Activated protein C (APC) can cleave PAR1 when associated with either the endothelial protein C receptor (EPCR) or CD11b/CD18, resulting in broad cytoprotective effects mediated by sphingosine 1 phosphate (S1P) receptor 1 (S1P1). In contrast, activation of PAR1 by high dose thrombin results in barrier disruptive effects in endothelial cells via an S1P3 dependent mechanism. Recombinant APC protects against mortality in experimental endotoxemia and sepsis by effects that can be mediated by either EPCR - PAR1 dependent (endothelial cells, dendritic cells) or CD11b/CD18 - PAR1 dependent (macrophages) mechanisms. These protective APC effects do not rely on the anticoagulant properties of this protein. APC mutants that lack anticoagulant properties but retain the capacity to activate PAR1 are promising new drugs for sepsis treatment.

  7. Colon and pancreas tumors enhance coagulation: role of hemeoxygenase-1.

    PubMed

    Nielsen, Vance G; Nfonsam, Valentine N; Matika, Ryan W; Ong, Evan S; Jie, Tun; Warneke, James A; Steinbrenner, Evangelina B

    2014-07-01

    Colon and pancreatic cancer are associated with significant thrombophilia. Colon and pancreas tumor cells have an increase in hemeoxygenase-1 (HO-1) activity, the endogenous enzyme responsible for carbon monoxide production. Given that carbon monoxide enhances plasmatic coagulation, we determined if patients undergoing resection of colon and pancreatic tumors had an increase in endogenous carbon monoxide and plasmatic hypercoagulability. Patients with colon (n = 17) and pancreatic (n = 10) tumors were studied. Carbon monoxide was determined by the measurement of carboxyhemoglobin (COHb). A thrombelastographic method to assess plasma coagulation kinetics and formation of carboxyhemefibrinogen (COHF) was utilized. Nonsmoking patients with colon and pancreatic tumors had abnormally increased COHb concentrations of 1.4 ± 0.9 and 1.9 ± 0.7%, respectively, indicative of HO-1 upregulation. Coagulation analyses comparing both tumor groups demonstrated no significant differences in any parameter; thus the data were combined for the tumor groups for comparison with 95% confidence interval values obtained from normal individuals (n = 30) plasma. Seventy percent of tumor patients had a velocity of clot formation greater than the 95% confidence interval value of normal individuals, with 53% of this hypercoagulable group also having COHF formation. Further, 67% of tumor patients had clot strength that exceeded the normal 95% confidence interval value, and 56% of this subgroup had COHF formation. Finally, 63% of all tumor patients had COHF formation. Future investigation of HO-1-derived carbon monoxide in the pathogenesis of colon and pancreatic tumor-related thrombophilia is warranted.

  8. Factor VIII assay mimicking in vivo coagulation conditions.

    PubMed

    Kusch, M; Grundmann, C; Keitel, S; König, H

    2014-03-01

    Under certain circumstances, the determination of coagulation factor VIII (FVIII) is hampered by assay discrepancies between clotting and chromogenic approaches. These are observed in certain patients' plasma as well as in certain concentrates. We intended to develop a novel assay for the quantification of coagulation FVIII which reflects the physiological situation better than the established assays. It is based on plasma without chelation of divalent cations and simultaneously minimizes the generation of activated factors which could function as uncontrolled triggers of coagulation. FVIII deficient plasma is prepared with the aid of biotinylated antibodies against FVIII from normal plasma in presence of inhibitors of contact activation. To start the assay only tiny amounts of activated FIX serve as trigger. The FVIII determination is performed in a kinetic experiment and is based on the cleavage of a fluorogenic substrate for activated FX. FVIII concentrations between 0.01 and 1 IU mL(-1) are easily determined. Plasma-derived and recombinant FVIII concentrates were compared. All plasma-derived concentrates were found to contain FVIII activities within the specification of the manufacturer. Recombinant concentrates yielded only 35-50% of the claimed potency. The novel in vivo-like assay avoids the undue advantage or disadvantage of certain product characteristics by eliminating unphysiological assay conditions. Its usefulness could turn out in future experiments with plasma from haemophilia A patients. © 2013 John Wiley & Sons Ltd.

  9. Inhibitory effect of ethinylestradiol on coagulation factors in rats.

    PubMed

    Franco-Murillo, Yanira; Jaimez, Ruth

    2017-05-03

    Epidemiological and experimental data have indicated the beneficial and adverse effects of estrogenic replacement therapy. In the present study, we explored the effect of ethinylestradiol (EE) and 17β-estradiol (E2) on screening tests, prothrombin time (PT) and activated partial thromboplastin time (APTT), as well as the activity of coagulation factors (FVII, FX, FXI, and FXII) in male Wistar rats. Animals were injected subcutaneously during three consecutive days with EE or E2 (1, 3, 10, and 30 mg/kg) and propylene glycol (0.3 ml; vehicle, V). EE produced significant increments (P<0.05) on PT (8, 13, 15, and 10%) and APTT (32, 35, and 28%), whereas E2 did not show any effect. EE diminished the activity of factors VII (-10, -13, and -10%) and X (-10, -9, -15, and -14%; P<0.05), and E2 (1 mg/kg) produced a modest increment (8%; P<0.05) on FX only. E2 (10 mg/kg) showed a diminution of 9% (P<0.05), while EE did not produce any response on factor XII. EE diminished (-15, -14, -19, and -17%) but E2 augmented (10, 14, 24, and 24%) factor XI activity (P<0.05). Our findings suggest that EE and E2 produce different effects on coagulation and that EE seems to act across an inhibitory mechanism of coagulation factor activity in the present experimental model.

  10. [Preoperative monitoring of blood coagulation in urologic operations: diagnosis of familial factor XI deficiency within the scope of preoperative blood coagulation studies].

    PubMed

    Haushofer, A; Halbmayer, W M; Toth, E; Pflüger, H

    1993-01-01

    Presurgical coagulation diagnosis should--apart from coagulation monitoring in the laboratory based on a stepwise diagnosis for detection of coagulations disorders, starting with global tests (NT/APTT) followed by appropriate specific investigation in case of pathological findings--consist of an adequate hemostaseological anamnesis and physical checkup of the patient. This would allow detection of important signs of hemostaseological impairment during the pre-analytical phase already and permit subsequent initiation of more specific coagulation tests. The casuistics of a patient with factor XI-deficiency ("Minor Form"), a condition which is extremely infrequent in our country, demonstrates the coagulation diagnostic procedure which led to detection of his inherited factor XI-deficiency. In addition the pre-, peri- and postsurgical therapeutical management of this particular patient using an antifibrinolytic drug (tranexamic acid) is presented.

  11. Lighting: Green Light.

    ERIC Educational Resources Information Center

    Maniccia, Dorine

    2003-01-01

    Explains that by using sustainable (green) building practices, schools and universities can make their lighting systems more efficient, noting that embracing green design principles can help schools attract students. Discusses lighting-control technologies (occupancy sensing technology, daylighting technology, and scheduling based technologies),…

  12. Lighting: Green Light.

    ERIC Educational Resources Information Center

    Maniccia, Dorine

    2003-01-01

    Explains that by using sustainable (green) building practices, schools and universities can make their lighting systems more efficient, noting that embracing green design principles can help schools attract students. Discusses lighting-control technologies (occupancy sensing technology, daylighting technology, and scheduling based technologies),…

  13. Quarantine versus pathogen-reduced plasma-coagulation factor content and rotational thromboelastometry coagulation.

    PubMed

    Theusinger, Oliver M; Goslings, David; Studt, Jan-Dirk; Brand-Staufer, Brigitte; Seifert, Burkhardt; Spahn, Donat R; Frey, Beat M

    2017-03-01

    Different types of fresh-frozen plasma (FFP) exist, and the concentrations of plasma proteins vary between individuals and blood groups. Furthermore, processing may also influence the content. Quarantine-stored plasma (qFFP) and plasma that was pathogen-reduced using blood-safety (Intercept) technology (piFFP) were analyzed regarding procoagulant and anticoagulant hemostasis proteins, including endogenous thrombin (thrombin-generation) potential (ETP). Thirty-five samples of each type of FFP were analyzed using only male Blood Group O donors. FFP units were stored frozen for comparable periods of time before plasma protein content was assessed. Once the units were thawed, all tests were completed within 4 hours. The results are presented as means ± standard deviations or as median (minimum; maximum) and were compared using independent-sample t tests (significance, p < 0.01). Significantly higher concentrations of adintegrin-like and metalloprotease with thrombospondin type-13 motifs (ADAMTS13), fibrinogen, Factor (F)V, FVIII, FXIII, protein S, protein S activity, antithrombin, microvesicle (<900 nm), and α2 antiplasmin were observed in qFFP. The variability of factors was significantly lower in piFFP. Tissue factor (TF) at 1 picomolar (pM) exhibited significantly longer lag time, a lower peak, lower ETP, and a lower velocity index in qFFP compared with piFFP. In TF at 5 pM, significant differences in lag time (longer in qFFP), velocity index (lower in qFFP), and peak (lower in qFFP) were observed. Rotational thromboelastometry revealed a significantly longer (p = 0.002) clot-formation time with intrinsic thromboelastometry for piFFP and a significantly shorter clotting time (p = 0.004) with thromboelastometry fibrinogen testing for piFFP. Pathogen reduction reduces procoagulant and anticoagulant coagulation factors as well as variability. A thrombin-generation assay showed no reduced ETP and no supraphysiological thrombin generation. None of the

