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Sample records for prothrombin complex concentrates

  1. 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

  2. Biochemical characterization of prothrombin complex concentrates in China.

    PubMed

    Cao, Haijun; Tian, Qian; Huang, Yun; Ye, Shengliang; Xin, Ye; Lin, Fangzhao; Li, Changqing

    2015-03-01

    Despite increasing use of prothrombin complex concentrates (PCCs), there is little knowledge about the biochemical characterization of Chinese PCCs. Six Chinese PCCs were investigated and compared with PCCs (Octaplex®) from Europe. The levels of coagulation factors and inhibitors were detected. The presence of activated coagulation factors was assessed. Furthermore, their thrombin inhibitory capacities, specific activity and purity were assayed. All above parameters of biochemical properties were statistically analyzed. Chinese PCCs contained FⅡ, Ⅶ, Ⅸ and Ⅹ, protein C, S and Z, heparin and extremely low level antithrombin, as well as Octaplex®. The measured FⅨ activities were similar to those declared, however the measured potency of FⅡ, Ⅶ and Ⅹ greatly exceeded the labeled. Though all preparations were negative for activated coagulation factors in non-activated partial thromboplastin time test, the activated coagulation factor Ⅶ (FⅦa) remained in all PCCs and its content differed greatly. Overall, FⅦa content of Chinese PCCs was higher than that of Octaplex®. Further, Chinese PCCs were inferior to Octaplex® in the thrombin inhibitory capacities, specific activity and purity. In summary, compared with Octaplex®, Chinese PCCs' errors about the labeled activity of coagulation factors and probably high risks of thrombosis should be considered.

  3. The role of prothrombin complex concentrates in reversal of target specific anticoagulants.

    PubMed

    Babilonia, Katrina; Trujillo, Toby

    2014-01-01

    Over the past several years a new era for patients requiring anticoagulation has arrived. The approval of new target specific oral anticoagulants offers practitioners several advantages over traditionally used vitamin K antagonist agents including predictable pharmacokinetics, rapid onset of action, comparable efficacy and safety, all without the need for routine monitoring. Despite these benefits, hemorrhagic complicates are inevitable with any anticoagulation treatment. One of the major disadvantages of the new oral anticoagulants is lack of specific antidotes or reversal agents for patients with serious bleeding or need for urgent surgery. As use of the new target specific oral anticoagulants continues to increase, practitioners will need to understand both the pharmacodynamics and pharmacokinetic properties of the agents, as well as, the available literature with use of non-specific therapies to reverse anticoagulation. Four factor prothrombin complex concentrates have been available for several years in Europe, and recently became available in the United States with approval of Kcentra. These products have shown efficacy in reversing anticoagulation from vitamin K antagonists, however their usefulness with the new target specific oral anticoagulants is poorly understood. This article will review the properties of dabigatran, rivaroxaban and apixaban, as well as the limited literature available on the effectiveness of prothrombin complex concentrates in reversal of their anticoagulant effects. Additional studies are needed to more accurately define the role of prothrombin complex concentrates in patients with life threatening bleeding or who require emergent surgery, as current data is both limited and conflicting.

  4. The role of prothrombin complex concentrates in reversal of target specific anticoagulants

    PubMed Central

    2014-01-01

    Over the past several years a new era for patients requiring anticoagulation has arrived. The approval of new target specific oral anticoagulants offers practitioners several advantages over traditionally used vitamin K antagonist agents including predictable pharmacokinetics, rapid onset of action, comparable efficacy and safety, all without the need for routine monitoring. Despite these benefits, hemorrhagic complicates are inevitable with any anticoagulation treatment. One of the major disadvantages of the new oral anticoagulants is lack of specific antidotes or reversal agents for patients with serious bleeding or need for urgent surgery. As use of the new target specific oral anticoagulants continues to increase, practitioners will need to understand both the pharmacodynamics and pharmacokinetic properties of the agents, as well as, the available literature with use of non-specific therapies to reverse anticoagulation. Four factor prothrombin complex concentrates have been available for several years in Europe, and recently became available in the United States with approval of Kcentra. These products have shown efficacy in reversing anticoagulation from vitamin K antagonists, however their usefulness with the new target specific oral anticoagulants is poorly understood. This article will review the properties of dabigatran, rivaroxaban and apixaban, as well as the limited literature available on the effectiveness of prothrombin complex concentrates in reversal of their anticoagulant effects. Additional studies are needed to more accurately define the role of prothrombin complex concentrates in patients with life threatening bleeding or who require emergent surgery, as current data is both limited and conflicting. PMID:24742134

  5. On the use of prothrombin complex concentrate in patients with coagulopathy requiring tooth extraction.

    PubMed

    Morimoto, Yoshinari; Niwa, Hitoshi; Nakatani, Takeshi

    2010-12-01

    In patients on high-level anticoagulant therapy (prothrombin time-international normalized ratio [PT-INR] ≥ 4.5), surgical procedures can be carried out with bridging therapy using heparin. However, surgical treatment options are severely limited in patients on high-level anticoagulant therapy and who have heparin-induced thrombocytopenia (HIT), as heparin use is contraindicated. We performed tooth extraction using prothrombin complex concentrate (PCC) in 2 HIT patients on high-level anticoagulation therapy (PT-INR ≥ 4.5). Five hundred units of PCC were administered intravenously, and after 15 minutes, it was confirmed that PT-INR was less than 2.0. Tooth extraction was then performed and sufficient local hemostasis was achieved. At 3 hours after tooth extraction, PT-INR was 2.0 or higher and later increased to 4.0 or higher, but postoperative bleeding was mostly absent. When performing tooth extraction in HIT patients on high-level anticoagulant therapy, favorable hemostatic management was achieved through sufficient local hemostasis and transient warfarin reversal using PCC.

  6. Thromboembolic complications associated with the use of prothrombin complex and factor IX concentrates.

    PubMed

    Köhler, M; Hellstern, P; Lechler, E; Uberfuhr, P; Müller-Berghaus, G

    1998-09-01

    In 1994, shortly after a heat-treated prothrombin complex concentrate (PCC) had been withdrawn from the German market due to transmission of hepatitis B, the license of another brand was withdrawn, due to 3 acute fatalities associated with the use of this product. We report on the clinical data of altogether 5 patients, who died during a 3 month period in Germany after having received this brand of PCC. All patients had surgery, acquired deficiencies of coagulation factors, and underlying diseases predisposing for thrombosis or disseminated intravascular coagulation. PCC was administered for the prevention of bleeding. In three patients, a drug interaction of PCC with aprotinin may also have played a role. Several points, however, are suspicious of a major causative effect of the respective product, (a) the close temporal correlation between administration of the drug and the subsequent clinical as well as laboratory deterioration, (b) the accumulation of these adverse events in a short period of time, when the use and market share of this brand increased due to the shortage of other products, and (c) laboratory abnormalities of this brand which have been consistently observed in several in vitro studies.

  7. Increasing concentrations of prothrombin complex concentrate induce disseminated intravascular coagulation in a pig model of coagulopathy with blunt liver injury.

    PubMed

    Grottke, Oliver; Braunschweig, Till; Spronk, Henri M H; Esch, Stephanie; Rieg, Annette D; van Oerle, Rene; ten Cate, Hugo; Fitzner, Christina; Tolba, Rene; Rossaint, Rolf

    2011-08-18

    Despite increasing use of prothrombin complex concentrate (PCC) to treat hemorrhage-associated coagulopathy, few studies have investigated PCC in trauma, and there is a particular lack of safety data. This study was performed to evaluate PCC therapy in a porcine model of coagulopathy with blunt liver injury. Coagulopathy was induced in 27 anesthetized pigs by replacing approximately 70% blood volume with hydroxyethyl starch 130/0.4 and Ringer's lactate solution; erythrocytes were collected and retransfused. Ten minutes after trauma, animals randomly received PCC (35 or 50 IU/kg) or saline. Coagulation parameters including thromboelastometry, thrombin generation, and blood loss were monitored for 2 hours. Internal organs were examined macroscopically and histologically to determine the presence of emboli and assess liver injury. Total blood loss was significantly lower and survival was higher in both PCC groups versus the control group (P < .05). These outcomes appeared to be dose-independent. Thromboembolism was found in all animals treated with 50 IU/kg PCC; 44% also showed signs of disseminated intravascular coagulation. Liver injury was similar in all animals. In conclusion, 35 IU/kg PCC safely improved coagulation and attenuated blood loss. However, the higher dose of PCC (50 IU/kg) appeared to increase the risk of thromboembolism and disseminated intravascular coagulation.

  8. 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.

  9. 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

  10. 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

  11. Goal-directed coagulation management of major trauma patients using thromboelastometry (ROTEM®)-guided administration of fibrinogen concentrate and prothrombin complex concentrate

    PubMed Central

    2010-01-01

    Introduction The appropriate strategy for trauma-induced coagulopathy management is under debate. We report the treatment of major trauma using mainly coagulation factor concentrates. Methods This retrospective analysis included trauma patients who received ≥ 5 units of red blood cell concentrate within 24 hours. Coagulation management was guided by thromboelastometry (ROTEM®). Fibrinogen concentrate was given as first-line haemostatic therapy when maximum clot firmness (MCF) measured by FibTEM (fibrin-based test) was <10 mm. Prothrombin complex concentrate (PCC) was given in case of recent coumarin intake or clotting time measured by extrinsic activation test (EXTEM) >1.5 times normal. Lack of improvement in EXTEM MCF after fibrinogen concentrate administration was an indication for platelet concentrate. The observed mortality was compared with the mortality predicted by the trauma injury severity score (TRISS) and by the revised injury severity classification (RISC) score. Results Of 131 patients included, 128 received fibrinogen concentrate as first-line therapy, 98 additionally received PCC, while 3 patients with recent coumarin intake received only PCC. Twelve patients received FFP and 29 received platelet concentrate. The observed mortality was 24.4%, lower than the TRISS mortality of 33.7% (P = 0.032) and the RISC mortality of 28.7% (P > 0.05). After excluding 17 patients with traumatic brain injury, the difference in mortality was 14% observed versus 27.8% predicted by TRISS (P = 0.0018) and 24.3% predicted by RISC (P = 0.014). Conclusions ROTEM®-guided haemostatic therapy, with fibrinogen concentrate as first-line haemostatic therapy and additional PCC, was goal-directed and fast. A favourable survival rate was observed. Prospective, randomized trials to investigate this therapeutic alternative further appear warranted. PMID:20374650

  12. Guideline-concordant administration of prothrombin complex concentrate and vitamin K is associated with decreased mortality in patients with severe bleeding under vitamin K antagonist treatment (EPAHK study)

    PubMed Central

    2014-01-01

    Introduction In vitamin K antagonist (VKA)-treated patients with severe hemorrhage, guidelines recommend prompt VKA reversal with prothrombin complex concentrate (PCC) and vitamin K. The aim of this observational cohort study was to evaluate the impact of guideline concordant administration of PCC and vitamin K on seven-day mortality. Methods Data from consecutive patients treated with PCC were prospectively collected in 44 emergency departments. Type of hemorrhage, coagulation parameters, type of treatment and seven-day mortality mortality were recorded. Guideline-concordant administration of PCC and vitamin K (GC-PCC-K) were defined by at least 20 IU/kg factor IX equivalent PCC and at least 5 mg of vitamin K performed within a predefined time frame of eight hours after admission. Multivariate analysis was used to assess the effect of appropriate reversal on seven-day mortality in all patients and in those with intracranial hemorrhage (ICH). Results Data from 822 VKA-treated patients with severe hemorrhage were collected over 14 months. Bleeding was gastrointestinal (32%), intracranial (32%), muscular (13%), and “other” (23%). In the whole cohort, seven-day mortality was 13% and 33% in patients with ICH. GC-PCC-K was performed in 38% of all patients and 44% of ICH patients. Multivariate analysis showed a two-fold decrease in seven-day mortality in patients with GC-PCC-K (odds ratio (OR) = 2.15 (1.20 to 3.88); P = 0.011); this mortality reduction was also observed when only ICH was considered (OR = 3.23 (1.53 to 6.79); P = 0.002). Conclusions Guideline-concordant VKA reversal with PCC and vitamin K within eight hours after admission was associated with a significant decrease in seven-day mortality. PMID:24762166

  13. Cost-Effectiveness Analysis of Biogeneric Recombinant Activated Factor VII (AryoSeven™) and Activated Prothrombin Complex Concentrates (FEIBA™) to Treat Hemophilia A Patients with Inhibitors in Iran

    PubMed Central

    Golestani, Mina; Eshghi, Peyman; Rasekh, Hamid Reza; Cheraghali, Abdoll Majid; Salamzadeh, Jamshid; Naderi, Majid; Managhchi, Mohammad Reza; Hoorfar, Hamid; Toogeh, Gholam Reza; Imani, Ali; Khodayari, Mohammad Taghi; Habibpanah, Behnaz; Hantooshzadeh, Razieh

    2016-01-01

    Nowadays, bypassing agents such as recombinant activated factor VII (rFVIIa) and activated prothrombin complex concentrates (aPCC) are used to treat bleeding episodes in the Hemophilia patients with inhibitors. AryoSeven® is an Iranian biogeneric rFVIIa with homogeneity of efficacy and the nature to NovoSeven in a comparative trial. The current clinical trial aimed to evaluate the cost-effectiveness of FEIBA and AryoSeven® by Decision Analytic Model according to the Iranian healthcare system. An open label, multi-center, cross-over clinical trial was designed. Patients were categorized into 3 groups based on their prior tendency to one or none of the products. To determine the premium therapeutic strategy, the Incremental cost-effectiveness ratio (ICER) was calculated. Protocol F led to more treatment success in group F than the other groups (P= 0.03). Also, there was a significant statistical difference between the mean of effectiveness scores in the groups using protocol F (P = 0.01). The effectiveness of protocol F and A were 89% and 72%, respectively. ICER cost US$ to manage an episode of bleeding to get one more unit of effectiveness using FEIBA VS. AryoSeven. Although the results showed that AryoSeven was more cost-effective compared to FEIBA, the two strategies were undominated. In other words, both medicines can be applied in the first line of the treatment if the cost of FEIBA was reduced. The present clinical trial was registered at IRCT website, under ID No.2013020612380N1. PMID:27642341

  14. Cost-Effectiveness Analysis of Biogeneric Recombinant Activated Factor VII (AryoSeven™) and Activated Prothrombin Complex Concentrates (FEIBA™) to Treat Hemophilia A Patients with Inhibitors in Iran.

    PubMed

    Golestani, Mina; Eshghi, Peyman; Rasekh, Hamid Reza; Cheraghali, Abdoll Majid; Salamzadeh, Jamshid; Naderi, Majid; Managhchi, Mohammad Reza; Hoorfar, Hamid; Toogeh, Gholam Reza; Imani, Ali; Khodayari, Mohammad Taghi; Habibpanah, Behnaz; Hantooshzadeh, Razieh

    2016-01-01

    Nowadays, bypassing agents such as recombinant activated factor VII (rFVIIa) and activated prothrombin complex concentrates (aPCC) are used to treat bleeding episodes in the Hemophilia patients with inhibitors. AryoSeven® is an Iranian biogeneric rFVIIa with homogeneity of efficacy and the nature to NovoSeven in a comparative trial. The current clinical trial aimed to evaluate the cost-effectiveness of FEIBA and AryoSeven® by Decision Analytic Model according to the Iranian healthcare system. An open label, multi-center, cross-over clinical trial was designed. Patients were categorized into 3 groups based on their prior tendency to one or none of the products. To determine the premium therapeutic strategy, the Incremental cost-effectiveness ratio (ICER) was calculated. Protocol F led to more treatment success in group F than the other groups (P= 0.03). Also, there was a significant statistical difference between the mean of effectiveness scores in the groups using protocol F (P = 0.01). The effectiveness of protocol F and A were 89% and 72%, respectively. ICER cost US$ to manage an episode of bleeding to get one more unit of effectiveness using FEIBA VS. AryoSeven. Although the results showed that AryoSeven was more cost-effective compared to FEIBA, the two strategies were undominated. In other words, both medicines can be applied in the first line of the treatment if the cost of FEIBA was reduced. The present clinical trial was registered at IRCT website, under ID No.2013020612380N1.

  15. Reversal of anticoagulation with four-factor prothrombin complex concentrate without concurrent vitamin K (phytonadione) for urgent surgery in a patient at moderate-to-high risk for thromboembolism.

    PubMed

    Farley, Thomas Michael; Andreas, Elisha M

    2016-10-27

    Successful vitamin K antagonist (eg, warfarin) reversal with 4-factor prothrombin complex concentrate (4F-PCC) without vitamin K (phytonadione) for emergent surgery in a patient at moderate-to-high risk for thromboembolism is reported. This approach may decrease the risk for development of thrombus, as it limits the amount of time the patient's anticoagulation is subtherapeutic. It also may increase the risk of bleeding, so patient selection is essential if this strategy is employed. Caution must be exercised to complete the procedure or surgery in the window of peak 4F-PCC effect (∼1-6 hours postinfusion).

  16. Lupus anticoagulants form immune complexes with prothrombin and phospholipid that can augment thrombin production in flow.

    PubMed

    Field, S L; Hogg, P J; Daly, E B; Dai, Y P; Murray, B; Owens, D; Chesterman, C N

    1999-11-15

    Lupus anticoagulants (LA) are a family of autoantibodies that are associated with in vitro anticoagulant activity but a strong predisposition to in vivo thrombosis. They are directed against plasma phospholipid binding proteins, including prothrombin. We found that a murine monoclonal antiprothrombin antibody and 7 of 7 LA IgGs tested enhanced binding of prothrombin to 25:75 phosphatidyl serine:phosphatidyl choline vesicles in a concentration-dependent manner. We hypothesized that enhanced binding of prothrombin to phospholipid in the presence of LA IgG might result in increased thrombin production when reactions are performed in flow. Thrombin production by purified prothrombinase components was measured in a phospholipid-coated flow reactor. The flow reactor was incubated with prothrombin, calcium ions, and the IgGs and then perfused with prothrombin, calcium ions, the IgGs, factor Va, and factor Xa. A murine monoclonal antiprothrombin antibody and 4 of 6 LA IgGs from patients with a history of thrombosis increased thrombin production up to 100% over control in the first 15 minutes. In summary, LA IgGs concentrate prothrombin on a phospholipid surface that can augment thrombin production by prothrombinase in flow. These observations suggest that LA might propagate coagulation in flowing blood by facilitating prothrombin interaction with the damaged blood vessel wall.

  17. Assessment of thrombogenicity of activated and non-activated prothrombin concentrates in a rat model.

    PubMed Central

    Silberman, S.; Fareed, J.; Walenga, J.

    1986-01-01

    In vitro clotting activity of rats injected with different preparations of prothrombin concentrates was measured. Animals rendered deficient in vitamin K-dependent coagulation factors by early coumadin (warfarin) pretreatment, followed by injections of concentrate preparations were also evaluated. Findings indicate a dose-related response in abnormal coagulation changes demonstrable with each preparation and lack of protection of intravascular coagulation by coumadin anticoagulation. Furthermore, a role for in vivo factor VII activation of haemostasis following concentrate administration could not be elicited. PMID:3091059

  18. False Prolongation of Prothrombin Time in the Presence of a High Blood Concentration of Daptomycin.

    PubMed

    Yamada, Tomoyuki; Kato, Ryuji; Oda, Kazutaka; Tanaka, Hidema; Suzuki, Kaoru; Ijiri, Yoshio; Ikemoto, Toshiyuki; Nishihara, Masami; Hayashi, Tetsuya; Tanaka, Kazuhiko; Tamai, Hiroshi; Ukimura, Akira; Katsumata, Takahiro

    2016-10-01

    Prothrombin time (PT) can reportedly be falsely prolonged by the antimicrobial drug daptomycin (DAP), and concomitant use of phosphatidylglycerol (PG). Although high doses of DAP (>6 mg/kg/day) are recommended for severe infection and result in a high blood concentration, the extent to which high blood concentrations of DAP interfere with PT, in the presence or absence of PG, has yet to be determined when using the HemosIL RecombiPlasTin 2G (Werfen Japan, Tokyo, Japan). We examined the effects of high doses of DAP on PT using this reagent. DAP (0-500 mg/L) was added to normal plasma and plasma with an already prolonged PT in the presence or absence of liposomal amphotericin B (L-AMB, 5-50 mg/L) or COATSOME EL-01 empty cationic liposomes (CS, 25-250 mg/L). Furthermore, we undertook a Monte Carlo simulation to calculate the probability of achieving DAP concentrations >100, >200 and >500 mg/L 0-48 hr after administering 6-12 mg/kg of DAP. Apparent PT increased with increasing DAP concentration, but neither L-AMB nor CS appeared to further elevate PT when co-administered with DAP. The probability of achieving DAP concentrations >100 and >200 mg/L increased with DAP dose. Higher doses of DAP than the approved dose caused false prolongation of PT. PT should be monitored carefully in patients taking high doses of DAP; ideally, PT should be measured at the trough blood concentration of DAP. Concomitant use of L-AMB and CS did not generally further elevate PT when co-administered with DAP.

  19. 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.

  20. Effect of storage conditions on prothrombin time, activated partial thromboplastin time and fibrinogen concentration on canine plasma samples

    PubMed Central

    Casella, Stefania; Giannetto, Claudia; Giudice, Elisabetta

    2010-01-01

    The present study was to assess the effect of storage conditions on prothrombin time (PT), activated partial thromboplastin time (aPTT) and fibrinogen concentration in blood samples of healthy dogs. Thirty-five dogs of various breeds were included in the study. Citrated blood samples were obtained and plasma was divided into four aliquots to assess selected clotting parameters by means of a coagulometer. The first aliquot was analysed within 1 h after collection, while the remaining 3 were stored at 8℃ for 4, 8 and 24 h, respectively. One-way repeated measures analysis of variance documented a significant decreasing effect on PT at 24 h compared to 8 h and on fibrinogen concentration after 8 and 24 h compared to sampling time and at 4 and 24 h compared to 8 h post sampling. In conclusion, the results of this study indicate that only fibrinogen appears prone to significant decrease. In fact, aPTT is not substantially affected by refrigeration for at least 24 h post sampling and PT showed a statistical difference that does not necessary indicate biological significance as the results obtained were within reference intervals for the dog. PMID:20458152

  1. Elevated levels of antibodies against phosphatidylserine/prothrombin complex and/or cardiolipin associated with infection and recurrent purpura in a child: a forme fruste of antiphospholipid syndrome?

    PubMed

    Kinoshita, Yuri; Mayumi, Nobuko; Inaba, Motoyuki; Igarashi, Touru; Katagiri, Ichigen; Kawana, Seiji

    2015-07-15

    Antiphospholipid syndrome is an autoimmune disorder characterized by the occurrence of venous and arterial thrombosis, as well as morbidity in pregnancy, in the presence of anti-phospholipid antibodies. The diagnosis of antiphospholipid syndrome is usually established based on clinical and laboratory findings by strictly following the 2006 Sapporo classification. However, the diagnosis remains challenging owing to the ongoing debates on the serological criteria. We report a case we describe as forme fruste antiphospholipid syndrome in which these criteria were not fulfilled. Purpura appeared repeatedly in a female infant starting from the age of 6 months and following episodes of upper respiratory infections and vaccinations. The levels of anti-cardiolipin IgG antibodies and anti-phosphatidylserine/prothrombin complex antibodies were elevated in accordance with these events. Histopathological evaluation revealed multiple small vessel thrombi in the dermis and adipose tissue. After 2 weeks of treatment with aspirin and heparin, the cutaneous symptoms subsided. Infection has long been associated with antiphospholipid syndrome, and anti-phosphatidylserine/prothrombin antibodies are considered a new marker for the diagnosis of antiphospholipid syndrome. Forme fruste antiphospholipid syndrome should be considered even if the antiphospholipid syndrome diagnostic criteria are not completely fulfilled, especially in the presence of elevated levels of anti-phosphatidylserine/prothrombin antibodies and known preceding infections.

  2. Genetics Home Reference: prothrombin thrombophilia

    MedlinePlus

    ... Understand Genetics Home Health Conditions prothrombin thrombophilia prothrombin thrombophilia Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Prothrombin thrombophilia is an inherited disorder of blood clotting . Thrombophilia ...

  3. 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.

  4. Antibodies to phosphatidylserine/prothrombin complex in suspected antiphospholipid syndrome in the absence of antibodies to cardiolipin or Beta-2-glycoprotein I.

    PubMed

    Sanfelippo, M J; Joshi, A; Schwartz, Sl; Meister, J A; Goldberg, J W

    2013-11-01

    Antibodies to phosphatidylserine/prothrombin (aPS/PT) complex were measured in 728 serum specimens from patients suspected of having antiphospholipid syndrome (APS), but without diagnostic elevations in the levels of antibodies to cardiolipin or Beta-2 Glycoprotein 1 (β2-GP1). Of the 728 specimens, 41 had elevated levels of aPS/PT. Thrombotic events occurred in 11 of the 22 patients with accessible medical histories. Six of the patients with accessible medical records also had laboratory evidence of the lupus anticoagulant. The identification of aPS/PT in patients without evidence of antibodies to cardiolipin, β2-GP1, or the lupus anticoagulant can contribute to the identification of APS in patients that may go undetected with current testing methods.

  5. Congenital prothrombin deficiency.

    PubMed

    Lancellotti, Stefano; De Cristofaro, Raimondo

    2009-06-01

    Prothrombin deficiency is among the rarest inherited coagulation disorders, with a prevalence of approximately 1:2,000,000. Two main phenotypes can be distinguished: (1) hypoprothrombinemia (type I deficiency), characterized by concomitantly low levels of activity and antigen; and (2) dysprothrombinemia (type II deficiency), characterized by the normal or near-normal synthesis of a dysfunctional protein. In some cases, hypoprothrombinemia associated with dysprothrombinemia was also described in compound heterozygous defects. No living patient with undetectable plasma prothrombin has been reported to date. Prothrombin is encoded by a gene of approximately 21 kb located on chromosome 11 and containing 14 exons. Forty different mutations have been identified and characterized in prothrombin deficiency. Many of them surround the catalytic site, whereas another "hot spot" is localized in the recognition domain called anion binding exosite I, also called fibrinogen recognition site. Recently, mutations were identified also in the Na (+)-binding loop and in the light A-chain of thrombin. Most hypoprothrombinemia-associated mutations are missense, but there are also nonsense mutations leading to stop codons and one single nucleotide deletion. Finally, the main aspects of clinical manifestations and therapy of congenital prothrombin deficiency are presented and discussed.

  6. Thrombin Generation Capacity of Prothrombin Complex Concentrate in an In Vitro Dilutional Model

    PubMed Central

    Grottke, Oliver; Rossaint, Rolf; Henskens, Yvonne; van Oerle, Rene; ten Cate, Hugo; Spronk, Henri M. H.

    2013-01-01

    Background The use of PCC for the treatment of trauma-induced coagulopathy potentially increase the risk of thromboembolism and disseminated intravascular coagulation, which is addressed to an imbalance of both pro- and anticoagulants. As PCCs differ in composition, we used an in vitro dilutional approach to assess the overall thrombin generation of five different PCCs through various laboratory assays. Methods The vitamin K-dependent coagulation factors, heparin, and antithrombin were assessed in five commercially available PCCs. The procoagulant potential of the PCCs was assessed in plasma and whole blood from 4 healthy donors by means of classical coagulation assays, thrombin generation assay and thromboelastometry. In order to reflect coagulopathy, whole blood was diluted to 80, 60, 40, and 20% with Ringer’s lactate solution. Results The five different PCCs were characterised by comparable levels of factors II, VII, IX and X (all around 20–30 IU/mL), whereas the heparin (0 to 17.6 IU/mL) and antithrombin (0.06 to 1.29 IU/mL) levels were remarkably different between manufactures. In vitro dilution of blood induced a prolongation of the PT and aPTT, and attenuation of thrombin generation and ExTem induced thromboelastometry. Overall, non- or low-heparin containing PCCs restored the in vitro dilutional coagulopathy, whereas PCCs containing heparin have an anticoagulant effect. The thrombin generation assay showed to be the most sensitive method for assessment of PCC effects. Conclusions This study shows that most available PCCs are not balanced regarding their pro- and anticoagulants. The effect of measured differences in thrombin generation among different PCCs requires further investigations to elaborate the clinical meaning of this finding in the treatment of trauma induced coagulopathy. PMID:23696866

  7. Prothrombin Segovia: a new congenital abnormality of prothrombin.

    PubMed

    Rocha, E; Paramo, J A; Bascones, C; Fisac, P R; Cuesta, B; Fernandez, J

    1986-05-01

    A family with a new congenital dysprothrombinemia is presented. The propositus is a 21-yr-old man who presented simultaneously with hemartrosis of the left knee and an extensive hematoma following a minor trauma. Prothrombin time and activated partial thromboplastin time were prolonged. Prothrombin activity was very low when measured by biological assay using physiological activators (7% by one-stage method and 20% by two-stage method) or a Russel's viper venom-cephalin mixture (23%), Notechis scutatus scutatus venom (15%) and Echis carinatus venom (17%); in contrast, the level was found to be borderline to normal using Taipan viper venom (64%) and normal by both staphylocoagulase and immunologic methods. Family studies revealed consanguinity between the propositus' mother and father and both presented a 50% reduced prothrombin level when physiological activators or Echis carinatus viper venom were used. A line of identity between normal and abnormal prothrombin was observed on immunodiffusion. The migration of the abnormal prothrombin was less anodic and was not changed by the addition of calcium. The patient's serum showed 3 bands in the bidimensional immunoelectrophoresis system, whereas normal serum showed only 2 bands. The term prothrombin Segovia is proposed to define this new prothrombin abnormality.

  8. Genetics Home Reference: prothrombin deficiency

    MedlinePlus

    ... instructions for making the prothrombin protein (also called coagulation factor II), which plays a critical role in ... on PubMed (1 link) PubMed OMIM (1 link) COAGULATION FACTOR II Sources for This Page Akhavan S, Mannucci ...

  9. Oral contraceptives and the prothrombin time.

    PubMed

    Pangrazzi, J; Roncaglioni, M C; Donati, M B

    1980-02-02

    Dr. De Teresa and others reported that mean prothrombin time ratio of 12 patients on long-term anticoagulation with warfarin was significantly higher when they were also taking oral contraceptives (OCs). A study of prothrombin complex activity was recently conducted in female rats treated with an estrogen-progestogen combination (lynestrenol 5 mg; mestranol 0.3 mg/kg body weight) which resulted in a 100% infertility in this species. After 1 treatment for only 1 estral cycle, OC-treated rats had a significantly longer Normotest clotting time (37.7+ or-0.5 sec) than control rats (31.0+or-0.4); the difference was even more notable after 10 cycles. Although this finding has not been reported in women on OCs, it may be that the estrogen-induced "lability" of the prothrombin complex occurs in humans only in special conditions, such as anticoagulation. Alternatively, liver dysfunction occurring among women on OCs may be responsible for reduced metabolism of warfarin, contributing to the effectiveness of the anticoagulation. Further pharmacology studies should be done to clarify the interaction between OCs and oral anticoagulants.

  10. Structure/function relationships of bovine prothrombin fragment 1

    SciTech Connect

    Pollock, J.S.

    1987-01-01

    The objective of this investigation was to evaluate the unique contribution of the N-terminal 33 residues of prothrombin, the Gla domain, to the Ca(II) and phospholipid binding properties of prothrombin. Prothrombin fragment 1 contains the Gla domain and is often used to study the Ca(II) and phospholipid binding properties of prothrombin. Two Gla domain peptides, 1-42 and 1-45, produced by chymotryptic cleavage of F-1 and isolated by anion-exchange chromatography were utilized to characterize the Gla domain of prothrombin. All experiments with Gla domain peptides was conducted at Ca(II) concentrations less than 2 mM since these peptides will precipitate from the solution at Ca(II) concentrations greater than 2 mM. Examinations of the properties of the Gla domain peptides was undertaken by several experimental approaches. In contrast to F-1, the intrinsic fluorescence of both 1-42 and 1-45 was not quenched upon the addition of 1 mM Ca(II) or any concentration of Mg(II). Equilibrium dialysis studies indicated that 1-42 binds three Ca(II) ions non-cooperatively. Similar studies using F-1 have shown positive cooperativity and seven Ca(II) ion binding sites. Gel permeation chromatography revealed that radioiodinated 1-45 dimerizes at the peptide concentration utilized in the equilibrium dialysis studies.

  11. Purification and properties of prothrombin modified by asbestos filtration of human plasma.

    PubMed

    Izuchi, Y; Boffa, M C; Soulier, J P

    1979-02-15

    Filtration through asbestos filter (Seitz) of human plasma modified the prothrombin molecule as previously shown. Factor II could no longer be activated by physiological activators (Ca++ + phospholipid + V and Xa) but reacted readily with staphylocoagulase. The separation and purification of the modified prothrombin allowed allowed the preparation of two fractions: A small slightly modified accessory fraction, "prothrombin-asbestos-1", lost its ability to be activated by physiological activators, and its ability to be adsorbed by barium citrate, but retained the immunological reactivity of fragment 1, as well as the mobility and molecular weight of unmodified prothrombin. A main fraction, "prothrombin-asbestos-2" appeared to be a modified prothrombin which has lost its N-terminal extremity. It was not adsorbed by barium citrate and could not be activated by physiological activators. It possessed a reduced electrophoretic mobility, as well as a reduced molecular weight (39,000), which are properties similar to those of thrombin. Both fractions 1 and 2 were devoid of thrombin activity. Asbestos was thus able to break the prothrombin molecule non enzymatically, the amputation of the N terminal extremity being responsible for the new functional and physicochemical properties of the molecule. Staphylocoagulase appeared not to need the N terminal extremity of the molecule of prothrombin to form the active thrombin-coagulase complex.

  12. 21 CFR 866.5735 - Prothrombin immunological test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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...

  13. 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...

  14. 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...

  15. 21 CFR 866.5735 - Prothrombin immunological test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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...

  16. 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...

  17. Recombinant human prothrombin reduced blood loss in a porcine model of dilutional coagulopathy with uncontrolled bleeding.

    PubMed

    Hansson, Kenny M; Johansson, Karin J; Wingren, Cecilia; Fries, Dietmar; Nelander, Karin; Lövgren, Ann

    2017-04-01

    : Uncontrolled bleeding remains one of the leading causes of trauma-induced death. Treatment recommendations focus on fresh frozen plasma and blood cell transfusions, whereas plasma concentrates or single coagulation factors have been studied in recent years. The effect of recombinant human prothrombin factor II (rhFII, 8 mg/kg), activated recombinant human factor VII (rhFVIIa, 300 μg/kg), plasma-derived human fibrinogen (pdhFib) (200 mg/kg), activated prothrombin complex concentrate (aPCC, 40 IU/kg), a three-factor combination intended as a minimal PCC (8 mg/kg rhFII, 640 μg/kg recombinant human factor X (rhFX), and 12 μg/kg rhFVIIa), and vehicle were investigated in a porcine model of dilutional coagulopathy with uncontrolled bleeding. Survival time and blood loss were determined up to 120 min after induction of liver injury. Rotational thromboelastometry EXTEM coagulation time and maximum clot firmness, prothrombin time, thrombin-antithrombin complex (TAT), thrombin generation (endogenous thrombin potential, ETP) were measured at baseline, after dilution, drug administration, and end of experiment. rhFII, the three-factor combination, and aPCC significantly (P < 0.01) decreased blood loss vs. vehicle and rhFII also vs. fibrinogen (P < 0.05). Survival times increased significantly for rhFII, aPCC, rhFVIIa, and pdhFib vs. vehicle (P < 0.05), and, coagulation time, maximum clot firmness, and prothrombin time improved in all groups. TAT and ETP increased transiently for rhFII and three-factor combination, whereas persistently increased for aPCC. PdhFib and rhFVIIa did not increase TAT and ETP. rhFII decreased blood loss and improved hemostatic markers and survival. In vivo, thrombin generation (TAT) and potential to form thrombin (ETP) were transiently elevated by rhFII. Addition of rhFVIIa and rhFX to rhFII did not further improve hemostatic efficacy.

  18. FRACTIONATION OF PLASMA GLOBULIN FOR PROTHROMBIN, THROMBOKINASE, AND ACCESSORY THROMBOPLASTIN

    PubMed Central

    Milstone, J. H.

    1951-01-01

    1. Crude globulin from more than 1,000 liters of citrated bovine plasma has been used in developing a procedure for moderately large scale separation of clotting factors. Fraction A, prothrombin, kinase, and thrombin fractions were prepared. Fraction A contained both kinase and accessory thromboplastin, the latter predominating when fraction A was diluted. 2. When prothrombin was activated by kinase, the rate of thrombin production was enhanced by the addition of platelets, or brain lipid, or dilute fraction A. These accessory thromboplastins caused this acceleration only when calcium chloride was added. Even with calcium, they were not effective unless kinase was present. 3. In contrast, the action of kinase was not entirely dependent on either ionic calcium or accessory thromboplastin. The concentrated kinase fraction activated prothrombin in the presence of excess oxalate. Although kinase often contaminates highly purified thrombins, it is probably distinct from thrombin. The ratio of kinase to thrombin was 100 times as great in the kinase fraction as in the thrombin fraction. 4. The kinase fraction, diluted 45,000-fold, to protein-nitrogen concentrations as low as 0.02 microgram per ml., accelerated the conversion of crude prokinase in three-stage tests. 5. The findings are consistent with the following concept of the basic enzymatic mechanism: See PDF for Structure It is now added that calcium and accessory thromboplastin exert their effects by impinging on the basic mechanism, in a chemically secondary or indirect manner. PMID:14873922

  19. 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.

  20. 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.

  1. Safety of Prothombin Complex Concentrate to Control Excess Bleeding During Continuous Flow LVAD Insertion.

    PubMed

    Bradford, Chad D; Stahovich, Marcia J; Dembitsky, Walter P; Adamson, Robert M; Engelbert, John J; Perreiter, Alexandra S

    2015-01-01

    In cardiovascular surgery, hemostatic complexities require the provision of blood products to control bleeding as well as the use of a number of hemostatic agents, some of which cause significant morbidity. Among these agents is prothrombin complex concentrates (PCC), however there is no clear consensus on PCC use in cardiovascular surgery. To investigate the safety of PCC in patients undergoing left ventricular assist device (LVAD) placement, we reviewed our single institution experience to examine the incidence of thromboembolic events and a variety of hospital markers including morbidity and mortality. A retrospective review was conducted of patients who underwent LVAD placement between January 2010 and October 2012. Patients who received intraoperative PCC constituted the PCC group (n = 41) and those who did not constituted the non-PCC group (n = 27). The overall incidence of thromboembolic events at 3 months postoperative was 12 (29.3%) in the PCC group compared with six (22.2%) in the non-PCC group, respectively (p > 0.05). Morbidity did not differ between groups and one patient in the PCC group died. The intraoperative use of PCC in LVAD insertion does not appear to be associated with a significant increase in thromboembolic events; however, larger randomized trials are needed to confirm these findings.

  2. A prothrombin activator from Bothrops erythromelas (jararaca-da-seca) snake venom: characterization and molecular cloning.

