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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. Theoretical analysis of the light interaction with coagulated tissue

    NASA Astrophysics Data System (ADS)

    Jerath, Maya R.; Welch, Ashley J.

    1992-08-01

    During laser treatment, coagulation affects the optical properties of the tissue. In particular, the formation of a white lesion increases the scattering coefficient significantly. This change in the optical properties in turn affects the laser light distribution in the tissue. For example, what is the effect of the white lesion formed during photocoagulation of the retina upon reflection and fluence rate? This problem was simulated on a model medium consisting of a thin absorbing black paint layer covered with a 1 cm thick layer of fresh egg white. The egg white layer was subdivided into coagulated (white) and uncoagulated (clear) layers. The optical properties of coagulated and uncoagulated egg white were determined. These values were used to model light distribution in the medium for varying thicknesses of the coagulated egg white layer using the one dimensional Adding Doubling method. Our results show that the fluence reaching the paint layer increase until the coagulated layer reaches 100 micrometers , after which it falls off exponentially. It was also found that the total reflected light increases almost linearly at first as the coagulated layer thickens, and then begins to level off to an R(infinity ) at a coagulation thickness of 2 mm. Experimental measurements of reflection from a lesion with a CCD camera confirm the computed trends. These results provide a theoretical foundation for control of lesion thickness using reflectance images.

  3. 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. PMID:23244324

  4. [Effect of UV Light Radiation on the Coagulation of Chlorella and Its Mechanism].

    PubMed

    Wang, Wen-dong; Zhang, Ke; Xu, Hong-bin; Liu, Guo-qi

    2016-01-15

    Considering algae were difficult to be effectively removed in conventional water treatment process, UV radiation was used to enhance the coagulation of algae in this study. The results showed that with the increase of radiation time, the removal rates of both algae and turbidity experienced a decrease after an increase, and reached their maximum values at 50 min. When the dosage of PAC was 5 mg x L(-1), the removal rates of algae and turbidity of the radiated sample were 20.1% and 18% higher than the blank sample, respectively. When pH ranged from 6 to 9, the coagulation efficiency varied little. At pH 8 and with a radiation time of 50 min, the removal rates of algae and turbidity reached 93.5% and 90.6%, respectively. Meanwhile, the Zeta potential reached the maximum, and the algae generated extracellular organic matter, which favored the subsequent coagulation. After radiated for 60 min, the algal cells was destroyed, leading to a release of intracellular organic matter into the solution. Accordingly, the Zeta potential decreased, which had a negative effect on the subsequent coagulation process. PMID:27078957

  5. Disseminated intravascular coagulation (DIC)

    MedlinePlus

    ... medlineplus.gov/ency/article/000573.htm Disseminated intravascular coagulation (DIC) To use the sharing features on this page, please enable JavaScript. Disseminated intravascular coagulation is a serious disorder in which the proteins ...

  6. Comparison of coagulation behavior and floc structure characteristic of different polyferric-cationic polymer dual-coagulants in humic acid solution.

    PubMed

    Wei, Jincheng; Gao, Baoyu; Yue, Qinyan; Wang, Yan; Li, Weiwei; Zhu, Xiaobiao

    2009-02-01

    Three polyferric-cationic polymer dual-coagulants were comparatively evaluated in terms of coagulation behavior and floc structure characteristic in the coagulation of humic acid (HA) solution. The first dual-coagulant, PFC-PDADMAC, was prepared by premixing of polyferric chloride (PFC) and polydiallyldimethylammonium (PDADMAC) before dosing. The other two were achieved by dosing PFC and PDADMAC in different order. For the given neutral condition, all three dual-coagulants gave similar HA removal before reaching optimal dosage. The strongest charge neutralization and narrowest effective coagulation dosage range were obtained when PFC was dosed firstly. While the weakest charge neutralization and the broadest effective coagulation dosage were obtained when PDADMAC was used as the primary coagulant. The HA removal of all three dual-coagulants was slightly pH dependent for optimum coagulant doses. Fe(III) hydrolysis species distributions of the dual-coagulants in coagulation process were measured by ferron method. PFC-PDADMAC gave the highest content of active Fe(III) coagulating species which is responsible for the coagulation performance of ferric coagulant. The evolution of floc size and floc fractal dimension (Df) in coagulation process was measured under optimum dose and neutral condition by laser diffraction instrument and small-angle laser light scattering (SALLS), respectively. All three dual-coagulants gave similar final floc size but different floc growth rate and floc structure. Both the growth rate and Df were in the same order: PFC dosed firstly>PDADMAC dosed firstly>PFC-PDADMAC. PMID:19046756

  7. Polyphosphate, Platelets, and Coagulation

    PubMed Central

    Travers, Richard J.; Smith, Stephanie A.; Morrissey, James H.

    2015-01-01

    While we have understood the basic outline of the enzymes and reactions that make up the traditional blood coagulation cascade for many years, recently our appreciation of the complexity of these interactions has greatly increased. This has resulted in unofficial “revisions” of the coagulation cascade to include new amplification pathways and connections between the standard coagulation cascade enzymes, as well as the identification of extensive connections between the immune system and the coagulation cascade. The discovery that polyphosphate is stored in platelet dense granules and is secreted during platelet activation has resulted in a recent burst of interest in the role of this ancient molecule in human biology. Here we review the increasingly complex role of platelet polyphosphate in hemostasis, thrombosis, and inflammation that has been uncovered in recent years, as well as novel therapeutics centered on modulating polyphosphate’s roles in coagulation and inflammation. PMID:25976958

  8. 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.

  9. 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)

  10. Disseminated intravascular coagulation (DIC)

    MedlinePlus

    ... Jr, Silberstein LE, et al, eds. Hematology: Basic Principles and Practice . 6th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 141. Thachil J, Toh CH. Current concepts in the management of disseminated intravascular coagulation. Thromb Res . 2012;129 ...

  11. Coagulation abnormalities in sepsis.

    PubMed

    Tsao, Cheng-Ming; Ho, Shung-Tai; Wu, Chin-Chen

    2015-03-01

    Although the pathophysiology of sepsis has been elucidated with the passage of time, sepsis may be regarded as an uncontrolled inflammatory and procoagulant response to infection. The hemostatic changes in sepsis range from subclinical activation of blood coagulation to acute disseminated intravascular coagulation (DIC). DIC is characterized by widespread microvascular thrombosis, which contributes to multiple organ dysfunction/failure, and subsequent consumption of platelets and coagulation factors, eventually causing bleeding manifestations. The diagnosis of DIC can be made using routinely available laboratory tests, scoring algorithms, and thromboelastography. In this cascade of events, the inhibition of coagulation activation and platelet function is conjectured as a useful tool for attenuating inflammatory response and improving outcomes in sepsis. A number of clinical trials of anticoagulants were performed, but none of them have been recognized as a standard therapy because recombinant activated protein C was withdrawn from the market owing to its insufficient efficacy in a randomized controlled trial. However, these subgroup analyses of activated protein C, antithrombin, and thrombomodulin trials show that overt coagulation activation is strongly associated with the best therapeutic effect of the inhibitor. In addition, antiplatelet drugs, including acetylsalicylic acid, P2Y12 inhibitors, and glycoprotein IIb/IIIa antagonists, may reduce organ failure and mortality in the experimental model of sepsis without a concomitant increased bleeding risk, which should be supported by solid clinical data. For a state-of-the-art treatment of sepsis, the efficacy of anticoagulant and antiplatelet agents needs to be proved in further large-scale prospective, interventional, randomized validation trials. PMID:25544351

  12. [Effects of Interaction of Ozonation and Coagulation on Coagulation Results].

    PubMed

    Liu, Hai-long; Guo, Xue-feng; Wang, Min-hui; Jiao, Ru-yuan; Shi, Jian

    2015-09-01

    Two strategies, ozonation-coagulation combination (OCC, ozone and coagulant dosed at meantime) and preozonation coagulation (PC, coagulant dosed after ozone died away) were used to treat synthesized water. Different effects of oxidation and coagulation, disinfection by-products formation potentials (DBPFP) in the same water were detected in order to study the influence of interaction of ozonation and coagulation (IOC) on treated water characteristics. Results show that there are remarkable differences between OCC and PC. IOC effects take place during OCC process, which results in variations of the distribution of hydrolyzed species of coagulant. And this is an important reason which impairs efficiency of coagulation. Turbidity after OCC was higher than that of PC. One of the main reasons is that ozone reduced the content of Alb species which was built during coagulant hydrolyzation. Cl-DBPFP in OCC outlet water were lower than those in PC because oxidized destruction of DBP precursors were enhanced by catalyzed ozonation by AlCl3 along with its other hydrolyzed species. Removals of MCAA and CF formation potentials by OCC were significantly higher than those by PC, MCAAFP were 5. 6 µg . L-1 and 16. 9 µg . L-1 respectively, and CFFP were 12. 5 µg . L-1 and 24. 1 µg . L-1 respectively. Coagulation results and DBP formations are significantly affected by interaction of ozonation and coagulation; and it should be a noticeable point of water safety if ozonation and coagulation are employed together. Thus times and spots between ozone and coagulant should be defined clearly in correlational researches and water treatment application. PMID:26717689

  13. Bacteria under stress by complement and coagulation.

    PubMed

    Berends, Evelien T M; Kuipers, Annemarie; Ravesloot, Marietta M; Urbanus, Rolf T; Rooijakkers, Suzan H M

    2014-11-01

    The complement and coagulation systems are two related protein cascades in plasma that serve important roles in host defense and hemostasis, respectively. Complement activation on bacteria supports cellular immune responses and leads to direct killing of bacteria via assembly of the Membrane Attack Complex (MAC). Recent studies have indicated that the coagulation system also contributes to mammalian innate defense since coagulation factors can entrap bacteria inside clots and generate small antibacterial peptides. In this review, we will provide detailed insights into the molecular interplay between these protein cascades and bacteria. We take a closer look at how these pathways are activated on bacterial surfaces and discuss the mechanisms by which they directly cause stress to bacterial cells. The poorly understood mechanism for bacterial killing by the MAC will be reevaluated in light of recent structural insights. Finally, we highlight the strategies used by pathogenic bacteria to modulate these protein networks. Overall, these insights will contribute to a better understanding of the host defense roles of complement and coagulation against bacteria. PMID:25065463

  14. Disseminated intravascular coagulation.

    PubMed

    Gando, Satoshi; Levi, Marcel; Toh, Cheng-Hock

    2016-01-01

    Disseminated intravascular coagulation (DIC) is an acquired syndrome characterized by widespread intravascular activation of coagulation that can be caused by infectious insults (such as sepsis) and non-infectious insults (such as trauma). The main pathophysiological mechanisms of DIC are inflammatory cytokine-initiated activation of tissue factor-dependent coagulation, insufficient control of anticoagulant pathways and plasminogen activator inhibitor 1-mediated suppression of fibrinolysis. Together, these changes give rise to endothelial dysfunction and microvascular thrombosis, which can cause organ dysfunction and seriously affect patient prognosis. Recent observations have pointed to an important role for extracellular DNA and DNA-binding proteins, such as histones, in the pathogenesis of DIC. The International Society on Thrombosis and Haemostasis (ISTH) established a DIC diagnostic scoring system consisting of global haemostatic test parameters. This scoring system has now been well validated in diverse clinical settings. The theoretical cornerstone of DIC management is the specific and vigorous treatment of the underlying conditions, and DIC should be simultaneously managed to improve patient outcomes. The ISTH guidance for the treatment of DIC recommends treatment strategies that are based on current evidence. In this Primer, we provide an updated overview of the pathophysiology, diagnosis and management of DIC and discuss the future directions of basic and clinical research in this field. PMID:27250996

  15. [Samples in Coagulation Test].

    PubMed

    Komiyama, Yutaka

    2015-12-01

    An understanding and ability to develop a strategy to prevent pre-analytical errors of laboratory tests in the hemostasis area are two of the most important skills of medical technologists and related doctors. Recently, the working group for standardization of sampling in coagulation tests is working towards a consensus. This article reviews a summary of the consensus: (1) The anticoagulant for coagulation tests is 3.13-3.2% sodium citrate at a ratio of 1:9 to whole blood and the accuracy of the ratio is within 10%. (2) Blood sampling is achieved with the use of a 21-23G needle and coagulation. Blood sampling can be achieved by both a syringe and vacuum tube system. After taking blood, laboratory tests such as of the prothrombin time (PT) and activated partial thromboplastin time (APTT) should be completed within one hour and the storage temperature should be at room temperature, not ice-cold conditions. 3) To prepare a plasma sample, citrated blood is centrifuged at 1,500 x g for 15 min at room temperature to minimize the remaining platelets in plasma (below 10,000/microL at least). PMID:27089656

  16. 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

  17. [Interstitial laser coagulation of benign prostatic hyperplasia].

    PubMed

    Muschter, R; Hessel, S; Hofstetter, A; Keiditsch, E; Rothenberger, K H; Schneede, P; Frank, F

    1993-07-01

    We report on the new method of interstitial laser coagulation for the treatment of benign prostatic hyperplasia (BPH). The procedure is based on the interstitial application of Nd:YAG laser irradiation, delivered through a new light guide system. Such light applicators coagulate constant tissue volumes in a homogeneous manner, as proven by in vitro studies in different tissues, including surgically removed prostate adenoma. The extent of the coagulation is determined by laser power and irradiation time. At 5 W, for example, and during a 10-min period, this zone reached a diameter of up to 20 mm. Temperatures generated in the process were over 100 degrees C, as measured by time/space resolution. These results were confirmed by in vivo studies in canine prostates. In the course of 7 weeks, the coagulated areas formed scars with degeneration and fibrosis, accompanied by marked shrinking. Neighbouring organs were not affected. The method was successfully transferred to clinical practice. The application of the light guides to the lateral lobes was performed percutaneously from the perineum under transrectal ultrasound guidance. The median lobe was punctured transurethrally under direct vision. Twenty-seven patients with an average age of 67.7 years were treated between July 1991 and March 1992. At the time of evaluation 15 patients had a follow-up of more than 2 months. They experienced a mean increase of peak flow rate from 6.6 to 15.2 ml/s and a mean decrease of residual volume from 206 to 38 ml. This was accompanied by a marked lessening of symptoms. The average prostate weight decreased from 63 to 44 g. Sexually active patients did not experience retrograde ejaculation.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7690498

  18. 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.

  19. Thermophoretically Dominated Aerosol Coagulation

    NASA Astrophysics Data System (ADS)

    Rosner, Daniel E.; Arias-Zugasti, Manuel

    2011-01-01

    A theory of aerosol coagulation due to size-dependent thermophoresis is presented. This previously overlooked effect is important when local temperature gradients are large, the sol population is composed of particles of much greater thermal conductivity than the carrier gas, with mean diameters much greater than the prevailing gas mean free path, and an adequate “spread” in sizes (as in metallurgical mists or fumes). We illustrate this via a population-balance analysis of the evolution of an initially log-normal distribution when this mechanism dominates ordinary Brownian diffusion.