  14. Coagulation on biomaterials in flowing blood: some theoretical considerations.

    PubMed

    Basmadjian, D; Sefton, M V; Baldwin, S A

    1997-12-01

    Are truly inert biomaterials feasible? Recent mathematical models of coagulation which are reviewed here suggest that such materials are impossible. This conclusion, which is certainly consistent with our collective experimental evidence, arises from the calculation that conversion of Factor XI to XIa never drops to zero even at the highest flow rates and with virtually no Factor XIIa bound to a surface. Residual amounts of XIa are still formed which can in principle kick-off the coagulation cascade. Furthermore, if the flow rates and corresponding mass transfer coefficients are low and in spite of these near-vanishing levels of the initiating coagulants, the surprising result is that substantial amounts of thrombin are produced. On the contrary, under slightly higher flow conditions, there can be more substantial levels of initiating coagulants, yet paradoxically thrombin production is near zero. This article presents a theoretical understanding of the events which take place during the interaction of biomaterials with flowing blood. We follow these events from the time of first contact to the final production of thrombin. The effect of flow and surface activity on the contact phase reactions is examined in detail and the two are found to be intertwined. The common pathway is also examined and here the main feature is the existence of three flow dependent regions which produce either high or very low levels of thrombin, as well as multiple thrombin steady states. In a final analysis we link the two segments of the cascade and consider the events which result. In addition, we note that multiple steady states arise only in the presence of two (thrombin) feedback loops. Single loops or the bare cascade will produce only single steady states. With some imagination one can attribute to the feedback loops the role of providing the cascade with a mechanism to produce high thrombin levels in case of acute need (e.g. bleeding) or to allow levels to subside to 'stand

  15. Coagulation management in patients undergoing mechanical circulatory support.

    PubMed

    Görlinger, Klaus; Bergmann, Lars; Dirkmann, Daniel

    2012-06-01

    The incidence of bleeding and thrombo-embolic complications in patients undergoing mechanical circulatory support therapy remains high and is associated with bad outcomes and increased costs. The need for anticoagulation and anti-platelet therapy varies widely between different pulsatile and non-pulsatile ventricular-assist devices (VADs) and extracorporeal membrane oxygenation (ECMO) systems. Therefore, a unique anticoagulation protocol cannot be recommended. Notably, most thrombo-embolic complications occur despite values of conventional coagulation tests being within the targeted range. This is due to the fact that conventional coagulation tests such as international normalised ratio (INR), activated partial thromboplastin time (aPTT) and platelet count cannot detect hyper- or hypofibrinolysis, hypercoagulability due to tissue factor expression on circulating cells or increased clot firmness, and platelet aggregation as well as response to anti-platelet drugs. By contrast, point-of-care (POC) whole blood viscoelastic tests (thromboelastometry/-graphy) and platelet function tests (impedance or turbidimetric aggregometry) reflect in detail the haemostatic status of patients undergoing mechanical circulatory support therapy and the efficacy of their anticoagulation and antiaggregation therapy. Therefore, monitoring of haemostasis using POC thromboelastometry/-graphy and platelet function analysis is recommended during mechanical circulatory support therapy to reduce the risk of bleeding and thrombo-embolic complications. Notably, these haemostatic tests should be performed repeatedly during mechanical circulatory support therapy since thrombin generation, clot firmness and platelet response may change significantly over time with a high inter- and intra-individual variability. Furthermore, coagulation management can be hampered in non-pulsatile VADs by acquired von Willebrand syndrome, and in general by acquired factor XIII deficiency as well as by heparin

  16. Ocular hazards of light

    NASA Technical Reports Server (NTRS)

    Sliney, David H.

    1994-01-01

    The eye is protected against bright light by the natural aversion response to viewing bright light sources. The aversion response normally protects the eye against injury from viewing bright light sources such as the sun, arc lamps and welding arcs, since this aversion limits the duration of exposure to a fraction of a second (about 0.25 s). The principal retinal hazard resulting from viewing bright light sources is photoretinitis, e.g., solar retinitis with an accompanying scotoma which results from staring at the sun. Solar retinitis was once referred to as 'eclipse blindness' and associated 'retinal burn'. Only in recent years has it become clear that photoretinitis results from a photochemical injury mechanism following exposure of the retina to shorter wavelengths in the visible spectrum, i.e., violet and blue light. Prior to conclusive animal experiments at that time, it was thought to be a thermal injury mechanism. However, it has been shown conclusively that an intense exposure to short-wavelength light (hereafter referred to as 'blue light') can cause retinal injury. The product of the dose-rate and the exposure duration always must result in the same exposure dose (in joules-per-square centimeter at the retina) to produce a threshold injury. Blue-light retinal injury (photoretinitis) can result from viewing either an extremely bright light for a short time, or a less bright light for longer exposure periods. This characteristic of photochemical injury mechanisms is termed reciprocity and helps to distinguish these effects from thermal burns, where heat conduction requires a very intense exposure within seconds to cause a retinal coagulation otherwise, surrounding tissue conducts the heat away from the retinal image. Injury thresholds for acute injury in experimental animals for both corneal and retinal effects have been corroborated for the human eye from accident data. Occupational safety limits for exposure to UVR and bright light are based upon this

  17. Interference in coagulation testing: focus on spurious hemolysis, icterus, and lipemia.

    PubMed

    Lippi, Giuseppe; Plebani, Mario; Favaloro, Emmanuel J

    2013-04-01

    The chance that errors might jeopardize the quality of testing is inherently present throughout the total testing process, especially in the preanalytical phase. In the coagulation laboratory, as well as in other areas of diagnostic testing, spurious hemolysis, icteria, and lipemia in test samples represent by far the leading diagnostic challenges. Interference in hemostasis testing due to spurious hemolysis is attributed to both analytical and biologic elements, namely high absorbance of cell-free hemoglobin at wavelengths used by optical instrumentation and release of both cytoplasmatic and plasma membrane molecules (e.g., tissue factor, proteases, phospholipids, and ADP) that can spuriously activate blood coagulation and platelets. The interference attributable to hyperbilirubinemia is mostly due to spectral overlap, whereas that of hypertriglyceridemia mainly reflects elements of light scatter and volume displacement as well as direct interference of lipid particles with hemostasis. In practical terms, spurious hemolysis reflects a more generalized process of endothelial and blood cell damage, so that test results on spuriously hemolyzed specimens should be systematically suppressed. The bias attributable to hyperbilirubinemia is less significant using modern coagulometers equipped with dedicated wavelengths (i.e., with readings at 650 nm or above), so that test results in samples with a bilirubin concentration up to 20 mg/dL can still be analytically reliable. The interference observed in lipemic samples is most evident with readings using wavelengths lower than 500 nm and can hence be prevented with readings at 650 nm or above, and/or using higher dilutions of the test sample, or can be abated in high hypertriglyceridemic specimens (i.e., > 1,000 mg/dL) using high speed microcentrifugation or lipid extraction with organic solvents such as fluorine-chlorinated hydrocarbon, or lipid-clearing agents such as LipoClear (StatSpin Inc., Norwood, MA) and n-hexane.

  18. Influence of coagulation mechanisms on the residual aluminum--the roles of coagulant species and MW of organic matter.

    PubMed

    Jiao, Ruyuan; Xu, Hui; Xu, Weiying; Yang, Xiaofang; Wang, Dongsheng

    2015-06-15

    Aluminum (Al) based coagulants are widely used in coagulation process to enhance the removal of turbidity and dissolved substances in the drinking water treatment. However, it raised more concerns due to the increase of residual aluminum in treated water, which can cause even more issues. In this study, the effects of organic matter molecular weight and coagulants species on the concentration and aluminum distribution in residual aluminum were investigated. The residual aluminum concentration decreases as the organic matter (OM) molecular weight (MW) rises. Charge neutralization mechanism was found to be the most important factor that determines the residual aluminum concentration directly. Basically, higher Ala percentage leads to lower residual Al concentration at acidic conditions, and Alb/Alc plays an important role in controlling the residual Al concentration at neutral and alkaline condition. The flocs structures formed by charge neutralization mechanism will be more compact for the mid and high MW OM, and fractal dimension (Df) was important to reflect the dissolved residual aluminum rather than the flocs size. The total dissolved residual aluminum concentration of Al13 and Al30 was mainly contributed by the fractions with low and/or high MW, especially by the fraction with MW range of 0-1 kDa. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Stability, sterility, coagulation, and immunologic studies of salmon coagulation proteins with potential use for mammalian wound healing and cell engineering.