    PubMed

    Silva, Márcia B; Schattner, Mirta; Ramos, Celso R R; Junqueira-de-Azevedo, Inácio L M; Guarnieri, Míriam C; Lazzari, María A; Sampaio, Claudio A M; Pozner, Roberto G; Ventura, Janaina S; Ho, Paulo L; Chudzinski-Tavassi, Ana M

    2003-01-01

    A novel prothrombin activator enzyme, which we have named 'berythractivase', was isolated from Bothrops erythromelas (jararaca-da-seca) snake venom. Berythractivase was purified by a single cation-exchange-chromatography step on a Resource S (Amersham Biosciences) column. The overall purification (31-fold) indicates that berythractivase comprises about 5% of the crude venom. It is a single-chain protein with a molecular mass of 78 kDa. SDS/PAGE of prothrombin after activation by berythractivase showed fragment patterns similar to those generated by group A prothrombin activators, which convert prothrombin into meizothrombin, independent of the prothrombinase complex. Chelating agents, such as EDTA and o -phenanthroline, rapidly inhibited the enzymic activity of berythractivase, like a typical metalloproteinase. Human fibrinogen A alpha-chain was slowly digested only after longer incubation with berythractivase, and no effect on the beta- or gamma-chains was observed. Berythractivase was also capable of triggering endothelial proinflammatory and procoagulant cell responses. von Willebrand factor was released, and the surface expression of both intracellular adhesion molecule-1 and E-selectin was up-regulated by berythractivase in cultured human umbilical-vein endothelial cells. The complete berythractivase cDNA was cloned from a B. erythromelas venom-gland cDNA library. The cDNA sequence possesses 2330 bp and encodes a preproprotein with significant sequence similarity to many other mature metalloproteinases reported from snake venoms. Berythractivase contains metalloproteinase, desintegrin-like and cysteine-rich domains. However, berythractivase did not elicit any haemorrhagic response. These results show that, although the primary structure of berythractivase is related to that of snake-venom haemorrhagic metalloproteinases and functionally similar to group A prothrombin activators, it is a prothrombin activator devoid of haemorrhagic activity. This is a feature

  3. Randomized, Double-Blinded, Placebo-Controlled Trial of Fibrinogen Concentrate Supplementation After Complex Cardiac Surgery

    PubMed Central

    Ranucci, Marco; Baryshnikova, Ekaterina; Crapelli, Giulia Beatrice; Rahe-Meyer, Niels; Menicanti, Lorenzo; Frigiola, Alessandro

    2015-01-01

    Background Postoperative bleeding after heart operations is still a common finding, leading to allogeneic blood products transfusion. Fibrinogen and coagulation factors deficiency are possible determinants of bleeding. The experimental hypothesis of this study is that a first-line fibrinogen supplementation avoids the need for fresh frozen plasma (FFP) and reduces the need for any kind of transfusions. Methods and Results This was a single-center, prospective, randomized, placebo-controlled, double-blinded study. One-hundred sixteen patients undergoing heart surgery with an expected cardiopulmonary bypass duration >90 minutes were admitted to the study. Patients in the treatment arm received fibrinogen concentrate after protamine administration; patients in the control arm received saline solution. In case of ongoing bleeding, patients in the treatment arm could receive prothrombin complex concentrates (PCCs) and those in the control arm saline solution. The primary endpoint was avoidance of any allogeneic blood product. Patients in the treatment arm had a significantly lower rate of any allogeneic blood products transfusion (odds ratio, 0.40; 95% confidence interval, 0.19 to 0.84, P=0.015). The total amount of packed red cells and FFP units transfused was significantly lower in the treatment arm. Postoperative bleeding was significantly (P=0.042) less in the treatment arm (median, 300 mL; interquartile range, 200 to 400 mL) than in the control arm (median, 355 mL; interquartile range, 250 to 600 mL). Conclusions Fibrinogen concentrate limits postoperative bleeding after complex heart surgery, leading to a significant reduction in allogeneic blood products transfusions. No safety issues were raised. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT01471730. PMID:26037084

  4. Fibroblasts, glial, and neuronal cells are involved in extravascular prothrombin activation.

    PubMed

    Yamazaki, Y; Shikamoto, Y; Fukudome, K; Kimoto, M; Morita, T

    1999-10-01

    A membrane-associated prothrombin activator (MAPA) was found on various cultured cells derived from non-hematopoietic cells [Sekiya, F. et al. (1994) J. Biol. Chem. 269, 32441-32445]. In this study, we investigated the enzymatic properties of this enzyme using protease inhibitors. While the metalloproteinase inhibitor, o-phenanthroline, had no effect, some Kunitz type serine protease inhibitors attenuated MAPA activity. Recombinant tissue factor pathway inhibitor (rTFPI) also markedly reduced the activity (IC(50), 1. 3+/-0.6 x 10(-10) M). MAPA activity is, therefore, most likely to be due to factor Xa. We evaluated the effect of exogenous factor Xa on MAPA activity. Factor Xa-dependent prothrombin activation was observed on fibroblast cells (apparent K(d), 1.47+/-0.72 nM). Activation was also observed on glial and neuronal cells, which expressed MAPA activity. These results imply that membrane-bound factor Xa results in MAPA activity on these cells. Therefore, we considered the involvement of factor Va, a component of prothrombinase, in this activity. We examined whether or not the prothrombinase complex is assembled on these cells. Prothrombin was activated in a manner dependent on both exogenous factor Xa and factor Va (apparent K(d) of 0.51-1.81 nM for factor Va). These results indicate that the prothrombinase complex forms specifically on various extravascular cells. Although the prothrombinase complex can be assembled on monocytes and lymphocytes, it is not known why these cells can activate prothrombin specifically. These cells which have the capacity for prothrombin activator activity could also activate factor X; i.e. cells with factor X activation activity were able to convert prothrombin. These observations suggest that thrombin was generated via two procoagulant activities; factor X activation and subsequent prothrombinase complex formation on the surface of these cells. This mechanism may explain the various pathological states involving or resulting

  5. 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

  6. 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

  7. Anti-prothrombin (aPT) and anti-phosphatidylserine/prothrombin (aPS/PT) antibodies and the risk of thrombosis in the antiphospholipid syndrome. A systematic review.

    PubMed

    Sciascia, Savino; Sanna, Giovanni; Murru, Veronica; Roccatello, Dario; Khamashta, Munther A; Bertolaccini, Maria Laura

    2014-02-01

    Antibodies to prothrombin are detected by directly coating prothrombin on irradiated ELISA plates (aPT) or by using the phosphatidylserine/prothrombin complex as antigen (aPS/PT). Although these antibodies have both been associated with antiphospholipid syndrome (APS) and a correlation between the two assays have been reported, it seems that aPT and aPS/PT belong to different populations of autoantibodies. It was our objective to systematically review the available evidence on aPT and aPS/PT antibodies and the risk of thrombosis in APS. Medline-reports published between 1988 and 2013 investigating aPT and aPS/PT as a risk factor for thrombosis were included. Whenever possible, antibody isotype(s) and site of thrombosis were analysed. This systematic review is based on available data from more than 7,000 patients and controls from 38 studies analysing aPT and 10 aPS/PT. Antibodies to prothrombin (both aPT and aPS/PT) increased the risk of thrombosis (odds ratio [OR] 2.3; 95% confidence interval [CI] 1.72-3.5). aPS/PT seemed to represent a stronger risk factor for thrombosis, both arterial and/or venous than aPT (OR 5.11; 95%CI 4.2-6.3 and OR 1.82; 95%CI 1.44-2.75, respectively). In conclusion, routine measurement of aPS/PT (but not aPT) might be useful in establishing the thrombotic risk of patients with previous thrombosis and/or systemic lupus erythematosus. Their inclusion as laboratory criteria for the APS should be indisputably further explored.

  8. Metal ion blockage of tritium incorporation into gamma-carboxyglutamic acid of prothrombin. Stoichiometry of gamma-carboxyglutamic acid to Gd3+ for the high affinity sites

    SciTech Connect

    Bajaj, S.P.; Saini, R.; Katz, A.; Cai, G.Z.; Maki, S.L.; Brodsky, G.L.

    1988-07-15

    Prothrombin possesses two high affinity and four low affinity gamma-carboxyglutamic acid (Gla)-dependent gadolinium binding sites. Earlier work has shown that tritium can be specifically incorporated at the gamma-carbon of Gla in proteins at pH 5. In the present work we show that inclusion of saturating concentrations of Ca2+ in nondenaturing buffer systems ranging from pH 5.5 to 8.5 prevents the exchange of tritium into all 10 Gla residues of prothrombin. Similarly, saturating concentrations of Gd3+ prevent tritium incorporation into Gla at pH 5.5. Positive cooperativity was observed for the binding of Gd3+ to human prothrombin (at pH 5.5) for the two high affinity sites (Kd congruent to 35 nM). The four low affinity sites bind Gd3+ with a Kd congruent to 5 microM. Incubation of prothrombin ranging in concentrations from 10 to 40 microM with 2 eq of Gd3+ at pH 5.5 prevents 5.7 (average of seven determinations) Gla residues from tritium incorporation. Sedimentation velocity experiments conducted at pH 5.5 indicate that prothrombin in the presence of saturating concentrations of Gd3+ polymerizes, most likely, to a trimer. Further, in the presence of 2 eq of Gd3+, calculated percent weight average concentration of monomer prothrombin is congruent to 100% at 10 microM, approximately equal to 95% at 20 microM, and congruento to 80% at 40 microM protein concentration. Thus, it appears that under conditions in which prothrombin primarily exists as a monomer, occupancy of the initial two metal binding sites by Gd3+ involves six Gla residues.

  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, 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...

  11. Using the international normalized ratio to standardize prothrombin time.

    PubMed

    Stern, R; Karlis, V; Kinney, L; Glickman, R

    1997-08-01

    The international normalized ratio, or INR, was introduced in 1983 by the World Health Organization, or WHO, Committee on Biological Standards to more accurately assess patients receiving anticoagulation therapy. The INR mandates the universal standardization of prothrombin time. This article describes the method used to calculate INR, as well as its clinical relevance to the practice of dentistry.

  12. 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...

  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. 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...

  15. Location of. gamma. -carboxyglutamyl residues in partially carboxylated prothrombin preparations

    SciTech Connect

    Liska, D.J.; Suttie, J.W.

    1988-11-15

    Prothrombin contains 10-..gamma..-carboxylglutamyl (Gla) residues in the N-terminal (fragment 1) domain of the protein. Following anticoagulant administration, a spectrum of undercarboxylated, physiologically less active forms of prothrombin is secreted into bovine or human plasma. The sites of undercarboxylation in these prothrombin species have now been investigated. Plasma containing a mixture of partially carboxylated forms of prothombin was obtained from a dicoumarol-treated bovine, and three pools of partially carboxylated (four, six, or eight Gla) species were purified by adsorption onto barium citrate and barium oxalate, ammonium sulfate fractionation, and chromatography. Fragment 1 obtained from these variants was equilibrated with /sup 3/H/sub 2/O and heated in a dry state to decarboxylate Gla and incorporate /sup 3/H into the resulting Glu residues. This peptide was then sequenced by Edman degradation, and the specific radioactivity of PTH-Glu was determined for each potential Gla-containing site. Data obtained from normal prothrombin fragment 1 fit a linear model when the log of specific activity of PTH-Glu was plotted against the cycle number. Analysis of the 80% variant showed a decrease in carboxylation only in the last two Gla residues, while data obtained from the 60% variant indicated a general decrease in carboxylation from the most amino-terminal of the Gla residues. In the 40% Gla variant, all but the most amino-terminal of the Gla residues appeared to be undercarboxylated. These data indicate that the ..gamma..-carboxylation of glutamyl residues in prothrombin does not occur randomly but instead with preferential carboxylation of the most amino-terminal Gla residues. When carboxylation is limited, the impairment of carboxylation is more severe at the more carboxyl-terminal residues.

  16. Staphylococcal superantigen-like protein 10 (SSL10) inhibits blood coagulation by binding to prothrombin and factor Xa via their γ-carboxyglutamic acid (Gla) domain.

    PubMed

    Itoh, Saotomo; Yokoyama, Ryosuke; Kamoshida, Go; Fujiwara, Toshinobu; Okada, Hiromi; Takii, Takemasa; Tsuji, Tsutomu; Fujii, Satoshi; Hashizume, Hideki; Onozaki, Kikuo

    2013-07-26

    The staphylococcal superantigen-like protein (SSL) family is composed of 14 exoproteins sharing structural similarity with superantigens but no superantigenic activity. Target proteins of four SSLs have been identified to be involved in host immune responses. However, the counterparts of other SSLs have been functionally uncharacterized. In this study, we have identified porcine plasma prothrombin as SSL10-binding protein by affinity purification using SSL10-conjugated Sepharose. The resin recovered the prodomain of prothrombin (fragment 1 + 2) as well as factor Xa in pull-down analysis. The equilibrium dissociation constant between SSL10 and prothrombin was 1.36 × 10(-7) M in surface plasmon resonance analysis. On the other hand, the resin failed to recover γ-carboxyglutamic acid (Gla) domain-less coagulation factors and prothrombin from warfarin-treated mice, suggesting that the Gla domain of the coagulation factors is essential for the interaction. SSL10 prolonged plasma clotting induced by the addition of Ca(2+) and factor Xa. SSL10 did not affect the protease activity of thrombin but inhibited the generation of thrombin activity in recalcified plasma. S. aureus produces coagulase that non-enzymatically activates prothrombin. SSL10 attenuated clotting induced by coagulase, but the inhibitory effect was weaker than that on physiological clotting, and SSL10 did not inhibit protease activity of staphylothrombin, the complex of prothrombin with coagulase. These results indicate that SSL10 inhibits blood coagulation by interfering with activation of coagulation cascade via binding to the Gla domain of coagulation factor but not by directly inhibiting thrombin activity. This is the first finding that the bacterial protein inhibits blood coagulation via targeting the Gla domain of coagulation factors.

  17. Nano concentration by acoustically generated complex spiral vortex field

    NASA Astrophysics Data System (ADS)

    Tang, Qiang; Wang, Xiaofei; Hu, Junhui

    2017-03-01

    A strategy to concentrate nanoscale materials on the boundary between a nano suspension droplet and non-vibration substrate is demonstrated and analyzed. It employs the spiral vortex of acoustic streaming, generated by an ultrasonically vibrating needle parallel to and above the non-vibration substrate. The vortex drags nanoscale materials to the center of itself, forming a concentration spot. For 250 nm-diameter SiO2 nano particle suspension with an initial concentration of 0.09 mg/ml, the diameter of the concentration spot can be up to several hundred microns. The dependency of the spiral vortex field on the vibration distribution of the acoustic needle in the droplet is also clarified by experiments and computation, and the concentration conditions are obtained by analyzing the nano particle dynamics in the spiral vortex.

  18. Kinetic and equilibrium metal-ion-binding behaviour reflected in a metal-ion-dependent antigenic determinant in bovine prothrombin. Comparison with bovine prothrombin fragment 1.

    PubMed Central

    Madar, D A; Hall, T J; Hiskey, R G; Koehler, K A

    1981-01-01

    Rabbit anti-(bovine prothrombin fragment 1) antibodies were fractionated by using fragment-1 affinity chromatography in the absence of metal ions, and showed an absolute requirement for the presence of metal ions in their interactions with bovine fragment 1 or prothrombin. These antibodies were employed to evaluate both the rate constants for a protein conformation change and the equilibrium metal-ion binding to isolated bovine fragment 1 and intact prothrombin. The close similarity of the rates obtained for the conformation change in fragment 1 and those observed in prothrombin indicated that the same process is involved in both proteins and that the non-fragment-1 region of the prothrombin has essentially no effect on this process in the fragment-1 region. Equilibrium metal-ion-binding studies indicate that the details of the metal-ion-binding process in fragment 1 and prothrombin are essentially the same. We conclude that the metal-ion-binding behaviour of the fragment-1 domain of intact prothrombin is identical with that of isolated fragment 1. PMID:6171251

  19. Neutron scattering determination of the binding of prothrombin to lipid vesicles

    SciTech Connect

    Torbet, J.

    1987-12-01

    Low-angle neutron scattering is used to study the binding of human prothrombin to small single-bilayer vesicles consisting of phosphatidylcholine and phosphatidylserine (1/1 w/w). The radius of gyration of prothrombin indicates that it is an elongated molecule. The vesicles alone were not observed to coalesce, and their molecular weight, outer radius, and average surface area per lipid were respectively (1.6 +/- 0.32) x 10/sup 6/, 114 +/- 4 A, and 110 +/- 18 A/sup 2/. These values were independent of the presence of calcium and were not altered significantly by prothrombin, which binds reversibly to the vesicle outer surface with its long axis projecting approximately radially forming a 90-A thick protein shell. From the titration of the protein-vesicle interaction, the apparent dissociation constant of the binding of prothrombin to these vesicles is estimated to be 0.8 +/- 0.4 ..mu..M. At saturation, 57 +/- 7 prothrombin molecules bind, giving 25 +/- 6 lipid residues and an area of 2900 +/- 400 A/sup 2/ per prothrombin molecule on the vesicle outer surface. This area is about twice that calculated from a prolate ellipsoid model for prothrombin. However, it is close to the maximum cross-sectional area of fragment 1, the lipid binding region of prothrombin, which is coin-shaped in the high-resolution X-ray structure. This similarity suggests that prothrombin binding could be sterically limited.

  20. Blood splash in lambs-a preliminary study using the one-stage prothrombin time test.

    PubMed

    Restall, D J

    1981-02-01

    Lambs from a flock in which a high incidence of blood splash had been detected were examined using the one-stage prothrombin test. For comparison lambs from a commercial slaughter line were also examined. All the affected lambs and 35·4% from the slaughter line had extended prothrombin times, and a relationship between extended prothrombin times and the occurrence of blood splash was established. Investigation of the pastures grazed by the affected flock showed the presence of coumarin producing plants and grasses. Some coumarin drugs prolong one-stage prothrombin times, and more importantly, induce capillary fragility, thus predisposing animals to blood splash.

  1. Complex Spontaneous Flows and Concentration Banding in Active Polar Films

    NASA Astrophysics Data System (ADS)

    Giomi, Luca; Marchetti, M. Cristina; Liverpool, Tanniemola B.

    2008-11-01

    We study the dynamical properties of active polar liquid crystalline films. Like active nematic films, active polar films undergo a dynamical transition to spontaneously flowing steady states. Spontaneous flow in polar fluids is, however, always accompanied by strong concentration inhomogeneities or “banding” not seen in nematics. In addition, a spectacular property unique to polar active films is their ability to generate spontaneously oscillating and banded flows even at low activity. The oscillatory flows become increasingly complicated for strong polarity.

  2. Retraction: 'Number needed to treat with 4-factor prothrombin complex concentrate for urgent warfarin reversal' by Andrew Chua, Vishal Patel, Allison Perrin, Lee Stern, Jenifer Ehreth, Laurel Omert, Christopher Hood, Julie Farley, Michael McGlynn and Liping Huang.

    PubMed

    2017-04-01

    The above abstract from the THSNA 2016 Summit Abstract Proceedings, first published online in the American Journal of Hematology on 20 July 2016 in Wiley OnlineLibrary (www.onlinelibrary.wiley.com), and in Volume 91, Issue 9, p. E427, has been retracted by agreement between the authors, the journal Editor-in-Chief, Carlo Brugnara, and Wiley Periodicals, Inc. The retraction has been agreed due to concerns from the submitting authors that the abstract was inadvertently submitted prior to receiving approval from all authors and proper review of data analytics, thereby rendering it incomplete.

  3. Quantification of trace metals in water using complexation and filter concentration.

    PubMed

    Dolgin, Bella; Bulatov, Valery; Japarov, Julia; Elish, Eyal; Edri, Elad; Schechter, Israel

    2010-06-15

    Various metals undergo complexation with organic reagents, resulting in colored products. In practice, their molar absorptivities allow for quantification in the ppm range. However, a proper pre-concentration of the colored complex on paper filter lowers the quantification limit to the low ppb range. In this study, several pre-concentration techniques have been examined and compared: filtering the already complexed mixture, complexation on filter, and dipping of dye-covered filter in solution. The best quantification has been based on the ratio of filter reflectance at a certain wavelength to that at zero metal concentration. The studied complex formations (Ni ions with TAN and Cd ions with PAN) involve production of nanoparticle suspensions, which are associated with complicated kinetics. The kinetics of the complexation of Ni ions with TAN has been investigated and optimum timing could be found. Kinetic optimization in regard to some interferences has also been suggested.

  4. Missense mutations in the gene encoding prothrombin corresponding to Arg596 cause antithrombin resistance and thrombomodulin resistance.

    PubMed

    Takagi, Yuki; Murata, Moe; Kozuka, Toshihiro; Nakata, Yukiko; Hasebe, Ryo; Tamura, Shogo; Takagi, Akira; Matsushita, Tadashi; Saito, Hidehiko; Kojima, Tetsuhito

    2016-11-30

    Antithrombin (AT) and thrombomodulin (TM) play important roles in the process of natural anticoagulation in vivo. Recently, we reported that the prothrombin Yukuhashi mutation (p.Arg596Leu) was associated with AT and TM resistance-related thrombophilia. To assess the AT and TM resistances associated with other missense mutations by single base substitution in the Arg596 codon, we generated recombinant variants (596Gln, 596Trp, 596Gly, and 596Pro) and investigated the effects on AT and TM anticoagulant functions. All variants except 596Pro were secreted in amounts comparable to that of the wild-type but exhibited variable procoagulant activities. After a 30-minute inactivation by AT, the relative residual activity of wild-type thrombin decreased to 15 ± 4.0 %, in contrast to values of all variants were maintained at above 80 %. The thrombin-AT complex formation, as determined by enzyme-linked immunosorbent assay, was reduced with all tested variants in the presence and absence of heparin. In the presence of soluble TM (sTM), the relative fibrinogen clotting activity of wild-type thrombin decreased to 16 ± 0.12 %, whereas that of tested variants was 37 %-56 %. In a surface plasmon resonance assay, missense Arg596 mutations reduced thrombin-TM affinity to an extent similar to the reduction of fibrinogen clotting inhibition. In the presence of sTM or cultured endothelial-like cells, APC generation was enhanced differently by variant thrombins in a thrombin-TM affinity-dependent manner. These data indicate that prothrombin Arg596 missense mutations lead to AT and TM resistance in the variant thrombins and suggest that prothrombin Arg596 is important for AT- and TM-mediated anticoagulation.

  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. Cotiarinase is a novel prothrombin activator from the venom of Bothrops cotiara.

    PubMed

    Kitano, Eduardo S; Garcia, Thalita C; Menezes, Milene C; Tashima, Alexandre K; Zelanis, André; Serrano, Solange M T

    2013-08-01

    Snake venom serine proteinases (SVSPs) may affect hemostatic pathways by specifically activating components involved in coagulation, fibrinolysis and platelet aggregation or by unspecific proteolytic degradation. In this study, we purified and characterized an SVSP from Bothrops cotiara venom, named cotiarinase, which generated thrombin upon incubation with prothrombin. Cotiarinase was isolated by a two-step procedure including gel-filtration and cation-exchange chromatographies and showed a single protein band with a molecular mass of 29 kDa by SDS-polyacrylamide gel electrophoresis under reducing conditions. Identification of cotiarinase by mass spectrometric analysis revealed peptides that matched sequences of viperid SVSPs. Cotiarinase did not show fibrinogen-clotting, platelet-aggregating, fibrinogenolytic and factor X activating activities. Upon incubation with prothrombin the generation of thrombin was detected using the peptide substrate d-Phe-Pip-Arg-pNA. Moreover, mass spectrometric identification of prothrombin fragments generated by cotiarinase in the absence of co-factors (phospholipids, factor Va, factor Xa and Ca(2+) ions), indicated the limited proteolysis of this protein to release prothrombin 1, fragment 1 and thrombin. Cotiarinase is a novel SVSP that acts on prothrombin to release active thrombin that does not match any group of the current classification of snake venom prothrombin activators.

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

    PubMed Central

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

    2003-01-01

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

  8. Addition of prothrombin to plasma can result in a paradoxical increase in activated partial thromboplastin time.

    PubMed

    Hansson, Kenny M; Björkqvist, Jenny; Deinum, Johanna

    2014-12-01

    In the activated partial thromboplastin time (APTT) assay, a variety of nonphysiological reagents is used to induce contact activation. The sensitivity of the APTT response for different thrombin inhibitors has previously been found to be dependent on the used reagent. Recently, infusion of prothrombin (FII) has been used in in-vivo coagulopathy models and its effect has been analyzed in different assays. Therefore, we investigated whether the FII plasma concentration might affect APTT using different commercial reagents, applying both turbidimetry and viscometry. We compared both plasma-derived human FII (pd-hFII) and recombinant human FII (r-hFII). Similar results were found for pd-hFII and r-hFII with different APTT reagents. As expected, no effect on APTT was found by increasing the plasma concentration of FII using APTT reagents consisting of ellagic acid (Actin FS or Actin). Although with Pathromtin SL, consisting of SiO2, only a slight increase was found, with most other commercial APTT reagents, consisting of SiO2 or kaolin, APTT dose-dependently increased by increasing concentration of FII. Therefore, both Pathromtin SL and Actin FS were used to compare r-hFII and pd-hFII by determining the KM at 37C using FII-depleted plasma, providing values of 6 ± 0.3 nmol/l FII for both. Thus, at normal plasma concentrations of FII, the maximal initial thrombin generation rate should be reached and no effect on the coagulation time is expected at higher FII concentrations. To completely avoid the paradoxical effect in the APTT assay at FII concentrations higher than normal, Actin or Actin FS is the preferable reagent.

  9. Circulating microparticles in carriers of prothrombin G20210A mutation.

    PubMed

    Campello, E; Spiezia, L; Radu, C M; Gavasso, S; Zerbinati, P; Woodhams, B; Simioni, P

    2014-09-02

    Factor V Leiden (FVL) and prothrombin gene mutation G20210A (PTM) are the two most common genetic polymorphisms known to predispose carriers to venous thromboembolism (VTE). A recent study in FVL carriers showed that circulating levels of microparticles (MP) may contribute to their thrombogenic profile. To further elucidate the prothrombotic state linked to genetic thrombophilia, we extended this study to carriers of PTM. The plasma level of annexin V-MP, endothelial-MP (EMP), platelet-MP (PMP), tissue factor-bearing MP (TF+) and the MP procoagulant activity (PPL) was measured in 124 carriers of PTM (105 heterozygous and 19 homozygous) and in 120 age- and gender-matched healthy individuals. Heterozygous and homozygous carriers of PTM showed significantly increased levels of annexin V-MP (2930 [1440-4646] MP/µl and 3064 [2412-4906] MP/µl, respectively) and significantly shorter PPL clotting time (54 [46-67] sec and 55 [46-64] sec) compared to controls (1728 [782-2122] MP/µl and 71 [61-75] sec, respectively; p<0.01). Similarly, heterozygous and homozygous subjects presented with significantly higher levels of EMP, PMP and TF+ than controls (p<0.05). PTM carriers with a VTE history had significantly higher MP numbers and activity than controls. No significant difference was seen between carriers with and without a VTE history. We conclude that the higher levels of circulating MP found in PTM carriers may play a role in the development of VTE possibly by increasing thrombin generation. Further studies are needed to better define the role of MP as triggering factors for the thrombotic complications characterizing mild genetic thrombophilic defects.

  10. Formation and stabilization of anionic metal complexes in concentrated aqueous quaternary ammonium salt solutions

    SciTech Connect

    Aronson, F.L.; Hwang, L.L.Y.; Ronca, N.; Solomon, N.A.; Steigman, J.

    1985-02-04

    Anionic complexes of transition metals were stabilized in aqueous solutions containing high concentrations of various short-chain quaternary ammonium salts. Compounds with longer paraffin chains were effective in much less concentrated solution. Complex ions were detected spectrophotometrically. FeCl/sub 4//sup -/, which is usually formed in concentrated HCl, was the predominant Fe(III) complex in 30 m choline chloride containing only 0.12 M HCl. A yellow transitory Tc(VII) chloro-addition intermediate, formed in the reduction of TcO/sub 4//sup -/ by concentrated HCl, was stabilized when the solution also contained 25 m choline chloride. Its spectrum, as well as the isolation of an already known Tc(VII) bipyridyl complex, is reported. Concentrated organic electrolytes also stabilized Tc(V) oxide halides against disproportionation and Tc(IV) hexahalides against hydrolysis. Halochromates of Cr(VI) were formed and stabilized in dilute acid containing quaternary ammonium salts. Their UV spectra showed the well-resolved vibronic fine structure associated with the symmetric chromium-to-oxygen charge-transfer band. It is known that these progressions are resolved in aprotic solvents, but not in aqueous acidic solution alone, and that the loss of fine structure in aqueous media is due to hydrogen bonding. The stabilization of anionic metal complexes and the resolution of vibronic structure in halochromates are probably consequences of water-structure-enforced ion paring. The present work suggests that the water molecules in immediate contact with the complex anions are more strongly hydrogen bonded to each other than to the complex. 21 references, 4 figures.

  11. A method for systematic purification from bovine plasma of six vitamin K-dependent coagulation factors: prothrombin, factor X, factor IX, protein S, protein C, and protein Z.

    PubMed

    Hashimoto, N; Morita, T; Iwanaga, S

    1985-05-01

    A systematic purification scheme is presented for the isolation of six vitamin K-dependent coagulation factors from bovine plasma in a functionally and biochemically pure state. The vitamin K-dependent proteins concentrated by the ordinary barium citrate adsorption were first separated into four fractions, fractions A, B, C, and D, by DEAE-Sephadex A-50 chromatography. From the pooled fraction A, protein S, factor IX, and prothrombin were purified by column chromatography on Blue-Sepharose CL-6B. Heparin-Sepharose chromatography of the pooled fraction B provided mainly pure factor IX, in addition to homogeneous prothrombin. A high degree of resolution of protein C and prothrombin from the pooled fraction C was obtained with a Blue-Sepharose column. This dye-ligand chromatographic procedure was also very effective for the separation of protein Z and factor X contained in the pooled fraction D. Thus, these preparative procedures allowed high recovery of milligram and gram quantities of six vitamin K-dependent proteins from 15 liters of plasma in only two chromatographic steps, except for protein S, which required three (the third step was rechromatography on Blue-Sepharose CL-6B).

  12. 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.

  13. 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.

  14. 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.

  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.

  16. 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

  17. 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.

  18. 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.

  19. 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.

  20. [Effect of alclofenac on the prothrombin level in patients under treatment with anticoagulants].

    PubMed

    Kaufmann, E

    1977-06-25

    Simultaneous administration of the anticoagulants acenocoumarol, phenprocoumon or chlorindion and the antirheumatic substance alclofenac in long term trials has no observable influence on the prothrombin time of stabilized patients. When the anticoagulant (acenocoumarol or phenprocoumon) and the alclofenac therapy are begun simultaneously, a variation of the dose is necessary. Either a one-third lower initial dosage can be given, or, after attaining the maximal anticoagulation effect on the prothrombin time (48 h after beginning acenocoumarol therapy, 72 h with phenprocoumarol), a lower daily dosage must be administered once, in comparison to the other group without alclofenac therapy. The maintenace dosage is not influenced by alclofenac.

  1. Complexing sorbents with heterocyclic amino groups for concentrating platinum-group metals

    SciTech Connect

    Myasoedova, G.V.; Shcherbinina, N.I.; Komozin, P.N.

    1995-06-01

    Sorbents prepared on the basis of amines, in particular, those bearing heterocyclic amino groups and nitrogen-containing matrices, hold much promise for the sorptifve sepatration of platinum-group metals. The results of the study of new complexing sorbents based on 2,4,6-triamino-1,3,5-triazine (melamine) and bearing 3(5)-methylpyrazole, imidazole, and benzimidazole groups are presented in this work. The sorption and complexing properties of the sorbents with respect to platinum-group metals were studied. The possibility of using new sorbents for the group concentration of platinum-group metals was demonstrated.

  2. Dental treatment for the patient on anticoagulant therapy: prothrombin time value--what difference does it make?

    PubMed

    Benoliel, R; Leviner, E; Katz, J; Tzukert, A

    1986-08-01

    Thirty patients taking anticoagulants received routine dental treatment without altering their prothrombin time values. In a follow-up of 5 years, no serious complications were seen in patients with a prothrombin time value of up to 2.5. A protocol is suggested for dental treatment in these patients.

  3. Submitting Canine Blood for Prothrombin Time and Partial Thromboplastin Time Determinations

    PubMed Central

    Smalko, Donna; Johnstone, Ian B.; Crane, Stewart

    1985-01-01

    Practitioners commonly submit samples from dogs for partial thromboplastin time and prothrombin time determinations. Controversy exists as to the necessity for rapid separation of plasma and cells, and submission of the plasma on ice (or frozen). The purpose of this study was to address three questions. First, is it better to submit plasma or is whole blood satisfactory? Second, is it necessary to refrigerate the sample or is maintenance at room temperature (20° C) adequate? Third, does the sample have to arrive at the laboratory within a few hours of collection or can reliable partial thromboplastin time/prothrombin time determinations be made on samples up to 48 hours old? It has been shown by this study that reliable partial thromboplastin time and prothrombin time determinations can be carried out on canine plasma for up to 48 hours after collection regardless of whether or not the plasma is separated immediately; however the samples must be kept at 4°C. If the samples are maintained at room temperature, reliable prothrombin time determinations can be obtained for up to six hours after collection regardless of whether or not the plasma is separated immediately. Reliable partial thromboplastin time determinations can be made on plasma stored at 20°C for up to 24 hours after collection and possibly longer (up to 48 hours) if the plasma has been separated immediately. PMID:17422523

  4. Investigation of prothrombin time in human whole-blood samples with a quartz crystal biosensor.

    PubMed

    Müller, Lothar; Sinn, Stefan; Drechsel, Hartmut; Ziegler, Christiane; Wendel, Hans-Peter; Northoff, Hinnak; Gehring, Frank K

    2010-01-15

    Monitoring of blood coagulation and fibrinolysis is an important issue in treatment of patients with cardiovascular problems and in surgery when blood gets into contact with artificial surfaces. In this work a new method for measuring the coagulation time (prothrombin time, PT) of human whole-blood samples based on a quartz crystal microbalance (QCM) biosensor is presented. The 10 MHz sensors used in this work respond with a frequency shift to changes in viscosity during blood clot formation. For driving and for readout of the quartz, both a network analyzer and an oscillator circuit were utilized. The sensor surfaces were specifically coated with a thin polyethylene layer. We found that both frequency analysis methods are suitable to measure exact prothrombin times in a very good conformity with a mechanical coagulometer as a reference. The anticoagulant effect of heparin on the prothrombin time was exemplarily shown as well as the reverse effect of the heparin antagonist polybrene. The change of the viscoelastic properties during blood coagulation, reflected by the ratio of frequency and dissipation shifts, is discussed for different dilutions of the whole-blood samples. In conclusion, QCM is a distinguished biosensor technique to determine prothrombin time and to monitor heparin therapy in whole-blood samples. Due to the excellent potential of miniaturization and the availability of direct digital signals, the method is predestinated for incorporation and integration into other devices and is thus opening the field of application for inline coagulation diagnostic in extracorporeal blood circuits.

  5. 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

  6. Gas-phase concentration, purification, and identification of whole proteins from complex mixtures.

    PubMed

    Reid, Gavin E; Shang, Hao; Hogan, Jason M; Lee, Gil U; McLuckey, Scott A

    2002-06-26

    Five proteins present in a relatively complex mixture derived from a whole cell lysate fraction of E. coli have been concentrated, purified, and dissociated in the gas phase, using a quadrupole ion trap mass spectrometer. Concentration of intact protein ions was effected using gas-phase ion/ion proton-transfer reactions in conjunction with mass-to-charge dependent ion "parking" to accumulate protein ions initially dispersed over a range of charge states into a single lower charge state. Sequential ion isolation events interspersed with additional ion parking ion/ion reaction periods were used to "charge-state purify" the protein ion of interest. Five of the most abundant protein components present in the mixture were subjected to this concentration/purification procedure and then dissociated by collisional activation of their intact multiply charged precursor ions. Four of the five proteins were subsequently identified by matching the uninterpreted product ion spectra against a partially annotated protein sequence database, coupled with a novel scoring scheme weighted for the relative abundances of the experimentally observed product ions and the frequency of fragmentations occurring at preferential cleavage sites. The identification of these proteins illustrates the potential of this "top-down" protein identification approach to reduce the reliance on condensed-phase chemistries and extensive separations for complex protein mixture analysis.

  7. Structural Studies of a Complex Between Endothelial Nitric Oxide Synthase and Calmodulin at Physiological Calcium Concentration.

    PubMed

    Piazza, Michael; Dieckmann, Thorsten; Guillemette, Joseph Guy

    2016-10-04

    The small acidic protein Calmodulin (CaM) serves as a Ca(2+) sensor and control element for many enzymes including nitric oxide synthase (NOS) enzymes that play major roles in key physiological and pathological processes. CaM binding causes a conformational change in NOS to allow for the electron transfer between the reductase and oxygenase domains through a process that is thought to be highly dynamic. In this report, NMR spectroscopy was used to determine the solution structure of the endothelial NOS (eNOS) peptide in complex with CaM at the lowest Ca(2+) concentration (225 nM) required for CaM to bind to eNOS and corresponds to a physiological elevated Ca2+ level found in mammalian cells. Under these conditions, the CaM-eNOS complex has a Ca(2+)-replete C-terminal lobe bound the eNOS peptide and a Ca(2+) free N-terminal lobe loosely associated to the eNOS peptide. With increasing Ca(2+) concentration, the binding of Ca(2+) by the N-lobe of CaM results in a stronger interaction with the C-terminal region of the eNOS peptide and increased α-helical structure of the peptide that may be part of the mechanism resulting in electron transfer from the FMN to the heme in the oxygenase domain of the enzyme. SPR studies performed under the same conditions show Ca(2+) concentration dependent binding kinetics were consistent with the NMR structural results. This investigation shows that structural studies performed under more physiological relevant conditions provide information on subtle changes in structure that may not be apparent when experiments are performed in excess Ca(2+) concentrations.

  8. [Adiponectin, insulin and glucose concentrations in overweight and obese subjects after a complex carbohydrates (fiber) diet].

    PubMed

    González Rodríguez, Dora Cristina; Solano R, Liseti; González Martínez, Julio César

    2009-09-01

    Adiponectin one of the cytokines secreted by the adipose tissue that regulates the energetic metabolism through glucose and insulin interactions, stimulates the oxidation of fatty acids, reduces the plasmatic triglycerides and improves glucose metabolism by increasing insulin sensibility. Serum concentrations of adiponectin, insulin and glucose were assessed in order to establish association to weight loss after a dietary regime based on consumption of complex carbohydrates (fiber) during six weeks. Overweight and obese subjects (n=56) were studied by anthropometry. Adiponectin and insulin were measured by ELISA and glucose by Colorimetry. Data was analyzed by non parametric tests to compare independent or related samples. 12 men and 44 women, aged 20 to 55 years, 17 overweight and 39 obese were assessed. Adiponectin concentration was significantly low at basal determination in all the subjects (4,47 +/- 1,64); being higher in women (4,62 +/- 1,57 vs 3,93 +/- 1,86 microU/mL in men), while glucose and insulin values were at normal range (82,46 +/-26,51 mg/dL and 14,12 +/- 10,15 microU/mL) respectively with no significant differences for sex. Overweight subjects had significantly higher adiponectin concentrations than obese participants, at all measurements. Dietary regime promoted significant increase in adiponectin concentration at second and sixth week, with a negative correlation to body mass index and gender as they lost body weight.

  9. 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.

  10. Variations in plasma motilin, somatostatin, and pancreatic polypeptide concentrations and the interdigestive myoelectric complex in dog.

    PubMed

    Poitras, P; Lemoyne, M; Tasse, D; Trudel, L; Yamada, T; Taylor, I L

    1985-12-01

    We have looked at the plasma concentrations of motilin, pancreatic polypeptide (PP), and somatostatin (STS) during the various phases of the interdigestive motor complex (IDMC) in dogs. As expected, motilin cyclical increase was always associated with the phase III of the IDMC. Statistical analysis of PP variations revealed a significant rise 10 min before duodenal phase III; however, in individual animals, this relationship was inconsistent. Although a dose-related increase in PP blood levels was induced by administration of synthetic canine motilin (0-200 ng kg-1 iv), fasting plasma levels of PP were not correlated with the concentrations of circulating endogenous motilin. After truncal vagotomy, while motilin release and the intestinal motility pattern remained unaltered, the phase III associated cyclical increases of PP disappeared. Infusion of physiological amounts of PP (1 microgram kg-1 h-1 for 3 h) mimicking the postprandial release failed to reproduce a fed pattern type of intestinal motility and of motilin secretion. No statistical correlation could be established between STS plasma levels and the motor activity of the intestine. STS plasma levels were not correlated with circulating concentrations of motilin and the exogenous administration of physiological doses of synthetic canine motilin failed to modify STS plasma levels. Morphine (200 micrograms kg-1 iv) stimulated only the release of motilin. These data suggest that the role played by circulating concentrations of PP and STS in the control of the IDMC in dog is at most minimal.

  11. In vitro reversal of supratherapeutic rivaroxaban levels with coagulation factor concentrates

    PubMed Central

    Körber, Mareike K.; Langer, Elisabeth; Kaufner, Lutz; Sander, Michael; von Heymann, Christian

    2016-01-01

    Background A bleeding patient undergoing therapy with new oral anticoagulants is every clinician’s nightmare as no specific reversal agent is available yet. This in vitro study investigated the effect of prothrombin complex concentrate (PCC), recombinant activated factor VII (rFVIIa) and activated prothrombin complex concentrate (aPCC) on supratherapeutic rivaroxaban concentrations using standard laboratory parameters (prothrombin time [PT], activated partial thromboplastin time [aPTT] and PT ratio) and thromboelastometry (clotting time [CT]). Materials and methods Blood samples from 10 healthy volunteers were collected and spiked with a supratherapeutic dose of rivaroxaban. Afterwards PCC, rFVIIa and aPCC were added in two doses. The laboratory parameters were measured and thromboelastometry was performed. Results The addition of the reversal agents had the following statistically significant effects (all p<0.01): +25 IU/kg PCC: CT −15 s, aPTT +5 s; +50 IU/kg PCC: aPTT +11 s; +90 μg rFVIIa: CT −141 s; +25 IU/kg aPCC: CT −142 s, aPTT −9 s, PT ratio +14%, PT −10.5 s; +50 IU/kg aPCC: CT −118 s, aPTT −7 s, PT ratio +17%, PT −12.2 s. Discussion rFVIIa and aPCC, but not PCC, appear to shorten coagulation times significantly in standard laboratory and thromboelastometry assays. These results need confirmation through evaluation of these agents in the clinical setting. PMID:27177413

  12. 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.

  13. 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.

  14. Fermentation of high concentrations of maltose by Saccharomyces cerevisiae is limited by the COMPASS methylation complex.

    PubMed

    Houghton-Larsen, Jens; Brandt, Anders

    2006-11-01

    In Saccharomyces cerevisiae, genes encoding maltose permeases and maltases are located in the telomeric regions of different chromosomes. The COMPASS methylation complex, which methylates lysine 4 on histone H3, controls the silencing of telomeric regions. Yeast strains deleted for SWD1, SWD3, SDC1, SET1, BRE2, or SPP1, encoding components of the COMPASS complex, fermented a medium containing 22% maltose with noticeably higher attenuation than did the wild type, resulting in production of up to 29% more ethanol. The least effective strain was spp1. Absence of COMPASS components had no effect on the fermentation of media with 20% glucose, 20% sucrose, or 16% maltose. Deletion of SWD3 resulted in larger amounts of MAL12 transcript, encoding maltase, at the late stages of fermentation of 22% maltose. A similar effect on maltase activity and maltose uptake capability was seen. The lysine 4 residue of histone H3 was trimethylated in wild-type cells at the late stages, while only small amounts of the dimethylated form were detected. Trimethylation and dimethylation of this residue were not detected in strains deleted for SWD1, SWD3, SET1, BRE2, or SDC1. Trimethylated lysine 4 was apparent only at the early stages (48 and 96 h) of fermentation in an spp1 strain. This work indicates that the COMPASS complex represses the expression of maltose utilization genes during the late stages of fermentation of a high concentration of maltose.