  20. How Is Disseminated Intravascular Coagulation Treated?

    MedlinePlus

    ... the NHLBI on Twitter. How Is Disseminated Intravascular Coagulation Treated? Treatment for disseminated intravascular coagulation (DIC) depends ... and treat the underlying cause. Acute Disseminated Intravascular Coagulation People who have acute DIC may have severe ...

  1. 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. PMID:17651081

  2. Coagulation products and their uses.

    PubMed

    Shord, S S; Lindley, C M

    2000-08-01

    The indications, pharmacokinetics, and therapeutic guidelines for available coagulation products are reviewed. Patients with hemophilia, von Willebrand's disease (VWD), or acquired inhibitors to antihemophilic factor (AHF) cannot spontaneously stop an acute hemorrhage. Coagulation products used to manage bleeding in patients with these disorders include AHF concentrates, factor IX concentrates, factor VIIa concentrate, factor IX complexes, anti-inhibitor coagulant complexes, and desmopressin acetate. Typically, these commercially available products are used to manage acute bleeding or to prevent excessive bleeding during surgery. The dosage of the coagulation products and the duration of therapy depend on many variables, including the severity of the hemorrhage, the pharmacokinetics of the coagulation products, and patient-specific factors. Product purity and viral attenuation are also important considerations in determining an appropriate dosage regimen. Recombinant versions of some coagulant factors are available and can eliminate the risk of viral transmission. A thorough understanding of each coagulation product can guide product selection, dosing, and treatment duration and can reduce the risk of viral transmission. PMID:10938981

  3. Platelets and coagulation in infection

    PubMed Central

    Davis, Rachelle P; Miller-Dorey, Sarah; Jenne, Craig N

    2016-01-01

    Disseminated intravascular coagulation (DIC) is a frequent complication in sepsis that is associated with worse outcomes and higher mortality in patients. In addition to the uncontrolled generation of thrombi throughout the patient's vasculature, DIC often consumes large quantities of clotting factors leaving the patient susceptible to hemorrhaging. Owing to these complications, patients often receive anticoagulants to treat the uncontrolled clotting, often with mixed outcomes. This lack of success with the current array of anticoagulants can be partly explained by the fact that during sepsis clotting is often initiated by the immune system. Systemic inflammation has the capacity to activate and amplify coagulation and, as such, potential therapies for the treatment of sepsis-associated DIC need to address the interaction between inflammation and coagulation. Recent studies have suggested that platelets and neutrophil extracellular traps (NETs) are the key mediators of infection-induced coagulation. This review explores current anticoagulant therapies and discusses the development of future therapies to target platelet and NET-mediated coagulation. PMID:27525062

  4. 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.

  5. 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.

  6. Coagulation factor XII protease domain crystal structure

    PubMed Central

    Pathak, M; Wilmann, P; Awford, J; Li, C; Hamad, BK; Fischer, PM; Dreveny, I; Dekker, LV; Emsley, J

    2015-01-01

    Background Coagulation factor XII is a serine protease that is important for kinin generation and blood coagulation, cleaving the substrates plasma kallikrein and FXI. Objective To investigate FXII zymogen activation and substrate recognition by determining the crystal structure of the FXII protease domain. Methods and results A series of recombinant FXII protease constructs were characterized by measurement of cleavage of chromogenic peptide and plasma kallikrein protein substrates. This revealed that the FXII protease construct spanning the light chain has unexpectedly weak proteolytic activity compared to β-FXIIa, which has an additional nine amino acid remnant of the heavy chain present. Consistent with these data, the crystal structure of the light chain protease reveals a zymogen conformation for active site residues Gly193 and Ser195, where the oxyanion hole is absent. The Asp194 side chain salt bridge to Arg73 constitutes an atypical conformation of the 70-loop. In one crystal form, the S1 pocket loops are partially flexible, which is typical of a zymogen. In a second crystal form of the deglycosylated light chain, the S1 pocket loops are ordered, and a short α-helix in the 180-loop of the structure results in an enlarged and distorted S1 pocket with a buried conformation of Asp189, which is critical for P1 Arg substrate recognition. The FXII structures define patches of negative charge surrounding the active site cleft that may be critical for interactions with inhibitors and substrates. Conclusions These data provide the first structural basis for understanding FXII substrate recognition and zymogen activation. PMID:25604127

  7. Monitoring the blood coagulation process under various flow conditions with optical coherence tomography.

    PubMed

    Xu, Xiangqun; Geng, Jinhai; Teng, Xiangshuai

    2014-04-01

    Our previous work demonstrated that an optical coherence tomography (OCT) technique was able to characterize the whole blood coagulation process. The 1/e light penetration depth (d(1/e)) derived from the profiles of reflectance versus depth was developed for detecting the whole blood coagulation process in static state. To consider the effect of blood flow, in the present study, d(1/e) versus time from the coagulating porcine blood circulated in a mock flow loop with various steady laminar flows at mean flow speed in the range from 5 to 25  mm/s. The variation of d(1/e) was used to represent the change of blood properties during coagulation in different hematocrits (HCT) ranging from 25% to 55%, velocities from 5 to 25  mm/s, and tubing sizes from 0.9 to 2 mm. The results showed that there were positive correlations between coagulation time (t(c)) and HCT, velocity, and tubing size, respectively. In addition, the coagulation rate (S(r)) was decreased with the increase of HCT, velocity, and tubing size. This study testified that HCT, flow velocity, and tubing size were substantial factors affecting the backscattering properties during flowing blood coagulation. Furthermore, OCT has the potential to represent the process of flowing blood coagulation with proper parameters. PMID:24781589

  8. Computer simulation of the coagulation of suspended solids - The applicability of the Müller-Smoluchowski theory.

    PubMed

    Wardzynska, Regina; Załęska-Chróst, Beata

    2016-06-01

    The results of studies carried out using a computer programme simulating the coagulation of suspensions containing spherical sol particles and spherical coagulant particles are reported. The influence of the degree of dispersion of the system on the coagulation reaction kinetics was investigated. The obtained results of kinetic studies were tested in the light of classical Müller-Smoluchowski equations. The influence of the physical properties of the coagulant, such as size, density and mass, on the coagulation rate was tested. It was found that within the range described in this paper, the rate of the simulated coagulation process fulfils both the kinetic equation of a first-order reaction, and the kinetic equation of a second-order reaction. Within the tested range, a significant influence of the mass and size of the coagulant on the coagulation rate was ascertained. The kinetic Müller-Smoluchowski dependence is fulfilled in a broader range of the degree of dispersion, when the coagulant particle mass and the sol particle mass are equal. When the particle mass increases with an increase in the particle radius, the coagulation rate increases faster that it would result from the Müller's dependence. PMID:27266316

  9. Effects of Glucides on Thermal Denaturation and Coagulation of Whey Proteins Studied by Ultraviolet Spectroscopy

    NASA Astrophysics Data System (ADS)

    Mongo Antoine, Etou; Abena, A. A.; Gbeassor, M.; Chaveron, H.

    The thermal coagulation of whey proteins concentrates was inhibited by various glucides. The disaccharides, saccharose and lactose, were most effective and the amino sugar, glucosamine, least effective in this respect. Ultraviolet absorption and light-scattering measurements on thermal denaturation and coagulation of both unfractionated and individual whey proteins (α-lactalbumin, ß-lactoglobulin and bovine serum albumin) showed that saccharose promotes the denaturation of these proteins but inhibits their subsequent coagulation. These results are interpreted in terms of the effect of saccharose on the hydrophobic interactions between solvent and protein.

  10. 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.

  11. Gene Therapy for Coagulation Disorders.

    PubMed

    Swystun, Laura L; Lillicrap, David

    2016-04-29

    Molecular genetic details of the human coagulation system were among the first successes of the genetic revolution in the 1980s. This information led to new molecular diagnostic strategies for inherited disorders of hemostasis and the development of recombinant clotting factors for the treatment of the common inherited bleeding disorders. A longer term goal of this knowledge has been the establishment of gene transfer to provide continuing access to missing or defective hemostatic proteins. Because of the relative infrequency of inherited coagulation factor disorders and the availability of safe and effective alternative means of management, the application of gene therapy for these conditions has been slow to realize clinical application. Nevertheless, the tools for effective and safe gene transfer are now much improved, and we have started to see examples of clinical gene therapy successes. Leading the way has been the use of adeno-associated virus-based strategies for factor IX gene transfer in hemophilia B. Several small phase 1/2 clinical studies using this approach have shown prolonged expression of therapeutically beneficial levels of factor IX. Nevertheless, before the application of gene therapy for coagulation disorders becomes widespread, several obstacles need to be overcome. Immunologic responses to the vector and transgenic protein need to be mitigated, and production strategies for clinical grade vectors require enhancements. There is little doubt that with the development of more efficient and facile strategies for genome editing and the application of other nucleic acid-based approaches to influence the coagulation system, the future of genetic therapies for hemostasis is bright. PMID:27126652

  12. Comparison of coagulation performance and floc properties using a novel zirconium coagulant against traditional ferric and alum coagulants.

    PubMed

    Jarvis, Peter; Sharp, Emma; Pidou, Marc; Molinder, Roger; Parsons, Simon A; Jefferson, Bruce

    2012-09-01

    Coagulation in drinking water treatment has relied upon iron (Fe) and aluminium (Al) salts throughout the last century to provide the bulk removal of contaminants from source waters containing natural organic matter (NOM). However, there is now a need for improved treatment of these waters as their quality deteriorates and water quality standards become more difficult to achieve. Alternative coagulant chemicals offer a simple and inexpensive way of doing this. In this work a novel zirconium (Zr) coagulant was compared against traditional Fe and Al coagulants. The Zr coagulant was able to provide between 46 and 150% lower dissolved organic carbon (DOC) residual in comparison to the best traditional coagulant (Fe). In addition floc properties were significantly improved with larger and stronger flocs forming when the Zr coagulant was used with the median floc sizes being 930 μm for Zr; 710 μm for Fe and 450 μm for Al. In pilot scale experiments, a similar improved NOM and particle removal was observed. The results show that when optimised for combined DOC removal and low residual turbidity, the Zr coagulant out-performed the other coagulants tested at both bench and pilot scale. PMID:22627114

  13. A `triangle' of interconnected coagulation models

    NASA Astrophysics Data System (ADS)

    Dubovski, P. B.

    1999-02-01

    A number of new coagulation models depending on a parameter is derived. The dependence is considered in two different ways. If the parameter takes its maximal value then in the first case we obtain a new discrete kinetic equation. We demonstrate that its continuous version is simply the Oort-Hulst's coagulation model. In the second case, the maximum of the corresponding parameter yields the Smoluchowski coagulation equation. At the minimal values of both parameters we arrive at another new kinetic equation. These three models form a `triangle' connecting the two known coagulation equations `situated' in its vertexes (Smoluchowski and Oort-Hulst equations) via an alteration of the parameters. Also, a comparative analysis of these three models is presented. As an advantage of the Oort-Hulst approach we compute the coagulation front and establish a connection between the infringement of the mass conservation law and convergence of the coagulation front to infinity.

  14. [Cellular model of blood coagulation process].

    PubMed

    Bijak, Michał; Rzeźnicka, Paulina; Saluk, Joanna; Nowak, Paweł

    2015-07-01

    Blood coagulation is a process which main objective is the prevention of blood loss when the integrity of the blood vessel is damaged. Over the years, have been presented a number of concepts characterizing the mechanism of thrombus formation. Since the 60s of last century was current cascade model of the coagulation wherein forming of the fibrin clot is determined by two pathways called extrinsic and intrinsic pathways. In the nineties of the last century Monroe and Hoffman presented his concept of blood coagulation process which complement the currently valid model of cells participation especially of blood platelets which aim is to provide a negatively charged phospholipid surface and thereby allow the coagulation enzymatic complexes formation. Developed conception they called cellular model of coagulation. The aim of this work was to present in details of this blood coagulation, including descriptions of its various phases. PMID:26277170

  15. 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

  16. Interstitial laser coagulation of the prostate: experimental studies

    NASA Astrophysics Data System (ADS)

    McNicholas, Thomas A.; Steger, Adrian C.; Bown, Stephen G.; O'Donoghue, Neil

    1991-07-01

    A percutaneous, low power, interstitial method of controlled tissue coagulation by laser light has been developed and assessed as a possible alternative to existing therapy for benign and malignant prostatic disease. For prostate cancer this technique may be of importance when the tumor volume is small and well defined, particularly as these tumors can increasingly be identified by transrectal ultrasound (TRUS) and are unlikely to have metastasised. The possibility therefore arises of destruction of such small lesions in situ, thereby avoiding the need for radical surgery or radiotherapy. Using the male beagle prostate model, one or more 150-400 micron fibers was implanted within the substance of the prostate through which a Yttrium Aluminum Garnet (YAG) laser energy could be transmitted. Using long exposures and lower powers than used in routine endoscopic laser therapy, well-defined areas of coagulative necrosis could be created without extensive tissue charring or damage to the fiber. For an energy dose of 1000J a lesion approximately 1 cm in diameter results at four days. The ultrasound scanning methods can detect the fiber(s) and the area(s) of coagulation. At 6/52 months following treatment, healing was by fibrosis or cystic degeneration. There were no ill effects on the subjects following coagulation of the prostate. Multiple fiber experiments produced larger volume lesions relevant to more extensive cancer or for the coagulation of benign adenomatous hyperplasia causing outflow symptoms. Ultrasound guided clinical treatments in patients with cutaneous metastases or hepatic and pancreatic tumors have confirmed the experimental results so far obtained. The technique may prove of value for the destruction of early, small, focal tumors of the prostate and for the treatment of moderate benign enlargement. Clinical trial for both benign and malignant disease has commenced.

  17. [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. PMID:27337892

  18. 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.

  19. 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. PMID:14655704

  20. 21 CFR 864.5400 - Coagulation instrument.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 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 § 864.5400 Coagulation instrument. (a) Identification. A coagulation instrument is an automated...

  1. 21 CFR 864.5400 - Coagulation instrument.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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 § 864.5400 Coagulation instrument. (a) Identification. A coagulation instrument is an automated...

  2. 21 CFR 864.5400 - Coagulation instrument.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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 § 864.5400 Coagulation instrument. (a) Identification. A coagulation instrument is an automated...

  3. 21 CFR 864.5400 - Coagulation instrument.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 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 § 864.5400 Coagulation instrument. (a) Identification. A coagulation instrument is an automated...

  4. 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.

  5. Coagulation problems in human pregnancy.

    PubMed Central

    Redman, C. W.