    PubMed

    Laidmäe, Ivo; McCormick, Margaret E; Herod, Julia L; Pastore, Jennifer J; Salum, Tiit; Sawyer, Evelyn S; Janmey, Paul A; Uibo, Raivo

    2006-12-01

    Fibrin sealants made by polymerization of fibrinogen activated by the protease thrombin have many applications in hemostasis and wound healing. In treatments of acute injury or surgical wounds, concentrated fibrin preparations mimic the initial matrix that normally prevents bleeding and acts as a scaffold for cells that initiate tissue repair. However risks of infectious disease, immunogenic reaction, and the high cost of purified human or other mammalian blood proteins limit widespread use of these materials. Purified coagulation proteins from Atlantic salmon represent a potentially safer, equally effective, and less costly alternative in part because of the low ambient temperature of these farmed animals and the absence of endogenous agents known to be infectious in mammalian hosts. This study reports rheologic measurements of lyophilized salmon fibrinogen and thrombin that demonstrate stability to prolonged storage and gamma irradiation sufficient to reduce viral loads by over five orders of magnitude. Coagulation and immunologic studies in rats and rabbits treated intraperitoneally with salmon fibrin show no deleterious effects on coagulation profiles and no cross reactivity with host fibrinogen or thrombin. The results support the potential of salmon fibrin as an alternative to mammalian proteins in clinical applications.

  20. Modeling rennet coagulation time and curd firmness of milk.

    PubMed

    Bittante, G

    2011-12-01

    Milk coagulation properties (MCP) are traditionally expressed using rennet coagulation time (RCT), time to curd firmness (CF) of 20 mm (k₂₀), and CF 30 min after enzyme addition (a₃₀) values, all of which are single-point measures taken from the output of computerized renneting meters, such as the Formagraph. Thus, traditional MCP use only some of the available information. Moreover, because of the worldwide spreading of breeds such as the Holstein-Friesian, characterized by late-coagulating milk, it happens often that some samples do not coagulate at all, that a₃₀ is strongly and negatively related to RCT, and that k₂₀ is not measurable. The aim of the present work was to model CF as a function of time (CF(t), mm) over a 30-min interval. The model tested was CFt CFP e= x (1−e(−kCF×(t−RCT)) where CF(P) (mm) is the potential asymptotical CF at an infinite time, k(CF) (min⁻¹) is the curd firming rate constant, and RCT is measured inminutes. The CF(t) model was initially applied to data of milk of each of 105 Brown Swiss cows from 7 herds, each sampled once (trial 1). Four samples did not coagulate within 30 min. Eighty-seven of the 101 individual equations obtained fit the CF data of milk samples very well, even though the samples differed in composition, and were produced by cows of different ages and days in milk, reared on different farms (coefficient of determination >0.99; average residual standard deviation=0.21 mm). Samples with a very late RCT (slowly coagulating samples) yielded so few observational data points that curve parameters could not be precisely estimated. The repeatability of CF(t) equation parameters was estimated using data obtained from 5 replicates of each of 2 samples of bulk milk from 5 Holstein-Friesian cows analyzed every day for 5 consecutive days (trial 2). Repeatability of RCT was better than that of the other 2 parameters. Moreover, traditional MCP values (RCT, a₃₀, and k₂₀) can be obtained from the

  1. Spatial localization of bacteria controls coagulation of human blood by 'quorum acting'.

    PubMed

    Kastrup, Christian J; Boedicker, James Q; Pomerantsev, Andrei P; Moayeri, Mahtab; Bian, Yao; Pompano, Rebecca R; Kline, Timothy R; Sylvestre, Patricia; Shen, Feng; Leppla, Stephen H; Tang, Wei-Jen; Ismagilov, Rustem F

    2008-12-01

    Blood coagulation often accompanies bacterial infections and sepsis and is generally accepted as a consequence of immune responses. Though many bacterial species can directly activate individual coagulation factors, they have not been shown to directly initiate the coagulation cascade that precedes clot formation. Here we demonstrated, using microfluidics and surface patterning, that the spatial localization of bacteria substantially affects coagulation of human and mouse blood and plasma. Bacillus cereus and Bacillus anthracis, the anthrax-causing pathogen, directly initiated coagulation of blood in minutes when bacterial cells were clustered. Coagulation of human blood by B. anthracis required secreted zinc metalloprotease InhA1, which activated prothrombin and factor X directly (not via factor XII or tissue factor pathways). We refer to this mechanism as 'quorum acting' to distinguish it from quorum sensing--it does not require a change in gene expression, it can be rapid and it can be independent of bacterium-to-bacterium communication.

  2. The heterogeneous coagulation and flocculation of brewery wastewater using carbon nanotubes.

    PubMed

    Simate, Geoffrey S; Iyuke, Sunny E; Ndlovu, Sehliselo; Heydenrych, Mike

    2012-03-15

    Coagulation and flocculation treatment processes play a central role in the way wastewater effluents are managed. Their primary function is particle removal that can impart colour to a water source, create turbidity, and/or retain bacterial and viral organisms. This study was carried out to investigate whether carbon nanotubes (CNTs) can be used as heterogeneous coagulants and/or flocculants in the pretreatment of brewery wastewater. A series of experiments were conducted in which the efficiencies of pristine and functionalised CNTs were compared with the efficiency of traditional ferric chloride in a coagulation/flocculation process. Turbidity and chemical oxygen demand (COD), including the zeta potential were used to monitor the progress of the coagulation/flocculation process. Both pristine and functionalised CNTs demonstrated the ability to successfully coagulate colloidal particles in the brewery wastewater. Overall, ferric chloride was found to be a more effective coagulant than both the pristine and functionalised CNTs. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Effects of magnetic ion-exchange resin addition during coagulation on floc properties and membrane filtration.

    PubMed

    Choi, Yang Hun; Kweon, Ji Hyang; Jeong, Young Mi; Kwon, Soonbuhm; Kim, Hyung-Soo

    2010-03-01

    The application of magnetic ion-exchange resin (MIEX) during chemical coagulation was investigated for the removal of organic matters responsible for fouling in membrane processes. Two different coagulants were used-polyaluminium chloride (PAC1) and polyaluminum chloride silicate (PACS). The MIEX addition during coagulation with both PAC1 and PACS considerably enhanced removal of dissolved organic carbon. Coagulation with MIEX treatment substantially removed all portions of natural organic matter (NOM), while the MIEX treatment alone effectively removed the hydrophobic and transphilic portions of NOM. The enhanced NOM removal by PAC1 coagulation with the addition of MIEX had positive effects on membrane flux at moderate transmembrane pressure conditions. However, the almost identical flux patterns were reported in the experiments of coagulation with PACS and PACS with MIEX addition. The results of the specific cake resistances indicated that the MIEX addition substantially decreased the resistances. The larger size distributions of PAC1 with MIEX corresponded well with the flux improvement.

  4. Using microfluidics to understand the effect of spatial distribution of tissue factor on blood coagulation.

    PubMed

    Shen, Feng; Kastrup, Christian J; Ismagilov, Rustem F

    2008-01-01

    Initiation of blood coagulation by tissue factor (TF) is a robust, highly regulated process. Both the spatial distribution of TF and the geometry of the vasculature may play important roles in regulating coagulation. As this review describes, microfluidic systems provide a unique opportunity for investigating the spatiotemporal dynamics of blood coagulation in vitro. Microfluidic systems with surfaces of phospholipid bilayers patterned with TF have been used to demonstrate experimentally the threshold responses of initiation of coagulation to the size and shape of surfaces presenting TF. These systems have also been used to demonstrate experimentally that propagation of coagulation is regulated by the shear rate of blood flow in microcapillaries and microchannels. By understanding these and other aspects of the spatial dynamics that regulate blood coagulation, many new methods for treating clotting disorders, such as venous thromboembolism (VTE) and sepsis, could arise.

  5. Evaluation of a coagulation/flocculation-lamellar clarifier and filtration-UV-chlorination reactor for removing emerging contaminants at full-scale wastewater treatment plants in Spain.

    PubMed

    Matamoros, Víctor; Salvadó, Victòria

    2013-03-15

    The presence and elimination of 25 emerging contaminants in two full-scale Spanish wastewater treatment plants was studied. The tertiary treatment systems consisted of coagulation, flocculation lamellar settlement and filtration (pulsed-bed sand filters) units, and disinfection was carried out by medium pressure UV light lamps and chlorination. Diclofenac and carbamazepine were found to be the emerging contaminants with the highest concentrations in secondary effluents. Photodegradable emerging contaminants (e.g. ketoprofen, triclosan and diclofenac) were removed by filtration-UV light radiation-chlorination whereas most hydrophobic compounds (e.g. galaxolide and tonalide) were eliminated by coagulation-flocculation followed by lamellar clarification, a unit in which a seasonal trend was observed. Overall mass removal efficiency was about 60%. 1-(8-Chlorocarbazolyl) acetic acid, an intermediate product of the photodegradation of diclofenac, was detected after filtration-UV-chlorination, but not after coagulation-flocculation and lamellar clarification. This study demonstrated potential for general applicability of two established tertiary treatment systems to eliminate emerging contaminants. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Application of low-mixing energy input for the coagulation process.