  15. 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

  16. Conversion of simulated radioactive pollutant gas concentrations for a complex building array into radiation dose.

    PubMed

    Gallacher, D J; Robins, A G; Hayden, P

    2016-12-01

    Methods used to convert wind tunnel and ADMS concentration field data for a complex building array into effective radiation dose were developed based on simulations of a site in central London. Pollutant source terms were from positron emitting gases released from a cyclotron and clinical PET radiotracer facility. Five years of meteorological data were analysed to determine the probability distribution of wind direction and speed. A hemispherical plume cloud model (both static and moving) was developed which enabled an expression of gamma-ray dose, taking into account build-up factors in air, in terms of analytic functions in this geometry. The standard building wake model is presented, but this is extended and developed in a new model to cover the concentration field in the vicinity of a roof top structure recirculation zone, which is then related to the concentration in the main building wake zone. For all models presented the effective dose was determined from inhalation, positron cloud immersion and gamma ray plume contributions. Results of applying these models for determination of radiation dose for a particular site are presented elsewhere.

  17. An unusual cause of cerebral venous sinus thrombosis: prothrombin G20210A gene mutation.

    PubMed

    Porres-Aguilar, Mateo; Square, Jaime H; Storey, Raul; Rodriguez-Dunn, Simon; Mohamed-Aly, Mohamed S

    2007-09-01

    Cerebral venous sinus thrombosis represents less than 1% of all strokes, being an uncommon entity with a wide spectrum of clinical scenarios. We present a 45-year-old Hispanic female with a history of long-term oral contraceptive use who was diagnosed with cerebral venous sinus thrombosis due to a heterozygous carrier mutation in the prothrombin G20210A gene. The patient was successfully managed with intravenous heparin with favorable clinical results without adverse effects. The prevalence of inherited primary thrombophilia increases with additional risk factors such as the use of oral contraceptives that can trigger or prothrombotic events in any vascular bed. An increased prevalence in the prothrombin G20210 gene mutation has been demonstrated in the Mexican-Mestizo population. Controversy exists regarding therapy of cerebral venous sinus thrombosis; according to experts, heparin remains the cornerstone of therapy with acceptable outcomes. More clinical trials are required to evaluate long-term outcomes in this subgroup of patients.

  18. Activation of prothrombin by two subtilisin-like serine proteases from Acremonium sp.

    PubMed

    Liu, Chunli; Matsushita, Yasuhiko; Shimizu, Kosuke; Makimura, Koichi; Hasumi, Keiji

    2007-06-22

    Two novel subtilisin-like serine proteases (AS-E1 and -E2) that activate prothrombin have been identified in a culture of the fungus Acremonium sp. The enzymes were purified through repeated hydrophobic interaction chromatography. The N-terminal sequences of AS-E1 (34.4 kDa) and AS-E2 (32 kDa) showed high similarity to the internal sequences of two distinct subtilisin-like hypothetical proteins from Chaetomium globosum. Both enzymes proteolytically activated prothrombin to meizothrombin(desF1)-like molecules, while the activation cleavage seemed to occur at a site (Tyr(316)-Ile(317)) that is four residues proximal to the canonical Xa cleavage site (Arg(320)-Ile(321)). Both enzymes inhibited plasma clotting, possibly due to extensive degradation of fibrinogen and production of meizothrombin(desF1)-like molecule.

  19. THE FACTORS OF COAGULATION IN THE EXPERIMENTAL APLASTIC ANEMIA OF BENZOL POISONING, WITH SPECIAL REFERENCE TO THE ORIGIN OF PROTHROMBIN

    PubMed Central

    Hurwitz, S. H.; Drinker, C. K.

    1915-01-01

    1. Subcutaneous injections of benzol in rabbits produce marked destructive changes in the hematopoietic organs, especially in the myeloid tissue. 2. Benzol poisoning registers a change not only in the formed elements of the blood, but also in the factors of coagulation. 3. The circulating prothrombin is considerably reduced in amount and in most instances animals in which such a diminution occurs show aplasia of the bone marrow. 4. The association of extreme aplasia of the marrow without a fatal diminution in the circulating prothrombin suggests one of two possibilities: either other tissues and organs in addition to the bone marrow are concerned with prothrombin formation; or a minimum amount of myeloid tissue suffices to maintain the quantity of prothrombin above a dangerous level. PMID:19867880

  20. Prothrombin G20210A and methylenetetrahydrofolate reductase C677T polymorphisms in peripheral capillary nonperfusion: a case report.

    PubMed

    Wathek, Chaima; Mrad, Meriem; Abdessalem, Nadia Ben; Maalej, Afef; Gritli, Nasreddine; Gabsi, Salem; Rannen, Riadh; Fekih-Mrissa, Najiba

    2015-09-01

    The G20210A mutation in the prothrombin gene is an established risk factor for venous thrombosis. However, there is some controversy as to the role played by this mutation in arterial thrombotic disease. The association of peripheral capillary nonperfusion with prothrombin G20210A mutation has never been reported before. We present the case of 34-year-old man who presented with peripheral capillary nonperfusion. The fundus examination of his right eye revealed an epiretinal membrane, peripheral (mainly temporally) retinal haemorrhages, exudates and microaneurismal alterations of the vascular bed. Fluorescein angiography of his right eye demonstrated an extended area of capillary nonperfusion distal to the microaneurismal lesions. Evaluation revealed mutations of the G20210A prothrombin and MTHFR genes. Screening for hereditary thrombophilia should be considered, regardless of patient age, in patients with peripheral retinal ischemia. The prothrombin G20210A mutation, a genetic risk factor, may be associated with peripheral capillary nonperfusion.

  1. Disruption of Prostate Microvasculature by Combining Microbubble-Enhanced Ultrasound and Prothrombin

    PubMed Central

    Liu, Yongliang; Qiao, Lu; Gao, Wenhong; Zhang, Weiguo; Liu, Zheng

    2016-01-01

    Previous studies have shown a unique method to disrupt tumor vasculature using pulsed, high-pressure amplitude therapeutic ultrasound combined with microbubbles. In this study, we attempted to destroy the prostate vasculature of canine prostates using microbubble-enhanced ultrasound (MEUS) and prothrombin. The prostates of 43 male mongrel canines were surgically exposed. Twenty-two prostates were treated using MEUS (n = 11) or MEUS and prothrombin (PMEUS, n = 11). The other 21 prostates, which were treated using microbubbles (n = 7), ultrasound (n = 7) or prothrombin (n = 7) only, served as the controls. Prothrombin was intravenously infused at 20 IU/kg. MEUS was induced using a therapeutic ultrasound device at a peak negative pressure of 4.47 MPa and a microbubble injection. Contrast-enhanced ultrasound was performed to assess the blood perfusion of the prostates. Then, the prostate tissue was harvested immediately after treatment and at 48 hours later for pathological examination. The contrast-enhanced ultrasound peak value of the prostate decreased significantly from 36.2 ± 5.6 to 27.1 ± 6.3 after treatment in the PMEUS group, but it remained unchanged in the other groups. Histological examination found severe microvascular rupture, hemorrhage and thrombosis in both MEUS- and PMEUS-treated prostates immediately after treatment, while disruption in the PMEUS group was more severe than in the MEUS group. Forty-eight hours after treatment, massive necrosis and infiltration of white blood cells occurred in the PMEUS group. This study demonstrated that PMEUS disrupted the normal microvasculature of canine prostates and induced massive necrosis. PMEUS could potentially become a new noninvasive method used for the treatment of benign prostatic hyperplasia. PMID:27643992

  2. Disparate temporal expression of the prothrombin and thrombin receptor genes during mouse development.

    PubMed Central

    Soifer, S. J.; Peters, K. G.; O'Keefe, J.; Coughlin, S. R.

    1994-01-01

    The protease thrombin is a potent agonist for platelet aggregation, mesenchymal cell proliferation, and endothelial production of growth factors and adhesion molecules. Thrombin also modulates neurite outgrowth in neuronal cultures. These apparently disparate responses to thrombin appear to be largely mediated by the recently cloned thrombin receptor. In the adult, thrombin is generated from its zymogen prothrombin at sites of vascular injury when circulating coagulation factors meet extravascular tissue factor. In this context thrombin's varied actions may mediate responses to wounding. Whether thrombin's actions on cells may also play a role in development is unknown. We examined the expression of thrombin receptor, prothrombin, and tissue factor by in situ hybridization in mouse development. Thrombin receptor mRNA was expressed widely in mesenchymal cell populations during early organogenesis (E9.5) and was particularly abundant in developing heart and blood vessels. Robust receptor expression was also noted in the germinal epithelium of the hindbrain. Thrombin receptor expression became more restricted with time and by the fetal growth stage (E16.5) was most readily detected in certain neurons, endocardial and endothelial cells, and within lung and liver. In contrast to the thrombin receptor, prothrombin mRNA was limited to the embryonic liver and was not detected until E12.5, well after the onset of receptor expression. mRNA for tissue factor, one important trigger for thrombin generation in the adult, was detected in embryonic epithelia from E9.5-12.5. In several instances, tissue factor-expressing epithelia were surrounded by thrombin receptor-expressing mesenchyme. These data suggest a possible role for the thrombin receptor in development. The finding of robust thrombin receptor expression before prothrombin mRNA was detected raises the question of whether other proteases or peptide ligands can activate the thrombin receptor. Images Figure 1 Figure 2

  3. 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.

  4. 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

  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. Peak Plasma Concentration of Azithromycin and Treatment Responses in Mycobacterium avium Complex Lung Disease.

    PubMed

    Jeong, Byeong-Ho; Jeon, Kyeongman; Park, Hye Yun; Moon, Seong Mi; Kim, Su-Young; Lee, Soo-Youn; Shin, Sung Jae; Daley, Charles L; Koh, Won-Jung

    2016-10-01

    Macrolides, such as azithromycin (AZM) and clarithromycin, are the cornerstones of treatment for Mycobacterium avium complex lung disease (MAC-LD). Current guidelines recommend daily therapy with AZM for cavitary MAC-LD and intermittent therapy for noncavitary MAC-LD, but the effectiveness of these regimens has not been thoroughly investigated. This study evaluated associations between microbiological response and estimated peak plasma concentrations (Cmax) of AZM. The AZM Cmax was measured in patients receiving daily therapy (250 mg of AZM daily, n = 77) or intermittent therapy (500 mg of AZM three times weekly, n = 89) for MAC-LD and daily therapy for Mycobacterium abscessus complex LD (MABC-LD) (250 mg of AZM daily, n = 55). The AZM Cmax was lower with the daily regimen for MAC-LD (median, 0.24 μg/ml) than with the intermittent regimen for MAC-LD (median, 0.65 μg/ml; P < 0.001) or daily therapy for MABC-LD (median, 0.53 μg/ml; P < 0.001). After adjusting for confounding factors, AZM Cmax was independently associated with favorable microbiological responses in MAC-LD patients receiving a daily regimen (adjusted odds ratio [aOR], 1.58; 95% confidence interval [CI], 1.01 to 2.48; P = 0.044) but not an intermittent regimen (aOR, 0.85; 95% CI, 0.58 to 1.23, P = 0.379). With the daily AZM-based multidrug regimen for MAC-LD, a low AZM Cmax was common, whereas a higher AZM Cmax was associated with favorable microbiologic responses. The results also suggested that the addition of rifampin may lower AZM Cmax When a daily AZM-based multidrug regimen is used for treating severe MAC-LD, such as cavitary disease, the currently recommended AZM dose might be suboptimal. (This study has been registered at ClinicalTrials.gov under identifier NCT00970801.).

  7. Ground-based microwave complex for remote sounding of middle atmosphere thermal structure and ozone concentration

    NASA Astrophysics Data System (ADS)

    Shvetsov, Alexander; Kulikov, Mikhail; Feigin, Alexander; Karashtin, Dmitry; Krasilnikov, Alexander; Mukhin, Dmitry; Bolshakov, Oleg; Fedoseev, Lev; Ryskin, Vitaly; Belikovich, Michael; Kukin, Lev

    2012-07-01

    Existing methods of remote sensing of the thermal structure of the atmosphere and the ozone layer are based on measurements from space. However, having great advantage in global coverage of the Earth they cannot provide high spatial and temporal resolution, required to study rapidly occurring phenomena. This problem can be solving by ground-based system of remote sounding. For this purpose ground-based microwave complex for remote sensing of middle atmosphere thermal structure and ozone concentration have been developed in the Institute of Applied Physics of the Russian Academy of Sciences. The complex consists of the microwave ozonometer and the stratospheric thermometer. Ozonometer is a heterodyne spectroradiometer, operating in the frequency range that include the rotation transition of ozone molecules 6 _{1.5}-6 _{0.6} with resonance frequency 110.836 GHz. Operating frequency range of the stratospheric thermometer is 52.5-54.5 GHz and includes low frequency edge of 5 mm molecular oxygen absorption bands and some relatively weak lines of O _{2} resolved from the ground. Digital fast Fourier transform spectrometer developed by ``Acqiris'' company is employed for signal spectral analysis on intermediate frequency in both spectroradiometers. The spectrometer has frequency range 0.05-1 GHz and realizes the effective resolution about 61~KHz. Retrieval of the atmospheric temperature and ozone profiles is made on the basis of results of the radiation spectrum measurements. The Bayesian approach method is used for combined retrieval of stratosphere temperature and ozone profiles. This method allows statistically correct inclusion of both the measurement noise and the a priori information on the reconstructed profile needed for regularization of the problem. First simultaneous ground-based measurements of self-radiation of atmospheric ozone and oxygen have been made in January, 2012 during the sudden stratospheric warming above Nizhny Novgorod, Russia. Temperature and

  8. 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.

  9. 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

  10. 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

    2015-10-08

    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.

  11. Prothrombin-activator (thromboplastin) generation in the blood of water snake (Natrix piscator).

    PubMed

    Srivastava, V M; Dube, B; Dube, R K; Agarwal, G P

    1981-12-23

    The generation of prothrombin-activator (thromboplastin) in water snake (Natrix piscator) is clearly delayed, compared to a mammalian system, but the final activity is well comparable to that in man, when homologous sources of "phospholipid" (erythrocyte-lysate) and of substrate plasma are employed in one stage "thromboplastin generation test". The use of heterologous source of either of the above reagents resulted in significantly longer clotting times; hence the need for homologous source of above reagents in the test is emphasized for comparative studies on animal haemostasis.

  12. Impact of telavancin on prothrombin time and activated partial thromboplastin time as determined using point-of-care coagulometers.

    PubMed

    Ero, Michael P; Harvey, Nathaniel R; Harbert, Jack L; Janc, James W; Chin, Kay H; Barriere, Steven L

    2014-01-01

    Telavancin is approved in the United States, Canada, and Europe (At the time of submission, the telavancin European marketing authorization for nosocomial pneumonia was suspended until Theravance provides evidence of a new European Medicines Agency approved supplier) as an antibiotic to treat certain Gram-positive bacterial skin infections. Telavancin has been shown to prolong plasmatic prothrombin (PT) and activated partial thromboplastin (aPTT) clotting times in clinical diagnostic lab-based assays. In this study, we evaluated the potential for telavancin to prolong whole blood PT/International Normalized Ratio (INR) and aPTT tests on point-of-care (POC) instruments. Whole blood collected from 8 healthy subjects was supplemented with telavancin to final concentrations of 0, 10, 20, and 100 μg/ml. Final concentrations were selected to match trough, twice trough, and peak plasma levels following the approved 10 mg/kg dose. Four widely employed POC coagulation instruments were chosen to be representative of the POC platforms currently in use.. These systems were the Roche Coaguchek XS, the Abbott iSTAT, the ITC Hemochron SIG+, and the Alere INRatio2 POC devices. The PT/INR measured by the Coaguchek XS showed the greatest sensitivity to the presence of telavancin. The PT/INR measured by the Hemochron SIG+ and iSTAT were sensitive to telavancin but to a lesser extent. The INRatio2 was the least sensitive to the presence of telavancin when testing the whole blood PT/INR. Only the Hemochron SIG+ device was capable of measuring aPTT and showed a concentration-dependent increase in aPTT. This study supports the current recommendation that PT and aPTT monitoring be conducted immediately to the next dose of telavancin when coagulation parameters are tested using POC instrumentation.

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

    PubMed Central

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

    2016-01-01

    Abstract 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

  14. Thermal isoelectric precipitation of alpha-lactalbumin from a whey protein concentrate: Influence of protein-calcium complexation.

    PubMed

    Bramaud, C; Aimar, P; Daufin, G

    1995-07-20

    The selective precipitation of alpha-lactalbumin (alpha-LA) at a pH around its isoelectric point (4.2) under heat treatment is the basis for a fractionation process of whey proteins. As precipitation is a phenomenon dependent on the protein hydrophobicity, and as the release of the tightly bound calcium occurring at pH around 4 modifies the alpha-LA hydrophobicity, the specific role of calcium on isoelectric precipitation is investigated. A study of the extent of alpha-LA precipitation in a whey protein concentrate under various operating conditions of pH, temperature, protein concentration, and calcium content is presented. We propose a mechanism for this phenomenon as a combination of a complexation equilibrium and of an irreversible precipitation, to account for the influence of temperature, alpha-LA concentration total ionic content, and calcium concentration, and also to estimate the complexation equilibrium constant. (c) 1995 John Wiley & Sons, Inc.

  15. Different outcome of six homozygotes for prothrombin A20210A gene variant

    PubMed Central

    Di Micco, Pierpaolo; Di Fiore, Rosanna; Niglio, Alferio; Quaranta, Sandro; Angiolillo, Antonella; Cardillo, Giuseppe; Castaldo, Giuseppe

    2008-01-01

    Prothrombin G20210A gene variant (FII G20210A) is a risk factor for venous thrombotic disease while conflicting results have been reported for the risk of arterial thrombotic events. However, vascular episodes were absent in up to 40% of the 67 homozygotes for the G20210A described so far, which indicates that the clinical expression depends on additional risk/trigger factors. We describe six homozygotes for the G20210A variant, among which the first pair of siblings (cases n. 3 and 4) reported so far that displayed a strongly heterogeneous clinical outcome. Case 1, a female of 27 years, developed a full thrombosis of common femoral, superficial and popliteal veins. She assumed oral contraceptives in the last two years. Case n. 2, 34 years old, suffered of recurrent pregnancy loss in absence of any causative alteration. Cases n. 3 and n. 5 experienced arterial thrombotic disease, i.e., juvenile myocardial infarction (40 years old) and stroke (48 years old), respectively, in absence of other risk factors. Finally, cases n. 4 and 6 identified as homozygotes for the FII G20210A variant being consanguineous of symptomatic subjects bearing the variant, did not experience any episode of venous nor arterial disease. Both of them have chronic liver disease with an impairement of the prothrombin time INR. Thus, homozygotes for the G20210A are at risk for arterial (in addition to venous) thromobotic events; chronic liver disease might modulate this risk. PMID:18627609

  16. Vascular behcet and mutations in thrombogenic genes: methylene tetrahydrofolate reductase, factor V, and prothrombin.

    PubMed

    Dagan, Efrat; Baruch, Yoav; Fiorilli, Massimo; Rozenbaum, Michael; Rosner, Itzhak; Gershoni-Baruch, Ruth

    2012-01-01

    Vasculitis, thrombophlebitis, arterial aneurysms, and occlusions occur in about 25% of patients with Behçet's disease (BD). The common inherited gene defects, factor V (FV) 1691A (Leiden), methylene tetrahydrofolate reductase (MTHFR) 677T, and prothrombin 20210A, are known risk factors for thrombosis. The aim of the study was to evaluate the contribution of these mutations to thrombosis in Israeli patients with BD. Fifty-four patients with BD (n=54; 27 men and 27 women) underwent clinical and genetic evaluation. Most patients (n=43; 79.6%) were of Arab descent (31 sporadic and 12 familial cases from 4 families), and 11 patients (20.4%) were of Jewish descent (all sporadic cases). The FV Leiden mutation was identified in five patients (9.2%), and eight patients were MTHFR 677TT homozygotes (14.8%). None had the 20210A mutant prothrombin allele. No statistical differences between carriers and noncarriers with regards to demographic and disease manifestations were calculated. Arabs were diagnosed earlier than Jewish patients (25.8±11.6 compared with 37.2±10.7, p=0.01, respectively), but Jewish patients had, respectively, more events of deep vein thrombosis (DVT) compared with Arabs (3 of 11, 27.3% and 3 of 43, 7%, p=0.09). Thrombotic events in our patients with BD were not associated with variations in thrombophilic genes.

  17. Sec1p Binds to Snare Complexes and Concentrates at Sites of Secretion

    PubMed Central

    Carr, Chavela M.; Grote, Eric; Munson, Mary; Hughson, Frederick M.; Novick, Peter J.

    1999-01-01

    Proteins of the Sec1 family have been shown to interact with target-membrane t-SNAREs that are homologous to the neuronal protein syntaxin. We demonstrate that yeast Sec1p coprecipitates not only the syntaxin homologue Ssop, but also the other two exocytic SNAREs (Sec9p and Sncp) in amounts and in proportions characteristic of SNARE complexes in yeast lysates. The interaction between Sec1p and Ssop is limited by the abundance of SNARE complexes present in sec mutants that are defective in either SNARE complex assembly or disassembly. Furthermore, the localization of green fluorescent protein (GFP)-tagged Sec1p coincides with sites of vesicle docking and fusion where SNARE complexes are believed to assemble and function. The proposal that SNARE complexes act as receptors for Sec1p is supported by the mislocalization of GFP-Sec1p in a mutant defective for SNARE complex assembly and by the robust localization of GFP-Sec1p in a mutant that fails to disassemble SNARE complexes. The results presented here place yeast Sec1p at the core of the exocytic fusion machinery, bound to SNARE complexes and localized to sites of secretion. PMID:10427089

  18. Clinical and biochemical characterization of the prothrombin Belgrade mutation in a large Serbian pedigree: new insights into the antithrombin resistance mechanism.

    PubMed

    Miljic, P; Gvozdenov, M; Takagi, Y; Takagi, A; Pruner, I; Dragojevic, M; Tomic, B; Bodrozic, J; Kojima, T; Radojkovic, D; Djordjevic, V

    2017-01-11

    Essentials Prothrombin Belgrade mutation leads to antithrombin resistance. Clinical and biochemical phenotypes in a large family with this mutation were investigated. In carriers, we detected decreased factor II activity and increased endogenous thrombin potential. Prothrombin Belgrade mutation represents a strong prothrombotic risk factor.

  19. 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.

  20. Feasibility of antibody-poly(glutamic acid) complexes: preparation of high-concentration antibody formulations and their pharmaceutical properties.

    PubMed

    Izaki, Shunsuke; Kurinomaru, Takaaki; Maruyama, Takuya; Uchida, Takayuki; Handa, Kenji; Kimoto, Tomoaki; Shiraki, Kentaro

    2015-06-01

    Development of high-concentration antibody formulations for subcutaneous administration remains challenging. Recently, a precipitation-redissolution method was proposed to prepare suspensions or precipitates of salt-dissociable protein-poly(amino acid) complexes. To elucidate the utility of this method for protein therapy, we investigated the feasibility of a precipitation-redissolution method using poly(amino acid) for high-concentration antibody formulation. Omalizumab and adalimumab formulations of 150 mg/mL could be prepared using poly-l-glutamic acid (polyE) from low-concentration stock solutions. Enzyme-linked immunosorbent assay, circular dichroism, and size-exclusion chromatography revealed that the formation of antibody-polyE complex and precipitation-redissolution process did not significantly affect the immunoreactivity or secondary structure of the antibodies. The precipitation-redissolution method was less time-consuming and more effective than lyophilization-redissolution, evaporation-redissolution, and ultrafiltration from the viewpoint of final yield. Scalability was confirmed from 400 μL to 1.0 L. The general toxicity and pharmacokinetic profiles of the antibody-polyE complex formulations were similar to those of conventional antibody formulations. These results suggested that the precipitation-redissolution method using poly(amino acid) has great potential as a concentration method for antibody formulation and medicinal use.

  1. 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.

  2. Painless Livedoid Vasculopathy in a Patient with G20210A Prothrombin Gene Mutation.

    PubMed

    Mirrakhimov, Aibek E; Velasquez Kho, Erwin; Ali, Alaa

    2012-01-01

    87 year old Caucasian female with chronic painless non-healing ulcers over malleoli was admitted to the hospital. On a physical examination, there were two bilateral and laterally located malleoli ulcers with no discharge. A thorough work up was done: lower extremities venous and arterial Doppler ultrasound did not show any evidence of venous and arterial disease respectively. Heterozygous G20210A Prothrombin gene mutation was found, and the patient was started on anticoagulation. This case reports highlights a possibility of a painless livedoid vasculopathy presentation in a patient without significant past thrombotic events. Therefore, it is important to consider livedoid vasculopathy in the differential in a patient with painless ulcerative, atrophic and/or nodular skin lesions over the shins and malleoli.

  3. Association between prothrombin gene polymorphisms and hereditary thrombophilia in Xinjiang Kazakhs population.

    PubMed

    Ge, Xiao-Hu; Zhu, Feng; Wang, Bing-Lin; Wang, Chang-Min; Zhu, Bing; Guan, Sheng; Ci, Hong-Bo; Sai, Li-Mu; Jiang, Xiao-Kui; Ren, Hao; Fang, Qing-Bo; Tian, Guang-Lei

    2014-03-01

    To assess the association between polymorphisms of prothrombin gene and hereditary thrombophilia in Xinjiang Kazakhs population. Through cross-sectional investigation, permanent Kazakh population of Ili Kazakh Autonomous Prefecture was selected as the study object to measure their antithrombin III (AT-III), protein C, protein S activity and activated C protein resistance value, thus defining the situation of the crowd's hereditary thrombophilia. Sequenom Massarray detection technology was used to conduct a genotype test of the six sites selected by the case and control groups. Haploview software was used to perform linkage disequilibrium analysis of the six sites, and the impact of the interaction between genetic variations and environment on hereditary thrombophilia was researched by the use of sum model. A total of 1005 Kazakh volunteers participated in the test (332 men and 673 women), average age (41.13 ± 11.50) years; the prevalence of hereditary thrombophilia in Xinjiang Kazakh population was 31.0%, and the prevalence of AT-III deficiency, protein C deficiency, protein S deficiency and activated protein C resistance was 16.4, 14.9, 20.6 and 7.8%, respectively. The difference in allele frequency of the hereditary thrombophilia patient group at rs3136447 and rs5896 sites was statistically significant (P = 0.0483 and P = 0.0302, respectively). rs5896 and rs2070852 had high linkage disequilibrium (r = 0.99), and constituted a single-domain block 1. The rs3136447 and the rs5896 polymorphisms located in the region of the prothrombin gene may be associated with hereditary thrombophilia in the Xinjiang Kazakhs population. There is additive interactive effect of rs5896 polymorphism (CT + TT) and smoke on hereditary thrombophilia.

  4. Synthesis and reductive elimination of arylPd(ii) trifluoromethyl complexes: a remarkable concentration effect on chemoselectivity.

    PubMed

    Zhang, Song-Lin; Deng, Zhu-Qin

    2016-12-07

    Reductive elimination from Pd(ii) aryl trifluoromethyl complexes is a challenging and elusive step which is accompanied by a number of kinetically more favorable side reactions giving rising to a complex mixture. We report herein the synthesis and isolation of several arylPd(ii) trifluoromethyl complexes (2a-c) and study their electronic structures, photophysical properties and reductive elimination reactivities. A remarkable concentration effect on chemoselectivity is observed for thermal decomposition of (Xantphos)Pd(ii)(Ar)(CF3) (2c) that favors the formation of Ar-CF3 at lower concentrations, but gives increasingly more Ar-Ar homocoupling product to a dominant extent as the concentration of 2c increases. This is solid evidence for the involvement of an intermolecular Ar/CF3 ligand exchange/Ar-Ar reductive elimination mechanism that has been proposed based on DFT computational studies. The interplay between theory and experiment provides valuable insights into the mechanism and kinetics of the key elementary reaction of reductive elimination at Pd(ii), and may thus prompt the design of more efficient Pd-mediated nucleophilic trifluoromethylation reactions.

  5. 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

    2015-06-02

    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.

  6. 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.

  7. 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.

  8. Effect of the Amine Concentration on Phase Evolution and Densification in Printed Films Using Cu(II) Complex Ink.

    PubMed

    Choi, Yun-Hyuk; Hong, Seong-Hyeon

    2015-07-28

    The nucleation and growth behavior of Cu nanoparticles during thermal heating of Cu(II) complex inks for printed Cu metallization were investigated, particularly focusing on the effects of the amine concentration on the microstructure evolution and electrical conductivity. Herein, the dual effects of hexylamine as a reducing agent dissociating the carboxyl group from the precursor and a capping agent hindering the subsequent growth of Cu nuclei were confirmed. On the basis of such dual effects of amine, the sufficient complexation of the Cu(II) precursor with a high amine concentration in the ink led to the single-route growth of Cu nanoparticles during thermal heating, which resulted in the dense film with a narrow particle size distribution exhibiting a high electrical conductivity. The electrical conductivity of the film could be further enhanced by a reducing atmosphere with formic acid. Significantly, the understanding of the ink chemistry and the nucleation and growth kinetics in the metal ion complex or metal-organic decomposition (MOD) ink can provide the design rules for the formulation of the solution-type inks to control the microstructure of printed metallization.

  9. 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.

  10. A review of alcohol-impaired driving: the role of blood alcohol concentration and complexity of the driving task.

    PubMed

    Martin, Teri L; Solbeck, Patricia A M; Mayers, Daryl J; Langille, Robert M; Buczek, Yvona; Pelletier, Marc R

    2013-09-01

    The operation of a motor vehicle requires the integrity of sensory, motor, and intellectual faculties. Impairment of these faculties following the consumption of alcohol has been studied extensively through laboratory, closed-course and on-road driving, and epidemiological studies. The scientific literature was reviewed critically, with a focus on low-to-moderate blood alcohol concentrations (BAC ≤ 0.100%), to identify the most reliable determinants of alcohol-impaired driving. Variables such as age, gender, driving skill, and tolerance were shown to have limited impact on impairment. It was concluded the most relevant variables are BAC and complexity of the driving task. The scientific literature provides a high degree of confidence to support the conclusion that a BAC of 0.050% impairs faculties required in the operation of a motor vehicle. Whether impairment is apparent depends upon the complexity of the driving task, which applies to both study design and actual driving.

  11. 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)

  12. [Recurrent vascular access trombosis associated with the prothrombin mutation G20210A in a adult patient in haemodialysis].

    PubMed

    Quintana, L F; Coll, E; Monteagudo, I; Collado, S; López-Pedret, J; Cases, A

    2005-01-01

    Vascular access-related complications are a frequent cause of morbidity in haemodialysis patients and generate high costs. We present the case of an adult patient with end-stage renal disease and recurrent vascular access thrombosis associated with the prothrombin mutation G20210A and renal graft intolerance. The clinical expression of this heterozygous gene mutation may have been favoured by inflammatory state, frequent in dialysis patients. In this patient, the inflammatory response associated with the renal graft intolerance would have favored the development of recurrent vascular access thrombosis in a adult heterozygous for prothrombin mutation G20210A. In the case of early dysfunction of haemodialysis vascular access and after ruling out technical problems, it is convenient to carry out a screening for thrombophilia.

  13. 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.

  14. 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.

  15. How to report results of prothrombin and activated partial thromboplastin times.

    PubMed

    Tripodi, Armando; Lippi, Giuseppe; Plebani, Mario

    2016-02-01

    Prothrombin time (PT) and activated partial thromboplastin time (APTT) are the most widely used tests to investigate coagulation abnormalities. Varied result reporting have been introduced over the years for the two tests, thus making their interpretation rather confusing in different clinical settings. PT results have been reported as clotting time, percentage activity, PT-ratio (patient-to-normal clotting time) and as international normalized ratio (INR). The INR scale has been devised to harmonize results stemming from different thromboplastins from patients on treatment with vitamin K antagonists. Therefore, there are some theoretical and evidence-based considerations that make the INR formally invalid when the test is used to analyze patients in other clinical settings. Unfortunately, this limitation has been frequently overlooked, and the INR has been (and is currently) used as a universal system of results harmonization. The APTT has been historically reported as clotting time or as ratio (patient-to-normal clotting time). In this opinion paper we review the current state-of-the-art for result reporting and attempt to give practical guidance on how PT and APTT should be reported in different clinical conditions for which the tests are requested.

  16. 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.

  17. 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.

  18. Reference materials (RMs) for analysis of the human factor II (prothrombin) gene G20210A mutation.

    PubMed

    Klein, Christoph L; Márki-Zay, János; Corbisier, Philippe; Gancberg, David; Cooper, Susan; Gemmati, Donato; Halbmayer, Walter-Michael; Kitchen, Steve; Melegh, Béla; Neumaier, Michael; Oldenburg, Johannes; Leibundgut, Elisabeth Oppliger; Reitsma, Pieter H; Rieger, Sandra; Schimmel, Heinz G; Spannagl, Michael; Tordai, Attilia; Tosetto, Alberto; Visvikis, Sophie; Zadro, Renata; Mannhalter, Christine

    2005-01-01

    The Scientific Committee of Molecular Biology Techniques (C-MBT) in Clinical Chemistry of the IFCC has initiated a joint project in co-operation with the European Commission, Joint Research Centre, Institute of Reference Materials and Measurements to develop and produce plasmid-type reference materials (RMs) for the analysis of the human prothrombin gene G20210A mutation. Although DNA tests have a high impact on clinical decision-making and the number of tests performed in diagnostic laboratories is high, issues of quality and quality assurance exist, and currently only a few RMs for clinical genetic testing are available. A gene fragment chosen was produced that spans all primer annealing sites published to date. Both the wild-type and mutant alleles of this gene fragment were cloned into a pUC18 plasmid and two plasmid RMs were produced. In addition, a mixture of both plasmids was produced to mimic the heterozygous genotype. The present study describes the performance of these reference materials in a commutability study, in which they were tested by nine different methods in 13 expert laboratories. This series of plasmid RMs are, to the best of our knowledge, the first plasmid-type clinical genetic RMs introduced worldwide.

  19. Anti-phospholipid antibodies (aPL) and apoptosis: prothrombin-dependent aPL as a paradigm for phospholipid-dependent interactions with apoptotic cells☆

    PubMed Central

    Rauch, Joyce; D’Agnillo, Paolo; Subang, Rebecca; Levine, Jerrold S.

    2012-01-01

    The natural targets of anti-phospholipid antibodies (aPL) and the stimuli that induce them remain unknown. Apoptotic cells have been proposed as both potential targets and immunogens for anti-phospholipid antibodies. Demonstration of selective recognition by anti-phospholipid antibodies provides support for apoptotic cells as antigenic targets. Here, we summarize data showing that prothrombin (PT) binds to apoptotic, but not viable, cells, and that apoptotic-cell bound prothrombin provides a target for human polyclonal and murine monoclonal lupus anticoagulant (LA) antibodies. We discuss findings for two monoclonal lupus anticoagulant antibodies that have high (antibody 29J3-62) or low (antibody 29I4-24) affinity, respectively, for soluble prothrombin. Despite their very different affinities for soluble prothrombin, both monoclonal antibodies reacted similarly with prothrombin bound to phospholipid or apoptotic cells. Furthermore, both antibodies enhanced the binding of prothrombin to apoptotic cells. We propose that the recognition of apoptotic cells by these prothrombin-dependent monoclonal antibodies provides a paradigm for other anti-phospholipid autoantibodies. 29I4-24 is prototypical of phospholipid-dependent anti-phospholipid antibodies, while 29J3-62 represents a prototype for phospholipid-independent anti-phospholipid antibodies. Proteins such as prothrombin and β2-glycoprotein I (β2GPI) bind to apoptotic cells, thereby enhancing the recognition of apoptotic cells by anti-phospholipid antibodies. Furthermore, anti-phospholipid antibodies potentiate the interaction of these proteins with apoptotic cells. While it is unclear whether apoptotic cells are the inducing stimuli in patients with anti-phospholipid antibodies or even whether anti-phospholipid antibodies interact with apoptotic cells in vivo, it is nonetheless clear that anti-phospholipid antibodies have the potential to affect both the procoagulant activity and the uptake and clearance of

  20. Innovative method for the enrichment of high-polarity bioactive molecules present at low concentrations in complex matrices.

    PubMed

    Liu, Qing-Shan; He, Jie; Zhou, Wen-Bin; Gu, Yu-Long; Huang, Huoqiang; Li, Ke-Qin; Yin, Xiao-Ying

    2017-02-01

    Ginsenoside Rg1 is a valuable bioactive molecule but its high polarity and low concentration in complex mixtures makes it a challenge to separate Ginsenoside Rg1 from other saponins with similar structures, resulting in low extraction efficiency. The successful development of effective Rg1 molecularly imprinted polymers that exhibit high selectivity and adsorption may offer an improved method for the enrichment of active compounds. In this work, molecularly imprinted polymers were prepared with two different methods, precipitation polymerization or surface imprinted polymerization. Comparison of the adsorption abilities showed higher adsorption of the surface molecularly imprinted polymers prepared by surface imprinted polymerization, 46.80 mg/g, compared to the 27.74 mg/g observed for the molecularly imprinted polymers prepared by precipitation polymerization. Therefore, for higher adsorption of the highly polar Rg1, surface imprinted polymerization is a superior technique to make Rg1 molecularly imprinted polymers. The prepared surface molecularly imprinted polymers were tested as a solid-phase extraction column to directionally enrich Rg1 and its analogues from ginseng tea and total ginseng extracts. The column with surface molecularly imprinted polymers showed higher enrichment efficiency and better selectivity than a C18 solid-phase extraction column. Overall, a new, innovative method was developed to efficiently enrich high-polarity bioactive molecules present at low concentrations in complex matrices.

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

    DOE PAGES

    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

  2. A complexity measure based method for studying the dependance of 222Rn concentration time series on indoor air temperature and humidity.

    PubMed

    Mihailovic, D T; Udovičić, V; Krmar, M; Arsenić, I

    2014-02-01

    We have suggested a complexity measure based method for studying the dependence of measured (222)Rn concentration time series on indoor air temperature and humidity. This method is based on the Kolmogorov complexity (KL). We have introduced (i) the sequence of the KL, (ii) the Kolmogorov complexity highest value in the sequence (KLM) and (iii) the KL of the product of time series. The noticed loss of the KLM complexity of (222)Rn concentration time series can be attributed to the indoor air humidity that keeps the radon daughters in air.

  3. 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.

  4. 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.

  5. 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

  6. European Concerted Action on Anticoagulation (ECAA). An assessment of lyophilised plasmas for ISI calibration of CoaguChek and TAS whole blood prothrombin time monitors

    PubMed Central

    Poller, L; Keown, M; Chauhan, N; van den Besselaar, A M H P; Tripodi, A; Shiach, C; Jespersen, J

    2003-01-01

    Aims: The recommended method for the international sensitivity index (ISI) calibration of whole blood point of care testing (POCT) prothrombin time (PT) systems was originally described by Tripodi et al in 1993 but is too complex and demanding. The present European Concerted Action on Anticoagulation (ECAA) study aimed to assess the reliability of simpler ISI calibration using lyophilised plasma samples. Methods: ISI calibrations using three different types of ECAA lyophilised plasma samples (artificially depleted, individual, and pooled coumarin) were compared with whole blood calibrations on CoaguChek Mini and TAS PT-NC POCT monitors at 10 centres. Results: With CoaguChek Mini systems, lyophilised coumarin plasma samples (both single donation and pooled) gave ISI and international normalised ratio (INR) values comparable to whole blood. With artificially depleted plasma, ISI and INR values were too high. With TAS PT-NC systems, all three types of lyophilised plasma samples gave inaccurate ISI and unreliable INR results, similar to previous ECAA findings with fresh plasma calibrations. Conclusions: With CoaguChek Mini systems, ISI calibration can be simplified by the use of ECAA lyophilised plasma samples from coumarin treated patients. Further study is needed to devise a simpler calibration method for the TAS PT-NC system. PMID:12560389

  7. Complexity.

    PubMed

    Gómez-Hernández, J Jaime

    2006-01-01

    It is difficult to define complexity in modeling. Complexity is often associated with uncertainty since modeling uncertainty is an intrinsically difficult task. However, modeling uncertainty does not require, necessarily, complex models, in the sense of a model requiring an unmanageable number of degrees of freedom to characterize the aquifer. The relationship between complexity, uncertainty, heterogeneity, and stochastic modeling is not simple. Aquifer models should be able to quantify the uncertainty of their predictions, which can be done using stochastic models that produce heterogeneous realizations of aquifer parameters. This is the type of complexity addressed in this article.

  8. 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.