    1979-01-01

    Coagulation problems in pregnancy are primarily associated with overactivity of the intrinsic clotting system. This accounts for the increased incidence of thrombo-embolism during pregnancy. Where specific obstetric complications cause clotting problems the common underlying feature is usually placental pathology as in abruptio placentae, pre-eclampsia or hydatidiform mole. Abnormal activation of the clotting system is an early, and occasionally the first detectable feature of pre-eclampsia, but there is no evidence that this is a primary change. Therefore the role of anticoagulant treatment in the management of pre-eclampsia remains questionable. A new test for estimating factor VIII consumption is proving to be a sensitive index of early activation of the clotting system and can be used for the diagnosis of early pre-eclampsia. PMID:382170

  6. 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.

  7. 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.

  8. Enhanced coagulation for high alkalinity and micro-polluted water: the third way through coagulant optimization.

    PubMed

    Yan, Mingquan; Wang, Dongsheng; Qu, Jiuhui; Ni, Jinren; Chow, Christopher W K

    2008-04-01

    Conventional coagulation is not an effective treatment option to remove natural organic matter (NOM) in water with high alkalinity/pH. For this type of water, enhanced coagulation is currently proposed as one of the available treatment options and is implemented by acidifying the raw water and applying increased doses of hydrolyzing coagulants. Both of these methods have some disadvantages such as increasing the corrosive tendency of water and increasing cost of treatment. In this paper, an improved version of enhanced coagulation through coagulant optimization to treat this kind of water is demonstrated. A novel coagulant, a composite polyaluminum chloride (HPAC), was developed with both the advantages of polyaluminum chloride (PACl) and the additive coagulant aids: PACl contains significant amounts of highly charged and stable polynuclear aluminum hydrolysis products, which is less affected by the pH of the raw water than traditional coagulants (alum and ferric salts); the additives can enhance both the charge neutralization and bridging abilities of PACl. HPAC exhibited 30% more efficiency than alum and ferric salts in dissolved organic carbon (DOC) removal and was very effective in turbidity removal. This result was confirmed by pilot-scale testing, where particles and organic matter were removed synergistically with HPAC as coagulant by sequential water treatment steps including pre-ozonation, coagulation, flotation and sand filtration. PMID:18206207

  9. Development of the selective coagulation process

    SciTech Connect

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

    1991-01-01

    Recent studies have resulted in the development of a novel agglomeration process for upgrading ultrafine coal. This process, which is known as selective hydrophobic coagulation (SHC), is based on the new finding that hydrophobic coal particles can be selectively coagulated in the presence of dispersed mineral matter. The driving force for the coagulation is believed to be due to the structural arrangement of water molecules near the coal surface. In most cases, simple pH control is all that is required to (1) induce the coagulation of the coal particles and (2) effectively disperse the particles of mineral matter. During the past quarter, several important aspects of the SHC process were examined. Direct measurements of the surface forces which control the selective coagulation process were conducted using a Mark 4 surface force apparatus. These preliminary measurements have provided irrefutable evidence for the existence of the hydrophobic force. Key expressions have been presented for a population balance model describing the hydrophobic coagulation process. In order to validate this model, experimental measurements of the size distributions of coal coagulation have been initiated. The liberation characteristics of samples obtained from the Elkhorn No. 3 and Pittsburgh No. 8 coal seams were determined using a SEM-IPS image processing system. Mixing studies were carried out to determine the effects of mixer-impeller configurations on the coagula size distributions. Bench-scale continuous testing has also been initiated during the past quarter using a rotating drum screen and sedimentation tank. 25 figs., 8 tabs.

  10. Resection of meningiomas with implantable microwave coagulation

    SciTech Connect

    Zhou, X.P.; Xie, Q.L.; Liu, J.M.; Yue, Z.J.; Cai, K.H.

    1996-05-01

    Implantable microwave coagulation was used to perform resection on 62 patients that had intracranial meningiomas. When 20--60 W microwave power was applied for 15 s, the temperature at the center of the tumor tissue was 43--63 C; 30 mm from the center, the temperature was under 40 C. Histological changes in the center of the tumor showed coagulative necrosis, diminished nuclei, and obliterated blood vessels. The changes at 10--20 mm from the center of the tumor showed coagulative necrosis and degeneration and, 30--50 mm from the center of the tumor, showed normal cell morphology after microwave coagulation. The thermal field in brain tumor has an effective diameter of about 40 mm. No side effects on the normal brain tissues were observed. The amount of blood loss during the operation was minimal while the meningioma was coagulated, especially when the meningioma was located at the skull base or in the parasagittal or cerebral convexity region. After microwave coagulation, the entire tumor could easily be removed. Among the 62 surgically treated cases, gross total tumor excision was 85%. No postoperative complications occurred after microwave coagulation, and there was no operative mortality in the series. The authors believe that this new technique has the advantage of simplicity, less blood loss, and smooth postoperative procedures. Hemostatic effects during the operation are satisfactory, and blood transfusion can be reduced by 50--60%.

  11. 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. PMID:24876736

  12. The singular coagulation equation with multiple fragmentation

    NASA Astrophysics Data System (ADS)

    Saha, Jitraj; Kumar, Jitendra

    2015-06-01

    In this paper, we prove the global existence and uniqueness of the solutions to the initial-value problem for the coagulation-fragmentation equation with singular coagulation kernel and multiple fragmentation kernel. The solution obtained in this case also satisfies the mass conservation law. The proof is based on strong convergence methods applied to suitably chosen unbounded coagulation kernels having singularities in both the coordinate axes and satisfying certain growth conditions, which can possibly reach up to a quadratic growth at infinity, and the fragmentation kernel covers a very large class of unbounded functions.

  13. 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

  14. Coagulation and fragmentation with discrete mass loss

    NASA Astrophysics Data System (ADS)

    Blair, Pamela N.; Lamb, Wilson; Stewart, Iain W.

    2007-05-01

    A nonlinear integro-differential equation that models a coagulation and multiple fragmentation process in which discrete fragmentation mass loss can occur is examined using the theory of strongly continuous semigroups of operators. Under the assumptions that the coagulation kernel is bounded and the fragmentation rate function a satisfies a linear growth condition, global existence and uniqueness of solutions that lose mass in accordance with the model are established. In the case when no coagulation is present and the fragmentation process is governed by power-law kernels, an explicit formula is given for the substochastic semigroup associated with the resulting mass-loss fragmentation equation.

  15. 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.

  16. 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. PMID:23437650

  17. Disseminated intravascular coagulation after multiple honeybee stings.

    PubMed

    V, Dharma Rao; Bodepudi, Sravan Kumar; Krishna, Murali

    2014-01-01

    Honeybee venom contains apitoxin which can cause anaphylaxis, cardiovascular collapse and death. Disseminated intravascular coagulation is rare following honeybee stings. We describe the case of a farmer who developed this complication. PMID:25668084

  18. ARSENIC REMOVAL BY SOFTENING AND COAGULATION

    EPA Science Inventory

    Drinking water regulations for arsenic (As) and disinfection by-product precursor materials (measured as TOC) are becoming increasingly stringent. Among the modifications to conventional treatment that can improve removal of As and TOC, precipitative softening and coagulation are...

  19. 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. PMID:27192355

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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. PMID:23820940

  5. Coagulation Factor XIIIa Substrates in Human Plasma

    PubMed Central

    Nikolajsen, Camilla Lund; Dyrlund, Thomas F.; Poulsen, Ebbe Toftgaard; Enghild, Jan J.; Scavenius, Carsten

    2014-01-01

    Coagulation factor XIII (FXIII) is a transglutaminase with a well defined role in the final stages of blood coagulation. Active FXIII (FXIIIa) catalyzes the formation of ϵ-(γ-glutamyl)lysine isopeptide bonds between specific Gln and Lys residues. The primary physiological outcome of this catalytic activity is stabilization of the fibrin clot during coagulation. The stabilization is achieved through the introduction of cross-links between fibrin monomers and through cross-linking of proteins with anti-fibrinolytic activity to fibrin. FXIIIa additionally cross-links several proteins with other functionalities to the clot. Cross-linking of proteins to the clot is generally believed to modify clot characteristics such as proteolytic susceptibility and hereby affect the outcome of tissue damage. In the present study, we use a proteomic approach in combination with transglutaminase-specific labeling to identify FXIIIa plasma protein substrates and their reactive residues. The results revealed a total of 147 FXIIIa substrates, of which 132 have not previously been described. We confirm that 48 of the FXIIIa substrates were indeed incorporated into the insoluble fibrin clot during the coagulation of plasma. The identified substrates are involved in, among other activities, complement activation, coagulation, inflammatory and immune responses, and extracellular matrix organization. PMID:24443567

  6. 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.

  7. Magnetic particle imaging of blood coagulation

    NASA Astrophysics Data System (ADS)

    Murase, Kenya; Song, Ruixiao; Hiratsuka, Samu

    2014-06-01

    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 CaCl2 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.

  8. 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.

  9. 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.

  10. Coagulation, Protease Activated Receptors and Viral Myocarditis

    PubMed Central

    Antoniak, Silvio; Mackman, Nigel

    2013-01-01

    The coagulation protease cascade plays an essential role in hemostasis. In addition, a clot contributes to host defense by limiting the spread of pathogens. Coagulation proteases induce intracellular signaling by cleavage of cell surface receptors called protease-activated receptors (PARs). These receptors allow cells to sense changes in the extracellular environment, such as infection. Viruses activate the coagulation cascade by inducing tissue factor expression and by disrupting the endothelium. Virus infection of the heart can cause myocarditis, cardiac remodeling and heart failure. Recent studies using a mouse model have shown that tissue factor, thrombin and PAR-1 signaling all positively regulate the innate immune during viral myocarditis. In contrast, PAR-2 signaling was found to inhibit interferon-β expression and the innate immune response. These observations suggest that anticoagulants may impair the innate immune response to viral infection and that inhibition of PAR-2 may be a new target to reduce viral myocarditis.. PMID:24203054

  11. Alterations in coagulation following major liver resection.

    PubMed

    Mallett, S V; Sugavanam, A; Krzanicki, D A; Patel, S; Broomhead, R H; Davidson, B R; Riddell, A; Gatt, A; Chowdary, P

    2016-06-01

    The international normalised ratio is frequently raised in patients who have undergone major liver resection, and is assumed to represent a potential bleeding risk. However, these patients have an increased risk of venous thromboembolic events, despite conventional coagulation tests indicating hypocoagulability. This prospective, observational study of patients undergoing major hepatic resection analysed the serial changes in coagulation in the early postoperative period. Thrombin generation parameters and viscoelastic tests of coagulation (thromboelastometry) remained within normal ranges throughout the study period. Levels of the procoagulant factors II, V, VII and X initially fell, but V and X returned to or exceeded normal range by postoperative day five. Levels of factor VIII and Von Willebrand factor were significantly elevated from postoperative day one (p < 0.01). Levels of the anticoagulants, protein C and antithrombin remained significantly depressed on postoperative day five (p = 0.01). Overall, the imbalance between pro- and anticoagulant factors suggested a prothrombotic environment in the early postoperative period. PMID:27030945

  12. 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. PMID:22261659

  13. 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

  14. Application of psyllium husk as coagulant and coagulant aid in semi-aerobic landfill leachate treatment.

    PubMed

    Al-Hamadani, Yasir A J; Yusoff, Mohd Suffian; Umar, Muhammad; Bashir, Mohammed J K; Adlan, Mohd Nordin

    2011-06-15

    Landfill leachate is a heavily polluted and a likely hazardous liquid that is produced as a result of water infiltration through solid wastes generated industrially and domestically. This study investigates the potential of using psyllium husk as coagulant and coagulant aid for the treatment of landfill leachate. Psyllium husk has been tested as primary coagulant and as coagulant aid with poly-aluminum chloride (PACl) and aluminum sulfate (alum). As primary coagulant, the optimum dosage and pH for PACl were 7.2 and 7.5 g/L, respectively, with removal efficiencies of 55, 80 and 95% for COD, color and TSS, respectively. For alum, the optimum conditions were 11 g/L alum dosage and pH 6.5 with removal efficiencies of 58, 79 and 78% for COD, color and TSS, respectively. The maximum removal efficiencies of COD, color and TSS were 64, 90 and 96%, respectively, when psyllium husk was used as coagulant aid with PACl. Based on the results, psyllium husk was found to be more effective as coagulant aid with PACl in the removal of COD, color and TSS as compared to alum. Zeta potential test was carried out for leachate, PACl, alum and psyllium husk before and after running the jar test to enhance the results of the jar test experiments. PMID:21507572

  15. 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. PMID:27387003

  16. 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. PMID:21075521

  17. [Relationship among coagulation effect of Al-based coagulant, content and speciation of residual aluminum].

    PubMed

    Yang, Zhong-Lian; Gao, Bao-Yu; Yue, Qin-Yan; Jiang, Yi-Shuai

    2010-06-01

    The application of AlCl3, Al2 (SO4)3 and poly-aluminum chloride (PAC) in humic acid-kaolin simulated water was studied in this article. It is intended to discuss the relationship among coagulation effect of Al-based coagulants in humic acid-kaolin simulated water and content and speciation of residual aluminum. It was found that, the turbidity removal efficiency and UV254 removal efficiency could reach about 90% at the tested dosage. At higher dosage, PAC gave better coagulation effect. The residual total aluminum content and residual aluminum ratio of PAC, which was 0.9 mg/L and - 3.0% or so respectively, were greatly lower than those of AlCl3 and Al2 (SO4)3. The residual total dissolved aluminum was the predominant content in the effluent after coagulation and sedimentation by the three Al-based coagulants. For the total dissolved aluminum, the proportion of dissolved organic aluminum was significantly higher than that of other aluminum speciation. With respect to humic acid-kaolin simulated water, the content of residual total aluminum in the effluent after coagulation and sedimentation by PAC decreased obviously compared to AlCl3 and Al2 (SO4)3. PAC could effectively decrease the content of residual dissolved aluminum speciation which has higher toxicity. The content of residual total dissolved aluminum in the effluent after coagulation and sedimentation by PAC was about 0.6 mg/L. PMID:20698270

  18. 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.

  19. 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.

  20. 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.

  1. Weak solutions to the continuous coagulation equation with multiple fragmentation

    PubMed Central

    Giri, Ankik Kumar; Laurençot, Philippe; Warnecke, Gerald

    2012-01-01

    The existence of weak solutions to the continuous coagulation equation with multiple fragmentation is shown for a class of unbounded coagulation and fragmentation kernels, the fragmentation kernel having possibly a singularity at the origin. This result extends previous ones where either boundedness of the coagulation kernel or no singularity at the origin for the fragmentation kernel was assumed. PMID:22389550

  2. Gelation and mass conservation in coagulation-fragmentation models

    NASA Astrophysics Data System (ADS)

    Escobedo, M.; Laurençot, Ph.; Mischler, S.; Perthame, B.