    PubMed

    Vadasarukkai, Yamuna S; Gagnon, Graham A

    2015-11-01

    Rapid-mixing tanks with mechanical mixers are a common design used in treatment plants. Yet, the role of such rapid-mixing systems on the effectiveness of the coagulation performance is unclear. This study looked at optimizing the direct energy used in the coagulation process for removal of natural dissolved organic matter (DOM). The role of coagulation mixing intensity (G-value) on total organic carbon (TOC) and turbidity removal was examined for the water types with high organic content, with a specific ultraviolet absorbance (SUVA) of at least 2-2.5 units of m(-1) of absorbance per mg/L. A standard jar test using ferric sulfate coagulant was performed to optimize the chemical condition in coagulation for removal of dissolved organics as well as particles. The jar test analysis at an acidic pH (4.5 ± 0.3) required an iron dose <0.3 mM to arrive at an optimal coagulant concentration and resulted in above 75% of TOC removal. The influence of coagulation mixing on TOC and turbidity removal was evaluated at G varying from 0 to 1500 s(-1) at the optimized coagulant dose and pH conditions for enhanced coagulation. In this study, a combined effective removal of TOC and turbidity was achieved at a low-mixing intensity range of 110 s(-1) < G < 450 s(-1). Coagulation operated at G greater than 450 s(-1) showed negligible improvement in TOC removal. Minimizing energy consumption in enhanced coagulation is feasible at the proposed mixing intensity range (i.e., 110 s(-1) < G < 450 s(-1)), without sacrificing the effectiveness of DOM removal by coagulation. These findings represent an opportunity for energy savings for the water industry without sacrificing quality. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Method of removing arsenic and other anionic contaminants from contaminated water using enhanced coagulation

    DOEpatents

    Teter, David M.; Brady, Patrick V.; Krumhansl, James L.; Khandaker, Nadim R.

    2006-11-21

    An improved water decontamination process comprising contacting water containing anionic contaminants with an enhanced coagulant to form an enhanced floc, which more efficiently binds anionic species (e.g., arsenate, arsenite, chromate, fluoride, selenate, and borate, and combinations thereof) predominantly through the formation of surface complexes. The enhanced coagulant comprises a trivalent metal cation coagulant (e.g., ferric chloride or aluminum sulfate) mixed with a divalent metal cation modifier (e.g., copper sulfate or zinc sulfate).

  8. Blood coagulation profiling in patients using optical thromboelastography (OTEG) (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Tripathi, Markandey M.; Tshikudi, Diane M.; Hajjarian, Zeinab; Van Cott, Elizabeth M.; Nadkarni, Seemantini K.

    2016-02-01

    Impaired blood coagulation is often associated with increased postoperative mortality and morbidity in cardiovascular patients. The capability for blood coagulation profiling rapidly at the bedside will enable the timely detection of coagulation defects and open the opportunity for tailoring therapy to correct specific coagulation deficits Optical Thromboelastography (OTEG), is an optical approach to quantify blood coagulation status within minutes using a few drops of whole blood. The goal of the current study is to evaluate the diagnostic accuracy of OTEG for rapid coagulation profiling in patients. In OTEG, temporal laser speckle intensity fluctuations from a drop of clotting blood are measured using a CMOS camera. To quantify coagulation status, the speckle intensity autocorrelation function is measured, the mean square displacement of scattering particles is extracted, and viscoelastic modulus (G), during coagulation is measured via the generalized Stokes-Einstein relation. By quantifying time-resolved changes in G, the coagulation parameters, reaction time (R), clot progression time (K), clot progression rate (Angle), and maximum clot strength (MA) are derived. In this study, the above coagulation parameters were measured using OTEG in 269 patients and compared with standard mechanical Thromboelastography (TEG). Our results showed a strong correlation between OTEG and TEG measurements for all parameters: R-time (R=0.80, p<0.001), clotting time (R=0.78, p<0.001), Angle (R=0.58, p<0.001), and MA (R=0.60, p<0.001). These results demonstrate the unique capability of OTEG for rapid quantification of blood coagulation status to potentially improve clinical capability for identifying impaired coagulation in cardiovascular patients at the point of care.

  9. Coagulant Recovery from Water Treatment Residuals: A Review of Applicable Technologies

    PubMed Central

    Keeley, J.; Jarvis, P.; Judd, S. J.

    2014-01-01

    Conventional water treatment consumes large quantities of coagulant and produces even greater volumes of sludge. Coagulant recovery (CR) presents an opportunity to reduce both the sludge quantities and the costs they incur, by regenerating and purifying coagulant before reuse. Recovery and purification must satisfy stringent potable regulations for harmful contaminants, while remaining competitive with commercial coagulants. These challenges have restricted uptake and lead research towards lower-gain, lower-risk alternatives. This review documents the context in which CR must be considered, before comparing the relative efficacies and bottlenecks of potential technologies, expediting identification of the major knowledge gaps and future research requirements. PMID:26064036

  10. Removal of natural organic matter in drinking water treatment by coagulation: A comprehensive review.

    PubMed

    Sillanpää, Mika; Ncibi, Mohamed Chaker; Matilainen, Anu; Vepsäläinen, Mikko

    2017-09-25

    Natural organic matter (NOM) is a complex matrix of organic substances produced in (or channeled to) aquatic ecosystems via various biological, geological and hydrological cycles. Such variability is posing a serious challenge to most water treatment technologies, especially the ones designed to treat drinking water supplies. Lately, in addition to the fluctuating composition of NOM, a substantial increase of its concentration in fresh waters, and also municipal wastewater effluents, has been reported worldwide, which justifies the urgent need to develop highly efficient and versatile water treatment processes. Coagulation is among the most applied processes for water and wastewater treatment. The application of coagulation to remove NOM from drinking water supplies has received a great deal of attention from researchers around the world because it was efficient and helped avoiding the formation of disinfection by products (DBPs). Nonetheless, with the increased fluctuation of NOM in water (concentration and composition), the efficiency of conventional coagulation was substantially reduced, hence the need to develop enhanced coagulation processes by optimizing the operating conditions (mainly the amount coagulants and pH), developing more efficient inorganic or organic coagulants, as well as coupling coagulation with other water treatment technologies. In the present review, recent research studies dealing with the application of coagulation for NOM removal from drinking water supplies are presented and compared. In addition, integration schemes combining coagulation and other water treatment processes are presented, including membrane filtration, oxidation, adsorption and others processes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Aerosol coagulation in the plume from a cross-wind line source

    NASA Astrophysics Data System (ADS)

    Tsang, T. H.; Brock, J. R.

    Various numerical schemes for approximating advection, diffusion and aerosol coagulation have been tested for the plume from a cross-wind line aerosol source. On the basis of these tests, it is concluded that Fromm's method for advection and orthogonal collocation on finite elements for diffusion are among the best means currently available. For numerical simulation of coagulation in a plume from a cross-wind line source, cubic spline interpolation and quadrature are very accurate in conserving aerosol mass concentration. Also, the numerical results for coagulation provide proof of the capability of the method of fractional steps to simulate accurately aerosol coagulation and transport.

  12. Development of a User-Friendly App for Testing Blood Coagulation Status in Schizophrenia Patients.

    PubMed

    Vegt, Johannes; Guest, Paul C

    2017-01-01

    Blood coagulation time is an important factor to consider for postoperative and cardiac disorder patients who have been prescribed anticoagulant coagulant medications. The coagulation process is also known to be perturbed in some individuals with psychiatric disorders, such as schizophrenia. This chapter describes a patient self-management system for a functional assessment of blood coagulation activity, determining the appropriate anticoagulant dosages using a test strip device and the Coagu app. The app can also be used as a patient reminder of treatment times and to monitor treatment and effects over time.

  13. A comprehensive study of ovine haemostasis to assess suitability to model human coagulation.

    PubMed

    Foley, Samuel R; Solano, Connie; Simonova, Gabriela; Spanevello, Michelle M; Bird, Robert J; Semple, John W; Jackson, Denise E; Schibler, Andreas; Fraser, John F; Fung, Yoke Lin

    2014-08-01

    Similarities in size, anatomy and physiology have supported the use of sheep to model a wide range of human diseases, including coagulopathy. However, coagulation studies involving sheep are limited by the absence of high quality data defining normal ovine coagulation and fibrinolysis. Full blood examination, routine and specialised coagulation tests, rotational thromboelastometry and whole blood platelet aggregometry was performed on 50 healthy Samm & Border Leicester Cross ewes and compared to corresponding human ranges. Intraspecies breed and gender variability was investigated by comparison to a smaller population of 13 healthy Merino wethers. Ovine coagulation was similar to human according to routine coagulation methods (PT, aPTT, TCT, Fib(C)) and some specialised coagulation tests (vWF, AT, Plasmin Inh). Despite these similarities, ovine secondary haemostasis demonstrated substantial differences to that of human. Rapid initiation of the contact activation pathway, high levels of FVIII, low Protein C, greater overall clot firmness and a reduced capacity for clot lysis was documented in sheep. In addition, ADP and collagen agonists precipitated a reduced primary haemostatic response in sheep relative to human. Intraspecies differences in whole blood platelet aggregometry between the cohorts of sheep indicate the need for breed-specific normal ranges. The application of a board spectrum of coagulation assays has enabled elucidation of the similarities as well as differences between ovine and human coagulation. The new knowledge generated from this study will guide the design of future translational coagulation studies in ovine models. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Arsenic removal from high-arsenic water by enhanced coagulation with ferric ions and coarse calcite.

