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Sample records for prothrombin complex concentrates

  1. Superwarfarin ingestion treated successfully with prothrombin complex concentrate.

    PubMed

    Haesloop, Olivia; Tillick, Allison; Nichol, Graham; Strote, Jared

    2016-01-01

    Superwarfarin, a common component of rat poison, can cause long-lasting, severe coagulopathy and life-threatening hemorrhage when ingested. We report a case of intentional rat poison consumption with subsequent hemorrhage and hypotension requiring rapid coagulopathy reversal and resuscitation in the emergency department. In addition to traditional blood products, prothrombin complex concentrate was administered. Although prothrombin complex concentrate is increasingly used for severe hemorrhage in anticoagulated patients, it may be particularly useful in superwarfarin ingestions given the extreme, persistent coagulapathies that can occur. PMID:26070236

  2. Clinical review: Prothrombin complex concentrates - evaluation of safety and thrombogenicity

    PubMed Central

    2011-01-01

    Prothrombin complex concentrates (PCCs) are used mainly for emergency reversal of vitamin K antagonist therapy. Historically, the major drawback with PCCs has been the risk of thrombotic complications. The aims of the present review are to examine thrombotic complications reported with PCCs, and to compare the safety of PCCs with human fresh frozen plasma. The risk of thrombotic complications may be increased by underlying disease, high or frequent PCC dosing, and poorly balanced PCC constituents. The causes of PCC thrombogenicity remain uncertain but accumulating evidence indicates the importance of factor II (prothrombin). With the inclusion of coagulation inhibitors and other manufacturing improvements, today's PCCs may be considered safer than earlier products. PCCs may be considered preferable to fresh frozen plasma for emergency anticoagulant reversal, and this is reflected in the latest British and American guidelines. Care should be taken to avoid excessive substitution with prothrombin, however, and accurate monitoring of patients' coagulation status may allow thrombotic risk to be reduced. The risk of a thrombotic complication due to treatment with PCCs should be weighed against the need for rapid and effective correction of coagulopathy. PMID:21345266

  3. Prothrombin complex concentrates utility for warfarin-associated hemorrhage

    PubMed Central

    Soyuncu, Secgin; Aslan, Savas; Mutlu, Halil; Bektas, Firat

    2015-01-01

    Introduction: Prothrombin Complex Concentrate (PCC) for reversal of warfarin is the main therapeutic option in cases of life-threatening bleeding. Aim of the study was to investigate for using 4-factor PCC brought to the therapeutic levels of International Normalized Ratio (INR) values in cases of life-threatening bleeding in Emergency Department. Methods: This retrospective cohort study was performed in a tertiary care university emergency department. Patients with active bleeding who were taking warfarin with INR levels of ≥1.5, and had received 4-factor prothrombin complex concentrate for treatment were included in to study. Results: A total of 75 patients were included in the study. The median age of the study participants was 68 (minimum 23 to maximum 87) years and 45.3% (n = 34) of them were male. INR levels was normalized all patients who were received 4-factor PCC. Red blood cell (RBC) was transfused in 16 patients (21%) because of the low hemoglobin levels. Mean unite of the RBC packet was 2,75. The lengths of hospital stay of receiving 4-factor PCC rate were determined 4.9 ± 8.7 days. No thrombotic complications or adverse drug reactions were observed after 4-factor PCC administration in any of the patients. Conclusions: In our study 4-factor PCC was found to be effective and safe in rapidly reversing the effects of warfarin. PMID:25932234

  4. Prothrombin Complex Concentrates for Bleeding in the Perioperative Setting.

    PubMed

    Ghadimi, Kamrouz; Levy, Jerrold H; Welsby, Ian J

    2016-05-01

    Prothrombin complex concentrates (PCCs) contain vitamin K-dependent clotting factors (II, VII, IX, and X) and are marketed as 3 or 4 factor-PCC formulations depending on the concentrations of factor VII. PCCs rapidly restore deficient coagulation factor concentrations to achieve hemostasis, but like with all procoagulants, the effect is balanced against thromboembolic risk. The latter is dependent on both the dose of PCCs and the individual patient prothrombotic predisposition. PCCs are approved by the US Food and Drug Administration for the reversal of vitamin K antagonists in the setting of coagulopathy or bleeding and, therefore, can be administered when urgent surgery is required in patients taking warfarin. However, there is growing experience with the off-label use of PCCs to treat patients with surgical coagulopathic bleeding. Despite their increasing use, there are limited prospective data related to the safety, efficacy, and dosing of PCCs for this indication. PCC administration in the perioperative setting may be tailored to the individual patient based on the laboratory and clinical variables, including point-of-care coagulation testing, to balance hemostatic benefits while minimizing the prothrombotic risk. Importantly, in patients with perioperative bleeding, other considerations should include treating additional sources of coagulopathy such as hypofibrinogenemia, thrombocytopenia, and platelet disorders or surgical sources of bleeding. Thromboembolic risk from excessive PCC dosing may be present well into the postoperative period after hemostasis is achieved owing to the relatively long half-life of prothrombin (factor II, 60-72 hours). The integration of PCCs into comprehensive perioperative coagulation treatment algorithms for refractory bleeding is increasingly reported, but further studies are needed to better evaluate the safe and effective administration of these factor concentrates. PMID:26983050

  5. Clinical effectiveness and safety outcomes associated with prothrombin complex concentrates.

    PubMed

    Hedges, Ashley; Coons, James C; Saul, Melissa; Smith, Roy E

    2016-07-01

    Prothrombin complex concentrates (PCCs) are indicated for urgent reversal of warfarin and used for reversal of novel oral anticoagulants, in patients with acute major bleeding or need for an urgent procedure. The research goal was to evaluate effectiveness and safety outcomes with PCC usage at our institution. A retrospective review of electronic medical records identified patients that received a PCC commercially available in the United States (KCentra(®) or Profilnine(®)) at twelve hospitals in a tertiary care health system from July 1, 2013 to April 30, 2014. A total of 193 patients received PCC, of which 184 patients received four-factor PCC. The patient population was 48 % male and 75 % Caucasian, with a mean age of 73 years old. Clinical outcomes of interest included time to achieve a target INR ≤1.3, time to Hgb >7 g/dL, and incidence of thromboembolism. A total of 143 patients were on warfarin (74.1 %) at baseline, whereas 18 patients (9.3 %) were taking a novel anticoagulant. Target INR of ≤1.3 was achieved in 125 patients (65.8 %), within a median time of 8.03 h (IQR 3.38-34.07). Among patients with a baseline Hgb <7 g/L (n = 13), the median time to Hgb >7 g/dL was 8.48 h (IQR 6.95-13.00). Eight patients (4.1 %) developed an acute venous thromboembolism following PCC administration. INR reversal was achieved in approximately two-thirds of patients, with a low incidence of venous thromboembolism. Four-factor PCC is a viable alternative to plasma. PMID:26685667

  6. Prothrombin complex concentrate in the reduction of blood loss during orthotopic liver transplantation: PROTON-trial

    PubMed Central

    2013-01-01

    Background In patients with cirrhosis, the synthesis of coagulation factors can fall short, reflected by a prolonged prothrombin time. Although anticoagulants factors are decreased as well, blood loss during orthotopic liver transplantation can still be excessive. Blood loss during orthotopic liver transplantation is currently managed by transfusion of red blood cell concentrates, platelet concentrates, fresh frozen plasma, and fibrinogen concentrate. Transfusion of these products may paradoxically result in an increased bleeding tendency due to aggravated portal hypertension. The hemostatic effect of these products may therefore be overshadowed by bleeding complications due to volume overload. In contrast to these transfusion products, prothrombin complex concentrate is a low-volume highly purified concentrate, containing the four vitamin K dependent coagulation factors. Previous studies have suggested that administration of prothrombin complex concentrate is an effective method to normalize a prolonged prothrombin time in patients with liver cirrhosis. We aim to investigate whether the pre-operative administration of prothrombin complex concentrate in patients undergoing liver transplantation for end-stage liver cirrhosis, is a safe and effective method to reduce perioperative blood loss and transfusion requirements. Methods/Design This is a double blind, multicenter, placebo-controlled randomized trial. Cirrhotic patients with a prolonged INR (≥1.5) undergoing liver transplantation will be randomized between placebo or prothrombin complex concentrate administration prior to surgery. Demographic, surgical and transfusion data will be recorded. The primary outcome of this study is RBC transfusion requirements. Discussion Patients with advanced cirrhosis have reduced plasma levels of both pro- and anticoagulant coagulation proteins. Prothrombin complex concentrate is a low-volume plasma product that contains both procoagulant and anticoagulant proteins and

  7. Prothrombin complex concentrate for warfarin-induced bleeding in a patient with a mechanical aortic valve

    PubMed Central

    Kar, Rahul; Abel, Erik; Burcham, Pamela; Firstenberg, Michael S.

    2013-01-01

    Reversal of anticoagulation-induced bleeding in the perioperative period can be challenging, particularly with an unstable patient with a mechanical valve. We present a case of life-threatening bleeding successfully managed with a prothrombin complex concentrate as an alternative to fresh frozen plasma. PMID:23667067

  8. Prothrombin Complex Concentrate for Intracerebral Hemorrhage Secondary to Vitamin K Deficiency Bleeding in a 6-Week-Old Child.

    PubMed

    Rech, Megan A; Wittekindt, Lindsay; Friedman, Samantha D; Kling, Kendall; Ubogy, David

    2015-12-01

    Four-factor prothrombin complex concentrate is approved for use of life-threatening bleeding secondary to vitamin K antagonism in adults. We describe the use of four-factor prothrombin complex concentrate for hemostasis in a 6-week-old child with life-threatening vitamin K dependent-bleeding who never received vitamin K prophylaxis at birth. PMID:26454577

  9. Emergency reversal of anticoagulation with a three-factor prothrombin complex concentrate in patients with intracranial haemorrhage

    PubMed Central

    Imberti, Davide; Barillari, Giovanni; Biasioli, Chiara; Bianchi, Marina; Contino, Laura; Duce, Rita; D’Incà, Marco; Gnani, Maria Cristina; Mari, Elisa; Ageno, Walter

    2011-01-01

    Background Intracranial haemorrhage is a serious and potentially fatal complication of oral anticoagulant therapy. Prothrombin complex concentrates can substantially shorten the time needed to reverse the effects of oral anticoagulants. The aim of this study was to determine the efficacy and safety of a prothrombin complex concentrate for rapid reversal of oral anticoagulant therapy in patients with intracranial haemorrhage. Methods Patients receiving oral anticoagulant therapy and suffering from acute intracranial haemorrhage were eligible for this prospective cohort study if their International Normalised Ratio (INR) was higher than or equal to 2.0. The prothrombin complex concentrate was infused at doses of 35–50 IU/kg, stratified according to the initial INR. Results Forty-six patients (25 males; mean age: 75 years; range 38–92 years) were enrolled. The median INR at presentation was 3.5 (range, 2–9). At 30 minutes after administration of the prothrombin complex concentrate, the median INR was 1.3 (range, 0.9–3), and the INR then declined to less than or equal to 1.5 in 75% of patients. The benefit of the prothrombin complex concentrate was maintained for a long time, since the median INR remained lower than or equal to 1.5 (median, 1.16; range, 0.9–2.2) at 96% of all post-infusion time-points up to 96 hours. No thrombotic complications or significant adverse events were observed during hospitalisation; six patients (13%) died, but none of these deaths was judged to be related to administration of the prothrombin complex concentrate. Conclusions Prothrombin complex concentrates are an effective, rapid and safe treatment for the urgent reversal of oral anticoagulation in patients with intracranial haemorrhage. Broader use of prothrombin complex concentrates in this clinical setting appears to be appropriate. PMID:21251465

  10. Use of prothrombin complex concentrates and fibrinogen concentrates in the perioperative setting: a systematic review.

    PubMed

    Lin, David M; Murphy, Linda S; Tran, Minh-Ha

    2013-04-01

    The use of prothrombin complex concentrates (PCCs) and fibrinogen concentrates (FIBCs) to achieve hemostasis in the perioperative setting as alternatives to allogeneic blood products remains controversial. To examine the efficacy and safety of PCCs and FIBCs, we conducted a systematic review-in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement-to compare the use of these transfusion alternatives in bleeding surgical patients. We performed a literature search of English articles published between July 1997 and July 2012 in MEDLINE via PubMed, The Cochrane Library, and CINAHL. Five randomized trials and 15 nonrandomized studies with a comparator group were included in the final review. Studies were sorted into 1 of the following 3 clinical settings: cardiac surgery, non-cardiac surgery, and reversal of warfarin anticoagulation. Risk of bias was assessed using the Cochrane risk of bias tool. With the exception of 2 randomized controlled trials, the existing body of literature on the use of PCCs and FIBCs in the perioperative setting was assessed to have a high degree of methodological bias. Overall, prospective studies in the cardiac surgery grouping suggested that patients receiving FIBC and/or PCCs required less allogeneic blood transfusion and had less chest tube drainage. In studies of warfarin reversal, PCCs more rapidly corrected the International Normalized Ratio compared to plasma; however, in the setting of intracranial hemorrhage, functional outcomes were poor regardless of the reversal strategy. With regards to safety outcomes, reporting was not uniform and raises concerns of underreporting. Adequately powered, methodologically sound trials would be required for more definitive conclusions to be drawn about the efficacy of PCCs and FIBC over conventional blood components for the treatment of perioperative coagulopathy in bleeding patients. PMID:23462530

  11. Reversibility of Apixaban Anticoagulation with a Four-Factor Prothrombin Complex Concentrate in Healthy Volunteers.

    PubMed

    Nagalla, S; Thomson, L; Oppong, Y; Bachman, B; Chervoneva, I; Kraft, W K

    2016-06-01

    It was hypothesized that the four-factor prothrombin complex concentrate (4F-PCC) Kcentra 25 unit/kg would reverse impairment of thrombin generation in healthy volunteers dosed with apixaban to steady state. In this randomized, two-period crossover, assessor-blinded trial, 12 healthy subjects received 5 mg apixaban every 12 h. Three h after the fifth dose, four-factor prothrombin complex concentrate (4F-PCC) 25 unit/kg or saline were infused. Serial blood samples were assessed for thrombin generation using PPP-reagent and PPP-reagent low, anti-Xa, PT, and PTT assays. Geometric mean ratio was calculated at 30 min postinfusion, and at 24, 48, and 72 h. Peak thrombin generation was 76% higher at 30 min postinfusion with 4F-PCC (p = 0.025). The difference declined to 24% at 24 h and resolved by 48 h. Other thrombin generation parameters were also partially normalized. There was no difference between 4F-PCC and saline in anti-Xa assessment at 30 min or later time points. PMID:27170068

  12. In vivo reversal of the anticoagulant effect of rivaroxaban with four-factor prothrombin complex concentrate.

    PubMed

    Barco, Stefano; Whitney Cheung, Y; Coppens, Michiel; Hutten, Barbara A; Meijers, Joost C M; Middeldorp, Saskia

    2016-01-01

    Four-factor prothrombin complex concentrate (PCC) 50 iu/kg is able to swiftly restore haemostatic parameters in healthy subjects on rivaroxaban. We hypothesized that lower dosages of PCC may be sufficient to restore normal haemostasis. In this double-blind, crossover, placebo-controlled study, we compared the effects of PCC 37.5 iu/kg, PCC 25 iu/kg, and placebo on thrombin generation (endogenous thrombin potential, ETP) and prothrombin time in six healthy subjects receiving twice-daily rivaroxaban 15 mg for 2.5 days. Fifteen min after infusion of PCC 37.5 iu/kg, ETP increased from 47 ± 16% to 64 ± 22% (P = 0.03; pre-rivaroxaban ETP: 92 ± 14%) and remained higher than after placebo over 24 h (P = 0.001). PCC 25 iu/kg did not modify ETP within 15 min (53 ± 11% to 59 ± 12%; P = 0.14) and was not different from placebo over 24 h (P = 0.31). ETP reached pre-rivaroxaban levels within 6 h after PCC 37.5 iu/kg infusion and within 12-24 h after PCC 25 iu/kg infusion. Both dosages restored rivaroxaban-induced prothrombin time prolongation after 15 min (P < 0.001). Placebo did not have an effect on coagulation parameters. 37.5 iu/kg of PCC leads to partial restoration of thrombin generation, whereas 25 iu/kg does not. PCC 37.5 iu/kg may be insufficient for immediate full reversal of peak therapeutic rivaroxaban levels. PMID:26488126

  13. Favorable outcome of rivaroxaban-associated intracerebral hemorrhage reversed by 4-factor prothrombin complex concentrate: impact on thrombin generation.

    PubMed

    Kauffmann, Sophie; Chabanne, Russell; Coste, Aurélien; Longeras, François; Sinegre, Thomas; Schmidt, Jeannot; Samama, Charles-Marc; Constantin, Jean-Michel; Lebreton, Aurélien

    2015-06-01

    The management of life-threatening bleeding associated with rivaroxaban remains a challenge for physicians due to the lack of evidence about clinically effective options for anticoagulation reversal. We report a favorable outcome in a patient receiving rivaroxaban prophylaxis, who developed a spontaneous subdural hematoma treated by a surgical evacuation and administration of 4-factor prothrombin complex concentrate. Classical coagulation variables were associated with impaired thrombin generation. Reversal with prothrombin complex concentrates improved all thrombin generation measures. Thrombin generation tests may be suitable for assessing the clinical utility of reversal drugs on rivaroxaban-induced coagulopathy. PMID:26035221

  14. Reversal of oral factor Xa inhibitors by prothrombin complex concentrates: a re-appraisal.

    PubMed

    Dzik, W H

    2015-06-01

    Oral factor Xa inhibitors are an attractive class of anticoagulants expected to have broad application. Rapid and reliable reversal of the anticoagulant effect is important for patients with bleeding complications or those in need of urgent reversal for procedures. While no specific reversal agent is yet available, multiple published clinical guidelines suggest that four-factor prothrombin complex concentrates (PCC) should be considered when urgent reversal is desired. This presentation updates prior reviews on this topic (Crit Care, 17, 2013, 230; Thromb Haemost, 111, 2014, 189; J Thromb Thrombolysis, 2015, 39, 395); and summarizes more recent evidence in human studies indicating that four-factor PCCs available in North America do not reverse oral factor Xa-inhibitor anticoagulants. New agents on the horizon appear to be far more promising as therapies for reversal or oral factor Xa inhibitors. PMID:26149022

  15. Clinical Applications of 4-Factor Prothrombin Complex Concentrate: A Practical Pathologist's Perspective.

    PubMed

    Unold, David; Tormey, Christopher A

    2015-12-01

    A 4-factor prothrombin complex concentrate (4F-PCC), containing therapeutic doses of vitamin K-dependent coagulation factors, was recently licensed in the United States for reversal of vitamin K antagonist therapy. However, given the emergence of several oral anticoagulants for which there are no specific reversal agents, and the existence of many other complex bleeding disorders, it is likely that clinicians will seek to use 4F-PCCs for any number of off-label indications. Thus, the goal of this review is to explore practical issues regarding 4F-PCC, with an emphasis on issues relevant to blood bankers and pathologists. Specifically, our aims are to (1) examine the role of 4F-PCC in vitamin K antagonist reversal, (2) review its potential use in the treatment of hemorrhage due to novel oral anticoagulants, and (3) explore potential uses in liver disease, trauma-associated bleeding, and rare coagulopathies. Safety and other practical considerations of 4F-PCCs will also be discussed. PMID:26619030

  16. Efficacy of prothrombin complex concentrates for the emergency reversal of dabigatran-induced anticoagulation.

    PubMed

    Grottke, Oliver; Aisenberg, James; Bernstein, Richard; Goldstein, Patrick; Huisman, Menno V; Jamieson, Dara G; Levy, Jerrold H; Pollack, Charles V; Spyropoulos, Alex C; Steiner, Thorsten; Del Zoppo, Gregory J; Eikelboom, John

    2016-01-01

    Dabigatran is effective in decreasing the risk of ischaemic stroke in patients with atrial fibrillation. However, like all anticoagulants, it is associated with a risk of bleeding. In cases of trauma or emergency surgery, emergency reversal of dabigatran-induced anticoagulation may be required. A specific reversal agent for dabigatran, idarucizumab, has been approved by the US Food and Drug Administration. Alternative reversal agents are available, such as prothrombin complex concentrates (PCCs) and activated PCCs (aPCCs). In this review we evaluate the role of PCCs and aPCCs in the reversal of dabigatran anticoagulation and consider which tests are appropriate for monitoring coagulation in this setting. Pre-clinical studies, small clinical studies and case reports indicate that PCCs and aPCCs may be able to reverse dabigatran-induced anticoagulation in a dose-dependent manner. However, dosing based on coagulation parameters can be difficult because available assays may not provide adequate sensitivity and specificity for measuring anticoagulation induced by dabigatran or the countering effects of PCCs/aPCCs. In addition, PCCs or aPCCs can potentially provoke thromboembolic complications. Despite these limitations and the fact that PCCs and aPCCs are not yet licensed for dabigatran reversal, their use appears to be warranted in patients with life-threatening haemorrhage if idarucizumab is not available. PMID:27125504

  17. Prothrombin complex concentrate use in coagulopathy of lethal brain injuries increases organ donation.

    PubMed

    Joseph, Bellal; Aziz, Hassan; Pandit, Viraj; Hays, Daniel; Kulvatunyou, Narong; Tang, Andrew; Wynne, Julie; O' Keeffe, Terence; Green, Donald J; Friese, Randall S; Gruessner, Rainer; Rhee, Peter

    2014-04-01

    Coagulopathy is a defined barrier for organ donation in patients with lethal traumatic brain injuries. The purpose of this study was to document our experience with the use of prothrombin complex concentrate (PCC) to facilitate organ donation in patients with lethal traumatic brain injuries. We performed a 4-year retrospective analysis of all patients with devastating gunshot wounds to the brain. The data were analyzed for demographics, change in international normalized ratio (INR), and subsequent organ donation. The primary end point was organ donation. Eighty-eight patients with lethal traumatic brain injury were identified from the trauma registry of whom 13 were coagulopathic at the time of admission (mean INR 2.2 ± 0.8). Of these 13 patients, 10 patients received PCC in an effort to reverse their coagulopathy. Mean INR before PCC administration was 2.01 ± 0.7 and 1.1 ± 0.7 after administration (P < 0.006). Correction of coagulopathy was attained in 70 per cent (seven of 10) patients. Of these seven patients, consent for donation was obtained in six patients and resulted in 19 solid organs being procured. The cost of PCC per patient was $1022 ± 544. PCC effectively reveres coagulopathy associated with lethal traumatic brain injury and enabled patients to proceed to organ donation. Although various methodologies exist for the treatment of coagulopathy to facilitate organ donation, PCC provides a rapid and cost-effective therapy for reversal of coagulopathy in patients with lethal traumatic brain injuries. PMID:24887662

  18. Less Is More: Low-dose Prothrombin Complex Concentrate Effective in Acute Care Surgery Patients.

    PubMed

    Quick, Jacob A; Meyer, Jennifer M; Coughenour, Jeffrey P; Barnes, Stephen L

    2015-06-01

    Optimal dosing of prothrombin complex concentrate (PCC) has yet to be defined and varies widely due to concerns of efficacy and thrombosis. We hypothesized a dose of 15 IU/kg actual body weight of a three-factor PCC would effectively correct coagulopathy in acute care surgery patients. Retrospective review of 41 acute care surgery patients who received 15 IU/kg (± 10%) actual body weight PCC for correction of coagulopathy. Demographics, laboratory results, PCC dose, blood and plasma transfusions, and thrombotic complications were analyzed. We performed subset analyses of trauma patients and those taking warfarin. Mean age was 69 years (18-94 years). Thirty (73%) trauma patients, 8 (20%) emergency surgery patients, 2 (5%) burns, and 1 (2%) nontrauma neurosurgical patient were included. Mean PCC dose was 1305.4 IU (14.2 IU/kg actual body weight). Mean change in INR was 2.52 to 1.42 (p 0.00004). Successful correction (INR <1.5) was seen in 78 per cent. Treatment failures had a higher initial INR (4.3 vs 2.03, p 0.01). Mean plasma transfusion was 1.46 units. Mean blood transfusion was 1.61 units. Patients taking prehospital warfarin (n = 29, 71%) had higher initial INR (2.78 vs 1.92, p 0.05) and received more units of plasma (1.93 vs 0.33, p 0.01) than those not taking warfarin. No statistical differences were seen between trauma and nontrauma patients. One thrombotic event occurred. Administration of low-dose PCC, 15 IU/kg actual body weight, effectively corrects coagulopathy in acute care surgery patients regardless of warfarin use, diagnosis or plasma transfusion. PMID:26031281

  19. Case studies in prehospital care from London HEMS: pre-hospital administration of prothrombin complex concentrate to the head-injured patient.

    PubMed

    Lendrum, Robbie A; Kotze, Jean-Pierre; Lockey, David J; Weaver, Anne E

    2013-03-01

    A case of pre-hospital administration of prothrombin complex concentrate to a patient anticoagulated with warfarin and with suspected intracranial haemorrhage is described. Effective, early reversal of anticoagulation by the time of arrival at hospital was achieved. PMID:23349352

  20. Pharmacokinetics, thrombogenicity and safety of a double viral inactivated factor IX concentrate compared with a prothrombin complex concentrate.

    PubMed

    Ruiz-Sáez, A; Hong, A; Arguello, A; Echenagucia, M; Boadas, A; Fabbrizzi, F; Minichilli, F; Bosch, N B

    2005-11-01

    Therapeutic options for developing countries have to assure an optimum safety and efficacy and low-cost antihaemophilic concentrates. A single blind randomized crossover study was carried out in 12 previously treated HB patients, comparing the pharmacokinetics (PK), thrombogenicity (TG) and safety of two plasma-derived double-inactivated (solvent/detergent heating at 100 degrees C, 30 min) factor IX (FIX) concentrates, UMAN COMPLEX DI (product A) [plasma-derived prothrombin concentrates (PCC)] and a high purity FIX concentrate AIMAFIX DI (product B, HPFIX). In a non-bleeding state, they received one single intravenous dose 50 IU FIX kg(-1) of PCC or HPFIX, and after a wash-out period of 14 days, the other product. We evaluated acute tolerance and determined PK parameters based on FIX levels measured over a 50 h postinfusion period. We studied fibrinogen, platelets, antithrombin, F1 + 2, TAT, D-dimer, over a 360 min postinfusion period. Ten cases remained in on-demand treatment for 6 months, five with PCC and five with HPFIX. PK and anti-FIX inhibitors were repeated at 3 and 6 months. No inhibitors were detected. PK values (PCC vs. HPFIX): clearence (CL; mL h(-1) kg(-1)) 5.2 +/- 1.4 vs. 6.5 +/- 1.4; the volume of distribution at steady state (mL kg(-1)) 154.9 +/- 54.9 vs. 197.5 +/- 72.5; mean residence time (h) 29.7 +/- 8.1 vs. 30.7 +/- 9.2; T(1/2) (h) 22.3 +/- 7 vs. 23.5 +/- 12.3; incremental recovery (IR; U dL(-1) U(-1) kg(-1)) 0.96 +/- 0.17 vs. 0.76 +/- 0.13. HPFIX showed significant lower IR and higher CL. There were no differences in PK at 3 and 6 months. In TG, significant increments in TAT and F1 + 2 at 30 min and 6 h were found with PCC. Product B PK results agrees with reported results for other HPFIX preparations. Use of PCC product A has to consider its thrombogenic activity. PMID:16236107

  1. Efficacy of Prothrombin Complex Concentrate Treatment in Patients with Liver Coagulopathy Who Underwent Various Invasive Hepatobiliary and Gastrointestinal Procedures

    PubMed Central

    Lesmana, Cosmas Rinaldi A.; Cahyadinata, Lidwina; Pakasi, Levina S.; Lesmana, Laurentius A.

    2016-01-01

    Background Prothrombin complex concentrates (PCCs) containing prothrombin, factors VII, IX, and X, as well as the inhibitors protein C and S have been used as an emergent reversal for oral anticoagulation therapy. The use of PCCs in hepatobiliary disorder patients or patients with liver coagulopathy who need to undergo invasive procedures has not been well studied. Objective To evaluate the efficacy of PCC treatment in order to control or prevent bleeding complications in patients with liver coagulopathy who undergo various invasive procedures. Methods This was a prospective, open-label, non-randomized, before-and-after study in patients with hepatobiliary disorders who underwent invasive procedures accompanied by liver impairment and received PCC injection (Cofact®, Sanquin, The Netherlands). Patients with coagulopathy from various causes were recruited consecutively. Data collected were the episodes of bleeding, liver function test and the international normalized ratio (INR) before and after PCC therapy. The primary endpoint was INR change after treatment, while secondary endpoints included bleeding control and bleeding event after treatment. Results Thirty patients (17 men, 13 women) were enrolled. Patients’ mean age was 57.0 + 15.5 years. Liver cirrhosis was found in 14 patients (46.7%). The procedures consisted of liver biopsy, liver abscess aspiration, abdominal paracentesis, therapeutic upper gastrointestinal endoscopy, abdominal surgery, endoscopic retrograde cholangiopancreatography and percutaneous transhepatic biliary drainage. After treatment, 25 patients (83.3%) showed a decreased median INR (from 1.6 to 1.3) (p < 0.001, Wilcoxon's signed-rank test). Five patients failed to show INR reduction. No new bleeding event related to the invasive procedures was observed. Conclusion PCC treatment is effective to control and prevent bleeding complications in patients with liver coagulopathy who undergo invasive procedures. PMID:27482190

  2. Efficacy of viral clearance methods used in the manufacture of activated prothrombin complex concentrates: focus on AUTOPLEX T.

    PubMed

    Horwith, G; Revie, D R

    1999-09-01

    Various methods are described for the elimination of infectious viruses from activated prothrombin complex concentrates (aPCCs) and for the analysis of the final products (AUTOPLEX T and FEIBA VH). Viruses of concern in human plasma-derived products are enveloped (hepatitis B and C, cytomegalovirus, Epstein-Barr virus, and human immunodeficiency virus [HIV]) and nonenveloped (hepatitis A and parvovirus B19). Donated blood used for AUTOPLEX T is screened for antihepatitis C, HBsAg, anti-HIV types 1 and 2, and p24 antigen. Plasma pools utilized for raw materials are also tested by PCR for HIV and hepatitis C virus. Partial virus inactivation and partitioning are achieved by purification of the aPCC. Further reduction of virus infectivity is accomplished by lyophilization and dry-heat treatment. Each step undergoes virus elimination validation studies in which a relevant sample is 'spiked' with the appropriate virus or model virus. The total reduction in virus from raw material to final product can then be calculated. For AUTOPLEX T the cumulative log10 reduction factors for several viruses vary from 4.2 to 14.3. This ensures an exceptionally high margin of safety. Definitive evidence for product safety was obtained by clinical observation of treated patients. The viral inactivation process of AUTOPLEX T involves a four-tier viral safety program, including Cohn alcohol fractionation and dry-heat treatment, in place of the two-stage vapour-heating process for FEIBA. PMID:10597384

  3. Successful Use of Four Factor-Prothrombin Complex Concentrate for Congenital Factor X Deficiency in the Setting of Neurosurgery.

    PubMed

    Siddon, Alexa J; Tormey, Christopher A

    2016-08-01

    Congenital factor X deficiency is an extremely rare coagulation disorder that can place patients at risk for spontaneous hemorrhage or excessive bleeding in the setting of trauma or invasive procedures. Given the rarity of this disorder, there is little published guidance on how best to prevent or treat bleeding. Herein, we report a case of a 56-year-old white man with congenital factor X deficiency who was scheduled for major neurosurgery and who was treated perioperatively with 4-factor prothrombin complex concentrate (4F-PCC). Doses of 4F-PCC at 15 U per kg, administered immediately preoperatively and once at 24 hours postoperatively, allowed for successful completion of an anterior cervical discectomy and fusion without excessive bleeding. Moreover, no thromboembolic complications were observed. As such, given the wide availability of 4F-PCC, it may be considered as a first-line therapy and an alternative to fresh frozen plasma for factor X deficiencies, particularly in high-risk operative cases. PMID:27378481

  4. Retrospective evaluation of the clinical use of prothrombin complex concentrate for the reversal of anticoagulation with vitamin K antagonists.

    PubMed

    Cruz, Jennifer L; Moss, Mary C; Chen, Sheh-Li; Hansen, Kayla M; Amerine, Lindsey B

    2015-06-01

    Anticoagulation reversal is a time-sensitive intervention for the prevention of life-threatening hemorrhagic events occurring with bleeding or surgery. Recommendations for the most effective and well tolerated reversal agent in these settings remain controversial. Several clinical guidelines for the management of intracerebral hemorrhage support use of prothrombin complex concentrates (PCCs) for the rapid reversal of warfarin-associated coagulopathy despite limited clinical data. The purpose of this investigation was to evaluate the efficacy and safety of PCC for the rapid reversal of anticoagulation by vitamin K antagonists for life-threatening bleeding or emergent surgery and to assess adherence to a hospital-based protocol. A retrospective chart review was conducted of adult patients receiving PCC for the reversal of anticoagulation. Patients were assessed according to indication for anticoagulation reversal. The primary outcome measure was adequacy of international normalized ratio reversal. Other outcomes included cessation of bleeding, thrombotic complications, and adherence to an institutional-based guideline for the use of PCC. ICU and hospital length of stay and 30-day mortality was assessed. There were 70 patients included in this study. Mean international normalized ratio was reduced from 3.1 to 1.6 following administration of at least one dose of PCC. Cessation of bleeding occurred in 65.7% of patients. Clinical assessment was unclear in 18.6%. Thrombotic complications were observed in 7.1% of patients. The 30-day mortality rate was found to be 14.3%. These data demonstrate that PCC is a well tolerated and effective method for anticoagulation reversal associated with a relatively high 30-day survival rate. PMID:25688457

  5. Reversal of warfarin associated coagulopathy with 4-factor prothrombin complex concentrate in traumatic brain injury and intracranial hemorrhage.

    PubMed

    Yanamadala, Vijay; Walcott, Brian P; Fecci, Peter E; Rozman, Peter; Kumar, Jay I; Nahed, Brian V; Swearingen, Brooke

    2014-11-01

    Warfarin-associated intracranial hemorrhage is associated with a high mortality rate. Ongoing coagulopathy increases the likelihood of hematoma expansion and can result in catastrophic hemorrhage if surgery is performed without reversal. The current standard of care for emergency reversal of warfarin is with fresh frozen plasma (FFP). In April 2013, the USA Food and Drug Administration approved a new reversal agent, 4-factor prothrombin complex concentrate (PCC), which has the potential to more rapidly correct coagulopathy. We sought to determine the feasibility and outcomes of using PCC for neurosurgical patients. A prospective, observational study of all patients undergoing coagulopathy reversal for intracranial hemorrhage from April 2013 to December 2013 at a single, tertiary care center was undertaken. Thirty three patients underwent emergent reversal of coagulopathy using either FFP or PCC at the discretion of the treating physician. Intracranial hemorrhage included subdural hematoma, intraparenchymal hematoma, and subarachnoid hemorrhage. FFP was used in 28 patients and PCC was used in five patients. International normalized ratio at presentation was similar between groups (FFP 2.9, PCC 3.1, p=0.89). The time to reversal was significantly shorter in the PCC group (FFP 256 minutes, PCC 65 minutes, p<0.05). When operations were performed, the time delay to perform operations was also significantly shorter in the PCC group (FFP 307 minutes, PCC 159 minutes, p<0.05). In this preliminary experience, PCC appears to provide a rapid reversal of coagulopathy. Normalization of coagulation parameters may prevent further intracranial hematoma expansion and facilitate rapid surgical evacuation, thereby improving neurological outcomes. PMID:24953825

  6. Comparison of 3-Factor Prothrombin Complex Concentrate and Low-Dose Recombinant Factor VIIa for Warfarin Reversal

    PubMed Central

    2014-01-01

    Introduction Prothrombin complex concentrate (PCC) and recombinant Factor VIIa (rFVIIa) have been used for emergent reversal of warfarin anticoagulation. Few clinical studies have compared these agents in warfarin reversal. We compared warfarin reversal in patients who received either 3 factor PCC (PCC3) or low-dose rFVIIa (LDrFVIIa) for reversal of warfarin anticoagulation. Methods Data were collected from medical charts of patients who received at least one dose of PCC3 (20 units/kg) or LDrFVIIa (1000 or 1200 mcg) for emergent warfarin reversal from August 2007 to October 2011. The primary end-points were achievement of an INR 1.5 or less for efficacy and thromboembolic events for safety. Results Seventy-four PCC3 and 32 LDrFVIIa patients were analyzed. Baseline demographics, reason for warfarin reversal, and initial INR were equivalent. There was no difference in the use of vitamin K or fresh frozen plasma. More LDrFVIIa patients achieved an INR of 1.5 or less (71.9% vs. 33.8%, p =0.001). The follow-up INR was lower after LDrFVIIa (1.25 vs. 1.75, p < 0.05) and the percent change in INR was larger after LDrFVIIa (54.1% vs. 38.8%, p = 0.002). There was no difference in the number of thromboembolic events (2 LDrFVIIa vs. 5 PCC3, p = 1.00), mortality, length of hospital stay, or cost. Conclusions Based on achieving a goal INR of 1.5 or less, LDrFVIIa was more likely than PCC3 to reverse warfarin anticoagulation. Thromboembolic events were equivalent in patients receiving PCC3 and LDrFVIIa. PMID:24731393

  7. Prothrombin Complex Concentrate

    PubMed Central

    Cada, Dennis J.; Levien, Terri L.; Baker, Danial E.

    2013-01-01

    Each month, subscribers to The Formulary Monograph Service receive 5 to 6 well-documented monographs on drugs that are newly released or are in late phase 3 trials. The monographs are targeted to Pharmacy & Therapeutics Committees. Subscribers also receive monthly 1-page summary monographs on agents that are useful for agendas and pharmacy/nursing in-services. A comprehensive target drug utilization evaluation/medication use evaluation (DUE/MUE) is also provided each month. With a subscription, the monographs are sent in print and are also available on-line. Monographs can be customized to meet the needs of a facility. A drug class review is now published monthly with The Formulary Monograph Service. Through the cooperation of The Formulary, Hospital Pharmacy publishes selected reviews in this column. For more information about The Formulary Monograph Service, call The Formulary at 800-322-4349. The December 2013 monograph topics are vortioxetine, mechlorethamine gel, brimonidine tartrate topical gel, obinutuzumab, and miltefosine. The DUE/MUE is on vortioxetine. PMID:24474837

  8. A French multicenter randomised trial comparing two dose-regimens of prothrombin complex concentrates in urgent anticoagulation reversal

    PubMed Central

    2013-01-01

    Introduction Prothrombin complex concentrates (PCC) are haemostatic blood preparations indicated for urgent anticoagulation reversal, though the optimal dose for effective reversal is still under debate. The latest generation of PCCs include four coagulation factors, the so-called 4-factor PCC. The aim of this study was to compare the efficacy and safety of two doses, 25 and 40 IU/kg, of 4-factor PCC in vitamin K antagonist (VKA) associated intracranial haemorrhage. Methods We performed a phase III, prospective, randomised, open-label study including patients with objectively diagnosed VKA-associated intracranial haemorrhage between November 2008 and April 2011 in 22 centres in France. Patients were randomised to receive 25 or 40 IU/kg of 4-factor PCC. The primary endpoint was the international normalised ratio (INR) 10 minutes after the end of 4-factor PCC infusion. Secondary endpoints were changes in coagulation factors, global clinical outcomes and incidence of adverse events (AEs). Results A total of 59 patients were randomised: 29 in the 25 IU/kg and 30 in the 40 IU/kg group. Baseline demographics and clinical characteristics were comparable between the groups. The mean INR was significantly reduced to 1.2 - and ≤1.5 in all patients of both groups - 10 minutes after 4-factor PCC infusion. The INR in the 40 IU/kg group was significantly lower than in the 25 IU/kg group 10 minutes (P = 0.001), 1 hour (P = 0.001) and 3 hours (P = 0.02) after infusion. The 40 IU/kg dose was also effective in replacing coagulation factors such as PT (P = 0.038), FII (P = 0.001), FX (P <0.001), protein C (P = 0.002) and protein S (0.043), 10 minutes after infusion. However, no differences were found in haematoma volume or global clinical outcomes between the groups. Incidence of death and thrombotic events was similar between the groups. Conclusions Rapid infusion of both doses of 4-factor PCC achieved an INR of 1.5 or less in all patients with a lower INR observed in the 40 IU

  9. 4-Factor Prothrombin Complex Concentrate (PCC4, Kcentra®) Protocol Reduces Blood Requirements for Heart Transplantation: A Novel Protocol.

    PubMed

    Pratt Cleary, Jacqueline; Hodge, Laura; Palmer, Brittany; Barreiro, Christopher J; Ingemi, Amanda

    2016-01-01

    BACKGROUND All patients with a ventricular assist device (VAD) awaiting heart transplantation are anticoagulated with warfarin to prevent thromboembolism. The use of 4 factor prothrombin complex concentrate (PCC4, Kcentra®) for anticoagulation reversal prior to surgery may include benefits such as quicker reversal, longer duration of action, and a reduction in total volume of blood products used compared to other reversal practices. The study objective is to evaluate benefits of using an anticoagulation reversal protocol featuring PCC4, over standard of care in heart transplant patients requiring anticoagulation. MATERIAL AND METHODS This is a single center, combined retrospective and prospective, time-matched cohort study compared 12 patients transplanted pre-protocol and 11 patients transplanted post-protocol. The primary outcome was the total volume of blood and blood products used. Secondary outcomes included length of hospital and ICU stay, safety and adverse events, primary chest closure, and a cost comparison. RESULTS The PCC4 reversal protocol showed a significant reduction in total blood volume received with an overall decrease of 1.76L (4.20L pre-protocol, 2.45L post-protocol, P=0.037), total units of blood products infused (20 units pre, 12 units post, P=0.033), and units of packed red blood cells (7 units pre, 3 units post, P=0.033). All heart transplant recipients were listed Status 1A with the primary indication being infection (n=12; 52%). Baseline characteristics, survival, and cost were not different between the two groups. There were no thrombotic events or patient that experienced serious reactions to PCC4. Secondary outcomes were only significant to time to INR reversal. CONCLUSIONS Patients treated with the PCC4 protocol demonstrated a significant decrease in volume of blood and units of blood products required prior to chest closure for heart transplant patients. PCC4 was found to be a safe and beneficial agent in anticoagulation reversal for

  10. 3-Factor Versus 4-Factor Prothrombin Complex Concentrate for Warfarin Reversal in Severe Bleeding: A Multicenter, Retrospective, Propensity-Matched Pilot Study.

    PubMed

    Jones, G Morgan; Erdman, Michael J; Smetana, Keaton S; Mohrien, Kerry M; Vandigo, Joseph E; Elijovich, Lucas

    2016-07-01

    Current guidelines recommend 4-factor prothrombin complex concentrate (4PCC) for emergent reversal of bleeding secondary to warfarin. While current research has demonstrated superiority of 4PCC over plasma, direct comparisons with 3-factor PCC (3PCC) are lacking. The purpose of this study is to compare the efficacy and safety of 3PCC and 4PCC. We conducted a retrospective analysis of patients who received PCC at one of four medical centers. All patients in the 3PCC group were treated at one center that utilizes a fixed, weight-based dosing protocol. After evaluation of all patients meeting inclusion criteria, propensity-score matching was used to adjust for differences in treatment characteristics. There was no difference in the primary outcome of INR ≤ 1.4 between 3PCC and 4PCC in both the unmatched (85.7 vs. 90.6 %; p = 0.37) and matched (84.2 vs. 92.1 %; p = 0.48) analyses. There was a significant difference in goal INR achieved favoring 4PCC (56.3 vs 90.0 %; p < 0.02) when baseline INR > 4.0. A total of three thrombotic events were documented, all in the 4PCC group. We found no difference in the rate of INR reversal in those treated with 3PCC and 4PCC. However, those with a baseline INR > 4.0 may experience more successful INR reversal with 4PCC. PMID:26721625

  11. Increased risk of volume overload with plasma compared with four‐factor prothrombin complex concentrate for urgent vitamin K antagonist reversal

    PubMed Central

    Refaai, Majed A.; Goldstein, Joshua N.; Lee, Martin L.; Durn, Billie L.; Milling, Truman J.; Sarode, Ravi

    2015-01-01

    BACKGROUND Plasma is commonly used for vitamin K antagonist (VKA) reversal, but observational studies suggest that it is associated with transfusion‐related adverse reactions (e.g., volume overload). However, this issue has not previously been addressed in a randomized controlled trial (RCT). STUDY DESIGN AND METHODS Factors associated with volume overload were examined using data from two Phase IIIb RCTs comparing plasma with four‐factor prothrombin complex concentrate (4F‐PCC, Beriplex/Kcentra, CSL Behring) for urgent VKA reversal. VKA‐treated patients with major bleeding (NCT00708435) or requiring an urgent surgical or invasive procedure (NCT00803101) were randomly assigned (1:1) to receive either plasma or 4F‐PCC, concomitant with vitamin K. Adverse events (AEs) and serious AEs were prospectively captured up to Day 10 and 45, respectively. Volume overload predictors were evaluated on a univariate and multivariate basis. RESULTS A total of 388 patients (4F‐PCC, n = 191; plasma, n = 197) were enrolled. Volume overload occurred in 34 (9%) patients (4F‐PCC, n = 9; plasma, n = 25). In univariate analyses, use of plasma (vs. 4F‐PCC), use of nonstudy plasma and/or platelets, race, history of congestive heart failure (CHF), and history of renal disease were associated with volume overload. In multivariate analyses, use of plasma (vs. 4F‐PCC), history of CHF, and history of renal disease were independent volume overload predictors. In an additional analysis restricted to volume overload events recorded up to Day 7, only use of plasma (vs. 4F‐PCC) was an independent volume overload predictor. CONCLUSIONS After adjusting for other potential risk factors, plasma use was independently associated with a greater risk of volume overload than 4F‐PCC in patients requiring urgent VKA reversal. PMID:26135740

  12. Reversal of Vitamin K Antagonist (VKA) effect in patients with severe bleeding: a French multicenter observational study (Optiplex) assessing the use of Prothrombin Complex Concentrate (PCC) in current clinical practice

    PubMed Central

    2012-01-01

    Introduction Prothrombin Complex Concentrate (PCC) is a key treatment in the management of bleeding related to Vitamin K antagonists (VKA). This study aimed to evaluate prospectively PCC use in patients with VKA-related bleeding in view of the French guidelines published in 2008. Methods All consecutive patients with VKA-related bleeding treated with a 4-factor PCC (Octaplex®) were selected in 33 French hospitals. Collected data included demographics, site and severity of bleeding, modalities of PCC administration, International Normalized Ratio (INR) values before and after PCC administration, outcomes and survival rate 15 days after infusion. Results Of 825 patients who received PCC between August 2008 and December 2010, 646 had severe bleeding. The main haemorrhage sites were intracranial (43.7%) and abdominal (24.3%). Mean INR before PCC was 4.4 ± 1.9; INR was unavailable in 12.5% of patients. The proportions of patients who received a PCC dose according to guidelines were 15.8% in patients with initial INR 2-2.5, 41.5% in patients with INR 2.5-3, 40.8% in patients with INR 3-3.5, 26.9% in patients with INR > 3.5, and 63.5% of patients with unknown INR. Vitamin K was administered in 84.7% of patients. The infused dose of PCC did not vary with initial INR; the mean dose was 25.3 ± 9.8 IU/Kg. Rates of controlled bleeding and target INR achievement were similar, regardless of whether or not patients were receiving PCC doses as per the guidelines. No differences in INR after PCC treatment were observed, regardless of whether or not vitamin K was administered. INR was first monitored after a mean time frame of 4.5 ± 5.6 hours post PCC. The overall survival rate at 15 days after PCC infusion was 75.4% (65.1% in patients with intracranial haemorrhage). A better prognosis was observed in patients reaching the target INR. Conclusions Severe bleeding related to VKA needs to be better managed, particularly regarding the PCC infused dose, INR monitoring and

  13. Evaluation of expanded bed adsorption chromatography for extraction of prothrombin complex from Cohn Supernatant I.

    PubMed

    McCann, Karl B; Gomme, Peter T; Wu, John; Bertolini, Joseph

    2008-07-01

    This study evaluated the feasibility of substituting expanded bed adsorption (EBA) chromatography for an existing chromatographic purification process for the isolation of prothrombin complex concentrate (PCC) from Cohn Supernatant I. The EBA chromatography (Streamline) resins were compared to the current DEAE-cellulose resin for the extraction of PCC from Cohn SNI. EBA chromatography resins efficiently bound PCC from Cohn SNI at a significantly higher flow rate of up to 300 cm/h compared to 30 cm/h for the current DEAE-cellulose process. Composition and yield of the recovered PCC reflected the elution conditions used. The results indicate that EBA chromatography could be used to efficiently produce PCC comparable to existing products. PMID:18329287

  14. Membrane-dependent Interaction of Factor Xa and Prothrombin with Factor Va in the Prothrombinase Complex

    PubMed Central

    Qureshi, Shabir H.; Yang, Likui; Manithody, Chandrashekhara; Rezaie, Alireza R.

    2009-01-01

    Because all three protein components of prothrombinase, factors (f) Xa and Va and prothrombin, bind to negatively charged membrane phospholipids, the exact role of the membrane in the prothrombinase reaction has not been fully understood. In this study, we prepared deletion derivatives of fXa and prothrombin in which both the Gla and first EGF-like domains of the protease (E2-fXa) as well as the Gla and both kringle domains of the substrate (prethrombin-2) were deleted. The fVa-mediated catalytic activity of E2-fXa toward prethrombin-2 was analyzed in both the absence and presence of phospholipids composed of 80% phosphatidylcholine (PC) and 20% phosphatidylserine (PS). PCPS markedly accelerated the initial rate of prethrombin-2 activation by E2-fXa, with the cofactor exhibiting saturation only in the presence of phospholipids (apparent Kd ∼60 nM). Competitive kinetic studies in the presence of the two exosite-1-specific ligands Tyr63-sulfated hirudin54-65 and TM456 suggested that while both peptides are highly effective inhibitors of the fVa-mediated activation of prethrombin-2 by E2-fXa in the absence of PCPS, they are ineffective competitors in the presence of phospholipids. Since neither E2-fXa nor prethrombin-2 can interact with membranes, these results suggest that fVa interaction with PCPS improves the affinity of the activation complex for the proexosite-1 of the substrate. Direct binding studies employing OG488-EGR-labeled fXa and E2-fXa revealed that the interaction of the Gla-domain of fXa with PCPS also induces conformational changes in the protease to facilitate its high-affinity interaction with fVa. PMID:19378973

  15. Antibodies to Phosphatidylserine/Prothrombin Complex in Antiphospholipid Syndrome: Analytical and Clinical Perspectives.

    PubMed

    Peterson, Lisa K; Willis, Rohan; Harris, E Nigel; Branch, Ware D; Tebo, Anne E

    2016-01-01

    Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by thrombosis and/or pregnancy-related morbidity accompanied by persistently positive antiphospholipid antibodies (aPL). Current laboratory criteria for APS classification recommend testing for lupus anticoagulant as well as IgG and IgM anticardiolipin, and beta-2 glycoprotein I (anti-β2GPI) antibodies. However, there appears to be a subset of patients with classical APS manifestations who test negative for the recommended criteria aPL tests. While acknowledging that such patients may have clinical features that are not of an autoimmune etiology, experts also speculate that these "seronegative" patients may test negative for relevant autoantibodies as a result of a lack of harmonization and/or standardization. Alternatively, they may have aPL that target other antigens involved in the pathogenesis of APS. In the latter, autoantibodies that recognize a phosphatidylserine/prothrombin (PS/PT) complex have been reported to be associated with APS and may have diagnostic relevance. This review highlights analytical and clinical attributes associated with PS/PT antibodies, taking into consideration the performance characteristics of criteria aPL tests in APS with specific recommendations for harmonization and standardization efforts. PMID:26975968

  16. Determining the effect of storage conditions on prothrombin time, activated partial thromboplastin time and fibrinogen concentration in rat plasma samples.

    PubMed

    Goyal, Vinod Kumar; Kakade, Somesh; Pandey, Santosh Kumar; Gothi, Anil Kalidas; Nirogi, Ramakrishna

    2015-10-01

    Coagulation parameters are usually included in clinical and preclinical safety studies to evaluate the effect of xenobiotics on the extrinsic or intrinsic pathways of coagulation. The analysis is generally performed at the time of terminal sacrifice where many activities are scheduled. Chances of delay in analysis are likely particularly when blood is collected for coagulation via the abdominal vena cava. This experiment was planned to assess the variations in coagulation parameters caused by delay in analysis as well as by storage conditions. Blood was collected from the posterior vena cava under isoflurane anesthesia, and the plasma was separated immediately. Coagulation parameters were evaluated at 0, 6, 24 and 48 h from the plasma stored at room temperature, as well as plasma stored under refrigerated and freezing conditions. Stability of the analytes in blood was also evaluated under refrigerated conditions for 6 h. All parameters were analyzed using a semi-automated coagulometer. Prothrombin time (PT) was stable under all three storage conditions for up to 6 h. Although statistically significant differences were observed for activated partial thromboplastin time (APTT) at room and refrigeration temperatures for up to 6 h, the difference was clinically non-relevant. Fibrinogen was found to be the most stable parameter that showed consistency in results even up to 48 h under all three storage conditions. Plasma for PT can be stored and analyzed without any significant changes for up to 6 h from the actual blood collection, while fibrinogen level testing can be extended for up to 48 h after collection under any storage condition. For reliable APTT results, plasma samples should be run immediately after collection. PMID:26206586

  17. Prothrombin time (PT)

    MedlinePlus

    PT; Pro-time; Anticoagulant-prothrombin time; Clotting time: protime; INR; International normalized ratio ... PT is measured in seconds. Most of the time, results are given as what is called INR ( ...

  18. Genetics Home Reference: prothrombin deficiency

    MedlinePlus

    ... Patients and Caregivers: How Blood Clots Orphanet: Congenital factor II deficiency University of Iowa Health Care: Prothrombin Gene Mutation Patient Support and Advocacy Resources (2 links) Canadian Hemophilia Society National Hemophilia Foundation: Factor II ... Genetic Testing Registry (1 link) Prothrombin ...

  19. Recombinant snake venom prothrombin activators.

    PubMed

    Lövgren, Ann

    2013-01-01

    Three prothrombin activators; ecarin, which was originally isolated from the venom of the saw-scaled viper Echis carinatus, trocarin from the rough-scaled snake Tropidechis carinatus, and oscutarin from the Taipan snake Oxyuranus scutellatus, were expressed in mammalian cells with the purpose to obtain recombinant prothrombin activators that could be used to convert prothrombin to thrombin. We have previously reported that recombinant ecarin can efficiently generate thrombin without the need for additional cofactors, but does not discriminate non-carboxylated prothrombin from biologically active γ-carboxylated prothrombin. Here we report that recombinant trocarin and oscutarin could not efficiently generate thrombin without additional protein co-factors. We confirm that both trocarin and oscutarin are similar to human coagulation Factor X (FX), explaining the need for additional cofactors. Sequencing of a genomic fragment containing 7 out of the 8 exons coding for oscutarin further confirmed the similarity to human FX. PMID:23111318

  20. Genetics Home Reference: prothrombin thrombophilia

    MedlinePlus

    ... produced from the F2 gene, prothrombin (also called coagulation factor II), is the precursor to a protein ... on PubMed (1 link) PubMed OMIM (2 links) COAGULATION FACTOR II THROMBOPHILIA DUE TO THROMBIN DEFECT Sources ...

  1. A dimeric form of prothrombin on membrane surfaces.

    PubMed Central

    Anderson, P J

    1998-01-01

    Blood coagulation requires the conversion of zymogens to active enzymes. These reactions are facilitated by Ca2+-dependent protein binding to membrane surfaces containing anionic phospholipids. Here it is shown that only in the presence of both Ca2+ and phospholipid vesicles composed of phosphatidylcholine and phosphatidylserine can a prothrombin dimer be chemically cross-linked. A cross-linker containing evenly spaced reactive groups was prepared by activating the carboxy groups of a ten-residue glutamic acid peptide and allowed to react with physiological concentrations of prothrombin. When Ca2+ and anionic phospholipids were both present during exposure to the cross-linker, it was found that more than 50% of the prothrombin was trapped as a chemically defined dimer with reaction times of the order of 1 min. The dimer yield remained high even when reactions were performed at high phospholipid-to-protein ratios at protein concentrations an order of magnitude less than physiological. Amino acid sequencing of a CNBr peptide produced from the purified dimer localized the cross-link to residues Lys341 and Lys427 of prothrombin. The specificity and high yield under mild conditions of the cross-linking suggest that dimeric membrane bound prothrombin might be a physiologically relevant substrate for the formation of thrombin. Prothrombinase converts this modified protein to an enzyme that catalyses the hydrolysis of a thrombin chromogenic substrate as efficiently as thrombin and is inhibited by a thrombin active-site directed inhibitor, but is a thrombin dimer. The thrombin dimer has impaired activity compared with thrombin with respect to physiological functions requiring binding to exosite I. A model based on the known structure of thrombin is presented that can account for the prothrombin dimer and the properties of the dimeric thrombin formed from it. PMID:9841875

  2. 21 CFR 866.5735 - Prothrombin immunological test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... antibodies) prothrombin aid in the diagnosis of blood-clotting disorders. (b) Classification. Class I... that consists of the reagents used to measure by immunochemical techniques the prothrombin...

  3. 21 CFR 866.5735 - Prothrombin immunological test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... antibodies) prothrombin aid in the diagnosis of blood-clotting disorders. (b) Classification. Class I... that consists of the reagents used to measure by immunochemical techniques the prothrombin...

  4. 21 CFR 866.5735 - Prothrombin immunological test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... antibodies) prothrombin aid in the diagnosis of blood-clotting disorders. (b) Classification. Class I... that consists of the reagents used to measure by immunochemical techniques the prothrombin...

  5. Structural Architecture of Prothrombin in Solution Revealed by Single Molecule Spectroscopy.

    PubMed

    Pozzi, Nicola; Bystranowska, Dominika; Zuo, Xiaobing; Di Cera, Enrico

    2016-08-26

    The coagulation factor prothrombin has a complex spatial organization of its modular assembly that comprises the N-terminal Gla domain, kringle-1, kringle-2, and the C-terminal protease domain connected by three intervening linkers. Here we use single molecule Förster resonance energy transfer to access the conformational landscape of prothrombin in solution and uncover structural features of functional significance that extend recent x-ray crystallographic analysis. Prothrombin exists in equilibrium between two alternative conformations, open and closed. The closed conformation predominates (70%) and features an unanticipated intramolecular collapse of Tyr(93) in kringle-1 onto Trp(547) in the protease domain that obliterates access to the active site and protects the zymogen from autoproteolytic conversion to thrombin. The open conformation (30%) is more susceptible to chymotrypsin digestion and autoactivation, and features a shape consistent with recent x-ray crystal structures. Small angle x-ray scattering measurements of prothrombin wild type stabilized 70% in the closed conformation and of the mutant Y93A stabilized 80% in the open conformation directly document two envelopes that differ 50 Å in length. These findings reveal important new details on the conformational plasticity of prothrombin in solution and the drastic structural difference between its alternative conformations. Prothrombin uses the intramolecular collapse of kringle-1 onto the active site in the closed form to prevent autoactivation. The open-closed equilibrium also defines a new structural framework for the mechanism of activation of prothrombin by prothrombinase. PMID:27435675

  6. Simultaneous Characterization of Lateral Lipid and Prothrombin Diffusion Coefficients by Z-Scan Fluorescence Correlation Spectroscopy

    PubMed Central

    Štefl, Martin; Kułakowska, Anna; Hof, Martin

    2009-01-01

    Abstract A new (to our knowledge) robust approach for the determination of lateral diffusion coefficients of weakly bound proteins is applied for the phosphatidylserine specific membrane interaction of bovine prothrombin. It is shown that z-scan fluorescence correlation spectroscopy in combination with pulsed interleaved dual excitation allows simultaneous monitoring of the lateral diffusion of labeled protein and phospholipids. Moreover, from the dependencies of the particle numbers on the axial sample positions at different protein concentrations phosphatidylserine-dependent equilibrium dissociation constants are derived confirming literature values. Increasing the amount of membrane-bound prothrombin retards the lateral protein and lipid diffusion, indicating coupling of both processes. The lateral diffusion coefficients of labeled lipids are considerably larger than the simultaneously determined lateral diffusion coefficients of prothrombin, which contradicts findings reported for the isolated N-terminus of prothrombin. PMID:19651025

  7. Complex concentrate pretreatment FY 1986 progress report

    SciTech Connect

    lokken, R O; Scheele, R D; Strachan, D M; Toste, A P

    1986-09-01

    After of the transuranic elements are removed from complex concentrate waste by the TRUEX process, the remaining waste will be grouted for final storage. The purpose of this project, conducted at the Pacific Northwest Laboratory (PNL), is to support a future decision to grout the complexant waste without destroying the organic contents. In work performed this year, it has been demonstrated that grouts with acceptable parameters for the Transportable Grout Facility can be made using actual waste. The acceptability of these grouts from a regulatory view seems to be less of a problem than was thought at this time last year. None of the organics found in the waste are included on the US Environmental Protection Agency's Hazardous Chemicals List. 7 refs., 12 figs., 4 tabs.

  8. 21 CFR 864.7750 - Prothrombin time test.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Prothrombin time test. 864.7750 Section 864.7750...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7750 Prothrombin time test. (a) Identification. A prothrombin time test is a device used as a general screening procedure...

  9. 21 CFR 864.7750 - Prothrombin time test.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Prothrombin time test. 864.7750 Section 864.7750 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7750 Prothrombin time test. (a) Identification. A prothrombin...

  10. 21 CFR 864.7750 - Prothrombin time test.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Prothrombin time test. 864.7750 Section 864.7750...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7750 Prothrombin time test. (a) Identification. A prothrombin time test is a device used as a general screening procedure...

  11. 21 CFR 864.7750 - Prothrombin time test.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prothrombin time test. 864.7750 Section 864.7750...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7750 Prothrombin time test. (a) Identification. A prothrombin time test is a device used as a general screening procedure...

  12. 21 CFR 864.7750 - Prothrombin time test.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Prothrombin time test. 864.7750 Section 864.7750...) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7750 Prothrombin time test. (a) Identification. A prothrombin time test is a device used as a general screening procedure...

  13. Exploratory study of complexant concentrate waste processing

    SciTech Connect

    Lumetta, G.J.; Bray, L.A.; Kurath, D.E.; Morrey, J.R.; Swanson, J.L.; Wester, D.W.

    1993-02-01

    The purpose of this exploratory study, conducted by Pacific Northwest Laboratory for Westinghouse Hanford Company, was to determine the effect of applying advanced chemical separations technologies to the processing and disposal of high-level wastes (HLW) stored in underground tanks. The major goals of this study were to determine (1) if the wastes can be partitioned into a small volume of HLW plus a large volume of low-level waste (LLW), and (2) if the activity in the LLW can be lowered enough to meet NRC Class LLW criteria. This report presents the results obtained in a brief scouting study of various processes for separating radionuclides from Hanford complexant concentrate (CC) waste.

  14. Differentiation of metal ion-induced transitions of prothrombin fragment 1.

    PubMed

    Prendergast, F G; Mann, K G

    1977-02-10

    The intrinsic fluorescence of human and bovine prothrombin fragment 1 is quenched (approximately -35%) when calcium ions are bound. The intrinsic fluorescence of prothrombin is also quenched by the binding of Ca2+ but to a lesser extent (total change is approximately -6%). The prothrombin fragment 1 fluorescence transition is also effected by the binding of Mg2+, Mn2+, Gd3+, and Tb3+. With all ions the fluorescence quenching is readily reversed by titration with EDTA. Titration with any of the above ions results in a sigmoidal titration curve. The fluorescence transition midpoints (expressed as Tm) occur at the following concentrations of ions: Ca2+, 0.22 (0.35) mM; Mg2+, 0.22 (0.45) mM; Mn2+, 12.6 (12.6) muM; and Gd3+, 3.6 (5.3) muM (the values in parentheses indicate the concentration of the respective ions bound to bovine prothrombin fragment 1). The presence of phospholipid steepens the Ca2+ titration curve, significantly more so for the bovine system than for the human. Tm values for Ca2+ binding in the presence of phospholipid are 0.21 mM and 0.22 mM for binding to human and bovine prothrombin fragment 1, respectively. Sedimentation equilibrium and velocity studies indicate that prothrombin fragment 1 which is monomeric in the presence of EDTA undergoes concentration-dependent association in the presence of Ca2+. A plot of fraction monomer versus Ca2+ concentration is sigmoidal, with a Tm of approximately 1 mM Ca2+. Mg2+ is only marginally effective in promoting the dimerization, and Mn2+ and Gd3+ are even less effective. However, sedimentation studies performed in the presence of 1 mM Mg2+ at varying Ca2+ concentrations shifted the apparent dimerization transition markedly to the left, the midpoint of the transition occurring at 0.25 mM. Kinetic studies reveal that while Mg2+ by itself does not promote prothrombin activation to thrombin, Mg2+ will partially substitute for Ca2+ in prothrombin activation. In the presence of 1 mM Mg2+ maximal activation rates

  15. Structural transitions during prothrombin activation: On the importance of fragment 2

    PubMed Central

    Adams, Ty E.; Huntington, James A.

    2016-01-01

    Prothrombin is activated to thrombin by the prothrombinase complex through sequential cleavage at two distinct sites. This occurs at sites of vascular injury in a highly regulated cascade of serine protease and cofactor activation, where activated platelets provide a suitable surface for protease/cofactor/substrate assembly. The precise structural and conformational changes undergone during the transition from prothrombin to thrombin have been studied for decades, and several structures of prothrombin fragments along the activation pathway have been solved. Here we present a new structure analyzed in context of other recent structures and biochemical studies. What emerges is an unexpected mechanism that involves a change in the mode of binding of the F2 domain (fragment 2) on the catalytic domain after cleavage at Arg320, and a subsequent reorientation of the linker between the F2 and catalytic domain to present the Arg271 site for cleavage. PMID:26365066

  16. Comparison of prothrombin time tests used in the monitoring of edoxaban and their evaluation as indicators of the reversal effect.

    PubMed

    Iba, Toshiaki; Emmi, Mari; Hiki, Makoto; Nagayama, Masataka; Aihara, Koichiro; Tabe, Yoko; Yuri, Maiko; Ohsaka, Akimichi

    2016-06-01

    Clinical demand for the prompt assessment of the activity of direct-acting factor Xa inhibitors in the emergency care setting is increasing. In the present study, we examined whether prothrombin time (PT) tests can serve as a clinically useful indicator of anti-factor Xa activity. In the first series, the in vitro effect of edoxaban on PT was evaluated by spiking human plasma with edoxaban and measuring PT using three different commercial PT tests. In the second series, the reversal effect of prothrombin complex concentrates (PCC) and activated PCC (aPCC) in edoxaban-spiked plasma was evaluated. In the third series, PT of plasma samples from patients administered either 15 or 30 mg/day of edoxaban was assessed, and the results were compared with edoxaban concentrations determined by a calibrated anti-factor Xa activity assay. The spike test revealed that all PT reagents positively correlated with edoxaban. The sensitivity to edoxaban varied among the three reagents and Triniclot(®) Excel S showed the best performance. Prolonged PT by edoxaban was reversed by PCC and aPCC in a dose-dependent manner; however, complete reversal was not achieved. Positive correlation between anti-factor Xa activity and PT was shown in the clinical samples at the edoxaban range from 0 to >300 ng/mL. PMID:26984594

  17. Exploiting the antithrombotic effect of the (pro)thrombin inhibitor bothrojaracin.

    PubMed

    Assafim, Mariane; Frattani, Flávia S; Ferreira, Marcos S; Silva, Dione M; Monteiro, Robson Q; Zingali, Russolina B

    2016-09-01

    Bothrojaracin is a 27 kDa C-type lectin-like protein from Bothrops jararaca snake venom. It behaves as a potent thrombin inhibitor upon high-affinity binding to thrombin exosites. Bothrojaracin also forms a stable complex with prothrombin that can be detected in human plasma. Formation of the zymogen-inhibitor complex severely decreases prothrombin activation and contributes to the anticoagulant activity of bothrojaracin. In the present study, we employed two rodent models to evaluate the antithrombotic effect of bothrojaracin in vivo: stasis-induced thrombosis and thrombin-induced pulmonary thromboembolism. It was observed that bothrojaracin interacts with rat prothrombin in plasma. Ex-vivo assays showed stable complex formation even after 24 h of a single bothrojaracin dose. As a result, bothrojaracin showed significant antithrombotic activity in a rat venous thrombosis model elicited by thromboplastin combined with stasis. The antithrombotic activity of bothrojaracin (1 mg/kg) persisted for up to 24 h and it was associated with moderate bleeding as assessed by a tail transection method. Formation of bothrojaracin-prothrombin complex has been also observed following intravenous administration of the inhibitor into mice. As a result, bothrojaracin effectively protected mice from thrombin-induced fatal thromboembolism. We conclude that bothrojaracin is a potent antithrombotic agent in vivo and may serve as a prototype for the development of new zymogen-directed drugs that could result in prolonged half-life and possible decreased hemorrhagic risk. PMID:27179421

  18. Global Post-Authorization Safety Surveillance Study: real-world data on prophylaxis and on-demand treatment using FEIBA (an activated prothrombin complex concentrate)

    PubMed Central

    Negrier, Claude; Voisin, Sophie; Baghaei, Fariba; Numerof, Robert; Novack, Aaron; Doralt, Jennifer E.; Romanov, Vadim; Gringeri, Alessandro

    2016-01-01

    This prospective, Post-Authorization Safety Surveillance (PASS) study was carried out in patients with hemophilia A or B and inhibitors treated with FEIBA for 1 year to collect real-world data on safety and effectiveness of FEIBA. The study followed a cohort design and did not make stipulations on treatment or observation schedule, as it was designed to observe routine medical practices based on physicians’ treatment decisions, including whether patients received on-demand or prophylaxis with FEIBA. The attending physician maintained documentation, including medical records, laboratory reports, adverse event reports, and so on and a subject diary was used. Eighty-one patients were treated with FEIBA at 40 sites in 10 countries over a 4-year period. Sixty-nine patients (85.2%) had hemophilia A, two had (2.5%) hemophilia B, and ten (12.3%) had acquired hemophilia A. At baseline 45 patients (55.6%) were prescribed prophylaxis and 36 (44.6%) on-demand treatment. This study was novel in following safety and effectiveness in ‘real world’ on-demand and prophylactic use of FEIBA, and was able to collect data in these rare patients under routine clinical practice. PMID:26829366

  19. 21 CFR 866.5735 - Prothrombin immunological test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Prothrombin immunological test system. 866.5735 Section 866.5735 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems § 866.5735 Prothrombin immunological test system....

  20. 21 CFR 866.5735 - Prothrombin immunological test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Prothrombin immunological test system. 866.5735 Section 866.5735 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Immunological Test Systems § 866.5735 Prothrombin immunological test system....

  1. Elucidation of procoagulant mechanism and pathophysiological significance of a new prothrombin activating metalloprotease purified from Daboia russelii russelii venom.