  9. Dynamics of metal-humate complexation equilibria as revealed by isotope exchange studies - a matter of concentration and time

    NASA Astrophysics Data System (ADS)

    Lippold, Holger; Eidner, Sascha; Kumke, Michael U.; Lippmann-Pipke, Johanna

    2017-01-01

    Complexation with dissolved humic matter can be crucial in controlling the mobility of toxic or radioactive contaminant metals. For speciation and transport modelling, a dynamic equilibrium process is commonly assumed, where association and dissociation run permanently. This is, however, questionable in view of reported observations of a growing resistance to dissociation over time. In this study, the isotope exchange principle was employed to gain direct insight into the dynamics of the complexation equilibrium, including kinetic inertisation phenomena. Terbium(III), an analogue of trivalent actinides, was used as a representative of higher-valent metals. Isotherms of binding to (flocculated) humic acid, determined by means of 160Tb as a radiotracer, were found to be identical regardless of whether the radioisotope was introduced together with the bulk of stable 159Tb or subsequently after pre-equilibration for up to 3 months. Consequently, there is a permanent exchange of free and humic-bound Tb since all available binding sites are occupied in the plateau region of the isotherm. The existence of a dynamic equilibrium was thus evidenced. There was no indication of an inertisation under these experimental conditions. If the small amount of 160Tb was introduced prior to saturation with 159Tb, the expected partial desorption of 160Tb occurred at much lower rates than observed for the equilibration process in the reverse procedure. In addition, the rates decreased with time of pre-equilibration. Inertisation phenomena are thus confined to the stronger sites of humic molecules (occupied at low metal concentrations). Analysing the time-dependent course of isotope exchange according to first-order kinetics indicated that up to 3 years are needed to attain equilibrium. Since, however, metal-humic interaction remains reversible, exchange of metals between humic carriers and mineral surfaces cannot be neglected on the long time scale to be considered in predictive

  10. The Dual Regulatory Role of Amino Acids Leu480 and Gln481 of Prothrombin*

    PubMed Central

    Wiencek, Joesph R.; Hirbawi, Jamila; Yee, Vivien C.; Kalafatis, Michael

    2016-01-01

    Prothrombin (FII) is activated to α-thrombin (IIa) by prothrombinase. Prothrombinase is composed of a catalytic subunit, factor Xa (fXa), and a regulatory subunit, factor Va (fVa), assembled on a membrane surface in the presence of divalent metal ions. We constructed, expressed, and purified several mutated recombinant FII (rFII) molecules within the previously determined fVa-dependent binding site for fXa (amino acid region 473–487 of FII). rFII molecules bearing overlapping deletions within this significant region first established the minimal stretch of amino acids required for the fVa-dependent recognition exosite for fXa in prothrombinase within the amino acid sequence Ser478–Val479–Leu480–Gln481–Val482. Single, double, and triple point mutations within this stretch of rFII allowed for the identification of Leu480 and Gln481 as the two essential amino acids responsible for the enhanced activation of FII by prothrombinase. Unanticipated results demonstrated that although recombinant wild type α-thrombin and rIIaS478A were able to induce clotting and activate factor V and factor VIII with rates similar to the plasma-derived molecule, rIIaSLQ→AAA with mutations S478A/L480A/Q481A was deficient in clotting activity and unable to efficiently activate the pro-cofactors. This molecule was also impaired in protein C activation. Similar results were obtained with rIIaΔSLQ (where rIIaΔSLQ is recombinant human α-thrombin with amino acids Ser478/Leu480/Gln481 deleted). These data provide new evidence demonstrating that amino acid sequence Leu480–Gln481: 1) is crucial for proper recognition of the fVa-dependent site(s) for fXa within prothrombinase on FII, required for efficient initial cleavage of FII at Arg320; and 2) is compulsory for appropriate tethering of fV, fVIII, and protein C required for their timely activation by IIa. PMID:26601957

  11. Mixing tests: diagnostic aides in the investigation of prolonged prothrombin times and activated partial thromboplastin times.

    PubMed

    Kershaw, Geoffrey; Orellana, Daniel

    2013-04-01

    Mixing tests are a relatively simple procedure used in the hemostasis laboratory as a first-line investigation into the cause of an abnormal screening test, typically a prolonged activated partial thromboplastin time and/or a prolonged prothrombin time. The mixing test involves combining the test plasma with normal plasma, then repeating the screening test on the mixture to assess whether the clotting time becomes normal or remains prolonged. The primary purpose of a mixing test is to guide further investigations. When mixing test results "normalize," this suggests the test plasma is deficient in clotting factor(s) and thus specific factor assays can be performed to determine which are reduced. When the mixing test result does not "normalize," this suggests the presence of an inhibitor or other type of interference (e.g., the presence of an anticoagulant such as high-dose heparinoids), and so the laboratory needs to determine if this is a lupus anticoagulant or a specific coagulation factor inhibitor, or another type of inhibitor. Because these follow-up investigations are more costly and time-consuming than the basic screening tests, the appropriate performance and interpretation of mixing tests is advantageous for the laboratory. Moreover, the correct laboratory approach is also clinically relevant, as patient management is ultimately affected, and an incorrect interpretation may lead to inappropriate therapies being established. Components of a mixing test that can influence result interpretation include the sensitivity of the used screening reagents to various factor deficiencies and inhibitors, the source or composition of the normal plasma, and the setting of cutoffs for the formula used in expressing mixing test results. Numerous and differing criteria for mixing test interpretation have been suggested historically, which can lead to confusion as to which approach is the most appropriate. The use of differing criteria will also lead to differing

  12. 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.

  13. Moraxella catarrhalis Macrolide-Resistant Isolates Are Highly Concentrated in Two MLST Clonal Complexes -CCN10 and CC363.

    PubMed

    Liu, Ya-Li; Xiao, Meng; Cheng, Jing-Wei; Xu, He-Ping; Xu, Zhi-Peng; Ye, Sha; Zhang, Wen-Juan; Kudinha, Timothy; Kong, Fanrong; Xu, Ying-Chun

    2017-01-01

    To gain some insights into the molecular evolution of Moraxella catarrhalis macrolide resistance, PCR and sequencing analysis of the 23S rRNA gene, copB typing and multilocus sequence typing (MLST) were performed on 181 M. catarrhalis isolates. The isolates were obtained from children (n = 47) and adults (n = 134) presenting with respiratory disease in the years 2010-2014. Macrolide resistance was highly age-related, and nucleotide position alterations at A2330T could be detected in all macrolide-resistant isolates. copB 0 and copB NT (non-typable) were only found in macrolide-susceptible isolates from adults. Furthermore, copB I/III was the main type in adult or macrolide-susceptible isolates, while copB II was the most common type in children or macrolide-resistant isolates. Twenty-two different MLST clusters (sharing 7 of the 8 identical loci) were detected and only four likely primary founders (ST224, ST363, STN08, and STN10) which belong to clonal complex (CC) 224, CC363, CCN08, and CCN10, were detected, respectively. Macrolide-resistant M. catarrhalis isolates were highly concentrated in two CCs (CCN10 and CC363), which indicates some potential evolutionary advantage or co-evolution to some extent. However, further studies are needed to fully elucidate the evolution of CCN10 and CC363 in macrolide resistance.

  14. Landscape variability of the stable carbon isotope composition of soil CO2 concentrations and flux in complex terrain

    NASA Astrophysics Data System (ADS)

    Riveros-Iregui, Diego; Liang, Liyin; Risk, David

    2015-04-01

    Stable isotopes are commonly used to understand how physical and biological processes mediate the exchange of carbon between terrestrial ecosystems and the atmosphere. Numerous studies have described fundamental relationships between environmental variables, the carbon isotopic composition (δ13C) of recently assimilated sugars in plants, litter, soil carbon, or recently respired CO2. However, studies that examine the landscape scale variability of the 13C content of forest soils are lacking. We report on measurements of the carbon isotopic composition of soil CO2 concentrations (δ13CC) and flux (δ13CJ) across a subalpine forest of the northern Rocky Mountains of Montana, United States. Our analysis demonstrates that soil moisture and the lateral redistribution of soil water are strong predictors of the spatial variability of both δ13CC and δ13CJ at the watershed scale. Our analysis suggests that there are concomitant yet independent effects of soil water on physical (i.e., soil gas diffusivity) and biological (i.e., photosynthetic activity) processes that mediate the 13C composition of forest soils. We show systematic spatial variability in the δ13C of forest soils at the landscape scale that can be useful to accurately predict and model land-atmosphere CO2 exchange over complex terrain.

  15. Moraxella catarrhalis Macrolide-Resistant Isolates Are Highly Concentrated in Two MLST Clonal Complexes -CCN10 and CC363

    PubMed Central

    Liu, Ya-Li; Xiao, Meng; Cheng, Jing-Wei; Xu, He-Ping; Xu, Zhi-Peng; Ye, Sha; Zhang, Wen-Juan; Kudinha, Timothy; Kong, Fanrong; Xu, Ying-Chun

    2017-01-01

    To gain some insights into the molecular evolution of Moraxella catarrhalis macrolide resistance, PCR and sequencing analysis of the 23S rRNA gene, copB typing and multilocus sequence typing (MLST) were performed on 181 M. catarrhalis isolates. The isolates were obtained from children (n = 47) and adults (n = 134) presenting with respiratory disease in the years 2010–2014. Macrolide resistance was highly age-related, and nucleotide position alterations at A2330T could be detected in all macrolide-resistant isolates. copB 0 and copB NT (non-typable) were only found in macrolide-susceptible isolates from adults. Furthermore, copB I/III was the main type in adult or macrolide-susceptible isolates, while copB II was the most common type in children or macrolide-resistant isolates. Twenty-two different MLST clusters (sharing 7 of the 8 identical loci) were detected and only four likely primary founders (ST224, ST363, STN08, and STN10) which belong to clonal complex (CC) 224, CC363, CCN08, and CCN10, were detected, respectively. Macrolide-resistant M. catarrhalis isolates were highly concentrated in two CCs (CCN10 and CC363), which indicates some potential evolutionary advantage or co-evolution to some extent. However, further studies are needed to fully elucidate the evolution of CCN10 and CC363 in macrolide resistance. PMID:28239374

  16. Effects of Buffer Loading for Electrospray Ionization Mass Spectrometry of a Noncovalent Protein Complex that Requires High Concentrations of Essential Salts

    PubMed Central

    Sterling, Harry J.; Batchelor, Joseph D.; Wemmer, David E.; Williams, Evan R.

    2010-01-01

    Electrospray ionization (ESI) mass spectrometry (MS) is a powerful method for analyzing the active forms of macromolecular complexes of biomolecules. However, these solutions often contain high concentrations of salts and/or detergents that adversely effect ESI performance by making ion formation less reproducible, causing severe adduction or ion suppression. Many methods for separating complexes from nonvolatile additives are routinely used with ESI-MS, but these methods may not be appropriate for complexes that require such stabilizers for activity. Here, the effects of buffer loading using concentrations of ammonium acetate ranging from 0.22 to 1.41 M on the ESI mass spectra of a solution containing a domain truncation mutant of a σ54 activator from Aquifex aeolicus were studied. This 44.9 kDa protein requires the presence of millimolar concentrations of Mg2+, BeF3−, and ADP, (at ∼60 °C) to assemble into an active homo-hexamer. Addition of ammonium acetate can improve signal stability and reproducibility, and can significantly lower adduction and background signals. However, at higher concentrations, the relative ion abundance of the hexamer is diminished, while that of the constituent monomer is enhanced. These results are consistent with loss of enzymatic activity as measured by ATP hydrolysis and indicate that the high concentration of ammonium acetate interferes with assembly of the hexamer. This shows that buffer loading with ammonium acetate is effective for obtaining ESI signal for complexes that require high concentrations of essential salts, but can interfere with formation of, and/or destabilize complexes by disrupting crucial electrostatic interactions at high concentration. PMID:20226685

  17. Involvement of the Arp2/3 complex and WASP proteins in the effect of glutoxim and molixan on intracellular Ca(2+) concentration in macrophages.

    PubMed

    Krutetskaya, Z I; Milenina, L S; Naumova, A A; Butov, S N; Antonov, V G; Nozdrachev, A D

    2015-01-01

    The Fura-2AM fluorescent Ca(2+) probe was used to study the possibility that the Arp2/3 complex and WASP proteins are involved in the effects of glutoxim and molixan on the intracellular Ca(2+) concentration in macrophages. It has been demonstrated that preincubation of macrophages with inhibitors of the Arp2/3 complex or WASP proteins (CK-0944666 or wiskostatin, respectively) results in a significant suppression of Ca(2+)-responses induced by glutoxim or molixan. This suggests that polymerization of actin filaments is a process involved in the effect of glutoxim or molixan on intracellular Ca(2+) concentration in macrophages.

  18. 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

  19. Functional properties and active-site topographies of factor X Gla- and prothrombin Gla-domain chimeras of activated protein C.

    PubMed

    Qureshi, Shabir H; Yang, Likui; Manithody, Chandrashekhara; Bae, Jong-Sup; Rezaie, Alireza R

    2008-09-01

    Substitution of the Gla-domain of activated protein C (APC) with the Gla-domain of prothrombin (APC-PTGla) improves the anticoagulant activity of APC independent of protein S. Previous FRET studies showed that this substitution alters the active-site topography of this mutant, rendering it identical to the active site of the APC-protein S complex. In this study, we characterized the functional properties and the active-site topography of another APC chimera containing the Gla-domain of factor X (APC-FXGla). We discovered that the anticoagulant activity of this mutant was similarly improved independent of protein S. The average distance of the closest approach (L) between the donor dye fluorescein attached to the active site of APC derivatives and the acceptor dye octadecylrhodamine incorporated into PC/PS vesicles was determined to be 99 A for APC and 84-86 A for both APC-PTGla and APC-FXGla. Protein S minimally influenced the L values of the APC chimeras, however, it lowered this value to 87 A for wild-type APC. Further studies revealed that neither chimera elicits a protective signaling response in the TNF-alpha-activated endothelial cells. These results suggest that unique structural features within the Gla-domain of APC enable the protease to interact with endothelial protein C receptor in the antiinflammatory pathway, while the same features also cause an inherently lower specific activity for APC in the anticoagulant pathway. This adaptation has made APC a cofactor-dependent protease, requiring the cofactor function of protein S for its optimal anticoagulant function, which appears to involve the alteration of the active-site topography of APC above the membrane surface.

  20. 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

  1. [Cerebral sinovenous thrombosis in a girl with acute lymphoblastic leukaemia carrying the prothrombin G20210A variant].

    PubMed

    González García, H; Sacoto Erazo, G; Moreno Gómez, E; Blanco Quirós, A; Fernández Abril, M C; Alvarez Guisasola, F J

    2013-04-01

    Although cerebral venous thrombosis is rare, it is more commonly associated with children suffering from acute lymphoblastic leukaemia. We report the case of a 7-year-old girl who developed massive cerebral sinovenous thrombosis on day 22 of induction therapy for high-risk acute lymphoblastic leukaemia. Clinical symptoms were gradual onset of headache, decreasing consciousness, and ensuing left hemiplegia. A subsequent prothrombotic study revealed a heterozygous prothrombin G20210A variant in the child and mother. We analysed the prothrombotic factors found in the case before and after thrombosis. We confirm the importance of early exploration of patients for clinical predisposing risk factors of thrombosis and primary prothrombotic states in children with acute lymphoblastic leukaemia. This might help identify patients at particular risk from thrombosis and so administer thromboprophylaxis.

  2. Effect of isotretinoin on prothrombin time (PT), international normalized ratio (INR), and activated partial thromboplastin time (aPTT).

    PubMed

    Kaptanoglu, Asli Feride; Uncu, Murat; Ozyurt, Selcuk; Hincal, Evren

    2013-08-01

    Patients with severe acne may need elective/urgent surgical interventions during treatment with isotretinoin and it is critical for the surgeon to consider the possible effects of this medication on coagulation systems. The aim of this study is to determine the changes in prothrombin time (PT), international normalized ratio (INR), and activated partial thromboplastin time (aPTT) during isotretinoin treatment. PT, aPTT, and INR values of 51 severe acne patients were evaluated during routine pre-treatment biochemical analysis. Only patients with normal values were included in the study. The results of before and after 1 month treatment were compared statistically. There were no statistically significant change in mean alanine aminotranferease (ALT), aspartate aminotransferase (AST), PT, and INR values after treatment. A significant increase in aPTT was detected. The INR values, which are more trusted and safe, showed no difference. Isotretinoin seems to have no effect on these coagulation parameters.

  3. A deep vein thrombosis caused by 20209C>T mutation in homozygosis of the prothrombin gene in a Caucasian patient

    PubMed Central

    Álvarez, Silvia Izquierdo; Ollero, Eva Barrio; Llinares Sanjuan, Francisco Miguel; Martínez, Fabiola Lorente; Calvo Martín, María Teresa

    2014-01-01

    Introduction: Additional nucleotide substitutions in the 3′-untranslated region of prothrombin gene could explain some thrombotic events and also adverse pregnancy outcomes. We describe the first case of a homozygous 20209C>T mutation as the cause of deep vein thrombosis in a Spanish patient. Case and methods: The 56-year-old male patient with a partial tear of the Achilles tendon developed calf (tibial) deep vein thrombosis after immobilization and was treated with an anticoagulant. To determine if the deep vein thrombosis was of genetic origin, a peripheral blood DNA sample was analysed for the presence of the three most frequent mutations associated with thrombotic events: factor V Leiden (1691G>A), prothrombin (20210G>A) and methylene tetrahydrofolate reductase (677C>T). The presence or absence of the normal allele of prothrombin could not be determined using the PTH-FV-MTHFR StripAssay (Vienna Lab). Results: Comprehensive analysis showed that the patient had a variant interfering with the polymerase chain reaction product, we sequenced the entire prothrombin gene and found that the patient had a homozygous C>T mutation at position 20209; this interfered with the polymerase chain reaction product, which needs a C at this position to be able to bind to the wild-type probe present in the test strip. Conclusion: The homozygous 20209C>T mutation and the presence of the mutation 677C>T in heterozygosity explained the patient’s deep vein thrombosis because the combination of mutations would increase the risk of thrombosis. Suitable genetic counselling should be provided to the patient and first-degree relatives as it important to detect prothrombin gene variants that could increase risk for thrombotic events. PMID:24627725

  4. Complex Processing of a Titanium Magnetite Concentrate with Receiving the Products Containing Iron, The Titan and Vanadium

    NASA Astrophysics Data System (ADS)

    Naimanbayev, Madali; Dzurkanov, Zhantore; Lokhova, Nina; Maldybayev, Galymjan

    2016-10-01

    Present study determines conditions for titanium magnetite concentrate processing with fairly complete titanium conversion to the slag and iron and vanadium separation in the hot metal. It is quite difficult to process titanium magnetite concentrate in the blast furnaces due to low fusibility of charge and direct electrical melting which cause process instability. Present work is devoted to development of concentrate double stage smelting process with little soda additions, including solid-phase recovery at the first stage using specific coke as a reductant, avoiding concentrate oxidation and including its preliminary thermooxidation. Mix charge made of concentrate, soda and specific coke was granulated in water, dried at 130°C, pellets were placed in graphite crucible, and later on it was set up in the centre of the furnace in alundum crucible. Temperature regimen was fixed under following parameters: temperature at the first stage was 1250°C soaking time was 50 min; temperature at the second stage was 1500 - 1650°C soaking time was 35 min. It is established that little soda additive (estimated 3-4% Na2O) to the charge of titanium magnetite concentrate recovery smelting behaves as a coagulant during briquetting, as a catalyst in course of solid-phase recovery, as an inhibitor of DRI briquettes secondary oxidation as slag thinner during smelting. In course of titanium magnetite concentrate reduction smelting process, soda interacts to SiO2, AhO3, TiO2 oxides forming sodium silicates and titanates. Double-stage technology of titanium magnetite concentrate reduction smelting was used, both with soda addition, and without oxidation and preliminary iron oxidation of titanium magnetite concentrates till hematite was developed. Optimal process parameters were determined. Following parameters were obtained: hot metal yield was ∼⃒55% of concentrate weight, slag yield - 23.3-25.8%, carbon-free slag content, wt.%: Fe=1.0-1.6; TiO2=62.7-61.9. TiO2 yield in the slag was

  5. Colloids and organic matter complexation control trace metal concentration-discharge relationships in Marshall Gulch stream waters

    NASA Astrophysics Data System (ADS)

    Trostle, Kyle D.; Ray Runyon, J.; Pohlmann, Michael A.; Redfield, Shelby E.; Pelletier, Jon; McIntosh, Jennifer; Chorover, Jon

    2016-10-01

    This study combined concentration-discharge analyses (filtration at 0.45 μm), cascade filtrations (at 1.2, 0.4, and 0.025 μm) and asymmetrical flow field flow fractionation (AF4) to probe the influence of colloidal carriers (dissolved organic matter and inorganic nanoparticles) on observed concentration-discharge relationships for trace metals in a 155 ha forested catchment of the Santa Catalina Mountains Critical Zone Observatory (SCM CZO), Arizona. Many major elements (Na, Mg, Si, K, Ca) show no colloidal influence, and concentration-discharge relationships for these species are explained by previous work. However, the majority of trace metals (Al, Ti, V, Mn, Fe, Cu, Y, REE, U) show at least some influence of colloids on chemistry when filtered at the standard 0.45 μm cutoff. Concentration-discharge slopes of trace metals with modest colloidal influence are shallow (˜0.3) similar to that measured for dissolved organic carbon (DOC, 0.24), whereas elements with greater colloidal influence have steeper concentration-discharge slopes approaching that of Al (0.76), the element with the largest colloidal influence in this study (on average 68%). These findings are further supported by AF4 measurements that show distinct and resolvable pools of low hydrodynamic diameter DOC-sized material coexistent with larger diameter inorganic colloids, and the ratio of these carriers changes systematically with discharge because the DOC pool has a concentration-discharge relationship with shallower slope than the inorganic colloidal pool. Together these data sets illustrate that positive concentration-discharge slopes of trace metals in stream waters may be explained as the relative partitioning of trace metals between DOC and inorganic colloids, with contributions of the latter likely increasing as a result of increased prevalence of macropore flow.

  6. High internal phase emulsions stabilized solely by whey protein isolate-low methoxyl pectin complexes: effect of pH and polymer concentration.

    PubMed

    Wijaya, Wahyu; Van der Meeren, Paul; Wijaya, Christofora Hanny; Patel, Ashok R

    2017-02-22

    In recent years, there has been significant progress in edible emulsion technology especially with respect to creating and stabilizing surfactant-free emulsion systems for food applications. In this paper, we demonstrate the fabrication of high internal phase emulsions (HIPE) (φoil = 0.82) stabilized using colloidal complexes of non-gelling biopolymers (at concentrations as low as 0.3 wt%). The colloidal complexes were pre-formed by combining whey protein isolate (WPI) and low-methoxyl pectin (LMP) at three different pH values (i.e. pH 3.5, 4.5, 5.5) and used further for fabricating stable HIPEs. In addition to the effect of pH, the influence of total biopolymer concentration on the formation and properties of HIPEs was also evaluated. Depending on the total concentration of biopolymers used, the WPI-LMP complexes (formed at pH 4.5) showed a Z-average diameter in the range of 250-350 nm. It was found that the formation of HIPEs was strongly influenced by the pH of the colloidal complexes. At a pH close to the isoelectric point of WPI (≈pH 4.8) and WPI-LMP complexes (≈pH 3.4), severe aggregation of colloidal particles occurred, resulting in poor formation and stability of HIPEs. On comparing the stabilization behaviour of the complexes with the uncomplexed protein, it was noticed that the former provided comparatively better stabilization to the HIPEs against coalescence at pH 4.5 and 5.5. Based on the rheological data (low amplitude oscillatory shear rheology and flow measurements), all HIPE samples showed viscoelastic and shear-thinning behaviour. We believe that such viscoelastic gel-like systems could find potential commercial applications in the development of label-friendly novel food products with interesting textures.

  7. Determining the Concentration Dependent Transformations of Ag Nanoparticles in Complex Media: Using SP-ICP-MS and Au@Ag Core-Shell Nanoparticles as Tracers.

    PubMed

    Merrifield, Ruth C; Stephan, Chady; Lead, Jamie

    2017-03-01

    The fate, behavior, and impact of engineered nanoparticles (NPs) in toxicological and environmental media are driven by complex processes which are difficult to quantify. A key limitation is the ability to perform measurements at low and environmentally relevant concentrations, since concentration may be a key factor determining fate and effects. Here, we use single particle inductively coupled mass spectroscopy (SP-ICP-MS) to measure directly NP diameter and particle number concentration of suspensions containing gold-silver core-shell (Au@Ag) NPs in EPA moderately hard water (MHW) and MHW containing 2.5 mg L(-1) Suwannee River fulvic acid. The Au core of the Au@Ag NPs acts as an internal standard, and aids in the analysis of the complex Ag transformations. The high sensitivity of SP-ICP-MS, along with the Au@Ag NPs, enabled us to track the NP transformations in the range 0.01 and 50 μg L(-1), without further sample preparation. On the basis of the analysis of both Au and Ag parameters (size, size distribution, and particle number), concentration was shown to be a key factor in NP behavior. At higher concentration, NPs were in an aggregation-dominated regime, while at the lower and environmentally representative concentrations, dissolution of Ag was dominant and aggregation was negligible. In addition, further formation of ionic silver as Ag NPs in the form of AgS or AgCl was shown to occur. Between 1 and 10 μg L(-1), both aggregation and dissolution were important. The results suggest that, under realistic conditions, the role of NP homoaggregation may be minimal. In addition, the complexity of exposure and dose in dose-response relationships is highlighted.

  8. 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

  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. 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).

  11. On-line concentration of neutral analytes by complexation and acetonitrile sweeping in nonionic microemulsion electrokinetic chromatography with direct ultraviolet detection.

    PubMed

    Cao, Jun; Yi, Ling; Li, Ping; Chang, Yan-Xu

    2009-07-17

    To separate and detect neutral solutes in nonionic microemulsion electrokinetic chromatography (MEEKC), a novel method was developed, combining complex formation and acetonitrile (ACN) sweeping. In this report, dynamic borate complexation and on-line sweeping occurred simultaneously during a run. The operating parameters which affected the performance of analyte sweeping in nonionic MEEKC were examined in terms of borate complexation, ACN content, Brij-35 concentration and sample plug length. In addition, the validation of the method included tests of the limit of detection, reproducibility and sensitivity enhancement. 60-110-Fold of magnitude improvement in detection sensitivity for model compounds (ginsenoside Rf, ginsenoside Rb2, ginsenoside Re) using Brij-35 microemulsion was demonstrated. Furthermore, the method was applied to the determination of glucosides in the plant extract.

  12. The copper-nickel concentration log: A tool for stratigraphic interpretation within the ultramafic and basal zones of the stillwater complex, Montana

    USGS Publications Warehouse

    Drew, L.J.; Bawiec, W.J.; Page, N.J.; Schuenemeyer, J.H.

    1985-01-01

    An analogue to the electric well log was devised for copper-nickel concentration drill-hole data from the Basal and lower part of the Ultramafic zones of the Stillwater Complex using automated data processing. The copper-nickel concentration logs graphically represent intensity (concentration) values that reflect the distribution of the elements in sulfide and silicate minerals. Four major patterns are recognized by their characteristic variations in copper and nickel intensity: (1) relatively flat, low-level copper-intensity signatures associated with arcuate nickel-intensity patterns that correlate with rocks in the Peridotite member of the Ultramafic zone; (2) arcuate or bulb-like patterns of copper and nickel intensity that correlate closely with the Basal bronzite cumulate member of the Basal zone; (3) complex patterns consisting of intervals of low-intensity copper and moderate-intensity nickel, spikes of high nickel and copper intensity, and high copper intensity associated with low nickel intensity that correlate respectively with cordierite-pyroxene hornfels, massive sulfide, norites and mineralized diabase dikes in the Basal norite member; and (4) large intervals of extremely low copper and nickel intensity that correlate with quartz-orthopyroxene hornfels. The recognition and interpretation of these patterns allow two- and three-dimensional stratigraphic and lithologic reconstructions to be done by means of concentration-log correlations instead of variable quality lithologic logging. ?? 1985.

  13. Combined heterozygosity of factor V leiden and the G20210A prothrombin gene mutation in a patient with cerebral cortical vein thrombosis.

    PubMed

    Liu, X Y; Gabig, T G; Bang, N U

    2000-07-01

    Cerebral venous thrombosis (CVT) is a rare type of stroke with a variety of causes. Several reports have suggested that either factor V Leiden or G20210A prothrombin gene mutation is associated with an increased risk of CVT. The genetic thrombophilias are typically associated with other predisposing factors. We report a unique case of CVT in a patient with both the factor V Leiden and the G20210A prothrombin gene mutations without other identifiable precipitating factors in a 28-year-old white male in good health. MRI and cerebral arterial angiography showed cerebral cortical venous thrombosis. This case suggests that combined heterozygous individuals may be particularly prone to spontaneous thrombosis, like CVT.

  14. Interactions between complicated flow-dispersion patterns and boundary layer evolution in a mountainous complex terrain during elevated SO2 concentrations

    NASA Astrophysics Data System (ADS)

    Matthaios, Vasileios N.; Triantafyllou, Athanassios G.; Garas, Stylianos; Krestou, Athina; Leivaditou, Elena

    2016-11-01

    The dispersion of air pollutants from multiple industrial stacks located in complex topography is an interesting subject. An attractive case is that of the wider region of Western Macedonia in NW Greece, where the greater amount of electric power of Greece is being produced by lignite power plant stations (LPPS). Considerable amounts of atmospheric pollutants are emitted by those LPPS into the atmosphere due to the quantities of coal burned. The variability of the topographic features and the terrain complexity of the area may lead to the formation of local atmospheric circulations of various types, which affect pollutant's transport and dispersion. In the present work, the dispersion conditions that favor the pollutants accumulation in the area are investigated. For this purpose, 1 year's hourly SO2 concentrations, surface wind measurements and a mesoscale meteorological and air pollution model (The Air Pollution Model, TAPM) were used. The SO2 and wind measurements were collected in situ from monitoring stations located nearby and at a greater distance from the power plants. Yearly and daily variations of SO2 concentrations are analyzed and discussed, and the period with the highest concentrations is selected. During this period, the evolution of the atmospheric boundary layer (ABL) in the area as well as the pollutants dispersion is examined. Statistical measures between modeled and observed meteorological data were in good agreement and a good correlation coefficient 0.68 and 0.98 was found in the SO2 variations. The analysis of the wind fields indicated better ventilation in the center of the area due to topographic venturi effects, while the dispersion mechanism which resulted in the relatively high ground level concentrations was fumigation. Finally, the evolution of the ABL was affected by the complex interactions between topography and mesoscale flows as it was found by the turbulent kinetic energy cross sections.

  15. The Complexity of Enzymic Control of Hydrogen Peroxide Concentration May Affect the Regeneration Potential of Plant Protoplasts.

    PubMed Central

    De Marco, A.; Roubelakis-Angelakis, K. A.

    1996-01-01

    Total peroxidase, NADH-peroxidase, ascorbate peroxidase, superoxide dismutase, and catalase activities were measured in tobacco (Nicotiana tabacum) leaves and in regenerating and nonregenerating protoplasts isolated from the same tissue and cultured for 2 weeks. The specific ranges of H2O2 concentration at which the enzymes scavenging the active forms of oxygen may efficiently operate and the activities of those enzymes were determined in an extract from tobacco leaves and in dividing and nondividing tobacco mesophyll protoplasts. The overall H2O2-scavenging enzyme activities were similar in both protoplast populations during the 2 to 3 d of culture. After 3 d, the regenerating protoplasts started to divide and both the antioxidant enzyme activities and the total peroxidase activity increased; in contrast, the viability and the H2O2-scavenging enzyme activities in nonregenerating protoplasts dramatically decreased. Surprisingly, the regenerative potentiality in dividing protoplasts was specifically correlated with a higher NADH-peroxidase activity, which resulted in a net H2O2 accumulation in the cells. Light, which causes the accumulation of active forms of oxygen in photosynthetic organelles, also stimulated catalase and ascorbate peroxidase activities in dividing protoplasts. We suggest that the localization of H2O2 rather than its absolute concentration might be responsible for oxidative stress and that controlled amounts of H2O2 are necessary to allow proper cell-wall reconstitution and the consequent cell division. PMID:12226176

  16. Clinical use of the activated partial thromboplastin time and prothrombin time for screening: a review of the literature and current guidelines for testing.

    PubMed

    Levy, Jerrold H; Szlam, Fania; Wolberg, Alisa S; Winkler, Anne

    2014-09-01

    Although the activated partial thromboplastin time, prothrombin time, and international normalized ratio are widely used in routine preoperative testing, these hemostatic tests are not reliable predictors of perioperative bleeding in patients without known bleeding risk factors. In contrast, a preoperative bleeding history and physical examination are usually obtained in an attempt to identify important bleeding risk factors. However, these coagulation tests are used extensively for monitoring anticoagulation with different pharmacologic agents.

  17. 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.

  18. Evaluation of prothrombin time and activated partial thromboplastin time in hypertensive patients attending a tertiary hospital in calabar, Nigeria.

    PubMed

    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.

  19. Evaluation of prothrombin time and activated partial thromboplastin time mixing studies using an estimated factor correction method.

    PubMed

    Chen, Jian; Phillips, Bonnie; Chandler, Wayne L

    2016-01-01

    Mixing studies for prolonged prothrombin time (PT)/activated partial thromboplastin time (aPTT) are used to estimate whether the prolongation is due to an inhibitor or factor deficiency. We propose a new method of mixing study interpretation based on estimation of average factor level changes. Factor level vs. PT/aPTT curves were prepared for single factor, vitamin K-dependent factor, and all factor deficiencies. These curves were used to predict the factor level in the sample and the correction needed to differentiate deficiencies from inhibitors. We compared this estimated factor correction (EFC) method to normal range, percentage correction, and Rosner index. For a given factor level, multiple factor deficiencies prolonged the PT/aPTT more than single factor deficiency, necessitating different thresholds for defining correction on mixing studies. The EFC method was superior to other the correction methods, correctly identifying 38 of 39 known inhibitors, single and multiple factor deficiencies, and correctly identifying inhibitor vs. deficiency in 50 of 59 patient samples. In 99 adult patient mixing studies over 18 months, 30% showed deficiency only, 30% inhibitor only, whereas 40% showed evidence of both. The EFC method for PT/aPTT mixing study interpretation was more accurate than the comparison methods at determining deficiency versus inhibitor.

  20. Clinically relevant differences in prothrombin time and INR values related to blood sample collection in plastic vs glass tubes.

    PubMed

    Fiebig, Eberhard W; Etzell, Joan E; Ng, Valerie L

    2005-12-01

    We compared prothrombin times (PTs) and international normalized ratios (INRs) for blood samples drawn into plastic vs glass collection tubes. We collected 60 venous blood samples into 4.5-mL glass and 2 plastic tubes (2.7 and 3.5 mL). An additional 153 samples, including 63 from warfarin-anticoagulated patients, were collected only in glass and 2.7-mL plastic tubes. The PTs and INRs were determined following routine laboratory procedures. A subset of 35 frozen aliquot samples was analyzed with a different instrument-reagent combination. The PTs and INRs for samples in plastic tubes were significantly lower than for samples in glass tubes. The mean INR differences increased with INR magnitude from approximately -0.1 (INR, 1.5) to -0.7 (INR, 4.5). Of the plastic tube INRs, 50% were more than 10% lower than INRs from samples collected in glass tubes. Therapeutic monitoring based on plastic-tube INRs could result in higher doses of warfarin.

  1. 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.

  2. Spatial and seasonal variabilities of the stable carbon isotope composition of soil CO2 concentration and flux in complex terrain

    NASA Astrophysics Data System (ADS)

    Liang, Liyin L.; Riveros-Iregui, Diego A.; Risk, David A.

    2016-09-01

    Biogeochemical processes driving the spatial variability of soil CO2 production and flux are well studied, but little is known about the variability in the spatial distribution of the stable carbon isotopes that make up soil CO2, particularly in complex terrain. Spatial differences in stable isotopes of soil CO2 could indicate fundamental differences in isotopic fractionation at the landscape level and may be useful to inform modeling of carbon cycling over large areas. We measured the spatial and seasonal variabilities of the δ13C of soil CO2 (δS) and the δ13C of soil CO2 flux (δP) in a subalpine forest ecosystem located in the Rocky Mountains of Montana. We found consistently more isotopically depleted values of δS and δP in low and wet areas of the landscape relative to steep and dry areas. Our results suggest that the spatial patterns of δS and δP are strongly mediated by soil water and soil respiration rate. More interestingly, our analysis revealed different temporal trends in δP across the landscape; in high landscape positions δP became more positive, whereas in low landscape positions δP became more negative with time. These trends might be the result of differential dynamics in the seasonality of soil moisture and its effects on soil CO2 production and flux. Our results suggest concomitant yet independent effects of water on physical (soil gas diffusivity) and biological (photosynthetic discrimination) processes that mediate δS and δP and are important when evaluating the δ13C of CO2 exchanged between soils and the atmosphere in complex terrain.

  3. Molar Absorptivity and Concentration-Dependent Quantum Yield of Fe(II) Photo-Formation for the Aqueous Solutions of Fe(III)-Dicarboxylate Complexes

    NASA Astrophysics Data System (ADS)

    Hitomi, Y.; Arakaki, T.

    2009-12-01

    Redox cycles of iron in the aquatic environment affect formation of reactive oxygen species such as hydrogen peroxide and hydroxyl radicals, which in turn determines lifetimes of many organic compounds. Although aqueous Fe(III)-dicarboxylate complexes are considered to be important sources of photo-formed Fe(II), molar absorptivity and quantum yield of Fe(II) formation for individual species are not well understood. We initiated a study to characterize Fe(II) photo-formation from Fe(III)-dicarboxylates with the concentration ranges that are relevant to the natural aquatic environment. The Visual MINTEQ computer program was used to calculate the equilibrium concentrations of individual Fe(III)-dicarboxylate species. The molar absorptivity of Fe(III)-dicarboxylate species was obtained by UV-VIS spectrophotometer, and the product of the quantum yield and the molar absorptivity of Fe(III)-dicarboxylate species were obtained from photochemical experiments. These experimental data were combined with the calculated equilibrium Fe(III)-dicarboxylate concentrations to determine individual molar absorptivity and quantum yield of Fe(II) photo-formation for a specific Fe(III)-dicarboxylate species. We used initial concentrations of less than 10 micromolar Fe(III) to study the photochemical formation of Fe(II). Dicarboxylate compounds studied include oxalate, malonate, succinate, malate, and phthalate. We report molar absorptivity and concentration-dependent quantum yields of Fe(II) photo-formation of individual Fe(III)-dicarboxylates.

  4. The frequency of factor V Leiden and prothrombin G20210A mutations in Slovak and Roma (Gypsy) ethnic group of Eastern Slovakia.

    PubMed

    Bôžiková, Alexandra; Gabriková, Dana; Sovičová, Adriana; Behulová, Regina; Mačeková, Soňa; Boroňová, Iveta; Petrejčíková, Eva; Soták, Miroslav; Bernasovská, Jarmila; Bernasovský, Ivan

    2012-10-01

    Factor V Leiden and prothrombin G20210A are the two most prevalent causes of inherited thrombophilia. The prevalence of these mutations varies widely in healthy Caucasian population. The aim of our study was to determine the frequency of factor V Leiden and prothrombin G20210A mutations in Slovak and Roma ethnic group from Eastern Slovakia. We analyzed 540 asymptomatic individuals (269 individuals of Slovak ethnicity and 271 individuals of Roma ethnicity) by real-time PCR method. The detected allele frequencies were 2.97 versus 6.64 % for factor V Leiden (p = 0.0049), and 0.74 versus 0.92 % for prothrombin mutation (p = 0.7463) in Slovak and Roma population, respectively. The Roma ethnic group had significantly higher prevalence of factor V Leiden mutation when compared to Slovak ethnic group. The allele frequency of factor V Leiden in ethnic Romanies from Eastern Slovakia was one of the highest in Europe. Our results confirm an uneven geographical and ethnic distribution of factor V Leiden.

  5. Monitoring of complex industrial bioprocesses for metabolite concentrations using modern spectroscopies and machine learning: application to gibberellic acid production.

    PubMed

    McGovern, Aoife C; Broadhurst, David; Taylor, Janet; Kaderbhai, Naheed; Winson, Michael K; Small, David A; Rowland, Jem J; Kell, Douglas B; Goodacre, Royston

    2002-06-05

    Two rapid vibrational spectroscopic approaches (diffuse reflectance-absorbance Fourier transform infrared [FT-IR] and dispersive Raman spectroscopy), and one mass spectrometric method based on in vacuo Curie-point pyrolysis (PyMS), were investigated in this study. A diverse range of unprocessed, industrial fed-batch fermentation broths containing the fungus Gibberella fujikuroi producing the natural product gibberellic acid, were analyzed directly without a priori chromatographic separation. Partial least squares regression (PLSR) and artificial neural networks (ANNs) were applied to all of the information-rich spectra obtained by each of the methods to obtain quantitative information on the gibberellic acid titer. These estimates were of good precision, and the typical root-mean-square error for predictions of concentrations in an independent test set was <10% over a very wide titer range from 0 to 4925 ppm. However, although PLSR and ANNs are very powerful techniques they are often described as "black box" methods because the information they use to construct the calibration model is largely inaccessible. Therefore, a variety of novel evolutionary computation-based methods, including genetic algorithms and genetic programming, were used to produce models that allowed the determination of those input variables that contributed most to the models formed, and to observe that these models were predominantly based on the concentration of gibberellic acid itself. This is the first time that these three modern analytical spectroscopies, in combination with advanced chemometric data analysis, have been compared for their ability to analyze a real commercial bioprocess. The results demonstrate unequivocally that all methods provide very rapid and accurate estimates of the progress of industrial fermentations, and indicate that, of the three methods studied, Raman spectroscopy is the ideal bioprocess monitoring method because it can be adapted for on-line analysis.

  6. Concentration of copper and a copper-EDTA complex at the pH junction formed in soil by an electrokinetic remediation process.