    PubMed

    Song, S; Lopez-Valdivieso, A; Hernandez-Campos, D J; Peng, C; Monroy-Fernandez, M G; Razo-Soto, I

    2006-01-01

    Arsenic removal from high-arsenic water in a mine drainage system has been studied through an enhanced coagulation process with ferric ions and coarse calcite (38-74 microm) in this work. The experimental results have shown that arsenic-borne coagulates produced by coagulation with ferric ions alone were very fine, so micro-filtration (membrane as filter medium) was needed to remove the coagulates from water. In the presence of coarse calcite, small arsenic-borne coagulates coated on coarse calcite surfaces, leading the settling rate of the coagulates to considerably increase. The enhanced coagulation followed by conventional filtration (filter paper as filter medium) achieved a very high arsenic removal (over 99%) from high-arsenic water (5mg/l arsenic concentration), producing a cleaned water with the residual arsenic concentration of 13 microg/l. It has been found that the mechanism by which coarse calcite enhanced the coagulation of high-arsenic water might be due to attractive electrical double layer interaction between small arsenic-borne coagulates and calcite particles, which leads to non-existence of a potential energy barrier between the heterogeneous particles.

  15. Effect of the dosage ratio and the viscosity of PAC/PDMDAAC on coagulation performance and membrane fouling in a hybrid coagulation-ultrafiltration process.

    PubMed

    Shen, Xue; Gao, Baoyu; Huang, Xin; Bu, Fan; Yue, Qinyan; Li, Ruihua; Jin, Bo

    2017-04-01

    This study systematically determined the optimal dosage ratio and the viscosity (η) of co-coagulants, polyaluminum chloride (PAC) and poly dimethyldiallylammonium chloride (PDMDAAC), on coagulation performance and membrane fouling in a hybrid coagulation-ultrafiltration (C-UF) process for natural organic matter (NOM) removal. Floc characteristics-including floc size, fractal dimension, strength and re-growth ability-were studied with respect to coagulant-dosing operations. Membrane fouling was evaluated in association with assessment of NOM removal performance by the hybrid process. The best coagulation performance was achieved when PAC and PDMDAAC were dosed with 1.0 mg/L and 0.1 mg/L, respectively. The addition of PDMDAAC could enhance the NOM removal efficiency, especially at low PAC dosages. Co-coagulants PAC/PDMDAAC (ηPDMDAAC = 2.18 dL/g) resulted in formation of the largest flocs with the smallest Df under all shear conditions, while the flocs formed by PAC/PDMDAAC (ηPDMDAAC = 1.86 dL/g) had higher recovery abilities. The results from ultrafiltration experiments indicated that coagulation using PAC/PDMDAAC with a viscosity range from 0.99 dL/g to 1.86 dL/g can significantly reduce membrane fouling, leading to increasing water fluxes from 0.1170 to 0.4906 in the ultrafiltration process.

  16. Interaction of ultraviolet laser light with the cornea

    SciTech Connect

    Krueger, R.R.; Trokel, S.L.; Schubert, H.D.

    1985-11-01

    The effect of pulsed ultraviolet (UV) laser light on the cornea depends on wavelength (photon energy), irradiance (photon flux), and pulse firing rate. At the available excimer laser wavelengths of 193, 249, 308, and 351 nanometers, the authors have varied the irradiance per pulse (10 to 2000 mj/cmS) as well a pulse frequency (1, 10, 25 Hz) and determined the thresholds for coagulation and ablation of the corneal stroma. The latter ablative action creates a groove resembling an incision and was present at all wavelengths studied. The threshold for ablation increased for longer wavelengths and lower pulse frequencies, except for 193-nm exposure, which was characterized by a constant threshold independent of laser pulse rate. The grooves at 193 nm were both biomicroscopically and histologically smooth and no coagulation effects were noted. Some degree of coagulation of adjacent tissues was noted at 249, 308, and 351 nm.

  17. The effects of chemical coagulants on the decolorization of dyes by electrocoagulation using response surface methodology (RSM)

    NASA Astrophysics Data System (ADS)

    Butler, Erick B.; Hung, Yung-Tse; Mulamba, Oliver

    2016-04-01

    This study assessed the efficiency of electrocoagulation (ECF) coupled with an addition of chemical coagulant to decolorize textile dye. Tests were conducted using Box Behnken methodology to vary six parameters: dye type, weight, coagulant type, dose, initial pH and current density. The combination of electrocoagulation and chemical coagulation was able to decolorize dye up to 99.42 % in 30 min of treatment time which is remarkably shorter in comparison with using conventional chemical coagulation. High color removal was found to be contingent upon the dye type and current density, along with the interactions between the current density and the coagulant dose. The addition of chemical coagulants did enhanced treatment efficiency.

  18. The effects of chemical coagulants on the decolorization of dyes by electrocoagulation using response surface methodology (RSM)

    NASA Astrophysics Data System (ADS)

    Butler, Erick B.; Hung, Yung-Tse; Mulamba, Oliver

    2017-09-01

    This study assessed the efficiency of electrocoagulation (ECF) coupled with an addition of chemical coagulant to decolorize textile dye. Tests were conducted using Box Behnken methodology to vary six parameters: dye type, weight, coagulant type, dose, initial pH and current density. The combination of electrocoagulation and chemical coagulation was able to decolorize dye up to 99.42 % in 30 min of treatment time which is remarkably shorter in comparison with using conventional chemical coagulation. High color removal was found to be contingent upon the dye type and current density, along with the interactions between the current density and the coagulant dose. The addition of chemical coagulants did enhanced treatment efficiency.

  19. Coagulation Gene Expression Profiling in Infants With Necrotizing Enterocolitis.

    PubMed

    Giuliani, Stefano; Tan, Yew-Wei; Zheng, Dongling; Petropoulou, Evmorfia; Sohail, Ali; Bradley, Sarah; Richards, Justin; Kennea, Nigel; Jamshidi, Yalda

    2016-12-01

    Coagulopathy and mesenteric thrombosis are common in premature neonates with necrotizing enterocolitis (NEC). This pilot study aimed to investigate the hypothesis that there are changes in the gene expression related to the coagulation and anticoagulation systems in NEC. Consecutive neonates (n = 11) with NEC (Bell stages 2-3) were recruited. Two comparison groups, matched for birth weight and corrected gestational age, were selected based on the absence of inflammation and coagulopathy (healthy control, n = 10), or the presence of a confirmed blood infection (sepsis control, n = 12). A pathway-specific quantitative polymerase chain reaction array was used to determine the expression of 94 genes involved in human blood coagulation and anticoagulation cascade. Twelve genes of the coagulation and anticoagulation systems were significantly altered in the patients with NEC compared with healthy controls. In particular, neutrophil elastase, CD63, PROS1, HGF, and F12 were significantly upregulated (mean fold changes [FCs] +2.74, P < 0.05) with an overall procoagulant effect; MFGE8, factor II (thrombin) receptor-like 1 (F2RL1), FGL2, PLAT, PROCR, SERPIND1, and HNF4A were significantly downregulated (mean FCs -2.45, P < 0.05) with a reduction in fibrinolysis and endothelial regeneration. In the comparison between NEC and sepsis, we did observe a significant difference in expression of F2RL1 (FC -2.50, P = 0.01). We have identified potential biomarkers associated with coagulopathy and disease progression in NEC. In particular, the overall procoagulant status, at the transcriptional level, should be further investigated to unveil molecular mechanisms leading to intestinal necrosis, multiorgan failure, and death.

  20. Bloodcurdling movies and measures of coagulation: Fear Factor crossover trial

    PubMed Central

    Nemeth, Banne; Scheres, Luuk J J; Lijfering, Willem M

    2015-01-01

    Objective To assess whether, as has been hypothesised since medieval times, acute fear can curdle blood. Design Crossover trial. Setting Main meeting room of Leiden University’s Department of Clinical Epidemiology, the Netherlands, converted to a makeshift cinema. Participants 24 healthy volunteers aged ≤30 years recruited among students, alumni, and employees of the Leiden University Medical Center: 14 were assigned to watch a frightening (horror) movie followed by a non-threatening (educational) movie and 10 to watch the movies in reverse order. The movies were viewed more than a week apart at the same time of day and both lasted approximately 90 minutes. Main outcome measures The primary outcome measures were markers, or “fear factors” of coagulation activity: blood coagulant factor VIII, D-dimer, thrombin-antithrombin complexes, and prothrombin fragments 1+2. The secondary outcome was participant reported fear experienced during each movie using a visual analogue fear scale. Results All participants completed the study. The horror movie was perceived to be more frightening than the educational movie on a visual analogue fear scale (mean difference 5.4, 95% confidence interval 4.7 to 6.1). The difference in factor VIII levels before and after watching the movies was higher for the horror movie than for the educational movie (mean difference of differences 11.1 IU/dL (111 IU/L), 95% confidence interval 1.2 to 21.0 IU/dL). The effect of either movie on levels of thrombin-antithrombin complexes, D-dimer, and prothrombin fragments 1+2 did not differ. Conclusion Frightening (in this case, horror) movies are associated with an increase of blood coagulant factor VIII without actual thrombin formation in young and healthy adults. Trial registration ClinicalTrials.gov NCT02601053. PMID:26673787

  1. [Clinical diagnosis of thrombosis and blood coagulation tests].