    PubMed

    Thakur, Rupamoni; Chattopadhyay, Pronobesh; Ghosh, Siddharth S; Mukherjee, Ashis K

    2015-06-15

    The procoagulant proteases present in Russell's Viper venom (RVV) are responsible for promoting consumption coagulopathy in victims. In this study, a procoagulant metalloprotease (Rusviprotease) possessing prothrombin activating and α-fibrinogenase properties has been purified and characterized from RVV. Rusviprotease is a 26.8 kDa glycoprotein which also exists in other multimeric forms. The peptide mass fingerprinting and secondary structure analyses of Rusviprotease revealed its similarity with snake venom prothrombin activators and metalloproteases. Similar to group A prothrombin activators, Rusviprotease cleaved prothrombin independent of any co-factor requirement generating meizothrombin which is further cleaved to form thrombin. The Km and Vmax values of Rusviprotease towards prothrombin were determined to be 1.73 μM, and 153.5 nM thrombin generated/min/μmoles of Rusviprotease, respectively. The Km and Vmax values of Rusviprotease towards fibrinogen were calculated to be 3.14 μM and 78.7 nmol/min, respectively. Spectrofluorometric study provided the evidence of interaction between Rusviprotease and factor Xa with a Kd value of 6.64 nM. This interaction augmented the prothrombin activating property of the factor Xa-prothrombinase-Rusviprotease complex by 2.5 fold. Intravenous injection of Rusviprotease to BALB/c mice (0.1 mg/kg) resulted in in vivo defibrinogenation rendering the blood incoagulable. In conclusion, Rusviprotease is the first example of a prothrombin activator with fibrinogenolytic property purified from Daboia russelii russelii venom. PMID:25817001

  2. Prothrombin kringle-2 domain has a growth inhibitory activity against basic fibroblast growth factor-stimulated capillary endothelial cells.

    PubMed

    Lee, T H; Rhim, T; Kim, S S

    1998-10-30

    Recently, O'Reilly et al. (O'Reilly, M. S., Holmgren, L., Shing, Y., Chen, C., Rosenthal, R. A., Moses, M., Lane, W. S., Cao, Y., Sage, E. H., and Folkman, J. (1994) Cell 79, 315-328; O'Reilly, M. S., Boehm, T., Shing, Y., Fukai, N., Vasios, G., Lane, W. S., Flynn, E., Birkhead, J. R., Olsen, B. R., and Folkman, J. (1997) Cell 88, 277-285) developed a simple in vitro angiogenesis assay system using bovine capillary endothelial cell proliferation and purified potent angiogenic inhibitors, including angiostatin and endostatin. Using a simple in vitro assay for angiogenesis, we purified a protein molecule that showed anti-endothelial cell proliferative activity from the serum of New Zealand White rabbits, which was stimulated by lipopolysaccharide. The purified protein showed only bovine capillary endothelial cell growth inhibition and not any cytotoxicity. This molecule was identified as a prothrombin kringle-2 domain (fragment-2) using Edman degradation and the amino acid sequence deduced from the cloned cDNA. Both the prothrombin kringle-2 domain released from prothrombin by factor Xa cleavage and the angiogenic inhibitor purified from rabbit sera exhibited anti-endothelial cell proliferative activity. The recombinant rabbit prothrombin kringle-2 domain showed potent inhibitory activity with half-maximal concentrations (ED50) of 2 microg/ml media. As in angiostatin, the recombinant rabbit prothrombin kringle-2 domain also inhibited angiogenesis in the chorioallantoic membrane of chick embryos. PMID:9786880

  3. Should we test the prothrombin time in anticoagulated epistaxis patients?

    PubMed

    Soyka, Michael B; Holzmann, David

    2013-01-01

    Epistaxis is one of the most frequent emergencies in rhinology. Patients using anticoagulative medication are at increased risk for epistaxis. We evaluated the prothrombin time and the international normalized ratio (INR) in anticoagulated epistaxis patients. Patients suffering from epistaxis were prospectively included in a database and results from prothrombin testing were analyzed in the context of anticoagulation. One hundred sixteen of 591 epistaxis cases were identified to be on oral anticoagulation. The INR was found to be above therapeutic levels in 19 (16%) of these cases. We strongly recommend prothrombin time and INR testing in all epistaxis patients taking any sort of vitamin K antagonists. PMID:23772329

  4. Isolation and characterization of cotiaractivase, a novel low molecular weight prothrombin activator from the venom of Bothrops cotiara.

    PubMed

    Senis, Yotis A; Kim, Paul Y; Fuller, Gemma L J; García, Angel; Prabhakar, Sripadi; Wilkinson, Mark C; Brittan, Helen; Zitzmann, Nicole; Wait, Robin; Warrell, David A; Watson, Steve P; Kamiguti, Aura S; Theakston, R David G; Nesheim, Michael E; Laing, Gavin D

    2006-05-01

    In this study, we isolated a novel prothrombin activator from the venom of Bothrops cotiara, a Brazilian lance-headed pit viper (Cotiara, Jararaca preta, Biocotiara), which we have designated "cotiaractivase" (prefix: cotiar- from B. cotiara; suffix: -activase, from prothrombin activating activity). Cotiaractivase was purified using a phenyl-Superose hydrophobic interaction column followed by a Mono-Q anion exchange column. It is a single-chain polypeptide with a molecular weight of 22,931 Da as measured by mass spectroscopy. Cotiaractivase generated active alpha-thrombin from purified human prothrombin in a Ca2+-dependent manner as assessed by S2238 chromogenic substrate assay and SDS-PAGE. Cotiaractivase cleaved prothrombin at positions Arg271-Thr272 and Arg320-Ile321, which are also cleaved by factor Xa. However, the rate of thrombin generation by cotiaractivase was approximately 60-fold less than factor Xa alone and 17 x 10(6)-fold less than the prothrombinase complex. The enzymatic activity of cotiaractivase was inhibited by the chelating agent EDTA, whereas the serine protease inhibitor PMSF had no effect on its activity, suggesting that it is a metalloproteinase. Interestingly, S2238 inhibited cotiaractivase activity non-competitively, suggesting that this toxin contains an exosite that allows it to bind prothrombin independently of its active site. Tandem mass spectrometry and N-terminal sequencing of purified cotiaractivase identified peptides that were identical to regions of the cysteine-rich and disintegrin-like domains of known snake venom metalloproteinases. Cotiaractivase is a unique low molecular weight snake venom prothrombin activator that likely belongs to the metalloproteinase family of proteins. PMID:16647309

  5. Membrane-based, dry-reagent prothrombin time tests.

    PubMed

    Zweig, S E; Meyer, B G; Sharma, S; Min, C; Krakower, J M; Shohet, S B

    1996-01-01

    The authors describe a prototype membrane-based, dry-reagent prothrombin time assay for whole blood. This system uses an asymmetric polysulfone membrane to separate plasma from red blood cells, and works with samples as small as 10 microliters. The membrane contains calcium and thromboplastin, and permits the reactions of the complete extrinsic pathway to occur with minimal distortion from membrane surface interactions. Thrombin generation is monitored optically using a rhodamine-110-based fluorescent thrombin substrate. Fluorescence kinetics are analyzed to produce a prothrombin-time--equivalent parameter that can be converted to an international normalized ratio (INR) value. The system provides results that correlate well with conventional liquid phase prothrombin time assays (R2 = 0.96). PMID:8739001

  6. Complex surface concentration gradients by stenciled "electro click chemistry".

    PubMed

    Hansen, Thomas S; Lind, Johan U; Daugaard, Anders E; Hvilsted, Søren; Andresen, Thomas L; Larsen, Niels B

    2010-10-19

    Complex one- or two-dimensional concentration gradients of alkynated molecules are produced on azidized conducting polymer substrates by stenciled "electro click chemistry". The latter describes the local electrochemical generation of catalytically active Cu(I) required to complete a "click reaction" between alkynes and azides at room temperature. A stencil on the counter electrode defines the shape and multiplicity of the gradient(s) on the conducting polymer substrate, while the specific reaction conditions control gradient steepness and the maximum concentration deposited. Biologically active ligands including cell binding peptides are patterned in gradients by this method without losing their biological function or the conductivity of the polymer. PMID:20860406

  7. Blood Coagulation Induced by Iranian Saw-Scaled Viper (Echis Carinatus) Venom: Identification, Purification and Characterization of a Prothrombin Activator

    PubMed Central

    Babaie, Mahdi; Salmanizadeh, Hossein; Zolfagharian, Hossein

    2013-01-01

    Objective(s): Echis carinatus is one of the venomous snakes in Iran. The venom of Iranian Echis carinatus is a rich source of protein with various factors affecting the plasma protein and blood coagulation factor. Some of these proteins exhibit types of enzymatic activities. However, other items are proteins with no enzymatic activity. Materials and Methods: In order to study the mechanism and effect of the venom on human plasma proteins, the present study has evaluated the effect of crude venom and all fractions. A procoagulant factor (prothrombin activator) was isolated from the venom of the Iranian snake Echis carinatus with a combination of gel filtration (Sephadex G-75), ion-exchange chromatography (DEAE- Sepharose) and reverse phase HPLC. Furthermore, proteolytic activity of the crude venom and all fractions on blood coagulation factors such as prothrombin time (PT) was studied. Results: In the present study, the PT test was reduced from 13.4 s to 8.6 s when human plasma was treated with crude venom (concentraion of venom was 1 mg/ml). The purified procoagulant factor revealed a single protein band in SDS polyacrylamide electrophoresis under reducing conditions and its molecular weight was estimated at about 65 kDa. A single-band protein showed fragment patterns similar to those generated by the group A prothrombin activators, which convert prothrombin into meizothrombin independent of the prothrombinase complex. Conclusion: This study showed that the fraction which separated from Iranian snake Echis carinatus venom can be a prothrombin activators. It can be concluded that this fraction is a procoagulant factor. PMID:24494066

  8. Nucleotide sequence of the gene for human prothrombin

    SciTech Connect

    Degen, S.J.F.; Davie, E.W.

    1987-09-22

    A human genomic DNA library was screened for the gene coding for human prothrombin with a cDNA coding for the human protein. Eighty-one positive lambda phage were identified, and three were chosen for further characterization. These three phage hybridized with 5' and/or 3' probes prepared from the prothrombin cDNA. The complete DNA sequence of 21 kilobases of the human prothrombin gene was determined and included a 4.9-kilobase region that was previously sequenced. The gene for human prothrombin contains 14 exons separated by 13 intervening sequences. The exons range in size from 25 to 315 base pairs, while the introns range from 84 to 9447 base pairs. Ninety percent of the gene is composed of intervening sequence. All the intron splice junctions are consistent with sequences found in other eukaryotic genes, except for the presence of GC rather than GT on the 5' end of intervening sequence L. Thirty copies of Alu repetitive DNA and two copies of partial KpnI repeats were identified in clusters within several of the intervening sequences, and these repeats represent 40% of the DNA sequence of the gene. The size, distribution, and sequence homology of the introns within the gene were the compared to those of the genes for the other vitamin K dependent proteins and several other serine proteases.

  9. 21 CFR 864.7720 - Prothrombin consumption test.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Prothrombin consumption test. 864.7720 Section 864.7720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7720...

  10. 21 CFR 864.7720 - Prothrombin consumption test.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Prothrombin consumption test. 864.7720 Section 864.7720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7720...

  11. 21 CFR 864.7720 - Prothrombin consumption test.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Prothrombin consumption test. 864.7720 Section 864.7720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7720...

  12. 21 CFR 864.7720 - Prothrombin consumption test.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prothrombin consumption test. 864.7720 Section 864.7720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7720...

  13. 21 CFR 864.7720 - Prothrombin consumption test.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Prothrombin consumption test. 864.7720 Section 864.7720 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages § 864.7720...

  14. Influence of fibrinogen degradation products on thrombin time, activated partial thromboplastin time and prothrombin time of canine plasma.

    PubMed

    Mischke, R; Wolling, H

    2000-01-01

    To investigate how thrombin time, activated partial thromboplastin time (APTT) and prothrombin time are influenced by fibrinogen degradation products (FDP), different concentrations (0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.8 and 1.0 mg/ml) of the purified FDP X, Y, D and E were added to the plasma of healthy dogs. If fragment Y was added to the plasma a considerable inhibitory effect could be demonstrated for all three test systems. A significant prolongation (p < 0.05) was found for concentrations of > or =0.1 mg/ml (thrombin time, APTT) and > or =0.2 mg/ml (prothrombin time). With FDP Y concentrations from >0.185 mg/ml (prothrombin time) to >0.24 mg/ml (APTT) coagulation time was prolonged beyond the respective reference range. As regards the other fragments, a comparable inhibitory effect could only be shown for fragment X added to the thrombin time test system. This effect can most probably be explained by the competition of the FDP X and fibrinogen for the fibrinogen binding sites of thrombin, rather than by a fibrin polymerization disorder. The results demonstrate that for plasma with normal fibrinogen concentration the group tests are only prolonged beyond the reference range at FDP concentrations very rarely found in spontaneous hyperfibrinolysis. PMID:11014962

  15. Minimal selective concentrations of tetracycline in complex aquatic bacterial biofilms.

    PubMed

    Lundström, Sara V; Östman, Marcus; Bengtsson-Palme, Johan; Rutgersson, Carolin; Thoudal, Malin; Sircar, Triranta; Blanck, Hans; Eriksson, K Martin; Tysklind, Mats; Flach, Carl-Fredrik; Larsson, D G Joakim

    2016-05-15

    Selection pressure generated by antibiotics released into the environment could enrich for antibiotic resistance genes and antibiotic resistant bacteria, thereby increasing the risk for transmission to humans and animals. Tetracyclines comprise an antibiotic class of great importance to both human and animal health. Accordingly, residues of tetracycline are commonly detected in aquatic environments. To assess if tetracycline pollution in aquatic environments promotes development of resistance, we determined minimal selective concentrations (MSCs) in biofilms of complex aquatic bacterial communities using both phenotypic and genotypic assays. Tetracycline significantly increased the relative abundance of resistant bacteria at 10 μg/L, while specific tet genes (tetA and tetG) increased significantly at the lowest concentration tested (1 μg/L). Taxonomic composition of the biofilm communities was altered with increasing tetracycline concentrations. Metagenomic analysis revealed a concurrent increase of several tet genes and a range of other genes providing resistance to different classes of antibiotics (e.g. cmlA, floR, sul1, and mphA), indicating potential for co-selection. Consequently, MSCs for the tet genes of ≤ 1 μg/L suggests that current exposure levels in e.g. sewage treatment plants could be sufficient to promote resistance. The methodology used here to assess MSCs could be applied in risk assessment of other antibiotics as well. PMID:26938321

  16. Effects of oxalate exposure on Madin-Darby canine kidney cells in culture: renal prothrombin fragment-1 mRNA expression.

    PubMed

    Moryama, Manabu T; Domiki, Chizue; Miyazawa, Katsuhito; Tanaka, Tatsuro; Suzuki, Koji

    2005-12-01

    It has been suggested that renal tubular cell damage induced by oxalic acid, one of the components of urinary calculi, may be involved in a variety of ways in the development of urolithiasis. During our study on a calculus related protein, renal prothrombin fragment-1 (RPTF-1), we noted that this is an inflammation related substance that mediates an acute inflammatory reaction, one of the original roles of prothrombin. RPTF-1 is a part of prothrombin that is a coagulation factor known to be expressed in the renal tubule. We examined whether oxalic acid may cause cytotoxic effects on tubular epithelial cells and whether such chemical stimulation may promote the translation of RPTF-1 mRNA into RPTF-1 proteins. We used Madin-Darby canine kidney (MDCK) cells derived from the distal tubule of a dog kidney. In this study, the effects of oxalic acid in culture solution at different concentrations on cytotoxicity were assessed using a MTT assay. The location of active oxygen species was identified using dichlorofluorescein diacetate. After the prothrombin sequence of RPTF-1 was confirmed in MDCK cells, RPTF-1 mRNA expression was determined by RT-PCR. The gene sequence of the same promoter area was ligated, and a luciferase sequence was inserted downstream of the vector. The target sequence was transfected into MDCK cells and the relation between oxalic acid and prothrombin promoter was examined. In addition, the variable expression of RPTF-1 mRNA was quantitatively compared depending on oxalic acid concentrations using real-time PCR. When cytotoxicity was investigated, cells were not damaged but, by contrast, were stimulated and activated under oxalic acid below a certain concentration. The relation between cytotoxicity on the cultured MDCK cell membrane and active oxygen species was confirmed. Luminescence in MDCK cells containing the luciferase gene was detected by the addition of oxalic acid, which activated the prothrombin promoter. A part of the prothrombin gene

  17. Prothrombin Activation by Platelet-associated Prothrombinase Proceeds through the Prethrombin-2 Pathway via a Concerted Mechanism*

    PubMed Central

    Haynes, Laura M.; Bouchard, Beth A.; Tracy, Paula B.; Mann, Kenneth G.

    2012-01-01

    The protease α-thrombin is a key enzyme of the coagulation process as it is at the cross-roads of both the pro- and anti-coagulant pathways. The main source of α-thrombin in vivo is the activation of prothrombin by the prothrombinase complex assembled on either an activated cell membrane or cell fragment, the most relevant of which is the activated platelet surface. When prothrombinase is assembled on synthetic phospholipid vesicles, prothrombin activation proceeds with an initial cleavage at Arg-320 yielding the catalytically active, yet effectively anticoagulant intermediate meizothrombin, which is released from the enzyme complex ∼30–40% of the time. Prothrombinase assembled on the surface of activated platelets has been shown to proceed through the inactive intermediate prethrombin-2 via an initial cleavage at Arg-271 followed by cleavage at Arg-320. The current work tests whether or not platelet-associated prothrombinase proceeds via a concerted mechanism through a study of prothrombinase assembly and function on collagen-adhered, thrombin-activated, washed human platelets in a flow chamber. Prothrombinase assembly was demonstrated through visualization of bound factor Xa by confocal microscopy using a fluorophore-labeled anti-factor Xa antibody, which demonstrated the presence of distinct platelet subpopulations capable of binding factor Xa. When prothrombin activation was monitored at a typical venous shear rate over preassembled platelet-associated prothrombinase neither potential intermediate, meizothrombin or prethrombin-2, was observed in the effluent. Collectively, these findings suggest that platelet-associated prothrombinase activates prothrombin via an efficient concerted mechanism in which neither intermediate is released. PMID:22989889

  18. Growth inhibitory actions of prothrombin on normal hepatocytes: influence of matrix.

    PubMed

    Carr, Brian I; Kar, Siddhartha; Wang, Meifang; Wang, Ziqiu

    2007-09-01

    Most hepatomas have a defect in prothrombin carboxylation, and can secrete under-carboxylated prothrombin or des-gamma-carboxy-prothrombin (DCP), the function of which is unknown. We considered that the prothrombin-DCP axis might also be involved in growth control. Hepatocytes and hepatoma cells were treated with prothrombin and DNA synthesis and cytoskeletal changes were studied. Prothrombin inhibited DNA synthesis in hepatocytes on fibronectin, but not collagen matrix. Hepatoma cell lines were not inhibited. We found that hepatoma cell matrix conferred resistance to hepatocytes. Prothrombin decreased fibronectin but not collagen amounts, but only in the presence of hepatocytes and not hepatoma cells, indicating that it has a differential action on matrix proteins. It also caused changes in cell shape and actin depolymerization. In vivo, there was a decrease in plasma prothrombin activity after a partial hepatectomy (PH), concomitant with the peak of DNA synthesis in the hepatocytes at 24h after PH. Injection of warfarin at the time of PH, further inhibited PT activity and enhanced this 24h peak of DNA synthesis. Furthermore, repeated injection of prothrombin lowered the peak DNA synthesis after PH. The data support the hypothesis that prothrombin can act as a hepatocyte growth inhibitor, likely at the level of fibronectin loss and result in cytoskeletal changes. Hepatomas resist this action, possibly due to their different matrix proteins. This represents a novel mechanism for growth regulation and provides a possible biological significance for the tumor marker DCP. PMID:17490900

  19. Prevalence of the prothrombin G20210A mutation in the Irish populations: use of a novel polymerase chain reaction approach.

    PubMed

    Keenan, C; Livingstone, W J; White, B; Mynett-Johnson, L; Cusack, S; Lawler, M; Smith, O P

    2000-10-01

    The prothrombin G20210A polymorphism is associated with a threefold-increased risk of venous thrombosis. There is considerable variation in the reported prevalence of this polymorphism within normal populations, ranging from 0 to 6.5%. The prevalence within the Irish population has not been determined. A restriction fragment length polymorphism (RFLP)-based assay is commonly used for the detection of the prothrombin 20210A allele. This assay does not include a control restriction digest fragment and, consequently, failure of the enzyme activity or lack of addition of enzyme to the sample cannot be distinguished from wild-type prothrombin. We developed a RFLP-based assay, which incorporates an invariant digest site, resulting in the generation of a control digest fragment. Furthermore, we developed a nested polymerase chain reaction (PCR) method for the amplification and digestion of poor-quality or low-concentration DNA. In the Irish population studied, five of 385 (1.29%) were heterozygous and one patient was homozygous for the prothrombin 20210A polymorphism. This is the first reported data on an Irish or Celtic population and suggests that the allele frequency is similar to Anglo-Saxon populations. The nested PCR method successfully amplified and digested 100/100 (100%) of the archived samples; none of these samples could be analyzed by the standard single-round PCR method. In conclusion, nested PCR should be considered in the analysis of archived samples. Single-round PCR is appropriate for recently collected samples; however, an invariant control digest site should be incorporated in RFLP-based assays to validate the integrity of the digestion enzyme and limit the risk of false-negative results. PMID:11085288

  20. Purification and characterization of multisquamase, the prothrombin activator present in Echis multisquamatus venom.

    PubMed

    Petrovan, R J; Govers-Riemslag, J W; Nowak, G; Hemker, H C; Rosing, J; Tans, G

    1997-11-01

    The venom of Echis multisquamatus (Central Asian sand viper) contains a single prothrombin activator, designated multisquamase, which is structurally and functionally different from ecarin, the prothrombin activator from the venom of Echis carinatus (saw-scaled viper). Multisquamase is comprised of a 58000 Mr and a 23000 Mr subunit that consists of two disulfide-linked chains of 12000 Mr and 10000 Mr, respectively. In contrast to ecarin, which activates prothrombin and prethrombin 1 at comparable rates, and whose activity is hardly affected by Ca2+ or by changes in ionic strength, multisquamase hardly activates prethrombin 1; prothrombin activation requires Ca2+ and is strongly inhibited at high ionic strength. The most favourable kinetic parameters are observed at 1 mM Ca2+ and at low ionic strength (Km=0.085 microM and kcat=0.68 s(-1) at I approximately 0.04). An increase in ionic strength considerably reduces the rate of prothrombin activation, due to an increase of the Km (Km=0.8 microM and kcat=1.03 s(-1) at I approximately 0.2). Studies in plasmas from patients on oral anticoagulant therapy show that E. Multisquamatus venom only activates carboxylated prothrombin, whereas E. carinatus activates both prothrombin and descarboxyprothrombin. Thus, multisquamase-dependent prothrombin activation appears to require post-translational modification of the gla-domain. This venom prothrombin activator may, therefore, become a useful tool to quantitate prothrombin and descarboxyprothrombin in cases where vitamin K-dependent carboxylation of prothrombin is impaired. PMID:9526951

  1. Space charges and defect concentration profiles at complex oxide interfaces

    NASA Astrophysics Data System (ADS)

    Gunkel, Felix; Waser, Rainer; Ramadan, Amr H. H.; De Souza, Roger A.; Hoffmann-Eifert, Susanne; Dittmann, Regina

    2016-06-01

    We discuss electronic and ionic defect concentration profiles at the conducting interface between the two wide-band-gap insulators LaAlO3 and SrTiO3 (STO). The profiles are deduced from a thermodynamic model considering a local space charge layer (SCL) originating from charge transfer to the interface region, thus combining electronic and ionic reconstruction mechanisms. We show that the electrical potential confining the two-dimensional electron gas (2DEG) at the interface modifies the equilibrium defect concentrations in the SCL. For the n -conducting interface, positively charged oxygen vacancies are depleted within the SCL, while negatively charged strontium vacancies accumulate. Charge compensation within the SCL is achieved by a mixed ionic-electronic interface reconstruction, while the competition between 2DEG and localized ionic defects is controlled by ambient p O2 . The concentration of strontium vacancies increases drastically in oxidizing conditions and exhibits a steep depth profile towards the interface. Accounting for the low cation diffusivity in STO, we also discuss kinetic limitations of cation defect formation and the effect of a partial equilibration of the cation sublattice. We discuss the resulting implications for low temperature transport.

  2. Lithium concentration and Li isotopic compositions of carbonatitic complexes

    NASA Astrophysics Data System (ADS)

    Halama, R.; McDonough, W. F.; Rudnick, R. L.; Ash, R. D.; Keller, J.; Klaudius, J.; Trumbull, R.

    2005-12-01

    To evaluate the Li isotopic signatures of the mantle sources of carbonatites and the influence of magmatic differentiation and post-magmatic processes on δ7Li, we determined the Li concentrations and isotopic compositions of carbonatites and spatially associated silicate rocks, spanning a wide range in composition and age. Natrocarbonatites from Oldoinyo Lengai (1995 and 2000 eruptions) have high Li concentrations (211-292 ppm) and uniform Li isotopic signatures (δ7Li = +4.4 to +5.1 per mil). Associated silicate rocks (melilitite, nephelinite and phonolite) have lower Li concentrations (16-47 ppm) and trend towards lighter Li isotopic values (δ7Li = 0 to +3.5 per mil). Clinopyroxenes from these lavas are significantly lighter than the whole rocks by 1 to 6 per mil. Since the lavas appear to be fresh, this suggests fractionation of Li isotopes between minerals and whole rocks. In comparison to the modern natrocarbonatites, Proterozoic calciocarbonatites from Greenland (Grønnedal-Ika) and Cretaceous calciocarbonatites from Namibia (Kalkfeld) are poor in Li (< 2 ppm) and have more scattered Li isotopic compositions (δ7Li = -1 to +4 and -0.5 to +5 per mil, respectively). The lower δ7Li values may reflect contamination by crustal Li, since the low Li contents in the carbonatites make them susceptible to this. Silicate lavas from Kalkfeld have higher Li concentrations (11-12 ppm) than their associated carbonatites, but overlapping isotopic compositions (δ7Li = +4 to +6 per mil). At Grønnedal-Ika, clinopyroxene separates from nepheline syenites vary considerably in δ7Li from -6 to +5. Since Li is preferentially partitioned into fenitizing fluids [1] and an enrichment of light 6Li in fluids during degassing can be anticipated [2], the trend towards negative δ7Li can be interpreted as a result of variable interaction with metasomatizing fluids. However, fractionation of Li isotopes between minerals and melts may also have played a role. Our preliminary data

  3. Recovery of cobalt and copper from complex sulfide concentrates

    SciTech Connect

    Dannenberg, R.O.; Gardner, P.C.; Crane, S.R.; Seidel, D.C.

    1987-01-01

    The Bureau conducted bench-scale research on a process for treating cobaltite concentrates, comprising (1) oxidative pressure leaching, (2) jarosite precipitation followed by H/sub 2/O/sub 2/ oxidation and pH control to remove iron and arsenic, (3) copper solvent extraction with a mixed hydroxyoxime-amine extractant, (4) copper electrowinning from recirculating acidic strip liquor, (5) selective cobalt extraction from copper solvent extraction raffinate with a phosphinic and extractant, and (6) electrowinning of cobalt from a recirculating weak acid strip liquor. Overall cobalt and copper recoveries were 91.7 and 84.1 pct, respectively. Electrowon products assayed 99.8 pct Co and 99.89 ct Cu.

  4. Prothrombin carora: hypoprothrombinaemia caused by substitution of Tyr-44 by Cys.

    PubMed

    Sun, W Y; Ruiz-Saez, A; Burkart, M C; Bosch, N; Degen, S J

    1999-06-01

    Two members of a family from Carora, Venezuela, were found to have prothrombin activity levels at 4% of normal and undetectable antigen levels. All exons of the prothrombin gene from the proband were sequenced and a mutation at nucleotide 1305 was identified that would result in the substitution of Cys for Tyr at residue 44. Residue 44 is present in the aromatic stack region of the protein. Substitution of a Cys in this region would result in an abnormal folding of the protein which could be the cause for the observed lack of secretion of the abnormal prothrombin. PMID:10354129

  5. Test procedures and instructions for Hanford complexant concentrate supernatant cesium removal using CST

    SciTech Connect

    Hendrickson, D.W.

    1997-01-08

    This document provides specific test procedures and instructions to implement the test plan for the preparation and conduct of a cesium removal test, using Hanford Complexant Concentrate supernatant liquor from tank 241-AN-107, in a bench-scale column. The cesium sorbent to be tested is crystalline silicotitanate. The test plan for which this provides instructions is WHC-SD-RE-TP-023, Hanford Complexant Concentrate Supernatant Cesium Removal Test Plan.

  6. The linker connecting the two kringles plays a key role in prothrombin activation

    PubMed Central

    Pozzi, Nicola; Chen, Zhiwei; Pelc, Leslie A.; Shropshire, Daniel B.; Di Cera, Enrico

    2014-01-01

    The zymogen prothrombin is proteolytically converted by factor Xa to the active protease thrombin in a reaction that is accelerated >3,000-fold by cofactor Va. This physiologically important effect is paradigmatic of analogous cofactor-dependent reactions in the coagulation and complement cascades, but its structural determinants remain poorly understood. Prothrombin has three linkers connecting the N-terminal Gla domain to kringle-1 (Lnk1), the two kringles (Lnk2), and kringle-2 to the C-terminal protease domain (Lnk3). Recent developments indicate that the linkers, and particularly Lnk2, confer on the zymogen significant flexibility in solution and enable prothrombin to sample alternative conformations. The role of this flexibility in the context of prothrombin activation was tested with several deletions. Removal of Lnk2 in almost its entirety (ProTΔ146–167) drastically reduces the enhancement of thrombin generation by cofactor Va from >3,000-fold to 60-fold because of a significant increase in the rate of activation in the absence of cofactor. Deletion of Lnk2 mimics the action of cofactor Va and offers insights into how prothrombin is activated at the molecular level. The crystal structure of ProTΔ146–167 reveals a contorted architecture where the domains are not vertically stacked, kringle-1 comes within 9 Å of the protease domain, and the Gla-domain primed for membrane binding comes in contact with kringle-2. These findings broaden our molecular understanding of a key reaction of the blood coagulation cascade where cofactor Va enhances activation of prothrombin by factor Xa by compressing Lnk2 and morphing prothrombin into a conformation similar to the structure of ProTΔ146–167. PMID:24821807

  7. Preparation of factor VII concentrate using CNBr-activated Sepharose 4B immunoaffinity chromatography

    PubMed Central

    Mousavi Hosseini, Kamran; Nasiri, Saleh

    2015-01-01

    Background: Factor VII concentrates are used in patients with congenital or acquired factor VII deficiency or treatment of hemophilia patients with inhibitors. In this research, immunoaffinity chromatography was used to purify factor VII from prothrombin complex (Prothrombin- Proconvertin-Stuart Factor-Antihemophilic Factor B or PPSB) which contains coagulation factors II, VII, IX and X. The aim of this study was to improve purity, safety and tolerability as a highly purified factor VII concentrate. Methods: PPSB was prepared using DEAE-Sephadex and was used as the starting material for purification of coagulation factor VII. Prothrombin complex was treated by solvent/detergent at 24°C for 6 h with constant stirring. The mixture of PPSB in the PBS buffer was filtered and then chromatographed using CNBr-activated Sepharose 4B coupled with specific antibody. Factors II, IX, VII, X and VIIa were assayed on the fractions. Fractions of 48-50 were pooled and lyophilized as a factor VII concentrate. Agarose gel electrophoresis was performed and Tween 80 was measured in the factor VII concentrate. Results: Specific activity of factor VII concentrate increased from 0.16 to 55.6 with a purificationfold of 347.5 and the amount of activated factor VII (FVIIa) was found higher than PPSB (4.4-fold). Results of electrophoresis on agarose gel indicated higher purity of Factor VII compared to PPSB; these finding revealed that factor VII migrated as alpha-2 proteins. In order to improve viral safety, solvent-detergent treatment was applied prior to further purification and nearly complete elimination of tween 80 (2 μg/ml). Conclusion: It was concluded that immuonoaffinity chromatography using CNBr-activated Sepharose 4B can be a suitable choice for large-scale production of factor VII concentrate with higher purity, safety and activated factor VII. PMID:26034723

  8. Prothrombin C20209T mutation in deep vein thrombosis: a case report

    PubMed Central

    Muñoz, Mariela; Vilos, Cristian; Cantín, Mario

    2015-01-01

    Thrombophilias is a recognized risk factor for thrombotic events. The prothrombin variant G20210A gene mutation has been commonly examined using polymerase chain reaction (PCR). Currently, in many clinical laboratories, performing the PCR in real-time technique, which, in addition to identifying the G20210A mutation, makes possible the detection of other mutations in the 3’UTR of the prothrombin gene by melting curve analysis, due to the ability of this analysis to be amplicon-dependent (e.g., C20209T, C20221T and A20218G). We report the first case in Chile that describes the atypical prothrombin C20209T mutation, in a 50-year-old male patient diagnosed with deep vein thrombosis in the lower limb and family history of thrombophilia. In the literature, there are few studies of the prevalence and functionality of this mutation; its association with thrombotic events is controversial. PMID:26379928

  9. Effect of salt and surfactant concentration on the structure of polyacrylate gel/surfactant complexes.

    PubMed

    Nilsson, Peter; Unga, Johan; Hansson, Per

    2007-09-20

    Small-angle X-ray scattering was used to elucidate the structure of crosslinked polyacrylate gel/dodecyltrimethylammonium bromide complexes equilibrated in solutions of varying concentrations of surfactant and sodium bromide (NaBr). Samples were swollen with no ordering (micelle free), or they were collapsed with either several distinct peaks (cubic Pm3n) or one broad correlation peak (disordered micellar). The main factor determining the structure of the collapsed complexes was found to be the NaBr concentration, with the cubic structure existing up to approximately 150 mM NaBr and above which only the disordered micellar structure was found. Increasing the salt concentration decreases the polyion mediated attractive forces holding the micelles together causing swelling of the gel. At sufficiently high salt concentration the micelle-micelle distance in the gel becomes too large for the cubic structure to be retained, and it melts into a disordered micellar structure. As most samples were above the critical micelle concentration, the bulk of the surfactant was in the form of micelles in the solution and the surfactant concentration thereby had only a minor influence on the structure. However, in the region around 150 mM NaBr, increasing the surfactant concentration, at constant NaBr concentration, was found to change the structure from disordered micellar to ordered cubic and back to disordered again. PMID:17715959

  10. Interference of M-protein on prothrombin time test – case report

    PubMed Central

    Margetić, Sandra; Ćelap, Ivana; Dukić, Lora; Vukasović, Ines; Virović-Jukić, Lucija

    2016-01-01

    The aim of this report was to present a case of interference on prothrombin time (PT) test that directed further laboratory diagnostics and resulted with final detection of monoclonal gammopathy in an 88-year old man. Routine coagulation testing during medical examination at Emergency Department revealed unmeasurable PT (< 7% activity) and activated partial thromboplastin time (aPTT) within reference range. After repeated sampling for coagulation testing, PT was unmeasurable again, as well as fibrinogen level (< 0.8 g/L), thrombin time (TT) was significantly prolonged (107 seconds) and aPTT was within reference range. In both plasma samples refrigerated at 4 ˚C overnight, white gelatinous precipitate was visible between the cell and plasma layers and the presence of monoclonal protein (M-protein) was suggested in our patient. Further laboratory diagnostics revealed total serum proteins at concentration of 123 g/L and the presence of M-protein IgG lambda (λ) at concentration of 47.1 g/L. These results suggested monoclonal gammopathy as an underlying pathophysiological condition in our patient. Activities of coagulation factors II, V, VII and X were within reference ranges or increased. These results and correction of unmeasurable PT result to 67% in mixing test with commercial normal plasma suggest in vitro rather than in vivo interference of M-protein on PT result. In contrast, significantly prolonged TT results in all analysed samples suggest impact of M-protein on this global coagulation test due to possible effect on fibrin polymerization. PMID:27346971

  11. X-ray Absorption Spectroscopy Identifies Calcium-Uranyl-Carbonate Complexes at Environmental Concentrations

    SciTech Connect

    Kelly, Shelly D; Kemner, Kenneth M; Brooks, Scott C

    2007-01-01

    Current research on bioremediation of uranium-contaminated groundwater focuses on supplying indigenous metal-reducing bacteria with the appropriate metabolic requirements to induce microbiological reduction of soluble uranium(VI) to poorly soluble uranium(IV). Recent studies of uranium(VI) bioreduction in the presence of environmentally relevant levels of calcium revealed limited and slowed uranium(VI) reduction and the formation of a Ca-UO2-CO3 complex. However, the stoichiometry of the complex is poorly defined and may be complicated by the presence of a Na-UO2-CO3 complex. Such a complex might exist even at high calcium concentrations, as some UO2-CO3 complexes will still be present. The number of calcium and/or sodium atoms coordinated to a uranyl carbonate complex will determine the net charge of the complex. Such a change in aqueous speciation of uranium(VI) in calcareous groundwater may affect the fate and transport properties of uranium. In this paper, we present the results from X-ray absorption fine structure (XAFS) measurements of a series of solutions containing 50 lM uranium(VI) and 30 mM sodium bicarbonate, with various calcium concentrations of 0-5 mM. Use of the data series reduces the uncertainty in the number of calcium atoms bound to the UO2-CO3 complex to approximately 0.6 and enables spectroscopic identification of the Na-UO2-CO3 complex. At nearly neutral pH values, the numbers of sodium and calcium atoms bound to the uranyl triscarbonate species are found to depend on the calcium concentration, as predicted by speciation calculations.

  12. X-ray absorption spectroscopy identifies calcium-uranyl-carbonate complexes at environmental concentrations.

    SciTech Connect

    Kelly, S. D.; Kemner, K. M.; Brooks, S. C.; Biosciences Division; ORNL

    2007-01-01

    Current research on bioremediation of uranium-contaminated groundwater focuses on supplying indigenous metal-reducing bacteria with the appropriate metabolic requirements to induce microbiological reduction of soluble uranium(VI) to poorly soluble uranium(IV). Recent studies of uranium(VI) bioreduction in the presence of environmentally relevant levels of calcium revealed limited and slowed uranium(VI) reduction and the formation of a Ca-UO{sub 2}-CO{sub 3} complex. However, the stoichiometry of the complex is poorly defined and may be complicated by the presence of a Na-UO{sub 2}-CO{sub 3} complex. Such a complex might exist even at high calcium concentrations, as some UO{sub 2}-CO{sub 3} complexes will still be present. The number of calcium and/or sodium atoms coordinated to a uranyl carbonate complex will determine the net charge of the complex. Such a change in aqueous speciation of uranium(VI) in calcareous groundwater may affect the fate and transport properties of uranium. In this paper, we present the results from X-ray absorption fine structure (XAFS) measurements of a series of solutions containing 50 {micro}M uranium(VI) and 30 mM sodium bicarbonate, with various calcium concentrations of 0-5 mM. Use of the data series reduces the uncertainty in the number of calcium atoms bound to the UO{sub 2}-CO{sub 3} complex to approximately 0.6 and enables spectroscopic identification of the Na-UO{sub 2}-CO{sub 3} complex. At nearly neutral pH values, the numbers of sodium and calcium atoms bound to the uranyl triscarbonate species are found to depend on the calcium concentration, as predicted by speciation calculations.

  13. A Point-of-Care Prothrombin Time Test on a Microfluidic Disk Analyzer Using Alternate Spinning.

    PubMed

    Lin, Chia-Hui; Lin, Kun-Wei; Yen, Daniel; Shih, Chih-Hsin; Lu, Chien-Hsing; Wang, Jiunn-Min; Lin, Chi-Yu

    2015-02-01

    In this study, we conducted a fully integrated point-of-care prothrombin time test on a microfluidic disk analyzer. The microfluidic functions integrated on the disk were capable of separating whole blood, decanting plasma, and mixing it with reagents in sequence under alternate spinning. The assay protocol was completed by alternate spinning without using microvalves or surface modification. Clinical sample tests on prothrombin time measurement were conducted by both the microfluidic disk analyzer and the reference instrument used in medical centers. The test results showed a good correlation and agreement between the two instruments. PMID:26353663

  14. Amino acid sequence of a vitamin K-dependent Ca2+-binding peptide from bovine prothrombin.

    PubMed

    Howard, J B; Fausch, M D

    1975-08-10

    The amino acid sequence of a 31-residue peptide from bovine prothrombin has been determined. This peptide has been shown to contain the vitamin K-dependent modification required for Ca2+ binding (Nelsestuen, G. L., and Suttie, J. W. (1973) Proc. Natl. Acad. Sci. U. S. A. 70, 3366-3370) and the modified amino acid, gamma-carboxyglutamic acid (Nelsestuen, G. L., Zytkovicz, T., and Howard, J. B. (1974) J. Biol. Chem. 249, 6347-6350). The peptide was shown to correspond to residues 12 to 42 of prothrombin. PMID:807581

  15. [Evaluation of penicillin expandase mutants and complex substrate inhibition characteristics at high concentrations of penicillin G].

    PubMed

    Wu, Linjun; Fan, Keqiang; Ji, Junjie; Yang, Keqian

    2015-12-01

    Penicillin expandase, also known as deacetoxycephalosporin C synthase (DAOCS), is an essential enzyme involved in cephalosporin C biosynthesis. To evaluate the catalytic behaviors of penicillin expandase under high penicillin G concentration and to identify mutants suitable for industrial applications, the specific activities of wild-type DAOCS and several mutants with increased activities toward penicillin G were determined by HPLC under high penicillin G concentrations. Their specific activity profiles were compared with theoretical predictions by different catalytic dynamics models. We evaluated the specific activities of wild-type DAOCS and previous reported high-activity mutants H4, H5, H6 and H7 at concentrations ranging from 5.6 to 500 mmol/L penicillin G. The specific activities of wild-type DAOCS and mutant H4 increased as penicillin G concentration increased, but decreased when concentrations of substrate go above 200 mmol/L. Other mutants H5, H6 and H7 showed more complex behaviors under high concentration of penicillin G. Among all tested enzymes, mutant H6 showed the highest activity when concentration of penicillin G is above 100 mmol/L. Our results revealed that the substrate inhibition to wild-type DAOCS' by penicillin G is noncompetitive. Other DAOCS mutants showed more complex trends in their specific activities at high concentration of penicillin G (>100 mmol/L), indicating more complex substrate inhibition mechanism might exist. The substrate inhibition and activity of DAOCS mutants at high penicillin G concentration provide important insight to help select proper mutants for industrial application. PMID:27093832

  16. METEOROLOGICAL EVENTS THAT PRODUCED THE HIGHEST GROUND-LEVEL CONCENTRATIONS DURING COMPLEX TERRAIN FIELD EXPERIMENTS

    EPA Science Inventory

    The U.S. Environmental Protection Agency (EPA) is sponsoring the Complex Terrain Model Development project, a multi-year study to develop improved models for calculating ground-level air pollutant concentrations that result from large emission sources located in mountainous terra...

  17. Global prevalence of prothrombin gene mutation G20210A and implications in women's health: a systematic review.

    PubMed

    Dziadosz, Margaret; Baxi, Laxmi V

    2016-07-01

    Distribution of hereditary thrombophilic gene mutations differs globally. Prothrombin gene mutation G20210A is a common prothrombotic single-nucleotide polymorphism. In this systematic review, we provide a comprehensive report of the prevalence of prothrombin G20210A across the globe. Databases [Pubmed, Web of Science, Embase] were interrogated from their inception through December 2015 for articles reporting prothrombin G20210A prevalence rates and ethnicity. Prevalence rates were organized by continent and ethnoracial ancestry. A total of 113 articles were included with a total 61 876 participants tested for prothrombin G20210A. Reported prevalence rates varied from 0 to 15.9% among ethnic groups, with higher rates seen in the thromboembolism affected cohort compared with the unaffected cohort. Carrier rate distribution is supported by known historical migration patterns of global populations. This review of prothrombin G20210A prevalence may guide resourceful screening for identification of hereditary thrombophilia in female populations of interest with hypercoagulable states. PMID:27058219

  18. Influence of Structure, Charge, and Concentration on the Pectin-Calcium-Surfactant Complexes.

    PubMed

    Joshi, Nidhi; Rawat, Kamla; Bohidar, H B

    2016-05-12

    Polymer-surfactant complex formation of pectin with different types of surfactants, cationic (cetyltrimethylammonium bromide, CTAB and dodecyl trimethylammonium bromide, DTAB), anionic (sodium dodecyl sulfate, SDS), and neutral (Triton X-100, TX-100), was investigated at room temperature in the presence and absence of cross-linker calcium chloride using light scattering, zeta potential, rheology, and UV-vis spectroscopic measurements where the surfactant concentration was maintained below their critical micellar concentration (CMC). Results indicated that the interaction of cationic surfactant with pectin in the presence and absence of calcium chloride was much stronger compared to anionic and neutral surfactants. The neutral surfactant showed identifiable interaction despite the absence of any charged headgroup, while anionic surfactant showed feeble or very weak interaction with the polymer. The pectin-CTAB or DTAB complex formation was attributed to associative electrostatic and hydrophobic interactions. On comparison between the cationic surfactants, it was found that CTAB interacts strongly with pectin because of its long hydrocarbon chain. The morphology of complexes formed exhibited random coil structures while at higher concentration of surfactant, rod-like or extended random coil structures were noticed. Thus, functional characteristics of the complex could be tuned by varying the type of surfactant (charge and structure) and its concentration. The differential network rigidity (pectin-CTAB versus pectin-DTAB gels) obtained from rheology measurements showed that addition of a very small amount of surfactant (concentration ≪ CMC) was required for enhancing network strength, while the presence of a large amount of surfactant resulted in the formation of fragile gels. No gel formation occurred when the surfactant concentration was close to their CMC values. Considering the importance of pectin in food and pharmaceutical industry, this study is relevant

  19. Limiting prothrombin activation to meizothrombin is compatible with survival but significantly alters hemostasis in mice.

    PubMed

    Shaw, Maureen A; Kombrinck, Keith W; McElhinney, Kathryn E; Sweet, David R; Flick, Matthew J; Palumbo, Joseph S; Cheng, Mei; Esmon, Naomi L; Esmon, Charles T; Brill, Alexander; Wagner, Denisa D; Degen, Jay L; Mullins, Eric S

    2016-08-01

    Thrombin-mediated proteolysis is central to hemostatic function but also plays a prominent role in multiple disease processes. The proteolytic conversion of fII to α-thrombin (fIIa) by the prothrombinase complex occurs through 2 parallel pathways: (1) the inactive intermediate, prethrombin; or (2) the proteolytically active intermediate, meizothrombin (fIIa(MZ)). FIIa(MZ) has distinct catalytic properties relative to fIIa, including diminished fibrinogen cleavage and increased protein C activation. Thus, fII activation may differentially influence hemostasis and disease depending on the pathway of activation. To determine the in vivo physiologic and pathologic consequences of restricting thrombin generation to fIIa(MZ), mutations were introduced into the endogenous fII gene, resulting in expression of prothrombin carrying 3 amino acid substitutions (R157A, R268A, and K281A) to limit activation events to yield only fIIa(MZ) Homozygous fII(MZ) mice are viable, express fII levels comparable with fII(WT) mice, and have reproductive success. Although in vitro studies revealed delayed generation of fIIa(MZ) enzyme activity, platelet aggregation by fII(MZ) is similar to fII(WT) Consistent with prior analyses of human fIIa(MZ), significant prolongation of clotting times was observed for fII(MZ) plasma. Adult fII(MZ) animals displayed significantly compromised hemostasis in tail bleeding assays, but did not demonstrate overt bleeding. More notably, fII(MZ) mice had 2 significant phenotypic advantages over fII(WT) animals: protection from occlusive thrombosis after arterial injury and markedly diminished metastatic potential in a setting of experimental tumor metastasis to the lung. Thus, these novel animals will provide a valuable tool to assess the role of both fIIa and fIIa(MZ) in vivo. PMID:27252233

  20. Measuring complex for studying cascade solar photovoltaic cells and concentrator modules on their basis

    NASA Astrophysics Data System (ADS)

    Larionov, V. R.; Malevskii, D. A.; Pokrovskii, P. V.; Rumyantsev, V. D.

    2015-06-01

    The design and implementation of several measuring complexes intended for studying cascade solar photovoltaic converters are considered. The complexes consist of a solar simulator and an electronic unit with an active load. The high-aperture light source of the complex reproduces solar intensity over wide spectral range λ = 350-1700 nm with an angle of divergence of ±0.26°, which are characteristic of solar radiation. The active load of the electronic unit allows taking both dark and illuminated I- V characteristics of test objects within about 1 ms during the quasi-stationary part of the irradiation pulse. The small size and low power consumption of the complexes hold out the hope that they will be widely used in designing, refining, and testing cascade efficient photovoltaic converters made of III-V materials and solar modules integrating these converters with concentrator modules.

  1. 21 CFR 864.7735 - Prothrombin-proconvertin test and thrombotest.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Prothrombin-proconvertin test and thrombotest. 864.7735 Section 864.7735 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages §...

  2. 21 CFR 864.7735 - Prothrombin-proconvertin test and thrombotest.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Prothrombin-proconvertin test and thrombotest. 864.7735 Section 864.7735 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages §...

  3. 21 CFR 864.7735 - Prothrombin-proconvertin test and thrombotest.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Prothrombin-proconvertin test and thrombotest. 864.7735 Section 864.7735 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages §...

  4. 21 CFR 864.7735 - Prothrombin-proconvertin test and thrombotest.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Prothrombin-proconvertin test and thrombotest. 864.7735 Section 864.7735 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages §...

  5. 21 CFR 864.7735 - Prothrombin-proconvertin test and thrombotest.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Prothrombin-proconvertin test and thrombotest. 864.7735 Section 864.7735 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Hematology Kits and Packages §...

  6. Decrease in antithrombin III and prothrombin serum levels contribute to coagulation disorders during leptospirosis.

    PubMed

    Fernandes, Luis G V; Filho, Antonio F S; Souza, Gisele O; Vasconcellos, Silvio A; Romero, Eliete C; Nascimento, Ana L T O

    2016-08-01

    Pathogenic bacteria of the genus Leptospira are the causative agent of leptospirosis, an emergent infectious disease that affects humans and animals worldwide. Severe forms of the disease in humans include jaundice, multiple organ failure and intense haemorrhage. Up to now, mechanisms associated with the haemorrhage foci are poorly understood. We report in this work that, despite the low levels of antithrombin III in convalescent human serum samples, virulent, culture-attenuated and saprophyte strains of Leptospira are unable to bind and/or degrade this thrombin inhibitor, suggesting an indirect mechanism of pathogenesis. Lower levels of prothrombin were found in serum samples at the onset and convalescent phase of the disease when compared to normal human sera. The concomitant decreased levels of antithrombin III and prothrombin suggest a process of stimulated coagulation, which is corroborated by the increase of prothrombin fragment F1+2 in the serum samples. Data obtained with hamsters experimentally infected with virulent Leptospira interrogans serovars Kennewicki and Canicola strongly point out that haemorrhage is correlated with decreased levels of thrombin inhibitors and prothrombin. Activated coagulation might lead to an overconsumption of coagulation factors ultimately leading to bleeding and organ failure. PMID:27260249

  7. The Aqueous Thermodynamics and Complexation Reactions of Anionic Silica and Uranium Species to High Concentration

    SciTech Connect

    Felmy, Andrew R.

    2004-06-01

    Highly basic tank wastes contain several important radionuclides, including 90Sr, 99Tc, and 60Co, as well as actinide elements (i.e., isotopes of U, Pu, and Am). These highly basic tank wastes are known to have leaked into the vadose zone at the Hanford Site. Upon entering the sediments in the vadose zone, the highly basic solutions dissolve large concentrations of silica from the silica and aluminosilicate minerals present in the subsurface. These dissolution reactions alter the chemical composition of the leaking solutions, transforming them from a highly basic (as high 2M NaOH) solution into a pore solution with a very high concentration of dissolved silica and a significantly reduced pH. This moderately basic (pH 9 to 11), high-silica solution has the potential to complex radionuclides and move through the subsurface. Such strong radionuclide complexation is a currently unconsidered transport vector that has the potential to expedite radionuclide transport through the vad ose zone. These strong complexation effects have the ability to significantly alter current conceptual models of contaminant migration beneath leaking tanks. In this project, we are determining the aqueous thermodynamics and speciation of dissolved silica and silica-radionuclide complexes to high silica concentration. We are also initiating studies of U(VI) speciation under strongly basic conditions.

  8. Thermodynamic modeling of neptunium(V)-acetate complexation in concentrated NaCl media

    SciTech Connect

    Novak, C.F.; Borkowski, M.; Choppin, G.R.

    1995-09-01

    The complexation of neptunium(V), Np(V), with the acetate anion, Ac{sup -}, was measured in sodium chloride media to high concentration using an extraction technique. The data were interpreted using the thermodynamic formalism of Pitzer, which is valid to high electrolyte concentrations. A consistent model for the deprotonation constants of acetic acid in NaCl and NaClO{sub 4} media was developed. For the concentrations of acetate expected in a waste repository, only the neutral complex NpO{sub 2}Ac(aq) was important in describing the interactions between the neptunyl ion and acetate. The thermodynamic stability constant log {beta}{sup 0}{sub 101} for the reaction NpO{sub 2}{sup +} + Ac{sup -} {leftrightarrow} NpO{sub 2}Ac was calculated to be 1.46{plus_minus}0.11. This weak complexing behavior between the neptunyl ion and acetate indicates that acetate will not significantly enhance dissolved Np(V) concentrations in ground waters associated with nuclear waste repositories that may contain acetate.

  9. An Aqueous Thermodynamic Model for the Complexation of Nickel with EDTA Valid to high Base Concentration

    SciTech Connect

    Felmy, Andrew R.; Qafoku, Odeta

    2004-09-01

    An aqueous thermodynamic model is developed which accurately describes the effects of high base concentration on the complexation of Ni2+ by ethylenedinitrilotetraacetic acid (EDTA). The model is primarily developed from an extensive data on the solubility of Ni(OH)2(c) in the presence of EDTA and in the presence and absence of Ca2+ as the competing metal ion. The solubility data for Ni(OH)2(c) were obtained in solutions ranging in NaOH concentration from 0.01 to 11.6m, and in Ca 2+ concentrations extending to saturation with respect to portlandite, Ca(OH)2. Owing to the inert nature of the Ni-EDTA complexation reactions, solubility experiments were approached from both the oversaturation and undersaturation direction and over time frames extending to 413 days. The final aqueous thermodynamic model is based upon the equations of Pitzer, accurately predicts the observed solubilities to concentrations as high as 11.6m NaOH, and is consistent with UV-Vis spectroscopic studies of the complexes in solution.

  10. Prothrombin Gene G20210A Mutation in Acute Deep Venous Thrombosis Patients with Poor Response to Warfarin Therapy

    PubMed Central

    Attia, F.M; Mikhailidis, D.P; Reffat, S.A

    2009-01-01

    Aim: The pathogenesis of deep venous thrombosis (DVT) involves an interaction between hereditary and acquired factors. Prothrombin gene mutation is one of the hereditary risk factors. We evaluated the frequency of the prothrombin gene mutation in patients with DVT and its relation to oral warfarin anticoagulant therapy response. Methods: Prothrombin gene mutation was looked for in 40 DVT patients with poor response to warfarin. The results were compared with 40 DVT patients with a normal response to warfarin and 30 healthy blood donors. Blood samples were also assessed for protein C, protein S, anti-thrombin III and anticardiolipin antibodies (ACA) levels. Results: Prothrombin gene mutation was found in normal and poor DVT responders (6/40 and 13/40, respectively; p = NS) as well as in healthy controls (1/30). Patients with recurrent DVT or a family history of DVT were significantly (p<0.0001) more likely to have the prothrombin mutation than other DVT patients. Non prothrombin abnormalities (protein C, anti-thrombin III and ACA) were more common in poor responders than controls (p<0.0037) as were ACA (p<0.034). Conclusions: Prothrombin gene mutation is present in several DVT patients, especially those with recurrent DVT or a family history of DVT. This mutation may contribute to a poor response to warfarin. PMID:19920886

  11. Concentration measurements of complex mixtures of broadband absorbers by widely tunable optical parametric oscillator laser spectroscopy

    NASA Astrophysics Data System (ADS)

    Ruxton, K.; Macleod, N. A.; Weidmann, D.; Malcolm, G. P. A.; Maker, G. T.

    2012-11-01

    The ability to obtain accurate vapour parameter information from a compound's absorption spectrum is an essential data processing application in order to quantify the presence of an absorber. Concentration measurements can be required for a variety of applications including environmental monitoring, pipeline leak detection, surface contamination and breath analysis. This work demonstrates sensitive concentration measurements of complex mixtures of volatile organic compounds (VOCs) using broadly tunable mid wave infrared (MWIR) laser spectroscopy. Due to the high absorption cross-sections, the MWIR spectral region is ideal to carry out sensitive concentration measurements of VOCs by tunable laser absorption spectroscopy (TLAS) methods. Absorption spectra of mixtures of VOCs were recorded using a MWIR optical parametric oscillator (OPO), with a tuning range covering 2.5 μm to 3.7 μm. The output of the MWIR OPO was coupled to a multi-pass astigmatic Herriott gas cell, maintained at atmospheric pressure that can provide up to 210 m of absorption path length, with the transmission output from the cell being monitored by a detector. The resulting spectra were processed by a concentration retrieval algorithm derived from the optimum estimation method, taking into account both multiple broadband absorbers and interfering molecules that exhibit narrow multi-line absorption features. In order to demonstrate the feasibility of the concentration measurements and assess the capability of the spectral processor, experiments were conducted on calibrated VOCs vapour mixtures flowing through the spectroscopic cell with concentrations ranging from parts per billion (ppb) to parts per million (ppm). This work represents as a first step in an effort to develop and apply a similar concentration fitting algorithm to hyperspectral images in order to provide concentration maps of the spatial distribution of multi-species vapours. The reported functionality of the novel fitting algorithm

  12. Evaluation of the Use of Complex Mineral Concentrate as a Modifier Steel

    NASA Astrophysics Data System (ADS)

    Gizatulin, R. A.; Fedoseev, S. N.; Dariev, R. S.

    2016-04-01

    Increasing customer demands for quality of the resulting metal, and in the first place, the impurities, metallurgists dictate need to develop new and improved technologies. Thus, a significant reduction in metal losses can be achieved by developing new complex alloy steels, special purpose, improving technology of their production and developing new technology of smelting to improve the physical, mechanical, foundry and operational characteristics by influencing the structure of the steel by modifying the liquid melt, change more favorable morphology of nonmetallic inclusions. For complex-alloyed steels expensive and scarce alloying elements Ti, Nb, Zr, etc., are used, which are inaccessible to conventional structural steels. In this regard, the paper also presents the results of applying of innovative modifiers containing alloying elements (Ti, Nb, Zr, etc.) based on mineral concentrates in the Tomsk region.

  13. The prothrombin gene G20210A variant: prevalence in a U.K. anticoagulant clinic population.

    PubMed

    Cumming, A M; Keeney, S; Salden, A; Bhavnani, M; Shwe, K H; Hay, C R

    1997-08-01

    We have investigated the prevalence of a recently reported genetic variation in the prothrombin gene (G20210A) in patients with an objectively confirmed history of venous thrombosis, 12/219 patients (5.5%) were found to be heterozygous carriers of the 20210A allele. The incidence of the 20210A allele in a group of 164 healthy controls was 1.2% (allele frequency 0.61%, 95% CI 0.08-2.19). When patients with a known alternative hereditary risk factor for venous thrombosis (factor V Leiden mutation or deficiency of antithrombin, protein C or protein S) were excluded, the G20210A variant was found to increase the risk for venous thrombosis by approximately 5-fold (odds ratio 5.4, 95% CI 1.16-25.0). This prothrombin gene sequence variation adds further to the list of recognized genetic risk factors for thrombophilia. PMID:9266933

  14. Cosolute effect on crystallization of two dinucleotide complexes of bovine seminal ribonuclease from concentrated salt solutions

    NASA Astrophysics Data System (ADS)

    Sica, Filomena; Adinolfi, Salvatore; Vitagliano, Luigi; Zagari, Adriana; Capasso, Sante; Mazzarella, Lelio

    1996-10-01

    Two complexes of bovine seminal ribonuclease with dinucleotides, uridylyl(2'-5')adenosine (UpA) and 2'-deoxycytidylyl(3'-5')-2'-deoxyadenosine (d(CpA)), were crystallized under unusual conditions involving a liquid-liquid phase separation. This phenomenon was induced by adding small aliquots of organic cosolutes to highly concentrated ammonium sulfate solutions. The liquid-liquid interface acts as a source of nucleation centers for growth of large crystals. Among the cosolutes tested in these salt-mediated crystallizations, 2-methyl-2,4-pentanediol was found to be the most efficient.

  15. nC60 deposition kinetics: the complex contribution of humic acid, ion concentration, and valence.

    PubMed

    McNew, Coy P; LeBoeuf, Eugene J

    2016-07-01

    The demonstrated toxicity coupled with inevitable environmental release of nC60 raise serious concerns about its environmental fate and transport, therefore it is crucial to understand how nC60 will interact with subsurface materials including attached phase soil and sediment organic matter (AP-SOM). This study investigated the attachment of nC60 onto a Harpeth humic acid (HHA) coated silica surface under various solution conditions using a quartz crystal microbalance with dissipation monitoring. The HHA coating greatly enhanced nC60 attachment at low ion concentrations while hindering attachment at high ion concentrations in the presence of both mono and divalent cations. At low ion concentrations, the HHA greatly reduced the surface potential of the silica, enhancing nC60 deposition through reduction in the electrostatic repulsion. At high ion concentrations however, the reduced surface potential became less important due to the near zero energy barrier to deposition and therefore non-DLVO forces dominated, induced by compaction of the HHA layer, and leading to hindered attachment. In this manner, observed contributions from the HHA layer were more complex than previously reported and by monitoring surface charge and calculated DLVO interaction energy alongside attachment experiments, this study advances the mechanistic understanding of the variable attachment contributions from the humic acid layer. PMID:27061365

  16. Molecular and genetic analysis of a compound heterozygote for dysprothrombinemia of prothrombin Tokushima and hypoprothrombinemia

    SciTech Connect

    Iwahana, Hiroyuki; Yoshimoto, Katsuhiko; Shigekiyo, Toshio; Shirakami, Akira; Saito, Shiro; Itakura, Mitsuo )

    1992-12-01

    The molecular and genetic basis of a compound heterozygote for dys- and hypoprothrombinemia was analyzed. Abnormal nucleotide sequences of the human prothrombin gene were screened by PCR-single-strand conformation polymorphism (PCR-SSCP) with endonuclease digestion and mutated primer-mediated PCR-RFLP. A single nucleotide substitution responsible for dysprothrombinemia of prothrombin Tokushima was detected, as were three polymorphisms. The mutation for hypoprothrombinemia was detected by PCR-single-strand conformation polymorphism (PCR-SSCP) with endonuclease digestion in exon 6, near MboII-RFLP and NcoI-RFLP. Sequencing of PCR-amplified genomic DNA revealed a single base insertion of thymine (T) at position 4177. The resulting frameshift mutation caused both an altered amino acid sequence from codon 114 and a premature termination codon (i.e., TGA) at codon 174 in exon 7. Because exon 7 encodes the kringle 2 domain preceding the thrombin sequence, this frameshift leads to the null prothrombin phenotype. The inheritance of the hypoprothrombinemia gene from the father to the proband was proved by PCR-SSCP with endonuclease digestion and mutated primer-mediated PCR-RFLP. 30 refs., 7 figs., 1 tab.

  17. Purification and characterization of a prothrombin-activating protease from Nephila clavata.

    PubMed

    Joo, Han-Seung; Park, Gun-Chun; Cho, Woo Ri; Tak, Eunsik; Paik, Seung R; Chang, Chung-Soon

    2002-03-01

    We report upon the purification and characterization of a novel prothrombin-activating enzyme from the body fluid (total homogenates of isolated digestive tract without eggs, spinnerets and silk glands) of the spider, Nephila clavata by a combination of acetone fractionation, ion exchange, and Soybean trypsin inhibitor-Sepharose chromatography. Analysis of the purified enzyme with SDS-PAGE and gel filtration revealed a single polypeptide chain with an apparent molecular weight of 24kDa. The proteolytic activity of the enzyme was stable up to 50 degrees C, however, it became unstable over 55 degrees C. The enzyme had an optimum pH of 8, and Ca(2+) was not required for the enzyme activity. According to inhibition profiles obtained with several serine protease inhibitors such as PMSF and benzamidine, the purified protease is a member of the serine proteases. Bz-Ile-Glu(gamma-OR)- Gly-Arg-pNA and Z-Arg-Gly-Arg-pNA which are known as substrates for factor Xa, were hydrolyzed favorably by the enzyme. And the Nephila protease could produce thrombin from prothrombin at nM range, and form the turbid ring using fibrinogen-agarose plate. The results obtained confirmed that the purified protease is a potent prothrombin-activating activity belonging to the family of serine protease. PMID:11711126

  18. Effects of vanadium complexes supplementation on V, Cu, Mn, K, Fe, Zn, and Ca concentration in STZ diabetic rats pancreas.

    PubMed

    Krośniak, Mirosław; Kowalska, Joanna; Francik, Renata; Gryboś, Ryszard; Kwiatek, Wojciech M

    2014-01-01

    The objective of the study was to assess the effects of Na[V(V)O(O2)2(2,2'-bpy)] x 8 H2O (complex 1), Na[V(V)O(O2)2(1,10'-phen)] x 5 H2O (complex 2), Na[V(V)O(O2)2(4,4'-Me-2,2'-bpy)] x 8 H2O (complex 3), [V(V)O(SO,)(1,10'-phen)] x 2 H2O, (complex 4), [V(IV)O(SO4)(2,2'-bpy)] x H2O (complex 5), where: 2,2'-bpy = 2,2'-bipyridine, 1.10'-phen = 1,10'-phenanthroline, 4,4'-Me-2,2'-bpy = 4,4'-dimethyl-2,2'-bipyridine and a small insulin injection on V, Cu, Mn, K, Fe, Zn, and Ca concentration in the STZ (streptozotocin) diabetic rats pancreas during a 5-week treatment with the tested complexes. In all groups of animals metal concentration in the pancreas was investigated by means of Proton Induced X-ray Emission (PIXE) method. Maximum concentration of vanadium was observed in the pancreas for complex 5 (1.69 +/- 0.09 mg/kg dry weight), lower for complex 3 (1.51 +/- 0.10 mg/kg dry weight), and the lowest for complex 1 (1.21 +/- 0.27 mg/kg dry weight) supplementation. The influence of vanadium administration on other metals' concentration in the rats' pancreas was also investigated. All vanadium-tested complexes showed an increase of zinc concentration in the examined pancreas in comparison to the diabetic animals not treated with vanadium. The results were the highest for complex 1 and the lowest for complex 5. The concentration of Fe, Cu, Mn, K and Ca in the pancreas is not evidently influenced by administration of the vanadium complexes. PMID:25275204

  19. Influence of the organic complex concentration on adsorption of herbicide in organic modified montmorillonite

    NASA Astrophysics Data System (ADS)

    Kaludjerovic, Lazar; Tomic, Zorica; Djurovic, Rada; Milosevic, Maja

    2016-04-01

    Pesticides are recognized as an important source of potential pollution to soil and water due to their mobility and degradation in soils. Results presented in this paper show impact of the organic complex concentration on the adsorption of herbicides (acetochlor) at the surface of the organic modified montmorillonite. In this work, natural montmorillonite from Bogovina, located near Boljevac municipality, was used for organic modification. Cation-exchange capacity of this montmorillonite was determined by extraction with ammonium acetate (86 mmol/100g of clay). Montmorillonite have been modified first with NaCl and than with two organic complexes, hexadecyltrimethylammonium bromide (HDTMA) and phenyltrimethylammonium chloride (PTMA). For both organic complexes, three saturation concentrations were selected for monitoring of the herbicide adsorption (43 mmol/100g of clay (0.5 CEC), 86 mmol/100g of clay (1 CEC) and 129 mmol/100g of clay (1.5 CEC)). Changes in the properties of the inorganic and organic bentonite have been examined using the X-ray powder diffraction (XRPD) and batch equilibrium method. Increase in basal spacing (d) of montmorillonites saturated with 1.5 CEC of organic cation indicate that sorption of PTMA and HDTMA can exceed the saturation of 1 CEC. Both organic montmorillonites have shown higher uptake of the herbicide, compared to the inorganic montmorillonite. Comparing the values Freundlich coefficients in batch equilibrium method, (presented in the form of log Kf and 1/n), it can be seen that the sorption decreases in the series: 0.5CEC> 1CEC> 1.5CEC> NaM, for both organic montmorillonites.

  20. Relationship between residual feed intake and lymphocyte mitochondrial complex protein concentration and ratio in crossbred steers.

    PubMed

    Davis, M P; Brooks, M A; Kerley, M S

    2016-04-01

    Rate of oxygen uptake by muscle mitochondria and respiratory chain protein concentrations differed between high- and low-residual feed intake (RFI) animals. The hypothesis of this research was that complex I (CI), II (CII), and III (CIII) mitochondria protein concentrations in lymphocyte (blood) mitochondria were related to the RFI phenotype of beef steers. Daily feed intake (ADFI) was individually recorded for 92 Hereford-crossbreed steers over 63 d using GrowSafe individual feed intake system. Predicted ADFI was calculated as the regression of ADFI on ADG and midtest BW. Difference between ADFI and predicted ADFI was RFI. Lymphocytes were isolated from low-RFI (-1.32 ± 0.11 kg/d; = 10) and high-RFI (1.34 ± 0.18 kg/d; = 8) steers. Immunocapture of CI, CII, and CIII proteins from the lymphocyte was done using MitoProfile CI, CII, and CIII immunocapture kits (MitoSciences Inc., Eugene, OR). Protein concentrations of CI, CII, and CIII and total protein were quantified using bicinchoninic acid colorimetric procedures. Low-RFI steers consumed 30% less ( = 0.0004) feed and had a 40% improvement ( < 0.0001) in feed efficiency compared with high-RFI steers with similar growth ( = 0.78) and weight measurements ( > 0.65). High- and low-RFI steers did not differ in CI ( = 0.22), CII ( = 0.69), and CIII ( = 0.59) protein concentrations. The protein concentration ratios for CI to CII ( = 0.03) were 20% higher and the ratios of CI to CIII ( = 0.01) were 30% higher, but the ratios of CII to CIII ( = 0.89) did not differ when comparing low-RFI steers with high-RFI steers. The similar magnitude difference in feed intake, feed efficiency measurements, and CI-to-CIII ratio between RFI phenotypes provides a plausible explanation for differences between the phenotypes. We also concluded that mitochondria isolated from lymphocytes could be used to study respiratory chain differences among differing RFI phenotypes. Further research is needed to determine if lymphocyte mitochondrial

  1. Concentration-dependent oligomerization of cross-linked complexes between ferredoxin and ferredoxin–NADP{sup +} reductase

    SciTech Connect

    Kimata-Ariga, Yoko Kubota-Kawai, Hisako; Lee, Young-Ho; Muraki, Norifumi; Ikegami, Takahisa; Kurisu, Genji; Hase, Toshiharu

    2013-05-17

    Highlights: •Cross-linked complexes of ferredoxin (Fd) and Fd–NADP{sup +} reductase form oligomers. •In the crystal structures, Fd- and FNR moieties swap across the molecules. •The complexes exhibit concentration-dependent oligomerization at sub-milimolar order. -- Abstract: Ferredoxin–NADP{sup +} reductase (FNR) forms a 1:1 complex with ferredoxin (Fd), and catalyzes the electron transfer between Fd and NADP{sup +}. In our previous study, we prepared a series of site-specifically cross-linked complexes of Fd and FNR, which showed diverse electron transfer properties. Here, we show that X-ray crystal structures of the two different Fd–FNR cross-linked complexes form oligomers by swapping Fd and FNR moieties across the molecules; one complex is a dimer from, and the other is a successive multimeric form. In order to verify whether these oligomeric structures are formed only in crystal, we investigated the possibility of the oligomerization of these complexes in solution. The mean values of the particle size of these cross-linked complexes were shown to increase with the rise of protein concentration at sub-milimolar order, whereas the size of dissociable wild-type Fd:FNR complex was unchanged as analyzed by dynamic light scattering measurement. The oligomerization products were detected by SDS–PAGE after chemical cross-linking of these complexes at the sub-milimolar concentrations. The extent and concentration-dependent profile of the oligomerizaion were differentiated between the two cross-linked complexes. These results show that these Fd–FNR cross-linked complexes exhibit concentration-dependent oligomerization, possibly through swapping of Fd and FNR moieties also in solution. These findings lead to the possibility that some native multi-domain proteins may present similar phenomenon in vivo.