    PubMed

    Kimura, Tomoyuki; Takase, Ken-Ichi; Tanaka, Shunitz

    2007-05-17

    The formation and stability of a pH junction was investigated, and the precipitation and accumulation of a metal hydroxide at the pH junction was confirmed. Moreover, the possibility that metal ions could be accumulated as a Me-EDTA complex at the pH junction was demonstrated. As a result, the pH junction where the acidic and alkali fronts of soil meet and the pH of soil changes rapidly, appeared at the 0.6 position in the EK process for 6-12 h. Copper ions accumulated in the form of copper hydroxide. EDTA was also concentrated in the position, in general agreement with the position of the pH junction. In addition to copper hydroxide, a copper-EDTA complex was concentrated at the 0.6 position from the anode after EK treatment for 12 h. The copper-EDTA complex was retained in 0.7 position from the anode after 12 h and, after 24 h, the position shifted to 0.8-0.9 from the anode. The possibility of accumulating metal ions within a narrow area, such as a pH junction was demonstrated.

  7. VLA-4 integrin concentrates at the peripheral supramolecular activation complex of the immune synapse and drives T helper 1 responses

    NASA Astrophysics Data System (ADS)

    Mittelbrunn, María; Molina, Ana; Escribese, María M.; Yáñez-Mó, María; Escudero, Ester; Ursa, Ángeles; Tejedor, Reyes; Mampaso, Francisco; Sánchez-Madrid, Francisco

    2004-07-01

    The integrin 41 (VLA-4) not only mediates the adhesion and transendothelial migration of leukocytes, but also provides costimulatory signals that contribute to the activation of T lymphocytes. However, the behavior of 41 during the formation of the immune synapse is currently unknown. Here, we show that 41 is recruited to both human and murine antigen-dependent immune synapses, when the antigen-presenting cell is a B lymphocyte or a dendritic cell, colocalizing with LFA-1 at the peripheral supramolecular activation complex. However, when conjugates are formed in the presence of anti-4 antibodies, VLA-4 colocalizes with the CD3- chain at the center of the synapse. In addition, antibody engagement of 4 integrin promotes polarization toward a T helper 1 (Th1) response in human in vitro models of CD4+ T cell differentiation and naïve T cell priming by dendritic cells. The in vivo administration of anti-4 integrin antibodies also induces an immune deviation to Th1 response that dampens a Th2-driven autoimmune nephritis in Brown Norway rats. These data reveal a regulatory role of 4 integrins on T lymphocyte-antigen presenting cell cognate immune interactions.

  8. VLA-4 integrin concentrates at the peripheral supramolecular activation complex of the immune synapse and drives T helper 1 responses.

    PubMed

    Mittelbrunn, María; Molina, Ana; Escribese, María M; Yáñez-Mó, María; Escudero, Ester; Ursa, Angeles; Tejedor, Reyes; Mampaso, Francisco; Sánchez-Madrid, Francisco

    2004-07-27

    The integrin alpha 4 beta 1 (VLA-4) not only mediates the adhesion and transendothelial migration of leukocytes, but also provides costimulatory signals that contribute to the activation of T lymphocytes. However, the behavior of alpha 4 beta 1 during the formation of the immune synapse is currently unknown. Here, we show that alpha 4 beta 1 is recruited to both human and murine antigen-dependent immune synapses, when the antigen-presenting cell is a B lymphocyte or a dendritic cell, colocalizing with LFA-1 at the peripheral supramolecular activation complex. However, when conjugates are formed in the presence of anti-alpha 4 antibodies, VLA-4 colocalizes with the CD3-zeta chain at the center of the synapse. In addition, antibody engagement of alpha 4 integrin promotes polarization toward a T helper 1 (Th1) response in human in vitro models of CD4(+) T cell differentiation and naïve T cell priming by dendritic cells. The in vivo administration of anti-alpha 4 integrin antibodies also induces an immune deviation to Th1 response that dampens a Th2-driven autoimmune nephritis in Brown Norway rats. These data reveal a regulatory role of alpha 4 integrins on T lymphocyte-antigen presenting cell cognate immune interactions.

  9. 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

  10. 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.

  11. First data on the concentrations and distribution of noble metals in Riphean magmatic complexes of the Bashkir meganticlinorium and eastern margin of the East European Platform

    NASA Astrophysics Data System (ADS)

    Kovalev, S. G.; Puchkov, V. N.; Vysotsky, S. I.; Kovalev, S. S.

    2016-12-01

    The noble metal (PGE and Au) geochemical specialization of igneous rocks of the Bashkir meganticlinorium and adjacent areas of the East European Platform is characterized for the first time. The identical plots of normalized PGE and Au concentrations of igneous rocks in these regions indicate similar conditions and mechanisms of the formation of the noble metal geochemical specialization during the emplacement of magmatic bodies. It is established that a specific feature of noble metal geochemical specialization (the "rhodium anomaly") in magmatic complexes of the Bashkir meganticlinorium and eastern areas of the East European Platform is determined by the concentrations of noble metals in sulfide minerals (pentlandite); i.e., it is "primary" in origin.

  12. Process feasibility, operational parameters and modeling of reverse osmosis membrane systems for the separation and concentration of hazardous, complex industrial wastes

    SciTech Connect

    Slater, C.S.

    1983-01-01

    Reverse osmosis (RO) was applied successfully to the renovation of complex and hazardous industrial wastewaters. Few others have had success in applying RO to the treatment of these high-strength wastewaters, including industrial landfill leachates. Because of the nature of these hazardous waste streams, difficulties are encountered if the RO treatment scheme is not designed or operated for the immediate purpose. The RO system consists of tubular cellulose acetate membranes that can operate in several process modes. The more functional process concentrates the feed, allowing the membrane to separate increments of

  13. 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.

  14. 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

  15. Compound-Specific Stable Carbon Isotope Analysis of Low-Concentration Complex Hydrocarbon Mixtures from Natural Gas Hydrate Systems

    NASA Astrophysics Data System (ADS)

    Plummer, R. E.; Pohlman, J. W.; Coffin, R. B.

    2005-12-01

    A system has been developed to measure the stable carbon isotope (δ13C) composition of dissolved methane, ethane, and propane from natural sediment samples with headspace concentrations as low as 1 ppm using a modified Thermo Electron Trace gas chromatograph (GC) connected to a Finnigan Delta Plus XP isotope ratio mass spectrometer (IRMS). A cryofocusing inlet was connected to the GC which allows 0.02- to 15.0-ml injections into a 10-ml min-1 He carrier stream. Analytes from the variable-volume injection are focused into a small section of fused silica capillary, which is either empty or packed with Poraplot-Q, depending on the analyte(s) of interest. The analytes are then rapidly desorbed (100°C) onto the GC column (1.8 ml min-1), where they undergo separation, combustion and IRMS detection. The sensitivity of the IRMS was improved by the addition of high resistivity amplifiers so that measurements can be obtained with as little as 7-ng of carbon. The analytical precision (2σ) is less than 0.5‰ for methane analysis and less than 1‰ for ethane and propane analyses. The gases are standardized by tank CO2 which has been referenced to the NIST RM 8560 natural gas standard. The samples require no pretreatment, and can be analyzed rapidly (20 samples/day) and with minimal instrument training. Using this system, we have obtained complete stable carbon isotope ethane profiles from sediment cores from microbial and thermogenic gas hydrate regions on the Northern Cascadia Margin. We were able to differentiate the relative thermal and microbial contributions of the gases; and furthermore, we obtained clear evidence for ethanogenesis and ethane oxidation at depths similar to those where methanogenesis and anaerobic methane oxidation (AOM), respectively, occurred. This system will be utilized to analyze headspace and hydrate gas samples from IODP Leg 311. These data will allow us to fully characterize the thermogenic contributions and trace hydrocarbon biogeochemical

  16. 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

  17. Genetic associations for activated partial thromboplastin time and prothrombin time, their gene expression profiles, and risk of coronary artery disease.

    PubMed

    Tang, Weihong; Schwienbacher, Christine; Lopez, Lorna M; Ben-Shlomo, Yoav; Oudot-Mellakh, Tiphaine; Johnson, Andrew D; Samani, Nilesh J; Basu, Saonli; Gögele, Martin; Davies, Gail; Lowe, Gordon D O; Tregouet, David-Alexandre; Tan, Adrian; Pankow, James S; Tenesa, Albert; Levy, Daniel; Volpato, Claudia B; Rumley, Ann; Gow, Alan J; Minelli, Cosetta; Yarnell, John W G; Porteous, David J; Starr, John M; Gallacher, John; Boerwinkle, Eric; Visscher, Peter M; Pramstaller, Peter P; Cushman, Mary; Emilsson, Valur; Plump, Andrew S; Matijevic, Nena; Morange, Pierre-Emmanuel; Deary, Ian J; Hicks, Andrew A; Folsom, Aaron R

    2012-07-13

    Activated partial thromboplastin time (aPTT) and prothrombin time (PT) are clinical tests commonly used to screen for coagulation-factor deficiencies. One genome-wide association study (GWAS) has been reported previously for aPTT, but no GWAS has been reported for PT. We conducted a GWAS and meta-analysis to identify genetic loci for aPTT and PT. The GWAS for aPTT was conducted in 9,240 individuals of European ancestry from the Atherosclerosis Risk in Communities (ARIC) study, and the GWAS for PT was conducted in 2,583 participants from the Genetic Study of Three Population Microisolates in South Tyrol (MICROS) and the Lothian Birth Cohorts (LBC) of 1921 and 1936. Replication was assessed in 1,041 to 3,467 individuals. For aPTT, previously reported associations with KNG1, HRG, F11, F12, and ABO were confirmed. A second independent association in ABO was identified and replicated (rs8176704, p = 4.26 × 10(-24)). Pooling the ARIC and replication data yielded two additional loci in F5 (rs6028, p = 3.22 × 10(-9)) and AGBL1 (rs2469184, p = 3.61 × 10(-8)). For PT, significant associations were identified and confirmed in F7 (rs561241, p = 3.71 × 10(-56)) and PROCR/EDEM2 (rs2295888, p = 5.25 × 10(-13)). Assessment of existing gene expression and coronary artery disease (CAD) databases identified associations of five of the GWAS loci with altered gene expression and two with CAD. In summary, eight genetic loci that account for ∼29% of the variance in aPTT and two loci that account for ∼14% of the variance in PT were detected and supported by functional data.

  18. Homocysteine and prothrombin fragment 1+2 levels in patients with veno-occlusive disease after stem cell transplantation.

    PubMed

    Gerecitano, John; Mathias, Clarissa; Mick, Rosemarie; Duffy, Kathleen M; Luger, Selina; Stadtmauer, Edward A; Schuster, Stephen J; Tsai, Donald; Nasta, Sunita; Berlin, Jesse; Phillips, Deborah K; High, Katherine A; Porter, David L

    2003-04-01

    Veno-occlusive disease (VOD) of the liver remains a major complication after hematopoietic stem cell transplantation (SCT). VOD is thought to develop after hepatic endothelial cells are damaged by high-dose chemotherapy or radiation, causing microthrombosis in hepatic venules. However, the precise mechanisms leading to VOD are not well defined, and a diagnosis is often difficult to establish. It is also difficult to predict which patients are most likely to develop VOD. Elevated levels of homocysteine (HC) have been associated with thrombosis, and prothrombin fragment 1 + 2 (F1 + 2) is a measurable marker for coagulation. Therefore, we performed a prospective cohort study to determine if HC or F1 + 2 levels could be used to predict the development of VOD prior to SCT, or to help establish a diagnosis of VOD in association with other clinical parameters. Plasma levels of these factors were measured before conditioning and serially for 21 days after SCT in 42 consecutive patients undergoing SCT. Eleven of 26 allogeneic SCT recipients developed VOD, whereas no autologous SCT recipient (n = 16) developed VOD (p = 0.008). In patients who developed VOD, HC levels were consistently higher than those seen in non-VOD patients after day 7 of SCT. Patients with VOD also had higher levels of F1 + 2 after SCT, although this marker was less consistently elevated over time. A logistic regression model that evaluated all serial measures of HC and F1 + 2 showed a moderate sensitivity and specificity in diagnosing VOD in allogeneic SCT patients, but neither marker was useful to predict development of VOD when tested prior to SCT.

  19. Genetic Associations for Activated Partial Thromboplastin Time and Prothrombin Time, their Gene Expression Profiles, and Risk of Coronary Artery Disease

    PubMed Central

    Tang, Weihong; Schwienbacher, Christine; Lopez, Lorna M.; Ben-Shlomo, Yoav; Oudot-Mellakh, Tiphaine; Johnson, Andrew D.; Samani, Nilesh J.; Basu, Saonli; Gögele, Martin; Davies, Gail; Lowe, Gordon D.O.; Tregouet, David-Alexandre; Tan, Adrian; Pankow, James S.; Tenesa, Albert; Levy, Daniel; Volpato, Claudia B.; Rumley, Ann; Gow, Alan J.; Minelli, Cosetta; Yarnell, John W.G.; Porteous, David J.; Starr, John M.; Gallacher, John; Boerwinkle, Eric; Visscher, Peter M.; Pramstaller, Peter P.; Cushman, Mary; Emilsson, Valur; Plump, Andrew S.; Matijevic, Nena; Morange, Pierre-Emmanuel; Deary, Ian J.; Hicks, Andrew A.; Folsom, Aaron R.

    2012-01-01

    Activated partial thromboplastin time (aPTT) and prothrombin time (PT) are clinical tests commonly used to screen for coagulation-factor deficiencies. One genome-wide association study (GWAS) has been reported previously for aPTT, but no GWAS has been reported for PT. We conducted a GWAS and meta-analysis to identify genetic loci for aPTT and PT. The GWAS for aPTT was conducted in 9,240 individuals of European ancestry from the Atherosclerosis Risk in Communities (ARIC) study, and the GWAS for PT was conducted in 2,583 participants from the Genetic Study of Three Population Microisolates in South Tyrol (MICROS) and the Lothian Birth Cohorts (LBC) of 1921 and 1936. Replication was assessed in 1,041 to 3,467 individuals. For aPTT, previously reported associations with KNG1, HRG, F11, F12, and ABO were confirmed. A second independent association in ABO was identified and replicated (rs8176704, p = 4.26 × 10−24). Pooling the ARIC and replication data yielded two additional loci in F5 (rs6028, p = 3.22 × 10−9) and AGBL1 (rs2469184, p = 3.61 × 10−8). For PT, significant associations were identified and confirmed in F7 (rs561241, p = 3.71 × 10−56) and PROCR/EDEM2 (rs2295888, p = 5.25 × 10−13). Assessment of existing gene expression and coronary artery disease (CAD) databases identified associations of five of the GWAS loci with altered gene expression and two with CAD. In summary, eight genetic loci that account for ∼29% of the variance in aPTT and two loci that account for ∼14% of the variance in PT were detected and supported by functional data. PMID:22703881

  20. Des-gamma-carboxy Prothrombin and Alpha fetoprotein as Biomarkers for the Early Detection of Hepatocellular Carcinoma

    PubMed Central

    Lok, Anna S.; Sterling, Richard K.; Everhart, James E.; Wright, Elizabeth C.; Hoefs, John C.; Di Bisceglie, Adrian M.; Morgan, Timothy R.; Kim, Hae-Young; Lee, William M.; Bonkovsky, Herbert L.; Dienstag, Jules L.

    2009-01-01

    Background and Aims: The outcome of patients with hepatocellular carcinoma (HCC) remains poor because of late diagnosis. The aim of this study was to compare the accuracy of alpha fetoprotein (AFP) and des-gamma-carboxy prothrombin (DCP) in the early diagnosis of HCC. Methods: Among 1031 patients randomized in the Hepatitis C Antiviral Long-Term Treatment against Cirrhosis (HALT-C) Trial, a nested case-control study of 39 HCC cases (24 early stage) and 77 matched controls was conducted to compare the performance of AFP and DCP. Testing was performed on sera from 12 months prior (month −12) to the time of HCC diagnosis (month 0). Results: The sensitivity and specificity of DCP at month 0 was 74% and 86% at a cutoff of 40 mAU/mL and 43% and 100% at a cutoff of 150 mAU/mL. The sensitivity and specificity of AFP at month 0 was 61% and 81% at a cutoff of 20 ng/mL and 22% and 100% at a cutoff of 200 ng/mL. At month −12, the sensitivity and specificity at the low cutoff was 43% and 94% for DCP and 47% and 75% for AFP. Combining both markers increased the sensitivity to 91% at month 0 and 73% at month 12 but the specificity decreased to 74% and 71%. Diagnosis of early HCC was triggered by surveillance ultrasound in 14, doubling of AFP in 5 and combination of tests in 5 patients. Conclusions: Biomarkers are needed to complement ultrasound in the detection of early HCC but neither DCP nor AFP is optimal. PMID:19852963

  1. 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.

  2. 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

  3. Long-Term Supplementation with Beta Serum Concentrate (BSC), a Complex of Milk Lipids, during Post-Natal Brain Development Improves Memory in Rats.

    PubMed

    Guan, Jian; MacGibbon, Alastair; Fong, Bertram; Zhang, Rong; Liu, Karen; Rowan, Angela; McJarrow, Paul

    2015-06-05

    We have previously reported that the supplementation of ganglioside-enriched complex-milk-lipids improves cognitive function and that a phospholipid-enriched complex-milk-lipid prevents age-related cognitive decline in rats. This current study evaluated the effects of post-natal supplementation of ganglioside- and phospholipid-enriched complex-milk-lipids beta serum concentrate (BSC) on cognitive function in young rats. The diet of male rats was supplemented with either gels formulated BSC (n = 16) or blank gels (n = 16) from post-natal day 10 to day 70. Memory and anxiety-like behaviors were evaluated using the Morris water maze, dark-light boxes, and elevated plus maze tests. Neuroplasticity and white matter were measured using immunohistochemical staining. The overall performance in seven-day acquisition trials was similar between the groups. Compared with the control group, BSC supplementation reduced the latency to the platform during day one of the acquisition tests. Supplementation improved memory by showing reduced latency and improved path efficiency to the platform quadrant, and smaller initial heading error from the platform zone. Supplemented rats showed an increase in striatal dopamine terminals and hippocampal glutamate receptors. Thus BSC supplementation during post-natal brain development improved learning and memory, independent from anxiety. The moderately enhanced neuroplasticity in dopamine and glutamate may be biological changes underlying the improved cognitive function.

  4. 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

  5. Replacement of isoleucine-397 by threonine in the clotting proteinase factor IXa (Los Angeles and Long Beach variants) affects macromolecular catalysis but not L-tosylarginine methyl ester hydrolysis. Lack of correlation between the ox brain prothrombin time and the mutation site in the variant proteins.

    PubMed Central

    Spitzer, S G; Warn-Cramer, B J; Kasper, C K; Bajaj, S P

    1990-01-01

    Previously, from the plasma of unrelated haemophilia-B patients, we isolated two non-functional Factor IX variants, namely Los Angeles (IXLA) and Long Beach (IXLB). Both variants could be cleaved to yield Factor IXa-like molecules, but were defective in catalysing the cleavage of Factor X (macromolecular substrate) and in binding to antithrombin III (macromolecular inhibitor). In the present study we have identified the mutation of IXLA by amplifying the exons (including flanking regions) as well as the 5' end of the gene by polymerase-chain-reaction (PCR) method and sequencing the amplified DNA by the dideoxy chain-termination method. Comparison of the normal IX and IXLA sequences revealed only one base substitution (T----C) in exon VIII of IXLA, with a predicted replacement of Ile-397 to Thr in the mature protein. This mutation is the same as found recently for IXLB. The observation that IXLB and IXLA have the same mutation is an unexpected finding, since, on the basis of their ox brain prothrombin time (PT, a test that measures the ability of the variant Factor IX molecules to inhibit the activation of Factor X by Factor VIIa-tissue factor complex), these variants have been classified into two different groups and were thought to be genetically different. Our observation thus suggests that the ox brain PT does not reflect the locus of mutation in the coding region of the variant molecules. However, our analysis suggests that the ox brain PT is related to Factor IX antigen concentration in the patient's plasma. Importantly, although the mutation in IXLA or IXLB protein is in the catalytic domain, purified IXaLA and IXaLB hydrolyse L-tosylarginine methyl ester at rates very similar to that of normal IXa. These data, in conjunction with our recent data on Factor IXBm Lake Elsinore (Ala-390----Val mutant), strengthen a conclusion that the peptide region containing residues 390-397 of normal Factor IXa plays an essential role in macromolecular substrate catalysis and

  6. Replacement of isoleucine-397 by threonine in the clotting proteinase factor IXa (Los Angeles and Long Beach variants) affects macromolecular catalysis but not L-tosylarginine methyl ester hydrolysis. Lack of correlation between the ox brain prothrombin time and the mutation site in the variant proteins.

    PubMed

    Spitzer, S G; Warn-Cramer, B J; Kasper, C K; Bajaj, S P

    1990-01-01

    Previously, from the plasma of unrelated haemophilia-B patients, we isolated two non-functional Factor IX variants, namely Los Angeles (IXLA) and Long Beach (IXLB). Both variants could be cleaved to yield Factor IXa-like molecules, but were defective in catalysing the cleavage of Factor X (macromolecular substrate) and in binding to antithrombin III (macromolecular inhibitor). In the present study we have identified the mutation of IXLA by amplifying the exons (including flanking regions) as well as the 5' end of the gene by polymerase-chain-reaction (PCR) method and sequencing the amplified DNA by the dideoxy chain-termination method. Comparison of the normal IX and IXLA sequences revealed only one base substitution (T----C) in exon VIII of IXLA, with a predicted replacement of Ile-397 to Thr in the mature protein. This mutation is the same as found recently for IXLB. The observation that IXLB and IXLA have the same mutation is an unexpected finding, since, on the basis of their ox brain prothrombin time (PT, a test that measures the ability of the variant Factor IX molecules to inhibit the activation of Factor X by Factor VIIa-tissue factor complex), these variants have been classified into two different groups and were thought to be genetically different. Our observation thus suggests that the ox brain PT does not reflect the locus of mutation in the coding region of the variant molecules. However, our analysis suggests that the ox brain PT is related to Factor IX antigen concentration in the patient's plasma. Importantly, although the mutation in IXLA or IXLB protein is in the catalytic domain, purified IXaLA and IXaLB hydrolyse L-tosylarginine methyl ester at rates very similar to that of normal IXa. These data, in conjunction with our recent data on Factor IXBm Lake Elsinore (Ala-390----Val mutant), strengthen a conclusion that the peptide region containing residues 390-397 of normal Factor IXa plays an essential role in macromolecular substrate catalysis and

  7. 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

  8. 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.

  9. Prothrombin time and activated partial thromboplastin time using a point-of-care analyser (Abaxis VSpro®) in Bennett's wallabies (Macropus rufogriseus).

    PubMed

    Nevitt, B N; Chinnadurai, S K; Watson, M K; Langan, J N; Adkesson, M J

    2016-10-01

    There are few reports of coagulation times in marsupial species. Blood samples collected from 14 Bennett's wallabies (Macropus rufogriseus) under anaesthesia during routine health assessments were analysed for prothrombin time (PT) and activated partial thromboplastin time (aPTT) using a point-of-care analyser (POC) (Abaxis VSPro®). The wallabies had an aPTT mean of 78.09 s and median of 78.1 s. The PT for all wallabies was greater than 35 s, exceeding the longest time measured on the POC. Although PT was significantly longer, aPTT was similar to the manufacturer's domestic canine reference range.

  10. Does point of care prothrombin time measurement reduce the transfusion of fresh frozen plasma in patients undergoing major surgery? The POC-OP randomized-controlled trial

    PubMed Central

    2009-01-01

    Background Bleeding is a frequent complication during surgery. The intraoperative administration of blood products, including packed red blood cells, platelets and fresh frozen plasma (FFP), is often live saving. Complications of blood transfusions contribute considerably to perioperative costs and blood product resources are limited. Consequently, strategies to optimize the decision to transfuse are needed. Bleeding during surgery is a dynamic process and may result in major blood loss and coagulopathy due to dilution and consumption. The indication for transfusion should be based on reliable coagulation studies. While hemoglobin levels and platelet counts are available within 15 minutes, standard coagulation studies require one hour. Therefore, the decision to administer FFP has to be made in the absence of any data. Point of care testing of prothrombin time ensures that one major parameter of coagulation is available in the operation theatre within minutes. It is fast, easy to perform, inexpensive and may enable physicians to rationally determine the need for FFP. Methods/Design The objective of the POC-OP trial is to determine the effectiveness of point of care prothrombin time testing to reduce the administration of FFP. It is a patient and assessor blind, single center randomized controlled parallel group trial in 220 patients aged between 18 and 90 years undergoing major surgery (any type, except cardiac surgery and liver transplantation) with an estimated blood loss during surgery exceeding 20% of the calculated total blood volume or a requirement of FFP according to the judgment of the physicians in charge. Patients are randomized to usual care plus point of care prothrombin time testing or usual care alone without point of care testing. The primary outcome is the relative risk to receive any FFP perioperatively. The inclusion of 110 patients per group will yield more than 80% power to detect a clinically relevant relative risk of 0.60 to receive FFP of

  11. A national study of plasma use in critical care: clinical indications, dose and effect on prothrombin time

    PubMed Central

    2011-01-01

    Introduction Fresh frozen plasma (FFP) is widely used, but few studies have described patterns of plasma use in critical care. We carried out a multicentre study of coagulopathy in intensive care units (ICUs) and here describe overall FFP utilisation in adult critical care, the indications for transfusions, factors indicating the doses used and the effects of FFP use on coagulation. Methods We conducted a prospective, multicentre, observational study of all patients sequentially admitted to 29 adult UK general ICUs over 8 weeks. Daily data throughout ICU admission were collected concerning coagulation, relevant clinical outcomes (including bleeding), coagulopathy (defined as international normalised ratio (INR) >1.5, or equivalent prothrombin time (PT)), FFP and cryoprecipitate use and indications for transfusion. Results Of 1,923 admissions, 12.7% received FFP in the ICU during 404 FFP treatment episodes (1,212 FFP units). Overall, 0.63 FFP units/ICU admission were transfused (0.11 units/ICU day). Reasons for FFP transfusion were bleeding (48%), preprocedural prophylaxis (15%) and prophylaxis without planned procedure (36%). Overall, the median FFP dose was 10.8 ml kg-1, but doses varied widely (first to third quartile, 7.2 to 14.4 ml kg-1). Thirty-one percent of FFP treatments were to patients without PT prolongation, and 41% were to patients without recorded bleeding and only mildly deranged INR (<2.5). Higher volumes of FFP were administered when the indication was bleeding (median doses: bleeding 11.1 ml kg-1, preprocedural prophylaxis 9.8 ml kg-1, prophylaxis without procedure 8.9 ml kg-1; P = 0.009 across groups) and when the pretransfusion INR was higher (ranging from median dose 8.9 ml kg-1 at INR ≤1.5 to 15.7 ml kg-1 at INR >3; P < 0.001 across ranges). Regression analyses suggested bleeding was the strongest predictor of higher FFP dose. Pretransfusion INR was more frequently normal when the transfusion indication was bleeding. Overall, posttransfusion

  12. Self-management of oral anticoagulants with a whole blood prothrombin-time monitor in elderly patients with atrial fibrillation.

    PubMed

    Eldor, Amiram; Schwartz, Joseph

    2002-01-01

    The efficacy of oral anticoagulants (OAC) in reducing the incidence of stroke in elderly patients with atrial fibrillation (AF) has been well documented. The intensity of OAC therapy and deviations in the prothrombin time (PT) are the strongest risk factor for bleeding complications in elderly patients. The aim of this study was to evaluate a more rigorous regulation of OAC by the use of a portable whole blood PT-monitor (CoaguChek) in elderly patients with AF (age 65-80 years). The study group consisted of 20 patients, of whom 17 were evaluable, which were trained to use to CoaguChek monitor and adjust their anticoagulant dose for 12 months. The control group, 20 patients matched for age, gender and the duration of OAC treatment, were tested in an anticoagulant clinic and their OAC dose was adjusted by a physician. To validate the PT-monitor results, the patients performed a total of 129 simultaneous venous blood PT tests at various time points. The correlation coefficient R(2) was 0.707 indicating the accuracy of the CoaguChek results. The self-managed patients perform more frequent measurements 46 +/- 8.9 vs. 15.7 +/- 3.1 PT tests per patient. They demonstrated a within the therapeutic range INR in 80.5% of the tests (95% confidence interval, 76.5-84.1%) as compared to 72.4% (95% confidence interval, 68.5-76.5%) in the control group (p = 0.057). The median value for all CoaguChek International Normalized Ratio (INR) recordings was within therapeutic range in the self-management group as well as in the control group. There were fewer INR results below or above the therapeutic range in the study group. None of the patients had hemorrhagic or thrombotic events during the study. Overall, the study group expressed high satisfaction from using the home monitor. We conclude that home PT monitoring and self-management of OAC are feasible in a motivated population of elderly patients with atrial fibrillation and are probably cost effective.

  13. 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

  14. Solution conformations of the gamma-carboxyglutamic acid domain of bovine prothrombin fragment 1, residues 1-65.

    PubMed

    Charifson, P S; Darden, T; Tulinsky, A; Hughey, J L; Hiskey, R G; Pedersen, L G

    1991-01-15

    Molecular dynamics simulations have been performed (AMBER version 3.1) on solvated residues 1-65 of bovine prothrombin fragment 1 (BF1) by using the 2.8-A resolution crystallographic coordinates as the starting conformation for understanding calcium ion-induced conformational changes that precede experimentally observable phospholipid binding. Simulations were performed on the non-metal-bound crystal structure, the form resulting from addition of eight calcium ions to the 1-65 region of the crystal structure, the form resulting from removal of calcium ions after 107 ps and continuing the simulation, and an isolated hexapeptide loop (residues 18-23). In all cases, the 100-ps time scale seemed adequate to sample an ensemble of solution conformers within a particular region of conformation space. The non-metal-containing BF1 did not unfold appreciably during a 106-ps simulation starting from the crystallographic geometry. The calcium ion-containing structure (Ca-BF1) underwent an interesting conformational reorganization during its evolution from the crystal structure: during the time course of a 107-ps simulation, Ca-BF1 experienced a trans----cis isomerization of the gamma-carboxyglutamic acid-21 (Gla-21)-Pro-22 peptide bond. Removal of the calcium ions from this structure followed by 114 ps of additional molecular dynamics showed significant unfolding relative to the final 20-ps average structure of the 107-ps simulation; however, the Gla-21-Pro-22 peptide bond remained cis. A 265-ps simulation on the termini-protected hexapeptide loop (Cys-18 to Cys-23) containing two calcium ions also did not undergo a trans----cis isomerization. It is believed that the necessary activation energy for the transitional event observed in the Ca-BF1 simulation was largely supplied by global conformational events with a possible assist from relief of intermolecular crystal packing forces. The presence of a Gla preceding Pro-22, the inclusion of Pro-22 in a highly strained loop

  15. Light and low-CO2-dependent LCIB-LCIC complex localization in the chloroplast supports the carbon-concentrating mechanism in Chlamydomonas reinhardtii.

    PubMed

    Yamano, Takashi; Tsujikawa, Tomoki; Hatano, Kyoko; Ozawa, Shin-Ichiro; Takahashi, Yuichiro; Fukuzawa, Hideya

    2010-09-01

    The carbon-concentrating mechanism (CCM) is essential to support photosynthesis under CO2-limiting conditions in aquatic photosynthetic organisms, including the green alga Chlamydomonas reinhardtii. The CCM is assumed to be comprised of inorganic carbon transport systems that, in conjunction with carbonic anhydrases, maintain high levels of CO2 around ribulose-1, 5-bisphosphate carboxylase/oxygenase in a specific compartment called the pyrenoid. A set of transcripts up-regulated during the induction of the CCM was identified previously and designated as low-CO2 (LC)-inducible genes. Although the functional importance of one of these LC-inducible genes, LciB, has been shown recently, the biochemical properties and detailed subcellular localization of its product LCIB remain to be elucidated. Here, using yeast two-hybrid, immunoprecipitation and mass spectrometry analyses we provide evidence to demonstrate that LCIB interacts with the LCIB homologous protein LCIC in yeast and in vivo. We also show that LCIB and LCIC are co-localized in the vicinity of the pyrenoid under LC conditions in the light, forming a hexamer complex of approximately 350 kDa, as estimated by gel filtration chromatography. LCIB localization around the pyrenoid was dependent on light illumination and LC conditions during active operation of the CCM. In contrast, in the dark or under high-CO2 conditions when the CCM was inactive, LCIB immediately diffused away from the pyrenoid. Based on these observations, we discuss possible functions of the LCIB-LCIC complex in the CCM.

  16. Prothrombin time (PT)

    MedlinePlus

    ... you about taking warfarin (Coumadin) the proper way. Risks This test is often done on people who ... urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows ...

  17. Triggers for β-sheet formation at the hydrophobic-hydrophilic interface: high concentration, in-plane orientational order, and metal ion complexation.

    PubMed

    Hoernke, Maria; Falenski, Jessica A; Schwieger, Christian; Koksch, Beate; Brezesinski, Gerald

    2011-12-06

    Amyloid formation plays a causative role in neurodegenerative diseases such as Alzheimer's disease or Parkinson's disease. Soluble peptides form β-sheets that subsequently rearrange into fibrils and deposit as amyloid plaques. Many parameters trigger and influence the onset of the β-sheet formation. Early stages are recently discussed to be cell-toxic. Aiming at understanding various triggers such as interactions with hydrophobic-hydrophilic interfaces and metal ion complexation and their interplay, we investigated a set of model peptides at the air-water interface. We are using a general approach to a variety of diseases such as Alzheimer's disease, Parkinson's disease, and type II diabetes that are connected to amyloid formation. Surface sensitive techniques combined with film balance measurements have been used to assess the conformation of the peptides and their orientation at the air-water interface (IR reflection-absorption spectroscopy). Additionally, the structures of the peptide layers were characterized by grazing incidence X-ray diffraction and X-ray reflectivity. The peptides adsorb to the air-water interface and immediately adopt an α-helical conformation. This helical intermediate transforms into β-sheets upon further triggering. The factors that result in β-sheet formation are dependent on the peptide sequence. In general, the interface has the strongest effect on peptide conformation compared to high concentrations or metal ions. Metal ions are able to prevent aggregation in bulk but not at the interface. At the interface, metal ion complexation has only minor effects on the peptide secondary structure, influencing the in-plane structure that is formed in two dimensions. At the air-water interface, increased concentrations or a parallel arrangement of the α-helical intermediates are the most effective triggers. This study reveals the role of various triggers for β-sheet formation and their complex interplay. Our main finding is that the

  18. Lopap, a prothrombin activator from Lonomia obliqua belonging to the lipocalin family: recombinant production, biochemical characterization and structure–function insights

    PubMed Central

    Reis, Cleyson Valença; Andrade, Sonia Aparecida; Ramos, Oscar Henrique Pereira; Ramos, Celso Raul Romero; Ho, Paulo Lee; Batista, Isabel de Fátima Correia; Chudzinski-Tavassi, Ana Marisa

    2006-01-01

    Using a cDNA library made from Lonomia obliqua caterpillar bristles, we identified a transcript with a 603 bp open reading frame. The deduced protein corresponds to Lopap, a prothrombin activator previously isolated by our group from the bristles of this species. The mature protein is composed by 185 amino acids and shares similarity with members of the lipocalin family. The cDNA encoding the mature form was amplified by PCR, subcloned into pAE vector and used to transform Escherichia coli BL21(DE3) cells. As for the native Lopap, the recombinant fusion protein shows enzymatic activity, promotes prothrombin hydrolysis, generates fragments similar to prethrombin-2 and fragment 1.2 as intermediates, and generates thrombin as the final product. In addition, structural bioinformatics studies indicated several interesting molecular features, including the residues that could be responsible for Lopap's serine protease-like activity and the role of calcium binding in this context. Such catalytic activity has never been found in other members of the lipocalin family. This is the first report describing the recombinant production and biochemical characterization of a Lonomia obliqua lipocalin, as well as the structural features that could be responsible for its serine protease-like catalytic activity. PMID:16734589

  19. 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.

    PubMed

    Ma, Jing; Kannan, Kurunthachalam; Cheng, Jinping; Horii, Yuichi; Wu, Qian; Wang, Wenhua

    2008-11-15

    Environmental pollution arising from electronic waste (e-waste) disposal and recycling has received considerable attention in recent years. Treatment, at low temperatures, of e-wastes that contain polyvinylchloride and related polymers can release polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). Although several studies have reported trace metals and polybrominated diphenyl ethers (PBDEs) released from e-waste recycling operations, environmental contamination and human exposure to PCDD/Fs from e-waste recycling operations are less well understood. In this study, 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 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 11400 pg/g for shredder waste, 3460 to 9820 pg/g dry weight for leaves, 2560 to 148000 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 (44.5-531 pg/g dry wt) 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 (3.44-33.8 pg/g dry wt) 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

  20. Effect of injectable trace mineral complex supplementation on development of ovarian structures and serum copper and zinc concentrations in over-conditioned Holstein cows.

    PubMed

    González-Maldonado, Juan; Rangel-Santos, Raymundo; Rodríguez-de Lara, Raymundo; García-Peña, Oswaldo

    2017-03-28

    This study evaluated the effect of injecting trace minerals on reproductive performance in over-conditioned Holstein cows before synchronized estrus. Multiparous non-lactating, over-conditioned repeat breeder cows (n=20) were assigned randomly to one of two treatments: 1) control (n=10), and 2) supplementation with an injectable trace mineral complex 25days before expected synchronized estrus (n=10). Follicular waves were synchronized by intravaginal insertion of a CIDR for eight days and an intramuscular (i.m.) injection of a GnRH analogue. Estrus was induced at CIDR removal by an i.m. injection of PGF2α. Blood samples were collected before and after synchronized estrus. The response variables were follicle population (FP), diameter of the preovulatory follicle at CIDR removal (DFP0) and at estrus detection (DFP1), time of estrus after CIDR removal (TE), area of corpus luteum (ACL), pregnancy rate and copper and zinc serum concentrations. The statistical analysis of the variables was carried out with SAS. The FP, DFP0, DFP1, TE, ACL and serum concentrations of copper and zinc were not affected by the trace mineral injection (P>0.05). Even though pregnancy rate at 40 (77.78±13.46 vs 44.44±16.56%) and 60days after AI (66.67±15.71 vs 33.33±15.71%) was numerically higher for cows injected with trace minerals than for the control group, the differences were not significant (P>0.05). In conclusion, while follicular and corpus luteum development were not affected by trace mineral injection, it may be a feasible way to increase the pregnancy rate in over-conditioned cows.

  1. Assessment of the 20210 G to A prothrombin variant in a sample of patients from the French Basque Country with various thrombophilic conditions.

    PubMed

    Bauduer, F; Ducout, L; Freyburger, G

    2003-06-01

    We investigated the distribution of the prothrombin variant G20210A (PT20210A) in a sample of 103 patients (mean age: 34.5 years) living in the French Basque Country and presenting with conditions known to be significantly associated with this peculiar mutation according to a literature review. These patients suffered from repeated personal or familial venous thromboses, stroke at young age, or repetitive maternal-fetal disorders (abortions, preeclampsia, fetal growth retardation). Five patients (4.8%) were found to be carriers: two homozygotes and three heterozygotes (one also heterozygote for factor V Leiden). Of note, two presented with mesenteric venous thrombosis. The distribution of PT20210A among our sample was comparable to data from Western European series albeit a tendency for lower mutation prevalence was observed in our subgroup with obstetrical disorders. In addition, no significant difference in PT20210A frequency was evidenced between autochthonous Basques and individuals from other origins.

  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. Coagulation factors bound to procoagulant platelets concentrate in cap structures to promote clotting.

    PubMed

    Podoplelova, Nadezhda A; Sveshnikova, Anastasia N; Kotova, Yana N; Eckly, Anita; Receveur, Nicolas; Nechipurenko, Dmitry Yu; Obydennyi, Sergey I; Kireev, Igor I; Gachet, Christian; Ataullakhanov, Fazly I; Mangin, Pierre H; Panteleev, Mikhail A

    2016-09-29

    Binding of coagulation factors to phosphatidylserine (PS)-exposing procoagulant-activated platelets followed by formation of the membrane-dependent enzyme complexes is critical for blood coagulation. Procoagulant platelets formed upon strong platelet stimulation, usually with thrombin plus collagen, are large "balloons" with a small (∼1 μm radius) "cap"-like convex region that is enriched with adhesive proteins. Spatial distribution of blood coagulation factors on the surface of procoagulant platelets was investigated using confocal microscopy. All of them, including factors IXa (FIXa), FXa/FX, FVa, FVIII, prothrombin, and PS-sensitive marker Annexin V were distributed nonhomogeneously: they were primarily localized in the "cap," where their mean concentration was by at least an order of magnitude, higher than on the "balloon." Assembly of intrinsic tenase on liposomes with various PS densities while keeping the PS content constant demonstrated that such enrichment can accelerate this reaction by 2 orders of magnitude. The mechanisms of such acceleration were investigated using a 3-dimensional computer simulation model of intrinsic tenase based on these data. Transmission electron microscopy and focal ion beam-scanning electron microscopy with Annexin V immunogold-labeling revealed a complex organization of the "caps." In platelet thrombi formed in whole blood on collagen under arterial shear conditions, ubiquitous "caps" with increased Annexin V, FX, and FXa binding were observed, indicating relevance of this mechanism for surface-attached platelets under physiological flow. These results reveal an essential heterogeneity in the surface distribution of major coagulation factors on the surface of procoagulant platelets and suggest its importance in promoting membrane-dependent coagulation reactions.