    The occurrence of gelation and the existence of mass-conserving solutions to the continuous coagulation-fragmentation equation are investigated under various assumptions on the coagulation and fragmentation rates, thereby completing the already known results. A non-uniqueness result is also established and a connection to the modified coagulation model of Flory is made.

  3. Roles for vitamin K beyond coagulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  4. 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.

  5. 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

  6. Chronic Rhinosinusitis and the Coagulation System.

    PubMed

    Kim, Dong Young; Cho, Seong H; Takabayashi, Tetsuji; Schleimer, Robert P

    2015-09-01

    Chronic rhinosinusitis (CRS) is one of the most common chronic diseases in adults and severely affects quality of life in patients. Although various etiologic and pathogenic mechanisms of CRS have been proposed, the causes of CRS remain uncertain. Abnormalities in the coagulation cascade may play an etiologic role in many diseases, such as asthma and other inflammatory conditions. While studies on the relationship between asthma and dysregulated coagulation have been reported, the role of the coagulation system in the pathogenesis of CRS has only been considered following recent reports. Excessive fibrin deposition is seen in nasal polyp (NP) tissue from patients with chronic rhinosinusitis with nasal polyp (CRSwNP) and is associated with activation of thrombin, reduction of tissue plasminogen activator (t-PA) and upregulation of coagulation factor XIII-A (FXIII-A), all events that can contribute to fibrin deposition and crosslinking. These findings were reproduced in a murine model of NP that was recently established. Elucidation of the mechanisms of fibrin deposition may enhance our understanding of tissue remodeling in the pathophysiology of NP and provide new targets for the treatment of CRSwNP. PMID:26122502

  7. Chronic Rhinosinusitis and the Coagulation System

    PubMed Central

    Kim, Dong-Young; Cho, Seong H.; Takabayashi, Tetsuji

    2015-01-01

    Chronic rhinosinusitis (CRS) is one of the most common chronic diseases in adults and severely affects quality of life in patients. Although various etiologic and pathogenic mechanisms of CRS have been proposed, the causes of CRS remain uncertain. Abnormalities in the coagulation cascade may play an etiologic role in many diseases, such as asthma and other inflammatory conditions. While studies on the relationship between asthma and dysregulated coagulation have been reported, the role of the coagulation system in the pathogenesis of CRS has only been considered following recent reports. Excessive fibrin deposition is seen in nasal polyp (NP) tissue from patients with chronic rhinosinusitis with nasal polyp (CRSwNP) and is associated with activation of thrombin, reduction of tissue plasminogen activator (t-PA) and upregulation of coagulation factor XIII-A (FXIII-A), all events that can contribute to fibrin deposition and crosslinking. These findings were reproduced in a murine model of NP that was recently established. Elucidation of the mechanisms of fibrin deposition may enhance our understanding of tissue remodeling in the pathophysiology of NP and provide new targets for the treatment of CRSwNP. PMID:26122502

  8. 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. PMID:27451044

  9. 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 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 §...

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

    PubMed

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

    2016-04-01

    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). PMID:26974542

  11. The removal of anionic surfactants from water in coagulation process.

    PubMed

    Kaleta, Jadwiga; Elektorowicz, Maria

    2013-01-01

    This paper presents the results of a laboratory study on the effectiveness of the coagulation process in removing surfactants from water. The application of traditional coagulants (aluminium sulfate and iron chlorides) has not brought satisfactory results, the reduction in anionic surfactant (AS) content reached 7.6% and 10%, respectively. Adding cationic polyelectrolyte (Zetag-50) increased the removal efficiency to 24%. Coagulation using a polyelectrolyte alone proved to be more efficient, the reduction in surfactant content fluctuated at a level of about 50%. Complete surfactant removal was obtained when powdered activated carbon was added 5 minutes before the basic coagulant to the coagulation process. The efficiency of surfactant coagulation also increased after the application of powdered clinoptilolite, but to a smaller degree. Then the removal of AS was found to be improved by dosing powdered clinoptilolite simultaneously or with short delay after the addition of the basic coagulant. PMID:23837351

  12. 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.

  13. 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. PMID:25362971

  14. Coagulant Activity of Leukocytes. TISSUE FACTOR ACTIVITY

    PubMed Central

    Niemetz, J.

    1972-01-01

    Peritoneal leukocytes harvested from rabbits which have received two spaced doses of endotoxin have significantly greater (10-fold) coagulant activity than leukocytes from control rabbits. The coagulant activity accelerates the clotting of normal plasma and activates factor X in the presence of factor VII and calcium and is therefore regarded as tissue factor. A total of 40-80 mg tissue factor activity was obtained from the peritoneal cavity of single endotoxin-treated rabbits. In leukocyte subcellular fractions, separated by centrifugation, the specific tissue factor activity sedimented mainly at 14,500 g and above. The procoagulant activity was destroyed after heating for 10 min at 65°C but was preserved at lower temperatures. Polymyxin B, when given with the first dose of endotoxin, reduced both the number of peritoneal leukocytes and their tissue factor activity by two-thirds. When given immediately before the second dose of endotoxin, polymyxin B had no inhibitory effect. PMID:4333021

  15. Disseminated Intravascular Coagulation Induced with Leukocyte Procoagulant

    PubMed Central

    Kociba, Gary J.; Griesemer, Richard A.

    1972-01-01

    The procoagulant activity of rabbit peritoneal leukocytes significantly increased when the leukocytes were incubated in suspension cultures at 37 C for 24 hours. Intravenous infusions of Iysates of 232 × 106 rabbit leukocytes which had been incubated in cultures at 37 C for 24 hours produced disseminated intravascular coagulation and vasculitis involving the pulmonary arteries in normal rabbits. Intraaortic infusions of lysates of 230 × 106 similarly incubated leukocytes produced renal thrombosis and renal cortical necrosis in normal rabbits. These observations suggest that the procoagulant of granulocytic leukocytes could play a role in the generalized Shwartzman reaction and other syndromes of disseminated intravascular coagulation. ImagesFig 3Fig 4Fig 5Fig 6Fig 7Fig 1Fig 2 PMID:5086898

  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

    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.

  18. Microscopic correlates of macroscopic optical property changes during thermal coagulation of myocardium

    NASA Astrophysics Data System (ADS)

    Thomsen, Sharon L.; Jacques, Steven L.; Flock, Stephen T.

    1990-06-01

    The effects of thermal coagulation on the macroscopic optical transport parameters that govern the distribution of light in tissues were studied. The optical absorption coefficients, pa, and the reduced scattering coefficients, j.ts (1-g), were deduced from measurements of total transmission and total reflectance of HeNe laser radiation ( = 633 and 594 nm) directed to thin slices of dog myocardium heated in vitro. The first optical changes were detected at 45°and, at temperatures above 65°, there was a 2-fold increase in absorption and a 7-fold increase in scattering. Transmission electron microscopy of laser-induced thermally coagulated lesions in rat myocardium (cw argon ion, = 514 nm) revealed ultrastructural alterations that were considered responsible for the increased scattering based on Mie theory. These microscopic alterations included disruption of mitochondria to form aggregates of electron dense granules and granular transformation of thermally coagulated proteins of the sarcomeres and cytoplasm. Our preliminary analyses suggest that the mitochondrial granules and the protein granules contribute to the increased scattering oflight in thermally coagulated myocardium.

  19. 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. PMID:25909013

  20. 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

  1. 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.

  2. 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.

  3. 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. PMID:22525456

  4. A novel coagulation inhibitor from Schistosoma japonicum.

    PubMed

    Ranasinghe, Shiwanthi L; Fischer, Katja; Gobert, Geoffrey N; McManus, Donald P

    2015-12-01

    Little is known about the molecular mechanisms whereby the human blood fluke Schistosoma japonicum is able to survive in the host venous blood system. Protease inhibitors are likely released by the parasite enabling it to avoid attack by host proteolytic enzymes and coagulation factors. Interrogation of the S. japonicum genomic sequence identified a gene, SjKI-1, homologous to that encoding a single domain Kunitz protein (Sjp_0020270) which we expressed in recombinant form in Escherichia coli and purified. SjKI-1 is highly transcribed in adult worms and eggs but its expression was very low in cercariae and schistosomula. In situ immunolocalization with anti-SjKI-1 rabbit antibodies showed the protein was present in eggs trapped in the infected mouse intestinal wall. In functional assays, SjKI-1 inhibited trypsin in the picomolar range and chymotrypsin, neutrophil elastase, FXa and plasma kallikrein in the nanomolar range. Furthermore, SjKI-1, at a concentration of 7·5 µ m, prolonged 2-fold activated partial thromboplastin time of human blood coagulation. We also demonstrate that SjKI-1 has the ability to bind Ca(++). We present, therefore, characterization of the first Kunitz protein from S. japonicum which we show has an anti-coagulant properties. In addition, its inhibition of neutrophil elastase indicates SjKI-1 have an anti-inflammatory role. Having anti-thrombotic properties, SjKI-1 may point the way towards novel treatment for hemostatic disorders. PMID:26463744

  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. 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. PMID:19516255

  7. 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.

  8. [Progress in research of the blood coagulation system].

    PubMed

    Urano, H; Karasaki, Y; Shirahata, A

    1999-09-01

    Blood coagulation is an amplification system consisting of reactions between enzymes and zymogens. It has been illustrated as a cascade model. However, the exact mechanism by which haemostasis is achieved under physiological conditions remains to be clarified. The solving of structure-function relation of each coagulation factor, analysis of the enzymological characteristics of each reaction, analysis of the regulation mechanism of the reactions and identification of novel factors involved in coagulation reactions contribute to the understanding of this complex system. Based on these findings, some new conceptions of blood coagulation are proposed. In the model introduced in this review, the extrinsic pathway and the intrinsic pathway of the 'classical' cascade model of the blood coagulation system could not be separated, and the suppression of fibrinolysis by TAFI (thrombin activatable fibrinolysis inhibitor) during coagulation reactions is thought to be a critical process for effective haemostasis. PMID:10589463

  9. 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.

  10. 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.

  11. 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%. PMID:25084418

  12. Study on coagulation property of metal-polysilicate coagulants in low turbidity water treatment.

    PubMed

    Yang, Hai-yan; Cui, Fu-yi; Zhao, Qing-liang; Ma, Chao

    2004-06-01

    In order to remove the low turbidity present in surface water, a novel metal-polysilicate coagulant was used to treat the raw water taken from Tanjiang River in Guangdong Province. This study on the effects of Al/Fe molar ratio on the performance of a complex compound formed by polysilicic acid, aluminium and ferric salt (PAFS) showed that PAFS with Al/Fe ratio of 10:3 seemed to have the best coagulation performance in removing turbidity and color. Experimental results showed that under the conditions of polymerization time of 15 d, sedimentation time of 12 min, and pH of 6-8, PAFS with Al/Fe molar ratio of 10:3 had the best coagulation efficiency and lowest residual Al concentration. The turbidity decreased from 23.8 NTU to 3.23 NTU and the residual Al concentration was only 0.165 mg/L in the product water. It could be speculated that colloidal impurities and particulate Al were removed by adsorption bridging and electrical neutralization of long chain inorganic polymer coagulants. PMID:15101109

  13. Coagulation disorders and their cutaneous presentations: Pathophysiology.

    PubMed

    Chang, Yunyoung; Dabiri, Ganary; Damstetter, Elizabeth; Baiyee Ebot, Emily; Powers, Jennifer Gloeckner; Phillips, Tania

    2016-05-01

    Hypercoagulable states are inherited or acquired predispositions to venous or arterial thromboses that are best understood in the context of the coagulation cascade. Dermatologists can play a critical role in diagnosing and treating patients with hypercoagulable states because cutaneous symptoms may be a presenting manifestation, thereby reducing morbidity and mortality related to these conditions. This review focuses on the epidemiology and pathophysiology of hypercoagulable states, while the accompanying article iterates the basic clinical features, diagnostic testing, and management of patients who have these conditions. PMID:27085225

  14. Preparation and coagulation efficiency of polyaluminium ferric silicate chloride composite coagulant from wastewater of high-purity graphite production.

    PubMed

    Niu, Xiaoxia; Li, Xili; Zhao, Jihong; Ren, Yigang; Yang, Yanqin

    2011-01-01

    The aim of the present work was to produce a polyaluminium ferric silicate chloride (PAFSiC) coagulant from acidic and alkaline wastewater of purifying graphite by roasting, and subsequently to evaluate coagulation efficiency of the reagent by treating surface water from the Yellow River as well as municipal wastewater in comparison with the conventional coagulant polyaluminium chloride (PAC). The PAFSiC coagulant was prepared by co-polymerization. The effects of (Al+Fe)/Si molar ratio, OH/(Al+Fe) molar ratio (i.e., y value), coagulant dosage and pH value of test suspension on the coagulation behavior of FAFSiC and the stability of the PAFSiC were also examined. Results showed that PAFSiC performed more efficiently than PAC in removing turbidity, chemical oxygen demand (COD), and total phosphate (TP). The PAFSiC with a y value of 2.0 and (Al+Fe)/Si ratio of 5 (PAFSiC 2.0/5) showed excellent coagulation effect for both turbidity and COD, while PAFSiC 1.0/5 was the best for TP. The optimum coagulation pH range of PAFSiC 2.0/5 was 5.0-9.0, slightly wider than that of PAC (6.0-8.0). The process can be easily incorporated into high-purity graphite production plants, thereby reducing wastewater pollution and producing a valuable coagulant. PMID:22125904

  15. 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.