  2. Calculation of 2,3,7,8-TCDD equivalent concentrations of complex environmental contaminant mixtures

    PubMed Central

    Eadon, George; Kaminsky, Laurence; Silkworth, Jay; Aldous, Kenneth; Hilker, David; O'Keefe, Patrick; Smith, Robert; Gierthy, John; Hawley, John; Kim, Nancy; DeCaprio, Anthony

    1986-01-01

    Sufficient toxicological data are now available to permit use of conventional risk assessment techniques to estimate the hazards associated with human exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). However, many real-world exposures involve complex mixtures of dibenzodioxins, dibenzofurans, and related compounds. Historical approaches to risk assessment on such mixtures have ranged from ignoring all compounds except 2,3,7,8-TCDD itself to assuming that all compounds have potencies equal to 2,3,7,8-TCDD. An alternative approach which uses existing literature data and analytical results to calculate the “2,3,7,8-TCDD equivalent” concentration of a mixture in order to “predict” its biological potency relative to 2,3,7,8-TCDD itself is advanced here. Previously reported in vivo acute and subchronic studies and some recently obtained analytical chemistry data are integrated here to clarify the utility of this important approach and to assess the uncertainties associated with its use. This predictive approach, and various conceptually similar ones, have now found wide applicability to the risk assessment process associated with exposure to complex mixtures of dioxins, dibenzofurans, and related compounds. PMID:3830107

  3. Calculation of 2,3,7,8-TCDD equivalent concentrations of complex environmental contaminant mixtures

    SciTech Connect

    Eadon, G.; Kaminsky, L.; Silkworth, J.; Aldous, K.; Hilker, D.; O'Keefe, P.; Smith, R.; Gierthy, J.; Hawley, J.; Kim, N.

    1986-12-01

    Sufficient toxicological data are now available to permit use of conventional risk assessment techniques to estimate the hazards associated with human exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). However, many real-world exposures involve complex mixtures of dibenzodioxins, dibenzofurans, and related compounds. Historical approaches to risk assessment on such mixtures have ranged from ignoring all compounds except 2,3,7,8-TCDD itself to assuming that all compounds have potencies equal to 2,3,7,8-TCDD. An alternative approach which uses existing literature data and analytical results to calculate the 2,3,7,8-TCDD equivalent concentration of a mixture in order to predict its biological potency relative to 2,3,7,8-TCDD itself is advanced here. Previously reported in vivo acute and subchronic studies and some recently obtained analytical chemistry data are integrated here to clarify the utility of this important approach and to assess the uncertainties associated with its use. This predictive approach, and various conceptually similar ones, have now found wide applicability to the risk assessment process associated with exposure to complex mixtures of dioxins, dibenzofurans, and related compounds.

  4. Concentration of PGE in the Earth's Crust with Special Reference to the Bushveld Complex

    NASA Astrophysics Data System (ADS)

    Naldrett, Tony; Kinnaird, Judith; Wilson, Allan; Chunnett, Gordon

    The Earth's mantle is the principal reservoir from which platinum-group element (PGE) concentrations in the crust are derived. The transfer of the PGE is accomplished by two main methods, first the development of mantle partial melts and their intrusion into the crust, and second the emplacement of mantle slabs in the subduction/collision zones. The first mechanism is far more important than the second. Once in the crust, a number of mechanisms serve to concentrate the PGE sufficiently so that they can be exploited economically as the principal product, rather than as a by-product. These include (i) the development of an Ni-Cu sulfide liquid in a mafic intrusion, the concentration of this liquid, followed by cooling and fractional crystallization that results in a residual sulfide liquid highly enriched in Cu, Pt, and Pd; (ii) the formation of layers of very high-PGE tenor sulfides at specific horizons within a layered intrusion, either with or without associated chromitite; (iii) the emplacement of magma carrying PGE-rich sulfide along the margins of layered intrusions; (iv) the delayed separation of immiscible sulfides until the late stages of the differentiation of a layered intrusion; (v) chromite crystallization without the development of sulfide immiscibility; (vi) hydrothermal redistribution and concentration of PGE from zones of low grade disseminated sulfide; (vii) secondary concentration of PGE along with chromite during recrystallization of Ural-Alaskan intrusions and the subsequent development of placer deposits during the weathering of these bodies; and (viii) the concentration of Pt during the formation of black shale deposits. The Bushveld Igneous Complex of South Africa hosts 75% of the world's resources of Pt, 54% of Pd resources, and 82% of Rh resources, and contains examples of mineralization formed by processes (ii), (iii), (iv), (v), and (vi) listed above. Of these, process (ii) accounts for 90% of the current economic reserves and resources

  5. Reduction of arsenic content in a complex galena concentrate by Acidithiobacillus ferrooxidans

    PubMed Central

    Makita, Mario; Esperón, Margarita; Pereyra, Benito; López, Alejandro; Orrantia, Erasmo

    2004-01-01

    Background Bioleaching is a process that has been used in the past in mineral pretreatment of refractory sulfides, mainly in the gold, copper and uranium benefit. This technology has been proved to be cheaper, more efficient and environmentally friendly than roasting and high pressure moisture heating processes. So far the most studied microorganism in bioleaching is Acidithiobacillus ferrooxidans. There are a few studies about the benefit of metals of low value through bioleaching. From all of these, there are almost no studies dealing with complex minerals containing arsenopyrite (FeAsS). Reduction and/or elimination of arsenic in these ores increase their value and allows the exploitation of a vast variety of minerals that today are being underexploited. Results Arsenopyrite was totally oxidized. The sum of arsenic remaining in solution and removed by sampling represents from 22 to 33% in weight (yield) of the original content in the mineral. The rest of the biooxidized arsenic form amorphous compounds that precipitate. Galena (PbS) was totally oxidized too, anglesite (PbSO4) formed is virtually insoluble and remains in the solids. The influence of seven factors in a batch process was studied. The maximum rate of arsenic dissolution in the concentrate was found using the following levels of factors: small surface area of particle exposure, low pulp density, injecting air and adding 9 K medium to the system. It was also found that ferric chloride and carbon dioxide decreased the arsenic dissolution rate. Bioleaching kinetic data of arsenic solubilization were used to estimate the dilution rate for a continuous culture. Calculated dilution rates were relatively small (0.088–0.103 day-1). Conclusion Proper conditions of solubilization of arsenic during bioleaching are key features to improve the percentage (22 to 33% in weight) of arsenic removal. Further studies are needed to determine other factors that influence specifically the solubilization of arsenic in

  6. Genetic diminution of circulating prothrombin ameliorates multiorgan pathologies in sickle cell disease mice.

    PubMed

    Arumugam, Paritha I; Mullins, Eric S; Shanmukhappa, Shiva Kumar; Monia, Brett P; Loberg, Anastacia; Shaw, Maureen A; Rizvi, Tilat; Wansapura, Janaka; Degen, Jay L; Malik, Punam

    2015-10-01

    Sickle cell disease (SCD) results in vascular occlusions, chronic hemolytic anemia, and cumulative organ damage. A conspicuous feature of SCD is chronic inflammation and coagulation system activation. Thrombin (factor IIa [FIIa]) is both a central protease in hemostasis and a key modifier of inflammatory processes. To explore the hypothesis that reduced prothrombin (factor II [FII]) levels in SCD will limit vaso-occlusion, vasculopathy, and inflammation, we used 2 strategies to suppress FII in SCD mice. Weekly administration of FII antisense oligonucleotide "gapmer" to Berkeley SCD mice to selectively reduce circulating FII levels to ∼10% of normal for 15 weeks significantly diminished early mortality. More comprehensive, long-term comparative studies were done using mice with genetic diminution of circulating FII. Here, cohorts of FII(lox/-) mice (constitutively carrying ∼10% normal FII) and FII(WT) mice were tracked in parallel for a year following the imposition of SCD via hematopoietic stem cell transplantation. This genetically imposed suppression of FII levels resulted in an impressive reduction in inflammation (reduction in leukocytosis, thrombocytosis, and circulating interleukin-6 levels), reduced endothelial cell dysfunction (reduced endothelial activation and circulating soluble vascular cell adhesion molecule), and a significant improvement in SCD-associated end-organ damage (nephropathy, pulmonary hypertension, pulmonary inflammation, liver function, inflammatory infiltration, and microinfarctions). Notably, all of these benefits were achieved with a relatively modest 1.25-fold increase in prothrombin times, and in the absence of hemorrhagic complications. Taken together, these data establish that prothrombin is a powerful modifier of SCD-induced end-organ damage, and present a novel therapeutic target to ameliorate SCD pathologies. PMID:26286849

  7. Genetic diminution of circulating prothrombin ameliorates multiorgan pathologies in sickle cell disease mice

    PubMed Central

    Arumugam, Paritha I.; Mullins, Eric S.; Shanmukhappa, Shiva Kumar; Monia, Brett P.; Loberg, Anastacia; Shaw, Maureen A.; Rizvi, Tilat; Wansapura, Janaka; Degen, Jay L.

    2015-01-01

    Sickle cell disease (SCD) results in vascular occlusions, chronic hemolytic anemia, and cumulative organ damage. A conspicuous feature of SCD is chronic inflammation and coagulation system activation. Thrombin (factor IIa [FIIa]) is both a central protease in hemostasis and a key modifier of inflammatory processes. To explore the hypothesis that reduced prothrombin (factor II [FII]) levels in SCD will limit vaso-occlusion, vasculopathy, and inflammation, we used 2 strategies to suppress FII in SCD mice. Weekly administration of FII antisense oligonucleotide “gapmer” to Berkeley SCD mice to selectively reduce circulating FII levels to ∼10% of normal for 15 weeks significantly diminished early mortality. More comprehensive, long-term comparative studies were done using mice with genetic diminution of circulating FII. Here, cohorts of FIIlox/− mice (constitutively carrying ∼10% normal FII) and FIIWT mice were tracked in parallel for a year following the imposition of SCD via hematopoietic stem cell transplantation. This genetically imposed suppression of FII levels resulted in an impressive reduction in inflammation (reduction in leukocytosis, thrombocytosis, and circulating interleukin-6 levels), reduced endothelial cell dysfunction (reduced endothelial activation and circulating soluble vascular cell adhesion molecule), and a significant improvement in SCD-associated end-organ damage (nephropathy, pulmonary hypertension, pulmonary inflammation, liver function, inflammatory infiltration, and microinfarctions). Notably, all of these benefits were achieved with a relatively modest 1.25-fold increase in prothrombin times, and in the absence of hemorrhagic complications. Taken together, these data establish that prothrombin is a powerful modifier of SCD-induced end-organ damage, and present a novel therapeutic target to ameliorate SCD pathologies. PMID:26286849

  8. A Study of Anti Beta-2 Glycoprotein I and Anti-Prothrombin Antibodies in Patients with Unexplained Recurrent Pregnancy Losses.

    PubMed

    Singh, Angad; Nangia, Anita; Sharma, Sunita; Puri, Manju

    2016-06-01

    To compare the levels of IgG and IgM anti beta-2 glycoprotein I antibodies and IgG and IgM anti prothrombin antibodies among women with unexplained recurrent pregnancy losses and women with at least 2 live issues. To compare the prevalence of newer anti beta-2 glycoprotein I & anti prothrombin antibodies with conventional Lupus anticoagulant & anticardiolipin antibodies. 50 women with recurrent pregnancy losses & 50 matched controls were evaluated for the presence of: Lupus anticoagulant-screened by LA sensitive aPTT& DRVV and confirmatory Staclot Assay. ELISA kits were used for detecting IgG & IgM anticardiolipin, anti beta-2 glycoprotein I & anti prothrombin antibodies. 11/50 (22 %) women in study group and none in control group had circulating antiphospholipid antibodies. 2 cases (4 %) had lupus anticoagulant. 1 case (2 %) had anticardiolipin antibody & 6 cases (12 %) were positive for anti beta-2 Glycoprotein I antibody (p value = 0.027). 3 cases (6 %) had anti prothrombin antibody. All were mutually exclusive except for one. Women with recurrent pregnancy losses should be tested for anti beta-2 Glycoprotein I antibodies & anti prothrombin antibodies in addition to conventional lupus anticoagulant and anticardiolipin antibodies. This approach can decrease the incidence of SNAP (seronegative antiphospholipid syndrome) cases while establishing the true prevalence of antiphospholipid syndrome. PMID:27065583

  9. The Aqueous Thermodynamics and Complexation Reactions of Anionic Silica and Uranium Species to High Concentration.

    SciTech Connect

    Felmy, Andrew R.; Choppin, Gregory R.

    2005-06-01

    Highly basic tank wastes contain several important radionuclides, including 90Sr, 99Tc, and 60Co, as well as actinide elements (i.e., isotopes of U, Pu, and Am). These highly basic tank wastes are known to have leaked into the vadose zone at the Hanford Site. In particular, wastes from the bismuth phosphate process contained very high concentrations of U as well as carbonate, phosphate, nitrate, and other components (AEC 1951) and these solutions have leaked into the subsurface at the Hanford site. The tanks containing the bismuth phosphate wastes were frequently saturated with respect to the solid phases of these components [e.g., NaUO2PO4(c) and Na4UO2(CO3)3(c)]. These solids were referred to as ''hard sludge'' (Na4UO2(CO3)3(c)) and ?soft sludge? [NaUO2PO4(c)] because of their different crystal forms. The preliminary studies of the solubility of these solids in tank wastes (AEC 1951) indicate that aqueous U carbonate complexes dominate the solution chemistry of uranium even when the equilibrium solid was NaUO2PO4. Thus there was a need to develop an accurate thermodynamic model for the solubility of potentially important U(VI) phosphate and carbonate phases as well as to develop a model for the uranium carbonate complexes valid to high ionic strength. In this project we are examining the solubility of these important solid phases as well as the aqueous thermodynamics of U(VI) species under strongly basic conditions. Also included is a description of our efforts to include these thermodynamic models in the reactive transport and residual leaching models being used at the Hanford site and elsewhere.

  10. Molecular dynamics simulations of polyelectrolyte-polyampholyte complexes. Effect of solvent quality and salt concentration.

    PubMed

    Jeon, Junhwan; Dobrynin, Andrey V

    2006-12-01

    variations in the excess of concentration of monomers belonging to polyampholyte and polyelectrolyte chains throughout the core radius. These structures appear as a result of optimization of the net electrostatic energy of the complex and short-range attractive interactions between monomers of the polyelectrolyte chain. PMID:17134228

  11. A fluorescence anisotropy method for measuring protein concentration in complex cell culture media.

    PubMed

    Groza, Radu Constantin; Calvet, Amandine; Ryder, Alan G

    2014-04-22

    The rapid, quantitative analysis of the complex cell culture media used in biopharmaceutical manufacturing is of critical importance. Requirements for cell culture media composition profiling, or changes in specific analyte concentrations (e.g. amino acids in the media or product protein in the bioprocess broth) often necessitate the use of complicated analytical methods and extensive sample handling. Rapid spectroscopic methods like multi-dimensional fluorescence (MDF) spectroscopy have been successfully applied for the routine determination of compositional changes in cell culture media and bioprocess broths. Quantifying macromolecules in cell culture media is a specific challenge as there is a need to implement measurements rapidly on the prepared media. However, the use of standard fluorescence spectroscopy is complicated by the emission overlap from many media components. Here, we demonstrate how combining anisotropy measurements with standard total synchronous fluorescence spectroscopy (TSFS) provides a rapid, accurate quantitation method for cell culture media. Anisotropy provides emission resolution between large and small fluorophores while TSFS provides a robust measurement space. Model cell culture media was prepared using yeastolate (2.5 mg mL(-1)) spiked with bovine serum albumin (0 to 5 mg mL(-1)). Using this method, protein emission is clearly discriminated from background yeastolate emission, allowing for accurate bovine serum albumin (BSA) quantification over a 0.1 to 4.0 mg mL(-1) range with a limit of detection (LOD) of 13.8 μg mL(-1). PMID:24703214

  12. Prothrombin activator-like toxin appears to mediate cardiovascular collapse following envenoming by Pseudonaja textilis.

    PubMed

    Chaisakul, Janeyuth; Isbister, Geoffrey K; O'Leary, Margaret A; Parkington, Helena C; Smith, A Ian; Hodgson, Wayne C; Kuruppu, Sanjaya

    2015-08-01

    Brown snake (Pseudonaja spp.)-induced early cardiovascular collapse is a life-threatening medical emergency in Australia. We have previously shown that this effect can be mimicked in animals and is mediated via the release of endogenous mediators. In the present study, we aimed to purify and characterize the component in Pseudonaja textilis venom which induces cardiovascular collapse following envenoming. The component (fraction 3) was isolated using a combination of techniques including hydroxyapatite and reverse phase chromatography. Fraction 3 (10 or 20 μg/kg, i.v.) produced a rapid decrease in mean arterial pressure (MAP) followed by cardiovascular collapse. Fraction 3-induced early collapse was abolished by prior administration of smaller priming doses of fraction 3 (i.e. 2 and 5 μg/kg, i.v.) or heparin (300 units/kg, i.v.). P. textilis whole venom (1 and 3 μg/ml), but not fraction 3 (1 or 3 μg/ml), induced endothelium-dependent relaxation in isolated rat mesenteric arteries. SDS-PAGE gel indicated the presence of 9-10 protein bands of fraction 3. Using proteomic based analysis some protein bands of fraction 3 were identified as subunits of venom prothrombin activator, pseutarin C of P. textilis venom. Our results conclude that prothrombin activator-like toxin is likely to be a contributor to the rapid collapse induced by P. textilis venom. PMID:25959508

  13. Lonomia obliqua caterpillar spicules trigger human blood coagulation via activation of factor X and prothrombin.

    PubMed

    Donato, J L; Moreno, R A; Hyslop, S; Duarte, A; Antunes, E; Le Bonniec, B F; Rendu, F; de Nucci, G

    1998-03-01

    In southern Brazil, envenomation by larvae of the moth Lonomia obliqua (Walker) may result in blood clotting factor depletion, leading to disseminated intravascular coagulation with subsequent haemorrhage and acute renal failure which may prove fatal. We have examined the effect of a crude extract of spicules from these caterpillars on in vitro hemostasis. The extract alone did not aggregate platelets and had no detectable effect on purified fibrinogen, suggesting that extract induces clot formation by triggering activation of the clotting cascade. In agreement with the presence of thrombin-mediated activity, hirudin prevented clot formation. The extract was found to activate both prothrombin and factor X, suggesting that the depletion of blood clotting factors results from the steady activation of factor X and prothrombin. Heating and diisopropylfluorophosphate abolished the procoagulant activity of the extract, indicating that the active component involved is a protein that may belong to the serine protease family of enzymes. The ability of hirudin to inhibit this coagulant activity suggests that this inhibitor could be beneficial in the treatment of patients envenomed by L. obliqua caterpillars. PMID:9531036

  14. Chemical Swarming: Depending on Concentration, an Amphiphilic Ruthenium Polypyridyl Complex Induces Cell Death via Two Different Mechanisms.

    PubMed

    Siewert, Bianka; van Rixel, Vincent H S; van Rooden, Eva J; Hopkins, Samantha L; Moester, Miriam J B; Ariese, Freek; Siegler, Maxime A; Bonnet, Sylvestre

    2016-07-25

    The crystal structure and in vitro cytotoxicity of the amphiphilic ruthenium complex [3](PF6 )2 are reported. Complex [3](PF6 )2 contains a Ru-S bond that is stable in the dark in cell-growing medium, but is photosensitive. Upon blue-light irradiation, complex [3](PF6 )2 releases the cholesterol-thioether ligand 2 and an aqua ruthenium complex [1](PF6 )2 . Although ligand 2 and complex [1](PF6 )2 are by themselves not cytotoxic, complex [3](PF6 )2 was unexpectedly found to be as cytotoxic as cisplatin in the dark, that is, with micromolar effective concentrations (EC50 ), against six human cancer cell lines (A375, A431, A549, MCF-7, MDA-MB-231, and U87MG). Blue-light irradiation (λ=450 nm, 6.3 J cm(-2) ) had little influence on the cytotoxicity of [3](PF6 )2 after 6 h of incubation time, but it increased the cytotoxicity of the complex by a factor 2 after longer (24 h) incubation. Exploring the unexpected biological activity of [3](PF6 )2 in the dark elucidated an as-yet unknown bifaceted mode of action that depended on concentration, and thus, on the aggregation state of the compound. At low concentration, it acts as a monomer, inserts into the membrane, and can deliver [1](2+) inside the cell upon blue-light activation. At higher concentrations (>3-5 μm), complex [3](PF6 )2 forms supramolecular aggregates that induce non-apoptotic cell death by permeabilizing cell membranes and extracting lipids and membrane proteins. PMID:27373895

  15. Coagulation Factor Concentrates Fail to Restore Alterations in Fibrin Formation Caused by Rivaroxaban or Dabigatran in Studies With Flowing Blood From Treated Healthy Volunteers.

    PubMed

    Arellano-Rodrigo, Eduardo; Lopez-Vilchez, Irene; Galan, Ana M; Molina, Patricia; Reverter, Joan Carles; Carné, Xavier; Villalta, Jaume; Tassies, Dolors; Lozano, Miguel; Díaz-Ricart, Maribel; Escolar, Gines

    2015-10-01

    We evaluated the hemostatic alterations in blood from healthy individuals treated for 5 days with direct oral anticoagulants (DOACs) rivaroxaban (20 mg/d) or dabigatran (150 mg/12 h) in a single-blind clinical trial with crossover assignment (NCT01478282). We assessed the potential of prothrombin complex concentrates, activated prothrombin complex concentrates, or recombinant activated factor VII, when added ex vivo, to reverse the alterations caused by these DOACs. Blood was drawn at maximum plasma concentration after the last dose of each DOAC, and modifications in coagulation biomarkers were evaluated using a series of tests performed under steady conditions including routine coagulation, thrombin generation, and thromboelastometry assays. Additional studies in standardized flow devices were applied to evaluate alterations on platelet deposition and fibrin formation on damaged vascular surfaces exposed to flowing blood. Both DOACs caused important modifications of all coagulation biomarkers and significantly reduced fibrin formation in flow studies. Alterations in biomarkers observed in steady laboratory tests were normalized and occasionally overcompensated by procoagulant strategies. In contrast, reductions in fibrin formation observed in studies with flowing blood were improved, although never completely restored to baseline levels. Effects of dabigatran in flow studies appeared more resistant to reversal strategies than those of rivaroxaban. Inconsistencies between results of coagulation studies in steady or flowing assays not only raise concerns about the adequacy of the earlier tests to predict the restoration of the coagulopathy induced by DOACs but also suggest limitations of nonspecific procoagulant strategies to control severe coagulopathy in patients inadvertently overexposed these agents. PMID:26364029

  16. Association of C677T MTHFR and G20210A FII prothrombin polymorphisms with susceptibility to myocardial infarction

    PubMed Central

    Hmimech, Wiam; Idrissi, Hind Hassani; Diakite, Brehima; Baghdadi, Dalila; Korchi, Farah; Habbal, Rachida; Nadifi, Sellama

    2016-01-01

    Myocardial infarction (MI) is a common complex pathology, localized in the main leading causes of mortality worldwide. It is the result of the interaction of genetic and environmental factors. The aim of the present study was to investigate the potential association of C677T 5,10-methylenetetrahydrofolate reductase (MTHFR) (rs1801133) and G20210A factor II prothrombin (FII) (rs1799963) polymorphisms with the susceptibility of MI. Following extraction by the standard salting-out procedure, DNA samples of 100 MI patients and 182 apparently healthy controls were genotyped by polymerase chain reaction-restriction fragment length polymorphism using HinfI and HindIII restriction enzymes, respectively. The results show a significant association of the G20210T FII polymorphism with the MI risk. The frequencies of the heterozygote genotype GA, homozygous mutated AA and the G20210A allele was higher among patients compared to controls (GA: 59 vs. 5.5%, P<0.001; AA: 10 vs. 0%, P=0.003; and 20210A: 39.5 vs. 2.7%, P<0.003), suggesting that this polymorphism may be a potential genetic marker for MI. No significant association was observed between the C677T MTHFR and MI occurrence, and there was more heterozygote CT in the patient group compared to the controls. As a multifactorial disease, the development of MI may be the result of numerous factors that influence synergistically its occurrence. Thus, further studies are merited to try to better assess these associations (gene-gene and gene-environment interactions). PMID:27588178

  17. Association of corticosteroids and factor V, prothrombin, and MTHFR gene mutations with avascular osteonecrosis in renal allograft recipients.

    PubMed

    Celik, A; Tekis, D; Saglam, F; Tunali, S; Kabakci, N; Ozaksoy, D; Manisali, M; Ozcan, M A; Meral, M; Gülay, H; Camsari, T

    2006-03-01

    The mechanism of posttransplantation avascular osteonecrosis (AVN) is controversial. Besides an increased bone marrow pressure due to reduced blood supply, enhanced coagulation has been considered. We investigated the associations of factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations as well as cumulative corticosteroid doses with AVN in renal allograft recipients. The records of 39 volunteer patients and 11 patients in whom osteonecrosis was previously identified were reviewed for cumulative corticosteroid dosages during the first year. All patients were screened for factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations by direct sequencing of genomic DNA. The cumulative corticosteroid dosages at 3, 6, and 12 months in the osteonecrotic group (5033.5 +/- 1565.3, 7164.9 +/- 2063.1, 8835.1 +/- 2216.8 mg) were significantly higher than in the control group (3629 +/- 1504.1, 4784.5 +/- 1568.7, 6322.4 +/- 1686.6 mg; P = .013, P = .001, P = .001, respectively). No significant difference in factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations was observed between the osteonecrotic and control groups (P > .05). In conclusion, an association between the first year (3, 6, and 12 month) cumulative corticosteroid dosages and AVN was demonstrated in renal transplant recipients. However, no correlation was determined between factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations and osteonecrosis. PMID:16549163

  18. Des-γ-carboxy prothrombin (DCP) as a potential autologous growth factor for the development of hepatocellular carcinoma.

    PubMed

    Zhang, Yu-Sheng; Chu, Jia-Hui; Cui, Shu-Xiang; Song, Zhi-Yu; Qu, Xian-Jun

    2014-01-01

    Des-γ-carboxy prothrombin (DCP) is a prothrombin precursor produced in hepatocellular carcinoma (HCC). Because of deficiency of vitamin K or γ-glutamyl carboxylase in HCC cells, the 10 glutamic acid (Glu) residues in prothrombin precursor did not completely carboxylate to γ-carboxylated glutamic acid (Gla) residues, leaving some Glu residues remained in N-terminal domain. These prothrombin precursors with Glu residues are called DCPs. DCP displays insufficient coagulation activity. Since Liebman reported an elevated plasma DCP in patients with HCC, DCP has been used in the diagnosis of HCC. Recently, its biological malignant potential has been specified to describe DCP as an autologous growth factor to stimulate HCC growth and a paracrine factor to integrate HCC with vascular endothelial cells. DCP was found to stimulate HCC growth through activation of the DCP-Met-JAK1-STAT3 signaling pathway. DCP might increase HCC invasion and metastasis through activation of matrix metalloproteinase (MMPs) and the ERK1/2 MAPK signaling pathway. DCP has also been found to play a crucial role in the formation of angiogenesis. DCP could increase the angiogenic factors released from HCC and vascular endothelial cells. These effects of DCP in angiogenesis might be related to activation of the DCP-KDR-PLC-γ-MAPK signaling pathway. In this article, we summarized recent studies on DCP in biological roles related to cancer progression and angiogenesis in HCC. PMID:25200250

  19. Effectiveness of holographic optical element module sensor in measuring blood prothrombin time

    NASA Astrophysics Data System (ADS)

    Lin, Yu-Cheng; Yen, Shih-Chieh; Cheng, Stone; Huang, Tony

    2014-07-01

    A small-form-factor holographic optical element (HOE) module, which was mounted on a dual-stage seesaw actuator, was utilized to evaluate blood coagulation in real time. The method involved assessing the decrease in transmitted light of the blood sample surface when the clotting is formed. The prothrombin time (PT) was measured by illumining and focusing a 635 nm laser beam onto the sample. As the fibrinogen turned into non-solute fibrin, the transmitted efficiency and total intensity of the reflected light from the reflector changed. A low-pass filter suppressed the noise in the coagulation-related transient response to yield accurate signals. Finally, the PT measurements were compared to those made classically using other optical sensors.

  20. Changes in phylloquinone epoxidase activity related to prothrombin synthesis and microsomal clotting activity in the rat

    PubMed Central

    Willingham, Allan K.; Matschiner, John T.

    1974-01-01

    The oxidation of phylloquinone to the 2,3-epoxide (by phylloquinone epoxidase) was studied in liver from control and warfarin-resistant rats. The reaction requires microsomal fraction, soluble protein, a heat-stable soluble factor and O2. It is not inhibited by CO or CN−. Epoxidase activity was stimulated if plasma prothrombin was lowered either by anticoagulants or the absence of vitamin K. The activity of the enzyme rapidly returned to normal values after the administration of vitamin K to hypoprothrombinaemic rats. These differences in the activity of the enzyme occur in the microsomal fraction and not the cytosol. A thrombin-generating polypeptide that accumulates in microsomal fraction of hypothrombinaemic rats correlated directly with epoxidase activity. These data support the view that enzymic interconversion of phylloquinone and its 2,3-epoxide participates in the biological activity of vitamin K. PMID:4155625

  1. Prothrombin Kringle-2: A Potential Inflammatory Pathogen in the Parkinsonian Dopaminergic System

    PubMed Central

    Leem, Eunju; Jeong, Kyoung Hoon; Won, So-Yoon

    2016-01-01

    Although accumulating evidence suggests that microglia-mediated neuroinflammation may be crucial for the initiation and progression of Parkinson's disease (PD), and that the control of neuroinflammation may be a useful strategy for preventing the degeneration of nigrostriatal dopaminergic (DA) projections in the adult brain, it is still unclear what kinds of endogenous biomolecules initiate microglial activation, consequently resulting in neurodegeneration. Recently, we reported that the increase in the levels of prothrombin kringle-2 (pKr-2), which is a domain of prothrombin that is generated by active thrombin, can lead to disruption of the nigrostriatal DA projection. This disruption is mediated by neurotoxic inflammatory events via the induction of microglial Toll-like receptor 4 (TLR4) in vivo , thereby resulting in less neurotoxicity in TLR4-deficient mice. Moreover, inhibition of microglial activation following minocycline treatment, which has anti-inflammatory activity, protects DA neurons from pKr-2-induced neurotoxicity in the substantia nigra (SN) in vivo. We also found that the levels of pKr-2 and microglial TLR4 were significantly increased in the SN of PD patients compared to those of age-matched controls. These observations suggest that there may be a correlation between pKr-2 and microglial TLR4 in the initiation and progression of PD, and that inhibition of pKr-2-induced microglial activation may be protective against the degeneration of the nigrostriatal DA system in vivo. To describe the significance of pKr-2 overexpression, which may have a role in the pathogenesis of PD, we have reviewed the mechanisms of pKr-2-induced microglial activation, which results in neurodegeneration in the SN of the adult brain. PMID:27574481

  2. Prothrombin Kringle-2: A Potential Inflammatory Pathogen in the Parkinsonian Dopaminergic System.

    PubMed

    Leem, Eunju; Jeong, Kyoung Hoon; Won, So-Yoon; Shin, Won-Ho; Kim, Sang Ryong

    2016-08-01

    Although accumulating evidence suggests that microglia-mediated neuroinflammation may be crucial for the initiation and progression of Parkinson's disease (PD), and that the control of neuroinflammation may be a useful strategy for preventing the degeneration of nigrostriatal dopaminergic (DA) projections in the adult brain, it is still unclear what kinds of endogenous biomolecules initiate microglial activation, consequently resulting in neurodegeneration. Recently, we reported that the increase in the levels of prothrombin kringle-2 (pKr-2), which is a domain of prothrombin that is generated by active thrombin, can lead to disruption of the nigrostriatal DA projection. This disruption is mediated by neurotoxic inflammatory events via the induction of microglial Toll-like receptor 4 (TLR4) in vivo , thereby resulting in less neurotoxicity in TLR4-deficient mice. Moreover, inhibition of microglial activation following minocycline treatment, which has anti-inflammatory activity, protects DA neurons from pKr-2-induced neurotoxicity in the substantia nigra (SN) in vivo. We also found that the levels of pKr-2 and microglial TLR4 were significantly increased in the SN of PD patients compared to those of age-matched controls. These observations suggest that there may be a correlation between pKr-2 and microglial TLR4 in the initiation and progression of PD, and that inhibition of pKr-2-induced microglial activation may be protective against the degeneration of the nigrostriatal DA system in vivo. To describe the significance of pKr-2 overexpression, which may have a role in the pathogenesis of PD, we have reviewed the mechanisms of pKr-2-induced microglial activation, which results in neurodegeneration in the SN of the adult brain. PMID:27574481

  3. Phosphatidylserine-containing membranes alter the thermal stability of prothrombin's catalytic domain: a differential scanning calorimetric study.

    PubMed

    Lentz, B R; Zhou, C M; Wu, J R

    1994-05-10

    Denaturation profiles of bovine prothrombin and its isolated fragments were examined in the presence of Na2EDTA, 5 mM CaCl2, and CaCl2 plus membranes containing 1-palmitoyl-2-oleoyl-3-sn-phosphatidylcholine (POPC) in combination with bovine brain phosphatidylserine (PS). We have shown previously [Lentz, B. R., Wu, J. R., Sorrentino, A. M., & Carleton, J. A. (1991) Biophys. J. 60, 70] that binding to PS/POPC (25/75) large unilamellar vesicles resulted in an enthalpy loss in the main endotherm of prothrombin denaturation (Tm approximately 57-58 degrees C) and a comparable enthalpy gain in a minor endotherm (Tm approximately 59 degrees C) accompanying an upward shift in peak temperature (Tm approximately 73 degrees C). This minor endotherm was also responsive to Ca2+ binding and, in the absence of PS/POPC membranes, corresponded to melting of the N-terminal, Ca2+ and membrane binding domain (fragment 1). Peak deconvolution analysis of the prothrombin denaturation profile and extensive studies of the denaturation of isolated prothrombin domains in the presence and absence of PS/POPC vesicles suggested that membrane binding induced changes in the C-terminal catalytic domain of prothrombin (prethrombin 2) and in a domain that links fragment 1 with the catalytic domain (fragment 2). Specifically, the results have confirmed that the fragment 2 domain interacts with the stabilizes the prethrombin 2 domain and also have shown that fragment 2 interacts directly with the membrane. In addition, the results have demonstrated a heretofore unrecognized interaction between the catalytic and membrane binding domains. This interaction can account for another portion of the denaturation enthalpy that appears at high temperatures in the presence of membranes.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8180168

  4. Effects of vanadium complexes supplementation on V, Fe, Cu, Zn, Mn, Ca and K concentration in STZ diabetic rat's spleen.

    PubMed

    Krośniak, Mirosław; Francik, Renata; Kowalska, Joanna; Gryboś, Ryszard; Blusz, Magdalena; Kwiatek, Wojciech M

    2013-01-01

    Abstract: The objective of the study was to assess the effects of five vanadium organic complexes administered with small insulin injection, on V, Fe, Cu, Zn, Mn, Ca and K concentration in STZ (streptozotocin) diabetic rats tissues during a 5-week treatment with the tested complexes. In all groups of animals, metal concentration in a dry spleen samples was investigated by the proton induced X-ray emission (PIXE) method. Obviously, vanadium tissue concentration was higher in vanadium-treated rats. Concentration of vanadium in the spleen was x = 21.3 microg/g of dry sample. Vanadium administration influenced other metals concentration of rats tissues. The most pronounced influence of vanadium was observed on iron concentration in the spleen. All results were calculated for correlation between different groups of animals. Present study showed small interferences between trace element changes in diabetic, or non diabetic rats after vanadium treatment. Measured elements, especially zinc, manganese and copper, are co-factors of enzymes and their content changes can influence on organism homeostasis in diabetes treatment. Understanding and recognizing these relationship may permit better diabetes treatment in the future. PMID:23610961

  5. ESTIMATION OF POLLUTANT CONCENTRATION FROM SOURCES NEAR COMPLEX TERRAIN IN NEUTRAL FLOW

    EPA Science Inventory

    A wind tunnel study was conducted to determine maximum ground-level concentrations for a variety of source positions (locations and heights) both upstream and downstream of two model hills, an axisymmetric hill and a two-dimensional ridge, immersed in a simulated neutral atmosphe...

  6. Molecular Dynamics Simulations of Polyelectrolyte-Polyampholyte Complexes. Effect of Solvent Quality and Salt Concentration.

    NASA Astrophysics Data System (ADS)

    Jeon, Junhwan; Dobrynin, Andrey

    2006-03-01

    Using molecular dynamics simulations we have studied complexation in polyelectrolyte-polyampholyte mixtures in poor solvent conditions for the polyelectrolyte backbone. In a poor solvent a polyelectrolyte form a necklace-like structure. Upon forming a complex with both random and diblock polyampholytes a polyelectrolyte chain changes its necklace conformation by forming one huge bead. The collapse of the polyelectrolyte chain occurs due to neutralization of the polyelectrolyte charge by polyampholytes. In the case of the random polyampholyte the more positively charged sections of the chain adsorb on the surface of the globular bead while more negatively charged chain sections form loops surrounding the collapsed core of the aggregate. In the case of diblock polyampholyte the positively charged block and a part of the negatively charged block wraps around the collapsed polyelectrolyte with a substantial section of the negatively charged block sticking out from the collapsed center of the aggregate. These structures appear as a result of optimization of the net electrostatic energy of the complex and short-range attractive interactions between monomers of the polyelectrolyte chain.

  7. Evidence for the complex relationship between free amino acid and sugar concentrations and acrylamide-forming potential in potato

    PubMed Central

    Muttucumaru, N; Powers, SJ; Elmore, JS; Briddon, A; Mottram, DS; Halford, NG

    2014-01-01

    Free amino acids and reducing sugars participate in the Maillard reaction during high-temperature cooking and processing. This results not only in the formation of colour, aroma and flavour compounds, but also undesirable contaminants, including acrylamide, which forms when the amino acid that participates in the reaction is asparagine. In this study, tubers of 13 varieties of potato (Solanum tuberosum), which had been produced in a field trial in 2010 and sampled immediately after harvest or after storage for 6 months, were analysed to show the relationship between the concentrations of free asparagine, other free amino acids, sugars and acrylamide-forming potential. The varieties comprised five that are normally used for crisping, seven that are used for French fry production and one that is used for boiling. Acrylamide formation was measured in heated flour, and correlated with glucose and fructose concentration. In French fry varieties, which contain higher concentrations of sugars, acrylamide formation also correlated with free asparagine concentration, demonstrating the complex relationship between precursor concentration and acrylamide-forming potential in potato. Storage of the potatoes for 6 months at 9°C had a significant, variety-dependent impact on sugar and amino acid concentrations and acrylamide-forming potential. PMID:25540460

  8. Determination of size- and number-based concentration of silica nanoparticles in a complex biological matrix by online techniques.

    PubMed

    Bartczak, Dorota; Vincent, Phil; Goenaga-Infante, Heidi

    2015-06-01

    We propose for the first time methodology for the determination of a number-based concentration of silica (SiO2) nanoparticles (NP) in biological serum using nanoparticle tracking analysis (NTA) as the online detector for asymmetric flow field-flow fractionation (AF4). The degree of selectivity offered by AF4 was found necessary to determine reliably number-based concentration of the measured NP in the complex matrix with a relative measurement error of 5.1% (as relative standard deviation, n = 3) and without chemical sample pretreatment. The simultaneous online coupling to other size and concentration detectors, such as multiangle light scattering (MALS) and ICPMS, for the measurement of the same NP suspension, was used to confirm the particle size determined with NTA and the equivalent particle number determined by AF4/NTA, respectively. The size- and number-based concentration data obtained by independent techniques were in a good agreement. The developed methodology can easily be extended to other types of particles or particle suspensions and other complex matrices provided that the particle size is above the limit of detection for NTA. PMID:25970520

  9. Modeling Interactions among Individual P2 Receptors to Explain Complex Response Patterns over a Wide Range of ATP Concentrations

    PubMed Central

    Xing, Shu; Grol, Matthew W.; Grutter, Peter H.; Dixon, S. Jeffrey; Komarova, Svetlana V.

    2016-01-01

    Extracellular ATP acts on the P2X family of ligand-gated ion channels and several members of the P2Y family of G protein-coupled receptors to mediate intercellular communication among many cell types including bone-forming osteoblasts. It is known that multiple P2 receptors are expressed on osteoblasts (P2X2,5,6,7 and P2Y1,2,4,6). In the current study, we investigated complex interactions within the P2 receptor network using mathematical modeling. To characterize individual P2 receptors, we extracted data from published studies of overexpressed human and rodent (rat and mouse) receptors and fit their dependencies on ATP concentration using the Hill equation. Next, we examined responses induced by an ensemble of endogenously expressed P2 receptors. Murine osteoblastic cells (MC3T3-E1 cells) were loaded with fluo-4 and stimulated with varying concentrations of extracellular ATP. Elevations in the concentration of cytosolic free calcium ([Ca2+]i) were monitored by confocal microscopy. Dependence of the calcium response on ATP concentration exhibited a complex pattern that was not explained by the simple addition of individual receptor responses. Fitting the experimental data with a combination of Hill equations from individual receptors revealed that P2Y1 and P2X7 mediated the rise in [Ca2+]i at very low and high ATP concentrations, respectively. Interestingly, to describe responses at intermediate ATP concentrations, we had to assume that a receptor with a K1∕2 in that range (e.g. P2Y4 or P2X5) exerts an inhibitory effect. This study provides new insights into the interactions among individual P2 receptors in producing an ensemble response to extracellular ATP. PMID:27468270

  10. Livedoid vasculopathy associated with combined prothrombin G20210A and factor V (Leiden) heterozygosity and MTHFR C677T homozygosity.

    PubMed

    Irani-Hakime, Noha A; Stephan, Farid; Kreidy, Raghid; Jureidini, Isabelle; Almawi, Wassim Y

    2008-08-01

    Livedoid vasculopathy (LV) is an occlusive thrombotic disease of lower extremities. A 34-year-old woman presented with 4-year history of recurrent necrotic and painful lesions with violaceous and purpuric border on both legs. Initial treatment with hydroxychloroquine, dapsone and prednisone were unsuccessful. Skin biopsy showed inflammatory infiltrate with epidermal necrosis. Prothrombin G20210A and factor V-Leiden heterozygosity, and MTHFR C677T homozygosity with hyperhomocysteinemia were confirmed. LV diagnosis was made; acetylsalicylic acid, folic acid, vitamin B12, and prednisone treatement resulted in complete healing. This is the first report on coexistence of prothrombin G20210A, factor V-Leiden, and homozygous MTHFR C677T with hyperhomocysteinemia in LV. PMID:18360788

  11. Prevalence of factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations in 200 healthy Jordanians.

    PubMed

    Eid, Suhair S; Rihani, Ghada

    2004-01-01

    Thrombophilia is now considered a multi-causal condition, with interplay of acquired genetic risk factors. In order to estimate the frequency of the factor V Leiden, prothrombin G20210A, and MTHFR C677T mutations in the Jordanian population, we screened 200 healthy Jordanian individuals. 40% were females. Mean age was 32.1 years for males and 30.0 years for female participants. A PCR method detected 15.0% factor V Leiden (87% heterozygous, 13% homozygous), 2% prothrombin G20210A (100% heterozygous), and 24% MTHFR C677T (67% heterozygous, 33% homozygous). We conclude that the prevalence of factor V Leiden and MTHFR C677T is elevated in this population of Jordanians. However the incidence of G20210A is relatively low. Quantification of these genetic thrombosis risk factors in various populations will contribute to a better understanding of the interaction of genetic and environmental risk factors. PMID:15559724

  12. Optimization of dielectrophoretic separation and concentration of pathogens in complex biological samples

    NASA Astrophysics Data System (ADS)

    Bisceglia, E.; Cubizolles, M.; Mallard, F.; Pineda, F.; Francais, O.; Le Pioufle, B.

    2013-05-01

    Sample preparation is a key issue of modern analytical methods for in vitro diagnostics of diseases with microbiological origins: methods to separate bacteria from other elements of the complex biological samples are of great importance. In the present study, we investigated the DEP force as a way to perform such a de-complexification of the sample by extracting micro-organisms from a complex biological sample under a highly non-uniform electric field in a micro-system based on an interdigitated electrodes array. Different parameters were investigated to optimize the capture efficiency, such as the size of the gap between the electrodes and the height of the capture channel. These parameters are decisive for the distribution of the electric field inside the separation chamber. To optimize these relevant parameters, we performed numerical simulations using COMSOL Multiphysics and correlated them with experimental results. The optimization of the capture efficiency of the device has first been tested on micro-organisms solution but was also investigated on human blood samples spiked with micro-organisms, thereby mimicking real biological samples.

  13. Low micromolar concentrations of the superoxide probe MitoSOX uncouple neural mitochondria and inhibit complex IV.

    PubMed

    Roelofs, Brian A; Ge, Shealinna X; Studlack, Paige E; Polster, Brian M

    2015-09-01

    MitoSOX Red is a fluorescent probe used for the detection of mitochondrial reactive oxygen species by live cell imaging. The lipophilic, positively charged triphenylphosphonium moiety within MitoSOX concentrates the superoxide-sensitive dihydroethidium conjugate within the mitochondrial matrix. Here we investigated whether common MitoSOX imaging protocols influence mitochondrial bioenergetic function in primary rat cortical neurons and microglial cell lines. MitoSOX dose-dependently uncoupled neuronal respiration, whether present continuously in the assay medium or washed following a ten minute loading protocol. Concentrations of 5-10μM MitoSOX caused severe loss of ATP synthesis-linked respiration. Redistribution of MitoSOX to the cytoplasm and nucleus occurred concomitant to mitochondrial uncoupling. MitoSOX also dose-dependently decreased the maximal respiration rate and this impairment could not be rescued by delivery of a complex IV specific substrate, revealing complex IV inhibition. As in neurons, loading microglial cells with MitoSOX at low micromolar concentrations resulted in uncoupled mitochondria with reduced respiratory capacity whereas submicromolar MitoSOX had no adverse effects. The MitoSOX parent compound dihydroethidium also caused mitochondrial uncoupling and respiratory inhibition at low micromolar concentrations. However, these effects were abrogated by pre-incubating dihydroethidium with cation exchange beads to remove positively charged oxidation products, which would otherwise by sequestered by polarized mitochondria. Collectively, our results suggest that the matrix accumulation of MitoSOX or dihydroethidium oxidation products causes mitochondrial uncoupling and inhibition of complex IV. Because MitoSOX is inherently capable of causing severe mitochondrial dysfunction with the potential to alter superoxide production, its use therefore requires careful optimization in imaging protocols. PMID:26057935

  14. Comparative study of a portable prothrombin time monitor employing three different systems in oral anticoagulant units.

    PubMed

    Vacas, M; Fernández, M A; Martínez-Brotons, F; Lafuente, P J; Ripoll, F; Alvarez, C; Iriarte, J A

    2001-01-01

    The aim of this study was to evaluate the accuracy of the portable coagulometer CoaguChek (Roche Diagnostics) as a prothrombin time (PT) monitor, and to correlate capillary blood results with those of three different routine methods used for monitoring oral anticoagulant therapy (OAT): capillary, plasma and whole blood samples. Three hospitals participated in the study with a total of 235 patients on OAT. The international normalized ratio (INR) results obtained with CoaguChek were compared with those obtained using each of the routine methods. The study presents a good correlation between the PT monitor and the three methods studied: r = 0.9745 (hospital A), r = 0.9283 (hospital B), r = 0.9136 (hospital C). A simplified concordance test of the methods results in a nine-field comparison table showing concordances of 87.2, 85.7 and 68.4%, respectively. The absolute difference (mean +/- SD) between laboratory A and CoaguChek INRs was 0.0571 +/- 0.2042, with values of 0.04286 +/- 0.3906 for laboratory B and 0.6986 +/- 0.6170 for laboratory C. These results confirm that CoaguChek could be used as a new method for oral anticoagulant monitoring, and is in best agreement with the capillary blood PT system. PMID:11408745

  15. Comparison of Prothrombin Time and Aspartate Aminotransferase in Predicting Hepatotoxicity After Acetaminophen Overdose.

    PubMed

    Levine, Michael; O'Connor, Ayrn D; Padilla-Jones, Angela; Gerkin, Richard D

    2016-03-01

    Despite decades of experience with acetaminophen (APAP) overdoses, it remains unclear whether elevated hepatic transaminases or coagulopathy develop first. Furthermore, comparison of the predictive value of these two variables in determining hepatic toxicity following APAP overdoses has been poorly elucidated. The primary objective of this study is to determine the test characteristics of the aspartate aminotransferase (AST) and the prothrombin time (PT) in patients with APAP toxicity. A retrospective chart review of APAP overdoses treated with IV N-acetylcysteine at a tertiary care referral center was performed. Of the 304 subjects included in the study, 246 with an initial AST less than 1000 were analyzed to determine predictors of hepatic injury, defined as an AST exceeding 1000 IU/L. The initial AST >50 was 79.5 % sensitive and 82.6 % specific for predicting hepatic injury. The corresponding negative and positive predictive values were 95.5 and 46.3 %, respectively. In contrast, an initial abnormal PT had a sensitivity of 82.1 % and a specificity of 63.6 %. The negative and positive predictive values for initial PT were 94.9 and 30.2 %, respectively. Although the two tests performed similarly for predicting a composite endpoint of death or liver transplant, neither was a useful predictor. Initial AST performed better than the initial PT for predicting hepatic injury in this series of patients with APAP overdose. PMID:26341088

  16. The effects of proton radiation on the prothrombin and partial thromboplastin times of irradiated ferrets

    PubMed Central

    Krigsfeld, Gabriel S.; Sanzari, Jenine K.; Kennedy, Ann R.

    2013-01-01

    Purpose To determine whether proton radiation affects coagulation. Material and methods Ferrets were exposed to solar particle event-like proton radiation at doses of 0, 25, 100, or 200 centigray (cGy), and dose rates of 50 cGy/minute (high dose rate or HDR) or 50 cGy/hour (low dose rate or LDR). Plasma was isolated from blood collected prior to radiation exposure and at 3–7 h post-radiation. Prothrombin time (PT) assays and activated partial thromboplastin time (aPTT) assays were performed as were mixing studies to determine the coagulation factors involved. Results HDR and LDR exposure led to statistically significant increases in PT values. It was determined that the HDR-induced increase in PT was due to Factor VII, while Factors II, V, and VII contributed to the LDR-induced increase in PT values. Only acute LDR exposure caused an increase in aPTT values, which remained elevated for 48 h post-irradiation (which was the latest time assayed in these studies). Mixing studies revealed that Factor IX contributed to the increased aPTT values. A majority of the animals exposed at the LDR had an International Normalized Ratio approaching or surpassing 2.0. Conclusions PT/aPTT assays resulted in increased clotting times due to different coagulation factors, indicating potential radiation-induced coagulopathy. PMID:22221163

  17. Immunomagnetic Reduction Assay on Des-Gamma-Carboxy Prothrombin for Screening of Hepatocellular Carcinoma.

    PubMed

    Chieh, Jen-Jie; Huang, K W; Chuang, C P; Wei, W C; Dong, J J; Lee, Y Y

    2016-08-01

    The accredited biomarker alpha-fetoprotein (AFP) offers limited sensitivity and specificity in the early detection of hepatocellular carcinoma (HCC). To improve the screening performance, des-gamma-carboxy prothrombin (DCP) has been identified as another promising biomarker of HCC, combined with AFP biomarkers. The results of the commercial optical enzyme-linked immunosorbent assay (ELISA) kit easily have the interference problem due to the optical methodology. The immunomagnetic reduction (IMR) assay based on the magnetic measurement was utilized to assay DCP biomarkers without the excellent antiinterference performances. A DCP magnetic reagent, composed of iron-oxide (Fe3O4 ) magnetic nanoparticles coated with anti-DCP antibodies solved in phosphoryl-buffer solution, was synthesized and characterized. In the test of standard DCP antigens, superior antiinterference and sensitivity than optical ELISA were proved. In the animal test, the results indicate good agreement between the IMR assay findings and the tumor sizes of HCC rats at all time points after the HCC implantation. The feasibility of the developed DCP magnetic reagent with the IMR for the detection of DCP is verified, and demonstrates the high potential for future clinical applications. PMID:26415145

  18. Takayasu Arteritis With Antiphosphatidylserine/Prothrombin Antibody-Positive Antiphospholipid Syndrome: Case Report and Literature Review.

    PubMed

    Fukui, Shoichi; Hirota, Shogo; Iwamoto, Naoki; Karata, Hiroki; Kawakami, Atsushi

    2015-12-01

    A relationship between Takayasu arteritis (TA) and positive antiphospholipid antibody states has been pointed out, but patients with TA complicated with antiphospholipid antibody syndrome (APS) are rare. Here we report the case of a 17-year-old Japanese man diagnosed with TA based on pulselessness of the left brachial artery, discrepancy of blood pressure between the upper extremities, and arterial wall thickening and narrowing of artery in contrast computed tomography. He was also diagnosed with provisional APS based on a pulmonary infarction without narrowing of the pulmonary artery and positive antiphosphatidylserine/prothrombin antibody. The patient also had concurrent Crohn's disease (CD) based on histopathological findings, which may have been associated with TA. We started high-dose corticosteroid therapy and anticoagulation therapy, and his symptoms including fever, dizziness, chest pain, and lower-right uncomfortable abdomen improved.We reviewed 9 cases of TA with APS including our patient by conducting a PubMed search. Based on past reports, we considered the relationship among TA, APS, and CD.Clinicians should bear in mind that many etiologies can exist in 1 patient, and differential diagnoses are essential. PMID:26705229

  19. Electron probe microanalysis of the dopant concentrations in complex perovskite ferroelectrics

    NASA Astrophysics Data System (ADS)

    Samardžija, Z.

    2016-02-01

    Quantitative EPMA-WDS microanalyses were applied for the compositional characterisation of complex perovskite ferroelectrics based on cerium-doped barium titanate, a solid solution between lead-magnesium-niobate/lead-titanate and niobium-doped barium- bismuth-titanate. The analyses were optimized for high analytical sensitivity, precision and an ultimate accuracy of ≈ ± 1 % relative. The inherent problem with the WDS peak overlap of the Ce-Lα1 and Ba-Lβ1,4 spectral lines was solved by introducing overlap-correction methods in order to obtain consistent quantitative results for the Ce-doped BaTiO3. The quantitative results made it possible to obtain accurate chemical formulae for these materials, to determine the solubility of the dopants as well as to define the mode of the dopant incorporation and the charge-compensation mechanisms.

  20. Concentrations of selected chlorinated pesticides in shrimp collected from the Calcasieu River/Lake Complex, Louisiana

    SciTech Connect

    Murray, H.E.; Beck, J.N. )

    1990-05-01

    For several decades inland and coastal aquatic ecosystems have been affected by a multitude of synthetic chemical substances. This is a consequence of population growth and increased industrial and agricultural activity. Many of these chemicals, the by-products of their production, and degradation products ultimately find their way into the aquatic environment as pollutants. The extent to which these pollutants affect the environment and its inhabitants depends largely upon the quantity and nature of the particular compounds involved. Halogenated hydrocarbons, particularly polychlorinated biphenyls (PCBs), and the pesticide DDT and its degradation products have received much attention as environmental pollutants. Because of the economic importance of the shrimping industry to southwest Louisiana, the objective of this study was to analyze shrimp collected from the Calcasieu River/Lake Complex for the presence of selected chlorinated pesticides. The presence of these compounds within shrimp tissues would serve as an indicator for the extent of pollution throughout this important estuarine system.

  1. Determination of metal ion concentrations by SERS using 2,2'-bipyridyl complexes.

    PubMed

    Docherty, Julie; Mabbott, Samuel; Smith, W Ewen; Reglinski, John; Faulds, Karen; Davidson, Christine; Graham, Duncan

    2015-10-01

    Surface enhanced Raman scattering (SERS) can generate characteristic spectral "fingerprints" from metal complexes, thus providing the potential for the development of methods of analysis for the identification and quantitation of a range of metal ions in solution. The advantages include sensitivity and the use of one ligand for several metals without the need for a specific chromophore. Aqueous solutions of Fe(II), Ni(II), Zn(II), Cu(II), Cr(III) and Cd(II) in the presence of excess 2,2'-bipyridyl (bipy) were analysed using SERS. Specific marker bands enabled the identification of each metal ion and the limit of detection for each metal ion was estimated. Two of the ions, Zn(II) and Cu(II), could be detected below the World Health Organisation's (WHO) recommended limits for drinking water at levels of 0.22 and 0.6 mg L(-1), respectively. PMID:26312259

  2. Uptake of intact zinc-ethylenediaminetetraacetic acid from soil is dependent on plant species and complex concentration.

    PubMed

    Collins, Richard N; Merrington, Graham; McLaughlin, Mike J; Knudsen, Chris

    2002-09-01

    Pot experiments were conducted with barley (Hordeum vulgare L.), potato (Solanum tuberosum L.), Indian mustard (Brassicajuncea L.), and white lupin (Lupinus albus L.) to determine the nature of Zn mobilization, uptake, and root-shoot transport from a Zn-contaminated soil in the presence of increasing concentrations of ethylenediaminetetraacetic acid (EDTA; 0.0-3.4 mmole/kg soil). Increasing EDTA concentrations lead to a greater proportion of soil-solution Zn being detected as the ZnEDTA complex. However, a significant increase in the concentration of soil-solution Zn was only observed after the addition of 3.4 mmole EDTA/ kg soil. At this application rate, regardless of the plant species, 97 +/- 9% (+/- SD) of the increase in soil-solution Zn could be accounted for by chelation/desorption, and 89 +/- 9% of total Zn in solution was measured as ZnEDTA. Although the complex was detected in the xylem exudate of B. juncea after 0.34 mmole EDTA/kg soil had been added, ZnEDTA was only found in the xylem exudate of the other plant species following the highest application rate of EDTA. In this case, the accumulation of Zn and the concentration of ZnEDTA in the xylem sap of B. juncea were significantly greater than those of H. vulgare and S. tuberosum. Measurements of plant transpiration following the addition of EDTA indicated that B. juncea experienced greater physiological stress in the presence of high concentrations of EDTA. It was therefore concluded that two different mechanisms of ZnEDTA uptake existed for these plant species. Based on a review of the literature, it was hypothesized that uptake of ZnEDTA by B. juncea occurred only after physiological damage to its root system, whereas uptake by H. vulgare and S. tuberosum was via an apoplastic pathway (passive extracellular transport into the xylem). PMID:12206435

  3. Complex patterns in fish - sediment mercury concentrations in a contaminated estuary: The influence of selenium co-contamination?

    NASA Astrophysics Data System (ADS)

    Jones, H. J.; Swadling, K. M.; Butler, E. C. V.; Macleod, C. K.

    2014-01-01

    Environmental mercury (Hg) loads do not always correspond to Hg concentrations in resident fish and selenium (Se) presence has been reported to play a pivotal role in mitigating Hg bioaccumulation. Total mercury (THg), methylmercury (MeHg) and Se concentrations were measured in sediments and a benthic fish species (Platycephalus bassensis) from a contaminated estuary (Derwent Estuary, Tasmania). Elevated sediment concentrations of Se did not result in increased Se concentrations in fish, but low concentrations of Se were associated with increased MeHg bioavailability (% MeHg) from sediments to fish. Where MeHg (≈99% of total Hg) concentration in fish was high Se uptake also increased, indicating that maintaining positive Se:Hg ratios may reduce the toxicity of MeHg. MeHg was detectable in sediments throughout the estuary, and a molar excess of THg over Se suggested that there was insufficient Se to prevent methylation from the sediments. Se:Hg ratios of less than 1.0 in sediments, coupled with high %MeHg fraction and high biotic sediment accumulation factors for MeHg (BSAFMeHg), indicated that the lower region of the Derwent Estuary could be a hotspot for Hg methylation, despite having significantly lower THg concentrations. In contrast, Hg bioavailability to fish from sediments close to the source may be reduced by both inorganic Hg species complexation and lower methylation rates. There was a strong association between THg and Se in estuarine sediments, suggesting that Se plays an important role in sediment Hg cycling and should be a key consideration in any future assessments of Hg methylation, bioavailability and bioaccumulation.

  4. Reconstructing the recent failure chronology of a multistage landslide complex using cosmogenic isotope concentrations: St Catherine's Point, UK

    NASA Astrophysics Data System (ADS)

    Barlow, John; Moore, Roger; Gheorghiu, Delia M.

    2016-09-01

    The pre-existing multistage landslide complex at St Catherine's Point comprises a series of large rotational and translational failures that form the western section of the Isle of Wight Undercliff, UK. Cosmogenic beryllium and aluminum concentrations extracted from chert samples of the Upper Greensand are used to date the most recent sequential failure events. We use our understanding of the failure mechanics and landslide geomorphology to produce a cosmogenic exposure model that incorporates pre-failure topography into our shielding calculations. This method allowed us to date two successive landslides at the site using 10Be, the most recent of which occurred ~ 1064 ± 348 (± 1 σ) 10Be years ago, much more recently than was previously thought. An earlier failure event is dated at ~ 3471 ± 348 10Be years, supporting the hypothesis that the St Catherine's Point landslide complex was reactivated by relative sea-level rise at the end of the Holocene Climatic Optimum period.

  5. Variation in predicted internal concentrations in relation to PBPK model complexity for rainbow trout.

    PubMed

    Salmina, E S; Wondrousch, D; Kühne, R; Potemkin, V A; Schüürmann, G

    2016-04-15

    The present study is motivated by the increasing demand to consider internal partitioning into tissues instead of exposure concentrations for the environmental toxicity assessment. To this end, physiologically based pharmacokinetic (PBPK) models can be applied. We evaluated the variation in accuracy of PBPK model outcomes depending on tissue constituents modeled as sorptive phases and chemical distribution tendencies addressed by molecular descriptors. The model performance was examined using data from 150 experiments for 28 chemicals collected from US EPA databases. The simplest PBPK model is based on the "Kow-lipid content" approach as being traditional for environmental toxicology. The most elaborated one considers five biological sorptive phases (polar and non-polar lipids, water, albumin and the remaining proteins) and makes use of LSER (linear solvation energy relationship) parameters to describe the compound partitioning behavior. The "Kow-lipid content"-based PBPK model shows more than one order of magnitude difference in predicted and measured values for 37% of the studied exposure experiments while for the most elaborated model this happens only for 7%. It is shown that further improvements could be achieved by introducing corrections for metabolic biotransformation and compound transmission hindrance through a cellular membrane. The analysis of the interface distribution tendencies shows that polar tissue constituents, namely water, polar lipids and proteins, play an important role in the accumulation behavior of polar compounds with H-bond donating functional groups. For compounds without H-bond donating fragments preferable accumulation phases are storage lipids and water depending on compound polarity. PMID:26849323

  6. Glucose, fructose and sucrose increase the solubility of protein-tannin complexes and at high concentration, glucose and sucrose interfere with bisulphite bleaching of wine pigments.

    PubMed

    Harbertson, James F; Yuan, Chunlong; Mireles, Maria S; Hanlin, Rachel L; Downey, Mark O

    2013-05-01

    Wines were modified with increasing sugar concentrations and decreasing tannin concentrations and analysed by a combination of protein precipitation and bisulphite bleaching. Increasing sugar concentration decreased the precipitation of tannin and protein-precipitable polymeric pigments (PPP). The use of a hydrogen bond disruptor (urea) to reduce protein-tannin and protein-pigment complex formation showed that the effect of sugar concentration occurred by increasing the solubility of the tannin-protein complex, not by interfering with protein-tannin complex formation. By increasing the solubility of pigment-protein complexes, non-protein-precipitable polymeric pigments (nPPP) appeared to increase. There was also an increase in total polymeric pigments at each tannin concentration with increasing glucose and sucrose concentration, indicating that sugar concentration might also affect bisulphite bleaching of wine pigments. While a significant effect of sugar concentration on tannin-protein complex solubility was observed, these effects were greatest at sugar concentrations far in excess of normal wine making conditions. Under normal wine making conditions, sugar concentration will have a negligible effect on protein-precipitable tannin, PPP and nPPP concentrations. PMID:23265524

  7. Saturation fluorimetry of complex organic compounds with a high local concentration of fluorophores (by the example of phytoplankton)

    SciTech Connect

    Maslov, D V; Ostroumov, E E; Fadeev, V V

    2006-02-28

    Saturation of fluorescence of complex organic compounds with a high local concentration of fluorescing molecules (fluorophores), when singlet-singlet annihilation makes a noticeable contribution to saturation, is considered. The fluorescence saturation curve is obtained analytically for the case of a rectangular temporal and spatial distribution of photons in a laser pulse. It is shown that the fluorescence saturation curve depends on the parameter {Phi}{sub 0}, which is proportional to the concentration of fluorescing molecules, and on the parameters A, B, and {alpha} describing the influence of singlet-singlet annihilation, bleaching of an optically thin layer, and nonstationarity of excitation, respectively. The fluorescence saturation curves are studied experimentally for compounds with a high local concentration of fluorescing molecules such as molecules of a monoculture of diatomic alga Thalassiosira weissflogii. The experimental fluorescence saturation curves are well described by the obtained analytic expression. The values of the parameter {Phi}{sub 0}, proportional to the concentration of chlorophyll a, and the parameter A (for the first time) are obtained from the alga fluorescence saturation curves. (laser applications and other topics in quantum electronics)

  8. Spectral determination of concentrations of functionally diverse pigments in increasingly complex arctic tundra canopies.

    PubMed

    Boelman, Natalie T; Magney, Troy S; Logan, Barry A; Griffin, Kevin L; Eitel, Jan U H; Greaves, Heather; Prager, Case M; Vierling, Lee A

    2016-09-01

    As the Arctic warms, tundra vegetation is becoming taller and more structurally complex, as tall deciduous shrubs become increasingly dominant. Emerging studies reveal that shrubs exhibit photosynthetic resource partitioning, akin to forests, that may need accounting for in the "big leaf" net ecosystem exchange models. We conducted a lab experiment on sun and shade leaves from S. pulchra shrubs to determine the influence of both constitutive (slowly changing bulk carotenoid and chlorophyll pools) and facultative (rapidly changing xanthophyll cycle) pigment pools on a suite of spectral vegetation indices, to devise a rapid means of estimating within canopy resource partitioning. We found that: (1) the PRI of dark-adapted shade leaves (PRIo) was double that of sun leaves, and that PRIo was sensitive to variation among sun and shade leaves in both xanthophyll cycle pool size (V + A + Z) (r (2) = 0.59) and Chla/b (r (2) = 0.64); (2) A corrected PRI (difference between dark and illuminated leaves, ΔPRI) was more sensitive to variation among sun and shade leaves in changes to the epoxidation state of their xanthophyll cycle pigments (dEPS) (r (2) = 0.78, RMSE = 0.007) compared to the uncorrected PRI of illuminated leaves (PRI) (r (2) = 0.34, RMSE = 0.02); and (3) the SR680 index was correlated with each of (V + A + Z), lutein, bulk carotenoids, (V + A + Z)/(Chla + b), and Chla/b (r (2) range = 0.52-0.69). We suggest that ΔPRI be employed as a proxy for facultative pigment dynamics, and the SR680 for the estimation of constitutive pigment pools. We contribute the first Arctic-specific information on disentangling PRI-pigment relationships, and offer insight into how spectral indices can assess resource partitioning within shrub tundra canopies. PMID:27193900

  9. Modeling the human prothrombinase complex components

    NASA Astrophysics Data System (ADS)

    Orban, Tivadar

    Thrombin generation is the culminating stage of the blood coagulation process. Thrombin is obtained from prothrombin (the substrate) in a reaction catalyzed by the prothrombinase complex (the enzyme). The prothrombinase complex is composed of factor Xa (the enzyme), factor Va (the cofactor) associated in the presence of calcium ions on a negatively charged cell membrane. Factor Xa, alone, can activate prothrombin to thrombin; however, the rate of conversion is not physiologically relevant for survival. Incorporation of factor Va into prothrombinase accelerates the rate of prothrombinase activity by 300,000-fold, and provides the physiological pathway of thrombin generation. The long-term goal of the current proposal is to provide the necessary support for the advancing of studies to design potential drug candidates that may be used to avoid development of deep venous thrombosis in high-risk patients. The short-term goals of the present proposal are to (1) to propose a model of a mixed asymmetric phospholipid bilayer, (2) expand the incomplete model of human coagulation factor Va and study its interaction with the phospholipid bilayer, (3) to create a homology model of prothrombin (4) to study the dynamics of interaction between prothrombin and the phospholipid bilayer.

  10. Restoration of Normal Prothrombin Time/International Normalized Ratio With Fresh Frozen Plasma in Hypocoagulable Patients.