  4. Tranexamic Acid

    MedlinePlus

    ... to improve blood clotting including Factor IX complex concentrate (AlphaNine SD, Bebulin VH, Benefix, Mononine, Profilmine SD) and activated prothrombin complex concentrate (Feiba NF); and tretinoin. Tell your doctor you ...

  5. Prevalence of factor V Leiden and prothrombin G20210A mutation in a large French population selected for nonthrombotic history: geographical and age distribution.

    PubMed

    Mazoyer, Elisabeth; Ripoll, Laurent; Gueguen, René; Tiret, Laurence; Collet, Jean-Philippe; dit Sollier, Claire Bal; Roussi, Jacqueline; Drouet, Ludovic

    2009-10-01

    Among inherited risk factors for venous thrombosis, the most common are the FV-G1691A and FII-G20210A polymorphisms. The FV-G1691A polymorphism is preferentially observed in Europe, with differences between European countries. The FII-G20210A polymorphism is observed all over the world. The study was designed to compare the prevalence of the FV-G1691A and FII-G20210A polymorphisms in a large French population of unrelated individuals with no thrombotic disease history and to determine the age and geographical distributions. Over a period of 18 months, 6154 individuals were included throughout France and FV-G1691A and FII-G20210A polymorphisms were determined. The FV-G1691A prevalence was 3.84% (95% confidence interval 3.35-4.33) and the FII-G20210A prevalence was 3.07% (95% CI 2.63-3.51). A north-east/south-west gradient was observed in the FV-G1691A geographical distribution. No difference was observed in the geographical distribution of FII-G20210A polymorphism nor in the age distribution of the two polymorphisms. The prevalence of the two polymorphisms was similar whatever the blood group (O or non-O). Plasma D-dimers were significantly higher in healthy individuals with FV-G1691A but not in individuals with FII-G20210A. Thirty percent of variation in plasma prothrombin level was explained by environmental factors (serum cholesterol, age, oral contraception, hormonal replacement therapy, body mass index, sex) and genetic factors (FII-G20210A). As expected, individuals with FII-G20210A displayed higher plasma prothrombin level compared with individuals with wild type. However, this was not associated with a modification of the fibrin clot elastic modulus. This study shows a differential distribution of the two polymorphisms among the French territory. These polymorphisms confer a very mild hypercoagulable state as shown by the limited increased in basal D-dimers in mutated FV-G1691A populations and only a trend that does not reach statistical significance for FII

  6. 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.

  7. Substitution of egg yolk by a cyclodextrin-cholesterol complex allows a reduction of the glycerol concentration into the freezing medium of equine sperm.

    PubMed

    Blommaert, Didier; Franck, Thierry; Donnay, Isabelle; Lejeune, Jean-Philippe; Detilleux, Johann; Serteyn, Didier

    2016-02-01

    The aim of this work was to completely replace the egg yolk a classical diluent for freezing equine semen by a cyclodextrin-cholesterol complex. At the same time, the reduction in the glycerol content used for cryopreservation and the incubation time between sperm and the freezing media were evaluated. Horse ejaculates were frozen with four different freezing extenders: a frozen reference medium (IF) containing egg yolk and 2.5% glycerol and media without egg yolk but supplemented with 1.5 mg 2-hydroxypropyl-beta-cyclodextrin cholesterol (HPβCD-C) complex and containing either 1% (G1), 2% (G2) or 3% glycerol (G3). Three incubation times (90, 120 and 180 min) at 4 °C between the fresh semen and the different media were tested before freezing. Viability and motility analyses were performed with computer assisted semen analysis (CASA). Results showed that the freezing media containing the HPβCD-C complex with 1%, 2% and 3% glycerol significantly improve the 3 in vitro parameters of post thawing semen quality (viability, progressive and total mobilities) compared to IF. The best improvement of the parameters was obtained with G1 medium and the longest contact time. The substitution of egg yolk by HPβCD-C complex allows the decrease of protein charge of the medium while favouring the cholesterol supply to membrane spermatozoa offering it a better resistance to osmotic imbalance and a better tolerance to the glycerol toxicity. Our results highlight that the egg yolk of an extender for the freezing of horse semen can be completely substituted by HPβCD-C complex.

  8. Synergism between urinary prothrombin fragment 1 and urine: a comparison of inhibitory activities in stone-prone and stone-free population groups.

    PubMed

    Webber, Dawn; Rodgers, Allen L; Sturrock, Edward D

    2002-09-01

    South African blacks rarely form kidney stones compared with whites. This study investigated whether purified urinary prothrombin fragment 1 (UPTF1) derived from blacks is a more potent inhibitor of calcium oxalate crystallisation than that from whites. UPTF1 was purified from the urine of both population groups and their inhibitory activities were compared in a cross-over design in which each protein was tested in ultrafiltered urine from both population groups. Coulter Multisizer, [14C]-oxalate deposition and scanning electron microscopy experiments were used to monitor crystallisation. The study has demonstrated for the first time that UPTF1 promotes nucleation and that inhibitory activity is synergistically dependent upon urine composition. The activity of the whites' UPTF1 was greater than that of the blacks in the whites' urine (e.g. particle size decrease: 31.7% vs. 25.2%), while the blacks' UPTF1 was superior to that of the whites in the blacks' urine (e.g. particle size decrease: 46.5% vs. 32.4%). In addition, when tested in their respective endogenous urines, the blacks' UPTF1 demonstrated superior inhibitory activity on an absolute scale (e.g. particle size decrease: 46.5% vs. 31.7%). Thus, the urine composition of black South Africans may influence their UPTF1 conformation, conferring greater efficacy for inhibition of calcium oxalate crystallisation.

  9. 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.

  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. 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

  12. Alterations of serum zinc, copper, manganese, iron, calcium, and magnesium concentrations and the complexity of interelement relations in patients with obsessive-compulsive disorder.

    PubMed

    Shohag, Hasanuzzaman; Ullah, Ashik; Qusar, Shalahuddin; Rahman, Mustafizur; Hasnat, Abul

    2012-09-01

    The purpose of the present study was to evaluate the status of serum trace elements: zinc, copper, manganese, iron, calcium, and magnesium concentrations in obsessive-compulsive disorder patients. Forty-eight obsessive-compulsive disorder patients and 48 healthy volunteers were included in this study. Patients were recruited from Bangabandhu Sheikh Mujib Medical University by random sampling. Serum trace element concentrations were determined using flame atomic absorption spectroscopy (for zinc, copper, iron, calcium, and magnesium) as well as graphite furnace atomic absorption spectroscopy (for manganese). Data were analyzed using independent t test, Pearson's correlation analysis, regression analysis, and ANOVA. Statistical analysis of these data showed a definite pattern of variation among certain elements in patients with obsessive-compulsive disorder compared to controls. In patients' serum, zinc, iron, and magnesium concentrations decreased significantly (p<0.05) compared to the controls. Serum manganese and calcium concentrations were significantly higher (p<0.05) in patients compared to the controls. These data showed a definite imbalance in the interelement relations in obsessive-compulsive disorder patients compared to controls and therefore suggest a disturbance in the element homeostasis.

  13. 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...

  14. 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...

  15. Photovoltaic concentrators

    NASA Astrophysics Data System (ADS)

    Boes, E. C.

    1980-01-01

    A status report on photovoltaic (PV) concentrators technology is presented. The major topics covered are as follows: (1) current PV concentrator arrays; designs, performances, and costs; (2) current PV concentrator array components; cells and cell assemblies, optical concentrators, support structures, tracking, and drive; (3) design of PV concentrator arrays; and (4) array manufacturing technology.

  16. 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.

  17. 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

    2014-09-26

    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.

  18. Influence of 8 and 24-h storage of whole blood at ambient temperature on prothrombin time, activated partial thromboplastin time, fibrinogen, thrombin time, antithrombin and D-dimer.

    PubMed

    Kemkes-Matthes, Bettina; Fischer, Ronald; Peetz, Dirk

    2011-04-01

    This study evaluates the effect of whole blood storage on common coagulation parameters in order to confirm or revise acceptable storage limits as defined by current guidelines and diverse study reports. Aliquots were taken from the citrated whole blood of inpatients and outpatients (n = 147) within 4 h after blood withdrawal and after extended storage of whole blood for 8 and 24 h at ambient temperature. Aliquots were centrifuged and analyzed for prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen (Fbg), antithrombin (AT), thrombin time (TT) and D-dimer. For each parameter, samples from 33-56 patients were investigated covering a wide range of normal and pathological values. Samples from patients receiving heparin were excluded from analyses of APTT and TT. All assays were performed using reagents and an analyzer from Siemens Healthcare Diagnostics Products GmbH. The mean percentage change after 8 and 24-h storage was below 10% for all parameters. Considering the changes in individual samples, all parameters can be reliably tested after 8-h storage, since less than 15% of the samples demonstrated individual changes of above 10%. The acceptable storage time can be extended to 24 h for PT, TT and D-dimer. Clinically relevant changes were detected after 24-h storage for APTT: 41% of the investigated samples demonstrated changes of above 10%. After 24-h storage, changes for Fbg and AT values were more than 15% in five out of 49 and in three out of 45 samples, respectively. This sporadic increase of values is clinically acceptable except for borderline samples.

  19. The prevalence of methylenetetrahydrofolate reductase 677 C-T, factor V 1691 G-A, and prothrombin 20210 G-A mutations in healthy populations in Setif, Algeria.

    PubMed

    Bourouba, Romyla; Houcher, Bakhouche; Djabi, Farida; Egin, Yonca; Akar, Nejat

    2009-10-01

    The polymorphic mutation 677 C-T in the methylenetetrahydrofolate reductase (MTHFR) gene presents a heterogeneous worldwide distribution and is associated with different disorders such as cardiovascular disease. Its frequency shows great ethnic and geographic variations. The aim of this work is to determine the frequency of MTHFR 677 C-T and coexistence of MTHFR 677 C-T with 2 other common, hereditary thrombophilia causes-namely, factor V 1691 G-A and prothrombin (PT) 20210 G-A mutation-in the Sétif region of Algeria. The study involved 147 apparently healthy participants (82 men and 65 women). Genotyping was carried out by a real-time polymerase chain reaction. The MTHFR 677T carrier frequency was found to be 54.4% (80/147); 59 individuals were heterozygous (40.1%), and 21 were homozygous (14.3%). The frequency of MTHFR 677T was found to be 34.3%. Among the 147 individuals, 3 (2.0%) had factor V Leiden, and 5 (3.4%) had PT 20210 A mutation. Of the 80 participants with MTHFR 677T mutation, 2 had heterozygote factor V 1691 G-A gene mutation, and 4 had heterozygote PT 20210 G-A gene mutation. The results showed that MTHFR 677T prevalence is quite high: an allelic frequency of 34.3% with a genotype frequency of 14.3%. Factor V 1691 G-A and PT 20210 G-A gene mutations are rare in the healthy population of the Sétif region of Algeria.

  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.

  1. Persistence of high lead concentrations and associated effects in Tundra Swans captured near a mining and smelting complex in northern Idaho

    USGS Publications Warehouse

    Blus, L.J.; Henny, C.J.; Hoffman, D.J.; Sileo, L.; Audet, D.J.

    1999-01-01

    Lead poisoning of waterfowl, particularly tundra swans (Cygnus columbianus), has been documented in the Coeur d'Alene River Basin in northern Idaho for nearly a century. Over 90% of the lead-poisoned tundra swans in this area that were necropsied have no ingested lead shot. Spent lead shot from hunting activities over the years is therefore a minor source of lead in these swans. The migrating swans accumulated lethal burdens of lead from ingestion of sediments and aquatic vegetation during a short stopover in the spring. The lead originated from mining and smelting activities. Lead concentrations and physiological characteristics of blood were compared in swans captured in swim-in traps, with moribund swans caught by hand in the lead-contaminated area in 1987 and 1994-1995 and with birds captured by night-lighting in reference areas in 1994-1995. Blood lead concentrations in swans were highest in moribund birds (3.3 ?g g-1 in 1987 and 1995), intermediate in those trapped in the contaminated area (0.82 ?g g-1 in 1987 and 1.8 ?g g-1 in 1995), and lowest (0.11 ?g g-1) in those trapped in the reference areas. daminolevulinic acid dehydratase (ALAD) was significantly inhibited in swans from the contaminated area. Hematocrit and hemoglobin were significantly depressed only in moribund swans. Of the 19 swans found moribund and euthanized, 18 were classified as having lead toxicosis on the basis of lead levels in blood (1.3 to 9.6 ?g g-1) and livers (6 to 40 ?g g-1) and necropsy findings. The 19th swan had aspergillosis. There was no evidence that effects of lead on tundra swans had diminished from 1987 to 1995.

  2. 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.

  3. Exploration of the Potential Energy Surfaces, Prediction of Atmospheric Concentrations, and Prediction of Vibrational Spectra for the HO2···(H2O)n (n=1-2) Hydrogen Bonded Complexes

    PubMed Central

    Alongi, Kristin S.; Dibble, Theodore S.; Shields, George C.; Kirschner, Karl N.

    2008-01-01

    The hydroperoxy radical (HO2) plays a critical role in Earth’s atmospheric chemistry as a component of many important reactions. The self-reaction of hydroperoxy radicals in the gas phase is strongly affected by the presence of water vapor. In this work we explore the potential energy surfaces of hydroperoxy radicals hydrogen bonded to one or two water molecules, and predict atmospheric concentrations and vibrational spectra of these complexes. We predict that when the HO2 concentration is on the order of 108 molecules·cm-3 at 298K, that the number of HO2···H2O complexes is on the order of 107 molecules·cm-3 and the number of HO2···(H2O)2 complexes is on the order of 106 molecules·cm-3. Using the computed abundance of HO2···H2O, we predict that, at 298K, the bimolecular rate constant for HO2···H2O + HO2 is about ten times that for HO2 + HO2. PMID:16526652

  4. Existence of a squamous cell carcinoma antigen-immunoglobulin complex causes a deviation between squamous cell carcinoma antigen concentrations determined using two different immunoassays: first report of squamous cell carcinoma antigen coupling with immunoglobulin A.

    PubMed

    Mori, Eriko; Kurano, Makoto; Tobita, Akiko; Shimosaka, Hironori; Yatomi, Yutaka

    2017-01-01

    Background Squamous cell carcinoma antigen is used as a tumour marker and is routinely measured in clinical laboratories. We validated two different immunoassays and found three cases in which the squamous cell carcinoma antigen concentrations deviated greatly between the two immunoassays. Here, we aimed to elucidate the mechanisms responsible for these deviations. Methods The squamous cell carcinoma antigen concentrations were determined using the ARCHITECT SCC (CLIA method) and the ST AIA-PACK SCC (FEIA method). We performed polyethylene glycol precipitation and size exclusion chromatography to assess the molecular weight and spike recovery and absorption tests to examine the presence of an autoantibody. Results Both methods exhibited good performances for the measurement of squamous cell carcinoma antigen, although a correlation test showed large differences in the squamous cell carcinoma antigen concentrations measured using the two methods in three cases. The results of polyethylene glycol treatment and size exclusion chromatography indicated the existence of a large molecular weight squamous cell carcinoma antigen in these three cases. The spike recovery tests suggested the possible presence of an autoantibody against squamous cell carcinoma antigen. Moreover, the absorption test revealed that large squamous cell carcinoma antigen complexes were formed by the association of squamous cell carcinoma antigen with IgG in two cases and with both IgG and IgA in one case. Conclusions This study describes the existence of large molecular weight squamous cell carcinoma antigen that has complexed with immunoglobulin in the serum samples. The reason for the deviations between the two immunoassays might be due to differences of their reactivities against the squamous cell carcinoma antigen immune complexes with their autoantibody. To our knowledge, this is the first report to describe the coupling of squamous cell carcinoma antigen with IgA.

  5. Surface complexation modeling for predicting solid phase arsenic concentrations in the sediments of the Mississippi River Valley alluvial aquifer, Arkansas, USA

    USGS Publications Warehouse

    Sharif, M.S.U.; Davis, R.K.; Steele, K.F.; Kim, B.; Hays, P.D.; Kresse, T.M.; Fazio, J.A.

    2011-01-01

    The potential health impact of As in drinking water supply systems in the Mississippi River Valley alluvial aquifer in the state of Arkansas, USA is significant. In this context it is important to understand the occurrence, distribution and mobilization of As in the Mississippi River Valley alluvial aquifer. Application of surface complexation models (SCMs) to predict the sorption behavior of As and hydrous Fe oxides (HFO) in the laboratory has increased in the last decade. However, the application of SCMs to predict the sorption of As in natural sediments has not often been reported, and such applications are greatly constrained by the lack of site-specific model parameters. Attempts have been made to use SCMs considering a component additivity (CA) approach which accounts for relative abundances of pure phases in natural sediments, followed by the addition of SCM parameters individually for each phase. Although few reliable and internally consistent sorption databases related to HFO exist, the use of SCMs using laboratory-derived sorption databases to predict the mobility of As in natural sediments has increased. This study is an attempt to evaluate the ability of the SCMs using the geochemical code PHREEQC to predict solid phase As in the sediments of the Mississippi River Valley alluvial aquifer in Arkansas. The SCM option of the double-layer model (DLM) was simulated using ferrihydrite and goethite as sorbents quantified from chemical extractions, calculated surface-site densities, published surface properties, and published laboratory-derived sorption constants for the sorbents. The model results are satisfactory for shallow wells (10.6. m below ground surface), where the redox condition is relatively oxic or mildly suboxic. However, for the deep alluvial aquifer (21-36.6. m below ground surface) where the redox condition is suboxic to anoxic, the model results are unsatisfactory. ?? 2011 Elsevier Ltd.

  6. Synchronous Volatilization of Sn, Zn, and As, and Preparation of Direct Reduction Iron (DRI) from a Complex Iron Concentrate via CO Reduction

    NASA Astrophysics Data System (ADS)

    Li, Guanghui; You, Zhixiong; Zhang, Yuanbo; Rao, Mingjun; Wen, Peidan; Guo, Yufeng; Jiang, Tao

    2014-09-01

    Sn-, Zn-, and As-bearing iron ores are typical complex ores and are abundantly reserved in China. This kind of ore is difficult to use effectively due to the complicated relationships between iron and the other valuable metal minerals. Excessive Sn, Zn, and As contents would adversely affect ferrous metallurgy operation as well as the quality of the products. In this study, thermodynamic calculations revealed that it was feasible to synchronously volatilize Sn, Zn, and As via CO reduction. Experimental results showed that preoxidation was necessary for the subsequent reductive volatilization of Zn from the pellets, and the proper preoxidation temperature was 700-725°C under air atmosphere. Synchronous volatilization of Sn, Zn, and As was realized by roasting under weak reductive atmosphere after the pellets were preoxidized. The volatilization ratios of 75.88% Sn, 78.88% Zn, and 84.43% As were obtained, respectively, under the conditions by reduction at 1000°C for 100 min with mixed gas of 50% CO + 50% CO2 (in vol.). A metallic pellet (direct reduction iron) with total iron grade of 87.36%, Fe metallization ratio of 89.27%, and residual Sn, Zn, and As contents of 0.071%, 0.009%, and 0.047%, respectively, was prepared. Sn and As were mainly volatilized during weak reductive atmosphere roasting, and those volatilized in the metallization reduction process were negligible. Most of Zn (78.88%) was volatilized during weak reductive atmosphere roasting, while the metallization reduction process only contributed to 16.10% of total Zn volatilization.

  7. Complex correlation between excitatory amino acid-induced increase in the intracellular Ca2+ concentration and subsequent loss of neuronal function in individual neocortical neurons in culture.

    PubMed Central

    Witt, M R; Dekermendjian, K; Frandsen, A; Schousboe, A; Nielsen, M

    1994-01-01

    Primary cultures of cerebral cortical neurons and single-cell imaging of intracellular free Ca2+ concentration ([Ca2+]i) with the ratiometric dye fura-2 were used to assess excitatory amino acid (EAA)-induced neurotoxicity; the loss of neuronal function as defined by the ability of the cells to respond to K(+)-induced depolarization by a transient increase in Ca2+ influx was measured. The responsiveness of individual neurons was measured quantitatively as the [Ca2+]i values of the second KCl (2.KCl) stimulation divided by those of the first KCl (1.KCl) stimulation, giving the value of the ratio (2.KCl/1.KCl). Exposure to EAAs led to an increase in [Ca2+]i, but no simple correlation between the increase in [Ca2+]i and neuronal responsiveness could be demonstrated. Rather, below a threshold level of [Ca2+]i (ca. 1 microM), the neuronal responsiveness was largely independent of the glutamate receptor-agonist-induced increase in [Ca2+]i. However, when [Ca2+]i increased above this threshold level, the neurons almost invariably lost the ability to respond to a K(+)-induced depolarization, particularly after exposure to glutamate. Therefore, the cortical neurons were found to be exceptionally vulnerable to the glutamate-induced loss of function when compared with the effect induced by the glutamate receptor subtype-specific agonists, N-methyl-D-aspartate, quisqualate, and 2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl) propionate. The findings suggest that the loss of neuronal membrane polarization precedes plasma membrane disruption and is a sensitive marker of EAA-induced neurodegeneration observed at the single-cell level. Images PMID:7527559

  8. 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

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

    SciTech Connect

    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 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 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.

  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. 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

    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.

  12. Concentrating collectors

    SciTech Connect

    Not Available

    1981-06-01

    Selected specifications from sixteen concentrating collector manufacturers are tabulated. Eleven are linear parabolic trough collectors, and the others include slats, cylindrical trough, linear Fresnel lens, parabolic cylindrical Fresnel lens, and two point focus parabolic dish collectors. Also included is a brief discussion of the operating temperatures and other design considerations for concentrating collectors. (LEW)

  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. Time resolved study of three ruthenium(II) complexes at micellar surfaces: A new long excited state lifetime probe for determining critical micelle concentration of surfactant nano-aggregates.

    PubMed

    Patra, Digambara; Chaaban, Ahmad H; Darwish, Shaza; Saad, Huda A; Nehme, Ali S; Ghaddar, Tarek H

    2016-02-01

    Three different ruthenium complexes have been synthesized and their luminescence properties in different solvent environments are reported. Luminescence intensities and excited state lifetimes of Ru-I, Ru-II and Ru-III vary with solvent viscosity. The excited state lifetime of Ru-I linearly increases in the viscosity range 1.76-12,100cP. Ru-II shows two linear increases: one in the low and another in the high viscosity ranges, whereas Ru-III illustrates a linear enhancement only in the low viscosity range. Interestingly, luminescence intensities and excited state lifetimes of Ru-I, Ru-II and Ru-III are found to be sensitive to nano-aggregation. However, the surfactant head charge and that of the ruthenium center as well as the hydrophobic tail of the ancillary ligand of the complexes have a great role in deciding the nature of the interaction and on the excited state properties at micellar surfaces. It is proposed that the long lifetime of Ru-III in water could be due to the coiling of the carbon chain of the ancillary ligand around the ruthenium center. At micelle surface, this coiling of the carbon chain is lost due to the parallel alignment with surfactants and thus quenching of the excited state lifetime is seen. Furthermore, it is shown that the variation of the excited state lifetime with respect to the change in surfactant concentration is a result of the formation of micelles from the surfactant monomer, thus, a novel technique for the determination of the critical micelle concentration (cmc) based on the long excited state lifetime of Ru-III located at the micellar nano-aggregates is reported.

  15. 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.

  16. Pre-operative coagulopathy management of a neonate with complex congenital heart disease: a case study.

    PubMed

    Stammers, A H; Rauch, E D; Willett, L D; Newberry, J W; Duncan, K F

    2000-03-01

    Severe coagulation defects often develop in neonates undergoing cardiac surgery, both as a result of the surgical intervention, and as pre-existing defects in the hemostatic mechanisms. The following case report describes a newborn patient with complex congenital heart disease and respiratory failure whose pre-operative coagulopathy was aggressively managed prior to surgical correction. A 5-day-old, 2.5 kg child presented with interrupted aortic arch, ventricular septal defect, atrial septal defect, and patent ductus arteriosus. On admission, he was in respiratory arrest suffering from profound acidemia. In addition, the child was hypothermic (30.1 degrees C), septic (Streptococcus viridans), and coagulopathic (disseminated intravascular coagulation-DIC). The patient was immediately intubated and initial coagulation assessment revealed the following: prothrombin time (PT) 48.9 s (international normalized ratio (INR) 15.7), activated partial thromboplastin time (aPTT) >106 s, platelet count 30,000 mm(3), fibrinogen 15 mg dL(-1) and antithrombin III (AT-III) 10%. Before cardiac surgery could be performed, the patient's DIC was corrected with the administration of cryoprecipitate (15 ml), fresh frozen plasma (300 ml), and platelets (195 ml). In spite of the large transfusion of fresh frozen plasma, the AT-III activity, measured as a percentage, remained depressed at 33. Initial thromboelastographic (TEG) determination revealed an index of +2.02, and following 100 IU administration of an AT-III concentrate, declined to -2.32. Sequential TEG profiles were performed over several days, with the results used to guide both transfusion and medical therapy. The congenital heart defect correction was subsequently performed with satisfactory initial results, but the patient developed a fungal infection and expired on the 16th post-operative day. The present case describes techniques of coagulation management for a newborn with both a severe hemostatic defect and congenital

  17. Improving ozone modeling in complex terrain at a fine grid resolution - Part II: Influence of schemes in MM5 on daily maximum 8-h ozone concentrations and RRFs (Relative Reduction Factors) for SIPs in the non-attainment areas

    NASA Astrophysics Data System (ADS)

    Kim, Yunhee; Fu, Joshua S.; Miller, Terry L.

    2010-06-01

    Part II presents a comprehensive evaluation of CMAQ for August of 2002 on twenty-one sensitivity simulations (detailed in Part I) in MM5 to investigate the model performance for O 3 SIPs (State Implementation Plans) in the complex terrain. CMAQ performance was quite consistent with the results of MM5, meaning that accurate meteorological fields predicted in MM5 as an input resulted in good model performance of CMAQ. In this study, PBL scheme plays a more important role than its land surface models (LSMs) for the model performance of CMAQ. Our results have shown that the outputs of CMAQ on eighteen sensitivity simulations using two different nudging coefficients for winds (2.5 and 4.5 × 10 -4 s -1, respectively) tend to under predict daily maximum 8-h ozone concentrations at valley areas except the TKE PBL sensitivity simulations (ETA M-Y PBL scheme with Noah LSMs and 5-layer soil model and Gayno-Seaman PBL) using 6.0 × 10 -4 s -1 with positive MB (Mean Bias). At mountain areas, none of the sensitivity simulations has presented over predictions for 8-h O 3, due to relatively poor meteorological model performance. When comparing 12-km and 4-km grid resolutions for the PX simulation in CMAQ statistics analysis, the CMAQ results at 12-km grid resolution consistently show under predictions of 8-h O 3 at both of valley and mountain areas and particularly, it shows relatively poor model performance with a 15.1% of NMB (Normalized Mean Bias). Based on our sensitivity simulations, the TKE PBL sensitivity simulations using a maximum value (6 × 10 -4) among other sensitivity simulations yielded better model performance of CMAQ at all areas in the complex terrain. As a result, the sensitivity of RRFs to the PBL scheme may be considerably significant with about 1-3 ppb in difference in determining whether the attainment test is passed or failed. Furthermore, we found that the result of CMAQ model performance depending on meteorological variations is affected on estimating

  18. [Detection of autowave distribution of the concentration of a dinitrosyl iron complex with glutathione, formed in an aqueous solution of S-nitrosoglutathione after the addition to it of a mixture of glutathione and ferrous iron].

    PubMed

    Vanin, A F; Mikoian, V D; Kubrina, L N

    2010-01-01

    The formation of dark green concentric autowaves of the distribution of the concentration of dinitrosyl iron complex (DNIC) with glutathione in a thin (0.3 mm thick) layer of 0.5 M solution of S-nitrosoglutathione in 15 mM HEPES buffer (pH 7.7) after applying on its surface of a drop of a solution of glutathione (0.5 mM) and ferrous iron (1 mM) in the same buffer of volume 10 microl was detected. At regular intervals, the picture of autowaves changed for 0.4-0.6 s over a period of 3 s after the application of the drop onto the solution. Then the structured picture of the distribution of DNIC dissipated followed by a uniform green coloring of the solution caused by a uniform distribution of DNIC in it. It is assumed that the formation of autowaves is a consequence of the autooscillatory mode of the existence of a chemical system formed in a mixture of NO, low-molecular-weight thiols, and ferrous iron ions. DNIC with thiolate ligands and S-nitrosothiols arising in this system have a capacity for interconversion, and it is this process that may underlie the autooscillatory, autowave mode of functioning of the system. It is not ruled out that the existence of this system in cells and tissues of living organisms may provide the spatial and temporal organization of the regulation of the biological action of NO and its different endogenous compounds and derivatives.

  19. 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.

  20. Radioisotope trithiol complexes

    DOEpatents

    Jurisson, Silvia S.; Cutler, Cathy S.; Degraffenreid, Anthony J.

    2016-08-30

    The present invention is directed to a series of stable radioisotope trithiol complexes that provide a simplified route for the direct complexation of radioisotopes present in low concentrations. In certain embodiments, the complex contains a linking domain configured to conjugate the radioisotope trithiol complex to a targeting vector. The invention is also directed to a novel method of linking the radioisotope to a trithiol compound to form the radioisotope trithiol complex. The inventive radioisotope trithiol complexes may be utilized for a variety of applications, including diagnostics and/or treatment in nuclear medicine.

  1. Effect of freezing plasma at -20°C for 2 weeks on prothrombin time, activated partial thromboplastin time, dilute Russell viper venom time, activated protein C resistance, and D-dimer levels.

    PubMed

    Foshat, Michelle; Bates, Stephanie; Russo, Wendy; Huerta, Araceli; Albright, Kathleen; Giddings, Karen; Indrikovs, Alexander; Qian, You-Wen

    2015-01-01

    To assess the impact of preanalytical variables of time and temperature on prothrombin time (PT), activated partial thromboplastin time (aPTT), dilute Russell viper venom time (DRVVT), activated protein C resistance (APCR), and d-dimer, samples from 23 healthy individuals and 18 patients having coagulopathy with known abnormal PT and aPTT were collected. Plasma from each individual was separately pooled and aliquoted; the first 2 aliquots were stored at room temperature then analyzed at 2 hours (baseline) and 4 hours postcollection. The remaining aliquots were stored at -20°C and thawed for analysis at 48 hours, 1, and 2 weeks. In both healthy participants and participants with coagulopathy, PT, aPTT, APCR, DRVVT, and D-dimer had no significant changes at 4 and 48 hours, and 1 and 2 weeks postcollection compared to baseline, or the changes were less than 10%. The results indicate PT, aPTT, DRVVT, APCR, and d-dimer can be stored for 2 weeks at -20°C without compromising clinical interpretation in both healthy individuals and individuals with coagulopathy. Increasing storage time will facilitate sample processing from off-site clinics.

  2. Role of polymorphisms in factor V (FV Leiden), prothrombin, plasminogen activator inhibitor type-1 (PAI-1), methylenetetrahydrofolate reductase (MTHFR) and cystathionine β-synthase (CBS) genes as risk factors for thrombophilias.

    PubMed

    Miranda-Vilela, A L

    2012-09-01

    Thrombophilias are defined as a predisposition to thrombosis due to hematological changes which induce blood hypercoagulability; they can be inherited or acquired. They are individually characterized by a large phenotypic variability, even when they occur within the same family. Hereditary thrombophilias are, in most cases, due to changes related to physiological coagulation inhibitors or mutations in the genes of coagulation factors. High levels of plasma homocysteine may also be responsible for vaso-occlusive episodes and may have acquired (nutritional deficiencies of folate and vitamins B6 and B12) and/or genetic causes (mutations in the genes responsible for expression of enzymes involved in the intracellular metabolism of homocysteine). Considering that: (1) thromboses are events of multigenic and multifactorial etiopathology; (2) the presence of mutations in several genes significantly increases the risk of their occurrence; (3) the vascular territory (venous and/or arterial) affected involves different pathophysiological mechanisms and treatments, knowledge of genetic variants that may contribute to the risk and variability of the phenotypic manifestations of these diseases is extremely important. This understanding may provide support for a more individualized and therefore more effective treatment for thrombophilia carriers. Thus, this mini-review aims to address a comprehensive summary of thrombophilias and thrombosis, and discuss the role of polymorphisms in Factor V (FV Leiden), Prothrombin, Plasminogen activator inhibitor type-1 (PAI-1), Methylenetetrahydrofolate reductase (MTHFR) and Cystathionine β-synthase (CBS) genes as risk factors for thrombophilias.

  3. Pneumatic tube system transport does not alter platelet function in optical and whole blood aggregometry, prothrombin time, activated partial thromboplastin time, platelet count and fibrinogen in patients on anti-platelet drug therapy

    PubMed Central

    Enko, Dietmar; Mangge, Harald; Münch, Andreas; Niedrist, Tobias; Mahla, Elisabeth; Metzler, Helfried; Prüller, Florian

    2017-01-01

    Introduction The aim of this study was to assess pneumatic tube system (PTS) alteration on platelet function by the light transmission aggregometry (LTA) and whole blood aggregometry (WBA) method, and on the results of platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), and fibrinogen. Materials and methods Venous blood was collected into six 4.5 mL VACUETTE® 9NC coagulation sodium citrate 3.8% tubes (Greiner Bio-One International GmbH, Kremsmünster, Austria) from 49 intensive care unit (ICU) patients on dual anti-platelet therapy and immediately hand carried to the central laboratory. Blood samples were divided into 2 Groups: Group 1 samples (N = 49) underwent PTS (4 m/s) transport from the central laboratory to the distant laboratory and back to the central laboratory, whereas Group 2 samples (N = 49) were excluded from PTS forces. In both groups, LTA and WBA stimulated with collagen, adenosine-5’-diphosphate (ADP), arachidonic acid (AA) and thrombin-receptor-activated-peptide 6 (TRAP-6) as well as platelet count, PT, APTT, and fibrinogen were performed. Results No statistically significant differences were observed between blood samples with (Group 1) and without (Group 2) PTS transport (P values from 0.064 – 0.968). The AA-induced LTA (bias: 68.57%) exceeded the bias acceptance limit of ≤ 25%. Conclusions Blood sample transportation with computer controlled PTS in our hospital had no statistically significant effects on platelet aggregation determined in patients with anti-platelet therapy. Although AA induced LTA showed a significant bias, the diagnostic accuracy was not influenced. PMID:28392742

  4. The influence of factor V Leiden and G20210A prothrombin mutation on the presence of residual vein obstruction after idiopathic deep-vein thrombosis of the lower limbs.

    PubMed

    Cosmi, Benilde; Legnani, Cristina; Pengo, Vittorio; Ghirarduzzi, Angelo; Testa, Sophie; Poli, Daniela; Prisco, Domenico; Tripodi, Armando; Palareti, Gualtiero

    2013-03-01

    It was our aim to assess whether factor V Leiden (FVL) and G20210A prothrombin (FII) mutation are associated with the presence of residual vein obstruction (RVO) after a standard course of anticoagulation for a first episode of idiopathic proximal deep-vein thrombosis (DVT) of the lower limbs, with or without symptomatic pulmonary embolism (PE). Patients were enrolled in two prospective multicentre studies: PROLONG and PROLONG II. RVO was detected by compression ultrasonography according to the method of Prandoni on the day of anticoagulation withdrawal. Patients were also screened for FVL and FII mutation. The presence of FVL and/or FII mutation was determined in 872/963 (90.5%) patients, in 753 of whom RVO was assessed. FVL was significantly less frequent among subjects with isolated PE (7/176:4%) than among patients with either DVT and PE (15/133:11.3%; p=0.0018) or isolated DVT (89/563:15.8%; p<0.0001), confirming the FVL paradox. The rate of FII mutation was similar among patients with isolated PE (11/176:6.2%) and patients with either DVT and PE (12/133:9%) or isolated DVT (52/563:9.2%). FVL and FII mutation were not significantly associated with RVO at the multivariate analysis in all patients, although data suggest that FVL and FII mutation may have a differential effect on RVO in the subgroups of patients with DVT and DVT plus PE patients. Male sex and isolated DVT were significantly associated with RVO in all patients. In conclusion, male sex and isolated DVT are associated with RVO, while FVL and FII mutations are not significantly associated with RVO in this study.

  5. Fluctuating Concentrations in Atmospheric Dispersion

    NASA Astrophysics Data System (ADS)

    Devaull, George Ellis, III

    This thesis presents theoretical models and experimental results of average and instantaneous concentration measurements from a series of atmospheric dispersion experiments conducted under both unstable and stable meteorological conditions. The experiments were undertaken at two different sites, over both flat and gently rolling terrain. Two types of surface -level point aerosol sources were used. One is a fog-oil smoke and the other is a hexachloroethane chemical smoke. Measurements of concentration at points along crosswind transects were taken over time periods of an hour at distances to several kilometers from the source. These measurements included both aerosol photometer records of the instantaneous concentration taken at a 1 Hz sampling rate and aspirated filters for mean concentration measurements. The flat terrain site was located at Camp Atterbury, Indiana, while the gently rolling terrain site was near Red Bluff, California. Meteorological measurements at these sites included both tower measurements and upper -air balloon soundings. These measurements were used in determining the atmospheric boundary layer scaling parameters in the unstable tests and in characterizing the complex wind field for the stable tests. The data compare favorably with developed models for both the mean and variance in concentration. Concentration fluctuation intensity ranges from 2 near the plume centerline to greater than 20 at the plume edge. Intermittency is important at all locations, with positive concentrations recorded on the mean plume centerline only 20% to 50% of the time. Point concentration histograms are shown to agree with the exponential distribution for concentrations greater than zero. Spectra of the concentration data show an inertial -convective subrange with a -5/3 power law versus frequency behavior. Integral time scales of the concentration records at all individual sampling points are approximately constant within a test and are equal to the mean duration

  6. Successive Administration of Streptococcus Type 5 Group A Antigens and S. typhimurium Antigenic Complex Corrects Elevation of Serum Cytokine Concentration and Number of Bone Marrow Stromal Pluripotent Cells in CBA Mice Induced by Each Antigen Separately.

    PubMed

    Gorskaya, Yu F; Danilova, T A; Grabko, V I; Nesterenko, V G

    2015-12-01

    Administration of bacterial antigens to CBA mice induced an increase in serum concentration of virtually all cytokines with a peak in 4 h after administration of S. typhimurium antigens and in 7 h after administration of streptococcus antigens. In 20 h, cytokine concentrations returned to the control level or were slightly below it. In 4 h after administration of S. typhimurium antigens preceded 3 h before by administration of streptococcus antigens, we observed a significant decrease in serum concentrations of IFN-γ, IL-10, GM-CSF, IL-12, and TNF-α, in comparison with injection S. typhimurium antigens alone and IL-5, IL-10, GM-CSF, and TNF-α in comparison with injection of streptococcus antigens alone; the concentrations of IL-2 and IFN-γ, in contrast, increased by 1.5 times in this case. In 20 h after administration of S. typhimurium antigens, the number of multipotential stromal cells (MSC) in the bone marrow and their cloning efficiency (ECF-MSC) increased by 4.8 and 4.4 times, respectively, in comparison with the control, while after administration of streptococcus antigens by 2.6 and 2.4 times, respectively. In 20 h after administration of S. typhimurium antigens preceded 3 h before by administration of streptococcus antigens, these parameters increased by 3.2 and 2.9 times, respectively, in comparison with the control, i.e. the observed increase in the level of MSC count and ECF-MSC is more consistent with the response of the stromal tissue to streptococcus antigens. Thus, successive administration of two bacterial antigens corrected both serum cytokine profiles and MSC response to administration of each antigen separately, which indicates changeability of the stromal tissue in response to changes in the immune response.

  7. Thin solar concentrator with high concentration ratio

    NASA Astrophysics Data System (ADS)

    Lin, Jhe-Syuan; Liang, Chao-Wen

    2013-09-01

    Solar concentrators are often used in conjunction with III-V multi-junction solar cells for cost reduction and efficiency improvement purposes. High flux concentration ratio, high optical efficiency and high manufacture tolerance are the key features required for a successful solar concentrator design. This paper describes a novel solar concentrator that combines the concepts, and thus the advantages, of both the refractive type ad reflective type. The proposed concentrator design adopts the Etendue-cascading concept that allows the light beams from all the concentric annular entrance pupils to be collected and transferred to the solar cell with minimal loss. This concept enables the system to perform near its Etendue-Limit and have a high concentration ratio simultaneously. Thereby reducing the costs of solar cells and therefor achieves a better the per watts cost. The concentrator demonstrated has a thing aspect ratio of 0.19 with a zero back focal distance. The numerical aperture at the solar cell immersed inside the dielectric concentrator is as high as 1.33 achieving a unprecedented high optical concentration ratio design.

  8. Theoretical maximum concentration factors for solar concentrators

    SciTech Connect

    Nicolas, R.O.; Duran, J.C.

    1984-11-01

    The theoretical maximum concentration factors are determined for different definitions of the factor for two-dimensional and three-dimensional solar concentrators that are valid for any source with nonuniform intensity distribution. Results are obtained starting from those derived by Winston (1970) for Lambertian sources. In particular, maximum concentration factors for three models of the solar-disk intensity distribution are calculated. 12 references.

  9. 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

  10. Flat high concentration devices

    SciTech Connect

    Minano, J.C.; Gonzalez, J.C.; Zanesco, I.