    PubMed

    Watanabe, K

    1998-03-01

    Blood coagulation tests are useful to diagnose some thrombotic diseases. Particularly, these tests are valuable for the diagnosis of familiar thrombophilia, antiphospholipid antibody syndrome (APS) and disseminated intravascular coagulation (DIC). For the diagnosis of thrombophilia, determinations of both biological activity and antigen level of antithrombin III, protein C and protein S are important for initial screening. Since activated protein C (APC) resistance is extremely rare in Japanese, APC resistant test that based on APTT, is unnecessary to include as one of the screening tests. Detection of activity and antigen level of either plasminogen or fibrinogen is recommended to screen the plasminogen deficiency or dysfibrinogenemia. Determination of lupus anticoagulant is needed for the diagnosis of APS. At this time, the dilute phospholipid APTT (dAPTT) or the dilute Russell viper venom time (dRVVT) may be useful as a screening test for LA because procedure of these tests are basically simple to perform in Japanese laboratory. In the next step, cross mixing test of dAPTT (or APTT) should be perform to make a diagnose of LA more solid. Final confirm tests can be conveniently carried out with kit of either STACLOT or LA-CONFIRM. Platelet count and FDP (or FDP D dimer) assay are two essential tests for the diagnosis of DIC. Criteria of diagnosis for DIC recommended by Blood Coagulation Research Group of Japanese Ministry of Health and Welfare is not unnecessarily appropriate for practical use. TAT and PIC can be a good laboratory tests for early detection of hypercoagulable state in patients with DIC.

  2. Bloodcurdling movies and measures of coagulation: Fear Factor crossover trial.

    PubMed

    Nemeth, Banne; Scheres, Luuk J J; Lijfering, Willem M; Rosendaal, Frits R

    2015-12-16

    To assess whether, as has been hypothesised since medieval times, acute fear can curdle blood. Crossover trial. Main meeting room of Leiden University's Department of Clinical Epidemiology, the Netherlands, converted to a makeshift cinema. 24 healthy volunteers aged ≤30 years recruited among students, alumni, and employees of the Leiden University Medical Center: 14 were assigned to watch a frightening (horror) movie followed by a non-threatening (educational) movie and 10 to watch the movies in reverse order. The movies were viewed more than a week apart at the same time of day and both lasted approximately 90 minutes. The primary outcome measures were markers, or "fear factors" of coagulation activity: blood coagulant factor VIII, D-dimer, thrombin-antithrombin complexes, and prothrombin fragments 1+2. The secondary outcome was participant reported fear experienced during each movie using a visual analogue fear scale. All participants completed the study. The horror movie was perceived to be more frightening than the educational movie on a visual analogue fear scale (mean difference 5.4, 95% confidence interval 4.7 to 6.1). The difference in factor VIII levels before and after watching the movies was higher for the horror movie than for the educational movie (mean difference of differences 11.1 IU/dL (111 IU/L), 95% confidence interval 1.2 to 21.0 IU/dL). The effect of either movie on levels of thrombin-antithrombin complexes, D-dimer, and prothrombin fragments 1+2 did not differ. Frightening (in this case, horror) movies are associated with an increase of blood coagulant factor VIII without actual thrombin formation in young and healthy adults. Trial registration ClinicalTrials.gov NCT02601053. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  3. Effects of saline or albumin resuscitation on standard coagulation tests.

    PubMed

    Bellomo, Rinaldo; Morimatsu, Hiroshi; Presneill, Jeff; French, Craig; Cole, Louise; Story, David; Uchino, Shigehiko; Naka, Toshio; Finfer, Simon; Cooper, D James; Myburgh, John

    2009-12-01

    To explore whether fluid resuscitation with normal saline or 4% albumin is associated with differential changes in routine clinical coagulation tests. Substudy from a large double-blind randomised controlled trial, the SAFE (Saline versus Albumin Fluid Evaluation) study. Three general intensive care units. Cohort of 687 critically ill patients. We randomly allocated patients to receive either 4% human albumin or normal saline for fluid resuscitation, and collected demographic and haematological data. Albumin was administered to 338 patients and saline to 349. At baseline, the two groups had similar mean activated partial thromboplastin time (APTT) of 37.2 s (albumin) v 39.1 s (saline); mean international normalised ratio (INR) of 1.38 v 1.34, and mean platelet count of 244 x 10(9)/L v 249 x 10(9)/L. After randomisation, during the first day of treatment, the APTT in the albumin group was prolonged by a mean of 2.7 s, but shortened slightly by a mean of -0.9 s in the saline group. The INR did not change in either group, while the platelet count decreased transiently in both groups. Using multivariate analysis of covariance to account for baseline coagulation status, albumin fluid resuscitation (P = 0.01) and a greater overall volume of resuscitation (P = 0.03) were independently associated with prolongation of APTT during the first day. Administration of albumin or of larger fluid volumes is associated with a prolongation of APTT. In ICU patients, the choice and amount of resuscitation fluid may affect a routinely used coagulation test.

  4. Neprilysin Inhibits Coagulation through Proteolytic Inactivation of Fibrinogen

    PubMed Central

    Burrell, Matthew; Henderson, Simon J.; Ravnefjord, Anna; Schweikart, Fritz; Fowler, Susan B.; Witt, Susanne; Hansson, Kenny M.; Webster, Carl I.

    2016-01-01

    Neprilysin (NEP) is an endogenous protease that degrades a wide range of peptides including amyloid beta (Aβ), the main pathological component of Alzheimer’s disease (AD). We have engineered NEP as a potential therapeutic for AD but found in pre-clinical safety testing that this variant increased prothrombin time (PT) and activated partial thromboplastin time (APTT). The objective of the current study was to investigate the effect of wild type NEP and the engineered variant on coagulation and define the mechanism by which this effect is mediated. PT and APTT were measured in cynomolgus monkeys and rats dosed with a human serum albumin fusion with an engineered variant of NEP (HSA-NEPv) as well as in control plasma spiked with wild type or variant enzyme. The coagulation factor targeted by NEP was determined using in vitro prothrombinase, calibrated automated thrombogram (CAT) and fibrin formation assays as well as N-terminal sequencing of fibrinogen treated with the enzyme. We demonstrate that HSA-NEP wild type and HSA-NEPv unexpectedly impaired coagulation, increasing PT and APTT in plasma samples and abolishing fibrin formation from fibrinogen. This effect was mediated through cleavage of the N-termini of the Aα- and Bβ-chains of fibrinogen thereby significantly impairing initiation of fibrin formation by thrombin. Fibrinogen has therefore been identified for the first time as a substrate for NEP wild type suggesting that the enzyme may have a role in regulating fibrin formation. Reductions in NEP levels observed in AD and cerebral amyloid angiopathy may contribute to neurovascular degeneration observed in these conditions. PMID:27437944

  5. Optical changes of porcine brain tissue after thermal coagulation

    NASA Astrophysics Data System (ADS)

    Schwarzmaier, Hans-Joachim; Goldbach, Thomas; Yaroslavsky, Ilya V.; Ulrich, Frank; Bettag, Martin; Kahn, Thomas; Kaufmann, Raimund

    1995-05-01

    Porcine brain tissue is a model for human brain structures in laser induced thermo-therapy. However, its optical properties including possible heat-related changes were basically unknown so far. To simulate laser coagulation, 12 specimens (6 grey and 6 white matter) were heated in a saline bath (80°C, 2 hours) and compared to 11 untreated samples (5 grey and 6 white matter). The optical constants were obtained from transmission (total and collimated) and reflection (diffuse) measurements using the inverse Monte-Carlo method. The absorption coefficient ((mu) a) of untreated grey substance decreased from 0.35 +/- 0.06/mm (340 nm) to 0.03 +/- 0.02/mm (800 nm). The scattering coefficient ((mu) s) varied between 20.42 +/- 3.65/mm (340 nm) and 6.85 +/- 2.07/mm (800 nm). The anisotropy factor (g) increased from 0.848 +/- 0.013 (340 nm) to 0.889 +/- 0.009 (800 nm). Coagulation increased (mu) a up to a factor of 2 (340-540 nm; p < 0.05), and (mu) s by a factor up to 3 (340-800 nm, all data p < 0.001) while g was decreased up to 18% (340-560 nm; p < 0.05). White substance exhibited a (mu) a between 0.24 +/- 0.07/mm (340 nm) and 0.04 +/- 0.02/mm (800 nm) while (mu) s varied between 26.72 +/- 9.10/mm (340 nm) and 21.78 +/- 3.88/mm (800 nm). The g-value increased from 0.561 +/- 0.180 (340 nm) to 0.834 +/- 0.068 (800 nm). Coagulation increased (mu) a by a factor up to 2 (340-800 nm; all data p < 0.05) while (mu) s and g remained unchanged. Thermal denaturation changes the absorption and scattering properties of porcine brain significantly.