    PubMed

    Only, Arthur J; DeChristopher, Phillip J; Iqal, Omer; Fareed, Jawed

    2016-01-01

    Fresh frozen plasma (FFP) is an effective reversal agent for hypocoagulable patients. Its proven efficacy continues to prompt its usage as both a prophylactic and a therapeutic therapy. Although published guidelines encouraging the appropriate administration of FFP exist, overutilization continues. The purpose of these ex vivo studies was to determine the effects of succeeding volumes of FFP supplementation on hypocoagulable plasma prothrombin time/international normalized ratio (PT/INR). By analyzing the decline in PT/INR with varying volumes of FFP, a minimal required volume of FFP could be identified representing the optimal volume to administer while still providing therapeutic effect. A total of 497 plasma samples were screened for elevated PT/INR values and 50 samples were selected for inclusion in this experiment. The initial PTs/INRs ranged from 12.5 to 43.4 seconds/1.42 to 4.91. Subsequent declines in PT/INR values were analyzed following addition of 50, 100, and 150 µL of FFP to a fixed volume of 250 µL of plasma (26.4 ± 5.318 seconds/2.99 ± 0.603, 13.3 ± 1.077 seconds/1.51 ± 0.122, 11.2 ± 0.712 seconds/1.27 ± 0.081, and 10.3 ± 0.533 seconds/1.16 ± 0.06, respectively). A nonlinear relationship between decline in INR values and percentage of FFP supplementation was demonstrated. The greatest effect on INR was obtained after supplementation with 50 µL (49%). Doubling and tripling the volume of FFP lead to significantly lower declines in INR (16% and 8%, respectively). Analysis of variance indicated a statistical significance with subsequent volume supplementation of FFP, but marginal clinical benefits exist between the PTs/INRs obtainable with increased FFP volume administration. PMID:25294634

  11. A Systematic Review of Des-γ-Carboxy Prothrombin for the Diagnosis of Primary Hepatocellular Carcinoma.

    PubMed

    De, Ji; Shen, Yi; Qin, Jinyu; Feng, Li; Wang, Yiping; Yang, Li

    2016-04-01

    Determining the serum des-γ-carboxy-prothrombin (DCP) level is of great importance for the diagnosis of primary hepatocellular carcinoma (PHC). Although several studies have investigated the accuracy of diagnostic DCP tests for PHC, the results have been inconsistent.The aim of this study was to systematically evaluate DCP as a diagnostic standard for PHC.Several databases, including PubMed, EMBASE, MEDLINE (Ovid), the Chinese National Knowledge Infrastructure (CNKI), the VIP Database for Chinese Technical Periodicals (VIP), WanFang Data, and the China Biological Medicine Database (CBM), were searched from the date of database inception until July 1, 2015 to collect published international and domestic studies of DCP in the diagnosis of PHC. Two investigators screened the literature according to the inclusion and exclusion criteria, extracted the data, and assessed the methodological quality of the included studies.A total of 38 studies involving 11,124 cases were included (5298 cases in the PHC group and 5826 cases in the control group). A meta-analysis was then performed using Meta-Disc 1.4 and RevMan 5.2 software. The overall sensitivity, specificity, positive likelihood ratio (+LR), and negative likelihood ratio (-LR) of DCP for the detection of PHC were 0.66 (95% confidence interval [CI]: 0.65-0.68), 0.88 (95% CI: 0.87-0.90), 7.13 (95% CI: 5.73-8.87), and 0.33 (95% CI: 0.29-0.38), respectively. The area under the curve (AUC) of the summary receiver-operating characteristic curve (SROC) was 0.9002. In conclusion, DCP has moderate diagnostic utility for PHC. Owing to the heterogeneity and limitations of the included studies, the above conclusion requires further support from additional high-quality studies. PMID:27124038

  12. A Systematic Review of Des-γ-Carboxy Prothrombin for the Diagnosis of Primary Hepatocellular Carcinoma

    PubMed Central

    De, Ji; Shen, Yi; Qin, Jinyu; Feng, Li; Wang, Yiping; Yang, Li

    2016-01-01

    Abstract Determining the serum des-γ-carboxy-prothrombin (DCP) level is of great importance for the diagnosis of primary hepatocellular carcinoma (PHC). Although several studies have investigated the accuracy of diagnostic DCP tests for PHC, the results have been inconsistent. The aim of this study was to systematically evaluate DCP as a diagnostic standard for PHC. Several databases, including PubMed, EMBASE, MEDLINE (Ovid), the Chinese National Knowledge Infrastructure (CNKI), the VIP Database for Chinese Technical Periodicals (VIP), WanFang Data, and the China Biological Medicine Database (CBM), were searched from the date of database inception until July 1, 2015 to collect published international and domestic studies of DCP in the diagnosis of PHC. Two investigators screened the literature according to the inclusion and exclusion criteria, extracted the data, and assessed the methodological quality of the included studies. A total of 38 studies involving 11,124 cases were included (5298 cases in the PHC group and 5826 cases in the control group). A meta-analysis was then performed using Meta-Disc 1.4 and RevMan 5.2 software. The overall sensitivity, specificity, positive likelihood ratio (+LR), and negative likelihood ratio (−LR) of DCP for the detection of PHC were 0.66 (95% confidence interval [CI]: 0.65–0.68), 0.88 (95% CI: 0.87–0.90), 7.13 (95% CI: 5.73–8.87), and 0.33 (95% CI: 0.29–0.38), respectively. The area under the curve (AUC) of the summary receiver-operating characteristic curve (SROC) was 0.9002. In conclusion, DCP has moderate diagnostic utility for PHC. Owing to the heterogeneity and limitations of the included studies, the above conclusion requires further support from additional high-quality studies. PMID:27124038

  13. Characterisation of sub-micron particle number concentrations and formation events in the western Bushveld Igneous Complex, South Africa

    NASA Astrophysics Data System (ADS)

    Hirsikko, A.; Vakkari, V.; Tiitta, P.; Manninen, H. E.; Gagné, S.; Laakso, H.; Kulmala, M.; Mirme, A.; Mirme, S.; Mabaso, D.; Beukes, J. P.; Laakso, L.

    2012-05-01

    South Africa holds significant mineral resources, with a substantial fraction of these reserves occurring and being processed in a large geological structure termed the Bushveld Igneous Complex (BIC). The area is also highly populated by informal, semi-formal and formal residential developments. However, knowledge of air quality and research related to the atmosphere is still very limited in the area. In order to investigate the characteristics and processes affecting sub-micron particle number concentrations and formation events, air ion and aerosol particle size distributions and number concentrations, together with meteorological parameters, trace gases and particulate matter (PM) were measured for over two years at Marikana in the heart of the western BIC. The observations showed that trace gas (i.e. SO2, NOx, CO) and black carbon concentrations were relatively high, but in general within the limits of local air quality standards. The area was characterised by very high condensation sink due to background aerosol particles, PM10 and O3 concentration. The results indicated that high amounts of Aitken and accumulation mode particles originated from domestic burning for heating and cooking in the morning and evening, while during daytime SO2-based nucleation followed by the growth by condensation of vapours from industrial, residential and natural sources was the most probable source for large number concentrations of nucleation and Aitken mode particles. Nucleation event day frequency was extremely high, i.e. 86% of the analysed days, which to the knowledge of the authors is the highest frequency ever reported. The air mass back trajectory and wind direction analyses showed that the secondary particle formation was influenced both by local and regional pollution and vapour sources. Therefore, our observation of the annual cycle and magnitude of the particle formation and growth rates during nucleation events were similar to results previously published for a semi

  14. Charge carrier effective mass and concentration derived from combination of Seebeck coefficient and Te125 NMR measurements in complex tellurides

    DOE PAGESBeta

    Levin, E. M.

    2016-06-27

    Thermoelectric materials utilize the Seebeck effect to convert heat to electrical energy. The Seebeck coefficient (thermopower), S, depends on the free (mobile) carrier concentration, n, and effective mass, m*, as S ~ m*/n2/3. The carrier concentration in tellurides can be derived from 125Te nuclear magnetic resonance (NMR) spin-lattice relaxation measurements. The NMR spin-lattice relaxation rate, 1/T1, depends on both n and m* as 1/T1~(m*)3/2n (within classical Maxwell-Boltzmann statistics) or as 1/T1~(m*)2n2/3 (within quantum Fermi-Dirac statistics), which challenges the correct determination of the carrier concentration in some materials by NMR. Here it is shown that the combination of the Seebeck coefficientmore » and 125Te NMR spin-lattice relaxation measurements in complex tellurides provides a unique opportunity to derive the carrier effective mass and then to calculate the carrier concentration. This approach was used to study AgxSbxGe50–2xTe50, well-known GeTe-based high-efficiency tellurium-antimony-germanium-silver thermoelectric materials, where the replacement of Ge by [Ag+Sb] results in significant enhancement of the Seebeck coefficient. Thus, values of both m* and n derived using this combination show that the enhancement of thermopower can be attributed primarily to an increase of the carrier effective mass and partially to a decrease of the carrier concentration when the [Ag+Sb] content increases.« less

  15. Analysis of Soluble Molecular Fibronectin-Fibrin Complexes and EDA-Fibronectin Concentration in Plasma of Patients with Atherosclerosis.

    PubMed

    Lemańska-Perek, Anna; Krzyżanowska-Gołąb, Dorota; Pupek, Małgorzata; Klimeczek, Piotr; Witkiewicz, Wojciech; Kątnik-Prastowska, Iwona

    2016-06-01

    Atherosclerosis, a chronic vascular disease, leads to molecular events bound with interplaying processes of inflammation and coagulation. In the present study, fibronectin (FN), FN containing extra domain A (EDA-FN), frequency of occurrence, and relative amounts of soluble plasma FN-fibrin complexes were analyzed in 80 plasma samples of patients suspected of coronary artery disease based on clinical evaluation and changes in arteries found by computed tomographic coronary angiography. The study showed that in the plasma of the patients' group with high risk of coronary artery disease EDA-FN concentration was significantly higher (3.5 ± 2.5 mg/L; P < 0.025) and the molecular FN-fibrin complexes of 1000 kDa and higher occurred more often than in the groups of patients with mild risk of coronary artery disease and the normal age-matched. The increased level of EDA-FN and occurrence of FN-fibrin complexes could have a potential diagnostic value in the diagnosis and management of patients with coronary artery disease. PMID:27022744

  16. Prevalence and Geographical Variation of Prothrombin G20210A Mutation in Patients with Cerebral Vein Thrombosis: A Systematic Review and Meta-Analysis

    PubMed Central

    Gonzalez, Joaquín V.; Barboza, Andrés G.; Vazquez, Fernando J.; Gándara, Esteban

    2016-01-01

    Objectives To compare the prevalence of prothrombin G20210A in patients with objectively confirmed cerebral vein or cortical vein thrombosis against healthy controls, and evaluate geographical variations. Design Systematic review and meta-analysis of case control studies. Methods We conducted a systematic review of electronic databases including MEDLINE and EMBASE. The main outcome was the prevalence of prothrombin G20210A in patients with objectively confirmed cerebral vein or cortical vein thrombosis; we also analyzed individual country variations in the prevalence. The random-effects model OR was used as the primary outcome measure. Results In total 19 studies evaluated 868 cases of cerebral venous thrombosis and 3981 controls. Prothrombin G20210A was found in 103/868 of the patients with cerebral venous thrombosis and 105/3999 of the healthy controls [random effects pooled OR 5.838, 95% CI 3.96 to 8.58; I217.9%]. The prevalence of prothrombin G20210A was significantly elevated in Italian studies (OR 9.69), in Brazilian studies (OR 7.02), and in German studies (OR 3.77), but not in Iranian studies (OR 0.98). Conclusion Prothrombin G20210A is significantly associated with cerebral venous thrombosis when compared to healthy controls, although this association is highly dependent on the country of origin. PMID:27031503

  17. D-Dimer and prothrombin fragment 1 + 2 in urine and plasma in patients with clinically suspected venous thromboembolism.

    PubMed

    Wexels, Fredrik; Seljeflot, Ingebjørg; Pripp, Are H; Dahl, Ola E

    2016-06-01

    Increased levels of urine prothrombin fragment 1 + 2 was recently reported to be associated with imaging-verified venous thromboembolism. In this study we evaluated the relationship between plasma D-dimer and plasma and urine prothrombin fragment 1 + 2 in patients with suspected venous thromboembolism. Urine and blood samples were collected from patients with suspected pulmonary embolism or deep vein thrombosis. The samples were analysed with commercially available ELISA kits. The diagnosis of venous thromboembolism was verified with contrast-enhanced computer tomography of the pulmonary arteries or lower extremity deep vein compression ultrasound and venography as appropriate. Venous thromboembolism was diagnosed in 150 of 720 patients. Significantly higher levels of plasma D-dimer and prothrombin fragment 1 + 2 in plasma and urine were found in those with imaging-confirmed venous thromboembolism versus those without (P < 0.001). The correlation between the three biomarkers was statistically significant (range of rs values 0.45-0.65, P < 0.001). Plasma D-dimer had the highest diagnostic accuracy followed by prothrombin fragment 1 + 2 in plasma. Further development of ELISA analyses for urine testing of prothrombin fragment 1 + 2 may improve its diagnostic accuracy. PMID:26595215

  18. Fiber optic immunosensor for cross-linked fibrin concentration

    NASA Astrophysics Data System (ADS)

    Moskowitz, Samuel E.

    2000-08-01

    Working with calcium ions in the blood, platelets produce thromboplastin which transforms prothrombin into thrombin. Removing peptides, thrombin changes fibrinogen into fibrin. Cross-linked insoluble fibrin polymers are solubilized by enzyme plasmin found in blood plasma. Resulting D-dimers are elevated in patients with intravascular coagulation, deep venous thrombosis, pulmonary embolism, myocardial infarction, multiple trauma, cancer, impaired renal and liver functions, and sepsis. Consisting principally of a NIR 780 nm GaAlAs laser diode and a 800 nm avalanche photodiode (APD), the fiber-optic immunosensor can determined D-dimer concentration to levels <0.1 ng/ml. A capture monoclonal antibody to the antigen soluble cross-linked fibrin is employed. Immobilized at the tip of an optical fiber by avidin-biotin, the captured antigen is detected by a second antibody which is labeled with NN 382 fluorescent dye. An evanescent wave traveling on an excitation optical fiber excites the antibody-antigen fluorophore complex. Concentration of cross-linked fibrin is directly proportional to the APD measured intensity of fluorescence. NIR fluorescence has advantages of low background interference, short fluorescence lifetime, and large difference between excitation and emission peaks. Competitive ELISA test for D-dimer concentration requires trained personnel performing a time consuming operation.

  19. MTHFR C677T and prothrombin G20210A mutations in a woman from Dalmatia with silent brain infarction. .

    PubMed

    Ivica, Nikolina; Pintarić, Irena; Titlić, Marina

    2014-09-01

    A 55-year-old, previously healthy woman, presented with frequent headaches. She had no neurological disturbances, but had a positive family history; her father died from stroke. Magnetic resonance imaging showed brain infarction; therefore detailed diagnostic evaluation of thrombophilia markers and genetic testing were performed. The patient was found to be homozy- gous for the C677T mutation of the methylenetetrahydrofolate reductase gene and heterozygous for the mutation of the prothrombin G20210A gene. No other cause of cerebral infarction was found in the patient. PMID:25509247

  20. Chromogenic assay for the prothrombin activator ecarin from the venom of the saw-scaled viper (Echis carinatus).

    PubMed

    Stocker, K; Fischer, H; Brogli, M

    1986-01-01

    Ecarin, by limited proteolysis and subsequent autocatalytic reactions, causes the conversion of prothrombin into three products with amidolytic activity: meizothrombin, meizothrombin 1 and lpha-thrombin. Ecarin action may be abolished by ethylenediaminetetraacetic acid and the activity of alpha-thrombin can, with a high degree of selectivity, be inhibited by heparin. Thus, ecarin potency may be assayed by measuring the meizothrombin activity generated by ecarin action on human plasma in the presence of heparin. The chromogenic substrate Tosyl-glycyl-L-prolyl-L-arginine-p-nitroanilide (Chromozym TH) is used in this assay. PMID:3082039

  1. Biological regulation of receptor-hormone complex concentrations in relation to dose-response assessments for endocrine-active compounds.

    PubMed

    Andersen, M E; Barton, H A

    1999-03-01

    Some endocrine-active compounds (EACs) act as agonists or antagonists of specific hormones and may interfere with cellular control processes that regulate gene transcription. Many mechanisms controlling gene expression are universal to organisms ranging from unicellular bacteria to more complex plants and animals. One mechanism, coordinated control of batteries of gene products, is critical in adaptation of bacteria to new environments and for development and tissue differentiation in multi-cellular organisms. To coordinately activate sets of genes, all living organisms have devised molecular modules to permit transitions, or switching, between different functional states over a small range of hormone concentration, and other modules to stabilize the new state through homeostatic interactions. Both switching and homeostasis are regulated by controlling concentrations of hormone-receptor complexes. Molecular control processes for switching and homeostasis are inherently nonlinear and often utilize autoregulatory feedback loops. Among the biological processes contributing to switching phenomena are receptor autoinduction, induction of enzymes for ligand synthesis, mRNA stabilization/activation, and receptor polymerization. This paper discusses a variety of molecular switches found in animal species, devises simple quantitative models illustrating roles of specific molecular interactions in creating switching modules, and outlines the impact of these switching processes and other feedback loops for risk assessments with EACs. Quantitative simulation modeling of these switching mechanisms made it apparent that highly nonlinear dose-response curves for hormones and EACs readily arise from interactions of several linear processes acting in concert on a common control point. These nonlinear mechanisms involve amplification of response, rather than multimeric molecular interactions as in conventional Hill relationships. PMID:10330682

  2. Prospective evaluation of the thrombotic risk in children with acute lymphoblastic leukemia carrying the MTHFR TT 677 genotype, the prothrombin G20210A variant, and further prothrombotic risk factors.

    PubMed

    Nowak-Göttl, U; Wermes, C; Junker, R; Koch, H G; Schobess, R; Fleischhack, G; Schwabe, D; Ehrenforth, S

    1999-03-01

    The reported incidence of thromboembolism in children with acute lymphoblastic leukemia (ALL) treated with L-asparaginase, vincristine, and prednisone varies from 2.4% to 11.5%. The present study was designed to prospectively evaluate the role of the TT677 methylenetetrahydrofolate reductase (MTHFR) genotype, the prothrombin G20210A mutation, the factor V G1691A mutation, deficiencies of protein C, protein S, antithrombin, and increased lipoprotein (a) concentrations in leukemic children treated according to the ALL-Berlin-Frankfurt-Muenster (BFM) 90/95 study protocols with respect to the onset of vascular events. Three hundred and one consecutive leukemic children were enrolled in this study. Fifty-five of these 301 subjects investigated had one established single prothrombotic risk factor: 20 children showed the TT677 MTHFR genotype; 5 showed the heterozygous prothrombin G20210A variant; 11 were carriers of the factor V G1691A mutation (heterozygous, n = 10; homozygous, n = 1); 4 showed familial protein C, 4 protein S, and 2 antithrombin type I deficiency; 9 patients were suffering from familially increased lipoprotein (a) [Lp(a)] concentrations (>30 mg/dL). In addition, combined prothrombotic defects were found in a further 10 patients: the FV mutation was combined with the prothrombin G20210A variant (n = 1), increased Lp(a) (n = 3), protein C deficiency (n = 1), and homozygosity for the C677T MTHFR gene mutation (n = 1). Lp(a) was combined with protein C deficiency (n = 2) and the MTHFR TT 677 genotype (n = 2). Two hundred eighty-nine of the 301 patients were available for thrombosis-free survival analysis. In 32 (11%) of these 289 patients venous thromboembolism occurred. The overall thrombosis-free survival in patients with at least one prothrombotic defect was significantly reduced compared with patients without a prothrombotic defect within the hemostatic system (P <.0001). In addition, a clear-cut positive correlation (P <.0001) was found between

  3. Analysis of ambient SO 2 concentrations and winds in the complex surroundings of a thermal power plant

    NASA Astrophysics Data System (ADS)

    Mlakar, P.

    2004-11-01

    in order to find the correlation between winds and pollutant concentrations. The analyses made provide a better insight into air pollution over complex terrain.

  4. Characterisation of sub-micron particle number concentrations and formation events in the western Bushveld Igeneous Complex, South Africa

    NASA Astrophysics Data System (ADS)

    Hirsikko, A.; Vakkari, V.; Tiitta, P.; Manninen, H. E.; Gagné, S.; Laakso, H.; Kulmala, M.; Mirme, A.; Mirme, S.; Mabaso, D.; Beukes, J. P.; Laakso, L.

    2012-01-01

    South Africa holds significant mineral resources, with a substantial fraction of these reserves occurring in a large geological structure termed the Bushveld Igeneous Complex (BIC). The majority of the world's platinum group metals (PGMs) and chromium originate from the BIC. Considering the importance of PGMs in the manufacturing of automotive catalytic converters, as well as the relatively poor current state of air quality and the general lack of atmospheric research in the BIC, atmospheric related research in this geographical area is of local (South African) and of international interest. The western limb of the BIC is the most exploited, with at least eleven pyrometallurgical smelters occurring within a 55 km radius. Due to the lure of employment in the industrialised BIC, the area is populated by informal, semi-formal and formal residential developments. In order to investigate the characteristics and processes affecting sub-micron particle number concentrations and formation events, air ion and aerosol particle size distribution and concentration measurements were conducted for over two years at Marikana in the heart of the western BIC. Our results indicated that high amounts of Aitken and accumulation mode particles originated from domestic burning for heating and cooking in the morning and evening, while during daytime SO2-based nucleation (from industrial emissions) was the most probable source for large number concentrations of nucleation and Aitken mode particles. Nucleation event day frequency was extremely high, i.e. 86% of the analysed days, which to the knowledge of the authors is the highest frequency ever reported. Secondary particle formation was influenced both by local pollution sources and regional ambient conditions. Therefore, our observation of the annual cycle and magnitude of the particle formation and growth rates during nucleation events were similar to the results from a semi-clean savannah site in South Africa.

  5. Inhibition of prothrombin kringle-2-induced inflammation by minocycline protects dopaminergic neurons in the substantia nigra in vivo.

    PubMed

    Nam, Jin Han; Leem, Eunju; Jeon, Min-Tae; Kim, Young-Je; Jung, Un Ju; Choi, Myung-Sook; Maeng, Sungho; Jin, Byung Kwan; Kim, Sang Ryong

    2014-05-01

    Prothrombin kringle-2 (pKr-2), a domain of prothrombin, can cause the degeneration of mesencephalic dopaminergic neurons through microglial activation. However, the chemical products that inhibit pKr-2-induced inflammatory activities in the brain are still not well known. The present study investigated whether minocycline, a semisynthetic tetracycline derivative, could inhibit pKr-2-induced microglial activation and prevent the loss of nigral dopaminergic (DA) neurons in vivo. To address this question, rats were administered a unilateral injection of pKr-2 in the substantia nigra in the presence or absence of minocycline. Our results show that pKr-2 induces the production of proinflammatory cytokines, such as tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), and inducible nitric oxide synthase from the activated microglia. In parallel, 7 days after pKr-2 injection, tyrosine hydroxylase immunocytochemical analysis and western blot analysis showed a significant loss of nigral DA neurons. This neurotoxicity was antagonized by minocycline and the observed neuroprotective effects were associated with the ability of minocycline to suppress the expression of tumor necrosis factor-α, interleukin-1β, and nitric oxide synthase. These results suggest that minocycline may be promising as a potential therapeutic agent for the prevention of DA neuronal degeneration associated with pKr-2-induced microglial activation. PMID:24488033

  6. Capsaicin exposure elicits complex airway defensive motor patterns in normal humans in a concentration-dependent manner.

    PubMed

    Vovk, A; Bolser, D C; Hey, J A; Danzig, M; Vickroy, T; Berry, R; Martin, A D; Davenport, P W

    2007-01-01

    The airway defensive response to tussive agents, such as capsaicin, is frequently assessed by counting the number of cough sounds, or expulsive events. This method does not identify or differentiate important respiratory events that occur in the respiratory muscles and lungs, which are critical in assessing airway defensive responses. The purpose of this study was to characterize the airway defensive behaviours (cough and expiration reflex) to capsaicin exposure in humans. We observed complex motor behaviours in response to capsaicin exposure. These behaviours were defined as cough reacceleration (CRn) and expiration reflex (ERn), where n is the number of expulsive events with and without a preceding inspiratory phase, respectively. Airway defensive responses were defined in terms of frequency (number of expulsive events), strength (activation of abdominal muscles) and behaviour type (CRn vs. ERn). Thirty-six subjects (15 females, 24+/-4 yr) were instrumented with EMG electrodes placed over the rectus abdominis (RA), external abdominal oblique (EO) and the 8th intercostal space (IC8). A custom-designed mouth pneumotachograph was used to assess the airflow acceleration, plateau velocity and phase duration of the expulsive phase. Subjects inhaled seven concentrations of capsaicin (5-200 microM) in a randomized block order. The total number of expulsive events (frequency) and the sum of integrated EMG for the IC8, RA and EO (strength) increased in a curvilinear fashion. Differentiating the airway defense responses into type demonstrated predominately CR1 and CR2 (i.e. inspiration followed by one and two expulsive events, respectively) with very few ER's at <50 microM capsaicin. At higher concentrations (>50 microM) ER's with one or more expulsive events (ER1) appeared, and the number of CR's with three or more expulsive events (CR3) increased. The decrease in EMG activation and airflow measurements with each successive expulsive event suggests a decline in power and

  7. Photochemical Reduction of Low Concentrations of CO2 in a Porous Coordination Polymer with a Ruthenium(II)-CO Complex.

    PubMed

    Kajiwara, Takashi; Fujii, Machiko; Tsujimoto, Masahiko; Kobayashi, Katsuaki; Higuchi, Masakazu; Tanaka, Koji; Kitagawa, Susumu

    2016-02-18

    Direct use of low pressures of CO2 as a C1 source without concentration from gas mixtures is of great interest from an energy-saving viewpoint. Porous heterogeneous catalysts containing both adsorption and catalytically active sites are promising candidates for such applications. Here, we report a porous coordination polymer (PCP)-based catalyst, PCP-Ru(II) composite, bearing a Ru(II) -CO complex active for CO2 reduction. The PCP-Ru(II) composite showed improved CO2 adsorption behavior at ambient temperature. In the photochemical reduction of CO2 the PCP-Ru(II) composite produced CO, HCOOH, and H2 . Catalytic activity was comparable with the corresponding homogeneous Ru(II) catalyst and ranks among the highest of known PCP-based catalysts. Furthermore, catalytic activity was maintained even under a 5 % CO2 /Ar gas mixture, revealing a synergistic effect between the adsorption and catalytically active sites within the PCP-Ru(II) composite. PMID:26800222

  8. Cytosolic calcium concentration is reduced by photolysis of a nitrosyl ruthenium complex in vascular smooth muscle cells.

    PubMed

    Lunardi, C N; Cacciari, A L; Silva, R S; Bendhack, L M

    2006-11-01

    The effect of the NO donors cis-[RuCl(bpy)(2)(NO)](PF(6)) (RUNOCL) and sodium nitroprusside (SNP) on the cytosolic Ca(2+) concentration ([Ca(2+)](c)) was studied in cells isolated from the rat aorta smooth muscle of cells isolated from the rat aorta smooth muscle. SNP is a metal nitrosyl complex made up of iron, cyanide groups, and a nitro moiety; the RUNOCL complex is made up of ruthenium and bipyridine ligands, with chloride and nitrosyl groups in the ruthenium axial positions. Rat aorta smooth muscle cells were loaded with fluo-3 acetoxymethyl ester (Fluo-3 AM) and imaged by a confocal scanning laser microscope excited with the 488 nm line of the argon ion laser. Fluorescence emission was measured at 510 nm. One of the NO donors, RUNOCL (100 micromol/L) or SNP (100 micromol/L), was then added to the cell chamber and the fluorescent intensity percentage (%IF) was measured after 240 s. RUNOCL reduced the %IF to 60.0+/-10.0% of the initial value. After treatment with the soluble guanylyl cyclase inhibitor 1H-[1,2,4]oxadiazole[4,3-a]quinoxalin-1-one (ODQ) (10 micromol/L), the measurement of %IF was 81.0+/-5.0% (n=4). In the presence of tetraethylammonium (TEA) (1 mmol/L) the %IF was 79.0+/-6.4% (n=4). A combination of ODQ and TEA increased the %IF to 97.0+/-3.5% (n=4). As for SNP, it reduced the %IF to 81.4+/-4.7% (n=4), but this effect was inhibited by ODQ (%IF 94.0+/-3.6%; n=4) and TEA (%IF 88.0+/-2.1%; n=4). The combination of ODQ and TEA increased (%IF 92.0+/-2.8%; n=4). Taken together, these results indicate that both the new NO donor RUNOCL and SNP reduce [Ca(2+)](c). Our data also give evidence that soluble guanylyl cyclase and K(+) channels sensitive to TEA are involved in the mechanisms responsible for the reduction in [Ca(2+)](c) of the rat aorta smooth muscle cells. PMID:16564714

  9. Risk of Budd-Chiari Syndrome Associated with Factor V Leiden and G20210A Prothrombin Mutation: A Meta-Analysis

    PubMed Central

    Sun, Guixiang; Gao, Xiuyin; Wang, Hui; Yan, Wenjun; Xu, Hao; Zu, Maoheng; Ma, He; Wang, Wei; Lu, Zhaojun

    2014-01-01

    Background Various studies have demonstrated that factor V Leiden (FVL) and G20210A prothrombin mutation contribute to the risk of Budd-Chiari syndrome (BCS), while other studies provided conflicting findings. In order to derive more precise estimations of the relationships, a meta-analysis was performed. Methods Eligible articles were identified through search of databases including Pubmed, Chinese Biomedical Database (CBM, Chinese), and Chinese National Knowledge Infrastructure (CNKI, Chinese). Odd ratios (ORs) with 95% confidence intervals (CIs) were calculated using random- or fixed- model. Results Finally, twelve studies were included for FVL and nine studies were included for G20210A prothrombin mutation. With respect to FVL, significantly increased BCS risk was found in the overall population (OR = 6.29, 95%CI = 4.23–9.36). Subgroup analyses suggested that FVL was associated with an increased risk of BCS in the population with high background mutation prevalence (>1% in the normal population). No significant association was found between BCS and G20210A prothrombin mutation (OR = 1.78, 95%CI = 0.77–4.11). Conclusion The presence of FVL should be evaluated in patients with BCS. Conversely, G20210A prothrombin mutation is not significantly associated with risk of BCS. Large-scale well designed studies are necessary to be conducted to further confirm or refute the observed association. PMID:24755609

  10. Cloning of a prothrombin activator-like metalloproteinase from the West African saw-scaled viper, Echis ocellatus.

    PubMed

    Hasson, S S; Theakston, R D G; Harrison, R A

    2003-11-01

    Systemic envenoming by the saw-scaled viper, Echis ocellatus, is responsible for more deaths than any other snake in West Africa. Despite its medical importance, there have been few investigations into the toxin composition of the venom of this viper. Here we describe the isolation of E. ocellatus venom gland cDNAs encoding a protein of 514 amino acids that showed 91% sequence similarity to Ecarin, a prothrombin-activating metalloproteinase from the venom of the East African viper, E. pyramidum leakeyi, that induces severe consumption coagulopathy. Structural similarities between the E. ocellatus metalloproteinase and analogues in venoms of related vipers suggest that antibodies raised to phylogenetically conserved E. ocellatus metalloproteinase domains may have potential for cross-specific and cross-generic neutralisation of analogous venom toxins. PMID:14602118

  11. Upregulation of des-gamma-carboxy-prothrombin after portal vein embolization in a cirrhotic patient with hepatocellular carcinoma.

    PubMed

    Sohda, Tetsuro; Iwata, Kaoru; Anan, Akira; Kunimoto, Hideo; Yotsumoto, Kaoru; Yokoyama, Keiji; Morihara, Daisuke; Takeyama, Yasuaki; Shakado, Satoshi; Osame, Akinobu; Kora, Shinichi; Ohishi, Jun; Yamauchi, Yasushi; Noritomi, Tomoaki; Yoshimitsu, Kengo; Yamashita, Yuichi; Sakisaka, Shotaro

    2015-10-01

    A 73-year-old female with hepatocellular carcinoma (HCC) received percutaneous transhepatic portal vein embolization (PTPE) before extensive right lobe hepatectomy. Serum levels of des-gamma-carboxy-prothrombin (DCP) were increased and remained at a high level until hepatectomy. Immunohistochemical examination revealed that an increased expression of DCP was demonstrated not only in HCC tissues, but also in the non-cancerous liver of the right lobe, where portal blood flow was blocked off as a result of PTPE. The serum level of DCP is known to be greatly increased in patients with HCC accompanied by portal vein invasion. We speculate that this increased DCP level is caused by both increased DCP production in HCC tissue and the surrounding non-cancerous liver, where portal flow is blocked off as a result of portal invasion by HCC. PMID:26374567

  12. Prothrombin kringle-2 induces death of mesencephalic dopaminergic neurons in vivo and in vitro via microglial activation.

    PubMed

    Kim, Sang Ryong; Chung, Eun Sook; Bok, Eugene; Baik, Hyung Hwan; Chung, Young Cheul; Won, So Yoon; Joe, Eunhye; Kim, Tae Hyong; Kim, Soung Soo; Jin, Min Young; Choi, Sang Ho; Jin, Byung Kwan

    2010-05-15

    We have shown that prothrombin kringle-2 (pKr-2), a domain of human prothrombin distinct from thrombin could activate cultured rat brain microglia in vitro. However, little is known whether pKr-2-induced microglial activation could cause neurotoxicity on dopaminergic (DA) neurons in vivo. To address this question, pKr-2 was injected into the rat substantia nigra (SN). Tyrosine hydroxylase (TH) immunohistochemistry experiments demonstrate significant loss of DA neurons seven days after injection of pKr-2. In parallel, pKr-2-activated microglia were detected in the SN with OX-42 and OX-6 immunohistochemistry. Reverse transcription PCR and double-label immunohistochemistry revealed that activated microglia in vivo exhibit early and transient expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2) and several proinflammatory cytokines. The pKr-2-induced loss of SN DA neurons was partially inhibited by the NOS inhibitor N(G)-nitro-L-arginine methyl ester hydrochloride, and the COX-2 inhibitor DuP-697. Extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase and p38 mitogen-activated protein kinase were activated in the SN as early as 1 hr after pKr-2 injection, and localized within microglia. Inhibition of these kinases led to attenuation of mRNA expression of iNOS, COX-2 and several proinflammatory cytokines, and rescue of DA neurons in the SN. Intriguingly, following treatment with pKr-2 in vitro, neurotoxicity was detected exclusively in co-cultures of mesencephalic neurons and microglia, but not microglia-free neuron-enriched mesencephalic cultures, indicating that microglia are required for pKr-2 neurotoxicity. Our results strongly suggest that microglia activated by endogenous compound(s), such as pKr-2, are implicated in the DA neuronal cell death in the SN. PMID:20025058

  13. Regulation of expression of venom toxins: silencing of prothrombin activator trocarin D by AG-rich motifs.

    PubMed

    Han, Summer Xia; Kwong, Shiyang; Ge, Ruowen; Kolatkar, Prasanna R; Woods, Anthony E; Blanchet, Guillaume; Kini, R Manjunatha

    2016-06-01

    Trocarin D (TroD), a venom prothrombin activator from Tropidechis carinatus, shares similar structure and function with blood coagulation factor Xa [Tropidechis carinatus FX (TrFX) a]. Their distinct physiologic roles are due to their distinct expression patterns. The genes of TroD and TrFX are highly similar, except for promoter and intron 1, indicating that TroD has probably evolved by duplication of FX, the plasma counterpart. The promoter insertion in TroD accounts for the elevated but not venom gland-specific expression. Here we examined the roles of 3 insertions and 2 deletions in intron 1 of TroD in the regulation of expression using luciferase as a reporter. By systematic deletions, we showed that a 209 bp region within the second insertion silences expression in mammalian and unmilked venom gland cells. Through bioinformatics analysis, we identified 5 AG-rich motifs in this region. All except the 5th motif are important for silencing function. YY1, Sp3 and HMGB2 were identified to bind these AG-rich motifs and silence gene expression in mammalian cells. Similar AG-rich motif clusters are also found in other toxin genes but not in their physiologic counterparts. Thus, AG-rich motifs contribute to regulation of expression of TroD, and probably other toxin genes.-Han, S. X., Kwong, S., Ge, R., Kolatkar, P. R., Woods, A. E., Blanchet, G., Kini, R. M. Regulation of expression of venom toxins: silencing of prothrombin activator trocarin D by AG-rich motifs. PMID:26985007

  14. Classical Nuclear Hormone Receptor Activity as a Mediator of Complex Concentration Response Relationships for Endocrine Active Compounds

    PubMed Central

    Cookman, Clifford J.; Belcher, Scott M.

    2014-01-01

    Nonmonotonic concentration response relationships are frequently observed for endocrine active ligands that act via nuclear receptors. The curve of best fit for nonmonotonic concentration response relationships are often inverted U-shaped with effects at intermediate concentrations that are different from effects at higher or lower concentrations. Cytotoxicity is a major mode of action responsible for inverted U-shaped concentration response relationships. However, evidence suggests that ligand selectivity, activation of multiple molecular targets, concerted regulation of multiple opposing endpoints, and multiple ligand binding sites within nuclear receptors also contribute to nonmonotonic concentration response relationships of endocrine active ligands. This review reports the current understanding of mechanisms involved in classical nuclear receptor mediated nonmonotonic concentration response relationships with a focus on studies published between 2012 and 2014. PMID:25299165

  15. Uranium reduction by Shewanella oneidensis MR-1 as a function of NaHCO3 concentration: surface complexation control of reduction kinetics.

    PubMed

    Sheng, Ling; Fein, Jeremy B

    2014-04-01

    It is crucial to determine the controls on the kinetics of U(VI) bioreduction in order to understand and model the fate and mobility of U in groundwater systems and also to enhance the effectiveness of U bioremediation strategies. In this study, we measured the rate of U(VI) reduction by Shewanella oneidensis strain MR-1 as function of NaHCO3 concentration. The experiments demonstrate that increasing concentrations of NaHCO3 in the system lead to slower U(VI) reduction kinetics. The NaHCO3 concentration also strongly affects the speciation of U(VI) on the bacterial cell envelope. We used a thermodynamic surface complexation modeling approach to determine the speciation and concentration of U(VI) adsorbed onto the bacteria as a function of the NaHCO3 concentration in the experimental systems. We observed a strong positive correlation between the measured U(VI) reduction rates and the calculated total concentration of U(VI) surface complexes formed on the bacterial cell envelope. This positive correlation indicates that the speciation and concentration of U(VI) adsorbed on the bacterial cell envelope control the kinetics of U(VI) bioreduction under the experimental conditions. The results of this study serve as a basis for developing speciation-based kinetic rate laws for enzymatic reduction of U(VI) by bacteria. PMID:24576101

  16. ANNUAL PROGRESS REPORT. THE AQUEOUS THERMODYNAMICS AND COMPLEXATION REACTIONS OF ANIONIC SILICA SPECIES TO HIGH CONCENTRATION: EFFECTS ON NEUTRALIZATION OF LEAKED TANK WASTES AND MIGRATION OF RADIONUC

    EPA Science Inventory

    In this project, we are determining the aqueous thermodynamics and speciation of dissolved silica and silica-radionuclide complexes to high silica concentration using a combination of 1) studies of chemical species structure and composition (via nuclear magnetic resonance and, wh...

  17. New procyanidin B3-human salivary protein complexes by mass spectrometry. Effect of salivary protein profile, tannin concentration, and time stability.

    PubMed

    Perez-Gregorio, Maria Rosa; Mateus, Nuno; De Freitas, Victor

    2014-10-15

    Several factors could influence the tannin-protein interaction such as the human salivary protein profile, the tannin tested, and the tannin/protein ratio. The goal of this study aims to study the effect of different salivas (A, B, and C) and different tannin concentrations (0.5 and 1 mg/mL) on the interaction process as well as the complex's stability over time. This study is focused on the identification of new procyanidin B3-human salivary protein complexes. Thus, 48 major B3-human salivary protein aggregates were identified regardless of the saliva and tannin concentration tested. A higher number of aggregates was found at lower tannin concentration. Moreover, the number of protein moieties involved in the aggregation process was higher when the tannin concentration was also higher. The selectivity of the different groups of proteins to bind tannin was also confirmed. It was also verified that the B3-human salivary protein complexes formed evolved over time. PMID:25248720

  18. Changes of nitrate concentrations in surface waters influenced by land use in the crystalline complex of the Czech Republic

    NASA Astrophysics Data System (ADS)

    Kvítek, T.; Žlábek, P.; Bystřický, V.; Fučík, P.; Lexa, M.; Gergel, J.; Novák, P.; Ondr, P.

    Changes in nitrate pollution in surface waters brought by the construction of tile drainage systems and by conversion of cultivated land to grassland (followed by decrease in fertilizer use) in two districts were examined. The goal was to find out how nitrate concentrations have responded to changes in agricultural management. There were no major changes in land use in the Pelhrimov district after 1990, apart from decrease in mineral fertilizer use. In the Cesky Krumlov district, permanent grassland area increased by 55% (from 228.9 km 2 to 353.3 km 2) and by 241% (from 5.4 km 2 to 13 km 2) in the catchments investigated between 1990 and 2000 followed by reduction in use of fertilizers. In these two districts, 31 small catchments where long-term, or repeated, nitrate concentration monitoring was carried out between 1986 and 2005, were analyzed. Trend, regression and factor analyses were conducted on changes in nitrate concentrations, and to assess the impact of several factors on nitrate concentrations in water before and after conversion to grassland. Over the monitoring period 1986-2005, there was a significant decreasing linear trend in N-NO3- concentration in surface waters in all catchments in the Cesky Krumlov district. In the Pelhrimov district 3 of 23 catchments showed a significant decreasing trend in nitrate concentrations and 2 a significant increasing trend despite a decrease in mineral nitrogen consumption. The most important environmental factor affecting nitrate pollution was the proportion of ploughed land in the catchment. The greater the share of ploughed land in the catchment, the greater the nitrate contamination of surface water. The proportion of drained land in the catchment after grassing has no markedly influence on nitrate nitrogen concentration.

  19. Airborne pollutant characteristics in an urban, industrial and agricultural complex metroplex with high emission loading and ammonia concentration.

    PubMed

    Tsai, Jiun-Horng; Chang, Li-Peng; Chiang, Hung-Lung

    2014-10-01

    The size distribution of particulate mass and water-soluble ionic constituents and their gaseous precursors was investigated in a subtropical area, southern Taiwan. Field sampling and chemical analysis of particulate matter (PM) were conducted using a Micro Orifice Uniform Deposition Impactor (MOUDI) and a Nano-MOUDI, and gaseous pollutants were determined by a denuder-filter pack system. PM size mass distribution, mass concentration and ionic species concentration were measured during the day and at night in the winter and summer. Average PM concentrations in the winter were as high as 132 ± 42 μg/m(3), and PM mass concentrations in the summer were as low as 38 ± 19 μg/m(3). Generally, PM concentration was 111 ± 60 μg/m(3) at night, which was 20% higher than that in the daytime. The size-segregated mass distribution of PM mass concentration was over 85% in the 0.1-3.2 μm range. Ammonium, nitrate, and sulfate were the dominant water-soluble ionic species in PM, contributing 34%-48% of PM mass. High ammonia (12.9-49 μg/m(3)) and SO2 (2.6-27 μg/m(3)) were observed in the gas precursors. The molar ratio [Formula: see text] was 3.18 ± 1.20 at PM1.0, which indicated that the PM was rich in ammonium. Therefore, the excess ammonium could neutralize nitrate to form ammonium nitrate, after the more stable ammonium sulfate and ammonium bisulfate formation. PMID:25037046

  20. Dynamic Antibody Specificities and Virion Concentrations in Circulating Immune Complexes in Acute to Chronic HIV-1 Infection ▿ †

    PubMed Central

    Liu, Pinghuang; Overman, R. Glenn; Yates, Nicole L.; Alam, S. Munir; Vandergrift, Nathan; Chen, Yue; Graw, Frederik; Freel, Stephanie A.; Kappes, John C.; Ochsenbauer, Christina; Montefiori, David C.; Gao, Feng; Perelson, Alan S.; Cohen, Myron S.; Haynes, Barton F.; Tomaras, Georgia D.

    2011-01-01

    Understanding the interactions between human immunodeficiency virus type 1 (HIV-1) virions and antibodies (Ab) produced during acute HIV-1 infection (AHI) is critical for defining antibody antiviral capabilities. Antibodies that bind virions may prevent transmission by neutralization of virus or mechanically prevent HIV-1 migration through mucosal layers. In this study, we quantified circulating HIV-1 virion-immune complexes (ICs), present in approximately 90% of AHI subjects, and compared the levels and antibody specificity to those in chronic infection. Circulating HIV-1 virions coated with IgG (immune complexes) were in significantly lower levels relative to the viral load in acute infection than in chronic HIV-1 infection. The specificities of the antibodies in the immune complexes differed between acute and chronic infection (anti-gp41 Ab in acute infection and anti-gp120 in chronic infection), potentially suggesting different roles in immunopathogenesis for complexes arising at different stages of infection. We also determined the ability of circulating IgG from AHI to bind infectious versus noninfectious virions. Similar to a nonneutralizing anti-gp41 monoclonal antibody (MAb), purified plasma IgG from acute HIV-1 subjects bound both infectious and noninfectious virions. This was in contrast to the neutralizing antibody 2G12 MAb that bound predominantly infectious virions. Moreover, the initial antibody response captured acute HIV-1 virions without selection for different HIV-1 envelope sequences. In total, this study demonstrates that the composition of immune complexes are dynamic over the course of HIV-1 infection and are comprised initially of antibodies that nonselectively opsonize both infectious and noninfectious virions, likely contributing to the lack of efficacy of the antibody response during acute infection. PMID:21865397

  1. The Fragment 1 Region of Prothrombin Facilitates the Favored Binding of Fragment 12 to Zymogen and Enforces Zymogen-like Character in the Proteinase.

    PubMed

    Bradford, Harlan N; Krishnaswamy, Sriram

    2016-05-20

    Thrombin is produced from the C-terminal half of prothrombin following its proteolytic activation. The N-terminal half, released as the propiece Fragment 12 (F12), is composed of an N-terminal γ-carboxyglutamate domain (Gla) followed by two kringles (K1 and K2). The propiece plays essential roles in regulating prothrombin activation and proteinase function. The latter results from the ability of F12 to reversibly bind to the (pro)catalytic domain through K2 with high affinity and highly favorable thermodynamic constants when it is a zymogen in comparison to proteinase. Such discrimination is lost for K2 binding after proteolytic removal of the N-terminal Gla-K1 region of F12. The Ca(2+)-stabilized structure of the Gla domain is not required for F12 to bind the zymogen form more favorably. Enhanced binding to zymogen versus proteinase correlates with the ability of the propiece to enforce zymogen-like character in the proteinase. This is evident in variants of meizothrombin, an intermediate of prothrombin activation that contains the propiece covalently attached. This phenomenon is also independent of the Gla domain. Thus, the presence of K1 in covalent linkage with K2 in the propiece governs the ability of K2 to bind the (pro)catalytic domain in favor of zymogen, thereby enforcing zymogen-like character in the proteinase. PMID:27013660

  2. Structure of the propeptide of prothrombin containing the. gamma. -carboxylation recognition site determined by two-dimensional NMR spectroscopy

    SciTech Connect

    Sanford, D.G.; Sudmeier, J.L.; Bachovchin, W.W.; Kanagy, C.; Furie, B.C.; Furie, B. )

    1991-10-15

    The propeptides of the vitamin K dependent blood clotting and regulatory proteins contain a {gamma}-carboxylation recognition site that directs precursor forms of these proteins for posttranslational {gamma}-carboxylation. Peptides corresponding to the propeptide of prothrombin were synthesized and examined by circular dichroism (CD) and nuclear magnetic resonance spectroscopy (NMR). CD spectra indicate that these peptides have little or no secondary structure in aqueous solutions but that the addition of trifluoroethanol induces or stabilizes a structure containing {alpha}-helical character. The maximum helical content occurs at 35-40% trifluoroethanol. This trifluoroethanol-stabilized structure was solved by two-dimensional NMR spectroscopy. The NMR results demonstrate that residues {minus}13 to {minus}3 form an amphipathic {alpha}-helix. NMR spectra indicate that a similar structure is present at 5C, in the absence of trifluoroethanol. Of the residues previously implicated in defining the {gamma}-carboxylation recognition site, four residues ({minus}18, {minus}17, {minus}16, and {minus}15) are adjacent to the helical region and one residue ({minus}10) is located within the helix. The potential role of the amphipathic {alpha}-helix in the {gamma}-carboxylation recognition site is discussed.

  3. Structure of the propeptide of prothrombin containing the gamma-carboxylation recognition site determined by two-dimensional NMR spectroscopy.

    PubMed

    Sanford, D G; Kanagy, C; Sudmeier, J L; Furie, B C; Furie, B; Bachovchin, W W

    1991-10-15

    The propeptides of the vitamin K dependent blood clotting and regulatory proteins contain a gamma-carboxylation recognition site that directs precursor forms of these proteins for posttranslational gamma-carboxylation. Peptides corresponding to the propeptide of prothrombin were synthesized and examined by circular dichroism (CD) and nuclear magnetic resonance spectroscopy (NMR). CD spectra indicate that these peptides have little or no secondary structure in aqueous solutions but that the addition of trifluoroethanol induces or stabilizes a structure containing alpha-helical character. The maximum helical content occurs at 35-40% trifluoroethanol. This trifluoroethanol-stabilized structure was solved by two-dimensional NMR spectroscopy. The NMR results demonstrate that residues -13 to -3 form an amphipathic alpha-helix. NMR spectra indicate that a similar structure is present at 5 degrees C, in the absence of trifluoroethanol. Of the residues previously implicated in defining the gamma-carboxylation recognition site, four residues (-18, -17, -16, and -15) are adjacent to the helical region and one residue (-10) is located within the helix. The potential role of the amphipathic alpha-helix in the gamma-carboxylation recognition site is discussed. PMID:1911775

  4. Anti-inflammatory effect of a human prothrombin fragment-2-derived peptide, NSA9, in EOC2 microglia

    SciTech Connect

    Kim, Ji Yeon; Kim, Tae Hyong; Kim, Soung Soo

    2008-04-11

    Pro-inflammatory mediators, such as nitric oxide (NO), prostaglandin E{sub 2} (PGE{sub 2}), and several cytokines (tumor necrosis factor (TNF)-{alpha}, interleukin (IL)-1{beta}, and IL-6) are responsible for central nervous system (CNS) injuries that include ischemia, Alzheimer's disease, and neural death. Inhibition of these pro-inflammatory mediators would be an effective therapy to reduce the progression of neurodegenerative diseases. In this study, we examined the anti-inflammatory effects of a human prothrombin fragment-2-derived peptide, NSA9 (NSAVQLVEN), on the production of pro-inflammatory mediators in lipopolysaccharide (LPS)-activated brain microglia. NSA9 significantly inhibited the release of NO, PGE{sub 2}, and pro-inflammatory cytokines in a dose-dependent manner. Furthermore, NSA9 reduced the expression of inducible NO synthase (iNOS) and cyclooxygenase (COX)-2 mRNA and protein, which control the production of NO and PGE{sub 2}, respectively. Moreover, NSA9 suppressed the LPS-induced nuclear translocation and activation of nuclear factor-{kappa}B (NF-{kappa}B). These results suggest that NSA9 strongly inhibits the pro-inflammatory responses of microglia through the modulation of NF-{kappa}B activity.

  5. Diagnostic performance of des-γ-carboxy prothrombin (DCP) for hepatocellular carcinoma: a bivariate meta-analysis.

    PubMed

    Gao, P; Li, M; Tian, Q B; Liu, Dian-Wu

    2012-01-01

    Serum markers are needed to be developed to specifically diagnose Hepatocellular carcinoma (HCC). Des-γ-carboxy prothrombin (DCP) is a promising tool with limited expense and widely accessibility, but the reported results have been controversial. In order to review the performance of DCP for the diagnosis of HCC, the meta-analysis was performed. After a systematic review of relevant studies, the sensitivity, specificity, positive and negative likelihood ratios (PLR and NLR, respectively) were pooled using a bivariate meta-analysis. Potential between-study heterogeneity was explored by meta-regression model. The post-test probability and the likelihood ratio scattergram to evaluate clinical usefulness were calculated. Based on literature review of 20 publications, the overall sensitivity, specificity, PLR and NLR of DCP for the detection of HCC were 67% (95%CI, 58%-74%), 92% (95%CI, 88%-94%), 7.9 (95%CI, 5.6-11.2) and 0.36 (95%CI, 0.29-0.46), respectively. The area under the bivariate summary receiving operating characteristics curve was 0.89 (95%CI, 0.85-0.92). Significant heterogeneity was present. In conclusion, the major role of DCP is the moderate confirmation of HCC. More prospective studies of DCP are needed in future. PMID:22248272

  6. Autosomal-dominant inheritance of the prothrombin gene mutation in a Puerto Rican family: A case study.

    PubMed

    Morales-Borges, Raúl H

    2012-12-01

    Splenic infarction is rare and the prothrombin gene mutation (PGM) is not commonly observed in Puerto Rico. PGM is present in 1% of the general population, and in 7% of the people with deep venous thrombosis (DVT); it is found in up to 40% of patients with splenic-portal-mesenteric thrombosis. Our study has identified a Puerto Rican family of four generations whose members all have inherited PGM in an autosomal dominant manner. The eldest member of the family, an 82-year-old male, presented with DVT of the lower extremity. The man's 62-year-old daughter had suffered a splenic infarction; his 37-year-old grandson presented with superficial and deep vein thrombosis (SDVT), and his great-grandson of 8 years was asymptomatic at the time of the report. This is the second report of PGM as the cause of a hypercoagulable state and the first reported PGM-related splenic infarction in Puerto Rico. We need to test for genetic hypercoagulable states in the members of Puerto Rican families with thromboembolism. Once testing has revealed the existence of such states in a given family, it is important that the family members receive genetic counseling. PMID:23844473

  7. Evaluation of Prothrombin Time and Activated Partial Thromboplastin Time in Hypertensive Patients Attending a Tertiary Hospital in Calabar, Nigeria

    PubMed Central

    Nnenna Adaeze, Nnamani; Uchenna Emeribe, Anthony; Abdullahi Nasiru, Idris; Babayo, Adamu; Uko, Emmanuel K.

    2014-01-01

    Introduction. Several biomedical findings have established the effects of hypertension on haemostasis and roles of blood coagulation products in the clinical course of hypertension. Methods. This cross-sectional study aimed at determining effects of hypertension on prothrombin time (PT) and activated partial thromboplastin time (APTT) in hypertensive patients in comparison with normotensive subjects attending a tertiary hospital in Calabar. Forty-two (42) hypertensive patients and thirty-nine (39) normotensive control subjects were investigated for PT and APTT using Quick one-stage methods. Results. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) correlated positively with APTT (r = 0.3072, r = 0.4988; P < 0.05) in hypertensive patients. DBP, SBP, PT, and APTT were significantly higher in hypertensive patients when compared to normotensive subjects (P < 0.05). DBP correlated negatively with duration of illness (r = −0.3097; P < 0.05) in hypertensive patients and positively with age of normotensive subjects (r = 0.3523; P < 0.05). Conclusion. The results obtained indicated that measurements of PT and APTT may serve as indices for evaluating hemostatic abnormalities in hypertensive patients and guide for antihypertensive therapy. However, to have better understanding of hemostatic activities in hypertension, it is recommended to conduct D-dimer, platelet factors, and protein assays. PMID:25477963

  8. Induction of microglial toll-like receptor 4 by prothrombin kringle-2: a potential pathogenic mechanism in Parkinson's disease.

    PubMed

    Shin, Won-Ho; Jeon, Min-Tae; Leem, Eunju; Won, So-Yoon; Jeong, Kyoung Hoon; Park, Sang-Joon; McLean, Catriona; Lee, Sung Joong; Jin, Byung Kwan; Jung, Un Ju; Kim, Sang Ryoung

    2015-01-01

    Microglia-mediated neuroinflammation may play an important role in the initiation and progression of dopaminergic (DA) neurodegeneration in Parkinson's disease (PD), and toll-like receptor 4 (TLR4) is essential for the activation of microglia in the adult brain. However, it is still unclear whether patients with PD exhibit an increase in TLR4 expression in the brain, and whether there is a correlation between the levels of prothrombin kringle-2 (pKr-2) and microglial TLR4. In the present study, we first observed that the levels of pKr-2 and microglial TLR4 were increased in the substantia nigra (SN) of patients with PD. In rat and mouse brains, intranigral injection of pKr-2, which is not directly toxic to neurons, led to the disruption of nigrostriatal DA projections. Moreover, microglial TLR4 was upregulated in the rat SN and in cultures of the BV-2 microglial cell line after pKr-2 treatment. In TLR4-deficient mice, pKr-2-induced microglial activation was suppressed compared with wild-type mice, resulting in attenuated neurotoxicity. Therefore, our results suggest that pKr-2 may be a pathogenic factor in PD, and that the inhibition of pKr-2-induced microglial TLR4 may be protective against degeneration of the nigrostriatal DA system in vivo. PMID:26440368

  9. Characteristics of total gaseous mercury (TGM) concentrations in an industrial complex in South Korea: impacts from local sources

    NASA Astrophysics Data System (ADS)

    Seo, Yong-Seok; Jeong, Seung-Pyo; Holsen, Thomas M.; Han, Young-Ji; Choi, Eunhwa; Park, Eun Ha; Kim, Tae Young; Eum, Hee-Sang; Park, Dae Gun; Kim, Eunhye; Kim, Soontae; Kim, Jeong-Hun; Choi, Jaewon; Yi, Seung-Muk

    2016-08-01

    Total gaseous mercury (TGM) concentrations were measured every 5 min in Pohang, Gyeongsangbuk-do, Korea, during summer (17-23 August 2012), fall (9-17 October 2012), winter (22-29 January 2013), and spring (26 March-3 April 2013) to (1) characterize the hourly and seasonal variations of atmospheric TGM concentrations; (2) identify the relationships between TGM and co-pollutants; and (3) identify likely source directions and locations of TGM using the conditional probability function (CPF), conditional bivariate probability function (CBPF) and total potential source contribution function (TPSCF). The TGM concentration was statistically significantly highest in fall (6.7 ± 6.4 ng m-3), followed by spring (4.8 ± 4.0 ng m-3), winter (4.5 ± 3.2 ng m-3) and summer (3.8 ± 3.9 ng m-3). There was a weak but statistically significant negative correlation between the TGM concentration and ambient air temperature (r = -0.08, p<0.05). Although the daytime temperature (14.7 ± 10.0 °C) was statistically significantly higher than that in the nighttime (13.0 ± 9.8 °C) (p<0.05), the daytime TGM concentration (5.3 ± 4.7 ng m-3) was statistically significantly higher than that in the nighttime (4.7 ± 4.7 ng m-3) (p<0.01), possibly due to local emissions related to industrial activities and activation of local surface emission sources. The observed ΔTGM / ΔCO was significantly lower than that of Asian long-range transport, but similar to that of local sources in Korea and in US industrial events, suggesting that local sources are more important than those of long-range transport. CPF, CBPF and TPSCF indicated that the main sources of TGM were iron and manufacturing facilities, the hazardous waste incinerators and the coastal areas.

  10. Macrocyclic lanthanide complexes as artificial nucleases and ribonucleases: effects of pH, metal ionic radii, number of coordinated water molecules, charge, and concentrations of the metal complexes.

    PubMed

    Chang, C Allen; Wu, Bo Hong; Kuan, Bu Yuan

    2005-09-19

    We have been interested in the design, synthesis, and characterization of artificial nucleases and ribonucleases by employing macrocyclic lanthanide complexes because their high thermodynamic stability, low kinetic lability, high coordination number, and charge density (Lewis acidity) allow more design flexibility and stability. In this paper, we report the study of the use of the europium(III) complex, EuDO2A+ (DO2A is 1,7-dicarboxymethyl-1,4,7,10-tetraazacyclododecane) and other lanthanide complexes (i.e., LaDO2A+, YbDO2A+, EuK21DA+, EuEDDA+, and EuHEDTA where K21DA is 1,7-diaza-4,10,13-trioxacyclopentadecane-N,N'-diacetic acid, EDDA is ethylenediamine-N,N'-diacetic acid, and HEDTA is N-hydroxyethyl-ethylenediamine-N,N',N'-triacetic acid), as potential catalysts for the hydrolysis of the phosphodiester bond of BNPP (sodium bis(4-nitrophenyl)-phosphate). For the pH range 7.0-11.0 studied, EuDO2A+ promotes BNPP hydrolysis with the quickest rates among LaDO2A+, EuDO2A+, and YbDO2A+. This indicates that charge density is not the only factor affecting the reaction rates. Among the four complexes, EuDO2A+, EuK21DA+, EuEDDA+, and EuHEDTA, with their respective number of inner-sphere coordinated water molecules three, two, five, and three, EuEDDA+, with the greatest number of inner-sphere coordinated water molecules and a positive charge, promotes BNPP hydrolysis more efficiently at pH below 8.4, and the observed rate trend is EuEDDA+ > EuDO2A+ > EuK21DA+ > EuHEDTA. At pH > 8.4, the EuEDDA+ solution becomes misty and precipitates form. At pH 11.0, the hydrolysis rate of BNPP in the presence of EuDO2A+ is 100 times faster than that of EuHEDTA, presumably because the positively charged EuDO2A+ is more favorable for binding with the negatively charged phosphodiester compounds. The logarithmic hydrolysis constants (pKh) were determined, and are reported in the parentheses, by fitting the kinetic k(obs) data vs pH for EuDO2A+ (8.4), LaDO2A+ (8.4), YbDO2A+ (9.4), EuK21DA+ (7

  11. The Aqueous Thermodynamics and Complexation Reactions of Anionic Silica Species to High Concentration: Effects on Neutralization of Leaked Tank Wastes and Migration of Radionuclides in the Subsurface

    SciTech Connect

    Felmy, Andrew R.; Choppin, Gregory; Dixon, David A.

    2002-06-01

    Highly basic tank wastes contain several important radionuclides, including {sup 90}Sr, {sup 99}Tc, and {sup 60}Co, as well as actinide elements (i.e., isotopes of U, Pu, and Am). These highly basic tank wastes are known to have leaked into the vadose zone at the Hanford Site. Upon entering the sediments in the vadose zone, the highly basic solutions dissolve large concentrations of silica from the silica and aluminosilicate minerals present in the subsurface. These dissolution reactions alter the chemical composition of the leaking solutions, transforming them from a highly basic (as high as 2M NaOH) solution into a pore solution with a very high concentration of dissolved silica and a significantly reduced pH. This moderately basic (pH 9 to 11), high-silica solution has the potential to complex radionuclides and move through the subsurface. Such strong radionuclide complexation is a currently unconsidered transport vector that has the potential to expedite radionuclide transport through the vadose zone. These strong complexation effects have the ability to significantly alter current conceptual models of contaminant migration beneath leaking tanks. In this project, we are determining the aqueous thermodynamics and speciation of dissolved silica and silica-radionuclide complexes to high silica concentration using a combination of (1) studies of chemical species structure and composition [via nuclear magnetic resonance (NMR) and, where applicable, laser-induced fluorescence spectroscopy and x-ray absorption spectroscopy] (2) molecular simulations to help identify key species structures and assist in interpreting experimental measurements (3) fundamental physical chemistry measurements, including solubility, electromotive force, and isopiestic measurements, to obtain the necessary thermodynamic data for predicting contaminant complexation and waste neutralization reactions. The radioactive elements we are studying include Sr, Co, Cs, Am(III), and U(VI).

  12. Influence of domestic pets on soil concentrations of dissolved organic carbon, nitrogen, and phosphorus under turfgrass in apartment complexes of Central Texas, USA

    NASA Astrophysics Data System (ADS)

    Steele, M.; Aitkenhead-Peterson, J. A.

    2009-12-01

    High nitrogen (N) and phosphorus (P) watershed loading rates increases the concentration and loads present in urban streams and rivers, resulting in eutrophication and degradation of surface water quality. Domestic pet animal feed may represent a significant proportion of nitrogen loading in urban watersheds, and because it is deposited directly on the watershed surface may have a large effect on N loads in urban surface waters (Baker et al. 2001). Animal manure has long been used to increase soil N and phosphorus concentrations for the purpose of growing agricultural crops; however, little is known about unintentional urban manuring resulting from a high density of domesticated pets. The purpose of this study is to determine if the presence of domesticated animals in high density urban developments results in increased concentrations of soil dissolved organic carbon (DOC), N, and P and the potential to contribute to loading of urban streams. Composite soil samples from the 0 to 5 cm and 5 to 10 cm soil depth were collected from apartment complexes in Bryan/College Station (BCS) and San Antonio, Texas during August, 2009. Apartment complexes were randomly located around the city and were chosen based on their rules regarding pet ownership. Four apartment complexes that allowed all domestic pets were compared to four that did not allow any domestic pets on the property. A 10:1 water extraction of field moist soil was conducted immediately after sampling. Soil water extracts were analyzed for DOC, total dissolved nitrogen (TDN), nitrate-N, ammonium-N, dissolved organic N, and orthophosphate-P. Results indicated significantly increased concentrations of DOC and N species at both depths in BCS apartments that allowed pets compared to those that did not; however, opposite trends were found in San Antonio. There is a trend for increased concentrations of orthophosphate-P at both locations. Baker, L.A., D. Hope, Y. Xu, et al. 2001. Nitrogen balance for the central Arizona

  13. Influence of zinc concentration on structure, complex permittivity and permeability of Ni-Zn ferrites at high frequency

    NASA Astrophysics Data System (ADS)

    Jiang, Nan-Nan; Yang, Yang; Zhang, Yu-Xiang; Zhou, Jian-Ping; Liu, Peng; Deng, Chao-Yong

    2016-03-01

    Polycrystalline soft magnetic nickel-zinc ferrites with chemical composition Ni1-xZnxFe2O4, where x=0, 0.2, 0.4, 0.6, 0.65, 0.7, 0.75, and 0.8, were prepared by solid state reaction method. We researched the effect of zinc concentration on the lattice parameter, crystal morphology and electromagnetic properties at high frequency. Results show that ε‧ and ε″ decline with increasing frequency until they reach almost constants over 3 MHz to 1 GHz. The dielectric constant achieves a maximum when the Zn concentration is 0.8. The value of ε‧ slightly declines with increasing frequency in the range of 2-18 GHz. The spectra of the permeability displays a relaxation resonance for the ferrites with x=0, 0.2, and 0.4 in 3 MHz to 1 GHz frequency range. The permeability is ruled by Snoek's law, which results in the values of μ‧ decreased fast below 2 GHz and smaller than 1 above 2 GHz. The value of μ‧ reaches maximum and μ″ shows minimum for the samples around x=0.75 in 2-18 GHz range. The magnetic permeability μ‧ decreases in an external magnetic field, and shows two resonance peaks corresponding to domain wall and spin rotation resonance. The resonance peaks shift to higher frequency with increasing the external magnetic field. But the permeability has no clear response for magnetic field when zinc concentration is much higher.

  14. Stress Tolerance of Antibody-Poly(Amino Acid) Complexes for Improving the Stability of High Concentration Antibody Formulations.

    PubMed

    Izaki, Shunsuke; Kurinomaru, Takaaki; Handa, Kenji; Kimoto, Tomoaki; Shiraki, Kentaro

    2015-08-01

    The stabilization of antibodies in aqueous solution against physical stress remains a problematic issue for pharmaceutical applications. Recently, protein-polyelectrolyte complex (PPC) formation using poly(amino acids) was proposed to prepare antibody formulation in a salt-dissociable precipitated state without protein denaturation. Here, we investigated the stabilization effect of PPC of therapeutic antibodies with poly-l-glutamic acid on agitation and thermal stress as forms of mechanical and non-mechanical stress, respectively. The precipitated state of PPC prevented the inactivation and aggregation induced by agitation. Similar results were obtained using the suspension state of PPC, but the stabilizing effects were slightly inferior to those of the PPC precipitate. PPC precipitate and PPC suspension prevented heat-induced inactivation of the antibodies, but showed little effect on heat-induced aggregation. Thus, PPC is a new candidate as a simple storage method for antibodies in aqueous solution, as an alternative state for freeze-drying. PMID:26036204

  15. Effects of pH and fulvic acids concentration on the stability of fulvic acids--cerium (IV) oxide nanoparticle complexes.

    PubMed

    Oriekhova, Olena; Stoll, Serge

    2016-02-01

    The behavior of cerium (IV) oxide nanoparticles has been first investigated at different pH conditions. The point of zero charge was determined as well as the stability domains using dynamic light scattering, nanoparticle tracking analysis and scanning electron microscopy. A baseline hydrodynamic diameter of 180 nm was obtained indicating that individual CeO2 nanoparticles are forming small aggregates. Then we analyzed the particle behavior at variable concentrations of fulvic acids for three different pH-electrostatic scenarios corresponding to positive, neutral and negative CeO2 surface charges. The presence of fulvic acids was found to play a key role on the CeO2 stability via the formation of electrostatic complexes. It was shown that a small amount of fulvic acids (2 mg L(-1)), representative of environmental fresh water concentrations, is sufficient to stabilize CeO2 nanoparticles (50 mg L(-1)). When electrostatic complexes are formed between negatively charged FAs and positively charged CeO2 NPs the stability of such complexes is obtained with time (up to 7 weeks) as well as in pH changing conditions. Based on zeta potential variations we also found that the fulvic acids are changing the CeO2 acid-base surface properties. Obtained results presented here constitute an important outcome in the domain of risk assessment, transformation and removal of engineered nanomaterials released into the environment. PMID:26347935

  16. Diagnostic ramifications of ocular vascular occlusion as a first thrombotic event associated with factor V Leiden and prothrombin gene heterozygosity

    PubMed Central

    Schockman, Samantha; Glueck, Charles J; Hutchins, Robert K; Patel, Jaykumar; Shah, Parth; Wang, Ping

    2015-01-01

    Aim This study aimed to assess the diagnostic ramifications of vascular occlusion of the ocular vein and artery as a first thrombotic event associated with factor V Leiden (FVL) and/or prothrombin gene (PTG) heterozygosity. Methods Patients with ocular vein (n=191) and artery (n=74) occlusion, free of cardioembolic etiologies, were sequentially referred from vitreoretinal specialists for measurement of thrombophilia-hypofibrinolysis and compared to 110 healthy normal controls. Results Of the 265 patients, 29 (11%; 17 women, 12 men) of all referred ocular vascular occlusion (OVO) cases were found to be heterozygous for FVL and/or PTG, including 16 with FVL, 12 with PTG, and 1 with both. Of the 29 cases, 16 had central retinal vein occlusion (CRVO), 2 branch retinal vein occlusion (BRVO), 5 nonarteritic anterior ischemic optic neuropathy (NA-AION), 3 retinal artery occlusion (RAO), 2 amaurosis fugax (AF), and 1 had both CRVO and RAO. Of the 16 FVL cases, 15 (94%) had OVO as a first thrombotic event without prior deep venous thrombosis (DVT) or pulmonary embolism (PE); 6 (38%) also had other thrombotic events, including recurrent miscarriage, osteonecrosis, ischemic stroke, and/or ischemic colitis; and 5 (31%) had immediate family members with previous venous thromboembolism (VTE). Of the 12 PTG cases, 9 (75%) had OVO as a first thrombotic event, 5 (42%) experienced VTE other than DVT or PE, and 6 (50%) had immediate family members with VTE. In one patient with both FVL and PTG, DVT occurred before BRVO. Of the 17 women with FVL and/or PTG mutations, 7 (41%) experienced ≥1 miscarriage, 6 (35%) were on estrogen therapy, and 1 (6%) was on clomiphene. Conclusion Of the 265 patients with OVO, 29 (11%) had FVL and/or PTG, and 83% of these 29 cases presented with OVO as their first thrombotic event. By diagnosing thrombophilia as an etiology for OVO, the ophthalmologist opens a window to family screening and preventive therapy. PMID:25897198

  17. Factor V Leiden, Prothrombin and MTHFR Mutation in Patients with Preeclamsia, Intrauterine Growth Restriction and Placental Abruption

    PubMed Central

    Livrinova, Vesna; Lega, Marija Hadzi; Dimcheva, Anita Hristova; Samardziski, Igor; Isjanovska, Rozalinda

    2015-01-01

    BACKGROUND: Factor V Leiden, Prothrombin and MTHFR gene mutation, could have an influence in pregnancy with adverse outcome Preeclamsia, IUGR and Placental abruption. AIM: The aim of this study is to investigate the presence of above mentioned inherited thrombophilias and its statistical significance, distribution among the complicated and normal pregnancy, and relative risk for carrier of mutation to develop preeclampsia, IUGR and placental abruption. MATERIAL AND METHODS: Prospective cohort study is implemented at University Clinic for Obstetric and Gynecology in Skopje, Republic of Macedonia. The study included 109 delivered patients: 40 with preeclapmsia, 22 with IUGR, 17 with placental abruption and 30 as control group with normal pregnancy. The amount of 3 ml venous blood has been used for detection of these point mutations using ThromboStrip -Opegen, QIAGEN kit manufactured for thrombotic risk. RESULTS: The highest frequency was found: in the group with preeclampsia 35% were MTHFR homozygous, IUGR -MTHFR heterozygous 45%, Placental abruption- 52.9% MTHFR heterozygous, and in the control group without thrombophilia 56.7%. There were combined thrombophilia in 3 patients. There aren`t statistical significance in presence of thrombophilia among groups (p > 0.05). Statistical significance (p < 0.05) was found between carriers of MTHFR homozygous in preeclampsia and group with placental abruption and control group. Relative risk in IUGR group for MTHFR homozygous was 5.54 (1.37

  18. Dietary Tocotrienol/γ-Cyclodextrin Complex Increases Mitochondrial Membrane Potential and ATP Concentrations in the Brains of Aged Mice

    PubMed Central

    Schloesser, Anke; Esatbeyoglu, Tuba; Piegholdt, Stefanie; Dose, Janina; Ikuta, Naoko; Okamoto, Hinako; Ishida, Yoshiyuki; Terao, Keiji; Matsugo, Seiichi; Rimbach, Gerald

    2015-01-01

    Brain aging is accompanied by a decrease in mitochondrial function. In vitro studies suggest that tocotrienols, including γ- and δ-tocotrienol (T3), may exhibit neuroprotective properties. However, little is known about the effect of dietary T3 on mitochondrial function in vivo. In this study, we monitored the effect of a dietary T3/γ-cyclodextrin complex (T3CD) on mitochondrial membrane potential and ATP levels in the brain of 21-month-old mice. Mice were fed either a control diet or a diet enriched with T3CD providing 100 mg T3 per kg diet for 6 months. Dietary T3CD significantly increased mitochondrial membrane potential and ATP levels compared to those of controls. The increase in MMP and ATP due to dietary T3CD was accompanied by an increase in the protein levels of the mitochondrial transcription factor A (TFAM). Furthermore, dietary T3CD slightly increased the mRNA levels of superoxide dismutase, γ-glutamyl cysteinyl synthetase, and heme oxygenase 1 in the brain. Overall, the present data suggest that T3CD increases TFAM, mitochondrial membrane potential, and ATP synthesis in the brains of aged mice. PMID:26301044

  19. Evaluation of AERMOD and CALPUFF for predicting ambient concentrations of total suspended particulate matter (TSP) emissions from a quarry in complex terrain.