  16. 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

  17. Histology assessment of bipolar coagulation and argon plasma coagulation on digestive tract

    PubMed Central

    Garrido, Teresa; Baba, Elisa R; Wodak, Stephanie; Sakai, Paulo; Cecconello, Ivan; Maluf-Filho, Fauze

    2014-01-01

    AIM: To analyze the effect of bipolar electrocoagulation and argon plasma coagulation on fresh specimens of gastrointestinal tract. METHODS: An experimental evaluation was performed at Hospital das Clinicas of the University of São Paulo, on 31 fresh surgical specimens using argon plasma coagulation and bipolar electrocoagulation at different time intervals. The depth of tissue damage was histopathologically analyzed by single senior pathologist unaware of the coagulation method and power setting applied. To analyze the results, the mucosa was divided in superficial mucosa (epithelial layer of the esophagus and superficial portion of the glandular layer of the stomach and colon) intermediate mucosa (until the lamina propria of the esophagus and until the bottom of the glandular layer of the stomach and colon) and muscularis mucosa. Necrosis involvement of the layers was compared in several combinations of power and time interval. RESULTS: Involvement of the intermediate mucosa of the stomach and of the muscularis mucosa of the three organs was more frequent when higher amounts of energy were used with argon plasma. In the esophagus and in the colon, injury of the intermediate mucosa was frequent, even when small amounts of energy were used. The use of bipolar electrocoagulation resulted in more frequent involvement of the intermediate mucosa and of the muscularis mucosa of the esophagus and of the colon when higher amounts of energy were used. In the stomach, these involvements were rare. The risk of injury of the muscularis propria was significant only in the colon when argon plasma coagulation was employed. CONCLUSION: Tissue damage after argon plasma coagulation is deeper than bipolar electrocoagulation. Both of them depend on the amount of energy used. PMID:25031789

  18. 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. PMID:26521220

  19. Development and experimental in-vivo evaluation of mathematical modeling of coagulation by laser

    NASA Astrophysics Data System (ADS)

    Beacco, Claire; Mordon, Serge R.; Brunetaud, Jean Marc

    1992-08-01

    Most clinical procedures using lasers are based on thermal laser-tissue interactions resulting in tissue damage. A mathematical model allowing temperature and damage prediction would be a useful tool to choose laser parameters able to produce the damage required. This study aimed at the development of a model called HELIOS. The capability of the model to predict thermal coagulation was evaluated by comparison with experimental in-vivo results. Conversion of laser light in tissue was studied using a beam broadening model, which is typically a modification of Beer-Lambert's law and takes into account scattering of light in tissue. HELIOS was validated making experimental studied in-vivo on liver (homogeneous tissue) of rats using a CW Nd:YAG laser, a CO2 laser, and an Argon laser. For a given set of laser parameters, temperature measurements were performed using an infrared camera (Agema, Sweden). The histological examination was carried out on samples to quantify the depth of coagulation necrosis. Experimental data obtained in-vivo were compared with those calculated previously using HELIOS and similar sets of parameters. The difference between the predicted temperature evolution on tissue surface and that measured by the infrared camera was less than 5 degree(s)C in all cases. The difference between the predicted coagulation necrosis depth and the corresponding experimental one was less than 10%. In conclusion, HELIOS allows good prediction of tissue temperature and coagulation necrosis. This model appears sufficiently precise for clinical applications and so should be well adapted to control thermal action of lasers in biological tissues.

  20. Contact Activation of Blood Plasma Coagulation

    PubMed Central

    Vogler, Erwin A.; Siedlecki, Christopher A.

    2009-01-01

    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→surfaceFXIIa, 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 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. PMID:19168215

  1. 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.

  2. 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

  3. Coagulation parameters in inflammatory bowel disease

    PubMed Central

    Dolapcioglu, Can; Soylu, Aliye; Kendir, Tulin; Ince, Ali Tuzun; Dolapcioglu, Hatice; Purisa, Sevim; Bolukbas, Cengiz; Sokmen, Haci Mehmet; Dalay, Remzi; Ovunc, Oya

    2014-01-01

    Thromboembolic events represent a major cause of morbidity and mortality in patients with inflammatory bowel disease and they may occur both at the gastrointestinal tract and at extraintestinal sites. This study aimed to examine the alterations in coagulation parameters involved at different steps of hemostasis in patients with Crohn’s disease and ulcerative colitis, in comparison with healthy individuals. Fifty-one patients with inflammatory bowel disease and 26 healthy controls were included in this study. Plasma levels of PT, APTT, AT III, plasminogen, fibrinogen, D-dimer, factor V, factor VIII, protein C, protein S, and APCR were measured and factor V Leiden mutation was examined in both patients and controls. Two patients with ulcerative colitis had a history of previous thromboembolic event. Inflammatory bowel disease was associated with significantly higher levels of fibrinogen, PT, factor V, factor VIII, plasminogen and thrombocyte. Protein S, fibrinogen, plasminogen and thrombocyte levels were associated with disease activity, depending on the type of the disease (Crohn’s disease or ulcerative colitis). The coagulation abnormalities detected in this study seems to be a secondary phenomena resulting from the disease process, which is more likely to be associated with a multitude of factors rather than a single abnormality. PMID:24995109

  4. Evaluation of natural coagulants for direct filtration.

    PubMed

    Mandloi, M; Chaudhari, S; Folkard, G K

    2004-04-01

    In the present study surjana (Moringa oleifera) seed, maize (Zea mays) and chitosan were used in direct filtration of Bilaoli lake water and evaluated for their efficiency in removing turbidity and microorganisms from water. The experiments with these natural coagulants gave filtered water turbidity less than or almost equal to 1NTU and thereby met the turbidity criteria for drinking water as per WHO guidelines. Bilaoli lake water had low ionic strength and low turbidity which represents one of the most difficult raw waters to treat, but natural coagulants in direct filtration achieved good filtrate quality. The head loss development across the filter bed with chitosan was more than that of alum, while with maize it was comparable to that of alum. With M. oleifera seeds the head loss was much less in comparison to alum. The average most probable number (MPN) reductions obtained with M. oleifera seeds, maize and chitosan were 97.35%, 95.4% and 87.1% respectively, whereas, with alum it was only 7.7%. PMID:15214453

  5. Perioperative coagulation management--fresh frozen plasma.

    PubMed

    Kor, Daryl J; Stubbs, James R; Gajic, Ognjen

    2010-03-01

    Clinical studies support the use of perioperative fresh frozen plasma (FFP) in patients who are actively bleeding with multiple coagulation factor deficiencies and for the prevention of dilutional coagulopathy in patients with major trauma and/or massive haemorrhage. In these settings, current FFP dosing recommendations may be inadequate. However, a substantial proportion of FFP is transfused in non-bleeding patients with mild elevations in coagulation screening tests. This practice is not supported by the literature, is unlikely to be of benefit and unnecessarily exposes patients to the risks of FFP. The role of FFP in reversing the effects of warfarin anticoagulation is dependent on the clinical context and availability of alternative agents. Although FFP is commonly transfused in patients with liver disease, this practice needs broad reconsideration. Adverse effects of FFP include febrile and allergic reactions, transfusion-associated circulatory overload and transfusion-related acute lung injury. The latter is the most serious complication, being less common with the preferential use of non-alloimmunised, male-donor predominant plasma. FP24 and thawed plasma are alternatives to FFP with similar indications for administration. Both provide an opportunity for increasing the safe plasma donor pool. Although prothrombin complex concentrates and factor VIIa may be used as alternatives to FFP in a variety of specific clinical contexts, additional study is needed. PMID:20402170

  6. Disseminated Intravascular Coagulation Syndromes in Obstetrics.

    PubMed

    Cunningham, F Gary; Nelson, David B

    2015-11-01

    Disseminated intravascular coagulation (DIC) is a syndrome that can be initiated by a myriad of medical, surgical, and obstetric disorders. Also known as consumptive coagulopathy, DIC is a common contributor to maternal morbidity and mortality and is associated with up to 25% of maternal deaths. The etiopathogenesis of DIC is complex and currently thought to be initiated by tissue factor or thromboplastin, which is released from trophoblastic or fetal tissue, or maternal decidua or endothelium. Tissue factor activates the coagulation sequence to cause fibrin clotting and its dissolution by the fibrinolysin system. The result of this process can range from mild, clinically insignificant laboratory derangements to marked coagulopathy with bleeding at sites of minimal trauma. Although clinical recognition varies by disease severity, several organizations have attempted to standardize the diagnosis through development of scoring systems. Several important--albeit not necessarily common--obstetric disorders associated with DIC include placental abruption, amniotic fluid embolism, sepsis syndrome, and acute fatty liver of pregnancy. More common disorders include severe preeclampsia, hemolysis, elevated liver enzymes, and low platelet count syndrome, and massive obstetric hemorrhage. Importantly, many of these disorders either cause or are associated with substantive obstetric hemorrhage. Treatment of DIC is centered on two principles. The first is identification and treatment of the underlying disorder. Because many women with consumptive coagulopathy also have massive hemorrhage, the second tenet of treatment is that obstetric complications such as uterine atony or lacerations must be controlled simultaneously with prompt blood and component replacement for a salutary outcome. PMID:26444122

  7. 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...

  8. 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.

  9. 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.

  10. 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. PMID:26490941

  11. Assessment of Coagulation and Fibrinolysis in Pre-eclampsia

    PubMed Central

    Wood, S. M.; Burnett, D.; Picken, A. M.; Farrell, G. W.; Wolf, P.

    1974-01-01

    A method is described for distinguishing coagulation from fibrinolysis by three estimates of fibrinogen. This “fibrinogen series” together with plasma antithrombin and urinary urokinase have been compared in pregnant patients with venous thrombosis and pre-eclampsia. Evidence is presented for active coagulation during deterioration of the pre-eclampsia state and for enhanced fibrinolysis during improvement. PMID:4596483

  12. 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.

  13. 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.

  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. PMID:26897520

  15. 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

  16. 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

  17. Quinine-Induced Disseminated Intravascular Coagulation.

    PubMed

    Abed, Firas; Baniya, Ramkaji; Bachuwa, Ghassan

    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

  18. Optimized alumina coagulants for water treatment

    SciTech Connect

    Nyman, May D.; Stewart, Thomas A.

    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+.

  19. Application of enzyme immunoassays to coagulation testing.

    PubMed

    Amiral, J; Adalbert, B; Adam, M

    1984-09-01

    Enzyme immunoassays are very useful for the detection of low concentrations of coagulation proteins and pathological markers in plasma. Analytes in the ng/mL range are measurable with good reproducibility with intra- and interassay CVs of less than 5% to 10%. "Sandwich" methods have been developed for von Willebrand factor (plasma concentration about 8 micrograms/mL, Factor IX (5 micrograms/mL), protein C (4 micrograms/mL), and Factor X (10 micrograms/mL). However, this technique is only suitable for macromolecules; for low-molecular-mass peptides such as fibrinopeptide A a competitive method is used. Normal concentrations of fibrinopeptide A are below 3 ng/mL, with greater values suggesting in vivo generation of thrombin; thus this test is quite useful in detecting thrombosis. Reagents for both the sandwich and competitive methods are commercially available and cost effective, and have a longer shelf-life than those for radioimmunoassays. PMID:6380814

  20. 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.

  1. Field-theory methods in coagulation theory

    NASA Astrophysics Data System (ADS)

    Lushnikov, A. A.

    2011-08-01

    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 1, n 2, ..., n g , ...}, where n g is the total number of particles containing precisely g monomers. Thereupon, one introduces the generating functional Ψ for the probability W( Q, t). The time evolution of Ψ is described by an equation that is similar to the Schrödinger 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.

  2. Chemical behavior of different species of phosphorus in coagulation.

    PubMed

    Park, Taejun; Ampunan, Vanvimol; Lee, Sanghyup; Chung, Eunhyea

    2016-02-01

    Phosphorus is one of the elements that have a significant impact on such environmental problems as eutrophication or algal bloom. Phosphorus compounds in water can be hydrolyzed to orthophosphate that is the only form of phosphorus that algae can assimilate. In this study, phosphorus removal in terms of orthophosphate and total phosphorus from wastewater was studied using alum or ferric ions as coagulants. It was observed that alum shows higher phosphorus removal efficiency than ferric ions in the same mole ratio concentrations. The proportion of orthophosphate among total phosphorus did not change significantly during coagulation process when the coagulant concentration is low. However, the proportion becomes gradually decreased as the coagulant concentration increases. Not only the electrolyte concentration difference in solution, but the characteristics of orthophosphate and polyphosphate such as reactivity and ionic size might also cause the differences in the removal rate. Orthophosphate that has greater reactivity than other phosphorus species would be involved in chemical reactions dominantly when large amounts of coagulants are applied. However, the effect of reactivity was diminished due to the large ionic size of polyphosphate and low concentration of electrolyte in low coagulant concentration during the coagulation process. PMID:26598995

  3. Seawater pretreatment for reverse osmosis: chemistry, contaminants, and coagulation.

    PubMed

    Edzwald, James K; Haarhoff, Johannes

    2011-11-01

    The paper addresses the effects of salinity and temperature on the chemistry of important parameters affecting coagulation pretreatment including the ion product of water, acid-base chemistry, dissolved metal speciation, and precipitation reactions for aluminum and iron coagulants. The ion product of seawater is greater than for freshwaters and affects chemical hydrolysis and metal-hydroxide solubility reactions. Inorganic carbon is the main cause of seawater alkalinity and buffer intensity but borate B(OH)(4)(1-) also contributes. Buffer intensity is an important parameter in assessing coagulation pH adjustment. Mineral particles are relatively unstable in seawater from electrical double layer compression, and when present these particles are easily coagulated. Algal-particle stability is affected by steric effects and algal motility. Dissolved natural organic matter from algae and humic substances causes fouling of RO membranes and pretreatment removal is essential. Aluminum coagulants are not recommended, and not used, because they are too soluble in seawater. Ferric coagulants are preferred and used. The equilibrium solubility of Fe with amorphous ferric hydroxide in seawater is low over a wide range of pH and temperature conditions. Ferric chloride dosing guidelines are presented for various raw seawater quality characteristics. The effect of pH on coagulant dose and the role of buffer intensity are addressed. A dual coagulation strategy is recommended for treating seawater with moderate to high concentrations of algae or seawater with humic matter. This involves a low and constant dose with high charge-density cationic polymers using Fe as the main coagulant where it is varied in response to raw water quality changes. PMID:21907384

  4. 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.

  5. 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. PMID:27295439

  6. 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. PMID:26574522

  7. 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...

  8. Complement-coagulation crosstalk on cellular and artificial surfaces.

    PubMed

    Wiegner, Rebecca; Chakraborty, Shinjini; Huber-Lang, Markus

    2016-10-01

    The humoral serine proteases of the complement system and the coagulation system play central roles during the events of an inflammatory response. While the complement system confers immunoprotective and -regulatory functions, the coagulation cascade is responsible to ensure hemostatic maintenance. Although these two systems individually unfold during inflammation, several studies have reported on the "crosstalk" between components of the complement and the coagulation system in the fluid phase. However, both cascades are usually initiated on or in close proximity to foreign or activated surfaces, and there is increasing evidence for interacting complement and coagulation proteins on various superficial areas on endothelium, circulating entities like platelets, leukocytes, microparticles and pathogens, and even on artificial surfaces. This review aims at summarizing these interactions to complete the picture. PMID:27371975

  9. Bak-Sneppen Type Models and Coagulation-Fragmentation Processes

    NASA Astrophysics Data System (ADS)

    Grinfeld, M.

    2008-09-01

    We suggest a construction that allows us to bring methods of denumerable Markov chain theory and coagulation-fragmentation processes to bear on the question of locating the threshold in Bak-Sneppen type models.