  6. Quantitative evaluation of hypothermia, hyperthermia, and hemodilution on coagulation.

    PubMed

    Kmiecik, S A; Liu, J L; Vaadia, T S; Nichols, J D; Kohtz, R J; Mills, N J; Petterson, C M; Stammers, A H

    2001-05-01

    The purpose of this study was to investigate the effects of temperature change on the coagulation time of blood at two different hematocrit levels by using various coagulation-monitoring devices. The devices used in this study were the Bayer Rapid Point Coag Analyzers, Hemochron Jr. Signature, Hemochron Response, Medtronic ACT II, and Haemoscope Thrombelastograph. One unit of human bank blood was used in this study. The hematocrit level was adjusted to 40% and 20%. A control bath and experimental bath were set up. Control blood was maintained at 37 degrees C and tested every 45 +/- 15 min throughout the experimental period of 6 h to demonstrate the stability of the model. The experimental blood was tested at temperature points of 37, 32, 27, 32, 37, 42, and 37 degrees C. Activated clotting time (ACT) tended to increase when the temperature was initially decreased from 37 to 27 degrees C, which reached a statistically significant level when measured by the Hemochron Response at both the 20% (147 +/- 10.7 to 159.3 +/- 11.0, p < .0332) and 40% hematocrit level (130 +/- 14.9 to 152.1 +/- 19.7, p < .0148). ACT was decreased significantly (p < .05) when the temperature was increased to 42 degrees C as measured by all machines except the Hemochron Jr. Signature at the 20% hematocrit level. ACT was significantly higher (p < .05) at a 20% hematocrit level as compared to that at a 40% hematocrit level on all devices for the majority of temperature points. These data suggested that hypothermia only increased ACT when measured by a macrosample device requiring a milliliter sample (Hemochron Response). However, hemodilution induced anticoagulatory effects and hyperthermia caused an acceleration in coagulation by all devices utilized in this study.

  7. Effect of remote ischaemic conditioning on coagulation and fibrinolysis.

    PubMed

    Kristiansen, Jacobina; Grove, Erik L; Rise, Nina; Neergaard-Petersen, Søs; Würtz, Morten; Kristensen, Steen Dalby; Hvas, Anne-Mette

    2016-05-01

    Remote ischaemic conditioning (RIC) reduces infarct size and may improve prognosis in patients with acute myocardial infarction. To explore the potential mechanisms, we investigated the effects of RIC on coagulation and fibrinolysis. Interventional crossover study including 30 healthy drug-naïve males. Participants were exposed to a sham intervention (visit 1) and to RIC (visit 2 and 3) induced by intermittent arm ischaemia through four cycles of 5-min inflation of a blood pressure cuff followed by 5-min deflation. Prior to visit 3, all participants received aspirin 75mg daily for seven days. Blood samples were obtained at baseline as well as 5 and 45min after intervention. Whole blood coagulation was assessed by thromboelastometry (ROTEM®) and thrombin generation. Fibrinolysis was evaluated by clot turbidity-lysis, tissue plasminogen activator (t-PA), and plasminogen activator inhibitor-1 (PAI-1). No differences were found in clot initiation, clot propagation or clot strength evaluated by ROTEM® (all p-values≥0.98). During aspirin treatment, clot initiation and clot propagation decreased after RIC evaluated by ROTEM® EXTEM® clotting time (p=0.04) and ROTEM® EXTEM® maximum velocity (p=0.03). After sham and RIC, thrombin generation declined as evaluated by reduced endogenous thrombin potential (RIC: p=0.001) and peak (RIC: p=0.01). After RIC during aspirin treatment, changes in thrombin generation were inconsistent; increased peak (p=0.04) and time to peak (p<0.001) and a decrease in lag-time (p<0.001). Clot lysis time was prolonged both after sham and after RIC (p<0.001). After RIC, PAI-1 levels declined (p=0.03), but t-PA levels also declined after all interventions (p-values≤0.04). RIC did not have substantial effects on coagulation or fibrinolysis compared to sham. Overall, aspirin did not influence the results. Copyright © 2016. Published by Elsevier Ltd.

  8. Update on anti-coagulation in atrial fibrillation

    PubMed Central

    2011-01-01

    Atrial fibrillation (AF), the most common clinically relevant arrhythmia, affects 2.2 million individuals in the USA and 4.5 million in Europe, resulting in significant morbidity and mortality. Pharmacotherapy aimed at controlling both heart rate and rhythm is employed to relieve AF symptoms, though debate continues about which approach is preferable. AF prevalence rises with age from 0.4% to 1% in the general population to 11% in those aged >70 years. AF is associated with a pro-thrombotic state and other comorbidities; age, hypertension, heart failure and diabetes mellitus all play a key role in AF pathogenesis. Anti-coagulation is essential for stroke prevention in patients with AF and is recommended for patients with one or more risk factors for stroke. Used within the recommended therapeutic range, warfarin and other vitamin K antagonists decrease the incidence of stroke and mortality in AF patients. Warfarin remains under-used, however, because of the perceived high risk of haemorrhage, narrow therapeutic window and need for regular monitoring. Several novel anti-coagulants show promise in AF-related stroke prevention. In particular, the novel, oral, direct thrombin inhibitor, dabigatran etexilate, recently licensed by the US Food and Drug Administration (FDA) and Health Canada has shown improved efficacy and safety compared with warfarin for stroke prevention in AF, and has the potential to replace warfarin in this indication. The increasing number of new therapeutic options, including improved anti-arrhythmic agents, novel anti-coagulants and more accessible ablation techniques, are likely to deliver better care for AF patients in the near future. PMID:21816811

  9. Altered blood coagulation in patients with posttraumatic stress disorder.

    PubMed

    von Känel, Roland; Hepp, Urs; Buddeberg, Claus; Keel, Marius; Mica, Ladislav; Aschbacher, Kirstin; Schnyder, Ulrich

    2006-01-01

    Posttraumatic stress disorder (PTSD) has been associated with an increased cardiovascular risk, though the pathophysiologic mechanisms involved are elusive. A hypercoagulable state before occurrence of coronary thrombosis contributes to atherosclerosis development. We investigated whether PTSD would be associated with increased coagulation activity. We measured resting plasma levels of clotting factor VII activity (FVII:C), FVIII:C, FXII:C, fibrinogen, and D-dimer in 14 otherwise healthy patients with PTSD and in 14 age- and gender-matched, trauma-exposed non-PTSD controls. Categorical and dimensional diagnoses of PTSD were made using the Clinician-Administered PTSD Scale (CAPS) interview. We also investigated to what extent the relationship between PTSD and coagulation measures would be confounded by demographics, cardiovascular risk factors, lifestyle variables, time since trauma, and mood. Coagulation factor levels did not significantly differ between patients with a categorical diagnosis of PTSD and controls while controlling for covariates. In all subjects, FVIII:C was predicted by hyperarousal severity (beta = 0.46, p = .014) independent of covariates and by overall PTSD symptom severity (beta = 0.38, p = .045); the latter association was of borderline significance when separately controlling for gender, smoking, exercise, and anxiety (p values <.07). In patients, fibrinogen was predicted by hyperarousal severity (beta = 0.70, p = .005) and by overall PTSD symptom severity (beta = 0.61, p = .020), with mood partially affecting these associations. FVII:C, fibrinogen, and D-dimer showed no independent association with PTSD symptoms. PTSD may elicit hypercoagulability, even at subthreshold levels, offering one psychobiological pathway by which posttraumatic stress might contribute to atherosclerosis progression and clinical cardiovascular disease.

  10. Pure eccentric exercise does not activate blood coagulation.

    PubMed

    Hilberg, Thomas; Gläser, Doreen; Prasa, Dagmar; Stürzebecher, Jörg; Gabriel, Holger H W

    2005-08-01

    Eccentric exercise can cause skeletal muscle damage with ultrastructural disruption, inflammation and increased proteolytic enzyme activity. It may be possible that these changes are able to trigger blood coagulation in vivo. The aim of the study was to investigate changes in blood coagulation via the measurement of aPTT, the thrombin potential (total [TTP] and endogenous [ETP], both intrinsic [in] and extrinsic [ex]) and the thrombin generation (prothrombinfragment 1 + 2 [F1 + 2] and thrombin-antithrombin complex [TAT]) after pure eccentric exercise. Seventeen healthy non-smokers (28 +/- 6 years, VO2-peak 59 +/- 7 ml/min/kg) underwent pure eccentric down jumps (9 x 28 isolated down jumps in 90 min, drop from a height of 55 cm), a cycle exercise (90% of the individual anaerobic threshold for 60-90 min) and a control experiment on different days. Blood samples were drawn after a 30-min rest, immediately, and 2 h after exercise. After the cycle exercise, a clear shortening by 12% (P<0.001) in aPTT and an increase in TTPin (13%; P<0.05) and TAT (33%; P<0.05) in comparison to the control experiment were seen, while after eccentric exercise only minimal changes in aPTT and thrombin potential (TTPin, ETPin) and no thrombin generation (F1 + 2 and TAT) were found. In contrast to concentric dynamic exercise, e.g. cycle ergometry, only insignificant changes in thrombin potential and no thrombin generation could be observed after skeletal muscle damage induced by pure eccentric exercise. It can be concluded that the mechanical impact associated with eccentric exercise does not activate blood coagulation.

  11. Microfiltration of different surface waters with/without coagulation: clear correlations between membrane fouling and hydrophilic biopolymers.