    PubMed

    Tartakovsky, Dmitry; Broday, David M; Stern, Eli

    2013-08-01

    Concentrations of particulate emissions from a quarry located in hilly terrain were calculated by two common atmospheric dispersion models, AERMOD and CALPUFF. Evaluation of these models for emissions from quarries/open pit mines that are located in complex topography is missing from the literature. Due to severe uncertainties in the input parameters, numerous scenarios were simulated and model sensitivity was studied. Model results were compared among themselves, and to measured total suspended particulate (TSP). For a wide range of meteorological and topographical conditions studied, AERMOD predictions were in a better agreement with the measurements than those obtained by CALPUFF. The use of AERMOD's "Open pit" tool seems unnecessary when accurate digital topographic data are available. Onsite meteorological data are shown to be crucial for reliable dispersion calculations in complex terrain. PMID:23673194

  20. Covalent co-immobilization of heparin/laminin complex that with different concentration ratio on titanium surface for selectively direction of platelets and vascular cells behavior

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Chen, Yuan; Liu, Tao; Wang, Xue; Liu, Yang; Wang, Yuan; Chen, Junying; Huang, Nan

    2014-10-01

    Surface biofunctional modification of coronary artery stent to improve the hemocompatibility and selectively accelerate endothelium regeneration but prevent restenosis have been become a new hotspot. For this, a novel method was developed in this work by co-immobilization of Ln and heparin complex on poly-L-lysine modified Ti surface. Take the advantage of the specific interaction between Ln and heparin, Ln and heparin complexes with different concentration ratios were set up for creating different exposure density of these two types of biomolecules. According to biocompatibility evaluation results, the Hep/Ln complexes modified surface displayed less platelet adhesion and activation. Especially, on L(150)H and L(200)H surface, the AT III binding quantity, APTT value and anti-coagulation property of modified surface were significantly promoted. Furthermore, the adherent density and proliferation activity of ECs and EPCs were positively correlated with Ln concentration. Notably, the proliferation of both ECs and EPCs on L(100)H, L(150)H and L(200)H surface were greatly promoted. Another hand, the proliferation activity of SMCs was significantly inhibited on Hep/Ln modified surfaces, which was considered mainly due to the inhibitory effect of heparin to SMCs. According to the existing results, this study demonstrated that in a certain range of heparin and laminin concentration ratio, the biological behavior of platelets, ECs, EPCs and SMCs could be selectively directed. We suggested that this article provided a potential method to construct an adequate platform on a stent surface for accelerate endothelialization with low side effects.

  1. Method for determining molar concentrations of metabolites in complex solutions from two-dimensional 1H-13C NMR spectra.

    PubMed

    Lewis, Ian A; Schommer, Seth C; Hodis, Brendan; Robb, Kate A; Tonelli, Marco; Westler, William M; Sussman, Michael R; Markley, John L

    2007-12-15

    One-dimensional (1D) (1)H nuclear magnetic resonance (NMR) spectroscopy is used extensively for high-throughput analysis of metabolites in biological fluids and tissue extracts. Typically, such spectra are treated as multivariate statistical objects rather than as collections of quantifiable metabolites. We report here a two-dimensional (2D) (1)H-(13)C NMR strategy (fast metabolite quantification, FMQ, by NMR) for identifying and quantifying the approximately 40 most abundant metabolites in biological samples. To validate this technique, we prepared mixtures of synthetic compounds and extracts from Arabidopsis thaliana, Saccharomyces cerevisiae, and Medicago sativa. We show that accurate (technical error 2.7%) molar concentrations can be determined in 12 min using our quantitative 2D (1)H-(13)C NMR strategy. In contrast, traditional 1D (1)H NMR analysis resulted in 16.2% technical error under nearly ideal conditions. We propose FMQ by NMR as a practical alternative to 1D (1)H NMR for metabolomics studies in which 50-mg (extract dry weight) samples can be obtained. PMID:17985927

  2. Complex Catchment Processes that Control Stream Nitrogen and Organic Matter Concentrations in a Northeastern USA Upland Catchment

    NASA Astrophysics Data System (ADS)

    Sebestyen, S. D.; Shanley, J. B.; Pellerin, B.; Saraceno, J.; Aiken, G. R.; Boyer, E. W.; Doctor, D. H.; Kendall, C.

    2009-05-01

    There is a need to understand the coupled biogeochemical and hydrological processes that control stream hydrochemistry in upland forested catchments. At watershed 9 (W-9) of the Sleepers River Research Watershed in the northeastern USA, we use high-frequency sampling, environmental tracers, end-member mixing analysis, and stream reach mass balances to understand dynamic factors affect forms and concentrations of nitrogen and organic matter in streamflow. We found that rates of stream nitrate processing changed during autumn baseflow and that up to 70% of nitrate inputs to a stream reach were retained. At the same time, the stream reach was a net source of the dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) fractions of dissolved organic matter (DOM). The in-stream nitrate loss and DOM gains are examples of hot moments of biogeochemical transformations during autumn when deciduous litter fall increases DOM availability. As hydrological flowpaths changed during rainfall events, the sources and transformations of nitrate and DOM differed from baseflow. For example, during storm flow we measured direct inputs of unprocessed atmospheric nitrate to streams that were as large as 30% of the stream nitrate loading. At the same time, stream DOM composition shifted to reflect inputs of reactive organic matter from surficial upland soils. The transport of atmospheric nitrate and reactive DOM to streams underscores the importance of quantifying source variation during short-duration stormflow events. Building upon these findings we present a conceptual model of interacting ecosystem processes that control the flow of water and nutrients to streams in a temperate upland catchment.

  3. The relationship between the bone mineral density and urinary cadmium concentration of residents in an industrial complex

    SciTech Connect

    Shin, Minah; Paek, Domyung; Yoon, Chungsik

    2011-01-15

    Background: An association between cadmium exposure and bone mineral density (BMD) has been demonstrated in elderly women, but has not been well studied in youths and men. Some studies report either no or a weak association between cadmium exposure and bone damage. Objectives: This study was designed to investigate the relationship between the urinary cadmium (U-Cd) levels and BMD of females and males of all ages. Methods: A total of 804 residents near an industrial complex were surveyed in 2007. U-Cd and BMD on the heel (non-dominant calcaneus) were analyzed with AAS-GTA and Dual-Energy X-ray absorptiometry, respectively. Demographic characteristics were collected by structured questionnaires. Osteoporosis and osteopenia were defined by BMD cut-off values and T-scores set by the WHO; T score>-1, normal; -2.5=}1.0 {mu}g/g creatinine) in females (OR=2.92; 95% CI, 1.51-5.64) and in males (OR=3.37; 95% CI, 1.09-10.38). With the multiple linear regression model, the BMD of the adult group was negatively associated with U-Cd (<0.05), gender (female, p<0.001) and age (p<0.001). The BMD of participants who were {<=}19 years of age was negatively associated with gender (female, p<0.01), whereas it was positively associated with age and BMI (p<0.001). BMD was not associated with exercise, smoking habits, alcohol consumption, job or parental education. Conclusion: Results suggested that U-Cd might be associated with osteopenia as well as osteoporosis in both male and female adults. Age and female gender were negatively associated with BMD in the adult group, whereas age was positively

  4. Charge carrier effective mass and concentration derived from combination of Seebeck coefficient and 125Te NMR measurements in complex tellurides

    NASA Astrophysics Data System (ADS)

    Levin, E. M.

    2016-06-01

    Thermoelectric materials utilize the Seebeck effect to convert heat to electrical energy. The Seebeck coefficient (thermopower), S , depends on the free (mobile) carrier concentration, n , and effective mass, m*, as S ˜m*/n2 /3 . The carrier concentration in tellurides can be derived from 125Te nuclear magnetic resonance (NMR) spin-lattice relaxation measurements. The NMR spin-lattice relaxation rate, 1 /T1 , depends on both n and m* as 1 /T1˜(m*)3/2n (within classical Maxwell-Boltzmann statistics) or as 1 /T1˜(m*)2n2 /3 (within quantum Fermi-Dirac statistics), which challenges the correct determination of the carrier concentration in some materials by NMR. Here it is shown that the combination of the Seebeck coefficient and 125Te NMR spin-lattice relaxation measurements in complex tellurides provides a unique opportunity to derive the carrier effective mass and then to calculate the carrier concentration. This approach was used to study A gxS bxG e50-2xT e50 , well-known GeTe-based high-efficiency tellurium-antimony-germanium-silver thermoelectric materials, where the replacement of Ge by [Ag+Sb] results in significant enhancement of the Seebeck coefficient. Values of both m* and n derived using this combination show that the enhancement of thermopower can be attributed primarily to an increase of the carrier effective mass and partially to a decrease of the carrier concentration when the [Ag+Sb] content increases.

  5. Investigating the differences between receptor and dispersion modeling for concentration prediction and health risk assessment of volatile organic compounds from petrochemical industrial complexes.

    PubMed

    Chen, Wei-Hsiang; Chen, Zheng-Bin; Yuan, Chung-Shin; Hung, Chung-Hsuang; Ning, Shu-Kuang

    2016-01-15

    Receptor and dispersion models both provide important information to help understand the emissions of volatile organic compounds (VOCs) and develop effective management strategies. In this study, differences between the predicted concentrations of two models and the associated impacts on the estimated health risks due to different theories behind two models were investigated. Two petrochemical industrial complexes in Kaohsiung city of southern Taiwan were selected as the sites for this comparison. Although the study compares the approaches by applying the methods to this specific area, the results are expected to be adopted for other areas or industries. Ninety-nine VOC concentrations at eight monitoring sites were analyzed, with the effects of diurnal temperature and seasonal humidity variations being considered. The Chemical Mass Balance (CMB) receptor model was used for source apportionment, while the Industrial Source Complex (ISC) dispersion model was used to predict the VOC concentrations at receptor sites. In the results of receptor modeling, 54% ± 11% and 49% ± 20% of the monitored concentrations were contributed by process emissions in two complexes, whereas the numbers increased to 78% ± 41% and 64% ± 44% in the results of dispersion modeling. Significant differences were observed between two model predictions (p < 0.05). The receptor model was more reproducible given the smaller variances of its results. The effect of seasonal humidity variation on two model predictions was not negligible. Similar findings were observed given that the cancer and non-cancer risks estimated by the receptor model were lower but more reproducible. The adverse health risks estimated by the dispersion model exceeded and were 75.3%-132.4% of the values estimated by using the monitored data, whereas the percentages were lowered to the range from 27.4% to 53.8% when the prediction was performed by using the receptor model. As the results of different models could be

  6. Prothrombin Time and Activated Partial Thromboplastin Time Testing: A Comparative Effectiveness Study in a Million-Patient Sample

    PubMed Central

    Capoor, Manu N.; Stonemetz, Jerry L.; Baird, John C.; Ahmed, Fahad S.; Awan, Ahsan; Birkenmaier, Christof; Inchiosa, Mario A.; Magid, Steven K.; McGoldrick, Kathryn; Molmenti, Ernesto; Naqvi, Sajjad; Parker, Stephen D.; Pothula, S. M.; Shander, Aryeh; Steen, R. Grant; Urban, Michael K.; Wall, Judith; Fischetti, Vincent A.

    2015-01-01

    Background A substantial fraction of all American healthcare expenditures are potentially wasted, and practices that are not evidence-based could contribute to such waste. We sought to characterize whether Prothrombin Time (PT) and activated Partial Thromboplastin Time (aPTT) tests of preoperative patients are used in a way unsupported by evidence and potentially wasteful. Methods and Findings We evaluated prospectively-collected patient data from 19 major teaching hospitals and 8 hospital-affiliated surgical centers in 7 states (Delaware, Florida, Maryland, Massachusetts, New Jersey, New York, Pennsylvania) and the District of Columbia. A total of 1,053,472 consecutive patients represented every patient admitted for elective surgery from 2009 to 2012 at all 27 settings. A subset of 682,049 patients (64.7%) had one or both tests done and history and physical (H&P) records available for analysis. Unnecessary tests for bleeding risk were defined as: PT tests done on patients with no history of abnormal bleeding, warfarin therapy, vitamin K-dependent clotting factor deficiency, or liver disease; or aPTT tests done on patients with no history of heparin treatment, hemophilia, lupus anticoagulant antibodies, or von Willebrand disease. We assessed the proportion of patients who received PT or aPTT tests who lacked evidence-based reasons for testing. Conclusions This study sought to bring the availability of big data together with applied comparative effectiveness research. Among preoperative patients, 26.2% received PT tests, and 94.3% of tests were unnecessary, given the absence of findings on H&P. Similarly, 23.3% of preoperative patients received aPTT tests, of which 99.9% were unnecessary. Among patients with no H&P findings suggestive of bleeding risk, 6.6% of PT tests and 7.1% of aPTT tests were either a false positive or a true positive (i.e. indicative of a previously-undiagnosed potential bleeding risk). Both PT and aPTT, designed as diagnostic tests, are

  7. Near infrared-red models for the remote estimation of chlorophyll- a concentration in optically complex turbid productive waters: From in situ measurements to aerial imagery

    NASA Astrophysics Data System (ADS)

    Gurlin, Daniela

    Today the water quality of many inland and coastal waters is compromised by cultural eutrophication in consequence of increased human agricultural and industrial activities and remote sensing is widely applied to monitor the trophic state of these waters. This study explores near infrared-red models for the remote estimation of chlorophyll-a concentration in turbid productive waters and compares several near infrared-red models developed within the last 35 years. Three of these near infrared-red models were calibrated for a dataset with chlorophyll-a concentrations from 2.3 to 81.2 mg m -3 and validated for independent and statistically significantly different datasets with chlorophyll-a concentrations from 4.0 to 95.5 mg m-3 and 4.0 to 24.2 mg m-3 for the spectral bands of the MEdium Resolution Imaging Spectrometer (MERIS) and Moderate-resolution Imaging Spectroradiometer (MODIS). The developed MERIS two-band algorithm estimated chlorophyll-a concentrations from 4.0 to 24.2 mg m-3, which are typical for many inland and coastal waters, very accurately with a mean absolute error 1.2 mg m-3. These results indicate a high potential of the simple MERIS two-band algorithm for the reliable estimation of chlorophyll-a concentration without any reduction in accuracy compared to more complex algorithms, even though more research seems required to analyze the sensitivity of this algorithm to differences in the chlorophyll-a specific absorption coefficient of phytoplankton. Three near infrared-red models were calibrated and validated for a smaller dataset of atmospherically corrected multi-temporal aerial imagery collected by the hyperspectral airborne imaging spectrometer for applications (AisaEAGLE). The developed algorithms successfully captured the spatial and temporal variability of the chlorophyll-a concentrations and estimated chlorophyll- a concentrations from 2.3 to 81.2 mg m-3 with mean absolute errors from 4.4 mg m-3 for the AISA two band algorithm to 5.2 mg m-3

  8. Prothrombin time (PT)

    MedlinePlus

    ... control blood clotting become over active ( disseminated intravascular coagulation ) Liver disease Low level of vitamin K If ... Saunders; 2011:chap 42. Schmaier AH, Miller JL. Coagulation and fibrinolysis. In: McPherson RA, Pincus MR, eds. ...

  9. Concentrations, profiles, and estimated human exposures for polychlorinated dibenzo-p-dioxins and dibenzofurans from electronic waste recycling facilities and a chemical industrial complex in Eastern China

    SciTech Connect

    Ma, J.; Kannan, K.; Cheng, J.; Horii, Y.; Wu, Q.; Wang, W.

    2008-11-15

    Electronic shredder waste and dust from e-waste facilities, and leaves and surface soil collected in the vicinity of a large scale e-waste recycling facility in Taizhou, Eastern China, were analyzed for total dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) including 2,3,7,8-substituted congeners. We also determined PCDD/Fs in surface agricultural soils from several provinces in China for comparison with soils from e-waste facilities. Concentrations of total PCDD/Fs were high in all of the matrices analyzed and ranged from 30.9 to 11,400 pg/g for shredder waste, 3460 to 9820 pg/g dry weight for leaves, 2560 to 148,000 pg/g dry weight for workshop-floor dust, and 854 to 10200 pg/g dry weight for soils. We also analyzed surface soils from a chemical industrial complex (a coke-oven plant, a coal-fired power plant, and a chlor-alkali plant) in Shanghai. Concentrations of total PCDD/Fs in surface soil from the chemical industrial complex were lower than the concentrations found in soils from e-waste recycling plants, but higher than the concentrations found in agricultural soils. Agricultural soils from six cities in China contained low levels of total PCDD/Fs. Profiles of dioxin toxic equivalents (TEQs) of 2,3,7,8-PCDD/Fs in soils from e-waste facilities in Taizhou differed from the profiles found in agricultural soils. The estimated daily intakes of TEQs of PCDD/Fs via soil/dust ingestion and dermal exposure were 2 orders of magnitude higher in people at e-waste recycling facilities than in people at the chemical industrial site, implying greater health risk for humans from dioxin exposures at e-waste recycling facilities. The calculated TEQ exposures for e-waste workers from dust and soil ingestion alone were 2-3 orders of magnitude greater than the exposures from soils in reference locations. 37 refs., 1 fig., 2 tabs.

  10. Application of a UV-Vis submersible probe for capturing changes in DOC concentrations across a mire complex during the snowmelt and summer periods

    NASA Astrophysics Data System (ADS)

    Avagyan, Armine; Runkle, Benjamin; Kutzbach, Lars

    2013-04-01

    An accurate quantification of dissolved organic carbon (DOC) is crucial for understanding changes in water resources under the influence of climate, land use and urbanization. However, the conventionally used methods do not allow high frequency in situ analyses in remote or hostile environments (e.g., industrial wastewater or during environmental high-flow events, such as snowmelt or floods). In particular, missing measurements during the snowmelt period in landscapes of the boreal region can lead to significant miscalculations in regional carbon budgets. Therefore, the aim of the study was to test the performance of a portable, submersible UV-Vis spectrophotometer (spectro::lyser, s::can Messtechnik GmbH, Austria) during the snowmelt period in a boreal mire-forest catchment, and to provide a conceptual understanding of the spatial and temporal dynamics of DOC concentrations during and after snowmelt. During 2011, water samples were collected from the near-pristine Ust-Pojeg mire complex in northwestern Russia (61° 56'N, 50° 13'E). Sampling started during the spring snowmelt period and continued until late fall. The mire presented a mosaic of different landscape units. The mire consisted of minerogeous (fen), ombrogenous (bog), and transitional forest-mire (lagg) zones. Water samples were taken from the surface across the mire (22 points at 50-m intervals). DOC concentrations were analyzed directly at the study site using a portable, submersible UV-Vis spectrophotometer, which uses high-resolution absorbance measurements over the wavelength range 200-742.5 nm at 2.5-nm intervals as a proxy for DOC content. Because the DOC composition of fluids varies by site, a local calibration replaced the default settings of the spectro::lyser (Global Calibration) to enhance the accuracy of the measurements. To evaluate the local calibration and correct for drift, the same samples (n = 157) were additionally analyzed using the wet persulfate oxidation method (O

  11. Monitoring of ractopamine concentration in the mixture of this feed additive with vitamin mineral complex and with swine feed by HPLC.

    PubMed

    Freire, Ellen Figueiredo; Borges, Keyller Bastos; Tanimoto, Hélio; Nogueira, Raquel Tassara; Bertolini, Lucimara Cristiane Toso; de Gaitani, Cristiane Masetto

    2013-01-01

    Ractopamine (RAC) analysis at all stages in the feed chain until its final mixing into swine feed is necessary to ensure the safety of all meat consumers and to decrease waste and the cost of supplementation of feed. Two suitable HPLC methods were developed and validated for RAC determination in vitamin mineral complex (VMC) and in swine feed. Both methods employed reverse-phase (C18 column at 40°C) and isocratic elution, but with some modifications to the methods. Validation parameters, such as selectivity, linearity, precision, trueness and robustness, were shown to be within the acceptable range. Therefore, the developed methods can be successfully applied for the monitoring of RAC concentrations in samples of VMC and swine feed ensuring economy to producers and security to consumers of swine meat. PMID:23656236

  12. Determination of Background Uranium Concentration in the Snake River Plain Aquifer under the Idaho National Engineering and Environmental Laboratory's Radioactive Waste Management Complex

    SciTech Connect

    Molly K. Leecaster; L. Don Koeppen; Gail L. Olson

    2003-06-01

    Uranium occurs naturally in the environment and is also a contaminant that is disposed of at the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering and Environmental Laboratory. To determine whether uranium concentrations in the Snake River Plain Aquifer, which underlies the laboratory, are elevated as a result of migration of anthropogenic uranium from the Subsurface Disposal Area in the RWMC, uranium background concentrations are necessary. Guideline values are calculated for total uranium, 234U, 235U, and 238U from analytical results from up to five datasets. Three of the datasets include results of samples analyzed using isotope dilution thermal ionization mass spectrometry (ID-TIMS) and two of the datasets include results obtained using alpha spectrometry. All samples included in the statistical testing were collected from aquifer monitoring wells located within 10 miles of the RWMC. Results from ID-TIMS and alpha spectrometry are combined when the data are not statistically different. Guideline values for total uranium were calculated using four of the datasets, while guideline values for 234U were calculated using only the alpha spectrometry results (2 datasets). Data from all five datasets were used to calculate 238U guideline values. No limit is calculated for 235U because the ID-TIMS results are not useful for comparison with routine monitoring data, and the alpha spectrometry results are too close to the detection limit to be deemed accurate or reliable for calculating a 235U guideline value. All guideline values presented represent the upper 95% coverage 95% confidence tolerance limits for background concentration. If a future monitoring result is above this guideline, then the exceedance will be noted in the quarterly monitoring report and assessed with respect to other aquifer information. The guidelines (tolerance limits) for total U, 234U, and 238U are 2.75 pCi/L, 1.92 pCi/L, and 0.90 pCi/L, respectively.

  13. Development and application of a remote sensing-based Chlorophyll-a concentration prediction model for complex coastal waters of Hong Kong

    NASA Astrophysics Data System (ADS)

    Nazeer, Majid; Nichol, Janet E.

    2016-01-01

    Despite recent advances in estimation of water quality parameters using satellite remote sensing, the estimation of Chlorophyll-a (Chl-a) has remained problematic due to optical complexity of coastal waters and imprecise atmospheric correction of imagery. Local environmental agencies require frequent measurement and monitoring of Chl-a over coastal regions at detailed level, for water quality assessment and control. To monitor Chl-a around the complex coastal waters of Hong Kong using remote sensing, 27 Landsat Thematic Mapper (TM) and Enhanced Thematic Mapper Plus (ETM+) images over a 13-year period from January 2000 to December 2012, were used, along with 120 in situ Chl-a samples. Atmospherically corrected Landsat TM/ETM+ bands 1-4 along with in situ Chl-a data were used to develop and validate regression models for a Chl-a concentration range of 0.3-13.0 μg/l. Validation results indicated that the ratio of band 3 (red, 0.63-0.69 μm) and the square of band 1 (blue, 0.45-0.52 μm), with correlation coefficient (R) of 0.89, Root Mean Square Error (RMSE) of 2.53 μg/l and Mean Absolute Error (MAE) of 1.02 μg/l was most capable of representing actual Chl-a concentrations. This is attributed to the differential response of the red and blue wavebands to the Chl-a signal. The study is considered more robust than previous studies of Chl-a retrieval, due to the much larger number of images and in situ samples used for model development and validation, as well as the different times of year, water quality zones, and wide range of Chl-a concentrations which were investigated. The robustness of the developed model was also tested by its application to monitoring an extensive red tide event. The results indicate that the developed model is capable of routine monitoring of such algal blooms which frequently occur from late summer to early autumn in Hong Kong and its adjacent coastal waters.

  14. Kinetics of the oxidation of lactose by copper(II) complexed with bipyridyl in alkaline medium using chloro-complex of rhodium(III) in its nano-concentration range as homogeneous catalyst: a spectrophotometric study.

    PubMed

    Kumar Singh, Ashok; Singh, Manjula; Srivastava, Jaya; Rahmani, Shahla

    2012-06-01

    Kinetics of the oxidation of lactose by Cu(II) complexed with bipyridyl have been investigated at 40 °C for the first time spectrophotometrically using Rh(III) chloride as homogeneous catalyst in aqueous alkaline medium in its nano-concentration range. The order of reaction was found to be fractional positive-order, when the concentration of Rh(III) chloride was varied from 0.30×10(-9) M to 6.00×10(-9) M. The reaction shows fractional positive-order kinetics with respect to [lactose] and [OH(-)] and zeroth-order kinetics with respect to [Cu(II)]. The reaction also shows slight increase in the rate by decreasing dielectric constant of the medium and remains unaffected by the change in ionic strength of the medium. The reaction was carried out at four different temperatures and observed values of rate constants were utilized to calculate various activation parameters specially the entropy of activation (ΔS(#)). The species, [RhCl(3)(H(2)O)(2)OH](-), was postulated as the main reactive species of Rh(III) chloride for the oxidation of lactose by Cu(II) in alkaline medium. On the basis of kinetic and equivalence studies together with spectrophotometric information for the formation of a complex, [formula see text] the most appropriate mechanism for the aforesaid reaction has been proposed. Support to the proposed mechanism was also given by the observed activation parameters and multiple regression analysis. Sodium salts of formic acid, arabinonic acid and lyxonic acid were identified as the main oxidation products of the reaction under investigation. PMID:22541300

  15. Early Decreases in α-Fetoprotein and Des-γ-carboxy Prothrombin Predict the Antitumor Effects of Hepatic Transarterial Infusion Chemotherapy with Cisplatin (CDDP) Powder in Patients with Advanced Hepatocellular Carcinoma.

    PubMed

    Hatanaka, Takeshi; Kakizaki, Satoru; Shimada, Yasushi; Takizawa, Daichi; Katakai, Kenji; Yamazaki, Yuichi; Sato, Ken; Kusano, Motoyasu; Yamada, Masanobu

    2016-01-01

    Objective We retrospectively investigated the relationship between the tumor response and serial changes in α-fetoprotein (AFP) and des-γ-carboxy prothrombin (DCP) during hepatic arterial infusion of a cisplatin powder formulation (CDDP powder) in patients with advanced hepatocellular carcinoma (HCC). Methods Seventy-six advanced HCC patients were analyzed. All HCC patients received high-concentration cisplatin (1.43 mg/mL) via the haptic artery at a dose of 65 mg/m(2). AFP and DCP were measured at baseline and four to eight weeks after treatment, and the antitumor responses were evaluated according to the response evaluation criteria in solid tumours (RECIST) criteria after one or two courses of treatment. The patients were classified into two groups, a decreased group and a non-decreased group, according to the change in the serum levels of AFP and DCP at four to eight weeks compared to baseline. Results The response to treatment of the decreased group (n=16) and non-decreased group (n=60) was complete response/partial response/stable disease/progressive disease (CR/PR/SD/PD) in 4/4/5/3 and 1/11/8/40 patients, respectively. The response rate and disease control rate of the decreased group were significantly higher than those of the non-decreased group (p=0.016 and p<0.001, respectively). The median survival time (MST) of the decreased/non-decreased groups were 25.9/10.6 months, respectively. The cumulative survival rates for the decreased group were significantly higher than those of the non-decreased group (p=0.042). In the multivariate analysis, vascular invasion and the decreased group were significant factors that affected the therapeutic efficacy. Conclusion A decrease in the levels of AFP and DCP after the first treatment with CDDP powder is a good predictor for the antitumor effect and the prognosis. PMID:27522991

  16. PVDF-ErGO-GRC electrode: A single setup electrochemical system for separation, pre-concentration and detection of lead ions in complex aqueous samples.

    PubMed

    Hamsawahini, Kunashegaran; Sathishkumar, Palanivel; Ahamad, Rahmalan; Yusoff, Abdull Rahim Mohd

    2016-02-01

    An effective electrode was developed based on electromembrane extraction (EME) and square wave voltammetry (SWV) for simultaneous separation, pre-concentration and determination of lead (II) (Pb(II)) ions in complex aqueous samples. Electrochemically reduced graphene oxide-graphite reinforced carbon (ErGO-GRC) was utilized in conjunction with the SWV. Pb(II) ions were extracted from an aqueous sample solution into an acidic acceptor phase (1M HCl) in the lumen of the polyvinylidene fluoride (PVDF) membrane bag by the application of voltage of maximum 6 V across the supported liquid membrane (SLM), consisting of organic solvent and di-(2-ethylhexyl)phosphoric acid (D2EHPA). The parameters affecting the EME were optimized for Pb(II) ions. The optimum EME conditions were found to be 20% D2EHPA in 1-octanol impregnated in the wall of PVDF membrane (PVDF17) as the SLM, extraction time of 20 min, pH of sample solution of 8 and a voltage of 5 V. The PVDF-ErGO-GRC electrode system attained enrichment factors of 40 times and 80% of extraction with relative standard deviations (n=5) of 8.3%. Good linearity ranging from 0.25 to 2 nM with coefficients correlation of 0.999 was obtained. The Pb(II) ions detection limit of PVDF-ErGO-GRC electrode was found to be 0.09 nM. The newly developed single setup electrochemical system was applied to complex aqueous samples such as tap, river and sea water to evaluate the feasibility of the method for applications. PMID:26653429

  17. Estimating hourly benzene concentrations in a highly-complex topographical environment in northern Spain using RAMS and the CALPUFF modeling system

    NASA Astrophysics Data System (ADS)

    Valdenebro, Verónica; Sáez de Cámara, Estíbaliz; Gangoiti, Gotzon; Alonso, Lucio; García, José Antonio; Ilardia, Juan Luis; González, Nerea

    2013-04-01

    The RAMS-CALMET-CALPUFF modeling system together with observations has been used to analyse the hourly benzene impacts of a coke plant in a nearby urban area in a region of very complex topography (a mountainous region near the coast) in northern Spain. The air flow in this region is strongly influenced by the local topography and, specially under anticyclonic conditions, important daily changes in stability, wind velocity and wind direction occur almost every day, which directly affect the dispersion of pollutants in the area. The aim of this study was to set up a methodology suitable for dispersion studies in very complex areas, where pollutants dynamics is highly affected by mesoscale meteorological processes. Two ten-day periods have been modeled. High spatio-temporal resolution meteorological simulations have been performed with the non-hydrostatic mesoscale meteorological model RAMS. A configuration of four nested grids has been used. 4D assimilation has been performed using NCEP and ERA-Interim data. The RAMS meteorological output has been downscaled from a 1 km to a 250 m resolution with the CALMET diagnostic model. Observational meteorological data have been assimilated into CALMET. The results of the meteorological simulations have been validated both against data recorded by a network of surface stations and by a wind profiler radar (WPR) located near the coast. The already validated meteorological fields have been input into the CALPUFF nonsteady-state puff dispersion model. For the dispersion simulations, benzene emission data have been obtained from the Spanish E-PRTR Register. Predicted impacts have also been compared with observations. Comparisons of the RAMS simulated wind fields against the WPR profiles have revealed inaccurate NCEP reanalysis data for one of the simulated periods. Initialization with ECMWF-Interim data have improved the results. The main flows that affect dispersion in the area have been mostly well captured by the modeling

  18. Coagulation factor concentrate-based therapy for remote damage control resuscitation (RDCR): a reasonable alternative?

    PubMed

    Maegele, Marc

    2016-04-01

    The concept of remote damage control resuscitation (RDCR) is still in its infancy and there is significant work to be done to improve outcomes for patients with life-threatening bleeding secondary to injury. The prehospital phase of resuscitation is critical and if shock and coagulopathy can be rapidly minimized before hospital admission this will very likely reduce morbidity and mortality. The optimum transfusion strategy for these patients is still highly debated and the potential implications of the recently published pragmatic, randomize, optimal platelet, and plasma ratios trial (PROPPR) for RDCR have been reviewed. Identifying the appropriate transfusion strategy is mandatory before adopting prehospital hemostatic resuscitation strategies. An alternative approach is based on the early administration of coagulation factor concentrates combined with the antifibrinolytic tranexamic acid (TXA). The three major components to this approach in the context of RDCR target the following steps to achieve hemostasis: 1) stop (hyper)fibrinolysis; 2) support clot formation; and 3) increase thrombin generation. Strong evidence exists for the use of TXA. The data from the prospective fibrinogen in trauma induced coagulopathy (FIinTIC) study will inform on the prehospital use of fibrinogen in bleeding trauma patients. Deficits in thrombin generation may be addressed by the administration of prothrombin complex concentrates. Handheld point-of-care devices may be able to support and guide the prehospital and remote use of intravenous hemostatic agents including coagulation factor concentrates along with clinical presentation, assessment, and the extent of bleeding. Combinations may even be more effective for bleeding control. More studies are urgently needed. PMID:27100752

  19. Interaction of Hurricane Katrina with Optically Complex Water in the Gulf of Mexico: Interpretation Using Satellite-Derived Inherent Optical Properties and Chlorophyll Concentration

    NASA Astrophysics Data System (ADS)

    Lyon, P. E.; Acker, J.; Hoge, F. E.; Shen, S.; Roffer, M.; Gawlikowski, G.

    2008-12-01

    When Hurricane Katrina passed over southern Florida, Florida Bay and the West Florida Shelf, and into the Gulf of Mexico, empirically derived chl a increases were observed in the Tortugas Gyre circulation feature, and in adjacent waters. Analysis of the empirically derived chl a increase within the gyre has been primarily attributed to initiation of a phytoplankton bloom promoted by nutrients upwelled by Katrina's winds. Detailed analysis of inherent optical properties (IOPs) derived from remotely-sensed radiances, however, indicated the interaction of Katrina with shallow coastal and shelf waters likely entrained waters with higher concentrations of chromophoric dissolved organic matter (CDOM) into the gyre circulation, augmenting the chl a signal. Storm-induced upwelling would also transport optically active CDOM to the surface. Increases in empirically derived chl a in the Florida coastal waters influenced by Katrina's winds were therefore partly due to increased absorption by CDOM. This analysis indicates that elevated empirically derived chl a in hurricane-influenced waters should not be unambiguously attributed to increased phytoplankton productivity, particularly in an optically complex coastal environment.

  20. Thrombin generation, ProC®Global, prothrombin time and activated partial thromboplastin time in thawed plasma stored for seven days and after methylene blue/light pathogen inactivation

    PubMed Central

    Thiele, Thomas; Hron, Gregor; Kellner, Sarah; Wasner, Christina; Westphal, Antje; Warkentin, Theodore E.; Greinacher, Andreas; Selleng, Kathleen

    2016-01-01

    Background Methylene blue pathogen inactivation and storage of thawed plasma both lead to changes in the activity of several clotting factors. We investigated how this translates into a global loss of thrombin generation potential and alterations in the protein C pathway. Materials and methods Fifty apheresis plasma samples were thawed and each divided into three subunits. One subunit was stored for 7 days at 4 °C, one was stored for 7 days at 22 °C and one was stored at 4 °C after methylene blue/light treatment. Thrombin generation parameters, ProC®Global-NR, prothrombin time and activated partial thromboplastin time were assessed on days 0 and 7. Results The velocity of thrombin generation increased significantly after methylene blue treatment (increased thrombin generation rate; time to peak decreased) and decreased after storage (decreased thrombin generation rate and peak thrombin; increased lag time and time to peak). The endogenous thrombin generation potential remained stable after methylene blue treatment and storage at 4 °C. Methylene blue treatment and 7 days of storage at 4 °C activated the protein C pathway, whereas storage at room temperature and storage after methylene blue treatment decreased the functional capacity of the protein C pathway. Prothrombin time and activated partial thromboplastin time showed only modest alterations. Discussion The global clotting capacity of thawed plasma is maintained at 4 °C for 7 days and directly after methylene blue treatment of thawed plasma. Thrombin generation and ProC®Global are useful tools for investigating the impact of pathogen inactivation and storage on the clotting capacity of therapeutic plasma preparations. PMID:26192785

  1. The relationship between factor V Leiden, prothrombin G20210A, and MTHFR mutations and the first major thrombotic episode in polycythemia vera and essential thrombocythemia.

    PubMed

    Trifa, Adrian P; Cucuianu, Andrei; Popp, Radu A; Coadă, Camelia A; Costache, Roxana M; Militaru, Mariela S; Vesa, Ştefan C; Pop, Ioan V

    2014-02-01

    Arterial and venous thrombosis are the most frequent complications in patients with polycythemia vera and essential thrombocythemia. We sought to demonstrate a possible contribution of the factor V Leiden, prothrombin G20210A, and methylenetetrahydrofolate reductase (MTHFR) 677 C > T and 1298 A > C mutations to the thrombotic risk in patients with polycythemia vera and essential thrombocythemia along with other biological features of these patients. We included 86 patients with polycythemia vera, of which 34 (39.5 %) had major thrombosis and 95 patients with essential thrombocythemia, of which 22 (23.1 %) had major thrombosis. In the whole cohort of patients, only the factor V Leiden mutation was significantly associated with both arterial and venous thrombosis in univariate and multivariate analysis (odds ratio (OR) = 4.3; 95 % confidence interval (CI) = 1.5-12.5; p = 0.008 and OR = 4.3; 95 % CI = 1.2-15.9; p = 0.02, respectively). Other factors significantly associated with thrombosis in both univariate and multivariate analysis were male sex (OR = 2.8, 95 % CI = 1.4-5.4, p = 0.002 and OR = 3.5, 95 % CI = 1.6-7.6, p = 0.002, respectively) and the JAK2 V617F mutation (OR = 5.5, 95 % CI = 2.1-15, p = 0.0001 and OR = 6.9, 95 % CI = 2.2-21.2, p = 0.001, respectively). In conclusion, among the four mutations analyzed (factor V Leiden, prothrombin G20210A, and MTHFR 677 C > T and 1298 A > C), only factor V Leiden is a major contributor to thrombosis in polycythemia vera and essential thrombocythemia. PMID:23828072

  2. Structure–activity relationships of the human prothrombin kringle-2 peptide derivative NSA9: anti-proliferative activity and cellular internalization

    PubMed Central

    Hwang, Hyun Sook; Kim, Dong Won; Kim, Soung Soo

    2006-01-01

    The human prothrombin kringle-2 protein inhibits angiogenesis and LLC (Lewis lung carcinoma) growth and metastasis in mice. Additionally, the NSA9 peptide (NSAVQLVEN) derived from human prothrombin kringle-2 has been reported to inhibit the proliferation of BCE (bovine capillary endothelial) cells and CAM (chorioallantoic membrane) angiogenesis. In the present study, we examined the structure–activity relationships of the NSA9 peptide in inhibiting the proliferation of endothelial cells lines e.g. BCE and HUVE (human umbilical vein endothelial). N- or C-terminal truncated derivatives and reverse sequence analogues of NSA9 were prepared and their anti-proliferative activities were assessed using the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide] assay. This cell proliferation assay demonstrated that both the N-terminal region and sequence orientation of NSA9 are important for inhibiting the proliferation of endothelial cells. In particular 2 C-terminal truncation derivatives of NSA9 [NSA7 (NSAVQLV) and NSA8 (NSAVQLVE)] inhibited cellular proliferation to a greater extent than did NSA9. The heptapeptide NSA7, was found to be more potent than NSA9 in inhibiting CAM angiogenesis, and tubular formation and migration of HUVE cells. In addition NSA9, NSA8 and NSA7 peptides exhibited considerable inhibitory effects on the proliferation of tumour cells such as B16F10 (murine melanoma), LLC and L929 (murine fibroblast). Also, cellular internalization studies demonstrated that NSA7 was internalized into both endothelial and tumour cells more easily than was NSA9. In conclusion, these results suggest that NSA7, residing within the full sequence of NSA9, contains the required sequence for anti-proliferative activity and cellular internalization. PMID:16390327

  3. Trauma-Induced Coagulopathy Is Associated with a Complex Inflammatory Response in the Rat.

    PubMed

    Darlington, Daniel N; Gonzales, Mary D; Craig, Teresa; Dubick, Michael A; Cap, Andrew P; Schwacha, Martin G

    2015-08-01

    Severe trauma can lead to a coagulopathy in patients, which is associated with increased mortality. We developed a rat polytrauma model that demonstrates a similar progression of coagulopathy. Because coagulation is influenced by changes in inflammation, and this interrelationship is poorly understood, we have studied the progression of inflammation, and its correlation with coagulation, in this rat model of severe polytrauma. Sprague-Dawley rats were anesthetized with isoflurane. Polytrauma was induced by damaging 10 cm of small intestines, right and medial liver lobes, right leg skeletal muscle, femur fracture, and hemorrhaging 40% of blood volume. No resuscitation was given. Polytrauma and hemorrhage resulted in a significant decrease in the number of lymphocytes and an increase in monocytes and granulocytes. There was an increase in plasma proinflammatory cytokines: tumor necrosis factor α (40×), interleukin (IL)-6 (20×), IL-1β (16×), IL-17 (15×), interferon γ (10×), IL-1α (8×) and IL-12p70 (5×); anti-inflammatory cytokines: IL-10 (100×), IL-13 (16×), and IL-4 (5×); chemokines: growth-regulated protein/keratinocyte chemoattractant (30×), macrophage inflammatory protein 3α (10×), regulated and normal T-cell expressed and secreted (3×); and growth factors: vascular endothelial growth factor (5×), granulocyte macrophage colony-stimulating factor (6×), macrophage colony-stimulating factor (3×), granulocyte colony-stimulating factor (2×), and IL-5 (3×). There was a strong and significant correlation between prothrombin time, activated partial thromboplastin time, fibrinogen, and fibrin monomer concentration, and many cytokines. Polytrauma with hemorrhage is associated with a coagulopathy and a complex inflammatory response consisting of a concurrent rise in both proinflammatory and anti-inflammatory cytokines. The rise in plasma concentrations of chemokines and growth factors likely contribute to the mobilization of monocytes and granulocytes

  4. Impact of experimental haemodilution on platelet function, thrombin generation and clot firmness: effects of different coagulation factor concentrates

    PubMed Central

    Caballo, Carolina; Escolar, Gines; Diaz-Ricart, Maribel; Lopez-Vílchez, Irene; Lozano, Miguel; Cid, Joan; Pino, Marcos; Beltrán, Joan; Basora, Misericordia; Pereira, Arturo; Galan, Ana M.

    2013-01-01

    Background Haemodilution during resuscitation after massive haemorrhage may worsen the coagulopathy and perpetuate bleeding. Materials and methods Blood samples from healthy donors were diluted (30 and-60%) using crystalloids (saline, Ringer’s lactate, PlasmalyteTM) or colloids (6% hydroxyethylstarch [HES130/0.4], 5% human albumin, and gelatin). The effects of haemodilution on platelet adhesion (Impact R), thrombin generation (TG), and thromboelastometry (TEM) parameters were analysed as were the effects of fibrinogen, prothrombin complex concentrates (PCC), activated recombinant factor VII (FVIIa), and cryoprecipates on haemodilution. Results Platelet interactions was already significantly reduced at 30% haemodilution. Platelet reactivity was not improved by addition of any of the concentrates tested. A decrease in TG and marked alterations of TEM parameters were noted at 60% haemodilution. HES130/0.4 was the expander with the most deleterious action. TG was significantly enhanced by PCC whereas rFVIIa only caused a mild acceleration of TG initiation. Fibrinogen restored the alterations of TEM parameters caused by haemodilution including those caused by HES 130/0.4. Cryoprecipitates significantly improved the alterations caused by haemodilution on TG and TEM parameters; the effects on TG disappeared after ultracentrifugation of the cryoprecipitates. Discussion The haemostatic alterations caused by haemodilution are multifactorial and affect both blood cells and coagulation. In our in vitro approach, HES 130/0.4 had the most deleterious effect on haemostasis parameters. Coagulation factor concentrates did not improve platelet interactions in the Impact R, but did have favourable effects on coagulation parameters measured by TG and TEM. Fibrinogen notably improved TEM parameters without increasing thrombin generation, suggesting that this concentrate may help to preserve blood clotting abilities during haemodilution without enhancing the prothrombotic risk. PMID

  5. Discovery of Novel Nonactive Site Inhibitors of the Prothrombinase Enzyme Complex.

    PubMed

    Kapoor, Karan; McGill, Nicole; Peterson, Cynthia B; Meyers, Harold V; Blackburn, Michael N; Baudry, Jerome

    2016-03-28

    The risk of serious bleeding is a major liability of anticoagulant drugs that are active-site competitive inhibitors targeting the Factor Xa (FXa) prothrombin (PT) binding site. The present work identifies several new classes of small molecule anticoagulants that can act as nonactive site inhibitors of the prothrombinase (PTase) complex composed of FXa and Factor Va (FVa). These new classes of anticoagulants were identified, using a novel agnostic computational approach to identify previously unrecognized binding pockets at the FXa-FVa interface. From about three million docking calculations of 281,128 compounds in a conformational ensemble of FXa heavy chains identified by molecular dynamics (MD) simulations, 97 compounds and their structural analogues were selected for experimental validation, through a series of inhibition assays. The compound selection was based on their predicted binding affinities to FXa and their ability to successfully bind to multiple protein conformations while showing selectivity for particular binding sites at the FXa/FVa interface. From these, thirty-one (31) compounds were experimentally identified as nonactive site inhibitors. Concentration-based assays further identified 10 compounds represented by four small-molecule families of inhibitors that achieve dose-independent partial inhibition of PTase activity in a nonactive site-dependent and self-limiting mechanism. Several compounds were identified for their ability to bind to protein conformations only seen during MD, highlighting the importance of accounting for protein flexibility in structure-based drug discovery approaches. PMID:26848511

  6. Concentrator Systems

    NASA Astrophysics Data System (ADS)

    Luque-Heredia, Ignacio; Luque, Antonio

    2015-10-01

    The following sections are included: * Introduction * The early development of CPV * Concentrator solar cells * Optics for photovoltaic concentrators * Photovoltaic concentration modules * Tracking systems for photovoltaic concentration * High-concentration systems * Rating and performance * Cost considerations * Conclusions * References

  7. Concentrations of 222Rn, Its Short-Lived Daughters And 212Pb And Their Ratios Under Complex Atmospheric Conditions And Topography

    NASA Astrophysics Data System (ADS)

    Kataoka, Toshio; Yunoki, Eiji; Shimizu, Mitsuo; Mori, Tadashige; Tsukamoto, Osamu; Takahashi, Satoshi; Fudeyasu, Hironori; Ohashi, Yukitaka; Sahashi, Ken; Maitani, Toshihiko; Miyashita, Koh'ichi; Iwata, Toru; Sasaki, Takayuki; Fujikawa, Yoko; Kudo, Akira; Shaw, Roger H.

    Atmospheric activity concentrations of 212Pb and short-lived 222Rndaughters, together with meteorological elements, have been observed continuously atthree sites at Kamisaibara Village in Japan. In addition, atmospheric activity concentrationof 222Rn, equilibrium-equivalent concentration of 222Rn and conditionsof the lower atmosphere were observed for three intensive observation periods at Akawase,one of the three sites in Kamisaibara Village. The equilibrium-equivalent concentration of222Rn is almost the same as the atmospheric activity concentration of short-lived222Rn daughters.The activity concentrations of 212Pb and the short-lived 222Rn daughtersand their ratio were low in the daytime owing to convective mixing, and high at nightowing to the surface-based inversion during periods of no precipitation. Their variationshave several patterns corresponding to the scale of the drainage wind or weak mixing.

  8. Massive pulmonary embolism associated with Factor V Leiden, prothrombin, and methylenetetrahydrofolate reductase gene mutations in a young patient on oral contraceptive pills: a case report.

    PubMed

    Charafeddine, Khalil M; Mahfouz, Rami A; Ibrahim, Georges Y; Taher, Ali T; Hoballah, Jamal J; Taha, Assad M

    2010-10-01

    Factor V Leiden (Factor V G1691A), prothrombin gene mutation G20210A, and homozygous C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene are known to predispose venous thromboembolism (VTE). We present herein a rare case of a young woman heterozygous for these mutations and taking oral contraceptive pills for less than 2 months, diagnosed to have massive deep venous thrombosis and bilateral pulmonary embolism. The patient was managed for 10 days in the hospital and discharged home on oral anticoagulants. This case suggests that screening for these factors in people with family history of thrombosis and in relatives of patients with these mutations is highly recommended to prevent fatal consequences. In addition, a new guideline for treatment and prophylaxis with anticoagulant for these patients and others who are at risk of developing VTE (American College of Chest Physicians [ACCP] guidelines-Chest 2008) has been published recently. Our recommendation is to promote for the internationally published algorithms through their application, where necessary, to prevent any future thrombotic morbidity or mortality incidents. PMID:19520679

  9. The Predictive Power of Serum α-Fetoprotein and Des-γ-Carboxy Prothrombin for Survival Varies by Tumor Size in Hepatocellular Carcinoma.

    PubMed

    Tsugawa, Daisuke; Fukumoto, Takumi; Kido, Masahiro; Takebe, Atsushi; Tanaka, Motofumi; Kuramitsu, Kaori; Matsumoto, Ippei; Ajiki, Tetsuo; Koyama, Tatsuki; Ku, Yonson

    2016-01-01

    Alpha-fetoprotein (AFP) and des-γ-carboxy prothrombin (DCP) are frequently used as tumor markers in hepatocellular carcinoma (HCC). The authors hypothesized different patient populations with varying tumor sizes would influence the predictive power of tumor markers for survival in HCC patients. The authors investigated the influence of tumor size on predictive powers of AFP and DCP. 181 patients underwent hepatectomy for HCC from 2003 to 2008 at Kobe University Hospital. Tumor markers were measured before and at 1 month post-hepatectomy. The Cox proportional-hazards model revealed that preoperative serum AFP was associated with survival; its effects depended on tumor size. Hazard ratios (HRs) for preoperative AFP were maximum for medium-sized HCC, and for DCP, HRs were maximum in small-sized tumors. Post-hepatectomy, both tumor markers were associated with survival, revealing significant interactions with tumor size. HRs for postoperative AFP were greater than 1 for relatively wide range tumors (3-11 cm). HRs for postoperative DCP increased with tumor size, with a strong prognostic predictive power for tumors >5 cm. The predictive power of serum tumor markers varied by tumor size in HCC patients. By selecting the appropriate tumor marker, its predictive power can be improved. PMID:27363395

  10. The human prothrombin kringle-2 derived peptide, NSA9, is internalized into bovine capillary endothelial cells through endocytosis and energy-dependent pathways

    SciTech Connect

    Hwang, Hyun Sook; Kim, Soung Soo . E-mail: kimss518@yonsei.ac.kr

    2005-09-23

    Human prothrombin kringle-2 and its partial peptide, NSA9 (NSAVQLVEN), have been reported to have potent anti-angiogenic activities. Here, the internalization mechanism of NSA9 into bovine capillary endothelial (BCE) cells was examined using lactate dehydrogenase (LDH) release assay, fluorescence microscopy, and flow cytometry. LDH release assay results suggested that the integrity of the BCE cell membrane was unaffected by NSA9. Fluorescence microscopy indicated that internalized NSA9 was localized in the cytoplasm around the nucleus, and showed a punctuated fluorescence pattern, which is indicative of endocytic vesicles. Also, the cellular internalization of NSA9 is significantly inhibited by depletion of the cellular ATP pool, endocytosis inhibitors such as chloroquine and nocodazole, and incubation at low temperature (4 deg C). In addition, the anti-proliferative activity of NSA9 against BCE cells was diminished in the presence of endocytosis or metabolic inhibitors. In conclusion, these results strongly suggest that NSA9 might exert its anti-proliferative activity through internalization into BCE cells by endocytosis and energy-dependent pathways.

  11. Association between the thrombophilic polymorphisms MTHFR C677T, Factor V Leiden, and prothrombin G20210A and recurrent miscarriage in Brazilian women.

    PubMed

    Gonçalves, R O; Fraga, L R; Santos, W V B; Carvalho, A F L; Veloso Cerqueira, B A V; Sarno, M; Toralles, M B P; Vieira, M J; Dutra, C G; Schüler-Faccini, L; Sanseverino, M T V; Gonçalves, M S; Vianna, F S L; Costa, O L N

    2016-01-01

    Some cases of recurrent first trimester miscarriage have a thrombotic etiology. The aim of this study was to investigate the prevalence of the most common thrombophilic mutations - factor V (FV) Leiden G1691A (FVL), prothrombin (FII) G20210A, and methylenetetrahydrofolate reductase (MTHFR) C677T - in women with recurrent miscarriages. In this case-control study, we included 137 women with two or more consecutive first-trimester miscarriages (£12 weeks of gestation) and 100 healthy women with no history of pregnancy loss, and with at least one living child. DNA was extracted from the patient samples, and the relevant genes (FVL, FII, and MTHFR) were amplified by PCR, followed by restriction fragment length polymorphism, to assess the polymorphisms in these genes. The allelic frequencies of polymorphisms were not significantly different between the case and control groups. Polymorphisms in the MTHFR, FVL, and FII genes were not associated with recurrent miscarriage during the first trimester of pregnancy in Brazilian women (P = 0.479; P = 0.491 and P = 0.107, respectively). However, the etiologic identification of genetic factors is important for genetic counseling. PMID:27525841

  12. Induction of microglial toll-like receptor 4 by prothrombin kringle-2: a potential pathogenic mechanism in Parkinson’s disease

    PubMed Central

    Shin, Won-Ho; Jeon, Min-Tae; Leem, Eunju; Won, So-Yoon; Jeong, Kyoung Hoon; Park, Sang-Joon; McLean, Catriona; Lee, Sung Joong; Jin, Byung Kwan; Jung, Un Ju; Kim, Sang Ryoung

    2015-01-01

    Microglia-mediated neuroinflammation may play an important role in the initiation and progression of dopaminergic (DA) neurodegeneration in Parkinson’s disease (PD), and toll-like receptor 4 (TLR4) is essential for the activation of microglia in the adult brain. However, it is still unclear whether patients with PD exhibit an increase in TLR4 expression in the brain, and whether there is a correlation between the levels of prothrombin kringle-2 (pKr-2) and microglial TLR4. In the present study, we first observed that the levels of pKr-2 and microglial TLR4 were increased in the substantia nigra (SN) of patients with PD. In rat and mouse brains, intranigral injection of pKr-2, which is not directly toxic to neurons, led to the disruption of nigrostriatal DA projections. Moreover, microglial TLR4 was upregulated in the rat SN and in cultures of the BV-2 microglial cell line after pKr-2 treatment. In TLR4-deficient mice, pKr-2-induced microglial activation was suppressed compared with wild-type mice, resulting in attenuated neurotoxicity. Therefore, our results suggest that pKr-2 may be a pathogenic factor in PD, and that the inhibition of pKr-2-induced microglial TLR4 may be protective against degeneration of the nigrostriatal DA system in vivo. PMID:26440368

  13. Spectrophotometric determination of arsenic by molybdenum blue method in zinc-lead concentrates and related smelter products after chloroform extraction of iodide complex.

    PubMed

    Rao, C S; Rajan, S C; Rao, N V

    1993-05-01

    The most popular and widely applied method for determination of arsenic in ore concentrates is by spectrophotometry of arsenomolybdic acid reduced to molybdenum blue. While applying this method, several authors have developed procedures which varied in the decomposition, separation of arsenic and in the final colour development. Data regarding interference from germanium is inadequate. The present paper describes a procedure, which combines the best features of the previous procedures and is simple, less time consuming and interference-free compared to earlier procedures. This method has been applied to zinc-lead concentrates and related smelter products. PMID:18965681

  14. Assessment of reproductive effects on complex mixtures of disinfection by-products in a multigenerational rat bioassay of drinking water concentrates

    EPA Science Inventory

    To address concerns raised by epidemiology studies, we conducted a multigenerational reproductive toxicity study in rats using a “whole” mixture of drinking water disinfection by-products (DBPs). Raw water was concentrated ~130 fold, chlorinated, and provided as drinking water to...

  15. Assessment of Reproductive Effects of Complex Mixtures of Disinfection By-Products in a Multi-Generational Rat Bioassay of Drinking Water Concentrates - Monterey

    EPA Science Inventory

    To address concerns raised by epidemiology studies, we conducted a multigenerational reproductive toxicity study in rats using a “whole” mixture of drinking water disinfection by-products (DBPs). Raw water was concentrated ~130 fold, chlorinated, and provided as drinking water to...

  16. [THE INFLUENCE OF A COMBINATION OF MODERN DRUGS NUCLEINAT AND ALFAGIN ON THE CONCENTRATION OF CIRCULATING IMMUNE COMPLEXES AND THEIR MOLECULAR COMPOSITION IN THE SERUM OF PATIENTS WITH IRRITABLE BOWEL SYNDROME ON THE BACKGROUND OF NEUROCIRCULATORY DYSTONIA IN COMPLEX MEDICAL REHABILITATION].

    PubMed

    Krivulya, I G; Teryshin, V A; Sotskaya, Y A

    2015-01-01

    The effect of the combination nucleinat and alfagin in a complex of medical rehabilitation at the level of circulating immune complexes (CIC) in serum of patients and their molecular composition with irritable bowel syndrome (IBS), against neurocirculatory dystonia (NeD). It is established that the combination of nucleinat and alfagin in medical rehabilitation of patients with this comorbid disorders contributes to the normalization of the total concentration of the CEC and their molecular composition, which indicates the validity of the application of the pathogenesis combinations of drugs in complex medical rehabilitation of patients with lBS against NCD. PMID:27491155

  17. Alpha-fetoprotein and des-gamma-carboxy-prothrombin at twenty-four weeks after interferon-based therapy predict hepatocellular carcinoma development

    PubMed Central

    Shakado, Satoshi; Sakisaka, Shotaro; Chayama, Kazuaki; Okanoue, Takeshi; Toyoda, Joji; Izumi, Namiki; Matsumoto, Akihiro; Takehara, Tetsuo; Ido, Akio; Hiasa, Yoichi; Yoshioka, Kentaro; Nomura, Hideyuki; Ueno, Yoshiyuki; Seike, Masataka; Kumada, Hiromitsu

    2015-01-01

    AIM: To investigate risk factors for development of hepatocellular carcinoma (HCC) in patients with hepatitis C virus-related liver cirrhosis (LC-C). METHODS: To evaluate the relationship between clinical factors including virological response and the development of HCC in patients with LC-C treated with interferon (IFN) and ribavirin, we conducted a multicenter, retrospective study in 14 hospitals in Japan. All patients had compensated LC-C with clinical or histological data available. HCC was diagnosed by the presence of typical hypervascular characteristics on computed tomography and/or magnetic resonance imaging. RESULTS: HCC was diagnosis in 50 (21.6%) of 231 LC-C patients during a median observation period of 3.8 years after IFN and ribavirin therapy. Patients who developed HCC were older (P = 0.018) and had higher serum levels of pretreatment alpha-fetoprotein (AFP) (P = 0.038). Multivariate analysis revealed the following independent risk factors for HCC development: history of treatment for HCC [P < 0.001, odds ratio (OR) = 15.27, 95%CI: 4.98-59.51], AFP levels of ≥ 10 ng/mL (P = 0.009, OR = 3.89, 95%CI: 1.38-11.94), and des-γ-carboxy prothrombin (DCP) levels of ≥ 40 mAU/mL at 24 wk after the completion of IFN and ribavirin therapy (P < 0.001, OR = 24.43, 95%CI: 4.11-238.67). CONCLUSION: We suggested that the elevation of AFP and DCP levels at 24 wk after the completion of IFN and ribavirin therapy were strongly associated with the incidence of HCC irrespective of virological response among Japanese LC-C patients. PMID:26644819

  18. Diagnostic Evaluation of Des-Gamma-Carboxy Prothrombin versus α-Fetoprotein for Hepatitis B Virus-Related Hepatocellular Carcinoma in China: A Large-Scale, Multicentre Study.

    PubMed

    Ji, Jun; Wang, Hao; Li, Yan; Zheng, Lei; Yin, Yuepeng; Zou, Zhenzhen; Zhou, Feiguo; Zhou, Weiping; Shen, Feng; Gao, Chunfang

    2016-01-01

    An efficient serum marker for hepatocellular carcinoma (HCC) is currently lacking and requires intensive exploration. We aimed to evaluate the performance of des-gamma-carboxy prothrombin (DCP) for identifying hepatitis B virus-related HCC in a large, multicentre study in China. A total of 1034 subjects in three cohorts (A, B, and C) including HCC and various non-HCC controls were enrolled from 4 academic medical centers in China from January 2011 to February 2014. Blind parallel detections were conducted for DCP and AFP. The area under the receiver operating characteristic curve (AUC) was used to evaluate the diagnostic efficacies. In cohort A, which comprised 521 subjects, including patients with HCC, liver metastasis, liver cirrhosis (LC), and liver hemangiomas as well as healthy controls (HCs), the accuracy of DCP for distinguishing HCC from various controls was 6.2-9.7% higher than that of AFP. In cohort B, which comprised 447 subjects, including patients with HCC, LC, and chronic hepatitis B as well as HC, the accuracy of DCP was further elevated (12.3-20.67% higher than that of AFP). The superiority of DCP to AFP was more profound in the surveillance of early HCC [AUC 0.837 (95% CI: 0.771-0.903) vs. 0.650 (0.555-0.745)] and AFP-negative HCC [AUC: 0.856 (0.798-0.914)] and in discriminating HCC from LC (accuracy: 92.9% vs.64.71%). Higher DCP levels were associated with worse clinical behaviors and shorter disease-free survival. DCP not only is complementary to AFP in identifying AFP-negative HCC and in excluding AFP-positive non-HCC (liver cirrhosis), but also demonstrates improved performance in HCC surveillance, early diagnosis, treatment response and recurrence monitoring in the HBV-related population. PMID:27070780

  19. Diagnostic Evaluation of Des-Gamma-Carboxy Prothrombin versus α-Fetoprotein for Hepatitis B Virus-Related Hepatocellular Carcinoma in China: A Large-Scale, Multicentre Study

    PubMed Central

    Zheng, Lei; Yin, Yuepeng; Zou, Zhenzhen; Zhou, Feiguo; Zhou, Weiping; Shen, Feng; Gao, Chunfang

    2016-01-01

    An efficient serum marker for hepatocellular carcinoma (HCC) is currently lacking and requires intensive exploration. We aimed to evaluate the performance of des-gamma-carboxy prothrombin (DCP) for identifying hepatitis B virus-related HCC in a large, multicentre study in China. A total of 1034 subjects in three cohorts (A, B, and C) including HCC and various non-HCC controls were enrolled from 4 academic medical centers in China from January 2011 to February 2014. Blind parallel detections were conducted for DCP and AFP. The area under the receiver operating characteristic curve (AUC) was used to evaluate the diagnostic efficacies. In cohort A, which comprised 521 subjects, including patients with HCC, liver metastasis, liver cirrhosis (LC), and liver hemangiomas as well as healthy controls (HCs), the accuracy of DCP for distinguishing HCC from various controls was 6.2–9.7% higher than that of AFP. In cohort B, which comprised 447 subjects, including patients with HCC, LC, and chronic hepatitis B as well as HC, the accuracy of DCP was further elevated (12.3–20.67% higher than that of AFP). The superiority of DCP to AFP was more profound in the surveillance of early HCC [AUC 0.837 (95% CI: 0.771–0.903) vs. 0.650 (0.555–0.745)] and AFP-negative HCC [AUC: 0.856 (0.798–0.914)] and in discriminating HCC from LC (accuracy: 92.9% vs.64.71%). Higher DCP levels were associated with worse clinical behaviors and shorter disease-free survival. DCP not only is complementary to AFP in identifying AFP-negative HCC and in excluding AFP-positive non-HCC (liver cirrhosis), but also demonstrates improved performance in HCC surveillance, early diagnosis, treatment response and recurrence monitoring in the HBV-related population. PMID:27070780

  20. An evaluation of patient self-testing competency of prothrombin time for managing anticoagulation: pre-randomization results of VA Cooperative Study #481--The Home INR Study (THINRS).

    PubMed

    Dolor, Rowena J; Ruybalid, R Lynne; Uyeda, Lauren; Edson, Robert G; Phibbs, Ciaran; Vertrees, Julia E; Shih, Mei-Chiung; Jacobson, Alan K; Matchar, David B

    2010-10-01

    Prior studies suggest patient self-testing (PST) of prothrombin time (PT) can improve the quality of anticoagulation (AC) and reduce complications (e.g., bleeding and thromboembolic events). "The Home INR Study" (THINRS) compared AC management with frequent PST using a home monitoring device to high-quality AC management (HQACM) with clinic-based monitoring on major health outcomes. A key clinical and policy question is whether and which patients can successfully use such devices. We report the results of Part 1 of THINRS in which patients and caregivers were evaluated for their ability to perform PST. Study-eligible patients (n = 3643) were trained to use the home monitoring device and evaluated after 2-4 weeks for PST competency. Information about demographics, medical history, warfarin use, medications, plus measures of numeracy, literacy, cognition, dexterity, and satisfaction with AC were collected. Approximately 80% (2931 of 3643) of patients trained on PST demonstrated competency; of these, 8% (238) required caregiver assistance. Testers who were not competent to perform PST had higher numbers of practice attempts, higher cuvette wastage, and were less able to perform a fingerstick or obtain blood for the cuvette in a timely fashion. Factors associated with failure to pass PST training included increased age, previous stroke history, poor cognition, and poor manual dexterity. A majority of patients were able to perform PST. Successful home monitoring of PT with a PST device required adequate levels of cognition and manual dexterity. Training a caregiver modestly increased the proportion of patients who can perform PST. PMID:20628787

  1. In the Simian Virus 40 In Vitro Replication System, Start Site Selection by the Polymerase α-Primase Complex Is Not Significantly Altered by Changes in the Concentration of Ribonucleotides

    PubMed Central

    Purviance, John D.; Prack, Andrea E.; Barbaro, Brett; Bullock, Peter A.

    2001-01-01

    The simian virus 40 (SV40) in vitro replication system was previously used to demonstrate that the human polymerase (Pol) α-primase complex preferentially initiates DNA synthesis at pyrimidine-rich trinucleotide sequences. However, it has been reported that under certain conditions, nucleoside triphosphate (NTP) concentrations play a critical role in determining where eukaryotic primase initiates synthesis. Therefore, we have examined whether increased NTP concentrations alter the template locations at which SV40 replication is initiated. Our studies demonstrate that elevated ribonucleotide concentrations do not significantly alter which template sequences serve as initiation sites. Of considerable interest, the sequences that serve as initiation sites in the SV40 system are similar to those that serve as initiation sites for prokaryotic primases. It is also demonstrated that regardless of the concentration of ribonucleotides present in the reactions, DNA synthesis initiated outside of the core origin. These studies provide additional evidence that the Pol α-primase complex can initiate DNA synthesis only after a considerable amount of single-stranded DNA is generated. PMID:11413306

  2. Metal concentrations in the soils and native plants surrounding the old flotation tailings pond of the copper mining and smelting complex Bor (Serbia).

    PubMed

    Antonijević, M M; Dimitrijević, M D; Milić, S M; Nujkić, M M

    2012-03-01

    In this study concentrations of metals in the native plants and soils surrounding the old flotation tailings pond of the copper mine were determined. It has been established that the soil is heavily contaminated with copper, iron and arsenic, the mean concentrations being 1585.6, 29,462.5 and 171.7 mg kg(-1) respectively. All the plants, except manganese, accumulated metallic elements in concentrations which were either in the range of critical and phytotoxic values (Pb and As) or higher (Zn), and even much higher (Cu and Fe) than these values. Otherwise, the accumulation of Mn, Pb and As was considerably lower than that of Cu, Fe and Zn. In most plants the accumulation of target metals was highest in the root. Several plant species showed high bioaccumulation and translocation factor values, which classify them into species for potential use in phytoextraction. The BCF and TF values determined in Prunus persica were 1.20 and 3.95 for Cu, 1.5 and 6.0 for Zn and 1.96 and 5.44 for Pb. In Saponaria officinalis these values were 2.53 and 1.27 for Zn, and in Juglans regia L. they were 8.76 and 17.75 for Zn. The translocation factor in most plants, for most metals, was higher than one, whereas the highest value was determined in Populus nigra for Zn, amounting to 17.8. Among several tolerant species, the most suitable ones for phytostabilization proved to be Robinia pseudoacacia L. for Zn and Verbascum phlomoides L., Saponaria officinalis and Centaurea jacea L. for Mn, Pb and As. PMID:22314513

  3. Identification of three elicitins and a galactan-based complex polysaccharide from a concentrated culture filtrate of Phytophthora infestans efficient against Pectobacterium atrosepticum.