  10. Argon beam coagulation in foot and ankle surgery.

    PubMed

    Adams, Melissa L; Steinberg, John S

    2011-01-01

    In this brief report, we introduce the principles, indications, advantages, disadvantages, and surgical techniques involved in the use of argon beam coagulation in foot and ankle surgery. PMID:21907597

  11. 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. PMID:23109567

  12. Moringa coagulant as a stabilizer for amorphous solids: Part I.

    PubMed

    Bhende, Santosh; Jadhav, Namdeo

    2012-06-01

    Stabilization of amorphous state is a focal area for formulators to reap benefits related with solubility and consequently bioavailability of poorly soluble drugs. In the present work, an attempt has been made to explore the potential of moringa coagulant as an amorphous state stabilizer by investigating its role in stabilization of spray-dried (amorphous) ibuprofen, meloxicam and felodipine. Thermal studies like glass forming ability, glass transition temperature, hot stage microscopy and DSC were carried out for understanding thermodynamic stabilization of drugs. PXRD and dissolution studies were performed to support contribution of moringa coagulant. Studies showed that hydrogen bonding and electrostatic interactions between drug and moringa coagulant are responsible for amorphous state stabilization as explored by ATR-FTIR and molecular docking. Especially, H-bonding was found to be predominant mechanism for drug stabilization. Therein, arginine (basic amino acid in coagulant) exhibited various interactions and played important role in stabilization of aforesaid amorphous drugs. PMID:22359158

  13. Disseminated intravascular coagulation and hepatocellular necrosis due to clove oil.

    PubMed

    Brown, S A; Biggerstaff, J; Savidge, G F

    1992-10-01

    We describe the case of a 2-year-old child who suffered from disseminated intravascular coagulation (DIC) and hepatocellular necrosis, following ingestion of clove oil. The patient was treated with heparin and fresh frozen plasma, and, following specific haemostasis assays, with appropriate coagulation factor and inhibitor concentrates. The case demonstrates how this approach can be successfully used in the management of DIC with coexisting liver failure. PMID:1450336

  14. 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.

  15. Gastric explosion induced by argon plasma coagulation and prevention strategies.

    PubMed

    Freiman, John Saul; Hampe, Toni

    2014-12-01

    We describe the occurrence of an iatrogenic explosion induced by argon plasma coagulation in a 70-year-old man undergoing gastroscopy. Combustible gases in the stomach may have been released by bacterial overgrowth as a result of partial gastric outlet obstruction (caused by a gastric tumor) and reduced acidity (from proton pump inhibitor therapy). We propose a stepwise process during upper endoscopy to prevent this devastating complication, comprising aspiration, preinsufflation with CO2, and then coagulation. PMID:25041867

  16. 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

  17. 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. PMID:23513676

  18. 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.

  19. 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. PMID:23170793

  20. 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.

  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. Influence of blood coagulability after spinal surgeries

    PubMed Central

    Matsumoto, Marcelo Hide; Rodrigues, Luiz Claudio Lacerda; Batalini, Luiz Gustavo da silva; Fonteles, Thales Arcanjo; Bortoletto, Adalberto

    2014-01-01

    Objective: To verify whether spinal surgery causes relevant changes in the blood clotting process and define which factors have the greatest influence on changes found. Method: This is a not randomized, cross-sectional study, Forty seven patients were evaluated between August 2011 and February 2013, whose clinical, surgical, laboratory and image daata were collected. The data obtained were crossed with the epidemiological data of each patient in a moment prior to and another after surgery searching which variables have been directly influenced. Result: Our analysis showed that the most important changes occurred in patients with BMI classified, according to the World Health Organization (WHO) as out of healthy range. Other smaller correlations were also found. Another important consideration was the tendency to observe hypercoagulability in smoker patients, a fact that is not influenced by spinal procedures. Conclusion: We concluded that spinal surgeries cause few relevant changes in the blood clotting process and that among the factors studied, BMI (when out of the healthy range, according to the WHO classification) showed closer relationship with changes in laboratory coagulation tests. Level of Evidence III, Cross-Sectional Study. PMID:25328429

  3. Disseminated intravascular coagulation following administration of sunitinib

    PubMed Central

    OLIVO, ANAËLLE; NOËL, NICOLAS; BESSE, BENJAMIN; TABURET, ANNE-MARIE; LAMBOTTE, OLIVIER

    2016-01-01

    Sunitinib is an increasingly used, orally administered targeted therapy, approved by the European Medicines Agency for the treatment of various types of cancer, including gastrointestinal stromal tumor unresectable or metastatic disease, following disease progression or intolerance to imatinib, and advanced or metastatic renal cell carcinoma, progressive well-differentiated pancreatic neuroendocrine tumors in patients with unresectable, locally advanced or metastatic disease. Sunitinib inhibits several tyrosine kinases, including the vascular endothelial growth factor receptor and the platelet-derived growth factor receptor. Tyrosine kinases inhibitor therapies are generally well-tolerated; nonetheless, they are not void of side effects. The majority of patients reported are grade 1 or 2, and include common and unspecific adverse events, including fatigue, gastrointestinal disorders, skin discoloration, altered taste, cough and dyspnea. Grade 3 or 4 adverse events, including bleeding and hemorrhage, are less frequent. The present study presented the first case of disseminated intravascular coagulation associated with the administration of sunitinib, shortly following the increase of sunitinib dosage. PMID:27330781

  4. 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

  5. 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. PMID:27401835

  6. Floc characterization and membrane fouling of polyferric-polymer dual/composite coagulants in coagulation/ultrafiltration hybrid process.

    PubMed

    Rong, Hongyan; Gao, Baoyu; Li, Junchao; Zhang, Bei; Sun, Shenglei; Wang, Yan; Yue, Qinyan; Li, Qian

    2013-12-15

    Papermaking sludge and spent pickling liquor were recycled to synthesize a macromolecular lignin-acrylamide polymer (LA) and polyferric chloride (PFC), respectively. The dual-coagulant PFC-LA (PFC and LA were dosed orderly), composite coagulant PFCLA (PFC and LA premixed before dosed) and PFC were used in coagulation/ultrafiltration hybrid process in surface water treatment. The objectives of this paper are to comparatively investigate final water quality after coagulation and coagulation/ultrafiltration process and floc properties, including floc size, strength, recoverability and floc structure, with or without LA addition. Additionally, the relationship between membrane fouling and floc characteristics was discussed. The results showed that best final water quality was obtained by PFC-LA, sequentially followed by PFCLA and PFC. Floc size, growth rate, strength and recoverability as well as fractal dimension were also in the order of PFC-LA>PFCLA>PFC. The maximum permeate fluxes before and after backwash operation were obtained by PFC-LA, which gave the largest and most compact flocs. Coagulation suspension after breakage resulted in much more serious membrane fouling for PFC, whereas permeate flux slightly decreased when LA was used in combination with PFC. PMID:24144372

  7. 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. PMID:26026608

  8. 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.

  9. Effect of nano-scale curvature on the intrinsic blood coagulation system

    NASA Astrophysics Data System (ADS)

    Kushida, Takashi; Saha, Krishnendu; Subramani, Chandramouleeswaran; Nandwana, Vikas; Rotello, Vincent M.

    2014-11-01

    The intrinsic coagulation activity of silica nanoparticles strongly depends on their surface curvature. Nanoparticles with higher surface curvature do not denature blood coagulation factor XII on its surface, providing a coagulation `silent' surface, while nanoparticles with lower surface curvature show denaturation and concomitant coagulation.The intrinsic coagulation activity of silica nanoparticles strongly depends on their surface curvature. Nanoparticles with higher surface curvature do not denature blood coagulation factor XII on its surface, providing a coagulation `silent' surface, while nanoparticles with lower surface curvature show denaturation and concomitant coagulation. Electronic supplementary information (ESI) available: Physical properties and scanning electron micrographs (SEM) of silica NPs, intrinsic coagulation activity after 3 h. See DOI: 10.1039/c4nr04128c

  10. A quantitative comparison between electrocoagulation and chemical coagulation for boron removal from boron-containing solution.

    PubMed

    Yilmaz, A Erdem; Boncukcuoğlu, Recep; Kocakerim, M Muhtar

    2007-10-22

    This paper provides a quantitative comparison of electrocoagulation and chemical coagulation approaches based on boron removal. Electrocoagulation process delivers the coagulant in situ as the sacrificial anode corrodes, due to a fixed current density, while the simultaneous evolution of hydrogen at the cathode allows for pollutant removal by flotation. By comparison, conventional chemical coagulation typically adds a salt of the coagulant, with settling providing the primary pollutant removal path. Chemical coagulation was carried out via jar tests using aluminum chloride. Comparison was done with the same amount of coagulant between electrocoagulation and chemical coagulation processes. Boron removal obtained was higher with electrocoagulation process. In addition, it was seen that chemical coagulation has any effect for boron removal from boron-containing solution. At optimum conditions (e.g. pH 8.0 and aluminum dose of 7.45 g/L), boron removal efficiencies for electrocoagulation and chemical coagulation were 94.0% and 24.0%, respectively. PMID:17524554

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

    PubMed

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

    2015-10-01

    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. PMID:26368847

  12. 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.

  13. 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. PMID:27153238

  14. Polymorphisms of the coagulation system and risk of cancer.

    PubMed

    Tinholt, Mari; Sandset, Per Morten; Iversen, Nina

    2016-04-01

    Hypercoagulability is a frequently finding in patients with cancer, and is associated with an increased risk of venous thrombosis (VT). Cancer-associated VT is associated with poor prognosis and represents the leading non-cancer cause of death among these patients. Conversely, patients experiencing VT are at increased risk of subsequent cancer, suggesting an epidemiological bidirectional link between cancer and hemostasis, and indicating a role of the hemostatic system in cancer development. How the coagulation system relates to cancer etiology at the genetic level is largely unexplored. Data on the association of polymorphisms in genes involved in coagulation with cancer development is important to clarify the role of the coagulation system in cancer pathogenesis. Effects of coagulation-related gene polymorphisms on cancer risk may possibly be translated into novel treatment- and prevention strategies of cancer-associated thrombosis and the cancer itself. This article reviews the current knowledge of the relation between polymorphisms in genes involved in coagulation and cancer risk in solid tumors. PMID:27067978

  15. Effects of Erwinia-asparaginase on the coagulation system.

    PubMed

    Carlsson, H; Stockelberg, D; Tengborn, L; Braide, I; Carneskog, J; Kutti, J

    1995-11-01

    L-Asparaginase treatment during induction therapy in acute lymphoblastic leukaemia (ALL) is known to be frequently complicated by thromboembolic events. It was recently suggested that L-asparaginase derived from Erwinia chrysanthemi alters the coagulation system less severely than does Escherichia coli asparaginase. In a series of 11 adult patients with ALL, we investigated some parameters of the coagulation system during treatment with Erwinia asparaginase. The doses employed were rather high; all patients below the age of 60 years received 15,000 U/m2 daily over 14 days. In accordance with what is known from treatment with E. coli asparaginase, we observed significant lowering of antithrombin as well as of fibrinogen. However, as to fibrinogen indeed a significant decrease had occurred prior to the institution of Erwinia asparaginase treatment. The most striking observation in the present study was that the levels of prothrombin complex, reflecting the function of K-vitamin dependent coagulation factors II, VII and X, remained within normal ranges during treatment. This indicates that these coagulation factors were not affected by Erwinia asparaginase, an observation at variance with several reports where E. coli asparaginase was investigated. This latter observation was the only finding which could lend support to the view that Erwinia asparaginase affects the coagulation system less than E. coli asparaginase. Finally, one of our patients developed a sinus thrombosis, a severe thrombotic complication. PMID:7493674

  16. 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.

  17. 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. PMID:21163511

  18. Disseminated intravascular coagulation in cattle with abomasal displacement.

    PubMed

    Irmak, K; Turgut, K

    2005-01-01

    The purpose of the study was to evaluate haemostatic function in cattle with abomasal displacement (AD) and to reflect the occurrence of disseminated intravascular coagulation (DIC). Ten adult cattle with left displacement of abomasum (LDA) (group I), 10 adult cattle with right displacement of abomasum with volvulus (RDA) (group II) and 10 clinically healthy adult cattle (control group) were used as material. Numbers of platelets (PLT) and coagulation tests (activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), serum fibrin/fibrinogen degradation products (FDPs), fibrinogen) were measured before the surgical treatment of cattle with LDA and RDA. APTT was prolonged only in group II compared with the control and group I (p<0.05). However, when the individual values of coagulation profiles of each cow were evaluated, two cattle in group I and three cattle in group II had at least three abnormal coagulation profiles, which reflect the occurrence of DIC. These cattle died after surgical treatment. The two cattle with LDA had abnormal APTT, FDPs and PLT values; three cattle with RDA had abnormal APTT, PT, TT, FDPs and PLT values. APTT (5 cases), FDPs (5 cases) and thrombocytopenia (5 cases) were the three most common abnormal tests on coagulation profile in the cattle with LDA and RDA. The results of the study indicate that cattle with AD had a spectrum of haemostatic dysfunction and that DIC was a significant risk factor for mortality. PMID:15727292

  19. 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. PMID:27164876

  20. Direct numerical simulation of turbulent aerosol coagulation

    NASA Astrophysics Data System (ADS)

    Reade, Walter Caswell

    There are numerous systems-including both industrial applications and natural occurring phenomena-in which the collision/coagulation rates of aerosols are of significant interest. Two examples are the production of fine powders (such as titanium dioxide) and the formation of rain drops in the atmosphere. During the last decade, it has become apparent that dense aerosol particles behave much differently in a turbulent fluid than has been previously assumed. Particles with a response time on the order of the small-scale fluid time scale tend to collect in regions of low vorticity. The result is a particle concentration field that can be highly non-uniform. Sundaram and Collins (1997) recently demonstrated the effect that turbulence can have on the particle collision rate of a monodisperse system. The collision rates of finite-inertia particles can be as much as two orders of magnitude greater than particles that precisely follow the fluid streamlines. Sundaram and Collins derived a general collision expression that explicitly accounted for the two phenomena that affect the collision rate-changes in the particle concentration field and changes in the particle relative velocities. The result of Sundaram and Collins has generated further interest in the turbulent-aerosol problem. This thesis shows that, in addition to changing the rate that an aerosol size distribution might form, turbulence has the potential of dramatically changing the shape of the distribution. This result is demonstrated using direct numerical simulation of a turbulent-aerosol system over a wide range of particle parameters, and a moderate range of turbulence levels. Results show that particles with a small (but finite) initial inertia have the greatest potential of forming broad size distributions. The shape of the resulting size distribution is also affected by the initial size of the particles. Observations are explained using the statistics identified by Sundaram and Collins (1997). A major

  1. 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. PMID:27235370

  2. Anti-coagulant therapy with dabigatran for cystic fibrosis patients.

    PubMed

    Bansal, Manvi; Ren, Clement L

    2016-08-01

    Patients with cystic fibrosis (CF) are at increased risk of venous thromboembolism, especially in association with central venous catheter use. Coumarin drugs and low molecular weight heparin are frequently used for anti-coagulant therapy, but are more challenging to administer in CF patients. Dabigatran, an oral thrombin antagonist, is an alternative anti-coagulant medication, but its use in CF has not been reported. We describe our experience in successfully using dabigatran for long-term anti-coagulation therapy in two CF patients. Our experience suggests that dabigatran can serve as an option for anticoagulation therapy in CF. Pediatr Pulmonol. 2016;51:E29-E30. © 2016 Wiley Periodicals, Inc. PMID:27128852

  3. 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

  4. 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.