    1994-12-31

    During the last five years new concentrators achieving the theoretical maximum acceptance-angle-concentration product have appeared. In addition, some of these concentrators are very compact (concentrator depth/aperture diameter smaller than 1/3). The feasibility of these concentrators for photovoltaic applications is studied. It is concluded that these concentrators may be useful for high concentration cells (irradiance for maximum efficiency greater than 800 suns) if these cells have a small size (diameter smaller than 5 mm). The concentrators may provide for this case an acceptance angle of {approx} {+-}2.7 degrees with concentration factor around 1,000x and a concentrator depth 10 times the cell diameter. Instantaneous direct insolation and ambient temperature measurements of Madrid and a thermal model of the heat sink is used to calculate the annual electric energy output with which different concentration factors are compared. Concentration of 1,000x is close to the one giving the maximum annual electrical output.

  11. 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

  12. 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

  13. 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.

  14. 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,…

  15. 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.

  16. Air Data - Concentration Map

    EPA Pesticide Factsheets

    Make a map of daily concentrations over several days. The daily air quality can be displayed in terms of the Air Quality Index or in concentration ranges for certain PM species like organic carbon, nitrates, and sulfates.

  17. 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.

  18. 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…

  19. Complex odontoma.

    PubMed

    Preetha, A; Balikai, Bharati S; Sujatha, D; Pai, Anuradha; Ganapathy, K S

    2010-01-01

    Odontomas are hamartomatous lesions or malformations composed of mature enamel, dentin, and pulp. They may be compound or complex, depending on the extent of morphodifferentiation or their resemblance to normal teeth. The etiology of odontoma is unknown, although several theories have been proposed. This article describes a case of a large infected complex odontoma in the residual mandibular ridge, resulting in considerable mandibular expansion.

  20. Photovoltaics. III - Concentrators

    NASA Astrophysics Data System (ADS)

    Backus, C. E.

    1980-02-01

    Photovoltaic concentration systems that redirect sunlight falling on a surface to a smaller solar-cell surface concentrating the intensity of sunlight many times are examined. It is noted that solar cells for concentrating systems must be designed for low internal resistance as well as for high sunlight intensities. Two designs of silicon cells are presented that perform well at high concentrations; these are interdigitated back-contact cells and vertical multijunction cells. Attention is given to heat tapping of reemitted light.

  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. Defining hormesis: evaluation of a complex concentration response phenomenon.

    PubMed

    Kendig, Eric L; Le, Hoa H; Belcher, Scott M

    2010-01-01

    Hormesis describes dose-response relationships characterized by a reversal of response between low and high doses of chemicals, biological molecules, physical stressors, or other initiators of a response. Acceptance of hormesis as a viable dose-response theory has been limited until recently, in part, because of poor conceptual understanding, ad hoc and inappropriate use, and lack of a defined mechanism. By examining the history of this dose-response theory, it is clear that both pharmacological and toxicological studies provide evidence for hormetic dose responses, but retrospective examination of studies can be problematic at best. Limited scientific evidence and lack of a common lexicon with which to describe these responses have left hormesis open to inappropriate application to unrelated dose-response relationships. Future studies should examine low-dose effects using unbiased, descriptive criteria to further the scientific understanding of this dose response. A clear, concise definition is required to further the limited scientific evidence for hormetic dose responses.

  3. Recent trends in concentrated photovoltaics concentrators' architecture

    NASA Astrophysics Data System (ADS)

    Buljan, Marina; Mendes-Lopes, João; Benítez, Pablo; Miñano, Juan Carlos

    2014-01-01

    The field of concentrated photovoltaics (CPV) has met some remarkable advances in recent years. The continuous increase in conversion efficiency of multijunction solar cells and new advancements in optics have led to new demands and opportunities for optical design in CPV. This paper is a mini-review on current requirements for CPV optical design, and it presents some of the main trends in recent years on CPV systems architecture.

  4. Effect of serum monoclonal protein concentration on haemostasis in patients with multiple myeloma.

    PubMed

    Huang, Heyu; Li, Huijun; Li, Dengju

    2015-07-01

    Abnormalities in haemostasis are often detected in patients with multiple myeloma and the fundamental factors that lead to these abnormities are worthy of exploration. The objective of this study was to investigate bleeding diathesis and coagulopathy in different multiple myeloma types or stages and assess how paraprotein concentration contributes to differences in these conditions. Haemostasis screening tests and serum monoclonal protein (M protein) concentration were retrospectively analysed in 101 patients newly diagnosed with multiple myeloma from January 2012 to April 2014. No significant differences were found between bleeding diathesis and types or International Staging System (ISS) stages of multiple myeloma; however, prolonged thrombin time (TT) was found in most of patients (77.7%) and was positively related to light-chain concentration (P ≤ 0.01). Prolonged prothrombin time (PT) was more obvious in IgA and IgG-type multiple myeloma than in the light-chain type (P ≤ 0.01). With increased clinical staging, PT remarkably increased (P ≤ 0.01). M protein concentration was significantly higher in patients with prolonged PT than in those with normal PT (P ≤ 0.01). The D-dimer mean was significantly higher than normal (>0.5 μg/ml) (P ≤ 0.01). Fibrinogen was negatively related to M protein levels (P ≤ 0.01); however, there was no correlation between activated partial thromboplastin time (APTT) and multiple myeloma stages or types, M protein levels and serum light-chain concentration (P ≥ 0.05). Patients with light-chain type multiple myeloma were more likely to have prolonged TT than patients with other types. M protein levels had an obvious effect on PT. Prolonged PT was more common in IgA and IgG-type multiple myeloma. Abnormal haemostasis test results are not always accompanied by clinically apparent haemostatic complications.

  5. 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.

  6. 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.

  7. Concentrating photovoltaic systems

    NASA Astrophysics Data System (ADS)

    Dupas, A.

    1982-11-01

    Various configurations for concentrating photovoltaic systems are described and their operating principles are explained. The effects of temperature and series resistance on system efficiency are discussed. As an example, the french family of photovoltaic concentrating systems, SOPHOCLE, is described. The SOPHOCLE family of generators is characterized by the use of a heliostat with altazimuth mounting and by the choice of medium concentration (C=45) by fresnel lenses on silicon cells.

  8. A network property necessary for concentration robustness

    PubMed Central

    Eloundou-Mbebi, Jeanne M. O.; Küken, Anika; Omranian, Nooshin; Kleessen, Sabrina; Neigenfind, Jost; Basler, Georg; Nikoloski, Zoran

    2016-01-01

    Maintenance of functionality of complex cellular networks and entire organisms exposed to environmental perturbations often depends on concentration robustness of the underlying components. Yet, the reasons and consequences of concentration robustness in large-scale cellular networks remain largely unknown. Here, we derive a necessary condition for concentration robustness based only on the structure of networks endowed with mass action kinetics. The structural condition can be used to design targeted experiments to study concentration robustness. We show that metabolites satisfying the necessary condition are present in metabolic networks from diverse species, suggesting prevalence of this property across kingdoms of life. We also demonstrate that our predictions about concentration robustness of energy-related metabolites are in line with experimental evidence from Escherichia coli. The necessary condition is applicable to mass action biological systems of arbitrary size, and will enable understanding the implications of concentration robustness in genetic engineering strategies and medical applications. PMID:27759015

  9. A network property necessary for concentration robustness

    NASA Astrophysics Data System (ADS)

    Eloundou-Mbebi, Jeanne M. O.; Küken, Anika; Omranian, Nooshin; Kleessen, Sabrina; Neigenfind, Jost; Basler, Georg; Nikoloski, Zoran

    2016-10-01

    Maintenance of functionality of complex cellular networks and entire organisms exposed to environmental perturbations often depends on concentration robustness of the underlying components. Yet, the reasons and consequences of concentration robustness in large-scale cellular networks remain largely unknown. Here, we derive a necessary condition for concentration robustness based only on the structure of networks endowed with mass action kinetics. The structural condition can be used to design targeted experiments to study concentration robustness. We show that metabolites satisfying the necessary condition are present in metabolic networks from diverse species, suggesting prevalence of this property across kingdoms of life. We also demonstrate that our predictions about concentration robustness of energy-related metabolites are in line with experimental evidence from Escherichia coli. The necessary condition is applicable to mass action biological systems of arbitrary size, and will enable understanding the implications of concentration robustness in genetic engineering strategies and medical applications.

  10. High concentration plasma-reduced plateletapheresis concentrates.

    PubMed

    Perseghin, Paolo

    2011-06-01

    Single-donor hyperconcentrated plateletapheresis (dry-platelets) collection has been introduced in the 90's as a part of the newly developed multi-component collection strategy. This approach allowed to safely collect multiple components from a single apheresis donation, i.e. RBC, FFP and/or plateletpheresis units. Dry-platelets are usually resuspended in additive solution to maintain an adequate pH during the storage period until use. Some concern existed about possible higher degrees of platelet activation in dry-platelets units when compared to standard concentration (1.0-1.6 × 10(6)/μL platelets) units and its possible correlation with lower in vivo efficiency and/or survival of the former units. Several authors investigated this specific issue, and dry-platelets units proved to be equally effective than standard concentration plateletpheresis units in recipients. The use of dry-platelets units may reduce (i) the risk of passive infusion of naturally occurring ABO-related hemolytic antibodies when donor O platelets are given to group A, B, or AB recipient, (ii) the risk of TRALI when multiparous donors undergo plateletpheresis. Furthermore, dry-platelet collection may allow for an increased amount of FFP sent to industry. Finally, hyperconcentrated platelet units may be used for "niche" indications, such as intrauterine platelet transfusion or, in case of autologous dry-platelet collection, for further freezing for long term storage in selected patients within onco-hematological settings.

  11. 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.

  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. 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 ... corner, the edge of the Antarctic coastline and some sea ice can be seen through some thin, high cirrus clouds. The right-hand panel ...

  14. 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…

  15. 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.

  16. Nebulization Reflux Concentrator

    NASA Technical Reports Server (NTRS)

    Cofer, Wesley R., III; Collins, V. G.

    1986-01-01

    Nebulization reflux concentrator extracts and concentrates trace quantities of water-soluble gases for subsequent chemical analysis. Hydrophobic membrane and nebulizing nozzles form scrubber for removing trace quantities of soluble gases or other contaminants from atmosphere. Although hydrophobic membrane virtually blocks all transport of droplets, it offers little resistance to gas flow; hence, device permits relatively large volumes of gas scrubbed efficiently with very small volumes of liquid. This means analyzable quantities of contaminants concentrate in extracting solutions in much shorter times than with conventional techniques.

  17. Concentrating photovoltaic solar panel

    DOEpatents

    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.

  18. Complex chemistry with complex compounds

    NASA Astrophysics Data System (ADS)

    Eichler, Robert; Asai, M.; Brand, H.; Chiera, N. M.; Di Nitto, A.; Dressler, R.; Düllmann, Ch. E.; Even, J.; Fangli, F.; Goetz, M.; Haba, H.; Hartmann, W.; Jäger, E.; Kaji, D.; Kanaya, J.; Kaneya, Y.; Khuyagbaatar, J.; Kindler, B.; Komori, Y.; Kraus, B.; Kratz, J. V.; Krier, J.; Kudou, Y.; Kurz, N.; Miyashita, S.; Morimoto, K.; Morita, K.; Murakami, M.; Nagame, Y.; Ooe, K.; Piguet, D.; Sato, N.; Sato, T. K.; Steiner, J.; Steinegger, P.; Sumita, T.; Takeyama, M.; Tanaka, K.; Tomitsuka, T.; Toyoshima, A.; Tsukada, K.; Türler, A.; Usoltsev, I.; Wakabayashi, Y.; Wang, Y.; Wiehl, N.; Wittwer, Y.; Yakushev, A.; Yamaki, S.; Yano, S.; Yamaki, S.; Qin, Z.

    2016-12-01

    In recent years gas-phase chemical studies assisted by physical pre-separation allowed for the investigation of fragile single molecular species by gas-phase chromatography. The latest success with the heaviest group 6 transactinide seaborgium is highlighted. The formation of a very volatile hexacarbonyl compound Sg(CO)6 was observed similarly to its lighter homologues molybdenum and tungsten. The interactions of these gaseous carbonyl complex compounds with quartz surfaces were investigated by thermochromatography. Second-generation experiments are under way to investigate the intramolecular bond between the central metal atom of the complexes and the ligands addressing the influence of relativistic effects in the heaviest compounds. Our contribution comprises some aspects of the ongoing challenging experiments as well as an outlook towards other interesting compounds related to volatile complex compounds in the gas phase.

  19. 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.

  20. 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

  1. High concentration dust monitor

    NASA Astrophysics Data System (ADS)

    Lilienfeld, P.

    1981-06-01

    The development, design, fabrication, and testing of a portable, self-contained prototype monitoring instrument capable of detecting and measuring airborne coal dust levels as concentrations in the range of 20 to 500 g/cu m is described. The output of the high concentration dust monitor is essentially independent of particle size and composition, with a response time of 10 seconds. Direct concentration readout as well as internal memory or recording capabilities are incorporated in the device. The operation of the instrument is based on direct sensing of the mass concentration of airborne dust by air-path beta radiation attenuation. The monitor is battery operated and incorporates a microprocessor that controls periodic automatic zero referencing, executes the mass computations, records the data for subsequent playback, and performs internal diagnostic checks.

  2. Water Sample Concentrator

    ScienceCinema

    Idaho National Laboratory

    2016-07-12

    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

  3. Roles of factor Va heavy and light chains in protein and lipid rearrangements associated with the formation of a bovine factor Va-membrane complex.

    PubMed Central

    Koppaka, V; Talbot, W F; Zhai, X; Lentz, B R

    1997-01-01

    Factor Va is an essential protein cofactor of the enzyme factor Xa, which activates prothrombin to thrombin during blood coagulation. Peptides with an apparent Mr of approximately 94,000 (heavy chain; HC) and approximately 74,000 or 72,000 (light chain; LC) interact in the presence of Ca2+ to form active Va. The two forms of Va-LC differ in their carboxyl-terminal C2 domain. Using Va reconstituted with either LC form, we examined the effects of the two LC species on membrane binding and on the activity of membrane-bound Va. We found that 1) Va composed of the 72,000 LC bound only slightly more tightly to membranes composed of a mixture of neutral and acidic lipids, the Kd being reduced by a factor of approximately 3 at 5 mM and by a factor of 6 at 2 mM Ca2+. 2) The two forms of Va seemed to undergo different conformational changes when bound to a membrane. 3) The activity of bovine Va varied somewhat with LC species, the difference being greatest at limiting Xa concentration. We have also addressed the role of the two Va peptides in membrane lipid rearrangements and binding: 1) Va binding increased lateral packing density in mixed neutral/acidic lipid membranes. In the solid phase, Va-HC had no effect, whereas Va-LC and whole Va had similar but small effects. In the fluid phase, Va-HC and whole Va both altered membrane packing, with Va-HC having the largest effect. 2) Va-HC bound reversibly and in a Ca2+-independent fashion to membranes composed of neutral phospholipid (Kd, approximately 0.3 microM; stoichiometry approximately 91). High ionic strength had little effect on binding. 3) The substantial effect of Va on packing within neutral phospholipid membranes was mimicked by Va-HC. 4) Based on measurements of membrane phase behavior, binding of Va or its peptide components did not induce thermodynamically discernible lateral membrane domains. These results suggest that the membrane association of factor Va is a complex process involving both chains of Va, changes

  4. Joined concentric tubes

    DOEpatents

    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. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Concentrating photovoltaic technology

    SciTech Connect

    Edenburn, M.W.

    1984-01-01

    This paper will summarize the status and discuss likely future directions of photovoltaic concentrator technology. A current commercial Si cell module has a peak efficiency of 15.5%, and 17% has been reached with an experimental module. Advanced cells and module design improvements offer still higher efficiencies. Concentrator Fresnel lens array fields installed several years ago have all demonstrated very good electrical performance with little performance degradation. Fresnel lens arrays were commercially available and prices of $7/watt for installed one megawatt systems have been quoted. Cost projections predict that current technology concentrating PV arrays can be installed for less than $2/watt if they are manufactured in large, steady quantities. More advanced designs may cost even less.

  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. 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.

  17. 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

  18. Solar concentrator/absorber

    NASA Technical Reports Server (NTRS)

    Von Tiesenhausen, G. F.

    1976-01-01

    Collector/energy converter, consisting of dual-slope optical concentrator and counterflow thermal energy absorber, is attached to multiaxis support structure. Efficient over wide range of illumination levels, device may be used to generate high temperature steam, serve as solar powered dryer, or power absorption cycle cooler.

  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. 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

  1. 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.

  2. Cyclindrical concentrators as a limit case of torodial concentrators

    SciTech Connect

    Minano, J.C.

    1984-06-15

    Cylindrical concentrators are viewed as a limit case of torodial concentrators with the purpose of applying to them some results obtained for axisymmetrical optical systems. This enables us to obtain easily the directional intercept factor of a cyclindrical nonimaging concentrator called the Ideal Tubular Concentrator. A useful tool for designing new cylindrical concentrators is also derived.

  3. New types of lanthanide complexes

    SciTech Connect

    Kahwa, I.A.K.

    1986-01-01

    Three new types of lanthanide (Ln) complexes, namely, the first examples of homodinuclear macrocyclic lanthanide complexes, novel binary and ternary gaseous polyatomic lanthanide oxides and new lanthanide oxalato complexes are described in chapters one, two and three respectively. The homodinuclear complexes are 2:2 condensation products of 2,6-diformyl-p-cresol and triethylenetetramine templated by Ln(NO/sub 3/)/sub 3/ and Ln(ClO/sub 4/)/sub 3/. The complexes are dimorphic, and are off-white (the more stable form) when they are obtained from dilute solutions and orange if they arise from more concentrated reactants. The complexes were characterized by elemental analysis, fast atom bombardment mass spectrometry (FAB MS), electronic absorption and IR spectroscopy, thermogravimetry along with preliminary spectroscopic studies using electron paramagnetic resonance, magnetic susceptibility and luminescence. The orange complexes exhibit more antiferromagnetic exchange interactions, low Ln/sup 3 +/magnetic moments and multi-exponential luminescence decay kinetics, whereas the off-white complexes show single exponential luminescence decay and free ion magnetic moments. At low temperatures and in presence of excess triethylenetetramine, solvated light lanthanide mononuclear complexes of a 1:1 acyclic Schiff base acetal were isolated and the structure of one of these was confirmed by single crystal x-ray diffraction crystallography.

  4. 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.

  5. Concentration of 68Ga via solvent extraction.

    PubMed

    Bokhari, Tanveer Hussain; Mushtaq, A; Khan, Islam Ullah

    2009-01-01

    The metallic cation, (68)Ga (III) is suitable for complexation with chelators either naked or conjugated with biological macromolecules, however, such labeling procedure requires high chemical purity and concentrated solutions of (68)Ga (III), which cannot be sufficiently fulfilled by the presently available (68)Ge/(68)Ga generator eluate. A method to increase the concentration and purity of (68)Ga obtained from a commercial (68)Ge/(68)Ga generator has been developed. The (68)Ga eluate (1M HCl) is extracted in methyl ethyl ketone, which is evaporated and taken in a small volume of buffer.

  6. 78 FR 9055 - National Center for Health Statistics (NCHS), Classifications and Public Health Data Standards...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-07

    ... be Discussed: Agenda items include: ] March 5, 2013 ICD-9-CM Topics Infusion of Prothrombin Complex Concentrate Transprostatic Guided Implantable Struts ICD-10 Topics ICD-10 Implementation Announcements ICD-10... Struts ICD-10 HAC Translations ICD-10-PCS Addendum ICD-10-CM Diagnosis Topics Complications of...

  7. 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.

  8. 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.

  9. 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.

  10. Modeling of concentrated suspensions

    NASA Astrophysics Data System (ADS)

    van den Brule, B. H. A. A.; Jongschaap, R. J. J.

    1991-03-01

    The constitutive equation of a concentrated suspension of spherical particles in a Newtonian medium is derived. To this end the method of local volume averaging is employed. To calculate the contribution of the particles to the stress tensor it is assumed that the stress generated in the interstitial holes between the particles is negligible compared to the stress generated in !he narrow gaps separating the particles. The use of the resulting expression is demonstrated with two examples on a cubical arrangement of particles: pure shear and simple shear. Furthermore, the validity of the lubrication approximation employed in this work is checked against the results derived by Nunan and Keller for periodic suspensions.

  11. Concentric Loop Surface Coil

    NASA Astrophysics Data System (ADS)

    Hernández-Flores, R.; Rodríguez-González, A. O.; Salgado-Lujambio, P.; Barrios-Alvarez, F. A.

    2002-08-01

    A surface coil for MRI consisted of two concentric loops was developed for brain imaging. Prior to build the coil prototype, the magnetic field (B1) generated by the coil was numerically simulated. This field simulation is based on the Biot-Savart law for the circular- and square-shaped loops. From these theoretical results, we can appreciate an improvement on the B1 homogeneity. Brain images obtained at 1.5 Tesla show a good sensitivity in a particular region of interest. Also, these images compared well against images obtained with a circular-shaped coil. This receiver coil can generate high quality brain images.

  12. Fixed solar energy concentrator

    SciTech Connect

    Houghton, A.J.; Knasel, T.M.

    1981-01-20

    An apparatus for the concentration of solar energy upon a fixed array of solar cells is disclosed. A transparent material is overlayed upon the cell array, and a diffuse reflective coating is applied to the surface area of the transparent medium in between cells. Radiant light, which reflects through the transparent layer and does not fall directly incident to a cell surface is reflected by the coating layer in an approximate cosine pattern. Thereafter, such light undergoes internal reflection and rediffusion until subsequently it either strikes a solar cell surface or is lost through the upper surface of the transparent material.

  13. Concentric layer ramjet fuel

    SciTech Connect

    Burdette, G.W.; Francis, J.P.

    1988-03-08

    This patent describes a solid fuel ramjet grain comprising concentric layers of solid ramjet fuel having a perforation therethrough along the center axis of the grain. The performation is connected to a combustion after-chamber. The solid ramjet fuel layers comprises a pure hydroxyl-terminated polybutadiene hydrocarbon fuel or a mixture of a hydroxyl-terminated polybutadiene hydrocarbon fuel and from about 5 to about 60 percent by weight of an additive to increase the fuel regression rate selected from the group consisting of magnesium, boron carbide, aluminum, and zirconium such that, when buried in the operation of the ramjet, each fuel layer produces a different level of thrust.

  14. 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.

  15. 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.

  16. Benchmarking concentrating photovoltaic systems

    NASA Astrophysics Data System (ADS)

    Duerr, Fabian; Muthirayan, Buvaneshwari; Meuret, Youri; Thienpont, Hugo

    2010-08-01

    Integral to photovoltaics is the need to provide improved economic viability. To achieve this goal, photovoltaic technology has to be able to harness more light at less cost. A large variety of concentrating photovoltaic concepts has provided cause for pursuit. To obtain a detailed profitability analysis, a flexible evaluation is crucial for benchmarking the cost-performance of this variety of concentrating photovoltaic concepts. To save time and capital, a way to estimate the cost-performance of a complete solar energy system is to use computer aided modeling. In this work a benchmark tool is introduced based on a modular programming concept. The overall implementation is done in MATLAB whereas Advanced Systems Analysis Program (ASAP) is used for ray tracing calculations. This allows for a flexible and extendable structuring of all important modules, namely an advanced source modeling including time and local dependence, and an advanced optical system analysis of various optical designs to obtain an evaluation of the figure of merit. An important figure of merit: the energy yield for a given photovoltaic system at a geographical position over a specific period, can be calculated.

  17. 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.

  18. 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.

  19. Resveratrol protects against experimental induced Reye's syndrome by prohibition of oxidative stress and restoration of complex I activity.

    PubMed

    Abdin, Amany; Sarhan, Naglaa

    2014-09-01

    This study was designed to investigate whether resveratrol could provide protection against Reye's syndrome induced by 4-pentenoic acid in Wistar albino rats. Compared with rats with untreated Reye's syndrome, 1 h pretreatment by low dose resveratrol (10 mg/kg by oral gavage) resulted in marked amelioration in liver functions in the form of significant decrease in serum transaminases (AST, ALT) and plasma ammonia levels, shortening of prothrombin time, and increase in serum albumin levels. In addition, resveratrol prohibited oxidative stress markers, as indicated by a significant increase in GSH and decrease in MDA, with restoration of complex I activity in liver tissues. The classical histopathological presentation in Reye's syndrome of microvesicular steatosis by light microscope and mitochondria distortion by electron microscope has been improved by resveratrol pretreatment. The efficient protection by resveratrol was determined by normalization in serum levels of AST and albumin, as well as complex I activity, GSH, and MDA. In conclusion, pretreatment by resveratrol in low doses could protect against Reye's syndrome partially via prohibition of oxidative stress and restoration of complex I activity. This may provide the opportunity to reconsider aspirin therapy for infants and young children. However, the verification of such results in clinical practice remains a challenge.

  20. 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.

  1. 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

  2. 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.

  3. 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.

  4. 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

  5. Effects of Fibrinogen Concentrate on Thrombin Generation, Thromboelastometry Parameters, and Laboratory Coagulation Testing in a 24-Hour Porcine Trauma Model

    PubMed Central

    Zentai, Christian; Solomon, Cristina; van der Meijden, Paola E. J.; Spronk, Henri M. H.; Schnabel, Jonas; Rossaint, Rolf

    2015-01-01

    Introduction: In a 24-hour porcine model of liver injury, we showed that fibrinogen supplementation does not downregulate endogenous fibrinogen synthesis. Here we report data from the same study showing the impact of fibrinogen on coagulation variables. Materials and Methods: Coagulopathy was induced in 20 German land race pigs by hemodilution and blunt liver injury. Animals randomly received fibrinogen concentrate (100 mg/kg) or saline. Coagulation parameters were assessed and thromboelastometry (ROTEM) was performed. Results: Fibrinogen concentrate significantly reduced the prolongations of EXTEM clotting time, EXTEM clot formation time, and prothrombin time induced by hemodilution and liver injury. A decrease in clot strength was also ameliorated. Endogenous thrombin potential was significantly higher in the fibrinogen group than in the control group, 20 minutes (353 ± 24 vs 289 ± 22 nmol/L·min; P < .05) and 100 minutes (315 ± 40 vs 263 ± 38 nmol/L·min; P < .05) after the start of infusion. However, no significant between-group differences were seen in other thrombin generation parameters or in d-dimer or thrombin–antithrombin levels. Fibrinogen–platelet binding was reduced following liver injury, with no significant differences between groups. No significant between-group differences were observed in any parameter at ∼12 and ∼24 hours. Conclusion: This study suggests that, in trauma, fibrinogen supplementation may shorten some measurements of the speed of coagulation initiation and produce a short-lived increase in endogenous thrombin potential, potentially through increased clotting substrate availability. Approximately 12 and 24 hours after starting fibrinogen concentrate/saline infusion, all parameters measured in this study were comparable in the 2 study groups. PMID:25948634

  6. 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

  7. 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.

  8. 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,…

  9. Concentration of Swiss Elite Orienteers.

    ERIC Educational Resources Information Center

    Seiler, Roland; Wetzel, Jorg

    1997-01-01

    A visual discrimination task was used to measure concentration among 43 members of Swiss national orienteering teams. Subjects were above average in the number of target objects dealt with and in duration of continuous concentration. For females only, ranking in orienteering performance was related to quality of concentration (ratio of correct to…

  10. Complex Fluids and Hydraulic Fracturing.

    PubMed

    Barbati, Alexander C; Desroches, Jean; Robisson, Agathe; McKinley, Gareth H

    2016-06-07

    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.

  11. High-efficiency solar concentrator

    NASA Technical Reports Server (NTRS)

    Lansing, F. L.; Dorman, J.

    1976-01-01

    A new type of solar concentrator is presented using liquid lenses and simple translational tracking mechanism. The concentrator achieves a 100:1 nominal concentration ratio and is compared in performance with a flat-plate collector having two sheets of glazing and non-selective coating. The results of the thermal analysis show that higher temperatures can be obtained with the concentrator than is possible with the non-concentrator flat-plate type. Furthermore, the thermal efficiency far exceeds that of the comparative flat-plate type for all operating conditions.

  12. High-efficiency solar concentrator

    NASA Technical Reports Server (NTRS)

    Lansing, F. L.; Dorman, J.

    1980-01-01

    A new type of solar concentrator is presented using liquid lenses and simple translational tracking mechanism. The concentrator achieves a 100:1 nominal concentration ratio and is compared in performance with a flat-plate collector having two sheets of glazing and non-selective coating. The results of the thermal analysis show that higher temperatures can be obtained with the concentrator than is possible with the non-concentrator flat-plate type. Furthermore, the thermal efficiency far exceeds that of the comparative flat-plate type for all operating conditions.

  13. Learning Boolean functions with concentrated spectra

    NASA Astrophysics Data System (ADS)

    Mixon, Dustin G.; Peterson, Jesse

    2015-08-01

    This paper discusses the theory and application of learning Boolean functions that are concentrated in the Fourier domain. We first estimate the VC dimension of this function class in order to establish a small sample complexity of learning in this case. Next, we propose a computationally efficient method of empirical risk minimization, and we apply this method to the MNIST database of handwritten digits. These results demonstrate the effectiveness of our model for modern classification tasks. We conclude with a list of open problems for future investigation.

  14. 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.

  15. Optical assessment of nonimaging concentrators.

    PubMed

    Timinger, A; Kribus, A; Ries, H; Smith, T; Walther, M

    2000-11-01

    An optical measurement method for nonimaging radiation concentrators is proposed. A Lambertian light source is placed in the exit aperture of the concentrator. Looking into the concentrator's entrance aperture from a remote position, one can photograph the transmission patterns. The patterns show the transmission of radiation through the concentrator with the full resolution of the four-dimensional phase space of geometric optics. By matching ray-tracing simulations to the measurement, one can achieve detailed and accurate information about the geometry of the concentrator. This is a remote, noncontact measurement and can be performed in situ for installed concentrators. Additional information regarding small-scale reflector waviness and surface reflectivity can also be obtained from the same measurement with additional analysis.

  16. Natural complexity, computational complexity and depth.

    PubMed

    Machta, J

    2011-09-01

    Depth is a complexity measure for natural systems of the kind studied in statistical physics and is defined in terms of computational complexity. Depth quantifies the length of the shortest parallel computation required to construct a typical system state or history starting from simple initial conditions. The properties of depth are discussed and it is compared with other complexity measures. Depth can only be large for systems with embedded computation.

  17. Continuous flow dielectrophoretic particle concentrator

    SciTech Connect

    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.

  18. 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.

  19. [Complexity of land ecosystem].

    PubMed

    Wu, Cifang; Chen, Meiqiu

    2002-06-01

    In recent years, complexity studies has become a new research region and been widely applied in engineering, biology, economy, management, military, police and sociology. In this paper, from the view of complex science, the main complexity characteristics of land ecosystem were described, furthermore, the application of fractal, chaos, and artificial neural network on the complexity of land ecosystem were also discussed.

  20. Point Defect Concentrations in Metastable Fe-C Alloys

    SciTech Connect

    Foerst, Clemens J.; Yip, Sidney; Slycke, Jan; Vliet, Krystyn J. van

    2006-05-05

    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.

  1. 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

  2. Optimal concentrations in transport systems.

    PubMed

    Jensen, Kaare H; Kim, Wonjung; Holbrook, N Michele; Bush, John W M

    2013-06-06

    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 2(α)μ0, 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.

  3. 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.

  4. MODELING INDOOR CONCENTRATIONS AND EXPOSURE

    EPA Science Inventory

    The paper discusses the use of an indoor air quality model, EXPOSURE, to predict pollutant concentrations and exposures. The effects of indoor air pollutants depend on the concentrations of the pollutants and the exposure of individuals to the pollutants. The air pollutant concen...

  5. 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.

  6. 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.

  7. The complex chemical Langevin equation.

    PubMed

    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.

  8. Global gene expression analysis reveals pathway differences between teratogenic and non-teratogenic exposure concentrations of bisphenol A and 17β-estradiol in embryonic zebrafish

    PubMed Central

    Saili, Katerine S.; Tilton, Susan C.; Waters, Katrina M.; Tanguay, Robert L.

    2013-01-01

    Transient developmental exposure to 0.1 μM bisphenol A (BPA) results in larval zebrafish hyperactivity and learning impairments in the adult, while exposure to 80 μM BPA results in teratogenic responses, including craniofacial abnormalities and edema. The mode of action underlying these effects is unclear. We used global gene expression analysis to identify candidate genes and signaling pathways that mediate BPA’s developmental toxicity in zebrafish. Exposure concentrations were selected and anchored to the positive control, 17β-estradiol (E2), based on previously determined behavioral or teratogenic phenotypes. Functional analysis of differentially expressed genes revealed distinct expression profiles at 24 hours post fertilization for 0.1 versus 80 μM BPA and 0.1 versus 15 μM E2 exposure, identification of prothrombin activation as a top canonical pathway impacted by both 0.1 μM BPA and 0.1 μM E2 exposure, and suppressed expression of several genes involved in nervous system development and function following 0.1 μM BPAexposure. PMID:23557687

  9. Structural Studies of Protein-Surfactant Complexes

    SciTech Connect

    Chodankar, S. N.; Aswal, V. K.; Wagh, A. G.

    2008-03-17

    The structure of protein-surfactant complexes of two proteins bovine serum albumin (BSA) and lysozyme in presence of anionic surfactant sodium dodecyl sulfate (SDS) has been studied using small-angle neutron scattering (SANS). It is observed that these two proteins form different complex structures with the surfactant. While BSA protein undergoes unfolding on addition of surfactant, lysozyme does not show any unfolding even up to very high surfactant concentrations. The unfolding of BSA protein is caused by micelle-like aggregation of surfactant molecules in the complex. On the other hand, for lysozyme protein there is only binding of individual surfactant molecules to protein. Lysozyme in presence of higher surfactant concentrations has protein-surfactant complex structure coexisting with pure surfactant micelles.

  10. Droplet evaporation with complexity of evaporation modes

    NASA Astrophysics Data System (ADS)

    Hwang, In Gyu; Kim, Jin Young; Weon, Byung Mook

    2017-01-01

    Evaporation of a sessile droplet often exhibits a mixed evaporation mode, where the contact radius and the contact angle simultaneously vary with time. For sessile water droplets containing polymers with different initial polymer concentrations, we experimentally study their evaporation dynamics by measuring mass and volume changes. We show how diffusion-limited evaporation governs droplet evaporation, regardless of the complexity of evaporation behavior, and how the evaporation rate depends on the polymer concentration. Finally, we suggest a unified expression for a diffusion-limited evaporation rate for a sessile droplet with complexity in evaporation dynamics.

  11. 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.

  12. Complex networks analysis of language complexity

    NASA Astrophysics Data System (ADS)

    Amancio, Diego R.; Aluisio, Sandra M.; Oliveira, Osvaldo N., Jr.; Costa, Luciano da F.

    2012-12-01

    Methods from statistical physics, such as those involving complex networks, have been increasingly used in the quantitative analysis of linguistic phenomena. In this paper, we represented pieces of text with different levels of simplification in co-occurrence networks and found that topological regularity correlated negatively with textual complexity. Furthermore, in less complex texts the distance between concepts, represented as nodes, tended to decrease. The complex networks metrics were treated with multivariate pattern recognition techniques, which allowed us to distinguish between original texts and their simplified versions. For each original text, two simplified versions were generated manually with increasing number of simplification operations. As expected, distinction was easier for the strongly simplified versions, where the most relevant metrics were node strength, shortest paths and diversity. Also, the discrimination of complex texts was improved with higher hierarchical network metrics, thus pointing to the usefulness of considering wider contexts around the concepts. Though the accuracy rate in the distinction was not as high as in methods using deep linguistic knowledge, the complex network approach is still useful for a rapid screening of texts whenever assessing complexity is essential to guarantee accessibility to readers with limited reading ability.

  13. 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.

  14. 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.

  15. 21 CFR 864.7750 - Prothrombin time test.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... involves the reaction between coagulation factors III and VII, and to monitor patients receiving coumarin therapy (the administration of one of the coumarin anticoagulants in the treatment of venous thrombosis...

  16. 21 CFR 864.7750 - Prothrombin time test.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... involves the reaction between coagulation factors III and VII, and to monitor patients receiving coumarin therapy (the administration of one of the coumarin anticoagulants in the treatment of venous thrombosis...

  17. 21 CFR 864.7750 - Prothrombin time test.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... involves the reaction between coagulation factors III and VII, and to monitor patients receiving coumarin therapy (the administration of one of the coumarin anticoagulants in the treatment of venous thrombosis...

  18. 21 CFR 864.7750 - Prothrombin time test.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... involves the reaction between coagulation factors III and VII, and to monitor patients receiving coumarin therapy (the administration of one of the coumarin anticoagulants in the treatment of venous thrombosis...

  19. 21 CFR 864.7750 - Prothrombin time test.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... involves the reaction between coagulation factors III and VII, and to monitor patients receiving coumarin therapy (the administration of one of the coumarin anticoagulants in the treatment of venous thrombosis...

  20. 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)

  1. Evolution of biological complexity

    PubMed Central

    Adami, Christoph; Ofria, Charles; Collier, Travis C.

    2000-01-01

    To make a case for or against a trend in the evolution of complexity in biological evolution, complexity needs to be both rigorously defined and measurable. A recent information-theoretic (but intuitively evident) definition identifies genomic complexity with the amount of information a sequence stores about its environment. We investigate the evolution of genomic complexity in populations of digital organisms and monitor in detail the evolutionary transitions that increase complexity. We show that, because natural selection forces genomes to behave as a natural “Maxwell Demon,” within a fixed environment, genomic complexity is forced to increase. PMID:10781045

  2. Mitragynine concentrations in two fatalities.

    PubMed

    Domingo, Olwen; Roider, Gabriele; Stöver, Andreas; Graw, Matthias; Musshoff, Frank; Sachs, Hans; Bicker, Wolfgang

    2017-02-01

    Two cases of fatalities are reported of which the recreational use of Mitragyna speciosa ("kratom") could be confirmed. One of these cases presents with one of the highest postmortem mitragynine concentrations published to date. Our results show that even extremely high mitragynine blood concentrations following the consumption of kratom do not necessarily have to be the direct cause of death in such fatalities as a result of an acute overdose. The two cases are compared with regard to the differences in mitragynine concentrations detected and the role of mitragynine in the death of the subjects. Irrespective of the big differences in mitragynine concentrations in the postmortem blood samples, mitragynine was not the primary cause of death in either of the two cases reported here. Additionally, by rough estimation, a significant difference in ratio of mitragynine to its diastereomers in the blood and urine samples between the two cases could be seen.

  3. 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.

  4. 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.

  5. 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

  6. Luminescent solar concentrators: Semiconductor solution

    NASA Astrophysics Data System (ADS)

    Debije, Michael

    2017-03-01

    Reabsorption losses have long been holding back the commercial viability of luminescent solar concentrators. Now, non-toxic silicon-based quantum dots with enhanced Stokes shift may enable the technology to enjoy practical implementation.

  7. 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.

  8. Thin film concentrator panel development

    NASA Technical Reports Server (NTRS)

    Zimmerman, D. K.

    1982-01-01

    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.

  9. 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.

  10. Postmortem distribution of trazodone concentrations.

    PubMed

    McIntyre, Iain M; Mallett, Phyllis; Stabley, Robert

    2015-06-01

    Non-toxic postmortem trazodone tissue (liver) concentrations have not been previously described. Liver trazodone concentrations were compared to peripheral blood and central blood concentrations in 19 medical examiner cases. Postmortem blood specimens were initially screened for alcohol and simple volatiles, drugs of abuse, and alkaline drugs. Trazodone, when detected by the alkaline drug screen, was subsequently confirmed and quantified by a high performance liquid chromatography procedure. Re-analyses showed that there may be degradation of trazodone in postmortem blood stored at 4°C. There was, on average, about a 20% decrease in samples stored up to eight months. These data suggest that postmortem trazodone peripheral blood concentrations may be considered non-toxic to at least 1.0mg/L with liver concentrations to at least 2.2mg/kg. Overall, trazodone concentrations ranged from 0.08-6.1mg/L in peripheral blood, 0.07-7.1mg/L in central blood, and 0.39-26mg/kg in liver. The median trazodone central blood to peripheral blood ratio was 0.98 (N=19). The liver to peripheral blood ratios showed a median value of 2.8L/kg (N=18). Given that a liver to peripheral blood ratio less than 5L/kg is consistent with little to no propensity for postmortem redistribution, these data demonstrate that trazodone is unlikely to show significant redistribution.

  11. Radon concentration monitoring using xenon gamma-ray spectrometer

    NASA Astrophysics Data System (ADS)

    Novikov, A.; Ulin, S.; Dmitrenko, V.; Chernysheva, I.; Grachev, V.; Vlasik, K.; Uteshev, Z.; Shustov, A.; Petrenko, D.; Bychkova, O.

    2017-01-01

    A method for 222Rn concentration monitoring by means of intensity measurement of its daughter nuclei (214Pb and 214Bi) gamma-ray emission using xenon gamma-ray spectrometer is presented. Testing and calibration results for a gamma-spectrometric complex based on xenon gamma-ray detector are described.

  12. Photoresponsive Supramolecular Complexes as Efficient DNA Regulator

    PubMed Central

    Cheng, Hong-Bo; Zhang, Ying-Ming; Xu, Chao; Liu, Yu

    2014-01-01

    Two supramolecular complexes of trans-1⊂CB[8] and trans-2⊂CB[8] were successfully achieved by the controlled selective complexation process of cucurbit[8]uril (CB[8]) with hetero-guest pair containing azobenzene and bispyridinium moieties in aqueous solution, exhibiting the reversibly light-driven movements of CB[8] upon the photocontrollable isomerization of azophenyl axle components. Significantly, the obtained bistable supramolecular complexes and their corresponding [2]pseudorotaxanes could act as a promising concentrator and cleavage agent to regulate the binding behaviors with DNA molecules. PMID:24572680

  13. 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 ( ...