    PubMed

    Saubeau, Guillaume; Gaillard, Fanny; Legentil, Laurent; Nugier-Chauvin, Caroline; Ferrières, Vincent; Andrivon, Didier; Val, Florence

    2014-01-01

    The induction of plant immunity by Pathogen Associated Molecular Patterns (PAMPs) constitutes a powerful strategy for crop protection. PAMPs indeed induce general defense responses in plants and thus increase plant resistance to pathogens. Phytophthora infestans culture filtrates (CCFs) are known to induce defense responses and decrease the severity of soft rot due to Pectobacterium atrosepticum in potato tubers. The aim of this study was to identify and characterize the active compounds from P. infestans filtrate. The filtrate was fractionated by gel filtration, and the protection effects against P. atrosepticum and the ability to induce PAL activity were tested for each fraction. The fraction active in protection (F1) also induced PAL activity, as did the whole filtrate. Three elicitins (INF1, INF4 and INF5) were identified in F1b, subfraction of F1, by MALDI-TOF-MS and MS/MS analyses. However, deproteinized F1b still showed biological activity against the bacterium, revealing the presence of an additional active compound. GC-MS analyses of the deproteinized fraction highlighted the presence of a galactan-based complex polysaccharide. These experiments demonstrate that the biological activity of the CCF against P. atrosepticum results from a combined action of three elicitins and a complex polysaccharide, probably through the activation of general defense responses. PMID:25264828

  4. Incorporation of dithiooxamide as a complexing agent into cellulose for the removal and pre-concentration of Cu(II) and Cd(II) ions from natural water samples

    NASA Astrophysics Data System (ADS)

    Jorgetto, A. O.; Silva, R. I. V.; Longo, M. M.; Saeki, M. J.; Padilha, P. M.; Martines, M. A. U.; Rocha, B. P.; Castro, G. R.

    2013-01-01

    The present study describes the incorporation of a complexing agent, dithiooxamide, into microcrystalline cellulose for use in the pre-concentration of Cu(II) and Cd(II) ions from aqueous samples. The FTIR spectrum of the adsorbent exhibited an absorption band in the region of 800 cm-1, which confirmed the binding of the silylating agent to the matrix. Elemental analysis indicated the amount of 0.150 mmol g-1 of the complexing agent. The adsorption data were fit to the modified Langmuir equation, and the maximum amount of metal species extracted from the solution, Ns, was determined to be 0.058 and 0.072 mmol g-1 for Cu(II) and Cd(II), respectively. The covering fraction ϕ, which was 0.39 and 0.48 for Cu(II) and Cd(II), respectively, was used to estimate a 1:2 (metal:ligand) ratio in the formed complex, and a binding model was proposed based on this information. The adsorbent was applied in the pre-concentration of natural water samples and exhibited an enrichment factor of approximately 50-fold for the species studied, which enabled its use in the analysis of trace metals in aqueous samples. The system was validated by the analysis of certified standard (1643e), and the adsorbent was stable for more than 20 cycles, thus enabling its safe reutilization.

  5. Laboratory evaluation of anti-phospholipid syndrome: a preliminary prospective study of phosphatidylserine/prothrombin antibodies in an at-risk patient cohort

    PubMed Central

    Heikal, N M; Jaskowski, T D; Malmberg, E; Lakos, G; Branch, D W; Tebo, A E

    2015-01-01

    Immunoglobulin (Ig)G/IgM autoantibodies to phosphatidylserine/prothrombin (aPS/PT) were evaluated individually and in combination with criteria anti-phospholipid (aPL) tests in a prospectively ascertained cohort of patients at risk for anti-phospholipid syndrome (APS). One hundred and sixty (160) consecutive requests for lupus anti-coagulant (LAC) from the University of Utah Health Sciences Center were identified during 8 weeks. Of these, 104 unique patients had additional requests for cardiolipin (aCL) and/or beta2 glycoprotein I (aβ2GPI) IgG and/or IgM; samples were retained and analysed for aPS/PT, aCL and/or aβ2GPI IgG and IgM antibodies. Following testing, a comprehensive chart review was performed and patients categorized according to their clinical diagnosis. Individual and combined sensitivities, specificities, odd ratios (OR), diagnostic accuracy for specific tests or combinations by receiver operating characteristic (ROC), area under the curve (AUC) analyses and correlations between test results were determined. The sensitivities of aPS/PT IgG/IgM (54·6/45·5%) were lower than LAC (81·8%) but higher relative to aCL IgG/IgM (27·3/0%) or aβ2GPI IgG/IgM (27·3/0%). The best correlation between LAC and any aPL test was observed with aPS/PT (P = 0·002). There was no significant difference in the diagnostic accuracies for any panel with LAC: LAC/aβ2GPI IgG/aCL IgG [AUC 0·979, OR 475·4, 95% confidence interval (CI) 23·1–9056·5, P = 0·0001 and LAC/aβ2GPI IgG/aPS/PT IgG or LAC/aPS/PT IgG/aCL IgG (AUC 0·962, OR 265·3, 14·2–4958·2, P = 0·0001). The high correlation between LAC and aPS/PT IgG/IgM in this preliminary study suggest that this marker may be useful in the evaluation of APS. More studies to determine the optimal aPL antibody tests combination are needed. PMID:25522978

  6. Laboratory evaluation of anti-phospholipid syndrome: a preliminary prospective study of phosphatidylserine/prothrombin antibodies in an at-risk patient cohort.

    PubMed

    Heikal, N M; Jaskowski, T D; Malmberg, E; Lakos, G; Branch, D W; Tebo, A E

    2015-05-01

    Immunoglobulin (Ig)G/IgM autoantibodies to phosphatidylserine/prothrombin (aPS/PT) were evaluated individually and in combination with criteria anti-phospholipid (aPL) tests in a prospectively ascertained cohort of patients at risk for anti-phospholipid syndrome (APS). One hundred and sixty (160) consecutive requests for lupus anti-coagulant (LAC) from the University of Utah Health Sciences Center were identified during 8 weeks. Of these, 104 unique patients had additional requests for cardiolipin (aCL) and/or beta2 glycoprotein I (aβ2 GPI) IgG and/or IgM; samples were retained and analysed for aPS/PT, aCL and/or aβ2 GPI IgG and IgM antibodies. Following testing, a comprehensive chart review was performed and patients categorized according to their clinical diagnosis. Individual and combined sensitivities, specificities, odd ratios (OR), diagnostic accuracy for specific tests or combinations by receiver operating characteristic (ROC), area under the curve (AUC) analyses and correlations between test results were determined. The sensitivities of aPS/PT IgG/IgM (54·6/45·5%) were lower than LAC (81·8%) but higher relative to aCL IgG/IgM (27·3/0%) or aβ2 GPI IgG/IgM (27·3/0%). The best correlation between LAC and any aPL test was observed with aPS/PT (P = 0·002). There was no significant difference in the diagnostic accuracies for any panel with LAC: LAC/aβ2 GPI IgG/aCL IgG [AUC 0·979, OR 475·4, 95% confidence interval (CI) 23·1-9056·5, P = 0·0001 and LAC/aβ2 GPI IgG/aPS/PT IgG or LAC/aPS/PT IgG/aCL IgG (AUC 0·962, OR 265·3, 14·2-4958·2, P = 0·0001). The high correlation between LAC and aPS/PT IgG/IgM in this preliminary study suggest that this marker may be useful in the evaluation of APS. More studies to determine the optimal aPL antibody tests combination are needed. PMID:25522978

  7. Sorption behavior of the Pt(II) complex anion on manganese dioxide (δ-MnO2): a model reaction to elucidate the mechanism by which Pt is concentrated into a marine ferromanganese crust

    NASA Astrophysics Data System (ADS)

    Maeno, Mamiko Yamashita; Ohashi, Hironori; Yonezu, Kotaro; Miyazaki, Akane; Okaue, Yoshihiro; Watanabe, Koichiro; Ishida, Tamao; Tokunaga, Makoto; Yokoyama, Takushi

    2016-02-01

    It is difficult to directly investigate the chemical state of Pt in marine ferromanganese crusts (a mixture of hydrous iron(III) oxide and manganese dioxide (δ-MnO2)) because it is present at extremely low concentration levels. This paper attempts to elucidate the mechanism by which Pt is concentrated into marine ferromanganese crust from the Earth's continental crust through ocean water. In this investigation, the sorption behavior of the Pt(II) complex ions on the surface of the δ-MnO2 that is a host of Pt was examined as a model reaction. The δ-MnO2 sorbing Pt was characterized by X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS) to determine the chemical state of the Pt. Hydrolytic Pt(II) complex ions were specifically sorbed above pH 6 by the formation of a Mn-O-Pt bond. XPS spectra and XANES spectra for δ-MnO2 sorbing Pt showed that the sorbed Pt(II) was oxidized to Pt(IV) on δ-MnO2. The extended X-ray absorption fine structure (EXAFS) analysis showed that the coordination structure of Pt sorbed on δ-MnO2 is almost the same as that of the [Pt(OH)6]2- complex ion used as a standard. Therefore, the mechanism for the concentration of Pt in marine ferromanganese crust may be an oxidative substitution (penetration of Pt(IV) into structure of δ-MnO2) by a reduction-oxidation reaction between Pt(II) in [PtCl4-n(OH)n]2- and Mn(IV) in δ-MnO2 through a Mn-O-Pt bond.

  8. Factor Xa dimerization competes with prothrombinase complex formation on platelet-like membrane surfaces.

    PubMed

    Koklic, Tilen; Chattopadhyay, Rima; Majumder, Rinku; Lentz, Barry R

    2015-04-01

    Exposure of phosphatidylserine (PS) molecules on activated platelet membrane surface is a crucial event in blood coagulation. Binding of PS to specific sites on factor Xa (fXa) and factor Va (fVa) promotes their assembly into a complex that enhances proteolysis of prothrombin by approximately 10⁵. Recent studies demonstrate that both soluble PS and PS-containing model membranes promote formation of inactive fXa dimers at 5 mM Ca²⁺. In the present study, we show how competition between fXa dimerization and prothrombinase formation depends on Ca²⁺ and lipid membrane concentrations. We used homo-FRET measurements between fluorescein-E-G-R-chloromethylketone (CK)-Xa [fXa irreversibly inactivated by alkylation of the active site histidine residue with FEGR (FEGR-fXa)] and prothrombinase activity measurements to reveal the balance between fXa dimer formation and fXa-fVa complex formation. Changes in FEGR-fXa dimer homo-FRET with addition of fVa to model-membrane-bound FEGR-fXa unambiguously demonstrated that formation of the FEGR-fXa-fVa complex dissociated the dimer. Quantitative global analysis according to a model for protein interaction equilibria on a surface provided an estimate of a surface constant for fXa dimer dissociation (K(fXa×fXa)(d, σ)) approximately 10-fold lower than K(fXa×fVa)(d,σ) for fXa-fVa complex. Experiments performed using activated platelet-derived microparticles (MPs) showed that competition between fXa dimerization and fXa-fVa complex formation was even more prominent on MPs. In summary, at Ca²⁺ concentrations found in the maturing platelet plug (2-5 mM), fVa can compete fXa off of inactive fXa dimers to significantly amplify thrombin production, both because it releases dimer inhibition and because of its well-known cofactor activity. This suggests a hitherto unanticipated mechanism by which PS-exposing platelet membranes can regulate amplification and propagation of blood coagulation. PMID:25572019

  9. Dendritic cells use macropinocytosis and the mannose receptor to concentrate macromolecules in the major histocompatibility complex class II compartment: downregulation by cytokines and bacterial products.

    PubMed

    Sallusto, F; Cella, M; Danieli, C; Lanzavecchia, A

    1995-08-01

    We have previously demonstrated that human peripheral blood low density mononuclear cells cultured in granulocyte/macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)-4 develop into dendritic cells (DCs) that are extremely efficient in presenting soluble antigens to T cells. To identify the mechanisms responsible for efficient antigen capture, we studied the endocytic capacity of DCs using fluorescein isothiocyanate-dextran, horseradish peroxidase, and lucifer yellow. We found that DCs use two distinct mechanisms for antigen capture. The first is a high level of fluid phase uptake via macropinocytosis. In contrast to what has been found with other cell types, macropinocytosis in DCs is constitutive and allows continuous internalization of large volumes of fluid. The second mechanism of capture is mediated via the mannose receptor (MR), which is expressed at high levels on DCs. At low ligand concentrations, the MR can deliver a large number of ligands to the cell in successive rounds. Thus, while macropinocytosis endows DCs with a high capacity, nonsaturable mechanism for capture of any soluble antigen, the MR gives an extra capacity for antigen capture with some degree of selectivity for non-self molecules. In addition to their high endocytic capacity, DCs from GM-CSF + IL-4-dependent cultures are characterized by the presence of a large intracellular compartment that contains high levels of class II molecules, cathepsin D, and lysosomal-associated membrane protein-1, and is rapidly accessible to endocytic markers. We investigated whether the capacity of DCs to capture and process antigen could be modulated by exogenous stimuli. We found that DCs respond to tumor necrosis factor alpha, CD40 ligand, IL-1, and lipopolysaccharide with a coordinate series of changes that include downregulation of macropinocytosis and Fc receptors, disappearance of the class II compartment, and upregulation of adhesion and costimulatory molecules. These changes occur

  10. Thermodynamic Modeling of Poorly Complexing Metals in Concentrated Electrolyte Solutions: An X-Ray Absorption and UV-Vis Spectroscopic Study of Ni(II) in the NiCl2-MgCl2-H2O System

    PubMed Central

    Zhang, Ning; Brugger, Joël; Etschmann, Barbara; Ngothai, Yung; Zeng, Dewen

    2015-01-01

    Knowledge of the structure and speciation of aqueous Ni(II)-chloride complexes is important for understanding Ni behavior in hydrometallurgical extraction. The effect of concentration on the first-shell structure of Ni(II) in aqueous NiCl2 and NiCl2-MgCl2 solutions was investigated by Ni K edge X-ray absorption (XAS) and UV-Vis spectroscopy at ambient conditions. Both techniques show that no large structural change (e.g., transition from octahedral to tetrahedral-like configuration) occurs. Both methods confirm that the Ni(II) aqua ion (with six coordinated water molecules at RNi-O = 2.07(2) Å) is the dominant species over the whole NiCl2 concentration range. However, XANES, EXAFS and UV-Vis data show subtle changes at high salinity (> 2 mol∙kg-1 NiCl2), which are consistent with the formation of small amounts of the NiCl+ complex (up to 0.44(23) Cl at a Ni-Cl distance of 2.35(2) Å in 5.05 mol∙kg-1 NiCl2) in the pure NiCl2 solutions. At high Cl:Ni ratio in the NiCl2-MgCl2-H2O solutions, small amounts of [NiCl2]0 are also present. We developed a speciation-based mixed-solvent electrolyte (MSE) model to describe activity-composition relationships in NiCl2-MgCl2-H2O solutions, and at the same time predict Ni(II) speciation that is consistent with our XAS and UV-Vis data and with existing literature data up to the solubility limit, resolving a long-standing uncertainty about the role of chloride complexing in this system. PMID:25885410

  11. Effects of combined treatment with complex S. typhimurium antigens and factors stimulating osteogenesis (curettage, BMP-2) on multipotent bone marrow stromal cells and serum concentration of cytokines in CBA mice.

    PubMed

    Gorskaya, Yu F; Danilova, T A; Karyagina, A S; Lunin, V G; Grabko, V I; Bartov, M S; Gromov, A V; Grunina, T M; Soboleva, L A; Shapoval, I M; Nesterenko, V G

    2015-02-01

    The content of multipotent stromal cells (MSC) in the bone marrow and efficiency of their cloning (ECF-MSC) increased by 3 times 1 day after administration of complex S. typhimurium antigens to CBA mice, while the relative content of alkaline phosphatase-positive MSC colonies (marker of osteogenesis; P(+) colonies) decreased from 14% (control) to 3%. After administration of the complex S. typhimurium antigens to CBA mice 3 h after (or 3 h before) curettage or treatment with morphogenetic protein (BMP-2), the content of MSC and ECF-MSC decreased on the next day by ~3 times in comparison with animals receiving antigens alone and approached the control level. The relative content of P(+) colonies increased to 20 and 35%, respectively, in comparison with animals receiving antigens (3%), but was significantly lower than after curettage (34%) or BMP-2 (42%) administration. Expression of IL-1β, IL-6, IL-12, TNF-α, and IFN-γ genes in the primary cultures of stromal bone marrow cells induced by antigen administration was suppressed, while the concentrations of IL-12 and TNF-α in the culture medium sharply decreased after antigen treatment in combination with curettage or BMP-2 administration. Administration of complex S. typhimurium antigens after pretreatment with BMP-2 (3 h before) was associated with a decrease in serum levels of IL-2, IFN-γ, IL-12, and TNF-α in mice receiving BMP-2+S. typhimurium group 4 h after treatment in comparison with the animals receiving only S. typhimurium antigens alone by 1.9, 4.4, 1.5, and 6 times, respectively, i.e. to normal level or below it, while the concentration of IL-10 increased by almost 2 times, which probably reflected anti-inflammatory properties of BMP-2. These data probably attest to competitive relations between osteogenesis and immune response at the level of MSC. PMID:25708327

  12. What Is Combined Deficiency of Vitamin K-Dependent Clotting Factors?

    MedlinePlus

    ... or exposure to certain medications. Treatment There are three treatments available for VKCFD. Vitamin K Prothrombin complex concentrates (PCC) Fresh frozen plasma (FFP) See Treatment Options . Content developed by the ...

  13. Concentrating Radioactivity

    ERIC Educational Resources Information Center

    Herrmann, Richard A.

    1974-01-01

    By concentrating radioactivity contained on luminous dials, a teacher can make a high reading source for classroom experiments on radiation. The preparation of the source and its uses are described. (DT)

  14. Data Concentrator

    NASA Technical Reports Server (NTRS)

    Willett, Mike

    2015-01-01

    Orbital Research, Inc., developed, built, and tested three high-temperature components for use in the design of a data concentrator module in distributed turbine engine control. The concentrator receives analog and digital signals related to turbine engine control and communicates with a full authority digital engine control (FADEC) or high-level command processor. This data concentrator follows the Distributed Engine Controls Working Group (DECWG) roadmap for turbine engine distributed controls communication development that operates at temperatures at least up to 225 C. In Phase I, Orbital Research developed detailed specifications for each component needed for the system and defined the total system specifications. This entailed a combination of system design, compiling existing component specifications, laboratory testing, and simulation. The results showed the feasibility of the data concentrator. Phase II of this project focused on three key objectives. The first objective was to update the data concentrator design modifications from DECWG and prime contractors. Secondly, the project defined requirements for the three new high-temperature, application-specific integrated circuits (ASICs): one-time programmable (OTP), transient voltage suppression (TVS), and 3.3V. Finally, the project validated each design by testing over temperature and under load.

  15. Plutonium in Concentrated Solutions

    SciTech Connect

    Clark, Sue B.; Delegard, Calvin H.

    2002-08-01

    Complex, high ionic strength media are used throughout the plutonium cycle, from its processing and purification in nitric acid, to waste storage and processing in alkaline solutions of concentrated electrolytes, to geologic disposal in brines. Plutonium oxidation/reduction, stability, radiolysis, solution and solid phase chemistry have been studied in such systems. In some cases, predictive models for describing Pu chemistry under such non-ideal conditions have been developed, which are usually based on empirical databases describing specific ion interactions. In Chapter 11, Non-Ideal Systems, studies on the behavior of Pu in various complex media and available model descriptions are reviewed.

  16. Solar concentrator

    SciTech Connect

    Smyth, J.S.

    1982-06-08

    A solar concentrator having an open framework formed as a geodesic dome. A rotatable support axle extends substantially diametrically across the dome and has the opposite ends thereof supported on the framework. The support axle defines a first rotational axis which is oriented to extend substantially parallel with the earth's north-south axis. A support post is hingedly mounted on the support shaft substantially at the midpoint thereof for permitting angular displacement of the support post relative to the support shaft about a second rotational axis which is perpendicular to the first axis. A dishshaped reflector assembly is positioned within the interior of the framework and fixedly secured to the support post. First and second drives effect angular displacement of the reflector assembly about the first and second axes, respectively, to permit tracking of the solar position.

  17. Role of magmatic and fluid concentrating in formation of platinum mineralization in the Lower Zone and Platreef as follows from composition of phlogopite, cumulus silicates, and sulfide melt, the northern limb of Bushveld Complex

    NASA Astrophysics Data System (ADS)

    Yudovskaya, M. A.; Kinnaird, J. A.; Udachina, L. V.; Distler, V. V.; Kuz'min, D. V.

    2014-11-01

    As follows from the results of new geological exploration, the thick sequence of primitive cumulates of the Lower Zone underlies Platreef in separate magmatic depressions of the northern limb of the Bushveld Complex. In the Turfspruit area, the Lower Zone is separated from the overlying Platreef by an interval of contact metasedimentary rocks with sills of fine-grained norite and plagioclase orthopyroxenite of the Marginal Zone. The magmatic stratigraphy of Platreef in Turfspruit and its western plunge, where it is slightly contaminated with sedimentary rocks, is close to the section of Critical Zone in the Bushveld. The Lower Zone and Platreef contain sulfide mineralization enriched in PGE in particular units-reefs-throughout the section. The main reef can be correlated with the Merensky Reef. The objective of this study was to estimate the relationships between fluid and magmatic PGE concentrating in the reefs localized in the upper part of Platreef near its unconformable contact with the Main Zone. It is shown that Ni partitioning between cumulus olivine and orthopyroxene, on the one hand, and coexisting sulfide liquid, on the other, indicates their equilibrium crystallization in the Lower Zone and Platreef at close redox conditions. The composition of sulfide liquid was recalculated as sulfide tenor on the basis of bulk Ni, Cu, and S concentrations in rock. In contrast, Ni partitioning between phlogopite and sulfide melt does not provide evidence in favor of their equilibrium crystallization, although Mg # of phlogopite from the intercumulus assemblage is correlated with Mg # of cumulus mineral throughout the section. The results of phlogopite microprobing throughout the section show that the highest F and Cl contents are characteristic of highly evolved rocks, including both the PGE-bearing plagioclase pyroxenite from reefs and barren norite from the Marginal Zone. We have arrived at the conclusion that enrichment in volatile components is the attendant rather

  18. Amorphic complexity

    NASA Astrophysics Data System (ADS)

    Fuhrmann, G.; Gröger, M.; Jäger, T.

    2016-02-01

    We introduce amorphic complexity as a new topological invariant that measures the complexity of dynamical systems in the regime of zero entropy. Its main purpose is to detect the very onset of disorder in the asymptotic behaviour. For instance, it gives positive value to Denjoy examples on the circle and Sturmian subshifts, while being zero for all isometries and Morse-Smale systems. After discussing basic properties and examples, we show that amorphic complexity and the underlying asymptotic separation numbers can be used to distinguish almost automorphic minimal systems from equicontinuous ones. For symbolic systems, amorphic complexity equals the box dimension of the associated Besicovitch space. In this context, we concentrate on regular Toeplitz flows and give a detailed description of the relation to the scaling behaviour of the densities of the p-skeletons. Finally, we take a look at strange non-chaotic attractors appearing in so-called pinched skew product systems. Continuous-time systems, more general group actions and the application to cut and project quasicrystals will be treated in subsequent work.

  19. Endothelial Nitric Oxide Synthase T-786C Mutation, Prothrombin Gene Mutation (G-20210-A) and Protein S Deficiency Could Lead to Myocardial Infarction in a Very Young Male Adult

    PubMed Central

    Klincheva, Milka; Vilarova, Elena Ambarkova; Angjusheva, Tanja; Milev, Ivan; Idoski, Enver; Mitrev, Zan

    2016-01-01

    INTRODUCTION: Myocardial infarction is a rare medical event in young people. The main reasons include congenital coronary abnormalities, coronary artery spasm, and coronary thrombosis due to hypercoagulable states (hereditary and acquired). AIM: We present a case of a young male adult with myocardial infarction caused by a combination of gene mutations and anticoagulation protein deficiency. CASE PRESENTATION: A 19 years old young man was admitted to our hospital complaining of chest pain during the last two weeks. The patient did not have any known cardiovascular risk factors, except a positive family anamnesis. Subacute inferior nonST segment myocardial infarction was diagnosed according to the patient’s history, electrocardiographic and laboratory findings. Coronary angiography revealed suboclusive thrombus in the proximal, medial and distal part of the right coronary artery (TIMI 2). Percutaneous coronary intervention was performed. Anticoagulant and antiagregant therapy (heparin, acetilsalicilic acid and clopidogrel) according to protocol was started. The hospital stay was uneventful. Homozygous endothelial nitric oxid synthase (eNOS) T-786-C mutation, heterozygote prothrombin gene mutation (G-20210-A), and protein S deficiency were verified from the thrombophilia testing. Other trombophilic tests were normal. Three months after discharge from hospital another coronary angiography was performed. It revealed normal coronary arteries. Four years after the attack, the patient is free of symptoms and another cardiovascular event. CONCLUSION: Combination of genetic mutations and anticoagulation protein deficiency could be a reasonable cause for myocardial infarction in a very young male adult without any other cardiovascular risk factors. PMID:27275349

  20. Clinical utility of simultaneous measurement of alpha-fetoprotein and des-γ-carboxy prothrombin for diagnosis of patients with hepatocellular carcinoma in China: A multi-center case-controlled study of 1,153 subjects.

    PubMed

    Song, Peipei; Feng, Xiaobin; Inagaki, Yoshinori; Song, Tianqiang; Zhang, Keming; Wang, Zhigang; Zheng, Shuguo; Ma, Kuansheng; Li, Qiang; Kong, Dalu; Wu, Qiang; Zhang, Ti; Zhao, Xin; Hasegawa, Kiyoshi; Sugawara, Yasuhiko; Kokudo, Norihiro; Tang, Wei

    2014-10-01

    This study aimed to investigate the clinical utility of simultaneous measurement of alphafetoprotein (AFP) and des-γ-carboxy prothrombin (DCP) for hepatocellular carcinoma (HCC) diagnosis in Chinese patients predominantly caused by hepatitis B virus infection by a multi-center case-controlled study. Subjects were 1,153 individuals from three major hospitals in China, including 550 cases in HCC group, 164 in Malignant disease group, 182 in Benign disease group, 85 in Chronic liver disease group, and 173 in Normal group. Serum levels of AFP and DCP were measured and clinicopathological features were determined for all subjects. Results showed that the levels of DCP and AFP were significantly higher in HCC group (550 patients, 74.18% with HBV infection) than that in other four groups (P < 0.001). Receiver operating curves (ROC) indicated the optimal cut-off value was 86 mAU/mL for DCP with a sensitivity of 71.50% and specificity of 86.30%, and 21 ng/mL for AFP with a sensitivity of 68.00% and specificity of 93.20%. The area under ROC curve was 0.846 for DCP, 0.832 for AFP, and 0.890 for the combination of DCP and AFP. The combination of DCP and AFP resulted in a higher Youden index and a sensitivity of approximately 90%, even for small tumors. The simultaneous measurement of AFP and DCP could achieve a better sensitivity in diagnosing Chinese HCC patients, even for small tumors. PMID:25382443

  1. Two giant stellar complexes

    NASA Astrophysics Data System (ADS)

    Efremov, Yu. N.; Efremov, E. Yu.

    Common star complexes are huge (0.3-1 kpc in diameter) groups of relatively young stars, associations and clusters. The complexes usually form regular chains along spiral arms of grand design galaxies, being evidently formed and supported by magneto- gravitational instability developing along an arm. Special attention is given to a few large complexes which have signatures of gravitational boundness, such as round shape and high central density. Concentrations of stars and clusters in such a complex in M51 galaxy were found in this paper; we concluded it is possible to suggest that the complex is gravitationally bound. It is also stressed that some properties of the giant complex in NGC 6946 (such as its semicircular and sharp Western edge) are still enigmatic.

  2. Fibrinogen Substrate Recognition by Staphylocoagulase·(Pro)thrombin Complexes*

    PubMed Central

    Panizzi, Peter; Friedrich, Rainer; Fuentes-Prior, Pablo; Richter, Klaus; Bock, Paul E.; Bode, Wolfram

    2008-01-01

    Thrombin generation and fibrinogen (Fbg) clotting are the ultimate proteolytic reactions in the blood coagulation pathway. Staphylocoagulase (SC), a protein secreted by the human pathogen Staphylococcus aureus, activates prothrombin (ProT) without proteolysis. The SC·(pro)thrombin complex recognizes Fbg as a specific substrate, converting it directly into fibrin. The crystal structure of a fully active SC fragment containing residues 1–325 (SC-(1–325)) bound to human prethrombin 2 showed previously that SC inserts its Ile1-Val2 N terminus into the Ile16 pocket of prethrombin 2, inducing a functional active site in the cognate zymogen conformationally. Exosite I of α-thrombin, the Fbg recognition site, and proexosite I on ProT are blocked by domain 2 of SC-(1–325). In the present studies, active site-labeled fluorescent ProT analogs were used to quantitate Fbg binding to the SC-(1–325)·ProT complex. Fbg binding and cleavage are mediated by expression of a new Fbg-binding exosite on the SC-(1–325)·ProT complex, resulting in formation of an (SC-(1–325)·ProT)2·Fbg pentameric complex with a dissociation constant of 8–34 nM. In both crystal structures, the SC-(1–325)·(pre)thrombin complexes form dimers, with both pro-teinases/zymogens facing each other over a large U-shaped cleft, through which the Fbg substrate could thread. On this basis, a molecular model of the pentameric (SC-(1–325)·thrombin)2·Fbg encounter complex was generated, which explains the coagulant properties and efficient Fbg conversion. The results provide new insight into the mechanism that mediates high affinity Fbg binding and cleavage as a substrate of SC·(pro)thrombin complexes, a process that is central to the molecular pathology of S. aureus endocarditis. PMID:16230339

  3. Risk of venous thromboembolism associated with single and combined effects of Factor V Leiden, Prothrombin 20210A and Methylenetethraydrofolate reductase C677T: a meta-analysis involving over 11,000 cases and 21,000 controls

    PubMed Central

    Simone, B; De Stefano, V; Leoncini, E; Zacho, J; Martinelli, I; Emmerich, J; Rossi, E; Folsom, AR; Almawi, WY; Scarabin, PY; den Heijer, M; Cushman, M; Penco, S; Vaya, A; Angchaisuksiri, P; Okumus, G; Gemmati, D; Cima, S; Akar, N; Oguzulgen, KI; Ducros, V; Lichy, C; Fernandez-Miranda, C; Szczeklik, A; Nieto, JA; Torres, JD; Le Cam-Duchez, V; Ivanov, P; Cantu, C; Shmeleva, VM; Stegnar, M; Ogunyemi, D; Eid, SS; Nicolotti, N; De Feo, E; Ricciardi, W; Boccia, S

    2014-01-01

    BACKGROUND Genetic and environmental factors interact in determining the risk of venous thromboembolism (VTE). The risk associated with the polymorphic variants G1691A of factor V (Factor V Leiden,FVL), G20210A of prothrombin (PT20210A) and C677T of methylentetrahydrofolate reductase (C677T MTHFR) genes has been investigated in many studies. METHODS We performed a pooled analysis of case-control and cohort studies investigating in adults the association between each variant and VTE, published on Pubmed, Embase or Google through January 2010. Authors of eligible papers, were invited to provide all available individual data for the pooling. The Odds Ratio (OR) for first VTE associated with each variant, individually and combined with the others, were calculated with a random effect model, in heterozygotes and homozygotes (dominant model for FVL and PT20210A; recessive for C677T MTHFR). RESULTS We analysed 31 databases, including 11,239 cases and 21,521 controls. No significant association with VTE was found for homozygous C677T MTHFR (OR: 1.38; 95% confidence intervals [CI]: 0.98–1.93), whereas the risk was increased in carriers of either heterozygous FVL or PT20210 (OR=4.22; 95% CI: 3.35–5.32; and OR=2.79;95% CI: 2.25–3.46, respectively), in double hterozygotes (OR=3.42; 95%CI 1.64-7.13), and in homozygous FVL or PT20210A (OR=11.45; 95%CI: 6.79-19.29; and OR: 2.79; 95%CI: 2.25 – 3.46, respectively). The stratified analyses showed a stronger effect of FVL on individuals ≤45 years (p-value for interaction = 0.036) and of PT20210A in women using oral contraceptives (p-value for interaction = 0.045). CONCLUSIONS In this large pooled analysis, inclusive of large studies like MEGA, no effect was found for C677T MTHFR on VTE; FVL and PT20210A were confirmed to be moderate risk factors. Notably, double carriers of the two genetic variants produced an impact on VTE risk significantly increased but weaker than previously thought. PMID:23900608

  4. Copresence of tet(K) and tet(M) in Livestock-Associated Methicillin-Resistant Staphylococcus aureus Clonal Complex 398 Is Associated with Increased Fitness during Exposure to Sublethal Concentrations of Tetracycline

    PubMed Central

    Clasen, Julie; Hansen, Julie E.; Paulander, Wilhelm; Petersen, Andreas; Larsen, Anders R.; Frees, Dorte

    2016-01-01

    The tetracycline resistance gene tet(K) was shown to be integrated within the predominant staphylococcal cassette chromosome mec (SCCmec) element of Danish livestock-associated methicillin-resistant Staphylococcus aureus CC398 (LA-MRSA CC398). These LA-MRSA CC398 isolates already possessed tet(M), but the acquisition of tet(K) significantly improved their fitness at sublethal concentrations of tetracycline. Because tet(K) is genetically linked to SCCmec, the use of tetracycline in food animals may have contributed to the successful spread of LA-MRSA CC398. PMID:27161637

  5. Copresence of tet(K) and tet(M) in Livestock-Associated Methicillin-Resistant Staphylococcus aureus Clonal Complex 398 Is Associated with Increased Fitness during Exposure to Sublethal Concentrations of Tetracycline.

    PubMed

    Larsen, Jesper; Clasen, Julie; Hansen, Julie E; Paulander, Wilhelm; Petersen, Andreas; Larsen, Anders R; Frees, Dorte

    2016-07-01

    The tetracycline resistance gene tet(K) was shown to be integrated within the predominant staphylococcal cassette chromosome mec (SCCmec) element of Danish livestock-associated methicillin-resistant Staphylococcus aureus CC398 (LA-MRSA CC398). These LA-MRSA CC398 isolates already possessed tet(M), but the acquisition of tet(K) significantly improved their fitness at sublethal concentrations of tetracycline. Because tet(K) is genetically linked to SCCmec, the use of tetracycline in food animals may have contributed to the successful spread of LA-MRSA CC398. PMID:27161637

  6. Models for association of metal ions with heterogeneous environmental sorbents. 1. Complexation of Co(II) by leonardite humic acid as a function of pH and NaClO{sub 4} concentration

    SciTech Connect

    Westall, J.C.; Jones, J.D.; Turner, G.D. |; Zachara, J.M.

    1995-04-01

    A discrete log K spectrum model has been developed to represent the binding of protons and Co(II) to leonardite humic acid (LHA) over a wide variation of solution composition: pH 4.5-9.5, [NaClO{sub 4}] 0.01-0.1 M, T{sub Co} 200 nM-500 $mu@M. The model is internally self-consistent over the range indicated without an explicit electrostatic term. The LHA was represented by four acid sites (HL{sub i} = H{sup +} + L{sub i}{sup -}) with a fixed pK{sub a} spectrum: pK{sub a} = 4, 6, 8, and 10. From the acid-base titration data, total concentrations of these sites and Na{sup +} binding constants (L{sub i}{sup -} + Na{sup +} = NaL{sub i}) were obtained. From Co{sup 21} binding as a function of pH, constants for the reaction L{sub i}{sup -} + Co{sup 21} = CoL{sub i}{sup +} were obtained. Total concentrations of sites and binding constants were similar to those expected from other studies. This discrete log K approach has been selected as the easiest way to parameterize multidimensional data (i.e., data with variations in many solution chemistry parameters) for subsequent application in transport models. 37 refs., 3 figs., 6 tabs.

  7. Cosmic Complexity

    NASA Technical Reports Server (NTRS)

    Mather, John C.

    2012-01-01

    neutrons, liberating a little energy and creating complexity. Then, the expanding universe cooled some more, and neutrons and protons, no longer kept apart by immense temperatures, found themselves unstable and formed helium nuclei. Then, a little more cooling, and atomic nuclei and electrons were no longer kept apart, and the universe became transparent. Then a little more cooling, and the next instability began: gravitation pulled matter together across cosmic distances to form stars and galaxies. This instability is described as a "negative heat capadty" in which extracting energy from a gravitating system makes it hotter -- clearly the 2nd law of thermodynamics does not apply here! (This is the physicist's part of the answer to e e cummings' question: what is the wonder that's keeping the stars apart?) Then, the next instability is that hydrogen and helium nuclei can fuse together to release energy and make stars burn for billions of years. And then at the end of the fuel source, stars become unstable and explode and liberate the chemical elements back into space. And because of that, on planets like Earth, sustained energy flows support the development of additional instabilities and all kinds of complex patterns. Gravitational instability pulls the densest materials into the core of the Earth, leaving a thin skin of water and air, and makes the interior churn incessantly as heat flows outwards. And the heat from the sun, received mostly near the equator and flowing towards the poles, supports the complex atmospheric and oceanic circulations. And because or that, the physical Earth is full of natural chemical laboratories, concentrating elements here, mixing them there, raising and lowering temperatures, ceaselessly experimenting with uncountable events where new instabilities can arise. At least one of them was the new experiment called life. Now that we know that there are at least as many planets as there are stars, it is hard to imagine that nature's ceasess

  8. Cosmic Complexity

    NASA Technical Reports Server (NTRS)

    Mather, John C.

    2012-01-01

    neutrons, liberating a little energy and creating complexity. Then, the expanding universe cooled some more, and neutrons and protons, no longer kept apart by immense temperatures, found themselves unstable and formed helium nuclei. Then, a little more cooling, and atomic nuclei and electrons were no longer kept apart, and the universe became transparent. Then a little more cooling, and the next instability began: gravitation pulled matter together across cosmic distances to form stars and galaxies. This instability is described as a "negative heat capadty" in which extracting energy from a gravitating system makes it hotter -- clearly the 2nd law of thermodynamics does not apply here! (This is the physicist's part of the answer to e e cummings' question: what is the wonder that's keeping the stars apart?) Then, the next instability is that hydrogen and helium nuclei can fuse together to release energy and make stars burn for billions of years. And then at the end of the fuel source, stars become unstable and explode and liberate the chemical elements back into space. And because of that, on planets like Earth, sustained energy flows support the development of additional instabilities and all kinds of complex patterns. Gravitational instability pulls the densest materials into the core of the Earth, leaving a thin skin of water and air, and makes the interior churn incessantly as heat flows outwards. And the heat from the sun, received mostly near the equator and flowing towards the poles, supports the complex atmospheric and oceanic circulations. And because or that, the physical Earth is full of natural chemical laboratories, concentrating elements here, mixing them there, raising and lowering temperatures, ceaselessly experimenting with uncountable events where new instabilities can arise. At least one of them was the new experiment called life. Now that we know that there are at least as many planets as there are stars, it is hard to imagine that nature's ceasess

  9. Complex equiangular tight frames

    NASA Astrophysics Data System (ADS)

    Tropp, Joel A.

    2005-08-01

    A complex equiangular tight frame (ETF) is a tight frame consisting of N unit vectors in Cd whose absolute inner products are identical. One may view complex ETFs as a natural geometric generalization of an orthonormal basis. Numerical evidence suggests that these objects do not arise for most pairs (d, N). The goal of this paper is to develop conditions on (d, N) under which complex ETFs can exist. In particular, this work concentrates on the class of harmonic ETFs, in which the components of the frame vectors are roots of unity. In this case, it is possible to leverage field theory to obtain stringent restrictions on the possible values for (d, N).

  10. REM-containing silicate concentrates

    NASA Astrophysics Data System (ADS)

    Pavlov, V. F.; Shabanova, O. V.; Pavlov, I. V.; Pavlov, M. V.; Shabanov, A. V.

    2016-01-01

    A new method of advanced complex processing of ores containing rare-earth elements (REE) is proposed to obtain porous X-ray amorphous aluminosilicate material with a stable chemical composition which concentrates oxides of rare-earth metals (REM). The ferromanganese oxide ores of Chuktukon deposit (Krasnoyarsk Region, RF) were used for the experiment. The obtained aluminosilicate material is appropriate for treatment with 5 - 15% solutions of mineral acids to leach REM.

  11. Complexity Survey.

    ERIC Educational Resources Information Center

    Gordon, Sandra L.; Anderson, Beth C.

    To determine whether consensus existed among teachers about the complexity of common classroom materials, a survey was administered to 66 pre-service and in-service kindergarten and prekindergarten teachers. Participants were asked to rate 14 common classroom materials as simple, complex, or super-complex. Simple materials have one obvious part,…

  12. Comparison of serum procollagen III peptide concentrations and PGA index for assessment of hepatic fibrosis.

    PubMed

    Teare, J P; Sherman, D; Greenfield, S M; Simpson, J; Bray, G; Catterall, A P; Murray-Lyon, I M; Peters, T J; Williams, R; Thompson, R P

    1993-10-01

    In early hepatic fibrosis, increased amounts of type III collagen are deposited. Persistently high serum concentrations of aminoterminal type III procollagen propeptide (PIIIP) correlate with the activity of the fibrogenic process. Another index for the detection of fibrosis, the PGA index, combines the prothrombin time, gamma-glutamyl transpeptidase activity, and serum apolipoprotein A1 concentration (the latter falls with progressive fibrosis). We compared PIIIP measurements and PGA index in patients with various histological forms of alcoholic liver disease (104), primary biliary cirrhosis (38), and chronic B virus hepatitis (27), and in healthy age-matched controls (30). The ability of each test to identify correctly patients with fibrosis or cirrhosis was assessed with receiver operating curves. The PGA index was much higher in all groups of patients with alcoholic liver disease than in controls (p < 0.0001). PIIIP concentrations were also substantially higher than in controls (p < 0.05 for fatty liver, p < 0.0001 for all other groups), especially in the group with alcoholic hepatitis and cirrhosis. For the detection of cirrhosis the PGA was 91% sensitive and 81% specific and the PIIIP concentration was 94% sensitive and 81% specific. The two tests combined had 85% sensitivity, but 93% specificity. Among patients with primary biliary cirrhosis, both PGA index and PIIIP concentration correlated well with the severity of the disease, determined by the Mayo score (r = 0.72 and 0.66 respectively). The combined tests were 96% sensitive for the detection of fibrosis. All patients with chronic B virus hepatitis had raised PGA and PIIIP values in comparison with controls (p < 0.0001) but there were no differences between subgroups. Substantially raised PIIIP concentrations thus identify the subgroup of alcoholic patients with both hepatitis and cirrhosis. The combination of PGA index and PIIIP concentration may be useful for targeting treatment with antifibrotic drugs

  13. Communication complexity and information complexity

    NASA Astrophysics Data System (ADS)

    Pankratov, Denis

    Information complexity enables the use of information-theoretic tools in communication complexity theory. Prior to the results presented in this thesis, information complexity was mainly used for proving lower bounds and direct-sum theorems in the setting of communication complexity. We present three results that demonstrate new connections between information complexity and communication complexity. In the first contribution we thoroughly study the information complexity of the smallest nontrivial two-party function: the AND function. While computing the communication complexity of AND is trivial, computing its exact information complexity presents a major technical challenge. In overcoming this challenge, we reveal that information complexity gives rise to rich geometrical structures. Our analysis of information complexity relies on new analytic techniques and new characterizations of communication protocols. We also uncover a connection of information complexity to the theory of elliptic partial differential equations. Once we compute the exact information complexity of AND, we can compute exact communication complexity of several related functions on n-bit inputs with some additional technical work. Previous combinatorial and algebraic techniques could only prove bounds of the form theta( n). Interestingly, this level of precision is typical in the area of information theory, so our result demonstrates that this meta-property of precise bounds carries over to information complexity and in certain cases even to communication complexity. Our result does not only strengthen the lower bound on communication complexity of disjointness by making it more exact, but it also shows that information complexity provides the exact upper bound on communication complexity. In fact, this result is more general and applies to a whole class of communication problems. In the second contribution, we use self-reduction methods to prove strong lower bounds on the information

  14. Photovoltaic concentrator module technology

    NASA Astrophysics Data System (ADS)

    Richards, Elizabeth H.; Chamberlin, Jay L.; Boes, Eldon C.

    Significant developments in the development of photovoltaic (PV) concentrator technology are described. Concentrator cell research, advances in PV concentrator cell technology, and PV concentrator module development are described. Reliability issues currently of concern, including the applicability of wet insulation resistance tests to concentrator modules, correlation of accelerated thermal cycling tests with life expectancy in the field, and the importance of quality assurance during manufacture, are discussed. Two PV concentrator power systems installed in 1989 are discussed. A PV concentrator initiative program established by the DOE is given, and the results of the latest cost study are presented.

  15. Acquired hemophilia A in a patient with systemic lupus erythematosus.

    PubMed

    Ishikawa, T; Tsukamoto, N; Suto, M; Uchiumi, H; Mitsuhashi, H; Yokohama, A; Maesawa, A; Nojima, Y; Naruse, T

    2001-06-01

    A patient with systemic lupus erythematosus (SLE) developed acquired hemophilia A. The patient, a 24-year-old Japanese woman, was referred to our hospital because of uncontrollable bleeding following a tooth extraction. Laboratory examination revealed prolonged APTT (116 seconds), reduced factor VIII activity (2.8 %) and the presence of factor VIII inhibitor at a titer of 46.5 Bethesda units/ml. Transfusion of prothrombin complex concentrate and activated prothrombin complex concentrate followed by administration of prednisolone and cyclophosphamide successfully arrested bleeding and reduced the factor VIII inhibitor level. Acquired hemophilia A is a rare but lethal condition. Rapid diagnosis and introduction of adequate therapies are critical. PMID:11446683

  16. Complex derivatives

    NASA Astrophysics Data System (ADS)

    Battiston, Stefano; Caldarelli, Guido; Georg, Co-Pierre; May, Robert; Stiglitz, Joseph

    2013-03-01

    The intrinsic complexity of the financial derivatives market has emerged as both an incentive to engage in it, and a key source of its inherent instability. Regulators now faced with the challenge of taming this beast may find inspiration in the budding science of complex systems.

  17. Designing Complexity

    ERIC Educational Resources Information Center

    Glanville, Ranulph

    2007-01-01

    This article considers the nature of complexity and design, as well as relationships between the two, and suggests that design may have much potential as an approach to improving human performance in situations seen as complex. It is developed against two backgrounds. The first is a world view that derives from second order cybernetics and radical…

  18. Photovoltaic concentrator initiative: Concentrator cell development

    SciTech Connect

    Wohlgemuth, J.H.; Narayanan, S.

    1993-05-01

    This project involves the development of a large-area, low-cost, high-efficiency concentrator solar cell for use in the Entech 22-sun linear-focus Fresnel lens concentrator system. The buried contact solar cell developed at the University of New South Wales was selected for this project. Both Entech and the University of New South Wales are subcontractors. This annual report presents the program efforts from November 1990 through December 1991, including the design of the cell, development of a baseline cell process, and presentation of the results of preliminary cell processing. Important results include a cell designed for operation in a real concentrator system and substitution of mechanical grooving for the previously utilized laser scribing.

  19. Oxygen-Concentrating Cell

    NASA Technical Reports Server (NTRS)

    Buehler, K.

    1986-01-01

    High-purity oxygen produced from breathing air or from propellantgrade oxygen in oxygen-concentrating cell. Operating economics of concentrator attractive: Energy consumption about 4 Wh per liter of oxygen, slightly lower than conventional electrochemical oxygen extractors.

  20. Urine concentration test

    MedlinePlus

    A urine concentration test measures the ability of the kidneys to conserve or excrete water. ... Increased urine concentration may be due to different conditions, such as: Heart failure Loss of body fluids (dehydration) from diarrhea or ...

  1. Effects of soluble organic complexants and their degradation products on the removal of selected radionuclides from high-level waste. Part 3, Distributions of Sr, Cs, Tc, Pu, and Am onto 33 absorbers from four variations of a 3:1 dilution of Hanford complexant concentrate (CC) simulant: Part 4, The effects of varying dilution ratios on the distributions of Sr, Cs, Tc, Pu, and Am onto 12 absorbers

    SciTech Connect

    Marsh, S.F.; Svitra, Z.V.; Bowen, S.M.

    1995-09-01

    Many of the radioactive waste storage tanks at USDOE facilities contain organic compounds that have been degraded by radiolysis and chemical reactions during decades of storage. Objective of this study was to measure effects of soluble organic complexants and their degradation products on sorption of Sr, Cs, Tc, Pu and Am onto 33 absorbers that in the absence of these organic compounds offer high sorption of these elements. The elements were in a generic simulant for Hanford complexant concentrate supernate that initially contained six organic complexants: EDTA, HEDTA, NTA, citrate, gluconate, and iminodiacetate. This simulant was tested as prepared and after gamma-irradiation to approximately 34 Mrads. Two other variations consisted of the unirradiated and irradiated simulants after treatment at 450C and 15,000 psi in a hydrothermal organic-destruction process. These experiments were conducted with a 3:1 water-to-simulant dilution of each of the four simulant variations. To determine effects of varying dilution ratios on the sorption of these five elements from the unirradiated and gamma-irradiated simulants that were not treated with the hydrothermal process, we measured their distribution from a 1:1 dilution, using 1 M NaOH as the diluent, onto the 12 best-performing absorbers. We then measured the sorption of these five elements from solutions having diluent-simulant ratios of 0, 0.5, 2.0, and 3.0 onto the three absorbers that performed best for sorbing Sr, Pu and Am from the 1:1 dilution. For each of 900 element/absorber/solution combinations, we measured distribution coefficients (Kd values) twice for each period for dynamic contact periods of 30 min, 2 h, and 6 h to obtain information about absorber stability and sorption kinetics. The 5400 measured Kd values indicate that the sorption of Sr, Pu, and Am is significantly decreased by the organic complexants in these simulant solutions, whereas the sorption of Cs and Tc is much less affected.

  2. Carney Complex

    MedlinePlus

    ... Screening guidelines may change over time as new technologies are developed and more is learned about Carney complex. It is important to talk with your doctor about appropriate screening tests. Learn more about what to expect when having ...

  3. Recovery of fibrinogen concentrate after intraosseous application is equivalent to the intravenous route in a porcine model of hemodilution

    PubMed Central

    Schlimp, Christoph J.; Solomon, Cristina; Keibl, Claudia; Zipperle, Johannes; Nürnberger, Sylvia; Öhlinger, Wolfgang; Redl, Heinz; Schöchl, Herbert

    2014-01-01

    BACKGROUND Fibrinogen concentrate is increasingly considered as a hemostatic agent for trauma patients experiencing bleeding. Placing a venous access is sometimes challenging during severe hemorrhage. Intraosseous access may be considered instead. Studies of intraosseous infusion of coagulation factor concentrates are limited. We investigated in vivo recovery following intraosseous administration of fibrinogen concentrate and compared the results with intravenous administration. METHODS This study was performed on 12 pigs (mean [SD] body weight, 34.1 [2.8] kg). Following controlled blood loss (35 mL/kg) and fluid replacement with balanced crystalloid solution, intraosseous (n = 6) administration of fibrinogen concentrate (80 mg per kilogram of bodyweight) in the proximal tibia was compared with intravenous (n = 6) administration of the same dose (fibrinogen infusion time approximately 5 minutes in both groups). The following laboratory parameters were assessed: blood cell count, prothrombin time index, activated partial thromboplastin time, and plasma fibrinogen concentration (Clauss assay). Coagulation status was also assessed by thromboelastometry. RESULTS All tested laboratory parameters were comparable between the intraosseous and intravenous groups at baseline, hemodilution, and 30 minutes after fibrinogen concentrate administration. In vivo recovery of fibrinogen was also similar in the two groups (89% [23%] and 91% [22%], respectively). There were no significant between-group differences in any of the thromboelastometric parameters. Histologic examination indicated no adverse effects on the tissue surrounding the intraosseous administration site. CONCLUSION This study suggests that intraosseous administration of fibrinogen concentrate results in a recovery of fibrinogen similar to that of intravenous administration. The intraosseous route of fibrinogen concentrate could be a valuable alternative in situations where intravenous access is not feasible or would

  4. Experimental investigation of outdoor and indoor mean concentrations and concentration fluctuations of pollutants

    NASA Astrophysics Data System (ADS)

    Santos, J. M.; Mavroidis, I.; Reis, N. C.; Pagel, E. C.

    2011-11-01

    Tracer gas was released upwind of a two-compartment complex shaped building under unstable atmospheric conditions. The mean wind direction was normal to or at 45° to the long face of the building. The general patterns of concentration distribution on the building external walls and inside the building were analysed and the influence of natural and mechanical ventilation on indoor concentration distributions was discussed. Mean concentration levels, as well as the concentration fluctuation intensity, were higher on the windward walls of the building, although concentration levels varied along each wall. Concentration fluctuations measured inside the building were lower than those measured outside. Inside the two compartments of the building, the time series of concentrations had a similar general behaviour; however, gas concentrations took approximately 1.5 times longer to reach the mean maximum concentration value at the downwind compartment 02 while they also decreased more rapidly in the upwind compartment 01 after the source was turned off. The highest indoor concentration and concentration fluctuation values were observed at the detectors located close to the windward walls, especially when the building windows were open. Experiments with and without natural ventilation suggested that infiltration and exfiltration of contaminants is much faster when the building windows are open, resulting to higher indoor concentration levels. Furthermore, mechanical ventilation tends to homogenize concentrations and suppress concentration fluctuations, leading to lower maximum concentration values.

  5. Complex networks: Patterns of complexity

    NASA Astrophysics Data System (ADS)

    Pastor-Satorras, Romualdo; Vespignani, Alessandro

    2010-07-01

    The Turing mechanism provides a paradigm for the spontaneous generation of patterns in reaction-diffusion systems. A framework that describes Turing-pattern formation in the context of complex networks should provide a new basis for studying the phenomenon.

  6. Automated solvent concentrator

    NASA Technical Reports Server (NTRS)

    Griffith, J. S.; Stuart, J. L.

    1976-01-01

    Designed for automated drug identification system (AUDRI), device increases concentration by 100. Sample is first filtered, removing particulate contaminants and reducing water content of sample. Sample is extracted from filtered residue by specific solvent. Concentrator provides input material to analysis subsystem.

  7. Photovoltaic concentrator research status

    SciTech Connect

    Arvizu, D.E.

    1985-01-01

    This paper describes the most important developments in concentrator research and development since the fifth E.C. Photovoltaic Energy Conference in October 1983. Within the Sandia managed Photovoltaic Concentrator Research Project several record cell efficiencies have been reported. Applied Solar Energy Corporation has fabricated a concentrator silicon cell with 20.9% peak efficiency, at 90X concentration. Varian Associates has demonstrated a 26.0% efficient GaAs cell at 700X concentration. Hughes Research Labs together with Applied Solar Energy Corporation and Sandia has demonstrated a 24.7% efficient, at 70X concentration, mechanically-stacked multijunction device using GaAs on silicon. In addition, a record efficiency for silicon technology has been demonstrated with the Sandia developed 200X silicon module. The module has been measured to have 17% peak efficiency. This paper will review these accomplishments, other research progress, and current research directions in concentrator cells, modules, and arrays. A brief economic assessment is also presented which indicates the potential of concentrator technology.

  8. Extracting concentrated guided light.

    PubMed

    Ries, H; Segal, A; Karni, J

    1997-05-01

    The maximum concentration of radiation is proportional to the square of the refractive index of the medium in which it propagates. A medium with a high refractive index can also serve as a lightguide for concentrated radiation. However, if concentrated radiation is extracted from one medium, with a high refractive index, to another, whose index is lower (e.g., from fused silica into air), part of the radiation may be lost because of the total internal reflection at the interface. We present polygonal shapes suitable for efficient extraction of the concentrated radiation in a controllable way, without increasing the cross-section area (or diameter) of the lightguide. It is shown analytically and experimentally that the use of a secondary concentrator, followed by such a light extractor, both having a high refractive index, can provide considerably more power to a solar receiver with a specific aperture. PMID:18253285

  9. Uranium concentrations in asparagus

    SciTech Connect

    Tiller, B.L.; Poston, T.M.

    1992-05-01

    Concentrations of uranium were determined in asparagus collected from eight locations near and ten locations on the Hanford Site southcentral Washington State. Only one location (Sagemoor) had samples with elevated concentrations. The presence of elevated uranium in asparagus at Sagemoor may be explained by the elevated levels in irrigation water. These levels of uranium are comparable to levels previously reported upstream and downstream of the 300-FF-1 Operable Unit on the Hanford Site (0.0008 {mu}g/g), but were below the 0.020-{mu}g/g level reported for brush collected at Sagemoor in a 1982 study. Concentrations at all other onsite and offsite sample locations were considerably lower than concentrations reported immediately upstream and downstream of the 300-FF-1 Operable Unit. Using an earlier analysis of the uranium concentrations in asparagus collected from the Hanford Site constitutes a very small fraction of the US Department of Energy effective dose equivalent limit of 100 mrem.

  10. Researching Complexity.

    ERIC Educational Resources Information Center

    Sumara, Dennis J.

    2000-01-01

    Discusses what Complexity Theory (presented as a rubric that collects theoretical understandings from a number of domains such as ecology, biology, neurology, and education) suggests about mind, selfhood, intelligence, and practices of reading, and the import of these reconceptualizations to reader-response researchers. Concludes that developing…

  11. Complex Clouds

    Atmospheric Science Data Center

    2013-04-16

    ...     View Larger Image The complex structure and beauty of polar clouds are highlighted by these images acquired ... Multi-angle Imaging SpectroRadiometer observes the daylit Earth continuously from pole to pole, and every 9 days views the entire globe ...

  12. Complex interactions

    NASA Astrophysics Data System (ADS)

    de Régules, Sergio

    2016-04-01

    Complexity science – which describes phenomena such as collective and emergent behaviour – is the focus of a new centre where researchers are examining everything from the spread of influenza to what a healthy heartbeat looks like. Sergio de Régules reports.

  13. Concentrating photovoltaic solar panel

    SciTech Connect

    Cashion, Steven A; Bowser, Michael R; Farrelly, Mark B; Hines, Braden E; Holmes, Howard C; Johnson, Jr., Richard L; Russell, Richard J; Turk, Michael F

    2014-04-15

    The present invention relates to photovoltaic power systems, photovoltaic concentrator modules, and related methods. In particular, the present invention features concentrator modules having interior points of attachment for an articulating mechanism and/or an articulating mechanism that has a unique arrangement of chassis members so as to isolate bending, etc. from being transferred among the chassis members. The present invention also features adjustable solar panel mounting features and/or mounting features with two or more degrees of freedom. The present invention also features a mechanical fastener for secondary optics in a concentrator module.

  14. Concentration of Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F. (Inventor)

    2006-01-01

    Methods for concentrating hydrogen peroxide solutions have been described. The methods utilize a polymeric membrane separating a hydrogen peroxide solution from a sweep gas or permeate. The membrane is selective to the permeability of water over the permeability of hydrogen peroxide, thereby facilitating the concentration of the hydrogen peroxide solution through the transport of water through the membrane to the permeate. By utilizing methods in accordance with the invention, hydrogen peroxide solutions of up to 85% by volume or higher may be generated at a point of use without storing substantial quantities of the highly concentrated solutions and without requiring temperatures that would produce explosive mixtures of hydrogen peroxide vapors.

  15. Concentrator silicon cell research

    SciTech Connect

    Green, M.A.; Wenham, S.R.; Zhang, F.; Zhao, J.; Wang, A.

    1992-04-01

    This project continued the developments of high-efficiency silicon concentrator solar cells with the goal of achieving a cell efficiency in the 26 to 27 percent range at a concentration level of 150 suns of greater. The target efficiency was achieved with the new PERL (passivated emitter, rear locally diffused) cell structure, but only at low concentration levels around 20 suns. The PERL structure combines oxide passivation of both top and rear surfaces of the cells with small area contact to heavily doped regions on the top and rear surfaces. Efficiency in the 22 to 23 percent range was also demonstrated for large-area concentrator cells fabricated with the buried contact solar cell processing sequence, either when combined with prismatic covers or with other innovative approaches to reduce top contact shadowing. 19 refs.

  16. Cryogenic flux-concentrator

    NASA Technical Reports Server (NTRS)

    Bailey, B. M.; Brechna, H.; Hill, D. A.

    1969-01-01

    Flux concentrator has high primary to secondary coupling efficiency enabling it to produce high magnetic fields. The device provides versatility in pulse duration, magnetic field strengths and power sources.

  17. Water Sample Concentrator

    ScienceCinema

    Idaho National Laboratory

    2010-01-08

    Automated portable device that concentrates and packages a sample of suspected contaminated water for safe, efficient transport to a qualified analytical laboratory. This technology will help safeguard against pathogen contamination or chemical and biolog

  18. Water Sample Concentrator

    SciTech Connect

    Idaho National Laboratory

    2009-07-21

    Automated portable device that concentrates and packages a sample of suspected contaminated water for safe, efficient transport to a qualified analytical laboratory. This technology will help safeguard against pathogen contamination or chemical and biolog

  19. Concentration and content.

    PubMed

    Fuentes-Arderiu, Xavier

    2013-01-01

    One of the more frequent activities in health sciences is the measurement of biological quantities. Frequently, when reading biomedical books and journals some confusion on the metrological meaning of biological quantities related to the concepts 'concentration' and 'content' may be observed. Classically, a concentration is an amount of any type per volume of liquid or gas system, whereas content is an amount of any type per mass of liquid or gas or solid system. However the concepts 'concentration' and 'content' alone are still ambiguous because, depending on the type of amount of the component (analyte) per volume or mass of a system, there are different types of concentrations and contents. This article attempts to give a clarification of these concepts, mainly based on international recommendations about nomenclature and terminology of metrology, chemistry and clinical laboratory sciences. PMID:23894859

  20. Rheology of concentrated biomass

    NASA Astrophysics Data System (ADS)

    Samaniuk, J. R.; Wang, J.; Root, T. W.; Scott, C. T.; Klingenberg, D. J.

    2011-12-01

    Economic processing of lignocellulosic biomass requires handling the biomass at high solids concentration. This creates challenges because concentrated biomass behaves as a Bingham-like material with large yield stresses. Here we employ torque rheometry to measure the rheological properties of concentrated lignocellulosic biomass (corn stover). Yield stresses obtained using torque rheometry agree with those obtained using other rheometric methods, but torque rheometry can be used at much larger solids concentration (weight fractions of insoluble solids greater than 0.2). Yield stresses decrease with severity of hydrolysis, decrease when water-soluble polymers are added (for nonhydrolyzed biomass), and increase with particle length. Experimental results are qualitatively consistent with those obtained from particle-level simulations.

  1. Managing Complexity

    SciTech Connect

    Chassin, David P.; Posse, Christian; Malard, Joel M.

    2004-08-01

    Physical analogs have shown considerable promise for understanding the behavior of complex adaptive systems, including macroeconomics, biological systems, social networks, and electric power markets. Many of today’s most challenging technical and policy questions can be reduced to a distributed economic control problem. Indeed, economically-based control of large-scale systems is founded on the conjecture that the price-based regulation (e.g., auctions, markets) results in an optimal allocation of resources and emergent optimal system control. This paper explores the state of the art in the use physical analogs for understanding the behavior of some econophysical systems and to deriving stable and robust control strategies for them. In particular we review and discussion applications of some analytic methods based on the thermodynamic metaphor according to which the interplay between system entropy and conservation laws gives rise to intuitive and governing global properties of complex systems that cannot be otherwise understood.

  2. Advanced concentrator panels

    NASA Technical Reports Server (NTRS)

    Bell, D. M.; Bedard, R. J., Jr.

    1981-01-01

    The prototype fabrication of a lightweight, high-quality cellular glass substrate reflective panel for use in an advanced point-focusing solar concentrator was completed. The reflective panel is a gore shaped segment of an 11-m paraboloidal dish. The overall concentrator design and the design of the reflective panels are described. prototype-specific panel design modifications are discussed and the fabrication approach and procedure outlined.

  3. METHOD OF ISOTOPE CONCENTRATION

    DOEpatents

    Spevack, J.S.

    1957-04-01

    An isotope concentration process is described which consists of exchanging, at two or more different temperature stages, two isotopes of an element between substances that are physically separate from each other and each of which is capable of containing either of the isotopes, and withdrawing from a point between at least two of the temperatare stages one of the substances containing an increased concentration of the desired isotope.

  4. Joined concentric tubes

    SciTech Connect

    DeJonghe, Lutgard; Jacobson, Craig; Tucker, Michael; Visco, Steven

    2013-01-01

    Tubular objects having two or more concentric layers that have different properties are joined to one another during their manufacture primarily by compressive and friction forces generated by shrinkage during sintering and possibly mechanical interlocking. It is not necessary for the concentric tubes to display adhesive-, chemical- or sinter-bonding to each other in order to achieve a strong bond. This facilitates joining of dissimilar materials, such as ceramics and metals.

  5. Thermal regeneration of an electrochemical concentration cell

    DOEpatents

    Krumpelt, M.; Bates, J.K.

    1980-05-09

    A system and method are described for thermally regenerating an electrochemical concentration cell having first and second aluminum electrodes respectively positioned in contact with first and second electrolytes separated by an ion exchange member, the first and second electrolytes being composed of different concentrations of an ionic solvent and a salt, preferably an aluminum halide. The ionic solvent may be either organic or inorganic with a relatively low melting point, the ionic solvent and the salt form a complex wherein the free energy of formation of said complex is less than about -5 kcal/mole. A distillation column using solar heat or low grade industrial waste heat receives the first and second electrolytes and thermally decomposes the salt-solvent complex to provide feed material for the two half cells.

  6. Thermal regeneration of an electrochemical concentration cell

    DOEpatents

    Krumpelt, Michael; Bates, John K.

    1981-01-01

    A system and method for thermally regenerating an electrochemical concentration cell having first and second aluminum electrodes respectively positioned in contact with first and second electrolytes separated by an ion exchange member, the first and second electrolytes being composed of different concentrations of an ionic solvent and a salt, preferably an aluminum halide. The ionic solvent may be either organic or inorganic with a relatively low melting point, the ionic solvent and the salt form a complex wherein the free energy of formation of said complex is less than about -5 Kcal/mole. A distillation column using solar heat or low grade industrial waste heat receives the first and second electrolytes and thermally decomposes the salt-solvent complex to provide feed material for the two half cells.

  7. Concentration and purification of plutonium or thorium

    DOEpatents

    Hayden, John A.; Plock, Carl E.

    1976-01-01

    In this invention a first solution obtained from such as a plutonium/thorium purification process or the like, containing plutonium (Pu) and/or thorium (Th) in such as a low nitric acid (HNO.sub.3) concentration may have the Pu and/or Th separated and concentrated by passing an electrical current from a first solution having disposed therein an anode to a second solution having disposed therein a cathode and separated from the first solution by a cation permeable membrane, the Pu or Th cation permeating the cation membrane and forming an anionic complex within the second solution, and electrical current passage affecting the complex formed to permeate an anion membrane separating the second solution from an adjoining third solution containing disposed therein an anode, thereby effecting separation and concentration of the Pu and/or Th in the third solution.

  8. Complex Systems

    PubMed Central

    Goldberger, Ary L.

    2006-01-01

    Physiologic systems in health and disease display an extraordinary range of temporal behaviors and structural patterns that defy understanding based on linear constructs, reductionist strategies, and classical homeostasis. Application of concepts and computational tools derived from the contemporary study of complex systems, including nonlinear dynamics, fractals and “chaos theory,” is having an increasing impact on biology and medicine. This presentation provides a brief overview of an emerging area of biomedical research, including recent applications to cardiopulmonary medicine and chronic obstructive lung disease. PMID:16921107

  9. [Carney complex].

    PubMed

    Kacerovská, D; Michal, M; Síma, R; Grossmann, P; Kazakov, D V

    2011-10-01

    Carney complex is a clinically and genetically heterogeneous disease, with at least two genetic loci including the PRKAR1A gene located on chromosome 17 and the CNC2 locus mapped to chromosome 2. Clinically this syndrome is characterized by multiple myxomas occurring in different anatomic sites, mucocutaneous pigmentary lesions, and a variety of non-endocrine and endocrine tumors, often causing endocrine abnormalities, involving various organs. Knowledge of morphological findings in CNC patients with their typical locations is necessary to raise suspicion of this syndrome by pathologists. Confirmation of the diagnosis allows regular clinical check-ups and early treatment of these patients. PMID:22145222

  10. Solar concentrator protective system

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K. (Inventor)

    1984-01-01

    A mechanism that blocks concentrated sunlight from reaching a receiver, in the event of a tracking failure or loss of coolant is described. Sunlight is normally concentrated by a dish reflector onto the opening of a receiver. A faceplate surrounds the opening, and coolant carrying tubes, line the receiver. If the concentrated sunlight wanders so it begins to fall on the faceplate, then the sunlight will melt a portion of a fuse wire portion will break. The wire is attached to a flange on a shutter frame, and breaking of the fuse wire allows the frame to fall. Normally, the shutter frame supports shutter elements that are held open by cam followers that bear against cams.

  11. Photovoltaic solar concentrator

    DOEpatents

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2016-03-15

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  12. Photovoltaic solar concentrator

    DOEpatents

    Nielson, Gregory N.; Okandan, Murat; Resnick, Paul J.; Cruz-Campa, Jose Luis

    2012-12-11

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  13. Airborne agent concentration analysis

    DOEpatents

    Gelbard, Fred

    2004-02-03

    A method and system for inferring airborne contaminant concentrations in rooms without contaminant sensors, based on data collected by contaminant sensors in other rooms of a building, using known airflow interconnectivity data. The method solves a least squares problem that minimizes the difference between measured and predicted contaminant sensor concentrations with respect to an unknown contaminant release time. Solutions are constrained to providing non-negative initial contaminant concentrations in all rooms. The method can be used to identify a near-optimal distribution of sensors within the building, when then number of available sensors is less than the total number of rooms. This is achieved by having a system-sensor matrix that is non-singular, and by selecting that distribution which yields the lowest condition number of all the distributions considered. The method can predict one or more contaminant initial release points from the collected data.

  14. Photovoltaic concentrator research progress

    SciTech Connect

    Arvizu, D.E.

    1985-01-01

    This paper provides a review of progress in the DOE sponsored, Sandia managed Photovoltaic Concentrator Research Project. Research status, project goals and a discussion of concentrator economics is presented. Recent research accomplishments that will be discussed include 21% efficient baseline silicon cells by Applied Solar Energy Corporation and Sandia, 26% efficient GaAs cells by Varian Associates, and near 25% mechanically stacked multijunction GaAs/Si cells by Hughes Research, Applied Solar, and Sandia. In addition, improvements in breadboard module units (i.e. single lens/cell combination) such as a 19% GaAs unit by Varian and a near 17% silicon unit by ENTECH will be reviewed. This paper concludes that the photovoltaic concentrator option is making excellent progress toward competitive cost-effectiveness and provides a strong photovoltaic alternative.

  15. Hydrogen Peroxide Concentrator

    NASA Technical Reports Server (NTRS)

    Parrish, Clyde F.

    2007-01-01

    A relatively simple and economical process and apparatus for concentrating hydrogen peroxide from aqueous solution at the point of use have been invented. The heart of the apparatus is a vessel comprising an outer shell containing tubular membranes made of a polymer that is significantly more permeable by water than by hydrogen peroxide. The aqueous solution of hydrogen peroxide to be concentrated is fed through the interstitial spaces between the tubular membranes. An initially dry sweep gas is pumped through the interiors of the tubular membranes. Water diffuses through the membranes and is carried away as water vapor mixed into the sweep gas. Because of the removal of water, the hydrogen peroxide solution flowing from the vessel at the outlet end is more concentrated than that fed into the vessel at the inlet end. The sweep gas can be air, nitrogen, or any other gas that can be conveniently supplied in dry form and does not react chemically with hydrogen peroxide.