  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. PMID:27262117

  6. 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. PMID:16854802

  7. 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.

  8. 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.

  9. 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. PMID:26149013

  10. 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

  11. 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. PMID:26497986

  12. Relationships between milk coagulation property traits analyzed with different methodologies.

    PubMed

    Pretto, D; Kaart, T; Vallas, M; Jõudu, I; Henno, M; Ancilotto, L; Cassandro, M; Pärna, E

    2011-09-01

    Milk coagulation properties (MCP) analysis is performed using a wide range of methodologies in different countries and laboratories, using different instruments, coagulant activity in the milk, and type of coagulant. This makes it difficult to compare results and data from different research. The aims of this study were to propose a method for the transformation of values of rennet coagulation time (RCT) and curd firmness (a(30)) and to predict the noncoagulation (NC) probability of milk samples analyzed using different methodologies. Individual milk samples were collected during the morning milking in October 2010 from each of 165 Holstein-Friesian dairy cows in 2 freestall barns in Italy, and sent to 3 laboratories for MCP analysis. For each laboratory, MCP analysis was performed using a different methodology: A, with a computerized renneting meter instrument using 0.051 international milk clotting units (IMCU)/mL of coagulant activity; B, with a Lattodinamografo (Foss-Italia, Padova, Italy) using 0.051 IMCU/mL of coagulant activity; and C, with an Optigraph (Ysebaert, Frépillon, France) using 0.120 IMCU/mL of coagulant activity. The relationships between MCP traits were analyzed with correlation and regression analyses for each pair of methodologies. For each MCP trait, 2 regression models were applied: model 1 was a single regression model, where the dependent and independent variables were the same MCP trait determined by 2 different methodologies; in model 2, both a(30) and RCT were included as independent variables. The NC probabilities for laboratories with the highest number of NC samples were predicted based on the RCT and a(30) values measured in the laboratories with lower number of NC samples using logistic regression and receiver operating characteristic analysis. The percentages of NC samples were 4.2, 11.5, and 0.6% for A, B, and C, respectively. The transformation of MCP traits was more precise with model 1 for RCT (R(2): 0.77-0.82) than for a(30

  13. Two solvable systems of coagulation equations with limited aggregations

    NASA Astrophysics Data System (ADS)

    Bertoin, Jean

    2009-11-01

    We consider two simple models for the formation of polymers where at the initial time, each monomer has a certain number of potential links (called arms in the text) that are consumed when aggregations occur. Loosely speaking, this imposes restrictions on the number of aggregations. The dynamics of concentrations are governed by modifications of Smoluchowski's coagulation equations. Applying classical techniques based on generating functions, resolution of quasi-linear PDE's, and Lagrange inversion formula, we obtain explicit solutions to these non-linear systems of ODE's. We also discuss the asymptotic behavior of the solutions and point at some connexions with certain known solutions to Smoluchowski's coagulation equations with additive or multiplicative kernels.

  14. A review of research on nanoparticulate flow undergoing coagulation

    NASA Astrophysics Data System (ADS)

    Lin, Jianzhong; Huo, Linlin

    2015-06-01

    Nanoparticulate flows occur in a wide range of natural phenomena and engineering applications and, hence, have attracted much attention. The purpose of the present paper is to provide a review of the research conducted over the last decade. The research covered relates to the Brownian coagulation of monodisperse and polydisperse particles, the Taylor-series expansion method of moment, and nanoparticle distributions due to coagulation in pipe and channel flow, jet flow, and the mixing layer and in the process of flame synthesis and deposition.

  15. 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.

  16. 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.

  17. 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. PMID:27033148

  18. Inflammation and the coagulation system in tuberculosis: Tissue Factor leads the dance.

    PubMed

    Caccamo, Nadia; Dieli, Francesco

    2016-02-01

    Mycobacterium tuberculosis, the causative agent of tuberculosis, drives the formation of granulomas, structures in which both immune cells and the bacterial pathogen cohabit. The most abundant cells in granulomas are macrophages, which contribute as both cells with bactericidal activity and as targets for M. tuberculosis infection and proliferation during the entire course of infection. The mechanisms and factors involved in the regulation and control of macrophage microenvironment-specific polarization and plasticity are not well understood, as some granulomas are able to control bacteria growth and others fail to do so, permitting bacterial spread. In this issue of the European Journal of Immunology, Venkatasubramanian et al. [Eur. J. Immunol. 2016. 46: 464-479] show that mice lacking the tissue factor gene in myeloid cells have augmented M. tuberculosis growth and increased inflammation in the lungs. This suggests that tissue factor, an initiator of coagulation, is important for the generation of fibrin, which supports granuloma formation. This article demonstrates for the first time the involvement of tissue factor in inducing effective immunity against M. tuberculosis, and sheds new lights on the complex interplay between host inflammatory response, the coagulation system, and the control of M. tuberculosis infection. PMID:26763085

  19. 21 CFR 878.4400 - Electrosurgical cutting and coagulation device and accessories.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Electrosurgical cutting and coagulation device and....4400 Electrosurgical cutting and coagulation device and accessories. (a) Identification. An electrosurgical cutting and coagulation device and accessories is a device intended to remove tissue and...

  20. 21 CFR 878.4400 - Electrosurgical cutting and coagulation device and accessories.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electrosurgical cutting and coagulation device and....4400 Electrosurgical cutting and coagulation device and accessories. (a) Identification. An electrosurgical cutting and coagulation device and accessories is a device intended to remove tissue and...

  1. 21 CFR 878.4400 - Electrosurgical cutting and coagulation device and accessories.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Electrosurgical cutting and coagulation device and....4400 Electrosurgical cutting and coagulation device and accessories. (a) Identification. An electrosurgical cutting and coagulation device and accessories is a device intended to remove tissue and...

  2. 21 CFR 878.4400 - Electrosurgical cutting and coagulation device and accessories.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Electrosurgical cutting and coagulation device and....4400 Electrosurgical cutting and coagulation device and accessories. (a) Identification. An electrosurgical cutting and coagulation device and accessories is a device intended to remove tissue and...

  3. 21 CFR 878.4400 - Electrosurgical cutting and coagulation device and accessories.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Electrosurgical cutting and coagulation device and....4400 Electrosurgical cutting and coagulation device and accessories. (a) Identification. An electrosurgical cutting and coagulation device and accessories is a device intended to remove tissue and...

  4. 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…

  5. Fragmentation and Coagulation in Supramolecular (Co)polymerization Kinetics

    PubMed Central

    2016-01-01

    The self-assembly of molecular building blocks into one-dimensional supramolecular architectures has opened up new frontiers in materials science. Due to the noncovalent interactions between the monomeric units, these architectures are intrinsically dynamic, and understanding their kinetic driving forces is key to rationally programming their morphology and function. To understand the self-assembly dynamics of supramolecular polymerizations (SP), kinetic models based on aggregate growth by sequential monomer association and dissociation have been analyzed. However, fragmentation and coagulation events can also play a role, as evident from studies on peptide self-assembly and the fact that aggregations can be sensitive to mechanical agitations. Here, we analyze how fragmentation and coagulation events influence SP kinetics by theoretical analysis of self-assembling systems of increasing complexity. Our analysis starts with single-component systems in which aggregates are able to grow via an isodesmic or cooperative nucleation–elongation mechanism. Subsequently, equilibration dynamics in cooperative two-component supramolecular copolymerizations are investigated. In the final part, we reveal how aggregate growth in the presence of competing, kinetically controlled pathways is influenced by fragmentation and coagulation reactions and reveal how seed-induced growth can give rise to block copolymers. Our analysis shows how fragmentation and coagulation reactions are able to modulate SP kinetics in ways that are highly system dependent. PMID:27163054

  6. 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.

  7. 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...

  8. 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. PMID:25799161

  9. 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. PMID:26188702

  10. Blood coagulation and platelet adhesion on polyaniline films.

    PubMed

    Humpolíček, Petr; Kuceková, Zdenka; Kašpárková, Věra; Pelková, Jana; Modic, Martina; Junkar, Ita; Trchová, Miroslava; Bober, Patrycja; Stejskal, Jaroslav; Lehocký, Marián

    2015-09-01

    Polyaniline is a promising conducting polymer with still increasing application potential in biomedicine. Its surface modification can be an efficient way how to introduce desired functional groups and to control its properties while keeping the bulk characteristics of the material unchanged. The purpose of the study was to synthetize thin films of pristine conducting polyaniline hydrochloride, non-conducting polyaniline base and polyaniline modified with poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPSA) and investigate chosen parameters of their hemocompatibility. The modification was performed either by introduction of PAMPSA during the synthesis or by reprotonation of polyaniline base. The polyaniline hydrochloride and polyaniline base had no impact on blood coagulation and platelet adhesion. By contrast, the polyaniline reprotonated with PAMPSA completely hindered coagulation thanks to its interaction with coagulation factors Xa, Va and IIa. The significantly lower platelets adhesion was also found on this surface. Moreover, this film maintains its conductivity at pH of 6, which is an improvement in comparison with standard polyaniline hydrochloride losing most of its conductivity at pH of 4. Polyaniline film with PAMPSA introduced during synthesis had an impact on platelet adhesion but not on coagulation. The combined conductivity, anticoagulation activity, low platelet adhesion and improved conductivity at pH closer to physiological, open up new possibilities for application of polyaniline reprotonated by PAMPSA in blood-contacting devices, such as catheters or blood vessel grafts. PMID:26119372

  11. 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.

  12. On the Fundamental Solution of a Linearized Homogeneous Coagulation Equation

    NASA Astrophysics Data System (ADS)

    Escobedo, Miguel; Velázquez, J. J. L.

    2010-08-01

    We describe the fundamental solution of the equation that is obtained by linearization of the coagulation equation with kernel K( x, y) = ( xy)λ/2, around the steady state f( x) = x -(3+λ)/2 with {λ in (1, 2)} . Detailed estimates on its asymptotics are obtained. Some consequences are deduced for the flux properties of the particles distributions described by such models.

  13. Coagulation disorders in severely and critically injured patients.

    PubMed

    Avikainen, V

    1977-01-01

    Forty-five patients with multiple injuries treated at an intensive care unit were studied prospectively. The patients were divided into two groups: the severely injured (no mortality) and critically injured (56% mortality). Treatment was started within two hours from the accident in all cases. The following coagulation parameters were measured for eight days: euglobulin lysis time (ELT), thromboelastography (TEG), vecalcification time (RECA), partial thromboplastin time (PTT), factor V, factor VIII, Normotest, Thrombotest, thrombin time, fibrinogen and platelets. Severe coagulation disorders were observed in one-third of the patients 12-48 hours after trauma. The abnormalities were more pronounced in patients who had sustained very severe injuries and arrived in a state of shock. The ELT was shortened 0-6 hours after the accident and accelerated coagulation was indicated simultaneously by decreased PTT, RECA, and r-values as well as by elevated Thrombotest and factor VIII values. The factor V and fibrinogen levels were initially lowered. Low platelet values at 2-4 days, prolonged thrombin and r-times, secondary decrease of fibrinogen FV, FVIII, and low Thrombotest values suggested disseminated intravascular coagulation associated with complications, such as fat embolism and "shock lung" syndromes. General bleeding tendency with high mortality was observed in 16% of the patients. PMID:603216

  14. Removal of sulfide, sulfate and sulfite ions by electro coagulation.

    PubMed

    Murugananthan, M; Raju, G Bhaskar; Prabhakar, S

    2004-06-18

    The removal of various species of sulfur from beamhouse of tannery wastewater and also from synthetic samples was studied by electro-flotation technique. Consumable anodes of iron and aluminum and insoluble anode of titanium were tested as anodes. It was found that iron and aluminum anodes were effective for the removal of suspended solids, sulfide, sulfite and sulfate. Progress of simultaneous coagulation of suspended solids during electro-flotation was measured using particle size analysis. Coagulation was found to be essential for effective flotation of suspended solids. Metal ions generated in situ by electrolytic oxidation of anode were found to react with dissolved sulfide ions. Metal sulfides thus formed as colloidal suspension were coagulated and floated simultaneously by hydrogen bubbles generated from cathode. Simultaneous occurrence of precipitation, coagulation and flotation was observed during electro-flotation. X-ray diffraction studies were conducted to identify the nature of sulfide phase formed during electrolytic precipitation. The effect of pH, current density and initial concentration of pollutants was studied and the results are discussed. The removal of sulfite and sulfate ions is explained by zeta-potential measurements. PMID:15177743

  15. 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. PMID:27148711

  16. 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.

  17. 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.

  18. 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.

  19. Reduction of Turbidity of Water Using Locally Available Natural Coagulants

    PubMed Central

    Asrafuzzaman, Md.; Fakhruddin, A. N. M.; Hossain, Md. Alamgir

    2011-01-01

    Turbidity imparts a great problem in water treatment. Moringa oleifera, Cicer arietinum, and Dolichos lablab were used as locally available natural coagulants in this study to reduce turbidity of synthetic water. The tests were carried out, using artificial turbid water with conventional jar test apparatus. Optimum mixing intensity and duration were determined. After dosing water-soluble extracts of Moringa oleifera, Cicer arietinum, and Dolichos lablab reduced turbidity to 5.9, 3.9, and 11.1 nephelometric turbidity unit (NTU), respectively, from 100 NTU and 5, 3.3, and 9.5, NTU, respectively, after dosing and filtration. Natural coagulants worked better with high, turbid, water compare to medium, or low, turbid, water. Highest turbidity reduction efficiency (95.89%) was found with Cicer arietinum. About 89 to 96% total coliform reduction were also found with natural coagulant treatment of turbid water. Using locally available natural coagulants, suitable, easier, and environment friendly options for water treatment were observed. PMID:23724307

  20. Removal of THM precursors by coagulation or ion exchange.

    PubMed

    Bolto, Brian; Dixon, David; Eldridge, Rob; King, Simon

    2002-12-01

    The removal of natural organic matter (NOM) from drinking water supplies can be achieved by different processes, among them coagulation and adsorption. Synthetic waters made from concentrates of humic substances from reservoir and river waters were tested in the laboratory for ease of removAl of NOM by coagulation with cationic organic polymers and with alum, and by adsorption on anion exchangers. For polymers such as high molecular weight polydiallyldimethylammonium chloride (polyDADMAC) and cationic polyacrylamides of high charge, performance was nearly as effective as alum, with colour removals 86-100% of those obtained for alum. Ion exchange using the best commercially available resins designed for this purpose, a gel polystyrene and a macroporous acrylic resin, was more effective than alum treatment for two of the natural waters studied, but inferior for a third. The resins were overall superior to cationic polymers. The NOM was separated into four fractions based on hydrophobic and hydrophilic properties. Alum was not as effective as ion exchange for the elimination of individual ionic NOM fractions. It was better than cationic polymers for removal of humic and fulvic acids, although polyDADMAC was as good for one water. For the removal of charged compounds alum then polyDADMAC were the best performers for that water. Unequivocal evidence was obtained that coagulants remove material that is not adsorbed by resins, and vice versa. A combination of coagulation with a cationic polymer and adsorption by an anion exchanger removed essentially all of the NOM. The preference of the coagulants was for the larger, more hydrophobic molecules, and of resins for smaller highly charged hydrophilic molecules. Each fraction had trihalomethane formation potentials in the range 11-24 microg/mg, except for one water that was more reactive. Hence, the actual amount of each fraction in the original water becomes a crucial factor. PMID:12448555

  1. 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

  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. 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. PMID:21704354

  4. 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. PMID:22926249

  5. 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.