    PubMed

    Kimura, Katsuki; Tanaka, Ken; Watanabe, Yoshimasa

    2014-02-01

    Although low-pressure membranes (microfiltration (MF) or ultrafiltration (UF)) have become viable options for drinking water treatment, problems caused by membrane fouling must still be addressed. The objective of this study was to compare five different surface waters and to identify a relevant index of water quality that can be used for prediction of the fouling potential of the water. Bench-scale filtration tests were carried out with commercially available hollow-fiber MF membranes. Fairly long-term (a few days) filtrations in the constant-flow mode were carried out with automatic backwash. Membrane fouling in this study was shown to be irreversible as a result of the periodic backwash carried out throughout of the operation. Easily accessible indexes of water quality including dissolved organic carbon (DOC), UV absorbance, Ca concentration and turbidity could not explain the degree of fouling encountered in the filtration tests. Fluorescence excitation-emission matrix (EEM) could provide information on the presence of protein-like substances in water, and peaks for protein showed some correlation with the membrane fouling. Biopolymer (characterized by high molecular weights and insensitivity to UV light absorption) concentrations in the five waters determined by liquid chromatography with organic carbon detection (LC-OCD) exhibited an excellent correlation with the fouling rates. Coagulation with polyaluminum chloride could mitigate membrane fouling in all cases. The extent of fouling seen with coagulated waters was also correlated with biopolymer concentrations. The relationship between biopolymer concentrations and the fouling rates established for the raw waters could also be applied to the coagulated waters. These results suggested that the contribution of biopolymers to membrane fouling in the present study was significant, an observation that was supported by the analysis of foulants extracted at the termination of each test. Biopolymer concentrations

  12. Toward a definition of "fresh" whole blood: an in vitro characterization of coagulation properties in refrigerated whole blood for transfusion.

    PubMed

    Jobes, David; Wolfe, Yanika; O'Neill, Daniel; Calder, Jennifer; Jones, Lisa; Sesok-Pizzini, Deborah; Zheng, X Long

    2011-01-01

    The hemostatic property of "fresh" whole blood (WB) has been observed in military application and cardiac surgery and is associated with reduced blood loss, transfusion requirements, and donor exposures. The time from donation to transfusion defining "fresh" has not been systematically studied. We undertook an in vitro study of coagulation properties of refrigerated WB stored for 31 days. Twenty-one WB units were obtained from healthy volunteer donors and stored under standard AABB refrigerated conditions. Samples were obtained on the day after donation and again on Days 2, 4, 7, 11, 14, 17, 21, 24, and 31. Tests included complete blood count, pH, pO2, pCO2, glucose, lactate, thromboelastography (TEG), and platelet function by light transmission aggregometry (LTA). There was progressive decline in pH, pO2, glucose, and sodium, but progressive increase in potassium, pCO2, and lactate. TEG variables in all units were normal through Day 11; abnormal values in some variables in some units began on Day 14. Final aggregation levels exhibited no change from Day 1 to Day 21 with adenosine diphosphate and epinephrine, but a decline with collagen (Day 7) and ristocetin (Day 17). This in vitro study of coagulation properties demonstrates preservation of normal integrated coagulation function to a minimum of 11 days under standard conditions of refrigerated storage of WB for transfusion. These observations strongly suggest that the hemostatic quality of WB may extend beyond current transfusion practices. If confirmed clinically, this would increase availability and extend benefits of reduced donor exposure and transfusion requirements. © 2010 American Association of Blood Banks.

  13. Unlocked Concanavalin A Forms Amyloid-like Fibrils from Coagulation of Long-lived “Crinkled” Intermediates

    PubMed Central

    Vetri, Valeria; Leone, Maurizio; Morozova-Roche, Ludmilla A.; Vestergaard, Bente; Foderà, Vito

    2013-01-01

    Understanding the early events during amyloid aggregation processes is crucial to single out the involved molecular mechanisms and for designing ad hoc strategies to prevent and reverse amyloidogenic disorders. Here, we show that, in conditions in which the protein is positively charged and its conformational flexibility is enhanced, Concanavalin A leads to fibril formation via a non-conventional aggregation pathway. Using a combination of light scattering, circular dichroism, small angle X-ray scattering, intrinsic (Tryptophan) and extrinsic (ANS) fluorescence and confocal and 2-photon fluorescence microscopy we characterize the aggregation process as a function of the temperature. We highlight a multi-step pathway with the formation of an on-pathway long-lived intermediate and a subsequent coagulation of such “crinkled” precursors into amyloid-like fibrils. The process results in a temperature-dependent aggregation-coagulation pathway, with the late phase of coagulation determined by the interplay between hydrophobic and electrostatic forces. Our data provide evidence for the complex aggregation pathway for a protein with a highly flexible native conformation. We demonstrate the possibility to generate a long-lived intermediate whose proportion and occurrence are easily tunable by experimental parameters (i.e. temperature). As a consequence, in the case of aggregation processes developing through well-defined energy barriers, our results can open the way to new strategies to induce more stable in vitro on-pathway intermediate species through a minute change in the initial conformational flexibility of the protein. This will allow isolating and experimentally studying such transient species, often indicated as relevant in neurodegenerative diseases, both in terms of structural and cytotoxic properties. PMID:23874809

  14. Local Anesthesia During Interstitial Laser Coagulation of the Prostate

    PubMed Central

    Kedia, Kalish R

    2005-01-01

    With the emergence of minimally invasive therapies for the management of symptoms of benign prostatic hyperplasia (BPH), as well as the reality of a changing medical economic environment, there is a need for a reliable local anesthesia protocol. The protocol described here for prostate anesthetic block is a safe, economical, and effective way to perform interstitial laser coagulation and other minor endoscopic urologic procedures in the office setting. Most patients experience little discomfort and recover quickly, with prompt return to normal activities. Urologists should be aware of and comfortable with these techniques. PMID:16985900

  15. Effects of dimethylformamide (DMF) on coagulation and platelet activity

    SciTech Connect

    Imbriani, M.; Ghittori, S.; Prestinoni, A.; Longoni, P.; Cascone, G.; Gamba, G.

    1986-03-01

    The effects of dimethylformamide (DMF) on hemostatic functions, especially on platelet activity, were examined both in vitro and in vivo in 15 workers exposed to DMF (27 mg/m3, median value). Twenty-eight control subjects who were not exposed to DMF, but comparable for age, anthropometric data, and smoking habits, were also studied. Workers exposed to DMF showed a decrease in the number of platelets and had longer coagulation times, probably due to a change caused by DMF on the membrane receptor of platelets and on the phospholipid components of the clotting system.

  16. Disseminated Intravascular Coagulation after Surgery for Facial Injury

    PubMed Central

    Tachibana, Hirohiko; Ishikawa, Shigeo; Yusa, Kazuyuki; Kitabatake, Kenichirou; Iino, Mitsuyoshi

    2016-01-01

    A case of disseminated intravascular coagulation (DIC) presenting after surgery for facial trauma associated with multiple facial bone fractures is described. With regard to the oral and maxillofacial region, DIC has been described in the literature following head trauma, infection, and metastatic disease. Until now, only 5 reports have described DIC after surgery for facial injury. DIC secondary to facial injury is thus rare. The patient in this case was young and had no medical history. Preoperative hemorrhage or postoperative septicemia may thus induce DIC. PMID:27313913

  17. Intracellular coagulation inhibits the extraction of proteins from Prochloron

    NASA Technical Reports Server (NTRS)

    Fall, R.; Lewin, R. A.; Fall, L. R.

    1983-01-01

    Protein extraction from the prokaryotic alga Prochloron LP (isolated from the ascidian host Lissoclinum patella) was complicated by an irreversible loss of cell fragility in the isolated algae. Accompanying this phenomenon, which is termed intracellular coagulation, was a redistribution of thylakoids around the cell periphery, a loss of photosynthetic O2 production, and a drastic decrease in the extractability of cell proteins. Procedures are described for the successful preparation and transport of cell extracts yielding the enzymes glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase as well as other soluble proteins.

  18. Disseminated intravascular coagulation and the Waterhouse-Friderichsen syndrome

    PubMed Central

    Fox, B.

    1971-01-01

    In a clinico-pathological study of 13 children who died with Waterhouse-Friderichsen syndrome, there were deposits of fibrin in many organs, especially the adrenal glands and the kidneys. This finding supports the hypothesis that disseminated intravascular coagulation (DIC) occurs in this syndrome. The exact role that DIC plays has not been defined; though it probably contributes to the severe shock and the widespread haemorrhages; the adrenal haemorrhages appear not to be due directly to DIC. The presence of DIC in the Waterhouse-Friderichsen syndrome suggests that heparin should be a logical form of treatment. ImagesFIG. 1FIG. 2 PMID:5118056

  19. Intracellular coagulation inhibits the extraction of proteins from Prochloron

    NASA Technical Reports Server (NTRS)

    Fall, R.; Lewin, R. A.; Fall, L. R.

    1983-01-01

    Protein extraction from the prokaryotic alga Prochloron LP (isolated from the ascidian host Lissoclinum patella) was complicated by an irreversible loss of cell fragility in the isolated algae. Accompanying this phenomenon, which is termed intracellular coagulation, was a redistribution of thylakoids around the cell periphery, a loss of photosynthetic O2 production, and a drastic decrease in the extractability of cell proteins. Procedures are described for the successful preparation and transport of cell extracts yielding the enzymes glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase as well as other soluble proteins.

  20. Pharmacogenomics of Anti-platelet and Anti-coagulation Therapy

    PubMed Central

    Fisch, Adam S.; Perry, Christina G.; Stephens, Sarah H.; Horenstein, Richard B.; Shuldiner, Alan R.

    2013-01-01

    Arterial thrombosis is a major component of vascular disease, especially myocardial infarction (MI) and stroke. Current anti-thrombotic therapies such as warfarin and clopidogrel are effective in inhibiting cardiovascular events; however, there is great inter-individual variability in response to these medications. In recent years, it has been recognized that genetic factors play a significant role in drug response, and, subsequently, common variants in