  16. Thermal cloak-concentrator

    NASA Astrophysics Data System (ADS)

    Shen, Xiangying; Li, Ying; Jiang, Chaoran; Ni, Yushan; Huang, Jiping

    2016-07-01

    For macroscopically manipulating heat flow at will, thermal metamaterials have opened a practical way, which possesses a single function, such as either cloaking or concentrating the flow of heat even though environmental temperature varies. By developing a theory of transformation heat transfer for multiple functions, here we introduce the concept of intelligent thermal metamaterials with a dual function, which is in contrast to the existing thermal metamaterials with single functions. By assembling homogeneous isotropic materials and shape-memory alloys, we experimentally fabricate a kind of intelligent thermal metamaterials, which can automatically change from a cloak (or concentrator) to a concentrator (or cloak) when the environmental temperature changes. This work paves an efficient way for a controllable gradient of heat, and also provides guidance both for arbitrarily manipulating the flow of heat and for efficiently designing similar intelligent metamaterials in other fields.

  17. Nebulization reflux concentrator

    NASA Technical Reports Server (NTRS)

    Collins, V. G.; Cofer, W. R., III

    1986-01-01

    A nebulization reflux concentrator for removing trace gas contaminants from a sample gas is described. Sample gas from a gas supply is drawn by a suction source into a vessel. The gas enters the vessel through an atomizing nozzle, thereby atomizing and entraining a scrubbing liquid solvent drawn through a siphon tube from a scrubbing liquid reservoir. The gas and entrained liquid rise through a concentrator and impinge upon a solvent phobic filter, whereby purified gas exits through the filter housing and contaminated liquid coalesces on the solvent phobic filter and falls into the reservoir.

  18. Carney complex.

    PubMed

    Espiard, Stéphanie; Bertherat, Jérôme

    2013-01-01

    Carney complex is a rare, dominantly inherited multiple endocrine neoplasia syndrome, affecting endocrine glands as the adrenal cortex (causing Cushing's syndrome), the pituitary and the thyroid. It is associated with many other nonendocrine tumors, including cardiac myxomas, testicular tumors, melanotic schwannoma, breast myxomatosis, and abnormal pigmentation (lentiginosis) or myxomas of the skin. The gene located on the CNC1 locus was identified 12 years ago as the regulatory subunit 1A (R1A) of the protein kinase A (PRKAR1A) located at 17q22-24. Inactivating heterozygous germline mutations of PRKAR1A are observed in about two thirds of Carney complex patients with some genotype-phenotype correlation useful for follow-up and prognosis. More rarely, mutations of phosphodiesterase genes have been reported in patients presenting mainly with Cushing's syndrome. In vitro and in vivo studies help to understand how R1A inactivation leads to tumorigenesis. PRKAR1A appears to be a relatively weak tumorigenic signal which can cooperate with other signaling pathways and tumor suppressors. PMID:23652670

  19. Dilution, Concentration, and Flotation

    ERIC Educational Resources Information Center

    Liang, Ling; Schmuckler, Joseph S.

    2004-01-01

    As both classroom teaching practice and literature show, many students have difficulties learning science concepts such as density. Here are some investigations that identify the relationship between density and floating through experimenting with successive dilution of a liquid, or the systematic change of concentration of a saltwater solution.…

  20. Parabolic solar concentrator

    NASA Astrophysics Data System (ADS)

    Tecpoyotl-Torres, M.; Campos-Alvarez, J.; Tellez-Alanis, F.; Sánchez-Mondragón, J.

    2006-08-01

    In this work we present the basis of the solar concentrator design, which has is located at Temixco, Morelos, Mexico. For this purpose, this place is ideal due to its geographic and climatic conditions, and in addition, because it accounts with the greatest constant illumination in Mexico. For the construction of the concentrator we use a recycled parabolic plate of a telecommunications satellite dish (NEC). This plate was totally covered with Aluminum. The opening diameter is of 332 cm, the focal length is of 83 cm and the opening angle is of 90°. The geometry of the plate guaranties that the incident beams, will be collected at the focus. The mechanical treatment of the plate produces an average reflectance of 75% in the visible region of the solar spectrum, and of 92% for wavelengths up to 3μm in the infrared region. We obtain up to 2000°C of temperature concentration with this setup. The reflectance can be greatly improved, but did not consider it as typical practical use. The energy obtained can be applied to conditions that require of those high calorific energies. In order to optimize the operation of the concentrator we use a control circuit designed to track the apparent sun position.

  1. Concentrating Tripartite Quantum Information

    NASA Astrophysics Data System (ADS)

    Streltsov, Alexander; Lee, Soojoon; Adesso, Gerardo

    2015-07-01

    We introduce the concentrated information of tripartite quantum states. For three parties Alice, Bob, and Charlie, it is defined as the maximal mutual information achievable between Alice and Charlie via local operations and classical communication performed by Charlie and Bob. We derive upper and lower bounds to the concentrated information, and obtain a closed expression for it on several classes of states including arbitrary pure tripartite states in the asymptotic setting. We show that distillable entanglement, entanglement of assistance, and quantum discord can all be expressed in terms of the concentrated information, thus revealing its role as a unifying informational primitive. We finally investigate quantum state merging of mixed states with and without additional entanglement. The gap between classical and quantum concentrated information is proven to be an operational figure of merit for mixed state merging in the absence of additional entanglement. Contrary to the pure state merging, our analysis shows that classical communication in both directions can provide an advantage for merging of mixed states.

  2. Scattering Solar Thermal Concentrators

    SciTech Connect

    Giebink, Noel C.

    2015-01-31

    This program set out to explore a scattering-based approach to concentrate sunlight with the aim of improving collector field reliability and of eliminating wind loading and gross mechanical movement through the use of a stationary collection optic. The approach is based on scattering sunlight from the focal point of a fixed collection optic into the confined modes of a sliding planar waveguide, where it is transported to stationary tubular heat transfer elements located at the edges. Optical design for the first stage of solar concentration, which entails focusing sunlight within a plane over a wide range of incidence angles (>120 degree full field of view) at fixed tilt, led to the development of a new, folded-path collection optic that dramatically out-performs the current state-of-the-art in scattering concentration. Rigorous optical simulation and experimental testing of this collection optic have validated its performance. In the course of this work, we also identified an opportunity for concentrating photovoltaics involving the use of high efficiency microcells made in collaboration with partners at the University of Illinois. This opportunity exploited the same collection optic design as used for the scattering solar thermal concentrator and was therefore pursued in parallel. This system was experimentally demonstrated to achieve >200x optical concentration with >70% optical efficiency over a full day by tracking with <1 cm of lateral movement at fixed latitude tilt. The entire scattering concentrator waveguide optical system has been simulated, tested, and assembled at small scale to verify ray tracing models. These models were subsequently used to predict the full system optical performance at larger, deployment scale ranging up to >1 meter aperture width. Simulations at an aperture widths less than approximately 0.5 m with geometric gains ~100x predict an overall optical efficiency in the range 60-70% for angles up to 50 degrees from normal. However, the

  3. The concentration camp syndrome.

    PubMed

    Bower, H

    1994-09-01

    A psychiatric syndrome following overwhelming stress after an interval of more than thirty years is described in holocaust survivors who had claimed compensation for persecution between 1939 and 1945. Five nuclear symptom complexes emerge: depressive reactions; anxiety states; somatic complaints; subjective intellectual impairment; and contact abnormalities. Subjects who had experienced persecution during their childhood exhibited contact abnormalities of an aggressive type three times as often as survivors who had suffered an identical trauma as adults. PMID:7893231

  4. Contraception-related deep venous thrombosis and pulmonary embolism in a 17-Year-old girl heterozygous for factor V leiden, prothrombin G20210A mutation, MTHFR C677T and homozygous for PAI-1 mutation: report of a family with multiple genetic risk factors and review of the literature.

    PubMed

    Lenicek Krleza, Jasna; Jakovljevic, Gordana; Bronic, Ana; Coen Herak, Désirée; Bonevski, Aleksandra; Stepan-Giljevic, Jasminka; Roic, Goran

    2010-01-01

    We present the case of a 17-year-old girl who suddenly woke up with localized pain in the left groin and the inability to twist her leg. After comprehensive physician and laboratory examinations, deep venous thrombosis with consequent pulmonary embolism was ascertained. She had not experienced any recent trauma, but she had started to take oral contraceptives 6 months prior to the onset of the symptoms. Her parents and sisters had been asymptomatic throughout their lives, but the family history revealed a few thromboembolic accidents. Using DNA analysis, heterozygosity for factor V Leiden, prothrombin gene mutation G20210A and methylenetetrahydrofolate reductase C677T, as well as the homozygous 4G/4G genotype in the plasminogen activator inhibitor 1 were identified in our patient. Subsequently, DNA analysis was performed in all living family members, and multiple factors associated with thrombophilia were discovered. Our case confirms the multifactorial cause of thromboembolic events and emphasizes the importance of oral contraceptive use in the onset of venous thrombosis, especially in teenage females. In addition, this case indicates that teenage females with a family history of thrombosis who are making choices about contraception could most likely benefit from advanced thrombophilia testing. PMID:20664190

  5. Concentric Split Flow Filter

    NASA Technical Reports Server (NTRS)

    Stapleton, Thomas J. (Inventor)

    2015-01-01

    A concentric split flow filter may be configured to remove odor and/or bacteria from pumped air used to collect urine and fecal waste products. For instance, filter may be designed to effectively fill the volume that was previously considered wasted surrounding the transport tube of a waste management system. The concentric split flow filter may be configured to split the air flow, with substantially half of the air flow to be treated traveling through a first bed of filter media and substantially the other half of the air flow to be treated traveling through the second bed of filter media. This split flow design reduces the air velocity by 50%. In this way, the pressure drop of filter may be reduced by as much as a factor of 4 as compare to the conventional design.

  6. Plasma concentrations of benzodiazepines.

    PubMed Central

    Bond, A J; Hailey, D M; Lader, M H

    1977-01-01

    1. Twenty anxious patients were treated with medazepam, diazepam, chlordiazepoxide, amylobarbitone and placebo, each given in flexible dosage for 2-4 weeks. 2. At the end of each treatment, a series of clinical, physiological and behavioural variables were measured and plasma samples were taken for estimation of the appropriate drug and metabolite concentrations. 3. Nordiazepam was shown to be an important metabolite of both medazepam and diazepam: the ratio of medazepam to noradiazepam was 0.14 and the ratio of diazepam to nordiazepam following diazepam administration was 0.72. 4. No significant correlations were found between the plasma concentrations of any of the treatments and the clinical ratings or behavioural measures. 5. Some relationship was shown between levels of medazepam and its physiological effects. PMID:14659

  7. Concentration through large advection

    NASA Astrophysics Data System (ADS)

    Aleja, D.; López-Gómez, J.

    2014-11-01

    In this paper we extend the elegant results of Chen, Lam and Lou [6, Section 2], where a concentration phenomenon was established as the advection blows up, to a general class of adventive-diffusive generalized logistic equations of degenerate type. Our improvements are really sharp as we allow the carrying capacity of the species to vanish in some subdomain with non-empty interior. The main technical devices used in the derivation of the concentration phenomenon are Proposition 3.2 of Cano-Casanova and López-Gómez [5], Theorem 2.4 of Amann and López-Gómez [1] and the classical Harnack inequality. By the relevance of these results in spatial ecology, complete technical details seem imperative, because the proof of Theorem 2.2 of [6] contains some gaps originated by an “optimistic” use of Proposition 3.2 of [5]. Some of the general assumptions of [6] are substantially relaxed.

  8. Solar concentrator materials development

    NASA Technical Reports Server (NTRS)

    Morel, D. E.; Ayers, S. R.; Gulino, D. A.; Tennyson, R. C.; Egger, R. A.

    1986-01-01

    Materials with potential applications in reflective and refractive solar dynamic concentrators are tested for resistance to atomic oxygen degradation. It is found that inorganic coatings such as MgF2, SiO(x), and ITO provide excellent protection for reflective surfaces while organic materials are much more susceptible to erosion and mass loss. Of the organic polymers tested, the silicones have the highest intrinsic resistance to atomic oxygen degradation.

  9. Electrolyte Concentrates Treat Dehydration

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Wellness Brands Inc. of Boulder, Colorado, exclusively licensed a unique electrolyte concentrate formula developed by Ames Research Center to treat and prevent dehydration in astronauts returning to Earth. Marketed as The Right Stuff, the company's NASA-derived formula is an ideal measure for athletes looking to combat dehydration and boost performance. Wellness Brands also plans to expand with products that make use of the formula's effective hydration properties to help treat conditions including heat stroke, altitude sickness, jet lag, and disease.

  10. Venom Concentrations and Clotting Factor Levels in a Prospective Cohort of Russell’s Viper Bites with Coagulopathy

    PubMed Central

    Isbister, Geoffrey K.; Maduwage, Kalana; Scorgie, Fiona E.; Shahmy, Seyed; Mohamed, Fahim; Abeysinghe, Chandana; Karunathilake, Harendra; O’Leary, Margaret A.; Gnanathasan, Christeine A.; Lincz, Lisa F.

    2015-01-01

    Background Russell’s viper envenoming is a major problem in South Asia and causes venom induced consumption coagulopathy. This study aimed to investigate the kinetics and dynamics of venom and clotting function in Russell’s viper envenoming. Methodology/Principal Findings In a prospective cohort of 146 patients with Russell’s viper envenoming, we measured venom concentrations, international normalised ratio [INR], prothrombin time (PT), activated partial thromboplastin time (aPTT), coagulation factors I, II, V, VII, VIII, IX and X, and von Willebrand factor antigen. The median age was 39y (16–82y) and 111 were male. The median peak INR was 6.8 (interquartile range[IQR]:3.7 to >13), associated with low fibrinogen [median,<0.01g/L;IQR:<0.01–0.9g/L), low factor V levels [median,<5%;IQR:<5–4%], low factor VIII levels [median,40%;IQR:12–79%] and low factor X levels [median,48%;IQR:29–67%]. There were smaller reductions in factors II, IX and VII over time. All factors recovered over 48h post-antivenom. The median INR remained >3 at 6h post-antivenom but had reduced to <2, by 24h. The aPTT had also returned to close to normal (<50sec) at 24h. Factor VII, VIII and IX levels were unusually high pre-antivenom, median peak concentrations of 393%, 307% and 468% respectively. Pre-antivenom venom concentrations and the INR (r = 0.20, p = 0.02) and aPTT (r = 0.19, p = 0.03) were correlated (non-parametric Spearman analysis). Conclusions Russell’s viper coagulopathy results in prolonged aPTT, INR, low fibrinogen, factors V, VIII and X which recover over 48h. Severity of clotting abnormalities was associated with venom concentrations. PMID:26296235

  11. Toward Localized In Vivo Biomarker Concentration Measurements

    PubMed Central

    Zhang, Xiaojuan; Reeves, Daniel; Shi, Yipeng; Gimi, Barjor; Nemani, Krishnamurthy V.; Perreard, Irina M.; Toraya-Brown, Seiko; Fiering, Steven; Weaver, John B.

    2015-01-01

    We know a great deal about the biochemistry of cells because they can be isolated and studied. The biochemistry of the much more complex in vivo environment is more difficult to study because the only ways to quantitate concentrations is to sacrifice the animal or biopsy the tissue. Either method disrupts the environment profoundly and neither method allows longitudinal studies on the same individual. Methods of measuring chemical concentrations in vivo are very valuable alternatives to sacrificing groups of animals. We are developing microscopic magnetic nanoparticle (mNP) probes to measure the concentration of a selected molecule in vivo. The mNPs are targeted to bind the selected molecule and the resulting reduction in rotational freedom can be quantified remotely using magnetic spectroscopy. The mNPs must be contained in micrometer sized porous shells to keep them from migrating and to protect them from clearance by the immune system. There are two key issues in the development of the probes. First, we demonstrate the ability to measure concentrations in the porous walled alginate probes both in phosphate buffered saline and in blood, which is an excellent surrogate for the complex and challenging in vivo environment. Second, sensitivity is critical because it allows microscopic probes to measure very small concentrations very far away. We report sensitivity measurements on recently introduced technology that has allowed us to improve the sensitivity by two orders of magnitude, a factor of 200 so far. PMID:26203196

  12. Spectroscopy of plutonium-organic complexes

    SciTech Connect

    Richmann, M.K.; Reed, D.T.

    1995-12-31

    Information on the spectroscopy of plutonium-organic complexes is needed to help establish the speciation of these complexes under environmentally relevant conditions. Laser photoacoustic spectroscopy (LPAS) and absorption spectrometry were used to characterize the Pu(IV)-citrate and Pu(IV)-nitrilotriacetic acid (NTA) complexes at concentrations of 10{sup {minus}3}--10{sup {minus}7} M in aqueous solution. Good agreement was observed between the band shape of the LPAS and absorption spectra for the Pu(IV)-NTA complex. Agreement for the Pu(IV)-citrate complex was not quite as good. In both cases, a linear dependence of the LPAS signal on laser power and total concentration of the complexes was noted. This work is part of an ongoing research effort to study key subsurface interactions of plutonium-organic complexes.

  13. Phytochelatin concentrations in the equatorial Pacific

    NASA Astrophysics Data System (ADS)

    Ahner, Beth A.; Lee, Jennifer G.; Price, Neil M.; Morel, François M. M.

    1998-11-01

    . The differences between metal additions and controls were greater within the upwelling zone, where water presumably has had less time to accumulate biogenic complexing agents. However, the uniformity of phytochelatin concentrations in and out of the upwelling region suggests that the phytoplankton or the biota are successfully maintaining a tight control over the trace metal chemistry both intra- and extracellularly across a wide range of oceanic conditions.

  14. Limit of concentration for cylindrical concentrators under extended light sources.

    PubMed

    Miñano, J C; Luque, A

    1983-08-15

    Cylindrical concentrators illuminated by an extended source with an arbitrary distribution of radiance are analyzed taking into account basic properties derived from the Fermat principle and not from the specific concentrator shape. The upper limit of concentration achievable with this type of concentrator is obtained and it is found to be lower than that of general (3-D) concentrators. Cylindrical compound parabolic concentrators are analyzed in the light of this theory, and it is shown that they achieve the highest optical concentration possible for a cylindrical concentrator. PMID:18196152

  15. [Complex posttraumatic stress disorder].

    PubMed

    Green, Tamar; Kotler, Moshe

    2007-11-01

    The characteristic symptoms resulting from exposure to an extreme trauma include three clusters of symptoms: persistent experience of the traumatic event, persistent avoidance of stimuli associated with the trauma and persistent symptoms of increased arousal. Beyond the accepted clusters of symptoms for posttraumatic stress disorder exists a formation of symptoms related to exposure to extreme or prolonged stress e.g. childhood abuse, physical violence, rape, and confinement within a concentration camp. With accumulated evidence of the existence of these symptoms began a trail to classify a more complex syndrome, which included, but was not confined to the symptoms of posttraumatic stress disorder. This review addresses several subjects for study in complex posttraumatic stress disorder, which is a complicated and controversial topic. Firstly, the concept of complex posttraumatic stress disorder is presented. Secondly, the professional literature relevant to this disturbance is reviewed and finally, the authors present the polemic being conducted between the researchers of posttraumatic disturbances regarding validity, reliability and the need for separate diagnosis for these symptoms. PMID:18087837

  16. [Carney complex].

    PubMed

    Losada Grande, Eladio José; Al Kassam Martínez, Daniel; González Boillos, Margarita

    2011-01-01

    Carney complex (CNC) is an autosomal dominantly inherited syndrome characterized by spotty skin pigmentation, cardiac and cutaneous myxoma, and endocrine overactivity. Skin pigmentation includes lentigines and blue nevi. Myxomas may occur in breast, skin and heart. Cardiac myxomas may be multiple and occur in any cardiac chamber, and are more prone to recurrence. The most common endocrine gland manifestation is an ACTH-independent Cushing's syndrome due to primary pigmented nodular adrenocortical disease (PPNAD). PPNAD may occur isolated, with no other signs of CNC. Pituitary and thyroid glands and gonads are also involved. The PRKAR1A gene, located in 17 q22-24, encodes type 1A regulatory subunit of protein kinase A. Inactivating germline mutations of this gene are found in 70% of patients with CNC. PRKAR1A is a key component of the c-AMP signaling pathway that has been implicated in endocrine tumorigenesis. Many different mutations have been reported in the PRKAR1A gene. In almost all cases the sequence change was predicted to lead to a premature stop codon and the resultant mutant mRNA was subject to nonsense-mediated mRNA decay. There is no clear genotype-phenotype correlation in patients with CNC. Genetic analysis should be performed in all CNC index cases. All affected patients should be monitored for clinical signs of CNC at least once a year. Genetic diagnosis allows for more effective preparation of more appropriate and effective therapeutic strategies and genetic counseling for patients and gene carriers, and to avoid unnecessary tests to relatives not carrying the gene. PMID:21536508

  17. Concentrated Solar Thermoelectric Power

    SciTech Connect

    Chen, Gang; Ren, Zhifeng

    2015-07-09

    The goal of this project is to demonstrate in the lab that solar thermoelectric generators (STEGs) can exceed 10% solar-to-electricity efficiency, and STEGs can be integrated with phase-change materials (PCM) for thermal storage, providing operation beyond daylight hours. This project achieved significant progress in many tasks necessary to achieving the overall project goals. An accurate Themoelectric Generator (TEG) model was developed, which included realistic treatment of contact materials, contact resistances and radiative losses. In terms of fabricating physical TEGs, high performance contact materials for skutterudite TE segments were developed, along with brazing and soldering methods to assemble segmented TEGs. Accurate measurement systems for determining device performance (in addition to just TE material performance) were built for this project and used to characterize our TEGs. From the optical components’ side, a spectrally selective cermet surface was developed with high solar absorptance and low thermal emittance, with thermal stability at high temperature. A measurement technique was also developed to determine absorptance and total hemispherical emittance at high temperature, and was used to characterize the fabricated spectrally selective surfaces. In addition, a novel reflective cavity was designed to reduce radiative absorber losses and achieve high receiver efficiency at low concentration ratios. A prototype cavity demonstrated that large reductions in radiative losses were possible through this technique. For the overall concentrating STEG system, a number of devices were fabricated and tested in a custom built test platform to characterize their efficiency performance. Additionally, testing was performed with integration of PCM thermal storage, and the storage time of the lab scale system was evaluated. Our latest testing results showed a STEG efficiency of 9.6%, indicating promising potential for high performance concentrated STEGs.

  18. PFC concentration and recycle

    SciTech Connect

    Tom, G.M.; McManus, J.; Knolle, W.; Stoll, I.

    1994-12-31

    The semiconductor industry uses PFC gases such as CF{sub 4} and C{sub 2}F{sub 6} as etchant and cleaning gases during plasma processes. The gases do not fully react within the reactor chamber. The unused gases enter the atmosphere through the process effluent. These gases have long persistence in the atmosphere and absorb infrared radiation. The PFC gases are, therefore, potential global warming gases. A method is described that will recover and recycle PFC gases. The method that the authors have employed to trap and concentrate the PFC gases is based on a dual bed adsorber. The adsorption material is activated carbon.

  19. Characterization of Photovoltaic Concentrators

    SciTech Connect

    Kiehl, J.; Emery, E.

    2005-01-01

    This paper will describe the resources at the National Renewable Energy Laboratory (NREL) for performing characterization of photovoltaic (PV) materials designed for operation under concentrated light. NREL has the capability to measure devices ranging from very small, unencapsulated research cells to reasonably sized, environmentally protected modules. Data gathering and interpretation are also ongoing areas of revision and improvement. The main goal of the current research is to reduce the measurement uncertainty to the lowest practical value. At present, the state of the art is limited at a ?5% level in measuring efficiency accurately.

  20. METHOD OF ISOTOPE CONCENTRATION

    DOEpatents

    Taylor, T.I.; Spindel, W.

    1960-02-01

    A method of concentrating N/sup 15/ in a liquid is described. Gaseous nitric oxide and at least one liquid selected from the group consisting of the aqueous oxyacids and oxides of nitrogen, wherein the atomic ratio of oxygen to nitrogen is greater than unity, are brought into intimate contact to cause an enrichment of the liquid and a depletion of the gas in N/sup 15/. The liquid is, thereafter, reacted with sulfur dioxide to produce a gas contuining nitric oxide. The gas contuining nitric oxide is then continuously passed in countercurrent contact with the liquid to cause further enrichment of the liquid.

  1. Vapor concentration monitor

    DOEpatents

    Bayly, John G.; Booth, Ronald J.

    1977-01-01

    An apparatus for monitoring the concentration of a vapor, such as heavy water, having at least one narrow bandwidth in its absorption spectrum, in a sample gas such as air. The air is drawn into a chamber in which the vapor content is measured by means of its radiation absorption spectrum. High sensitivity is obtained by modulating the wavelength at a relatively high frequency without changing its optical path, while high stability against zero drift is obtained by the low frequency interchange of the sample gas to be monitored and of a reference sample. The variable HDO background due to natural humidity is automatically corrected.

  2. Effect of stress concentrations in composite structures

    NASA Technical Reports Server (NTRS)

    Babcock, G. D.; Knauss, W. G.

    1984-01-01

    The goal of achieving a better understanding of the failure of complex composite structure is sought. This type of structure requires a thorough understanding of the behavior under load both on a macro and micro scale if failure mechanisms are to be understood. The two problems being studied are the failure at a panel/stiffener interface and a generic problem of failure at a stress concentration.

  3. Optical oxygen concentration monitor

    DOEpatents

    Kebabian, Paul

    1997-01-01

    A system for measuring and monitoring the concentration of oxygen uses as a light source an argon discharge lamp, which inherently emits light with a spectral line that is close to one of oxygen's A-band absorption lines. In a preferred embodiment, the argon line is split into sets of components of shorter and longer wavelengths by a magnetic field of approximately 2000 Gauss that is parallel to the light propagation from the lamp. The longer wavelength components are centered on an absorption line of oxygen and thus readily absorbed, and the shorter wavelength components are moved away from that line and minimally absorbed. A polarization modulator alternately selects the set of the longer wavelength, or upshifted, components or the set of the shorter wavelength, or downshifted, components and passes the selected set to an environment of interest. After transmission over a path through that environment, the transmitted optical flux of the argon line varies as a result of the differential absorption. The system then determines the concentration of oxygen in the environment based on the changes in the transmitted optical flux between the two sets of components. In alternative embodiments modulation is achieved by selectively reversing the polarity of the magnetic field or by selectively supplying the magnetic field to either the emitting plasma of the lamp or the environment of interest.

  4. Optical oxygen concentration monitor

    DOEpatents

    Kebabian, P.

    1997-07-22

    A system for measuring and monitoring the concentration of oxygen uses as a light source an argon discharge lamp, which inherently emits light with a spectral line that is close to one of oxygen`s A-band absorption lines. In a preferred embodiment, the argon line is split into sets of components of shorter and longer wavelengths by a magnetic field of approximately 2,000 Gauss that is parallel to the light propagation from the lamp. The longer wavelength components are centered on an absorption line of oxygen and thus readily absorbed, and the shorter wavelength components are moved away from that line and minimally absorbed. A polarization modulator alternately selects the set of the longer wavelength, or upshifted, components or the set of the shorter wavelength, or downshifted, components and passes the selected set to an environment of interest. After transmission over a path through that environment, the transmitted optical flux of the argon line varies as a result of the differential absorption. The system then determines the concentration of oxygen in the environment based on the changes in the transmitted optical flux between the two sets of components. In alternative embodiments modulation is achieved by selectively reversing the polarity of the magnetic field or by selectively supplying the magnetic field to either the emitting plasma of the lamp or the environment of interest. 4 figs.

  5. Pharmacological properties and pathophysiological significance of a Kunitz-type protease inhibitor (Rusvikunin-II) and its protein complex (Rusvikunin complex) purified from Daboia russelii russelii venom.

    PubMed

    Mukherjee, Ashis K; Mackessy, Stephen P

    2014-10-01

    A 7.1 kDa basic peptide (Rusvikunin-II) was purified from a previously described protein complex (Rusvikunin complex, consists of Rusvikunin and Rusvikunin-II) of Daboia russelii russelii venom. The N-terminal sequence of Rusvikunin-II was found to be blocked, but peptide mass fingerprinting analysis indicated its identity as Kunitz-type basic protease inhibitor 2, previously reported from Russell's Viper venom. A tryptic peptide sequence of Rusvikunin-II containing the N-terminal sequence HDRPTFCNLFPESGR demonstrated significant sequence homology to venom basic protease inhibitors, Kunitz-type protease inhibitors and trypsin inhibitors. The secondary structure of Rusvikunin-II was dominated by β-sheets (60.4%), followed by random coil (38.2%), whereas α-helix (1.4%) contributes the least to its secondary structure. Both Rusvikunin-II and the Rusvikunin complex demonstrated dose-dependent anticoagulant activity; however, the anticoagulant potency of latter was found to be higher. Both inhibited the amidolytic activity of trypsin > plasmin > FXa, fibrinogen clotting activity of thrombin, and, to a lesser extent, the prothrombin activation property of FXa; however, the inhibitory effect of the Rusvikunin complex was more pronounced. Neither Rusvikunin-II nor Rusvikunin complex inhibited the amidolytic activity of chymotrypsin and thrombin. Rusvikunin-II at 10 μg/ml was not cytotoxic to Colo-205, MCF-7 or 3T3 cancer cells; conversely, Rusvikunin complex showed ∼30% reduction of MCF-7 cells under identical experimental conditions. Rusvikunin-II (5.0 mg/kg body weight, i.p. injection) was not lethal to mice or House Geckos; nevertheless, it showed in vivo anticoagulant action in mice. However, the Rusvikunin complex (at 5.0 mg/kg) was toxic to NSA mice, but not to House Geckos, suggesting it has prey-specific toxicity. Rusvikunin complex-treated mice exhibited dyspnea and hind-limb paresis prior to death. The present study indicates that the Kunitz

  6. Non-tracking solar concentrator with a high concentration ratio

    DOEpatents

    Hinterberger, Henry

    1977-01-01

    A nontracking solar concentrator with a high concentration ratio is provided. The concentrator includes a plurality of energy absorbers which communicate with a main header by which absorbed heat is removed. Undesired heat flow of those absorbers not being heated by radiant energy at a particular instant is impeded, improving the efficiency of the concentrator.

  7. Concentrating Solar Power

    NASA Astrophysics Data System (ADS)

    Mehos, Mark

    2008-09-01

    Concentrating Solar Power (CSP) has the potential to contribute significantly to the generation of electricity by renewable energy resources in the U.S.. Thermal storage can extend the duty cycle of CSP beyond daytime hours to early evening where the value of electricity is often the highest. The potential solar resource for the southwest U.S. is identified, along with the need to add power lines to bring the power to consumers. CSP plants in the U.S. and abroad are described. The CSP cost of electricity at the busbar is discussed. With current incentives, CSP is approaching competiveness with conventional gas-fired systems during peak-demand hours when the price of electricity is the highest. It is projected that a mature CSP industry of over 4 GWe will be able to reduce the energy cost by about 50%, and that U.S. capacity could be 120 GW by 2050.

  8. Concentric differential gearing arrangement

    NASA Technical Reports Server (NTRS)

    Zeiger, R. J.; Gerdts, J. C. (Inventor)

    1974-01-01

    Two input members and two concentric rotatable output members are interconnected by a planetary gear arrangement. The first input drives directly the first output. The second input engages a carrier having the planetary gears affixed thereto. Rotation of the carriage causes rotation of the central sun gear of the planetary gear system. The sun gear is journaled to the carriage and is drivingly connected to the second output through a direction reversing set of bevel gears. The first input drive member includes a ring gear drivingly connected to the planetary gears for driving the second output member in the same direction and by the same amount as the first output member. Motion of the first input results in equal motion of the two outputs while input motion of the second input results in movement of the second output relative to the first output. This device is useful where non-interacting two-axis control of remote gimbaled systems is required.

  9. Concentrating solar thermal power.

    PubMed

    Müller-Steinhagen, Hans

    2013-08-13

    In addition to wind and photovoltaic power, concentrating solar thermal power (CSP) will make a major contribution to electricity provision from renewable energies. Drawing on almost 30 years of operational experience in the multi-megawatt range, CSP is now a proven technology with a reliable cost and performance record. In conjunction with thermal energy storage, electricity can be provided according to demand. To date, solar thermal power plants with a total capacity of 1.3 GW are in operation worldwide, with an additional 2.3 GW under construction and 31.7 GW in advanced planning stage. Depending on the concentration factors, temperatures up to 1000°C can be reached to produce saturated or superheated steam for steam turbine cycles or compressed hot gas for gas turbine cycles. The heat rejected from these thermodynamic cycles can be used for sea water desalination, process heat and centralized provision of chilled water. While electricity generation from CSP plants is still more expensive than from wind turbines or photovoltaic panels, its independence from fluctuations and daily variation of wind speed and solar radiation provides it with a higher value. To become competitive with mid-load electricity from conventional power plants within the next 10-15 years, mass production of components, increased plant size and planning/operating experience will be accompanied by technological innovations. On 30 October 2009, a number of major industrial companies joined forces to establish the so-called DESERTEC Industry Initiative, which aims at providing by 2050 15 per cent of European electricity from renewable energy sources in North Africa, while at the same time securing energy, water, income and employment for this region. Solar thermal power plants are in the heart of this concept. PMID:23816910

  10. Stoichiometries of arsenazo III-Ca complexes.

    PubMed Central

    Palade, P; Vergara, J

    1983-01-01

    The equilibrium interactions of the metallochromic indicator arsenazo III with calcium at physiological ionic strength and pH were investigated spectrophotometrically and with the aid of a calcium electrode. Evidence suggests the formation of more than one dye-calcium complex. The analysis of data obtained over a 10,000-fold range of dye concentrations concludes that at the concentrations used for in vitro biochemical studies (10--100 microM), arsenazo III absorbance changes in response to calcium binding primarily involve the formation of a complex involving two dye molecules and two calcium ions. At millimolar dye concentrations, typical of physiological calcium transient determinations in situ, a second complex involving two arsenazo III molecules and one calcium ion is additionally formed. A third complex, involving one arsenazo III molecule and one calcium ion, is formed at very low dye concentrations. The results reported here suggest that equilibrium calibration of the dye with calcium cannot be used directly to satisfactorily relate transient absorbance changes in physiological preparations to calcium concentration changes since several stoichiometrically distinct complexes with different absorbances could be formed at different rates. The results of this study do not permit the elucidation of a unique kinetic scheme of arsenazo III complexation with calcium; for this, in vitro kinetic analysis is required. Results of similar analysis of the dye interaction with magnesium are also reported, and these appear compatible with a much simpler model of complexation. PMID:6626673

  11. Complexity matching in neural networks

    NASA Astrophysics Data System (ADS)

    Usefie Mafahim, Javad; Lambert, David; Zare, Marzieh; Grigolini, Paolo

    2015-01-01

    In the wide literature on the brain and neural network dynamics the notion of criticality is being adopted by an increasing number of researchers, with no general agreement on its theoretical definition, but with consensus that criticality makes the brain very sensitive to external stimuli. We adopt the complexity matching principle that the maximal efficiency of communication between two complex networks is realized when both of them are at criticality. We use this principle to establish the value of the neuronal interaction strength at which criticality occurs, yielding a perfect agreement with the adoption of temporal complexity as criticality indicator. The emergence of a scale-free distribution of avalanche size is proved to occur in a supercritical regime. We use an integrate-and-fire model where the randomness of each neuron is only due to the random choice of a new initial condition after firing. The new model shares with that proposed by Izikevich the property of generating excessive periodicity, and with it the annihilation of temporal complexity at supercritical values of the interaction strength. We find that the concentration of inhibitory links can be used as a control parameter and that for a sufficiently large concentration of inhibitory links criticality is recovered again. Finally, we show that the response of a neural network at criticality to a harmonic stimulus is very weak, in accordance with the complexity matching principle.

  12. Workplace Concentration of Immigrants

    PubMed Central

    Andersson, Fredrik; García-Pérez, Mónica; Haltiwanger, John; McCue, Kristin; Sanders, Seth

    2014-01-01

    Casual observation suggests that in most U.S. urban labor markets, immigrants have more immigrant coworkers than native-born workers do. While seeming obvious, this excess tendency to work together has not been precisely measured, nor have its sources been quantified. Using matched employer–employee data from the U.S. Census Bureau Longitudinal Employer-Household Dynamics (LEHD) database on a set of metropolitan statistical areas (MSAs) with substantial immigrant populations, we find that, on average, 37% of an immigrant’s coworkers are themselves immigrants; in contrast, only 14% of a native-born worker’s coworkers are immigrants. We decompose this difference into the probability of working with compatriots versus with immigrants from other source countries. Using human capital, employer, and location characteristics, we narrow the mechanisms that might explain immigrant concentration. We find that industry, language, and residential segregation collectively explain almost all the excess tendency to work with immigrants from other source countries, but they have limited power to explain work with compatriots. This large unexplained compatriot component suggests an important role for unmeasured country-specific factors, such as social networks. PMID:25425452

  13. Workplace concentration of immigrants.

    PubMed

    Andersson, Fredrik; García-Pérez, Mónica; Haltiwanger, John; McCue, Kristin; Sanders, Seth

    2014-12-01

    Casual observation suggests that in most U.S. urban labor markets, immigrants have more immigrant coworkers than native-born workers do. While seeming obvious, this excess tendency to work together has not been precisely measured, nor have its sources been quantified. Using matched employer-employee data from the U.S. Census Bureau Longitudinal Employer-Household Dynamics (LEHD) database on a set of metropolitan statistical areas (MSAs) with substantial immigrant populations, we find that, on average, 37 % of an immigrant's coworkers are themselves immigrants; in contrast, only 14 % of a native-born worker's coworkers are immigrants. We decompose this difference into the probability of working with compatriots versus with immigrants from other source countries. Using human capital, employer, and location characteristics, we narrow the mechanisms that might explain immigrant concentration. We find that industry, language, and residential segregation collectively explain almost all the excess tendency to work with immigrants from other source countries, but they have limited power to explain work with compatriots. This large unexplained compatriot component suggests an important role for unmeasured country-specific factors, such as social networks. PMID:25425452

  14. Photovoltaic solar concentrator module

    SciTech Connect

    Chiang, C.J.

    1991-05-16

    This invention consists of a planar photovoltaic concentrator module for producing an electrical signal from incident solar radiation which includes an electrically insulating housing having a front wall, an opposing back wall and a hollow interior. A solar cell having electrical terminals is positioned within the interior of the housing. A planar conductor is connected with a terminal of the solar cell of the same polarity. A lens forming the front wall of the housing is operable to direct solar radiation incident to the lens into the interior of the housing. A refractive optical element in contact with the solar cell and facing the lens receives the solar radiation directed into the interior of the housing by the lens and directs the solar radiation to the solar cell to cause the solar cell to generate an electrical signal. An electrically conductive planar member is positioned in the housing to rest on the housing back wall in supporting relation with the solar cell terminal of opposite polarity. The planar member is operable to dissipate heat radiated by the solar cell as the solar cell generates an electrical signal and further forms a solar cell conductor connected with the solar cell terminal to permit the electrical signal generated by the solar cell to be measured between the planar member and the conductor.

  15. Concentric tube support assembly

    DOEpatents

    Rubio, Mark F.; Glessner, John C.

    2012-09-04

    An assembly (45) includes a plurality of separate pie-shaped segments (72) forming a disk (70) around a central region (48) for retaining a plurality of tubes (46) in a concentrically spaced apart configuration. Each segment includes a support member (94) radially extending along an upstream face (96) of the segment and a plurality of annularly curved support arms (98) transversely attached to the support member and radially spaced apart from one another away from the central region for receiving respective upstream end portions of the tubes in arc-shaped spaces (100) between the arms. Each segment also includes a radial passageway (102) formed in the support member for receiving a fluid segment portion (106) and a plurality of annular passageways (104) formed in the support arms for receiving respective arm portions (108) of the fluid segment portion from the radial passageway and for conducting the respective arm portions into corresponding annular spaces (47) formed between the tubes retained by the disk.

  16. 1. West facade of Plutonium Concentration Facility (Building 233S), ReductionOxidation ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. West facade of Plutonium Concentration Facility (Building 233-S), Reduction-Oxidation Building (REDOX-202-S) to the right. Looking east. - Reduction-Oxidation Complex, Plutonium Concentration Facility, 200 West Area, Richland, Benton County, WA

  17. On State Complexes and Special Cube Complexes

    ERIC Educational Resources Information Center

    Peterson, Valerie J.

    2009-01-01

    This thesis presents the first steps toward a classification of non-positively curved cube complexes called state complexes. A "state complex" is a configuration space for a "reconfigurable system," i.e., an abstract system in which local movements occur in some discrete manner. Reconfigurable systems can be used to describe, for example,…

  18. Metallization problems with concentrator cells

    NASA Technical Reports Server (NTRS)

    Iles, P. A.

    1983-01-01

    Cells used with concentrators have similar contact requirements to other cells, but operation at high intensity imposes more than the usual demands on the metallization. Overall contact requirements are listed and concentrator cell requirements are discussed.

  19. Markets for concentrating solar power

    SciTech Connect

    Not Available

    1998-04-01

    The report describes the markets for concentrating solar power. As concentrating solar power technologies advance into the early stages of commercialization, their economic potential becomes more sharply defined and increasingly tangible.

  20. Conical electromagnetic radiation flux concentrator

    NASA Technical Reports Server (NTRS)

    Miller, E. R.

    1972-01-01

    Concentrator provides method of concentrating a beam of electromagnetic radiation into a smaller beam, presenting a higher flux density. Smaller beam may be made larger by sending radiation through the device in the reverse direction.

  1. Microsheet Glass In Solar Concentrators

    NASA Technical Reports Server (NTRS)

    Richter, Scott W.

    1993-01-01

    Microsheet glass used as highly protective covering material for developmental concentrating reflectors for solar power systems. Together with other materials, possible to fabricate lightweight, highly reflective, accurate, and long-lived concentrators. Desirable properties include durability and smoothness. Glass not affected by ultraviolet radiation, and not degraded by atomic oxygen, found in low orbits around Earth. Though concentrators intended for use in outer space, noteworthy that terrestrial concentrator fabricated with glass sheet 0.7 mm thick.

  2. Complex Fluids and Hydraulic Fracturing.

    PubMed

    Barbati, Alexander C; Desroches, Jean; Robisson, Agathe; McKinley, Gareth H

    2016-06-01

    Nearly 70 years old, hydraulic fracturing is a core technique for stimulating hydrocarbon production in a majority of oil and gas reservoirs. Complex fluids are implemented in nearly every step of the fracturing process, most significantly to generate and sustain fractures and transport and distribute proppant particles during and following fluid injection. An extremely wide range of complex fluids are used: naturally occurring polysaccharide and synthetic polymer solutions, aqueous physical and chemical gels, organic gels, micellar surfactant solutions, emulsions, and foams. These fluids are loaded over a wide range of concentrations with particles of varying sizes and aspect ratios and are subjected to extreme mechanical and environmental conditions. We describe the settings of hydraulic fracturing (framed by geology), fracturing mechanics and physics, and the critical role that non-Newtonian fluid dynamics and complex fluids play in the hydraulic fracturing process. PMID:27070765

  3. Bronchial secretion concentrations of tobramycin.

    PubMed

    Alexander, M R; Schoell, J; Hicklin, G; Kasik, J E; Coleman, D

    1982-02-01

    The mean concentrations of tobramycin in bronchial secretions from patients with pneumonia were almost two times greater than secretions from patients free of lung infection. Mean tobramycin bronchial secretion to serum concentration ratios also were higher when obtained from infected lungs (0.66 versus 0.17) These data suggest that lung infection enhances the concentrations of tobramycin in bronchial secretions. PMID:7065524

  4. Antischistosomal Activity of Oxindolimine-Metal Complexes

    PubMed Central

    Dario, Bruno S.; Couto, Ricardo A. A.; Pinto, Pedro L. S.; da Costa Ferreira, Ana M.

    2015-01-01

    In recent years, a class of oxindole-copper and -zinc complex derivatives have been reported as compounds with efficient proapoptotic activity toward different tumor cells (e.g., neuroblastomas, melanomas, monocytes). Here we assessed the efficacy of synthesized oxindole-copper(II), -zinc(II), and -vanadyl (VO2+) complexes against adult Schistosoma mansoni worms. The copper(II) complexes (50% inhibitory concentrations of 30 to 45 μM) demonstrated greater antischistosomal properties than the analogous zinc and vanadyl complexes regarding lethality, reduction of motor activity, and oviposition. PMID:26239976

  5. Antischistosomal Activity of Oxindolimine-Metal Complexes.

    PubMed

    de Moraes, Josué; Dario, Bruno S; Couto, Ricardo A A; Pinto, Pedro L S; da Costa Ferreira, Ana M

    2015-10-01

    In recent years, a class of oxindole-copper and -zinc complex derivatives have been reported as compounds with efficient proapoptotic activity toward different tumor cells (e.g., neuroblastomas, melanomas, monocytes). Here we assessed the efficacy of synthesized oxindole-copper(II), -zinc(II), and -vanadyl (VO(2+)) complexes against adult Schistosoma mansoni worms. The copper(II) complexes (50% inhibitory concentrations of 30 to 45 μM) demonstrated greater antischistosomal properties than the analogous zinc and vanadyl complexes regarding lethality, reduction of motor activity, and oviposition. PMID:26239976

  6. Modeling the CAPTEX vertical tracer concentration profiles

    SciTech Connect

    Draxler, R.R.; Stunder, B.J.B.

    1988-05-01

    Perfluorocarbon tracer concentration profiles measured by aircraft 600--900 km downwind of the release locations during CAPTEX are discussed and compared with some model results. In general, the concentrations decreased with height in the upper half of the boundary layer where the aircraft measurements were made. The results of a model sensitivity study suggested that the shape of the profile was primarily due to winds increasing with height and relative position of the sampling with respect to the upwind and downwind edge of the plume. Further modeling studies showed that relatively simple vertical mixing parameterizations could account for the complex vertical plume structure when the model had sufficient vertical resolution. In general, the model performed better with slower winds and corresponding longer transport times.

  7. Modeling the CAPTEX Vertical Tracer Concentration Profiles.

    NASA Astrophysics Data System (ADS)

    Draxler, Roland R.; Stunder, Barbara J. B.

    1988-05-01

    Perfluorocarbon tracer concentration profiles measured by aircraft 600-900 km downwind of the release locations during CAPTEX are discussed and compared with some model results. In general, the concentrations decreased with height in the upper half of the boundary layer where the aircraft measurements were made. The results of a model sensitivity study suggested that the shape of the profile was primarily due to winds increasing with height and relative position of the sampling with respect to the upwind and downwind edge of the plume. Further modeling studies showed that relatively simple vertical mixing parameterizations could account for the complex vertical plume structure when the model had sufficient vertical resolution. In general, the model performed better with slower winds and corresponding longer transport times.

  8. Cost analysis of carbon dioxide concentrators

    NASA Technical Reports Server (NTRS)

    Yakut, M. M.

    1973-01-01

    Methodology and cost estimating relationships, for flight-type and prototype CO2 concentrators, have been developed and presented. A validity check was made by comparing the molecular sieves system considered here and that developed for Skylab. The system evaluated here is twice the size of the Skylab system and is also more complex as it desorbs CO2 thermally and stores it in an accumulator. The cost estimates developed were found to be approximately 50 to 70% higher than the actual cost of the Skylab unit.

  9. Concentrator hot-spot testing, phase 1

    NASA Technical Reports Server (NTRS)

    Gonzalez, C. C.

    1987-01-01

    Results of a study to determine the hot-spot susceptibility of concentrator cells, to provide a hot-spot qualification test for concentrator modules, and to provide guidelines for reducing hot-spot susceptibility are presented. Hot-spot heating occurs in a photovoltaic module when the short-circuit current of a cell is lower than the string operating current forcing the cell into reverse bias with a concurrent power dissipation. Although the basis for the concentrator module hot-spot qualification test is the test developed for flat-plate modules, issues, such as providing cell illumination, introduce additional complexities into the testing procedure. The same general guidelines apply for protecting concentrator modules from hot-spot stressing as apply to flat-plate modules. Therefore, recommendations are made on the number of bypass diodes required per given number of series cells per module or source circuit. In addition, a new method for determining the cell temperature in the laboratory or in the field is discussed.

  10. Low concentrator PV optics optimization

    NASA Astrophysics Data System (ADS)

    Sharp, Leonard; Chang, Ben

    2008-08-01

    Purpose: Cost reduction is a major focus of the solar industry. Thin film technologies and concentration systems are viable ways to reducing cost, with unique strengths and weakness for both. Most of the concentrating PV work focuses on high concentration systems for reducing energy cost. Meanwhile, many believe that low concentrators provide significant cost reduction potential while addressing the mainstream PV market with a product that acts as a flat panel replacement. This paper analyzes the relative benefit of asymmetric vs. symmetric optics for low-concentrators in light of specific PV applications. Approach: Symmetric and asymmetric concentrating PV module performance is evaluated using computer simulation to determine potential value across various geographic locations and applications. The selected optic design is modeled against standard cSi flat panels and thin film to determine application fit, system level energy density and economic value. Results: While symmetric designs may seem ideal, asymmetric designs have an advantage in energy density. Both designs are assessed for aperture, optimum concentration ratio, and ideal system array configuration. Analysis of performance across climate specific effects (diffuse, direct and circumsolar) and location specific effects (sunpath) are also presented. The energy density and energy production of low concentrators provide a compelling value proposition. More significantly, the choice of optics for a low concentrating design can affect real world performance. With the goal of maximizing energy density and return on investment, this paper presents the advantages of asymmetric optic concentration and illustrates the value of this design within specific PV applications.

  11. GECluster: a novel protein complex prediction method

    PubMed Central

    Su, Lingtao; Liu, Guixia; Wang, Han; Tian, Yuan; Zhou, Zhihui; Han, Liang; Yan, Lun

    2014-01-01

    Identification of protein complexes is of great importance in the understanding of cellular organization and functions. Traditional computational protein complex prediction methods mainly rely on the topology of protein–protein interaction (PPI) networks but seldom take biological information of proteins (such as Gene Ontology (GO)) into consideration. Meanwhile, the environment relevant analysis of protein complex evolution has been poorly studied, partly due to the lack of high-precision protein complex datasets. In this paper, a combined PPI network is introduced to predict protein complexes which integrate both GO and expression value of relevant protein-coding genes. A novel protein complex prediction method GECluster (Gene Expression Cluster) was proposed based on a seed node expansion strategy, in which a combined PPI network was utilized. GECluster was applied to a training combined PPI network and it predicted more credible complexes than peer methods. The results indicate that using a combined PPI network can efficiently improve protein complex prediction accuracy. In order to study protein complex evolution within cells due to changes in the living environment surrounding cells, GECluster was applied to seven combined PPI networks constructed using the data of a test set including yeast response to stress throughout a wine fermentation process. Our results showed that with the rise of alcohol concentration, protein complexes within yeast cells gradually evolve from one state to another. Besides this, the number of core and attachment proteins within a protein complex both changed significantly. PMID:26019559

  12. Bruise chromophore concentrations over time

    NASA Astrophysics Data System (ADS)

    Duckworth, Mark G.; Caspall, Jayme J.; Mappus, Rudolph L., IV; Kong, Linghua; Yi, Dingrong; Sprigle, Stephen H.

    2008-03-01

    During investigations of potential child and elder abuse, clinicians and forensic practitioners are often asked to offer opinions about the age of a bruise. A commonality between existing methods of bruise aging is analysis of bruise color or estimation of chromophore concentration. Relative chromophore concentration is an underlying factor that determines bruise color. We investigate a method of chromophore concentration estimation that can be employed in a handheld imaging spectrometer with a small number of wavelengths. The method, based on absorbance properties defined by Beer-Lambert's law, allows estimation of differential chromophore concentration between bruised and normal skin. Absorption coefficient data for each chromophore are required to make the estimation. Two different sources of this data are used in the analysis- generated using Independent Component Analysis and taken from published values. Differential concentration values over time, generated using both sources, show correlation to published models of bruise color change over time and total chromophore concentration over time.

  13. Utility-scale photovoltaic concentrators

    SciTech Connect

    None, None

    2009-01-18

    The photovoltaics concentrators section of the Renewable Energy Technology Characterizations describes the technical and economic status of this emerging renewable energy option for electricity supply.

  14. Continuous flow dielectrophoretic particle concentrator

    DOEpatents

    Cummings, Eric B.

    2007-04-17

    A continuous-flow filter/concentrator for separating and/or concentrating particles in a fluid is disclosed. The filter is a three-port device an inlet port, an filter port and a concentrate port. The filter separates particles into two streams by the ratio of their dielectrophoretic mobility to their electrokinetic, advective, or diffusive mobility if the dominant transport mechanism is electrokinesis, advection, or diffusion, respectively.Also disclosed is a device for separating and/or concentrating particles by dielectrophoretic trapping of the particles.

  15. Demonstrating Hemostasis with a Student-Designed Prothrombin Time Test

    ERIC Educational Resources Information Center

    Fardy, Richard Wiley

    1978-01-01

    Describes a blood coagulation test developed by two high school biology students. Although the test lacks some precision, results indicate that the technique is comparable to standard methods used in laboratories. (MA)

  16. Point Defect Concentrations in Metastable Fe-C Alloys

    NASA Astrophysics Data System (ADS)

    Först, Clemens J.; Slycke, Jan; van Vliet, Krystyn J.; Yip, Sidney

    2006-05-01

    Point defect species and concentrations in metastable Fe-C alloys are determined using density functional theory and a constrained free-energy functional. Carbon interstitials dominate unless iron vacancies are in significant excess, whereas excess carbon causes greatly enhanced vacancy concentration. Our predictions are amenable to experimental verification; they provide a baseline for rationalizing complex microstructures known in hardened and tempered steels, and by extension other technological materials created by or subjected to extreme environments.

  17. The complex chemical Langevin equation

    SciTech Connect

    Schnoerr, David; Sanguinetti, Guido; Grima, Ramon

    2014-07-14

    The chemical Langevin equation (CLE) is a popular simulation method to probe the stochastic dynamics of chemical systems. The CLE’s main disadvantage is its break down in finite time due to the problem of evaluating square roots of negative quantities whenever the molecule numbers become sufficiently small. We show that this issue is not a numerical integration problem, rather in many systems it is intrinsic to all representations of the CLE. Various methods of correcting the CLE have been proposed which avoid its break down. We show that these methods introduce undesirable artefacts in the CLE’s predictions. In particular, for unimolecular systems, these correction methods lead to CLE predictions for the mean concentrations and variance of fluctuations which disagree with those of the chemical master equation. We show that, by extending the domain of the CLE to complex space, break down is eliminated, and the CLE’s accuracy for unimolecular systems is restored. Although the molecule numbers are generally complex, we show that the “complex CLE” predicts real-valued quantities for the mean concentrations, the moments of intrinsic noise, power spectra, and first passage times, hence admitting a physical interpretation. It is also shown to provide a more accurate approximation of the chemical master equation of simple biochemical circuits involving bimolecular reactions than the various corrected forms of the real-valued CLE, the linear-noise approximation and a commonly used two moment-closure approximation.

  18. Concentration.

    ERIC Educational Resources Information Center

    Mercogliano, Chris

    1994-01-01

    A teacher describes his experiences during an outdoor expedition with urban students from the Free School in Albany, New York. Time spent at the school's camp is intended to narrow the gap between experience and learning, promote principles of "self-regulation" and "work democracy" encouraging students to manage their own behavior and make…

  19. Plasma Efavirenz Concentrations Are Associated With Lipid and Glucose Concentrations

    PubMed Central

    Sinxadi, Phumla Zuleika; McIlleron, Helen Margaret; Dave, Joel Alex; Smith, Peter John; Levitt, Naomi Sharlene; Haas, David William; Maartens, Gary

    2016-01-01

    Abstract Efavirenz-based antiretroviral therapy (ART) has been associated with dyslipidemia and dysglycemia, risk factors for cardiovascular disease. However, the pathogenesis is not well understood. We characterized relationships between plasma efavirenz concentrations and lipid and glucose concentrations in HIV-infected South Africans. Participants on efavirenz-based ART were enrolled into a cross-sectional study. The oral glucose tolerance test was performed after an overnight fast, and plasma drawn for mid-dosing interval efavirenz, fasting total cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, and triglycerides concentrations. Among 106 participants (77 women), median age was 38 years, median CD4 + T-cell count was 322 cells/μL, median duration on ART was 18 months, and median (interquartile range) efavirenz concentration was 2.23 (1.66 to 4.10) μg/mL. On multivariable analyses (adjusting for age, sex, body mass index, and ART duration) doubling of efavirenz concentrations resulted in mean changes in mmol/L (95%CI) of: total cholesterol (0.40 [0.22 to 0.59]), LDL cholesterol (0.19 [0.04 to 0.30]), HDL cholesterol (0.14 [0.07 to 0.20]), triglycerides (0.17 [0.03 to 0.33]), fasting glucose (0.18 [0.03 to 0.33]), and 2-h glucose concentrations (0.33 [0.08 to 0.60]). Among 57 participants with CYP2B6 genotype data, associations between slow metabolizer genotypes and metabolic profiles were generally consistent with those for measured efavirenz concentrations. Higher plasma efavirenz concentrations are associated with higher plasma lipid and glucose concentrations. This may have implications for long-term cardiovascular complications of efavirenz-based ART, particularly among populations with high prevalence of CYP2B6 slow metabolizer genotypes. PMID:26765416

  20. Plasma Efavirenz Concentrations Are Associated With Lipid and Glucose Concentrations.

    PubMed

    Sinxadi, Phumla Zuleika; McIlleron, Helen Margaret; Dave, Joel Alex; Smith, Peter John; Levitt, Naomi Sharlene; Haas, David William; Maartens, Gary

    2016-01-01

    Efavirenz-based antiretroviral therapy (ART) has been associated with dyslipidemia and dysglycemia, risk factors for cardiovascular disease. However, the pathogenesis is not well understood. We characterized relationships between plasma efavirenz concentrations and lipid and glucose concentrations in HIV-infected South Africans.Participants on efavirenz-based ART were enrolled into a cross-sectional study. The oral glucose tolerance test was performed after an overnight fast, and plasma drawn for mid-dosing interval efavirenz, fasting total cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, and triglycerides concentrations.Among 106 participants (77 women), median age was 38 years, median CD4 + T-cell count was 322 cells/μL, median duration on ART was 18 months, and median (interquartile range) efavirenz concentration was 2.23 (1.66 to 4.10) μg/mL. On multivariable analyses (adjusting for age, sex, body mass index, and ART duration) doubling of efavirenz concentrations resulted in mean changes in mmol/L (95%CI) of: total cholesterol (0.40 [0.22 to 0.59]), LDL cholesterol (0.19 [0.04 to 0.30]), HDL cholesterol (0.14 [0.07 to 0.20]), triglycerides (0.17 [0.03 to 0.33]), fasting glucose (0.18 [0.03 to 0.33]), and 2-h glucose concentrations (0.33 [0.08 to 0.60]). Among 57 participants with CYP2B6 genotype data, associations between slow metabolizer genotypes and metabolic profiles were generally consistent with those for measured efavirenz concentrations.Higher plasma efavirenz concentrations are associated with higher plasma lipid and glucose concentrations. This may have implications for long-term cardiovascular complications of efavirenz-based ART, particularly among populations with high prevalence of CYP2B6 slow metabolizer genotypes. PMID:26765416

  1. Advanced solar concentrator: Executive summary

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The preliminary design of a point-focusing solar concentrator, consisting of a steerable space frame structure supporting a paraboloidal mirror glass reflector, is described. A mass production, operation, and maintenance cost assessment is presented. A conceptual evaluation of a modified concentrator design is included. The detailed design of one of the lightweight, structurally efficient reflective elements comprising the paraboloidal reflective surface is given.

  2. Optimal concentrations in transport systems

    PubMed Central

    Jensen, Kaare H.; Kim, Wonjung; Holbrook, N. Michele; Bush, John W. M.

    2013-01-01

    Many biological and man-made systems rely on transport systems for the distribution of material, for example matter and energy. Material transfer in these systems is determined by the flow rate and the concentration of material. While the most concentrated solutions offer the greatest potential in terms of material transfer, impedance typically increases with concentration, thus making them the most difficult to transport. We develop a general framework for describing systems for which impedance increases with concentration, and consider material flow in four different natural systems: blood flow in vertebrates, sugar transport in vascular plants and two modes of nectar drinking in birds and insects. The model provides a simple method for determining the optimum concentration copt in these systems. The model further suggests that the impedance at the optimum concentration μopt may be expressed in terms of the impedance of the pure (c = 0) carrier medium μ0 as μopt∼2αμ0, where the power α is prescribed by the specific flow constraints, for example constant pressure for blood flow (α = 1) or constant work rate for certain nectar-drinking insects (α = 6). Comparing the model predictions with experimental data from more than 100 animal and plant species, we find that the simple model rationalizes the observed concentrations and impedances. The model provides a universal framework for studying flows impeded by concentration, and yields insight into optimization in engineered systems, such as traffic flow. PMID:23594815

  3. Monolithic microfluidic concentrators and mixers

    DOEpatents

    Frechet, Jean M.; Svec, Frantisek; Yu, Cong; Rohr, Thomas

    2005-05-03

    Microfluidic devices comprising porous monolithic polymer for concentration, extraction or mixing of fluids. A method for in situ preparation of monolithic polymers by in situ initiated polymerization of polymer precursors within microchannels of a microfluidic device and their use for solid phase extraction (SPE), preconcentration, concentration and mixing.

  4. Process for concentrated biomass saccharification

    DOEpatents

    Hennessey, Susan M.; Seapan, Mayis; Elander, Richard T.; Tucker, Melvin P.

    2010-10-05

    Processes for saccharification of pretreated biomass to obtain high concentrations of fermentable sugars are provided. Specifically, a process was developed that uses a fed batch approach with particle size reduction to provide a high dry weight of biomass content enzymatic saccharification reaction, which produces a high sugars concentration hydrolysate, using a low cost reactor system.

  5. Space solar arrays and concentrators

    NASA Astrophysics Data System (ADS)

    Habraken, Serge; Defise, Jean-Marc; Collette, Jean-Paul; Rochus, Pierre; D'Odemont, Pierre-Alexis; Hogge, Michel

    2001-03-01

    This paper presents some research activities conducted at the Centre Spatial de Liege (CSL) in the field of space solar arrays and concentration. With the new generation of high efficiency solar cells, solar concentration brings new insights for future high power spacecrafts. A trade-off study is presented in this paper. Two different trough concentrators, and a linear Fresnel lens concentrator are compared to rigid arrays. Thermal and optical behaviors are included in the analysis. Several technical aspects are discussed: Off-pointing with concentrators induces collection loss and illumination non uniformity, reducing the PV efficiency. Concentrator deployment increases the mission risk. Reflective trough concentrators are attractive and already proven. Coating is made of VDA (Aluminum). A comprehensive analysis of PV conversion increase with protected silver is presented. Solar concentration increases the heat load on solar cells, while the conversion efficiency is significantly decreasing at warm temperatures. To conclude, this paper will point out the new trends and the key factors to be addressed for the next generation of solar generators.

  6. Spiral concentrators recover fine coal

    SciTech Connect

    Fiscor, S.

    2005-12-15

    Compound spirals offer better performance in a more efficient configuration. Prep plant operators in the US are increasingly opting to use spiral concentrators. They are easy to install, operate and maintain but their downfall is low capacity. The article describes spirals available from PrepTech/Multotec, Krebs Engineers and Roche MT. It reports on research on spiral concentrator technology. 1 ref., 4 figs.

  7. Inflatable Solar Thermal Concentrator Delivered

    NASA Technical Reports Server (NTRS)

    Tolbert, Carol M.

    1999-01-01

    Space-based solar thermal power systems are very appealing as a space power source because they generate power efficiently. However, solar thermal (dynamic) systems currently incorporate rigid concentrators that are relatively heavy and require significant packaging volume and robust deployment schemes. In many ways, these requirements make these systems less appealing than photovoltaic systems. As an alternative to solar thermal power systems with rigid concentrators, solar thermal power systems with thin film inflation-deployed concentrators have low cost, are lightweight, and are efficiently packaged and deployed. Not only are inflatable concentrators suitable for low Earth orbit and geosynchronous orbit applications, but they can be utilized in deep space missions to concentrate solar energy to high-efficiency solar cells.

  8. Incidence and predictive factors of first episode of spontaneous bacterial peritonitis in cirrhosis with ascites: relevance of ascitic fluid protein concentration.

    PubMed

    Llach, J; Rimola, A; Navasa, M; Ginès, P; Salmerón, J M; Ginès, A; Arroyo, V; Rodés, J

    1992-09-01

    To investigate the long-term probability of the appearance of the first episode of spontaneous bacterial peritonitis in cirrhosis with ascites and to identify predictors of this complication, we closely followed throughout their illness 127 patients consecutively admitted to our unit for the treatment of an episode of ascites without prior spontaneous bacterial peritonitis (follow-up period: 21 +/- 22 mo). Thirteen patients (10%) had the first spontaneous bacterial peritonitis episode during follow-up. The appearance probability of this complication is 11% at 1 yr and 15% at 3 yr. Thirty-three variables obtained at admission (including clinical data, standard liver and kidney function test results, ascitic fluid protein concentrations and hemodynamic parameters) were analyzed in relation to their value in predicting spontaneous bacterial peritonitis development. In univariate analysis (Kaplan-Meier curves) five variables reached statistical significance (p less than 0.05) as predictive factors for the development of the first spontaneous bacterial peritonitis episode. These five variables were poor nutritional status, increased serum bilirubin levels, increased serum AST levels, decreased prothrombin activity and reduced total protein concentration in ascitic fluid. When these five variables were introduced in a multivariate analysis, only the ascitic fluid protein concentration was found to correlate independently with spontaneous bacterial peritonitis development (p = 0.002). The probability of first spontaneous bacterial peritonitis after 3 yr of follow-up was 24% and 4% in patients with ascitic fluid protein content lower than 1 gm/dl and greater than or equal to 1 gm/dl, respectively.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1505916

  9. Cyanobacterial NADPH dehydrogenase complexes

    SciTech Connect

    Ogawa, Teruo; Mi, Hualing

    2007-07-01

    Cyanobacteria possess functionally distinct multiple NADPH dehydrogenase (NDH-1) complexes that are essential to CO2 uptake, photosystem-1 cyclic electron transport and respiration. The unique nature of cyanobacterial NDH-1 complexes is the presence of subunits involved in CO2 uptake. Other than CO2 uptake, chloroplastic NDH-1 complex has similar role as cyanobacterial NDH-1 complexes in photosystem-1 cyclic electron transport and respiration (chlororespiration). In this mini-review we focus on the structure and function of cyanobacterial NDH-1 complexes and their phylogeny. The function of chloroplastic NDH-1 complex and characteristics of plants defective in NDH-1 are also described forcomparison.

  10. Concentrating membrane proteins using ultrafiltration without concentrating detergents.

    PubMed

    Feroz, Hasin; Vandervelden, Craig; Ikwuagwu, Bon; Ferlez, Bryan; Baker, Carol S; Lugar, Daniel J; Grzelakowski, Mariusz; Golbeck, John H; Zydney, Andrew L; Kumar, Manish

    2016-10-01

    Membrane proteins (MPs) are of rapidly growing interest in the design of pharmaceutical products, novel sensors, and synthetic membranes. Ultrafiltration (UF) using commercially available centrifugal concentrators is typically employed for laboratory-scale concentration of low-yield MPs, but its use is accompanied by a concomitant increase in concentration of detergent micelles. We present a detailed analysis of the hydrodynamic processes that control detergent passage during ultrafiltration of MPs and propose methods to optimize detergent passage during protein concentration in larger-scale membrane processes. Experiments were conducted using nonionic detergents, octyl-β-D glucoside (OG), and decyl-β-D maltoside (DM) with the bacterial water channel protein, Aquaporin Z (AqpZ) and the light driven chloride pump, halorhodopsin (HR), respectively. The observed sieving coefficient (So ), a measure of detergent passage, was evaluated in both stirred cell and centrifugal systems. So for DM and OG increased with increasing filtrate flux and decreasing shear rates in the stirred cell, that is, with increasing concentration polarization (CP). Similar effects were observed during filtration of MP-detergent (MPD) micelles. However, lower transmission was observed in the centrifugal system for both detergent and MPD systems. This is attributed to free convection-induced shear and hence reduced CP along the membrane surface during centrifugal UF. Thus to concentrate MPs without retention of detergent, design of UF systems that promote CP is required. Biotechnol. Bioeng. 2016;113: 2122-2130. © 2016 Wiley Periodicals, Inc. PMID:27563851

  11. Optimal Concentrations in Transport Networks

    NASA Astrophysics Data System (ADS)

    Jensen, Kaare; Savage, Jessica; Kim, Wonjung; Bush, John; Holbrook, N. Michele

    2013-03-01

    Biological and man-made systems rely on effective transport networks for distribution of material and energy. Mass flow in these networks is determined by the flow rate and the concentration of material. While the most concentrated solution offers the greatest potential for mass flow, impedance grows with concentration and thus makes it the most difficult to transport. The concentration at which mass flow is optimal depends on specific physical and physiological properties of the system. We derive a simple model which is able to predict optimal concentrations observed in blood flows, sugar transport in plants, and nectar feeding animals. Our model predicts that the viscosity at the optimal concentration μopt =2nμ0 is an integer power of two times the viscosity of the pure carrier medium μ0. We show how the observed powers 1 <= n <= 6 agree well with theory and discuss how n depends on biological constraints imposed on the transport process. The model provides a universal framework for studying flows impeded by concentration and provides hints of how to optimize engineered flow systems, such as congestion in traffic flows.

  12. Solar Concentrator Advanced Development Program

    NASA Technical Reports Server (NTRS)

    Knasel, Don; Ehresman, Derik

    1989-01-01

    The Solar Concentrator Advanced Development Project has successfully designed, fabricated, and tested a full scale prototypical solar dynamic concentrator for space station applications. A Truss Hexagonal Panel reflector was selected as a viable solar concentrator concept to be used for space station applications. This concentrator utilizes a modular design approach and is flexible in attainable flux profiles and assembly techniques. The detailed design of the concentrator, which included structural, thermal and optical analysis, identified the feasibility of the design and specific technologies that were required to fabricate it. The needed surface accuracy of the reflectors surface was found to be very tight, within 5 mrad RMS slope error, and results in very close tolerances for fabrication. To meet the design requirements, a modular structure composed of hexagonal panels was used. The panels, made up of graphite epoxy box beams provided the strength, stiffness and dimensional stability needed. All initial project requirements were met or exceeded by hardware demonstration. Initial testing of structural repeatability of a seven panel portion of the concentrator was followed by assembly and testing of the full nineteen panel structure. The testing, which consisted of theodolite and optical measurements over an assembly-disassembly-reassembly cycle, demonstrated that the concentrator maintained the as-built contour and optical characteristics. The facet development effort within the project, which included developing the vapor deposited reflective facet, produced a viable design with demonstrated optical characteristics that are within the project goals.

  13. Serum cholesterol concentrations in parasuicide.

    PubMed Central

    Gallerani, M.; Manfredini, R.; Caracciolo, S.; Scapoli, C.; Molinari, S.; Fersini, C.