  6. 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. PMID:26857441

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. Thrombin-Responsive Gated Silica Mesoporous Nanoparticles As Coagulation Regulators.

    PubMed

    Bhat, Ravishankar; Ribes, Àngela; Mas, Núria; Aznar, Elena; Sancenón, Félix; Marcos, M Dolores; Murguía, Jose R; Venkataraman, Abbaraju; Martínez-Máñez, Ramón

    2016-02-01

    The possibility of achieving sophisticated actions in complex biological environments using gated nanoparticles is an exciting prospect with much potential. We herein describe new gated mesoporous silica nanoparticles (MSN) loaded with an anticoagulant drug and capped with a peptide containing a thrombin-specific cleavage site. When the coagulation cascade was triggered, active thrombin degraded the capping peptidic sequence and induced the release of anticoagulant drugs to delay the clotting process. The thrombin-dependent response was assessed and a significant increase in coagulation time in plasma from 2.6 min to 5 min was found. This work broadens the application of gated silica nanoparticles and demonstrates their ability to act as controllers in a complex scenario such as hemostasis. PMID:26794474

  12. 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.

  13. Examining coagulation-complement crosstalk: complement activation and thrombosis.

    PubMed

    Foley, Jonathan H

    2016-05-01

    The coagulation and complement systems are ancestrally related enzymatic cascades of the blood. Although their primary purposes have diverged over the past few hundred million years, they remain inextricably connected. Both complement and coagulation systems limit infection by pathogens through innate immune mechanisms. Recently, it has been shown that hyperactive complement (in particular, elevated C5a/C5b-9) is involved in the pathogenesis (including thrombosis) of diseases such as paroxysmal nocturnal hemoglobinuria, atypical haemolytic uremic syndrome, antiphospholipid syndrome and bacteremia. Although these diseases together account for many thrombosis cases, there are many more where complement activation is not considered a causative factor leading to thrombosis. To better understand what role complement may play in the pathogenesis of thrombosis a better understanding of the mechanisms that cause over-active complement in thrombotic disease is required. PMID:27207425

  14. Routine coagulation testing: do we need a discard tube?

    PubMed

    Masih, Markas; Kakkar, Naveen

    2014-12-01

    When coagulation tests are performed, the recommended guideline is that a discard tube be used and the coagulation testing should be done only on the second tube. This guideline is however inconsistently enforced and most laboratories follow a single tube draw for routine coagulation testing. Few studies have however, challenged this guideline and have shown that comparable results can be obtained in both tubes when a two tube draw is used. This prospective study was done over a 3 months period in the hematology laboratory under the Clinical Hematology unit of a tertiary care teaching institution in North India. Fifty-six paired specimens were drawn from healthy volunteers following the prescribed "two tube draw" method. Prothrombin time (PT) and activated partial thromboplastin time (APTT) were performed within 1 h of sample collection on a fully automated photo-optical coagulation instrument (Ceveron-Alpha). Paired results for PT and APTT were compared using Bland-Altman plots for method comparison. There was good correlation between the PT, INR and APTT of the first and second tubes with bias of 0.09, -0.05 and 0.3 respectively). Bland-Altman plots showed acceptable agreement between the two values with 95 % confidence interval ranging from -0.62 to 0.79 for PT, -0.05 to 0.06 for INR and -3.9 to 4.6 for APTT. Our study has shown no significant difference between PT and APTT values for the first and second tubes. Hence the use of a discard tube is not required. PMID:25435740

  15. 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

  16. 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.

  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. 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. PMID:25151883

  19. Protein composition affects variation in coagulation properties of buffalo milk.

    PubMed

    Bonfatti, V; Gervaso, M; Rostellato, R; Coletta, A; Carnier, P

    2013-07-01

    The aim of this study was to investigate the effects exerted by the content of casein and whey protein fractions on variation of pH, rennet-coagulation time (RCT), curd-firming time (K20), and curd firmness of Mediterranean buffalo individual milk. Measures of milk protein composition and assessment of genotypes at CSN1S1 and CSN3 were obtained by reversed-phase HPLC analysis of 621 individual milk samples. Increased content of αS1-casein (CN) was associated with delayed coagulation onset and increased K20, whereas average pH, RCT, and K20 decreased when β-CN content increased. Milk with low κ-CN content exhibited low pH and RCT relative to milk with high content of κ-CN. Increased content of glycosylated κ-CN was associated with unfavorable effects on RCT. Effects of milk protein composition on curd firmness were less important than those on pH, RCT, and K20. Likely, this occurred as a consequence of the very short RCT of buffalo milk, which guaranteed a complete strengthening of the curd even in the restricted 31 min time of analysis of coagulation properties and for samples initially showing soft curds. Effects of CSN1S1-CSN3 genotypes on coagulation properties were not to be entirely ascribed to existing variation in milk protein composition associated with polymorphisms at CSN1S1 and CSN3 genes. Although the role of detailed milk protein composition in variation of cheese yield needs to be further investigated, findings of this study suggest that modification of the relative content of specific CN fractions can relevantly influence the behavior of buffalo milk during processing. PMID:23684020

  20. Interaction between Cryptosporidium oocysts and water treatment coagulants.

    PubMed

    Bustamante, H A; Shanker, S R; Pashley, R M; Karaman, M E

    2001-09-01

    The electrokinetic properties of gamma-irradiated Cryptosporidium oocysts in the presence of coagulants (ferric chloride and alum) and coagulant aids (DADMAC based cationic polyelectrolytes) have been studied. The zeta potential of the oocysts was unaffected by the addition of ferric chloride at all pH values (3-10) studied. Addition of alum resulted in reversal of the oocysts charge, which suggests that the initial stage in the coagulation process leading to floc formation proceeds via the adsorption of hydrolysed aluminium species. The cationic polyelectrolyte Magnafloc LT35 was adsorbed onto iron flocs at doses of 0.1 mg/L even against an electrostatic barrier. The cationic polyelectrolyte only adsorbed and caused charge reversal at the oocyst surface at around 0.4 mg/L, suggesting a lower affinity for this surface. These results indicate that the oocysts, unlike inorganic colloidal materials such as metal oxides, appear to possess a lower surface density of active or charged sites. The lower density of sites, combined with the rapid precipitation of iron salts, may be responsible for the lack of specific adsorption of either hydroxylated ferric species or primary iron hydroxide particles on the oocysts. Further, this suggests that a process of sweep flocculation, where oocysts are engulfed in flocs during coagulation and floc formation, is the more likely mechanism involved. By comparison, it is likely that the specific interaction of hydrolysed aluminium species with the oocysts surface would result in a stronger link at the oocyst-floc interface and that the flocculation process may initially proceed via charge neutralisation. PMID:11487115

  1. Blood viscosity during coagulation at different shear rates

    PubMed Central

    Ranucci, Marco; Laddomada, Tommaso; Ranucci, Matteo; Baryshnikova, Ekaterina

    2014-01-01

    Abstract During the coagulation process, blood changes from a liquid to a solid gel phase. These changes are reflected by changes in blood viscosity; however, blood viscosity at different shear rates (SR) has not been previously explored during the coagulation process. In this study, we investigated the viscosity changes of whole blood in 10 subjects with a normal coagulation profile, using a cone‐on‐plate viscosimeter. For each subject, three consecutive measurements were performed, at a SR of 20, 40, 80 sec−1. On the basis of the time‐dependent changes in blood viscosity, we identified the gel point (GP), the time‐to‐gel point (TGP), the maximum clot viscosity (MCV), and the clot lysis half‐time (CLH). The TGP significantly (P = 0.0023) shortened for increasing SR, and was significantly associated with the activated partial thromboplastin time at a SR of 20 sec−1 (P = 0.038) and 80 sec−1 (P = 0.019). The MCV was significantly lower at a SR of 80 sec−1 versus 40 sec−1 (P = 0.027) and the CLH significantly (P = 0.048) increased for increasing SR. These results demonstrate that measurement of blood viscosity during the coagulation process offers a number of potentially useful parameters. In particular, the association between the TGP and the activated partial thromboplastin time is an expression of the clotting time (intrinsic and common pathway), and its shortening for increasing SR may be interpreted the well‐known activating effects of SR on platelet activation and thrombin generation. Further studies focused on the TGP under conditions of hypo‐ or hypercoagulability are required to confirm its role in the clinical practice. PMID:24994896

  2. Commonly Used Dietary Supplements on Coagulation Function during Surgery

    PubMed Central

    Wang, Chong-Zhi; Moss, Jonathan; Yuan, Chun-Su

    2015-01-01

    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 of 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 4 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 difficult to

  3. 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.

  4. Human plasma kallikrein releases neutrophil elastase during blood coagulation.

    PubMed Central

    Wachtfogel, Y T; Kucich, U; James, H L; Scott, C F; Schapira, M; Zimmerman, M; Cohen, A B; Colman, R W

    1983-01-01

    Elastase is released from human neutrophils during the early events of blood coagulation. Human plasma kallikrein has been shown to stimulate neutrophil chemotaxis, aggregation, and oxygen consumption. Therefore, the ability of kallikrein to release neutrophil elastase was investigated. Neutrophils were isolated by dextran sedimentation, and elastase release was measured by both an enzyme-linked immunosorbent assay, and an enzymatic assay using t-butoxy-carbonyl-Ala-Ala-Pro-Val-amino methyl coumarin as the substrate. Kallikrein, 0.1-1.0 U/ml, (0.045-0.45 microM), was incubated with neutrophils that were preincubated with cytochalasin B (5 micrograms/ml). The release of elastase was found to be proportional to the kallikrein concentration. Kallikrein released a maximum of 34% of the total elastase content, as measured by solubilizing the neutrophils in the nonionic detergent Triton X-100. A series of experiments was carried out to determine if kallikrein was a major enzyme involved in neutrophil elastase release during blood coagulation. When 10 million neutrophils were incubated in 1 ml of normal plasma in the presence of 30 mM CaCl2 for 90 min, 2.75 micrograms of elastase was released. In contrast, neutrophils incubated in prekallikrein-deficient or Factor XII-deficient plasma released less than half of the elastase, as compared with normal plasma. The addition of purified prekallikrein to prekallikrein-deficient plasma restored neutrophil elastase release to normal levels. Moreover, release of elastase was enhanced in plasma deficient in C1-inhibitor, the major plasma inhibitor of kallikrein. This release was not dependent upon further steps in the coagulation pathway, or on C5a, since levels of elastase, released in Factor XI- or C5-deficient plasma, were similar to that in normal plasma, and an antibody to C5 failed to inhibit elastase release. These data suggest that kallikrein may be a major enzyme responsible for the release of elastase during blood

  5. 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.

  6. [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. PMID:2362035

  7. Simulation of reflected light intensity changes during navigation and radio-frequency lesioning in the brain

    NASA Astrophysics Data System (ADS)

    Johansson, Johannes D.; Fredriksson, Ingemar; Wa˚Rdell, Karin; Eriksson, Ola

    2009-07-01

    An electrode with adjacent optical fibers for measurements during navigation and radio frequency lesioning in the brain is modeled for Monte Carlo simulations of light transport in brain tissue. Relative reflected light intensity at 780 nm, I780, from this electrode and probes with identical fiber configuration are simulated using the intensity from native white matter as reference. Models are made of homogeneous native and coagulated gray, thalamus, and white matter as well as blood. Dual layer models, including models with a layer of cerebrospinal fluid between the fibers and the brain tissue, are also made. Simulated I780 was 0.16 for gray matter, 0.67 for coagulate gray matter, 0.36 for thalamus, 0.39 for coagulated thalamus, unity for white matter, 0.70 for coagulated white matter, and 0.24 for blood. Thalamic matter is also found to reflect more light than gray matter and less than white matter in clinical studies. In conclusion, the reflected light intensity can be used to differentiate between gray and white matter during navigation. Furthermore, coagulation of light gray tissue, such as the thalamus, might be difficult to detect using I780, but coagulation in darker gray tissue should result in a rapid increase of I780.

  8. Role of adipose tissue in haemostasis, coagulation and fibrinolysis.

    PubMed

    Faber, D R; de Groot, Ph G; Visseren, F L J

    2009-09-01

    Obesity is associated with an increased incidence of insulin resistance (IR), type 2 diabetes mellitus and cardiovascular diseases. The increased risk for cardiovascular diseases could partly be caused by a prothrombotic state that exists because of abdominal obesity. Adipose tissue induces thrombocyte activation by the production of adipose tissue-derived hormones, often called adipokines, of which some such as leptin and adiponectin have been shown to directly interfere with platelet function. Increased adipose tissue mass induces IR and systemic low-grade inflammation, also affecting platelet function. It has been demonstrated that adipose tissue directly impairs fibrinolysis by the production of plasminogen activator inhibitor-1 and possibly thrombin-activatable fibrinolysis inhibitor. Adipose tissue may contribute to enhanced coagulation by direct tissue factor production, but hypercoagulability is likely to be primarily caused by affecting hepatic synthesis of the coagulation factors fibrinogen, factor VII, factor VIII and tissue factor, by releasing free fatty acids and pro-inflammatory cytokines (tumour necrosis factor-alpha, interleukin-1beta and interleukin-6) into the portal circulation and by inducing hepatic IR. Adipose tissue dysfunction could thus play a causal role in the prothrombotic state observed in obesity, by directly and indirectly affecting haemostasis, coagulation and fibrinolysis. PMID:19460118

  9. 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).

  10. 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