    1995-01-01

    OBJECTIVE--To evaluate whether people who have committed parasuicide have low serum cholesterol concentrations. DESIGN--Results of blood tests in subjects admitted to hospital for parasuicide compared with those of a control group of non-suicidal subjects; comparison in subgroup of parasuicide subjects of two sets of blood test results (one set from admission for parasuicide and the other from admission for some other illness). SETTING--General hospital, Ferrara, Italy. SUBJECTS--331 parasuicide subjects aged 44 (SD 21) years (109 with two sets of blood test results) and 331 controls. MAIN OUTCOME MEASURES--Serum cholesterol concentrations and possible association with parasuicide, considering sex, violence of method of parasuicide, and underlying psychiatric disorder. RESULTS--Lower serum cholesterol concentrations (4.96 (SD 1.16) mmol/l) were found in the parasuicide subjects than in the controls (5.43 (1.30); P < 0.001), regardless of sex and degree of violence of parasuicide method. Both men and women with two sets of blood test results had lower cholesterol concentrations after parasuicide. Linear regression analysis showed that the difference in cholesterol concentrations was significantly related to the length of time between the taking of the two sets of blood samples. CONCLUSION--The study showed low cholesterol concentrations after parasuicide. This finding agrees with previous studies, which suggest an association between low cholesterol concentration and suicide. PMID:7795448

  14. Altering prolactin concentrations in sows.

    PubMed

    Farmer, C

    2016-07-01

    Prolactin has a multiplicity of actions, but it is of particular importance in gestating and lactating animals. In sows, it is involved in the control of mammary development and also holds essential roles in the lactogenic and galactopoietic processes. Furthermore, low circulating concentrations of prolactin are associated with the agalactia syndrome. The crucial role of prolactin makes it important to understand the various factors that can alter its secretion. Regulation of prolactin secretion is largely under the negative control of dopamine, and dopamine agonists consistently decrease prolactin concentrations in sows. On the other hand, injections of dopamine antagonists can enhance circulating prolactin concentrations. Besides pharmacologic agents, many other factors can also alter prolactin concentrations in sows. The use of Chinese-derived breeds, for instance, leads to increased prolactin concentrations in lactating sows compared with standard European white breeds. Numerous husbandry and feeding practices also have a potential impact on prolactin concentrations in sows. Factors, such as provision of nest-building material prepartum, housing at farrowing, high ambient temperature, stress, transient weaning, exogenous thyrotropin-releasing factor, exogenous growth hormone-releasing factor, nursing frequency, prolonged photoperiod, fasting, increased protein and/or energy intake, altered energy sources, feeding high-fiber diets, sorghum ergot or plant extracts, were all studied with respect to their prolactinemic properties. Although some of these practices do indeed affect circulating prolactin concentrations, none leads to changes as drastic as those brought about by dopamine agonists or antagonists. It appears that the numerous factors regulating prolactin concentrations in sows are still not fully elucidated, and that studies to develop novel applicable ways of increasing prolactin concentrations in sows are warranted. PMID:27345313

  15. Qualification testing of photovoltaic concentrators

    NASA Astrophysics Data System (ADS)

    Richards, E. H.; Barlow, R. S.

    Sandia has developed a revised set of specifications for qualification testing of passively-cooled photovoltaic concentrator modules. The purpose of the tests is to screen new concentrator designs and new production runs for susceptibility to known failure mechanisms; concentrator hardware must be qualified prior to array-level installation at Sandia's Photovoltaic Advanced System Test Facility (PASTF). Tests for cell assemblies and receiver sections, as well as for complete modules, are specified. They include ultraviolet radiation testing of materials, characterization of electrical performance checks to assure safety and structural integrity of modules, and accelerated environmental aging or cycling.

  16. Tank waste concentration mechanism study

    SciTech Connect

    Pan, L.C.; Johnson, L.J.

    1994-09-01

    This study determines whether the existing 242-A Evaporator should continue to be used to concentrate the Hanford Site radioactive liquid tank wastes or be replaced by an alternative waste concentration process. Using the same philosophy, the study also determines what the waste concentration mechanism should be for the future TWRS program. Excess water from liquid DST waste should be removed to reduce the volume of waste feed for pretreatment, immobilization, and to free up storage capacity in existing tanks to support interim stabilization of SSTS, terminal cleanout of excess facilities, and other site remediation activities.

  17. Shear Banding of Complex Fluids

    NASA Astrophysics Data System (ADS)

    Divoux, Thibaut; Fardin, Marc A.; Manneville, Sebastien; Lerouge, Sandra

    2016-01-01

    Even in simple geometries, many complex fluids display nontrivial flow fields, with regions where shear is concentrated. The possibility for such shear banding has been known for several decades, but in recent years, we have seen an upsurge in studies offering an ever-more precise understanding of the phenomenon. The development of new techniques to probe the flow on multiple scales with increasing spatial and temporal resolution has opened the possibility for a synthesis of the many phenomena that could only have been thought of separately before. In this review, we bring together recent research on shear banding in polymeric and soft glassy materials and highlight their similarities and disparities.

  18. Doxorubicin Lipid Complex Injection

    MedlinePlus

    Doxorubicin lipid complex is used to treat ovarian cancer that has not improved or that has worsened after treatment with other medications. Doxorubicin lipid complex is also used to treat Kaposi's sarcoma ( ...

  19. Daunorubicin Lipid Complex Injection

    MedlinePlus

    Daunorubicin lipid complex is used to treat advanced Kaposi's sarcoma (a type of cancer that causes abnormal tissue to ... body) related to acquired immunodeficiency syndrome (AIDS). Daunorubicin lipid complex is in a class of medications called ...

  20. Vincristine Lipid Complex Injection

    MedlinePlus

    Vincristine lipid complex is used to treat a certain type of acute lymphoblastic leukemia (ALL; a type of cancer ... least two different treatments with other medications. Vincristine lipid complex is in a class of medications called ...

  1. Daunorubicin Lipid Complex Injection

    MedlinePlus

    Daunorubicin lipid complex is used to treat advanced Kaposi's sarcoma (a type of cancer that causes abnormal tissue to grow on ... related to acquired immunodeficiency syndrome (AIDS). Daunorubicin lipid complex is in a class of medications called anthracyclines. ...

  2. Cytarabine Lipid Complex Injection

    MedlinePlus

    Cytarabine lipid complex is used to treat lymphomatous meningitis (a type of cancer in the covering of the spinal cord and brain). Cytarabine lipid complex is in a class of medications called antimetabolites. ...

  3. Irinotecan Lipid Complex Injection

    MedlinePlus

    Irinotecan lipid complex is used in combination with other medications to treat pancreatic cancer that has spread to other parts of ... after treatment with other chemotherapy medications. Irinotecan lipid complex is in a class of antineoplastic medications called ...

  4. Complex regional pain syndrome

    MedlinePlus

    Complex regional pain syndrome (CRPS) is a chronic pain condition that can affect any area of the ... Bailey A, Audette JF. Complex regional pain syndrome. In: Frontera ... of Physical Medicine and Rehabilitation. 2nd ed. Philadelphia, ...

  5. Doxorubicin Lipid Complex Injection

    MedlinePlus

    Doxorubicin lipid complex is used to treat ovarian cancer that has not improved or that has worsened after treatment with other medications. Doxorubicin lipid complex is also used to treat Kaposi's sarcoma (a ...

  6. Vincristine Lipid Complex Injection

    MedlinePlus

    Vincristine lipid complex is used to treat a certain type of acute lymphoblastic leukemia (ALL; a type of cancer of the ... two different treatments with other medications. Vincristine lipid complex is in a class of medications called vinca ...

  7. Irinotecan Lipid Complex Injection

    MedlinePlus

    Irinotecan lipid complex is used in combination with other medications to treat pancreatic cancer that has spread ... has worsened after treatment with other chemotherapy medications. Irinotecan lipid complex is in a class of antineoplastic ...

  8. Oligocyclopentadienyl transition metal complexes

    SciTech Connect

    de Azevedo, Cristina G.; Vollhardt, K. Peter C.

    2002-01-18

    Synthesis, characterization, and reactivity studies of oligocyclopentadienyl transition metal complexes, namely those of fulvalene, tercyclopentadienyl, quatercyclopentadienyl, and pentacyclopentadienyl(cyclopentadienyl) are the subject of this account. Thermal-, photo-, and redox chemistries of homo- and heteropolynuclear complexes are described.

  9. Complex-I-ty in aging

    PubMed Central

    Stork, Devon A.

    2016-01-01

    The role of mitochondrial complex I in aging has been studied in both C. elegans and Drosophila, where RNAi knock down of specific complex I subunits has been shown to extend lifespan. More recently, studies in Drosophila have shown that an increase in mitochondrial activity, including complex I-like activity, can also slow aging. In this review, we discuss this apparent paradox. Improved maintenance of mitochondrial activity, mitochondrial homeostasis, may be responsible for lifespan extension in both cases. Decreased electron transport chain activity caused by reducing complex I subunit expression prompts an increase in stress response signaling that leads to enhanced mitochondrial homeostasis during aging. Increased complex I activity, as well as mitochondrial biogenesis, is expected to both directly counteract the decline in mitochondrial health that occurs during aging and may also increase cellular NAD+ levels, which have been linked to mitochondrial homeostatic mechanisms through activation of sirtuins. We suggest that manipulations that increase or decrease complex I activity both converge on improved mitochondrial homeostasis during aging, resulting in prolonged lifespan. PMID:24961226

  10. Meteorite concentration mechanisms in Antarctica

    NASA Technical Reports Server (NTRS)

    Annexstad, J. O.

    1986-01-01

    The location of most Antarctic meteorite finds is on stagnant, highly ablative surfaces known as blue ice. The role of blue ice as transporter, concentrator, and preserver of specimens from the time of fall until find is discussed.

  11. conindex: Estimation of concentration indices

    PubMed Central

    O'Donnell, Owen; O'Neill, Stephen; Van Ourti, Tom; Walsh, Brendan

    2016-01-01

    Concentration indices are frequently used to measure inequality in one variable over the distribution of another. Most commonly, they are applied to the measurement of socioeconomic-related inequality in health. We introduce a user-written Stata command conindex which provides point estimates and standard errors of a range of concentration indices. The command also graphs concentration curves (and Lorenz curves) and performs statistical inference for the comparison of inequality between groups. The article offers an accessible introduction to the various concentration indices that have been proposed to suit different measurement scales and ethical responses to inequality. The command’s capabilities and syntax are demonstrated through analysis of wealth-related inequality in health and healthcare in Cambodia. PMID:27053927

  12. Optimal concentrations in nectar feeding

    PubMed Central

    Kim, Wonjung; Gilet, Tristan; Bush, John W. M.

    2011-01-01

    Nectar drinkers must feed quickly and efficiently due to the threat of predation. While the sweetest nectar offers the greatest energetic rewards, the sharp increase of viscosity with sugar concentration makes it the most difficult to transport. We here demonstrate that the sugar concentration that optimizes energy transport depends exclusively on the drinking technique employed. We identify three nectar drinking techniques: active suction, capillary suction, and viscous dipping. For each, we deduce the dependence of the volume intake rate on the nectar viscosity and thus infer an optimal sugar concentration consistent with laboratory measurements. Our results provide the first rationale for why suction feeders typically pollinate flowers with lower sugar concentration nectar than their counterparts that use viscous dipping. PMID:21949358

  13. Thermodynamic efficiency of solar concentrators.

    PubMed

    Shatz, Narkis; Bortz, John; Winston, Roland

    2010-04-26

    The optical thermodynamic efficiency is a comprehensive metric that takes into account all loss mechanisms associated with transferring flux from the source to the target phase space, which may include losses due to inadequate design, non-ideal materials, fabrication errors, and less than maximal concentration. We discuss consequences of Fermat's principle of geometrical optics and review étendue dilution and optical loss mechanisms associated with nonimaging concentrators. We develop an expression for the optical thermodynamic efficiency which combines the first and second laws of thermodynamics. As such, this metric is a gold standard for evaluating the performance of nonimaging concentrators. We provide examples illustrating the use of this new metric for concentrating photovoltaic systems for solar power applications, and in particular show how skewness mismatch limits the attainable optical thermodynamic efficiency. PMID:20607882

  14. Thermodynamic efficiency of solar concentrators.

    PubMed

    Shatz, Narkis; Bortz, John; Winston, Roland

    2010-04-26

    The optical thermodynamic efficiency is a comprehensive metric that takes into account all loss mechanisms associated with transferring flux from the source to the target phase space, which may include losses due to inadequate design, non-ideal materials, fabrication errors, and less than maximal concentration. We discuss consequences of Fermat's principle of geometrical optics and review étendue dilution and optical loss mechanisms associated with nonimaging concentrators. We develop an expression for the optical thermodynamic efficiency which combines the first and second laws of thermodynamics. As such, this metric is a gold standard for evaluating the performance of nonimaging concentrators. We provide examples illustrating the use of this new metric for concentrating photovoltaic systems for solar power applications, and in particular show how skewness mismatch limits the attainable optical thermodynamic efficiency. PMID:20588573

  15. Thin film concentrator panel development

    NASA Astrophysics Data System (ADS)

    Zimmerman, D. K.

    1982-07-01

    The development and testing of a rigid panel concept that utilizes a thin film reflective surface for application to a low-cost point-focusing solar concentrator is discussed. It is shown that a thin film reflective surface is acceptable for use on solar concentrators, including 1500 F applications. Additionally, it is shown that a formed steel sheet substrate is a good choice for concentrator panels. The panel has good optical properties, acceptable forming tolerances, environmentally resistant substrate and stiffeners, and adaptability to low to mass production rates. Computer simulations of the concentrator optics were run using the selected reflector panel design. Experimentally determined values for reflector surface specularity and reflectivity along with dimensional data were used in the analysis. The simulations provided intercept factor and net energy into the aperture as a function of aperture size for different surface errors and pointing errors. Point source and Sun source optical tests were also performed.

  16. Concentrating Solar Power (Fact Sheet)

    SciTech Connect

    DOE Solar Energy Technologies Program

    2011-10-13

    Concentrating Solar Power (CSP) offers a utility-scale, firm, dispatchable renewable energy option that can help meet the nation's goal of making solar energy cost competitive with other energy sources by the end of the decade.

  17. Intrinsic and observed concentration-mass relation

    NASA Astrophysics Data System (ADS)

    Rasia, Elena; Meneghetti, M.; Borgani, S.; Ettori, S.

    2012-05-01

    The concentration-mass relation represents a valuable tool to constrain cosmological parameters such as matter density and \\sigma_8. In the last few years, samples of optical and X-ray data led to the conclusion that the observed relation has a higher normalization and slope than predicted by dark-matter only simulations. In this work, we explore whether this disagreement is real and, if so, why it exists. To this purpose, we consider 30 clusters simulated by progressively increasing the simulation complexity: (i) dark-matter only, (ii) non-radiative hydrodynamics, (iii) adding cooling, star-formation and feedback by Supernovae, (iv) further adding feedback by AGN. We produced X-ray and optical synthetic catalogues to derive the concentration-mass relation following an observational approach. We find that even if cooling has the effect of steepening the concentration-mass relation with respect to the DM-only simulations, the introduction of AGN makes this difference small (5-10%). A larger variation is expected when reducing the radial range over which density profiles are fitted to a NFW profile. In particular if the external radius is about half $R_{500}$ the slope can double its value. Therefore, observations, suffering from background contamination, are more inclined to detect a steeper c-M relations. Finally, the strong lensing analysis of the synthetic catalogues shows a bias leading to an over-estimate the concentration of small objects. We acknowledge financial contribution from contracts ASI-INAF I/023/05/0, ASI-INAF I/088/06/0, PRIN-INAF-2009 Grant "Towards an Italian Network for Computational Cosmology", INFN PD51, the Michigan Society of Fellow, and the Michigan Center for Theoretical Physics.

  18. Concentrated insulins: the new basal insulins

    PubMed Central

    Lamos, Elizabeth M; Younk, Lisa M; Davis, Stephen N

    2016-01-01

    Introduction Insulin therapy plays a critical role in the treatment of type 1 and type 2 diabetes mellitus. However, there is still a need to find basal insulins with 24-hour coverage and reduced risk of hypoglycemia. Additionally, with increasing obesity and insulin resistance, the ability to provide clinically necessary high doses of insulin at low volume is also needed. Areas covered This review highlights the published reports of the pharmacokinetic (PK) and glucodynamic properties of concentrated insulins: Humulin-R U500, insulin degludec U200, and insulin glargine U300, describes the clinical efficacy, risk of hypoglycemic, and metabolic changes observed, and finally, discusses observations about the complexity of introducing a new generation of concentrated insulins to the therapeutic market. Conclusion Humulin-R U500 has a similar onset but longer duration of action compared with U100 regular insulin. Insulin glargine U300 has differential PK/pharmacodynamic effects when compared with insulin glargine U100. In noninferiority studies, glycemic control with degludec U200 and glargine U300 is similar to insulin glargine U100 and nocturnal hypoglycemia is reduced. Concentrated formulations appear to behave as separate molecular entities when compared with earlier U100 insulin analog compounds. In the review of available published data, newer concentrated basal insulins may offer an advantage in terms of reduced intraindividual variability as well as reducing the injection burden in individuals requiring high-dose and large volume insulin therapy. Understanding the PK and pharmacodynamic properties of this new generation of insulins is critical to safe dosing, dispensing, and administration. PMID:27022271

  19. Teorell instability in concentration polarization.

    PubMed

    Abu-Rjal, Ramadan; Prigozhin, Leonid; Rubinstein, Isaak; Zaltzman, Boris

    2015-08-01

    We investigate the development of electro-osmotic (Teorell) oscillations at a weakly charged microporous membrane without a preimposed transmembrane electrolyte concentration drop. This drop, necessary for the occurrence of oscillations, develops spontaneously as a result of concentration polarization in the solution layers adjacent to the membrane. A three-layer model comprising a membrane flanked by two diffusion layers is proposed and analyzed for galvano- and potentiostatic regimes of operation. PMID:26382404

  20. Teorell instability in concentration polarization

    NASA Astrophysics Data System (ADS)

    Abu-Rjal, Ramadan; Prigozhin, Leonid; Rubinstein, Isaak; Zaltzman, Boris

    2015-08-01

    We investigate the development of electro-osmotic (Teorell) oscillations at a weakly charged microporous membrane without a preimposed transmembrane electrolyte concentration drop. This drop, necessary for the occurrence of oscillations, develops spontaneously as a result of concentration polarization in the solution layers adjacent to the membrane. A three-layer model comprising a membrane flanked by two diffusion layers is proposed and analyzed for galvano- and potentiostatic regimes of operation.

  1. Optical monitoring of glucose concentration

    NASA Astrophysics Data System (ADS)

    Ross, I. N.; Mbanu, A.

    1985-02-01

    A device for the monitoring of blood glucose levels is investigated. It measures the sugar concentration using the effect of the glucose on the optical refractive index. Light is transmitted along an optical fibre, and, as most of the internal rays are incident at the fibre surface at an angle less than the critical angle, the refractive index of the surrounding liquid can be calculated. The device can measure glucose concentrations with a sensitivity of better than 0.1%.

  2. Immunoisolation of Protein Complexes from Xenopus

    PubMed Central

    Conlon, Frank L.; Miteva, Yana; Kaltenbrun, Erin; Waldron, Lauren; Greco, Todd M.; Cristea, Ileana M.

    2013-01-01

    The immunoaffinity isolation of protein complexes is an essential technique for the purification and concentration of protein complexes from cells and tissues. In this chapter we present the methodologies for the purification of proteins and protein complexes from Xenopus laev is and Xenopus tropical is. Specific to this protocol are the techniques for the cryolysis of Xenopus cells and tissues, a procedure that limits contamination from yolk proteins while preserving endogenous protein complexes, the methodologies for immunoaffinity purification of proteins using magnetic beads, and the protocols for western blot analysis. In addition, the procedures in this chapter can be extended to use with proteomic analysis of protein complexes as presented in the following chapter. PMID:22956099

  3. The Electrostatic Screening Length in Concentrated Electrolytes Increases with Concentration.

    PubMed

    Smith, Alexander M; Lee, Alpha A; Perkin, Susan

    2016-06-16

    According to classical electrolyte theories interactions in dilute (low ion density) electrolytes decay exponentially with distance, with the Debye screening length the characteristic length scale. This decay length decreases monotonically with increasing ion concentration due to effective screening of charges over short distances. Thus, within the Debye model no long-range forces are expected in concentrated electrolytes. Here we reveal, using experimental detection of the interaction between two planar charged surfaces across a wide range of electrolytes, that beyond the dilute (Debye-Hückel) regime the screening length increases with increasing concentration. The screening lengths for all electrolytes studied-including aqueous NaCl solutions, ionic liquids diluted with propylene carbonate, and pure ionic liquids-collapse onto a single curve when scaled by the dielectric constant. This nonmonotonic variation of the screening length with concentration, and its generality across ionic liquids and aqueous salt solutions, demonstrates an important characteristic of concentrated electrolytes of substantial relevance from biology to energy storage. PMID:27216986

  4. Novel measures based on the Kolmogorov complexity for use in complex system behavior studies and time series analysis

    NASA Astrophysics Data System (ADS)

    Mihailović, Dragutin T.; Mimić, Gordan; Nikolić-Djorić, Emilija; Arsenić, Ilija

    2015-01-01

    We propose novel metrics based on the Kolmogorov complexity for use in complex system behavior studies and time series analysis. We consider the origins of the Kolmogorov complexity and discuss its physical meaning. To get better insights into the nature of complex systems and time series analysis we introduce three novel measures based on the Kolmogorov complexity: (i) the Kolmogorov complexity spectrum, (ii) the Kolmogorov complexity spectrum highest value and (iii) the overall Kolmogorov complexity. The characteristics of these measures have been tested using a generalized logistic equation. Finally, the proposed measures have been applied to different time series originating from: a model output (the biochemical substance exchange in a multi-cell system), four different geophysical phenomena (dynamics of: river flow, long term precipitation, indoor 222Rn concentration and UV radiation dose) and the economy (stock price dynamics). The results obtained offer deeper insights into the complexity of system dynamics and time series analysis with the proposed complexity measures.

  5. Design and development of a high-concentration photovoltaic concentrator

    SciTech Connect

    Hodge, R C

    1982-04-01

    The design and development of a high concentration photovoltaic concentrator module is discussed. The design concept described herein incorporates a curved groove domed Fresnel lens, a high concentration etched multiple vertical junction (EMVJ) solar cell and a passively cooled direct-bonded copper cell mount all packaged in a plastic module. Two seven inch diameter 1200x domed Fresnel lenses were fabricated using single point diamond turning technology. Testing at both GE and Sandia confirmed optical transmission efficiencies of over 83%. Samples of the latest available EMVJ cells were mounted and installed, with a domed Fresnel lens, into a prototype module. Subsequent testing demonstrated net lens-cell efficiencies of 10 to 13%. As a result of this program, salient conclusions have been formulated as to this technology.

  6. Complex history of the discovery and characterization of congenital factor X deficiency.

    PubMed

    Girolami, Antonio; Cosi, Elisabetta; Sambado, Luisa; Girolami, Bruno; Randi, Maria Luigia

    2015-06-01

    Factor X (FX) plays a pivotal role in blood coagulation. FX represents the point where all coagulation systems converge and, once activated, it converts prothrombin into thrombin. The discovery and definition of FX are based on the description between 1956 and 1957 about three patients and their families with a peculiar defect later demonstrated to be almost identical. These patients were an American (Mr. Stuart), a British (Ms. Prower), and a Swiss with Italian background (infant Delia B). We stated "almost identical" because immunological and molecular biology studies subsequently revealed that even though the basic clotting defect was identical, the FX protein level and the mutation were different in each case. Mr. Stuart had no FX protein in his plasma and the mutation was Val298Met (homozygote). Ms. Prower instead had a normal level of FX protein and the mutation was Arg287Trp + Asp282Asn (compound heterozygote). Unfortunately, the status of the Swiss patient in this regard is not known. Subsequent studies described a few major variants (FX Friuli, FX Melbourne, FX Padua, and other similar patients), which showed peculiar activation patterns (FX Friuli had a normal Russell viper venom clotting time; FX Melbourne was defective only in the intrinsic coagulation system; FX Padua, on the contrary, was defective only in the extrinsic coagulation system). All these studies have informed on the great heterogeneity and complexity of the FX defect. The story of the discovery and classification of FX deficiency has contributed considerably to our understanding of blood coagulation. The three original families and the families of the major variants, together with the researchers that discovered them, should be remembered with deep respect and gratitude. PMID:25875733

  7. Palladium (II) Hydrazopyrazolone Complexes

    NASA Astrophysics Data System (ADS)

    El-Maraghy, Salah B.; Salib, K. A.; Stefan, Shaker L.

    1989-12-01

    Palladium (II) complexes with 1-pheny1-3-methy1-4-(arylhydrazo)-5- pyrazolone dyes were studied spectrophotometrically. Pd (II) forms 1:1 and 1:2 complexes with the ligands by the replacement of their phenolic and hydrazo protons. The ligands behave as tridentate in the 1:1 complex and as bidentate in the 1:2 complex. The sability constants of these complexes are dependent on the type of substituents in the benzene ring of the arylazo moiety.

  8. Heuristic dynamic complexity coding

    NASA Astrophysics Data System (ADS)

    Škorupa, Jozef; Slowack, Jürgen; Mys, Stefaan; Lambert, Peter; Van de Walle, Rik

    2008-04-01

    Distributed video coding is a new video coding paradigm that shifts the computational intensive motion estimation from encoder to decoder. This results in a lightweight encoder and a complex decoder, as opposed to the predictive video coding scheme (e.g., MPEG-X and H.26X) with a complex encoder and a lightweight decoder. Both schemas, however, do not have the ability to adapt to varying complexity constraints imposed by encoder and decoder, which is an essential ability for applications targeting a wide range of devices with different complexity constraints or applications with temporary variable complexity constraints. Moreover, the effect of complexity adaptation on the overall compression performance is of great importance and has not yet been investigated. To address this need, we have developed a video coding system with the possibility to adapt itself to complexity constraints by dynamically sharing the motion estimation computations between both components. On this system we have studied the effect of the complexity distribution on the compression performance. This paper describes how motion estimation can be shared using heuristic dynamic complexity and how distribution of complexity affects the overall compression performance of the system. The results show that the complexity can indeed be shared between encoder and decoder in an efficient way at acceptable rate-distortion performance.

  9. Environmental Contaminants in Wildlife: Interpreting Tissue Concentrations

    USGS Publications Warehouse

    1996-01-01

    Covers the complex issue of how to evaluate contaminants in wildlife. This comprehensive resource deals with the question: 'How much of a chemical in the tissues of an animal is harmful?' Features: Authoritative and sound advice is provided on many environmental contaminants, including what the contaminants are and how to interpret the data on them. Each chapter includes a review of the literature on a specific chemical, followed by a clear technical summary that provides research guidance. Direction is given on how to interpret data that are sometimes conflicting or insufficient. Data are presented in easy to use tables. Primary attention is given to toxic concentrations of contaminants such as organochlorine pesticides, PCBs, dioxins, PAHs, metals, and fluorides.

  10. Concentrating Engines and the Kidney

    PubMed Central

    Stephenson, John L.

    1973-01-01

    Mass balance relations, valid for any counterflow system, are derived and applied to a central core model of the renal medulla, in which descending Henle's limbs (DHL), ascending Henle's limbs (AHL), and collecting ducts (CD) exchange with a central vascular core (VC) formed by vasa recta loops, assumed so highly permeable that the core functions as a single tube open at the cortical end, closed at the papillary. Solute supplied to the VC primarily by the water impermeable AHL may either enter the DHL to be recycled or remain in the core to extract water by osmosis from DHL and CD. If concentrations in core and descending flows are nearly equal, then for all degrees of recycling the ratio of entering DHL concentration to loop concentration is given by r = 1/[1 - fT(1 - fU)], where fT is the fractional net solute transport out of AHL and fU is the ratio of CD flow to the sum of CD and AHL flows. Differential equations for a single solute are derived for core and AHL concentrations. Explicit analytic solutions are given for solute transport out of the AHL governed by Michaelis-Menten kinetics. Finally the energy requirements for concentration are analyzed. PMID:4714446

  11. Progress in photovoltaic concentrator research

    SciTech Connect

    Arvizu, D.E.

    1987-01-01

    This paper reviews the recent progress in photovoltaic concentrator research. In the past 18 months, several exciting new developments have been reported. Record efficiency concentrator silicon cells have been reported at Stanford University, with 28% efficient high resistivity cells, and at the University of New South Wales, with near 25% efficient low resistivity cells. Both groups also report record 22% one-sun efficiencies for these cells. Compound semiconductor cells have also made advances. Research on multijunction devices has led to a mechanically stacked concentrator cell with near 27% efficiency. Module improvements in commercial designs have taken the form of reduced cost and better component reliability. In addition, current research emphasis is on the development of new prototype modules that use the recent laboratory cell advances. Array efforts have centered around improving the tracking and control subsystems in accuracy, durability, and cost. Today, concentrator systems in high insolation areas are being offered at prices near $4/W/sub p/ ac for large MW sizes and at prices below those of flat plate systems ($8/W/sub p/) in hundred kW sizes. This paper will review these achievements and discuss the potential for concentrator technology to become a viable cost-effective bulk electrical power option.

  12. Progress in photovoltiac concentrator research

    SciTech Connect

    Arvizu, D.E.

    1986-10-01

    This paper reviews the recent progress in photovoltaic concentrator research. New record efficiency concentrator silicon cells have been reported at Stanford University, with 28% efficient high resistivity cells, and at the University of New South Wales, with near 25% efficient low resistivity cells. Both also report record 22% one-sun efficiencies. Compound semiconductor cells have also made advances. Research on multijunction devices has led to a mechanically stacked concentrator cell with near 27% efficiency. Module improvements have taken the form of reduced cost and better component reliability. In addition, a research emphasis is the development of new prototype modules that use the new laboratory cell advances. Array efforts have centered around improving the tracking and control subsystems in accuracy, durability, and cost. Today, concentrator systems in high insolation areas are being offered at prices near $4/W/sub p/ ac for large MW sizes and at prices below those of flat plate systems ($8/W/sub p/) in hundred kW sizes. This paper will review these achievements and discuss the potential for concentrator technology to become a viable cost-effective bulk electrical power option.

  13. Initial test bed concentrator characterization

    NASA Technical Reports Server (NTRS)

    Starkey, D. J.

    1980-01-01

    The operational characteristics and the mirror alignment technique of the test bed concentrator control system are highlighted. The final design of the TBC control system provided one axis of fast slew capability so that either the Sun acquisition or emergency off-Sun mode could be obtained in a minimum time. The procedure for getting on and off Sun is to run the elevation axis up to the approximate elevation of the Sun for the particular time of acquisition and then slew the concentrator on Sun in azimuth. The automatic Sun-acquisition system is controlled by two Sun sensors, one for each axis; each has a 2deg acquisition cone angle within which the concentrators are programmed to point. The mirror alignment technique chosen utilized a semi-distant incandescent light source which produced a reflected image on the focal point target. The concentrator was boresighted to the light by moving the concentrator while sighting along the cross hairs and through the apertures in the disks to the light source resulting in a maximum point error of 0.11 deg. Test plans to install a solar flux mapper to characterize the solar spot and to measure the size, shape, and intensity of the Sun's image are outlined.

  14. [Gastrointestinal bleeding in cardiological patients].

    PubMed

    Braun, G; Messmann, H

    2013-11-01

    Oral anticoagulation and antiplatelet therapy are risk factors for gastrointestinal (GI) bleeding. GI bleeding-especially lower GI bleeding-seems to be associated with a poorer outcome. With the introduction of dabigatrane and rivaroxaban, difficulties in the management of bleeding complications arose. Thus, the goal of the authors was to establish a standard operating procedure (SOP) for the treatment of severe GI bleeding associated with rivaroxaban, dabigatrane, and antiplatelet therapy. Bleeding complications during phenprocoumon treatment should be treated with prothrombin complex concentrates and vitamin K1. Dabigatrane elimination is highly dependent to the renal function. The measurement of drug concentrations of dabigatrane and rivaroxaban is useful to indicate an increased risk of bleeding complications. Severe bleeding associated with dabigatrane or rivaroxaban therapy should trigger prothrombin complex therapy, whereby in cases with severe bleeding associated with antiplatelet therapy platelet transfusion should be initiated. Low-dose aspirin should be continued after 24 h. PMID:24150711

  15. Combined processing of lead concentrates

    NASA Astrophysics Data System (ADS)

    Kubasov, V. L.; Paretskii, V. M.; Sidorin, G. N.; Travkin, V. F.

    2013-06-01

    A combined scheme of processing of lead concentrates with the production of pure metallic lead and the important components containing in these concentrates is considered. This scheme includes sulfating roasting of the lead concentrates and two-stage leaching of the formed cinder with the formation of a sulfate solution and lead sulfate. When transformed into a carbonate form, lead sulfate is used for the production of pure metallic lead. Silver, indium, copper, cadmium, nickel, cobalt, and other important components are separately extracted from a solution. At the last stage, zinc is extracted by either extraction followed by electrolytic extraction of a metal or the return of the forming solution of sulfuric acid to cinder leaching.

  16. Autonomous pump against concentration gradient

    NASA Astrophysics Data System (ADS)

    Xu, Zhi-Cheng; Zheng, Dong-Qin; Ai, Bao-Quan; Zhong, Wei-Rong

    2016-03-01

    Using non-equilibrium molecular dynamics and Monte Carlo methods, we have studied the molecular transport in asymmetric nanochannels. The efficiency of the molecular pump depends on the angle and apertures of the asymmetric channel, the environmental temperature and average concentration of the particles. The pumping effect can be explained as the competition between the molecular force field and the thermal disturbance. Our results provide a green approach for pumping fluid particles against the concentration gradient through asymmetric nanoscale thin films without any external forces. It indicates that pumping vacuum can be a spontaneous process.

  17. Measuring Hydrogen Concentrations in Metals

    NASA Technical Reports Server (NTRS)

    Danford, M. D.

    1985-01-01

    Commercial corrosion-measurement system adapted to electrochemical determination of hydrogen concentrations in metals. New technique based on diffusion of hydrogen through foil specimen of metal. In sample holder, hydrogen produced on one side of foil, either by corrosion reaction or by cathodic current. Hydrogen diffused through foil removed on other side by constant anode potential, which leads to oxidation of hydrogen to water. Anode current is measure of concentration of hydrogen diffusing through foil. System used to study hydrogen uptake, hydrogen elimination by baking, effect of heat treatment, and effect of electroplating on high-strength steels.

  18. Autonomous pump against concentration gradient

    PubMed Central

    Xu, Zhi-cheng; Zheng, Dong-qin; Ai, Bao-quan; Zhong, Wei-rong

    2016-01-01

    Using non-equilibrium molecular dynamics and Monte Carlo methods, we have studied the molecular transport in asymmetric nanochannels. The efficiency of the molecular pump depends on the angle and apertures of the asymmetric channel, the environmental temperature and average concentration of the particles. The pumping effect can be explained as the competition between the molecular force field and the thermal disturbance. Our results provide a green approach for pumping fluid particles against the concentration gradient through asymmetric nanoscale thin films without any external forces. It indicates that pumping vacuum can be a spontaneous process. PMID:26996204

  19. Energy 101: Concentrating Solar Power

    ScienceCinema

    None

    2013-05-29

    From towers to dishes to linear mirrors to troughs, concentrating solar power (CSP) technologies reflect and collect solar heat to generate electricity. A single CSP plant can generate enough power for about 90,000 homes. This video explains what CSP is, how it works, and how systems like parabolic troughs produce renewable power. For more information on the Office of Energy Efficiency and Renewable Energy's CSP research, see the Solar Energy Technology Program's Concentrating Solar Power Web page at http://www1.eere.energy.gov/solar/csp_program.html.

  20. Copper leaching from chalcopyrite concentrates

    NASA Astrophysics Data System (ADS)

    Wang, Shijie

    2005-07-01

    Chalcopyrite (CuFeS2) is one of the most abundant copper-bearing minerals, which accounts for approximately 70 percent of the world’s known copper reserves. For more than 30 years, a significant number of processes have been developed to leach copper from chalcopyrite concentrates. These processes recover copper via hydrometallurgical leaching of the copper component of chalcopyrite concentrates, followed by solvent extraction and electrowinning. A number of demonstration plant operations have been conducted, but as of this writing none of the processes have become completely commercially operational.

  1. Assessing physiological complexity.

    PubMed

    Burggren, W W; Monticino, M G

    2005-09-01

    Physiologists both admire and fear complexity, but we have made relatively few attempts to understand it. Inherently complex systems are more difficult to study and less predictable. However, a deeper understanding of physiological systems can be achieved by modifying experimental design and analysis to account for complexity. We begin this essay with a tour of some mathematical views of complexity. After briefly exploring chaotic systems, information theory and emergent behavior, we reluctantly conclude that, while a mathematical view of complexity provides useful perspectives and some narrowly focused tools, there are too few generally practical take-home messages for physiologists studying complex systems. Consequently, we attempt to provide guidelines as to how complex systems might be best approached by physiologists. After describing complexity based on the sum of a physiological system's structures and processes, we highlight increasingly refined approaches based on the pattern of interactions between structures and processes. We then provide a series of examples illustrating how appreciating physiological complexity can improve physiological research, including choosing experimental models, guiding data collection, improving data interpretations and constructing more rigorous system models. Finally, we conclude with an invitation for physiologists, applied mathematicians and physicists to collaborate on describing, studying and learning from studies of physiological complexity. PMID:16109885

  2. A basal carbon concentrating mechanism in plants?

    PubMed

    Zabaleta, Eduardo; Martin, M Victoria; Braun, Hans-Peter

    2012-05-01

    Many photosynthetic organisms have developed inorganic carbon (Ci) concentrating mechanisms (CCMs) that increase the CO₂ concentration within the vicinity of ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO). Several CCMs, such as four carbon (C4) and crassulacean acid metabolism (CAM), bicarbonate accumulation systems and capsular structures around RubisCO have been described in great detail. These systems are believed to have evolved several times as mechanisms that acclimate organisms to unfavourable growth conditions. Based on recent experimental evidence we propose the occurrence of another more general CCM system present in all plants. This basal CCM (bCCM) is supposed to be composed of mitochondrial carbonic anhydrases (a β-type carbonic anhydrase and the γ-type carbonic anhydrase domain of the mitochondrial NADH dehydrogenase complex) and probably further unknown components. The bCCM is proposed to reduce leakage of CO₂ from plant cells and allow efficient recycling of mitochondrial CO₂ for carbon fixation in chloroplasts. PMID:22404837

  3. Solar Concentration for Electricity and Cooking

    NASA Astrophysics Data System (ADS)

    Kim, Mike; Fourt, Connor; Schwartz, Pete; Lee, Michael; Frostholm, Taylor; Fernandes, Josh; Tower, Jared

    2012-11-01

    Over 8000 Schefflers exist worldwide, mostly in Africa and Asia. Having constructed the first Scheffler reflector in North America 2 years ago, the next goal was to make it less expensive. The original model took 4 students 2 months and about 1000. In order to lower the cost and construction time the design was minimized, less expensive materials were used, and the construction process was automated. The original complex frame took 1000 people-hours and it was minimized to a day. Instead of using aluminum for the reflective dish, we turned to using aluminized Mylar, which cut the cost by over 90%. A thermal storage unit was added to extend cooking time well into the evening. Finally, a concentrated solar module of High Efficiency Photo Voltaics (HEPV) is to be placed at the focus of the concentrator to generate electricity and water as a byproduct. The final cost is estimated to be about 200 (0.10 per thermal watt) including the HEPV, an 80% cost reduction. Such technology is practical in the U.S. as well as developing nations.

  4. DIALYSIS FLASK FOR CONCENTRATED CULTURE OF MICROORGANISMS

    PubMed Central

    Gerhardt, Philipp; Gallup, D. M.

    1963-01-01

    Gerhardt, Philipp (The University of Michigan, Ann Arbor), and D. M. Gallup. Dialysis flask for concentrated culture of microorganisms. J. Bacteriol 86:919–929. 1963.—A twin-chambered dialysis flask was designed with a supported membrane clamped between a reservoir of medium in the bottom and a small volume of culture above, the unit being mounted on a shaking machine to provide aeration and agitation. The performance of different dialysis membranes and membrane filters was compared in glucose-diffusion and bacterial-culture tests. Some of the variables in dialysis culture were assessed and the growth response was characterized, with Serratia marcescens as the test organism. The general usefulness and concentrating effect of dialysis culture were demonstrated in trials with 16 representative types of microorganisms. Dialysis culture was shown to be especially suitable for producing dense populations of cells or their macromolecular products in an environment free from complex medium constituents, for removing toxic products that limit growth or fermentation, and for supplying oxygen by diffusion without the damage from usual aeration procedures. Images PMID:14080802

  5. Microstructure and momentum transport in concentrated suspensions

    SciTech Connect

    Mondy, L.A.; Graham, A.L.; Brenner, H.

    1996-06-01

    This paper reviews several coupled theoretical and experimental investigations of the effect of microstructure on momentum transport in concentrated suspensions. An expression to predict the apparent suspension viscosity of mixtures of rods and spheres is developed and verified with falling-ball viscometry experiments. The effects of suspension-scale slip (relative to the bulk continuum) are studied with a sensitive spinning-ball rheometer, and the results are explained with a novel theoretical method. The first noninvasive, nuclear magnetic resonance imaging measurements of the evolution of velocity and concentration profiles in pressure-driven entrance flows of initially well mixed suspensions in a circular conduit are described, as well as more complex two-dimensional flows with recirculation, e.g. flow in a journal bearing. These data in nonhomogeneous flows and complementary three-dimensional video imaging of individual tracer particles in homogeneous flows are providing much needed information on the effects of flow on particle interactions and effective theological properties at the macroscale.

  6. Arsenic at very low concentrations alters glucocorticoid receptor (GR)-mediated gene activation but not GR-mediated gene repression: complex dose-response effects are closely correlated with levels of activated GR and require a functional GR DNA binding domain.

    PubMed

    Bodwell, Jack E; Kingsley, Lauren A; Hamilton, Joshua W

    2004-08-01

    Arsenic (As) contamination of drinking water is considered a principal environmental health threat throughout the world. Chronic intake is associated with an increased risk of cancer, diabetes, and cardiovascular disease, and recent studies suggest increased health risks at levels as low as 5-10 ppb. We report here that 0.05-1 microM (6-120 ppb) As showed stimulatory effects on glucocorticoid receptor (GR)-mediated gene activation in rat EDR3 hepatoma cells of both the endogenous tyrosine aminotransferase (TAT) gene and the reporter genes containing TAT glucocorticoid response elements. At slightly higher concentrations (1-3 microM), the effects of As became inhibitory. Thus, over this narrow concentration range, the effects of As changed from a 2- to 4-fold stimulation to a greater than 2-fold suppression in activity. Interestingly, the inhibitory effect of GR on both AP1- and NF-kappa B-mediated gene activation was not affected by As. The magnitude of GR stimulation and inhibition by As was highly dependent on the cellular level of hormone-activated GR. Mutational deletion studies indicated that the central DNA binding domain (DBD) of GR is the minimal region required for the As effect and does not require free sulfhydryls. Point mutations located within the DBD that have known structural consequences significantly altered the GR response to As. In particular, point mutations in the DBD that confer a DNA-bound GR confirmation abolished the low dose As stimulatory effect but enhanced the inhibitory response, further indicating that the DBD is important for mediating these As effects. PMID:15310238

  7. The inhibition of thrombin-dependent positive-feedback reactions is critical to the expression of the anticoagulant effect of heparin.

    PubMed Central

    Ofosu, F A; Sie, P; Modi, G J; Fernandez, F; Buchanan, M R; Blajchman, M A; Boneu, B; Hirsh, J

    1987-01-01

    Heparin catalyses the inhibition of two key enzymes of blood coagulation, namely Factor Xa and thrombin, by enhancing the antiproteinase activities of plasma antithrombin III and heparin cofactor II. In addition, heparin can directly inhibit the activation of Factor X and prothrombin. The contributions of each of these effects to the anticoagulant activity of heparin have not been delineated. We therefore performed experiments to assess how each of these effects of heparin contributes to its anticoagulant activity by comparing the effects of heparin, pentosan polysulphate and D-Phe-Pro-Arg-CH2Cl on the intrinsic pathway of coagulation. Unlike heparin, pentosan polysulphate catalyses only the inhibition of thrombin by plasma. D-Phe-Pro-Arg-CH2Cl is rapid enough an inhibitor of thrombin so that when added to plasma no complexes of thrombin with its inhibitors are formed, whether or not the plasma also contains heparin. Heparin (0.66 microgram/ml) and pentosan polysulphate (6.6 micrograms/ml) completely inhibited the intrinsic-pathway activation of 125I-prothrombin to 125I-prothrombin fragment 1 + 2 and 125I-thrombin. On the addition of thrombin, a good Factor V activator, to the plasma before each sulphated polysaccharide, the inhibition of prothrombin activation was demonstrable only in the presence of higher concentrations of the sulphated polysaccharide. D-Phe-Pro-Arg-CH2Cl also completely inhibited the intrinsic-pathway activation of prothrombin in normal plasma. The inhibitory effect of D-Phe-Pro-Arg-CH2Cl was reversed if thrombin was added to the plasma before D-Phe-Pro-Arg-CH2Cl. The inhibition of the activation of prothrombin by the three agents was also abolished with longer times with re-added Ca2+. Reversal of the inhibitory effects of heparin and pentosan polysulphate was associated with the accelerated formation of 125I-thrombin-antithrombin III and 125I-thrombin-heparin cofactor complexes respectively. These results suggest that the anticoagulant

  8. Hypergraph coloring complexes.

    PubMed

    Breuer, Felix; Dall, Aaron; Kubitzke, Martina

    2012-08-28

    The aim of this paper is to generalize the notion of the coloring complex of a graph to hypergraphs. We present three different interpretations of those complexes-a purely combinatorial one and two geometric ones. It is shown, that most of the properties, which are known to be true for coloring complexes of graphs, break down in this more general setting, e.g., Cohen-Macaulayness and partitionability. Nevertheless, we are able to provide bounds for the [Formula: see text]- and [Formula: see text]-vectors of those complexes which yield new bounds on chromatic polynomials of hypergraphs. Moreover, though it is proven that the coloring complex of a hypergraph has a wedge decomposition, we provide an example showing that in general this decomposition is not homotopy equivalent to a wedge of spheres. In addition, we can completely characterize those hypergraphs whose coloring complex is connected. PMID:23483700

  9. Artistic forms and complexity.

    PubMed

    Boon, J-P; Casti, J; Taylor, R P

    2011-04-01

    We discuss the inter-relationship between various concepts of complexity by introducing a complexity 'triangle' featuring objective complexity, subjective complexity and social complexity. Their connections are explored using visual and musical compositions of art. As examples, we quantify the complexity embedded within the paintings of the Jackson Pollock and the musical works of Johann Sebastian Bach. We discuss the challenges inherent in comparisons of the spatial patterns created by Pollock and the sonic patterns created by Bach, including the differing roles that time plays in these investigations. Our results draw attention to some common intriguing characteristics suggesting 'universality' and conjecturing that the fractal nature of art might have an intrinsic value of more general significance. PMID:21382264

  10. TRENDS IN RURAL SULFUR CONCENTRATIONS

    EPA Science Inventory

    This paper presents an analysis of regional trends in atmospheric concentrations in sulfur dioxide (502) and particulate sulfate (50~- ) at rural monitoring sites in the Clean Air Act Status and Trends Monitoring Network (CAsTNet) from 1990 to 1999. A two-stage approach is used t...

  11. City scale pollen concentration variability

    NASA Astrophysics Data System (ADS)

    van der Molen, Michiel; van Vliet, Arnold; Krol, Maarten

    2016-04-01

    Pollen are emitted in the atmosphere both in the country-side and in cities. Yet the majority of the population is exposed to pollen in cities. Allergic reactions may be induced by short-term exposure to pollen. This raises the question how variable pollen concentration in cities are in temporally and spatially, and how much of the pollen in cities are actually produced in the urban region itself. We built a high resolution (1 × 1 km) pollen dispersion model based on WRF-Chem to study a city's pollen budget and the spatial and temporal variability in concentration. It shows that the concentrations are highly variable, as a result of source distribution, wind direction and boundary layer mixing, as well as the release rate as a function of temperature, turbulence intensity and humidity. Hay Fever Forecasts based on such high resolution emission and physical dispersion modelling surpass traditional hay fever warning methods based on temperature sum methods. The model gives new insights in concentration variability, personal and community level exposure and prevention. The model will be developped into a new forecast tool to serve allergic people to minimize their exposure and reduce nuisance, coast of medication and sick leave. This is an innovative approach in hay fever warning systems.

  12. Ambient Concentrations of Carbon Monoxide

    EPA Science Inventory

    This indicator presents trends in ambient carbon monoxide concentrations across the U.S. from 1980 to 2009. By tracking ambient carbon monoxide (CO) – a criteria pollutant with the potential to cause cardiovascular and neurological damage – this dataset shows how a...

  13. Flow properties of concentrated suspensions

    NASA Technical Reports Server (NTRS)

    Hattori, K.; Izumi, K.

    1984-01-01

    The viscosity and flow behavior of a concentrated suspension, with special emphasis on fresh concrete containing a superplasticizer, is analyzed according to Newton's law of viscosity. The authors interpreted Newton's law in a new way, and explain non-Newton flow from Newton's law. The outline of this new theory is given. Viscosity of suspensions, and the effect of dispersants are analyzed.

  14. Cesium Concentration in MCU Solvent

    SciTech Connect

    Walker, D

    2006-01-18

    During Modular Caustic-Side Solvent Extraction (CSSX) Unit (MCU) operations, Cs-137 concentrations in product streams will vary depending on the location in the process and on the recent process conditions. Calculations of cesium concentrations under a variety of operating conditions reveal the following: (1) Under nominal operations with salt solution feed containing 1.1 Ci Cs-137 per gallon, the maximum Cs-137 concentration in the process will occur in the strip effluent (SE) and equal 15-16.5 Ci/gal. (2) Under these conditions, the majority of the solvent will contain 0.005 to 0.01 Ci/gal, with a limited portion of the solvent in the contactor stages containing {approx}4 Ci/gal. (3) When operating conditions yield product near 0.1 Ci Cs-137/gal in the decontaminated salt solution (DSS), the SE cesium concentration will be the same or lower than in nominal operations, but majority of the stripped solvent will increase to {approx}2-3 Ci/gal. (4) Deviations in strip and waste stream flow rates cause the largest variations in cesium content: (a) If strip flow rates deviate by -30% of nominal, the SE will contain {approx}23 Ci/gal, although the cesium content of the solvent will increase to only 0.03 Ci/gal; (b) If strip flow rate deviates by -77% (i.e., 23% of nominal), the SE will contain 54 Ci/gal and solvent will contain 1.65 Ci/gal. At this point, the product DSS will just reach the limit of 0.1 Ci/gal, causing the DSS gamma monitors to alarm; and (c) Moderate (+10 to +30%) deviations in waste flow rate cause approximately proportional increases in the SE and solvent cesium concentrations. Recovery from a process failure due to poor cesium stripping can achieve any low cesium concentration required. Passing the solvent back through the contactors while recycling DSS product will produce a {approx}70% reduction during one pass through the contactors (assuming the stripping D value is no worse than 0.36). If the solvent is returned to the solvent hold tank

  15. Complexation of Optoelectronic Systems

    NASA Astrophysics Data System (ADS)

    Boreisho, A. S.; Il‧in, M. Yu.; Konyaev, M. A.; Mikhailenko, A. S.; Morozov, A. V.; Strakhov, S. Yu.

    2016-06-01

    Problems of increasing the efficiency and the functionality of complex optoelectronic systems for monitoring real atmospheric conditions and of their use are discussed. It is shown by the example of a meteorological complex comprising an infrared wind-sensing lidar and an X-range Doppler radar that the complexation of probing systems working in different electromagnetic-radiation ranges opens up new opportunities for determining the meteorological parameters of a turbulent atmosphere and investigating the interaction of radiation with it.

  16. BIOASSAY OF COMPLEX MIXTURES OF INDOOR AIR POLLUTANTS

    EPA Science Inventory

    Indoor air pollution is a complex mixture of chemicals originating from outdoor air and indoor sources. oxicology studies of these mixtures are limited by difficulties in obtaining indoor air samples or appropriately simulated exposures. he concentration of pollutants from indoor...

  17. Complexity and schizophrenia.

    PubMed

    Fernández, Alberto; Gómez, Carlos; Hornero, Roberto; López-Ibor, Juan José

    2013-08-01

    Complexity estimators have been broadly utilized in schizophrenia investigation. Early studies reported increased complexity in schizophrenia patients, associated with a higher variability or "irregularity" of their brain signals. However, further investigations showed reduced complexities, thus introducing a clear divergence. Nowadays, both increased and reduced complexity values are reported. The explanation of such divergence is a critical issue to understand the role of complexity measures in schizophrenia research. Considering previous arguments a complementary hypothesis is advanced: if the increased irregularity of schizophrenia patients' neurophysiological activity is assumed, a "natural" tendency to increased complexity in EEG and MEG scans should be expected, probably reflecting an abnormal neuronal firing pattern in some critical regions such as the frontal lobes. This "natural" tendency to increased complexity might be modulated by the interaction of three main factors: medication effects, symptomatology, and age effects. Therefore, young, medication-naïve, and highly symptomatic (positive symptoms) patients are expected to exhibit increased complexities. More importantly, the investigation of these interacting factors by means of complexity estimators might help to elucidate some of the neuropathological processes involved in schizophrenia. PMID:22507763

  18. Blood levels of histone-complexed DNA fragments are associated with coagulopathy, inflammation and endothelial damage early after trauma

    PubMed Central

    Johansson, Pär I; Windeløv, Nis A; Rasmussen, Lars S; Sørensen, Anne Marie; Ostrowski, Sisse R

    2013-01-01

    Background: Tissue injury increases blood levels of extracellular histones and nucleic acids, and these may influence hemostasis, promote inflammation and damage the endothelium. Trauma-induced coagulopathy (TIC) may result from an endogenous response to the injury that involves the neurohumoral, inflammatory and hemostatic systems. Aims: To study the contribution of extracellular nucleic constituents to TIC, inflammation and endothelial damage. Setting and Design: Prospective observational study. Materials and Methods: We investigated histone-complexed DNA fragments (hcDNA) along with biomarkers of coagulopathy, inflammation and endothelial damage in plasma from 80 trauma patients admitted directly to the Trauma Centre from the scene of the accident. Blood was sampled a median of 68 min (IQR 48-88) post injury. Trauma patients with hcDNA levels >median or ≤median were compared. Results: Trauma patients with high plasma hcDNA had higher Injury Severity Score (ISS) and level of sympathoadrenal activation (higher adrenaline and noradrenaline) and a higher proportion of prolonged activated partial thromboplastin time (APTT) and higher D-dimer, tissue-type plasminogen activator (tPA), Annexin V and soluble CD40 ligand (sCD40L) concurrent with lower plasminogen activator inhibitor (PAI)-1) and prothrombin fragment (PF) 1 + 2 (all P < 0.05), all indicative of impaired thrombin generation, hyperfibrinolysis and platelet activation. Furthermore, patients with high hcDNA had enhanced inflammation and endothelial damage evidenced by higher plasma levels of terminal complement complex (sC5b-9), IL-6, syndecan-1, thrombomodulin and tissue factor pathway inhibitor (all P < 0.05). Conclusions: Excessive release of extracellular histones and nucleic acids seems to contribute to the hypocoagulability, inflammation and endothelial damage observed early after trauma. PMID:23960372

  19. Cytokine induced changes in proteasome subunit composition are concentration dependent.

    PubMed

    Stohwasser, R; Kloetzel, P M

    1996-09-01

    In eukaryotes, 20S proteasome subunit composition is controlled by the cytokine interferon-gamma (IFN-gamma). IFN-gamma induces the synthesis of the beta-subunits LMP2, LMP7 and MECL-1, which in consequence replace their constitutive subunit homologs delta, MB1 and MC14/Z in the 20S complex. By pulse labeling mouse RMA cells and immunoprecipitation of proteasome complexes with the antibody MP3, we have analysed the effect of different IFN-gamma concentrations on proteasomal subunit composition. Our experiments show that IFN-gamma concentrations as low as 5 U/ml induce subunit substitutions and that overall proteasomal subunit composition is dependent on the cytokine concentration used. An IFN-gamma concentration of 50 U/ml is sufficient for complete replacement of subunit delta by LMP2. In contrast, IFN-gamma treatment never induces a complete replacement of subunit MC14 by MECL-1. These subunits are present at an approximate 1:1 molar ratio, suggesting that both subunits coexist in the same 20S proteasome complex. Furthermore, different regulatory mechanisms have to be postulated for the synthesis and incorporation of the three IFN-gamma inducible proteasome subunits. Both IFN-gamma as well as IL-2 also seem to influence the modification state of the alpha subunit C8. Since the subunit composition is dependent on the cytokine concentration used and strongly influences the proteolytic properties of the 20S proteasome complex, our experiments represent a caveat for experiments in which IFN-gamma dependent proteasomal enzyme characteristics have been analysed without monitoring the subunit composition. PMID:9067255

  20. Labile sulfide and sulfite in phytochelatin complexes

    SciTech Connect

    Eannetta, N.T.; Steffens, J.C. )

    1989-04-01

    Heavy metals such as cadmium induce tomato cell cultures to synthesize the metal binding polypeptides ({gamma}-Glu-Cys){sub 3} and ({gamma}-Glu-Cys){sub 4}-Gly (phytochelatins). Tomato cells selected for growth on normally lethal concentrations of CdCl{sub 2} synthesize higher quantities of these polypeptides. Cd{sup r} cells are not cross-resistant to other heavy metals, and recent work suggests that metal detoxification by these peptides may be Cd-specific. The occurrence of labile sulfur as a component of the metal complex raises questions concerning possible functions of phytochelatins besides that of Cd binding. The presence of acid-labile sulfide ion in phytochelatin complexes has been reported by several groups. We report the additional finding that labile sulfite is also present in these complexes and in higher amounts than sulfide. Sulfide and sulfite are both released from the metal binding complex by acidification or by treatment with EDTA.

  1. Groundwater cleanup demonstrations at Complex 34, CCAS

    NASA Technical Reports Server (NTRS)

    2000-01-01

    At Launch Complex 34, the Six-Phase Soil Heating site that is involved in a groundwater cleanup project can be seen. The project involves the Department of Defense, Environmental Protection Agency, Department of Energy and NASA. Concentrations of trichloroethylene solvent have been identified in the soil at the complex as a result of cleaning methods for rocket parts during the Apollo Program, which used the complex, in the 60s. The group formed the Interagency NDAPL Consortium (IDC) to study three contamination cleanup technologies: Six-Phase Soil Heating, Steam Injection and In Situ Oxidation with Potassium Permanganate. All three methods may offer a way to remove the contaminants in months instead of decades. In the background is the block house for the complex. KSC hosted a two-day conference that presented information and demonstrations of the three technologies being tested at the site.

  2. Cylindrical acoustic levitator/concentrator

    DOEpatents

    Kaduchak, Gregory; Sinha, Dipen N.

    2002-01-01

    A low-power, inexpensive acoustic apparatus for levitation and/or concentration of aerosols and small liquid/solid samples having particulates up to several millimeters in diameter in air or other fluids is described. It is constructed from a commercially available, hollow cylindrical piezoelectric crystal which has been modified to tune the resonance frequency of the breathing mode resonance of the crystal to that of the interior cavity of the cylinder. When the resonance frequency of the interior cylindrical cavity is matched to the breathing mode resonance of the cylindrical piezoelectric transducer, the acoustic efficiency for establishing a standing wave pattern in the cavity is high. The cylinder does not require accurate alignment of a resonant cavity. Water droplets having diameters greater than 1 mm have been levitated against the force of gravity using; less than 1 W of input electrical power. Concentration of aerosol particles in air is also demonstrated.

  3. Electrokinetic concentration of charged molecules

    DOEpatents

    Singh, Anup K.; Neyer, David W.; Schoeniger, Joseph S.; Garguilo, Michael G.

    2002-01-01

    A method for separating and concentrating charged species from uncharged or neutral species regardless of size differential. The method uses reversible electric field induced retention of charged species, that can include molecules and molecular aggregates such as dimers, polymers, multimers, colloids, micelles, and liposomes, in volumes and on surfaces of porous materials. The retained charged species are subsequently quantitatively removed from the porous material by a pressure driven flow that passes through the retention volume and is independent of direction thus, a multi-directional flow field is not required. Uncharged species pass through the system unimpeded thus effecting a complete separation of charged and uncharged species and making possible concentration factors greater than 1000-fold.

  4. Silicon concentrator solar cell research

    SciTech Connect

    Green, M.A.; Zhao, J.; Wang, A.; Dai, X.; Milne, A.; Cai, S.; Aberle, A.; Wenham, S.R.

    1993-06-01

    This report describes work conducted between December 1990 and May 1992 continuing research on silicon concentrator solar cells. The objectives of the work were to improve the performance of high-efficiency cells upon p-type substrates, to investigate the ultraviolet stability of such cells, to develop concentrator cells based on n-type substrates, and to transfer technology to appropriate commercial environments. Key results include the identification of contact resistance between boron-defused areas and rear aluminum as the source of anomalously large series resistance in both p- and n-type cells. A major achievement of the present project was the successful transfer of cell technology to both Applied Solar Energy Corporation and Solarex Corporation.

  5. How Concentration Shields Against Distraction

    PubMed Central

    Marsh, John E.

    2015-01-01

    In this article, we outline our view of how concentration shields against distraction. We argue that higher levels of concentration make people less susceptible to distraction for two reasons. One reason is that the undesired processing of the background environment is reduced. For example, when people play a difficult video game, as opposed to an easy game, they are less likely to notice what people in the background are saying. The other reason is that the locus of attention becomes more steadfast. For example, when people are watching an entertaining episode of their favorite television series, as opposed to a less absorbing show, attention is less likely to be diverted away from the screen by a ringing telephone. The theoretical underpinnings of this perspective, and potential implications for applied settings, are addressed. PMID:26300594

  6. Development of concentrator solar cells

    SciTech Connect

    Not Available

    1994-08-01

    A limited pilot production run on PESC silicon solar cells for use at high concentrations (200 to 400 suns) is summarized. The front contact design of the cells was modified for operation without prismatic covers. The original objective of the contract was to systematically complete a process consolidation phase, in which all the, process improvements developed during the contract would be combined in a pilot production run. This pilot run was going to provide, a basis for estimating cell costs when produced at high throughput. Because of DOE funding limitations, the Photovoltaic Concentrator Initiative is on hold, and Applied Solar`s contract was operated at a low level of effort for most of 1993. The results obtained from the reduced scope pilot run showed the effects of discontinuous process optimization and characterization. However, the run provided valuable insight into the technical areas that can be optimized to achieve the original goals of the contract.

  7. Concentrating Solar Power Fact Sheet

    SciTech Connect

    2015-12-01

    This fact sheet is an overview of the Concentrating Solar Power (CSP) subprogram at the U.S. Department of Energy SunShot Initiative. CSP is a dispatchable, renewable energy option that uses mirrors to focus and concentrate sunlight onto a receiver, from which a heat transfer fluid carries the intense thermal energy to a power block to generate electricity. CSP systems can store solar energy to be used when the sun is not shining. It will help meet the nation’s goal of making solar energy fully cost-competitive with other energy sources by the end of the decade. Worldwide, CSP activity is rapidly scaling, with approximately 10 gigawatts (GW) in various stages of operation or development. In the United States alone, nearly 2 GW of CSP are in operation.

  8. Methods for sperm concentration determination.

    PubMed

    Björndahl, Lars

    2013-01-01

    Proper assessment of the number of spermatozoa is essential not only as an initial step in every clinical infertility investigation [Björndahl et al (2010) A practical guide to basic laboratory andrology, 1st edn. Cambridge University Press, Cambridge] but also when attempting to establish the total sperm production in the testis [Amann (Hum Reprod 25:22-28, 2010); Amann (J Androl 30:626-641, 2009); Amann and Chapman (J Androl 30:642-649, 2009)]. Reliable methods combined with an understanding of the specific physiology involved as well as the main sources of errors related to the assessment of sperm concentration are critical for ensuring accurate concentration determination [Björndahl et al (2010) A practical guide to basic laboratory andrology, 1st edn. Cambridge University Press, Cambridge; World Health Organization (2010) WHO laboratory manual for the examination and processing of human semen. WHO, Geneva]. This chapter therefore focuses on these three aspects. PMID:22992898

  9. Performance Improvement Assuming Complexity

    ERIC Educational Resources Information Center

    Rowland, Gordon

    2007-01-01

    Individual performers, work teams, and organizations may be considered complex adaptive systems, while most current human performance technologies appear to assume simple determinism. This article explores the apparent mismatch and speculates on future efforts to enhance performance if complexity rather than simplicity is assumed. Included are…

  10. U1A Complex

    SciTech Connect

    2014-10-28

    Some of the most sophisticated experiments in the stockpile stewardship program are conducted in an environmentally safe manner, nearly 1000 feet below the ground at the site. The U1a complex a sprawling underground laboratory and tunnel complex is home to a number of unique capabilities.

  11. Complexity and Relations

    ERIC Educational Resources Information Center

    Lancaster, Jeanette Elizabeth

    2013-01-01

    A central feature of complexity is that it is based on non-linear, recursive relations. However, in most current accounts of complexity such relations, while non-linear, are based on the reductive relations of a Newtonian onto-epistemological framework. This means that the systems that are emergent from the workings of such relations are a…

  12. The Tom Core Complex

    PubMed Central

    Ahting, Uwe; Thun, Clemens; Hegerl, Reiner; Typke, Dieter; Nargang, Frank E.; Neupert, Walter; Nussberger, Stephan

    1999-01-01

    Translocation of nuclear-encoded preproteins across the outer membrane of mitochondria is mediated by the multicomponent transmembrane TOM complex. We have isolated the TOM core complex of Neurospora crassa by removing the receptors Tom70 and Tom20 from the isolated TOM holo complex by treatment with the detergent dodecyl maltoside. It consists of Tom40, Tom22, and the small Tom components, Tom6 and Tom7. This core complex was also purified directly from mitochondria after solubilization with dodecyl maltoside. The TOM core complex has the characteristics of the general insertion pore; it contains high-conductance channels and binds preprotein in a targeting sequence-dependent manner. It forms a double ring structure that, in contrast to the holo complex, lacks the third density seen in the latter particles. Three-dimensional reconstruction by electron tomography exhibits two open pores traversing the complex with a diameter of ∼2.1 nm and a height of ∼7 nm. Tom40 is the key structural element of the TOM core complex. PMID:10579717

  13. Gold trifluoromethyl complexes.

    PubMed

    Gil-Rubio, Juan; Vicente, José

    2015-12-01

    This article reviews the synthesis, reactivity and applications of gold trifluoromethyl complexes, which are the only isolated perfluoroalkyl complexes of gold. The most reported examples are neutral Au(i) complexes of the type [Au(CF3)L], whereas only two Au(ii) trifluoromethyl complexes have been reported, both being diamagnetic and containing a strong Au-Au bond. A number of Au(iii) trifluoromethyl complexes have been prepared by oxidative addition of halogens or iodotrifluoromethane to Au(i) complexes or, in a few cases, by transmetallation reactions. Owing to the limitations of the available synthetic methods, a lower number of examples is known, particularly for the oxidation states (ii) and (iii). Gold trifluoromethyl complexes present singular characteristics, such as thermal stability, strong Au-C bonds and, in some cases, reactive α-C-F bonds. Some of the Au(iii) complexes reported, show unusually easy reductive elimination reactions of trifluoromethylated products which could be applied in the development of gold-catalyzed processes for the trifluoromethylation of organic compounds. PMID:26169553

  14. Freestanding Complex Optical Scanners.

    ERIC Educational Resources Information Center

    Frisbie, David A.

    A complex freestanding optical mark recognition (OMR) scanner is one which is not on-line to an external processor; it has intelligence stemming from an internal processor located within the unit or system. The advantages and disadvantages of a complex OMR can best be assessed after identifying the scanning needs and constraints of the potential…

  15. COMPLEXITY IN ECOLOGICAL SYSTEMS

    EPA Science Inventory

    The enormous complexity of ecosystems is generally obvious under even the most cursory examination. In the modern world, this complexity is further augmented by the linkage of ecosystems to economic and social systems through the human use of the environment for technological pu...

  16. Bacterial formate hydrogenlyase complex

    PubMed Central

    McDowall, Jennifer S.; Murphy, Bonnie J.; Haumann, Michael; Palmer, Tracy; Armstrong, Fraser A.; Sargent, Frank

    2014-01-01

    Under anaerobic conditions, Escherichia coli can carry out a mixed-acid fermentation that ultimately produces molecular hydrogen. The enzyme directly responsible for hydrogen production is the membrane-bound formate hydrogenlyase (FHL) complex, which links formate oxidation to proton reduction and has evolutionary links to Complex I, the NADH:quinone oxidoreductase. Although the genetics, maturation, and some biochemistry of FHL are understood, the protein complex has never been isolated in an intact form to allow biochemical analysis. In this work, genetic tools are reported that allow the facile isolation of FHL in a single chromatographic step. The core complex is shown to comprise HycE (a [NiFe] hydrogenase component termed Hyd-3), FdhF (the molybdenum-dependent formate dehydrogenase-H), and three iron-sulfur proteins: HycB, HycF, and HycG. A proportion of this core complex remains associated with HycC and HycD, which are polytopic integral membrane proteins believed to anchor the core complex to the cytoplasmic side of the membrane. As isolated, the FHL complex retains formate hydrogenlyase activity in vitro. Protein film electrochemistry experiments on Hyd-3 demonstrate that it has a unique ability among [NiFe] hydrogenases to catalyze production of H2 even at high partial pressures of H2. Understanding and harnessing the activity of the FHL complex is critical to advancing future biohydrogen research efforts. PMID:25157147

  17. U1A Complex

    ScienceCinema

    None

    2015-01-09

    Some of the most sophisticated experiments in the stockpile stewardship program are conducted in an environmentally safe manner, nearly 1000 feet below the ground at the site. The U1a complex a sprawling underground laboratory and tunnel complex is home to a number of unique capabilities.

  18. Visual Complexity: A Review

    ERIC Educational Resources Information Center

    Donderi, Don C.

    2006-01-01

    The idea of visual complexity, the history of its measurement, and its implications for behavior are reviewed, starting with structuralism and Gestalt psychology at the beginning of the 20th century and ending with visual complexity theory, perceptual learning theory, and neural circuit theory at the beginning of the 21st. Evidence is drawn from…

  19. Complexity in Picture Books

    ERIC Educational Resources Information Center

    Sierschynski, Jarek; Louie, Belinda; Pughe, Bronwyn

    2015-01-01

    One of the key requirements of Common Core State Standards (CCSS) in English Language Arts is that students are able to read and access complex texts across all grade levels. The CCSS authors emphasize both the limitations and lack of accuracy in the current CCSS model of text complexity, calling for the development of new frameworks. In response…

  20. SQUID With Integral Flux Concentrator

    NASA Technical Reports Server (NTRS)

    Peters, Palmer N.; Sisk, Robert C.

    1989-01-01

    In improved superconducting quantum interference device (SQUID), change in size and shape of superconducting ring improves coupling to external signal coil and eases coil-positioning tolerances. More rugged and easier to manufacture than conventional SQUID's with comparable electrical characteristics. Thin-film superconducting flux concentrator utilizes Meissner effect to deflect magnetic field of signal coil into central hole of SQUID. Used in magnetometers, ammeters, analog-to-digital converters, and related electronic applications in which high signal-to-noise ratios required.