  14. 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 ...

  15. Irinotecan Lipid Complex Injection

    MedlinePlus

    Irinotecan lipid complex is used in combination with other medications to treat pancreatic cancer that has spread to other ... worsened after treatment with other chemotherapy medications. Irinotecan lipid complex is in a class of antineoplastic medications ...

  16. 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.

  17. Vincristine Lipid Complex Injection

    MedlinePlus

    Vincristine lipid complex is used to treat a certain type of acute lymphoblastic leukemia (ALL; a type ... at least two different treatments with other medications. Vincristine lipid complex is in a class of medications ...

  18. 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.

  19. Structure of nucleosome-HMG complexes

    SciTech Connect

    Paton, A.E.

    1982-12-01

    This dissertation concentrates on the structure of HMG-nucleosome complexes, and how they differ from nucleosomes alone. The first chapter provides an introduction to chromatin and an overview of the field. The second and third chapters describe what kinds of nucleosome-HMG protein complexes form in solution, and where the HMG proteins may bind on the nucleosome. A model is proposed that locates the HMG binding sites on the nucleosome core particle. The fourth chapter describes the biophysical characterization of the complex. The methods include thermal denaturation, circular dichroism and sedimentation velocity, all done under variety of solvent conditions. These methods reveal a great deal of information on the stability and interactions of the complex. The fifth chapter describes conformational probes of the complex. These results reveal the structural transitions that occur when HMG protein binds to the nucleosome as well as the parts of the nucleosome essential for the binding reaction.

  20. Metal Complexes of Diisopropylthiourea: Synthesis, Characterization and Antibacterial Studies

    PubMed Central

    Ajibade, Peter A.; Zulu, Nonkululeko H.

    2011-01-01

    Co(II), Cu(II), Zn(II) and Fe(III) complexes of diisopropylthiourea have been synthesized and characterized by elemental analyses, molar conductivity, magnetic susceptibility, FTIR and electronic spectroscopy. The compounds are non-electrolytes in solution and spectroscopic data of the complexes are consistent with 4-coordinate geometry for the metal(II) complexes and six coordinate octahedral for Fe(III) complex. The complexes were screened for their antibacterial activities against six bacteria: Escherichia coli, Pseudomonas auriginosa, Klebsiella pneumoniae, Bacillus cereus, Staphylococcus aureus and Bacillus pumilus. The complexes showed varied antibacterial activities and their minimum inhibitory concentrations (MICs) were determined. PMID:22072941

  1. Metal complexes of diisopropylthiourea: synthesis, characterization and antibacterial studies.

    PubMed

    Ajibade, Peter A; Zulu, Nonkululeko H

    2011-01-01

    Co(II), Cu(II), Zn(II) and Fe(III) complexes of diisopropylthiourea have been synthesized and characterized by elemental analyses, molar conductivity, magnetic susceptibility, FTIR and electronic spectroscopy. The compounds are non-electrolytes in solution and spectroscopic data of the complexes are consistent with 4-coordinate geometry for the metal(II) complexes and six coordinate octahedral for Fe(III) complex. The complexes were screened for their antibacterial activities against six bacteria: Escherichia coli, Pseudomonas auriginosa, Klebsiella pneumoniae, Bacillus cereus, Staphylococcus aureus and Bacillus pumilus. The complexes showed varied antibacterial activities and their minimum inhibitory concentrations (MICs) were determined.

  2. Crystallization of macromolecular complexes: combinatorial complex crystallization

    NASA Astrophysics Data System (ADS)

    Stura, Enrico A.; Graille, Marc; Charbonnier, Jean-Baptiste

    2001-11-01

    The usefulness of antibody complexation, as a way of increasing the chances of crystallization needs to be re-evaluated after many antibody complexes have been crystallized and their structure determined. It is somewhat striking that among these, only a small number is a complex with a large protein antigen. The problem is that the effort of raising, cleaving and purifying an Fab is rewarded only by an extra chance of getting crystals; depending on the relative likelihood of crystallization of the complexed and uncomplexed protein. The example of the complex between HIV gp120, CD4 and an Fab fragment from a neutralizing antibody suggests that further complexation of an antigen-antibody complex with a third protein could, by increasing the number of possible combinations, improve the likelihood of crystallization. We propose the use of Ig-binding proteins as a way of extending the method from HIV gp120 to all proteins for which there are monoclonal antibodies. We discuss this technique, combinatorial complex crystallization (CCC), as part of a multi-component system for the enhancement of crystallization of macromolecular complexes. The method makes use of single Ig-binding domains from Staphylococcus aureus protein A (SpA), Peptostreptococcus magnus protein L (PpL) and the streptococcal protein G (SpG). The generality of the method depends on the ability of these domains to interact with a large repertoire of antibodies without affecting antigen binding. There is strong evidence to suggest that these Ig-binding domains bind outside the antigen-combining site of the antibody without perturbing antigen binding. It is clear from the crystal structure of the single SpG domain complexed with an Fab that the interaction involves mainly the immunoglobulin CH1 domain, a region not involved in antigen recognition. We have recently determined the structure of the complex between a human Fab and the domain D from SpA and found that steric hindrance is unlikely even for large

  3. 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.

  4. 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

  5. Unusually high indoor radon concentrations

    NASA Astrophysics Data System (ADS)

    Ennemoser, O.; Ambach, W.; Brunner, P.; Schneider, P.; Oberaigner, W.; Purtscheller, F.; Stingl, V.

    Measurements of indoor radon concentrations in the village Umhausen (2600 inhabitants, Ötztal valley, Tyrol, Austria) revealed unusually high indoor radon concentrations up to 274,000 Bq m -3. The medians measured on the basements were 3750 Bq m -3 in winter and 361 Bq m -3 in summer, those on the ground floors were 1180 Bq m -3 and 210 Bq m -3, respectively. Seventy-one per cent of the houses showed basement radon concentrations above the Austrian action level of 400 Bq m -3 in winter, 33% in summer. There are indications that the high radon concentrations are due to a giant rock slide about 8700 years ago. The unusually high radon concentrations in Umhausen coincide with a statistically significant increase in lung cancer mortality. For the period 1970-1991 the age and sex standardized mortality rate is 3.85 (95% confidence interval: 2.9 to 5.1). The control population is the total population of Tyrol (630,000 inhabitants).

  6. Complex Correspondence Principle

    SciTech Connect

    Bender, Carl M.; Meisinger, Peter N.; Hook, Daniel W.; Wang Qinghai

    2010-02-12

    Quantum mechanics and classical mechanics are distinctly different theories, but the correspondence principle states that quantum particles behave classically in the limit of high quantum number. In recent years much research has been done on extending both quantum and classical mechanics into the complex domain. These complex extensions continue to exhibit a correspondence, and this correspondence becomes more pronounced in the complex domain. The association between complex quantum mechanics and complex classical mechanics is subtle and demonstrating this relationship requires the use of asymptotics beyond all orders.

  7. Miniaturized Cassegrainian concentrator concept demonstration

    NASA Astrophysics Data System (ADS)

    Patterson, R. E.; Rauschenbach, H. S.

    High concentration ratio photovoltaic systems for space applications have generally been considered impractical because of perceived difficulties in controlling solar cell temperatures to reasonably low values. A miniaturized concentrator system is now under development which surmounts this objection by providing acceptable solar cell temperatures using purely passive cell cooling methods. An array of identical miniaturized, rigid Cassegrainian optical systems having a low f-number with resulting short dimensions along their optical axes are rigidly mounted into a frame to form a relatively thin concentrator solar array panel. A number of such panels, approximately 1.5 centimeters thick, are wired as an array and are folded against one another for launch in a stowed configuration. Deployment on orbit is similar to the deployment of conventional planar honeycomb panel arrays or flexible blanket arrays. The miniaturized concept was conceived and studied in the 1978-80 time frame. Progress in the feasibility demonstration to date is reported.

  8. 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.

  9. Analysis of preferential particle concentration

    NASA Astrophysics Data System (ADS)

    Shariff, Karim

    2008-11-01

    It is known from simulations of particle laden turbulent flows (Squires and Eaton 1991; Wang and Maxey 1993) that particles having a relaxation time nearly equal to the Kolmogorov time preferentially concentrate in regions of weak vorticity. Here we consider the set of equations for particle dilatation, strain, and rotation which provides an understanding of this behavior. This set is derived from the two-fluid equations for the coupled fluid and particle phases. Fluid strain induces particle strain, which causes particle dilatation to always decrease. Fluid rotation, on the other hand, induces particle rotation, which causes particle dilatation to always increase. Illustrative solutions are provided for spatially linear flows and the case of pure strain nicely illustrates how particles concentrate. The analysis also suggests devices and flows that would be particularly good at concentrating particles.

  10. 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

  11. Energy 101: Concentrating Solar Power

    ScienceCinema

    None

    2016-07-12

    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.

  12. 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.

  13. Complex virial theorem and complex scaling

    SciTech Connect

    Junker, B.R.

    1983-06-01

    We present the simple generalization to complex energies of the normal global real scaling used for bound-state calculations to produce a variational energy which satisfies the virial theorem. We show that in two limiting cases, one or the other of which is almost always p satisfied in all calculations, the virially stabilized complex energy is sensitive to only the real part or the imaginary part of the complex virial expression. We then compute the virial expression for a number of wave functions for the 1s2s/sup 2/ /sup 2/S He/sup -/, 1s2s2p /sup 2/P/sup o/ He/sup -/, and 1s/sup 2/2s/sup 2/kp /sup 2/P/sup o/ Be/sup -/ resonances and the corresponding virially stabilized resonance energies. In all calculations one of the limiting cases was applicable.

  14. 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.

  15. 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.

  16. Compact Concentrators for Solar Cells

    NASA Technical Reports Server (NTRS)

    Whang, V. S.

    1984-01-01

    Each cell in array has own concentrator. A Cassegrain Reflector combination of paraboloidal and hyperboloidar mirrors-used with conical reflector at each element of array. Three components direct light to small solar cell. No cooling fins, fans, pumps, or heat pipes needed, not even in vacuum.

  17. 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.

  18. 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.

  19. Spectrophotometric determination of protein concentration.

    PubMed

    Simonian, Michael H

    2004-09-01

    This unit describes spectrophotometric and colorimetric methods for measuring the concentration of a sample protein in solution. Absorbance measured at 280 nm (A(280)) is used to calculate protein concentration by comparison with a standard curve or published absorptivity values for that protein (a(280)). Alternatively, absorbance measured at 205 nm (A(205)) is used to calculate the protein concentration. The A(280) and A(205) methods can be used to quantify total protein in crude lysates and purified or partially purified protein. A spectrofluorometer or a filter fluorometer can be used to measure the intrinsic fluorescence emission of a sample solution; this value is compared with the emissions from standard solutions to determine the sample concentration. The fluorescence emission method is used to quantify purified protein. This simple method is useful for dilute protein samples and can be completed in a short amount of time. There are two colorimetric methods: the Bradford colorimetric method, based upon binding of the dye Coomassie brilliant blue to the protein of interest, and the Lowry method, which measures colorimetric reaction of tyrosyl residues in the protein sample.

  20. 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...

  1. Segmented holographic spectrum splitting concentrator

    NASA Astrophysics Data System (ADS)

    Ayala, Silvana P.; Vorndran, Shelby; Wu, Yuechen; Chrysler, Benjamin; Kostuk, Raymond K.

    2016-09-01

    This paper presents a segmented parabolic concentrator employing holographic spectral filters that provide focusing and spectral bandwidth separation capability to the system. Strips of low band gap silicon photovoltaic (PV) cells are formed into a parabolic surface as shown by Holman et. al. [1]. The surface of the PV segments is covered with holographic elements formed in dichromated gelatin. The holographic elements are designed to transmit longer wavelengths to silicon cells, and to reflect short wavelength light towards a secondary collector where high-bandgap PV cells are mounted. The system can be optimized for different combinations of diffuse and direct solar illumination conditions for particular geographical locations by controlling the concentration ratio and filtering properties of the holographic elements. In addition, the reflectivity of the back contact of the silicon cells is used to increase the optical path length and light trapping. This potentially allows the use of thin film silicon for the low bandgap PV cell material. The optical design combines the focusing properties of the parabolic concentrator and the holographic element to control the concentration ratio and uniformity of the spectral distribution at the high bandgap cell location. The presentation concludes with a comparison of different spectrum splitting holographic filter materials for this application.

  2. Viscoelasticity of Concentrated Proteoglycan Solutions

    NASA Astrophysics Data System (ADS)

    Meechai, Nispa; Jamieson, Alex; Blackwell, John; Carrino, David

    2001-03-01

    Proteoglycan Aggregate (PGA) is the principal macromolecular component of the energy-absorbing matrix of cartilage and tendon. Its brush-like supramolecular structure consists of highly-ionic subunits, non-covalently bound to a hyaluronate chain. We report viscoelastic behavior of concentrated solutions of PGA, purified by column fractionation to remove free subunits. At physiological ionic strength, these preparations exhibit a sol-to-gel transition when the concentration is increased above molecular overlap. The strain dependence of concentrated solutions shows a pronounced non-linearity above a critical strain, at which the storage modulus decreases suddenly, and the loss modulus exhibits a maximum. This response is similar to that observed for close-packed dispersions of soft spheres, when the applied strain is sufficient to move a sphere past its neighbors. At low and high ionic strength, the elasticity of solutions near the overlap concentration decreases. The former is interpreted as due to a decrease in intramolecular and intermolecular electrostatic repulsions, because of strong trapping of counterions within the PGA brush, the latter to salt-induced brush collapse.

  3. Concentrated Placement of Student Teachers.

    ERIC Educational Resources Information Center

    Augenstein, Mildred B.; Tennis, Melvin H., Jr.

    During the 1968-69 school year the Dade County, Florida, Public Schools conducted an experiment in which student teachers were placed in concentrated numbers among selected schools. The program involved 15 elementary and secondary schools as experimental student-teaching centers into which 212 student teachers were placed from the University of…

  4. Amylose-iodine complex. I. Sedimentation behavior.

    PubMed

    Dintzis, F R; Beckwith, A C; Babcock, G E; Tobin, R

    1976-01-01

    Sedimentation measurements are reported on solutions of blue amylose-iodine complexes in the range of 0.001 to 0.007% amylose. Amylose fractions B and F2, of weight average molecular weight average molecular weight 4.0 X 10(5) and 3.4 X 10(4), respectively, were used in this study. Iodine complexes of these fractions formed polydisperse solutions of limited solubility and stability. Sedimentation coefficients increased as a function of potassium iodide concentration. Values for fraction B complexes varied from (16.3 +/- 1.0) X 10(-13) at 1.2 X 10(-3) M KI to (57.2 +/- 7.5) X 10(-13) at 8.3 X 10(-3) M KI; values for fraction F2 complexes varied from (10.0 +/- 1.2) X 10(-13) at 1.2 X 10(-13) M KI to (24.8 +/- 3.9) X 10(-13) at 9.5 X 10(-3) M KI. At constant potassium iodide concentration, sedimentation coefficients, within our experimental error of 10 to 15% standard deviation, are independent of amylose concentration. Time dependence of sedimentation coefficient values was observed for solutions either saturated or unsaturated with respect to the iodine-binding capacity of amylose. For iodine-saturated complex solutions, sedimentation coefficients extrapolated to zero potassium iodide concentration were two to three times greater than for the parent amylose. Measurements are evaluated in terms of possible polyelectrolytic charge effects and aggregation. Under conditions used in these experiments, aggregation of amylose-iodide complexes appears to be the mechanism responsible for the large increase in sedimentation coefficients.

  5. Phonological processing is uniquely associated with neuro-metabolic concentration.

    PubMed

    Bruno, Jennifer Lynn; Lu, Zhong-Lin; Manis, Franklin R

    2013-02-15

    Reading is a complex process involving recruitment and coordination of a distributed network of brain regions. The present study sought to establish a methodologically sound evidentiary base relating specific reading and phonological skills to neuro-metabolic concentration. Single voxel proton magnetic resonance spectroscopy was performed to measure metabolite concentration in a left hemisphere region around the angular gyrus for 31 young adults with a range of reading and phonological abilities. Correlation data demonstrated a significant negative association between phonological decoding and normalized choline concentration and as well as a trend toward a significant negative association between sight word reading and normalized choline concentration, indicating that lower scores on these measures are associated with higher concentrations of choline. Regression analyses indicated that choline concentration accounted for a unique proportion of variance in the phonological decoding measure after accounting for age, cognitive ability and sight word reading skill. This pattern of results suggests some specificity for the negative relationship between choline concentration and phonological decoding. To our knowledge, this is the first study to provide evidence that choline concentration in the angular region may be related to phonological skills independently of other reading skills, general cognitive ability, and age. These results may have important implications for the study and treatment of reading disability, a disorder which has been related to deficits in phonological decoding and abnormalities in the angular gyrus.

  6. Terahertz carrier dynamics and dielectric properties of GaN epilayers with different carrier concentrations

    NASA Astrophysics Data System (ADS)

    Guo, H. C.; Zhang, X. H.; Liu, W.; Yong, A. M.; Tang, S. H.

    2009-09-01

    Using terahertz time-domain spectroscopy, we measured the complex conductivity and dielectric function of n-type GaN with various carrier concentrations on sapphire substrate. The measured complex conductivity, which is due to the free carriers, is well fitted by simple Drude model. The contribution from the lattice vibration to the complex dielectric function increases with the decrease in free carrier concentration. A better fitting of the frequency-dependent complex dielectric response was obtained by considering both of the Drude and the classical damped oscillator model.

  7. 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.

    2016-05-01

    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.

  8. 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.

  9. Visual complexity: a review.

    PubMed

    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 research on single forms, form and texture arrays and visual displays. Form complexity and form probability are shown to be linked through their reciprocal relationship in complexity theory, which is in turn shown to be consistent with recent developments in perceptual learning and neural circuit theory. Directions for further research are suggested.

  10. Optical Properties of Concentrated Dispersions.

    NASA Astrophysics Data System (ADS)

    Molloy, Peter J.

    Available from UMI in association with The British Library. Apparatus and methods have been developed to measure the diffuse transmittance T and reflectance R of multiple scattering, concentrated, colloidal dispersions. The variation of R and T with pathlength, wavelength, and concentration has been investigated for non-spherical particles in concentrated dispersions, over a range of pH and surfactant concentrations. Measurements of diffuse transmittance and reflectance required large corrections to be made for the presence of any specular interfaces i.e. windows. These corrections were minimised by developing a bifurcated fibre optic bundle reflectance method, which allowed R and T to be measured at volume fractions up to at least 0.3. Using magnetic, acoustic and shear fields to align the non-spherical kaolinite particles changes in R and T were measured at volume fractions upto 0.3. The amplitude of the changes and the relaxation of the changes induced by the applied fields were measured. The amplitude of the change was found to vary strongly with pH and surfactant concentration. For any particular face diameter platelet, the amplitude of the change followed closely the flocculation process, and was sensitive to the mode of particle-particle aggregation, e.g. face-face, or face-edge. The amount of surfactant per unit mass of kaolinite required to stabilise dispersions is found to vary with particle size and concentration. This showed that information about particle orientation can be obtained through multiple scattering systems when subjected to an aligning field. Kubelka-Munk two flux theory was used to relate R and T to the diffuse flux scattering parameter S. A simple theory was developed relating S to the size shape and orientation of the non-spherical particles, hence allowing the particle orientation to be determined for any aligning field. The insight into particle behaviour given by the optical method is superior to that given by rheology alone, which

  11. A Comparison Of Tracking Methods For Solar Concentrators

    NASA Astrophysics Data System (ADS)

    Eckhardt, Stephen K.

    1984-01-01

    The method of tracking used by a solar concentrator has an effect both on the cost of the system and on the size of concentrator necessary to collect a given amount of energy. A simple computer model was used to compare a mirror utilization factor, defined as the energy collected per unit mirror area, for five types of collectors: a fully tracking paraboloid, a North-South tracking parabolic trough, the General Atomics-Russell collector, a fixed spherical bowl with a tracking receiver, and a fixed mirror collector such as a CPC or a cusp. Two cases were considered: sea horizon and low-sun-angle shading. As might be expected, the mirror utilization factor for a given concentrator was found to be roughly proportional to the complexity of the tracking system, and therefore its cost, however, there are some seasonal variations which might make one type of concentrator more desirable than another in a given situation.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Nanocrystals for luminescent solar concentrators.

    PubMed

    Bradshaw, Liam R; Knowles, Kathryn E; McDowall, Stephen; Gamelin, Daniel R

    2015-02-11

    Luminescent solar concentrators (LSCs) harvest sunlight over large areas and concentrate this energy onto photovoltaics or for other uses by transporting photons through macroscopic waveguides. Although attractive for lowering solar energy costs, LSCs remain severely limited by luminophore reabsorption losses. Here, we report a quantitative comparison of four types of nanocrystal (NC) phosphors recently proposed to minimize reabsorption in large-scale LSCs: two nanocrystal heterostructures and two doped nanocrystals. Experimental and numerical analyses both show that even the small core absorption of the leading NC heterostructures causes major reabsorption losses at relatively short transport lengths. Doped NCs outperform the heterostructures substantially in this critical property. A new LSC phosphor is introduced, nanocrystalline Cd(1-x)Cu(x)Se, that outperforms all other leading NCs by a significant margin in both small- and large-scale LSCs under full-spectrum conditions.

  17. 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.

  18. Arsenic concentrations in Chinese coals.

    PubMed

    Wang, Mingshi; Zheng, Baoshan; Wang, Binbin; Li, Shehong; Wu, Daishe; Hu, Jun

    2006-03-15

    The arsenic concentrations in 297 coal samples were collected from the main coal-mines of 26 provinces in China were determined by molybdenum blue coloration method. These samples were collected from coals that vary widely in coal rank and coal-forming periods from the five main coal-bearing regions in China. Arsenic content in Chinese coals range between 0.24 to 71 mg/kg. The mean of the concentration of Arsenic is 6.4+/-0.5 mg/kg and the geometric mean is 4.0+/-8.5 mg/kg. The level of arsenic in China is higher in northeastern and southern provinces, but lower in northwestern provinces. The relationship between arsenic content and coal-forming period, coal rank is studied. It was observed that the arsenic contents decreases with coal rank in the order: Tertiary>Early Jurassic>Late Triassic>Late Jurassic>Middle Jurassic>Late Permian>Early Carboniferous>Middle Carboniferous>Late Carboniferous>Early Permian; It was also noted that the arsenic contents decrease in the order: Subbituminous>Anthracite>Bituminous. However, compared with the geological characteristics of coal forming region, coal rank and coal-forming period have little effect on the concentration of arsenic in Chinese coal. The average arsenic concentration of Chinese coal is lower than that of the whole world. The health problems in China derived from in coal (arsenism) are due largely to poor local life-style practices in cooking and home heating with coal rather than to high arsenic contents in the coal.

  19. Tactical Responses to Concentrated Artillery

    DTIC Science & Technology

    1989-01-01

    aerial artillery at General Heinz Guderian’s crossing of the Meuse in May 1940 is indicative of the operational effect of tactical concentration at the...of maneuver they wished to fight. Another former tsarist artilleryman, General Golovin , argued in a 1925 article that artillery was even more...important in maneuver warfare. According to Golovin , it is necessary in order to preserve one’s freedom to maneuver and to deny it to the enemy: "The initial

  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.

  1. Freeze concentration beats the heat

    SciTech Connect

    Rosen, J.

    1990-12-01

    This paper reports on freeze concentration (FC) which saves energy and money in packaging, shipping, and storing food products. FC---in contrast to existing heat-evaporation processes---retains volatile flavor and aroma compounds in food products so that no additives are required to restore the taste and smell of the original product. In recent tests on orange, grapefruit, and pineapple juices, reconstituted FC juices were found to be superior in taste to juices produced by evaporation and similar to the original pasteurized juices. The dairy industry, which is the largest user of energy for concentration in the food sector, is looking to FC for new products such as frozen concentrated milk as well as better use of the milk by-products of cheese production. The biggest potential for new FC applications is in those industries that consume large amounts of energy for separation processing, according to a 1987 report prepared for EPRI. In the food industry, this includes milk, vinegar, and beer producers. Potential applications also abound in the pulp and paper, pharmaceutical, chemical, and petroleum industries. FC separates substances via crystallization at substantial energy savings.

  2. Photovoltaic concentrator module improvements study

    SciTech Connect

    Levy, S.L.; Kerschen, K.A. ); Hutchison, G. ); Nowlan, M.J. )

    1991-08-01

    This report presents results of a project to design and fabricate an improved photovoltaic concentrator module. Using previous work as a baseline, this study conducted analyses and testing to select major module components and design features. The lens parquet and concentrator solar cell were selected from the highest performing, available components. A single 185X point-focus module was fabricated by the project team and tested at Sandia. Major module characteristics include a 6 by 4 compression-molded acrylic lens parquet (0.737 m{sup 2} area), twenty-four 0.2 ohms-cm, FZ, p-Si solar cells (1.56 cm{sup 2} area) soldered to ceramic substrates and copper heat spreaders, and an aluminized steel housing with corrugated bottom. This project marked the first attempt to use prismatic covers on solar cells in a high-concentration, point-focus application. Cells with 15 percent metallization were obtained, but problems with the fabrication and placement of prismatic covers on these cells lead to the decision not to use covers in the prototype module. Cell assembly fabrication, module fabrication, and module optical design activities are presented here. Test results are also presented for bare cells, cell assemblies, and module. At operating conditions of 981 watts/m{sup 2} DNI and an estimated cell temperature of 65{degrees}C, the module demonstrated an efficiency of 13.9 percent prior to stressed environmental exposure. 12 refs., 56 figs., 7 tabs.

  3. Advanced high efficiency concentrator cells

    SciTech Connect

    Gale, R. . Varian Research Center)

    1992-06-01

    This report describes research to develop the technology needed to demonstrate a monolithic, multijunction, two-terminal, concentrator solar cell with a terrestrial power conversion efficiency greater than 35%. Under three previous subcontracts, Varian developed many of the aspects of a technology needed to fabricate very high efficiency concentrator cells. The current project was aimed at exploiting the new understanding of high efficiency solar cells. Key results covered in this report are as follows. (1) A 1.93-eV AlGaAs/1.42-eV GaAs metal-interconnected cascade cell was manufactured with a one-sun efficiency at 27.6% at air mass 1.5 (AM1.5) global. (2) A 1.0eV InGaAs cell was fabricated on the reverse'' side of a low-doped GaAs substrate with a one-sun efficiency of 2.5% AM1.5 diffuse and a short-circuit current of 14.4 mA/cm{sup 2}. (3) Small-scale manufacturing of GaAs p/n concentrator cells was attempted and obtained an excellent yield of high-efficiency cells. (4) Grown-in tunnel junction cell interconnects that are transparent and thermally stable using C and Si dopants were developed. 10 refs.

  4. Sample concentration using optical chromatography

    NASA Astrophysics Data System (ADS)

    Hart, Sean J.; Terray, Alex; Arnold, Jonathan; Leski, Tomasz A.

    2007-03-01

    Optical chromatography is a technique for the separation of particles that capitalizes on the balance between optic and fluidic forces. When microscopic particles in a fluid flow encounter a laser beam propagating in the opposite direction, they are trapped axially along the beam. They are then optically pushed upstream from the laser focal point to rest at a point where the optic and fluidic forces on the particle balance. Because optical and fluid forces are sensitive to differences in the physical and chemical properties of a particle, both coarse and fine separations are possible. We describe how an optical chromatography beam directed into a tailored flow environment, has been adapted to operate as an optical filter for the concentration / bioenrichment of colloidal and biological samples. In this work, the demonstrated ability to concentrate spores of the biowarfare agent, Bacillus anthracis, may have significant impact in the biodefense arena. Application of these techniques and further design of fluidic and optical environments will allow for more specific identification, concentration and separation of many more microscopic particle and biological suspensions.

  5. Purification and concentration of alphavirus.

    PubMed

    Lundstrom, Kenneth

    2012-07-01

    The alphaviruses Semliki Forest virus and Sindbis virus have been used frequently as expression vectors in vitro and in vivo. Usually, these systems consist of replication-deficient vectors that require a helper vector for packaging of recombinant particles. Replication-proficient vectors have also been engineered. Alphaviral vectors can be used as nucleic-acid-based vectors (DNA and RNA) or infectious particles. High-titer viral production is achieved in <2 d. The broad host range of alphaviruses facilitates studies in mammalian and nonmammalian cell lines, primary cells in culture, and in vivo. The strong preference for expression in neuronal cells has made alphaviruses particularly useful in neurobiological studies. Unfortunately, their strong cytotoxic effect on host cells, relatively short-term transient expression patterns, and the reasonably high cost of viral production remain drawbacks. However, novel mutant alphaviruses have showed reduced cytotoxicity and prolonged expression. Membrane proteins (which are generally difficult to express at high levels in recombinant systems) have generated high yields and facilitate applications in structural biology. Alphaviruses have also been applied in vaccine development and gene therapy. Generally, purification or concentration of alphaviruses is not necessary. However, for instance, the medium derived from baby hamster kidney cells is toxic to primary neurons in culture. Including a purification step substantially improves the survival of the transduced neurons. Viral concentration and purification may also be advantageous for in vivo studies in animal models and are mandatory for clinical applications. This protocol describes three methods for purification and concentration of alphavirus.

  6. 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.

  7. Adulthood Obesity Is Positively Associated with Adipose Tissue Concentrations of Vitamin K and Inversely Associated with Circulating Indicators of Vitamin K Status in Men and Women1–3

    PubMed Central

    Shea, M. Kyla; Booth, Sarah L.; Gundberg, Caren M.; Peterson, James W.; Waddell, Catherine; Dawson-Hughes, Bess; Saltzman, Edward

    2010-01-01

    Increased adiposity is associated with increased storage of several fat-soluble nutrients. However, the extent to which vitamin K is stored in fat and the association between vitamin K status and adiposity are unknown. Our objectives in this study were to determine whether vitamin K is stored in human adipose tissue and the association between vitamin K status and body fat in older men and women. In study A, the vitamin K concentration of subcutaneous and visceral adipose tissue was quantified in samples taken from 16 gastric bypass patients [13 women, 3 men, age 40 ± 10 y (mean ± SD)] using HPLC. In study B, cross-sectional associations between percent body fat (%BF) and circulating measures of vitamin K status were examined in 260 women and 183 men [age = 68 ± 5 y]. The phylloquinone (K1) concentrations in subcutaneous and visceral adipose tissue were 148.2 ± 71.8 and 175 ± 112 nmol/kg, respectively, which is higher than the reported concentrations of other organs known to store vitamin K. There was an inverse association between %BF and plasma K1 in women (P-trend < 0.001). Higher %BF was associated with greater circulating concentrations of uncarboxylated prothrombin, indicative of lower hepatic utilization of vitamin K in both men (P-trend = 0.02) and women (P-trend = 0.002) but not with the percentage of undercarboxylated osteocalcin. Adipose tissue contained high concentrations of vitamin K, and increased adiposity was associated with poorer vitamin K status in older adults. Additional studies are needed to further explore the relationships among body fat, storage of vitamin K in adipose tissue, and implications for vitamin K status and function. PMID:20237066

  8. Adaptive Leadership: Fighting Complexity with Complexity

    DTIC Science & Technology

    2014-06-01

    It appears that, as Jorge Luis Borges put it, “Everything touches everything.”39 Army ants and the World Wide Web are exemplars of complex systems...Star Trek: USS Enterprise: Haynes Manual (San Jose , CA: Simon and Schuster, 2010). 66 Spillane, Distributed Leadership. 24... Jose , CA: Simon and Schuster, 2010. Smythe, Elizabeth, and Andrew Norton. “Thinking as Leadership/Leadership As Thinking.” Leadership 3, no. 1 (2007

  9. 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.

  10. U1A Complex

    ScienceCinema

    None

    2016-07-12

    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. 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

  12. 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…

  13. 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

  14. 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...

  15. Complexity and emergent phenomena.

    PubMed

    Suki, Béla; Bates, Jason H T; Frey, Urs

    2011-04-01

    Complex biological systems operate under non-equilibrium conditions and exhibit emergent properties associated with correlated spatial and temporal structures. These properties may be individually unpredictable, but tend to be governed by power-law probability distributions and/or correlation. This article reviews the concepts that are invoked in the treatment of complex systems through a wide range of respiratory-related examples. Following a brief historical overview, some of the tools to characterize structural variabilities and temporal fluctuations associated with complex systems are introduced. By invoking the concept of percolation, the notion of multiscale behavior and related modeling issues are discussed. Spatial complexity is then examined in the airway and parenchymal structures with implications for gas exchange followed by a short glimpse of complexity at the cellular and subcellular network levels. Variability and complexity in the time domain are then reviewed in relation to temporal fluctuations in airway function. Next, an attempt is given to link spatial and temporal complexities through examples of airway opening and lung tissue viscoelasticity. Specific examples of possible and more direct clinical implications are also offered through examples of optimal future treatment of fibrosis, exacerbation risk prediction in asthma, and a novel method in mechanical ventilation. Finally, the potential role of the science of complexity in the future of physiology, biology, and medicine is discussed.

  16. 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…

  17. 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…

  18. Complexity and behavioral economics.

    PubMed

    Rosser, J Barkley; Rosser, Marina V

    2015-04-01

    This paper will consider the relationship between complexity economics and behavioral economics. A crucial key to this is to understand that Herbert Simon was both the founder of explicitly modern behavioral economics as well as one of the early developers of complexity theory. Bounded rationality was essentially derived from Simon's view of the impossibility of full rationality on the part of economic agents. Modern complexity theory through such approaches as agent-based modeling offers an approach to understanding behavioral economics by allowing for specific behavioral responses to be assigned to agents who interact within this context, even without full rationality. Other parts of modern complexity theory are considered in terms of their relationships with behavioral economics. Fundamentally, complexity provides an ultimate foundation for bounded rationality and hence the need to use behavioral economics in a broader array of contexts than most economists have thought appropriate.

  19. Complexity: against systems.

    PubMed

    Chu, Dominique

    2011-09-01

    This article assumes a specific intuitive notion of complexity as a difficulty to generate and/or assess the plausibility of models. Based on this intuitive understanding of complexity, it identifies two main causes of complexity, namely, radical openness and contextuality. The former is the idea that there are no natural systems. The modeler always needs to draw artificial boundaries around phenomena to generate feasible models. Contextuality is intimately connected to the requirement to simplify models and to leave out most aspects. Complexity occurs when contextuality and radical openness cannot be contained that is when it is not clear where the boundaries of the system are and which abstractions are the correct ones. This concept of complexity is illustrated using a number of example from evolution.

  20. Window-Integrated Low Concentration Planar Light Guide Solar Concentrators

    NASA Astrophysics Data System (ADS)

    Williams, Daniel James Lawler

    Several novel low concentration solar concentrator photovoltaic designs are presented, based on the planar light guide architecture pioneered by the University of Rochester. These systems are designed for integration into windows, requiring them to be stationary and to have a large acceptance angle since they cannot move to track the sun. The application goal is to use solar generated electricity to offset the energy lost through the window during cold times of the year. The systems are evaluated for their effective insulation properties given the calculated net energy lost. Without moving parts, they optimize to have acceptance angles of about 20° to 35° in the vertical direction and +/-90° in the horizontal direction, but have peak optical efficiencies of less than 50%. By including internally moving parts, the acceptance angle is increased to nearly a full pi steradians (the full sky from the point of view of the window) and the average optical efficiency increases to over 50%. Systems in certain locations are not viable due to low solar irradiance in the wintertime, e.g., Rochester, NY. Others, however, reduce net energy loss to zero for much of the year. A prototype of one of the systems is fabricated, measured, and modeled. The simulated and measured performance data are compared and are in close agreement, validating the model and the evaluation methods used during system optimization.

  1. Structuring Light by Concentric-Ring Patterned Magnetic Metamaterial Cavities.

    PubMed

    Zeng, Jinwei; Gao, Jie; Luk, Ting S; Litchinitser, Natalia M; Yang, Xiaodong

    2015-08-12

    Ultracompact and tunable beam converters pose a significant potential for modern optical technologies ranging from classical and quantum communication to optical manipulation. Here we design and demonstrate concentric-ring patterned structures of magnetic metamaterial cavities capable of tailoring both polarization and phase of light by converting circularly polarized light into a vector beam with an orbital angular momentum. We experimentally illustrate the realization of both radially and azimuthally polarized vortex beams using such concentric-ring patterned magnetic metamaterials. These results contribute to the advanced complex light manipulation with optical metamaterials, making it one step closer to realizing the simultaneous control of polarization and orbital angular momentum of light on a chip.

  2. Effects of iron therapy on blood lead concentrations in infants.

    PubMed

    Park, Sangkyu; Sim, Chang Sun; Lee, Heun; Kim, Yangho

    2014-01-01

    To determine whether blood lead concentration is elevated in iron-deficient infants, blood lead and serum ferritin concentrations, serum iron/transferring iron-binding capacity (Fe/TIBC) and complete blood counts were measured in 30 iron deficient and 35 control infants, aged 6-24 months. All 30 iron-deficient infants received iron supplementation (ferric hydroxide-polymaltose complex, 6mg/kg Fe(3+)/day) for 1-6 months. Blood lead concentrations were measured in 18 of the iron deficient infants after their ferritin levels returned to the normal range. The geometric mean blood lead concentration was higher in iron deficient than in control infants (1.846 vs. 1.416μg/dL). After iron therapy, the blood lead levels of iron-deficient infants decreased significantly compared with pre-treatment levels (1.785 vs. 2.386μg/dL), and the hemoglobin and ferritin concentrations increased significantly. These findings indicate that iron deficiency increases blood lead concentrations in infants with very low blood lead concentrations.

  3. Antidotes for novel oral anticoagulants: current status and future potential.

    PubMed

    Crowther, Mark; Crowther, Mark A

    2015-08-01

    The direct thrombin inhibitor dabigatran and the anti-Xa agents rivaroxaban, edoxaban, and apixaban are a new generation of oral anticoagulants. Their advantage over the vitamin K antagonists is the lack of the need for monitoring and dose adjustment. Their main disadvantage is currently the absence of a specific reversal agent. Dabigatran's, unlike the anti-Xa agents, absorption can be reduced by activated charcoal if administered shortly after ingestion and it can be removed from the blood with hemodialysis. Prothrombin complex concentrate, activated prothrombin complex concentrate, and recombinant factor VIIa all show some activity in reversing the anticoagulant effect of these drugs but this is based on ex vivo, animal, and volunteer studies. It is unclear, which, if any, of these drugs is the most suitable for emergency reversal. Three novel molecules (idarucizumab, andexanet, and PER977) may provide the most effective and safest way of reversal. These agents are currently in premarketing studies.

  4. Understanding Equilibrium: The Study of Complex Systems. Final Project Report.

    ERIC Educational Resources Information Center

    Duckworth, Eleanor; And Others

    The Educational Technology Center (ETC) Complex Systems Project was initiated to explore ways of using computers to help students understand systems which have often proven too complex for most high school students to understand. Preliminary work concentrated on the cognitive processes involved in modeling simple systems. This paper describes an…

  5. Predicting indoor radon-222 concentration

    SciTech Connect

    Stowe, M.H.

    1994-12-31

    Radon, a cause of lung cancer among miners, is being investigated as a source of lung cancer in the general population due to long-term low-level exposures in residences. Assessment of cumulative residential radon exposure entails measurements in past residences, some of which no longer exist or are not accessible. Estimates of radon concentrations in these missing homes are necessary for analysis of the radon-lung cancer association. Various approaches have been used by researchers attempting to predict the distribution of radon measurements in homes from specified geological and building characteristics. This study has modelled the set of basement radon measurements of 3788 Connecticut homes with several of these approaches, in addition to a descriptive tree method not previously utilized, and compared their validity on a random subset of homes not used in model construction. Each geographical and geological variable was more predictive of radon concentration than any of the housing characteristics. The single variable which explained the largest fraction of the variability in radon readings was the mean radon concentration for the zipcode area in which the house was located (R{sup 2} = .157). Soil characteristics at individual housing sites were not available for these analyses. They would be expected to increase the predictive power of the models. Multiple regression models, both additive and multiplicative, were not able to explain more than 22% of the variation in radon readings. Variables found to be significant in these models were zipcode mean, residential radon mean of bedrock unit, building age, type of foundation walls, type of water supply, aeroradioactivity reading, and lithology of the bedrock. A site potential index, based upon a classification of the bedrock underlying the house, was a better predictor of indoor radon level than other single geological variables, yet only explained 8% of the radon variability.

  6. Concentrator testing using projected images

    NASA Astrophysics Data System (ADS)

    Jefferies, Kent S.

    The projected image system can be used to evaluate concentrator optical properties by comparing images reflected onto the ceiling of the test facility to theoretical facet outlines. This system was tested by comparing ceiling images to facet outlines computed using facet characteristics measured by the digital-image-radiometer (DIR) optical measuring system. The agreement was good, confirming the accuracy of both optical systems. Six facets were mounted in the centers of the pie sectors of one hexagonal panel. Differences between the facets and facet nonsymmetries were observed in photographs of the ceiling images of the facets.

  7. Concentrator testing using projected images

    NASA Technical Reports Server (NTRS)

    Jefferies, Kent S.

    1991-01-01

    The projected image system can be used to evaluate concentrator optical properties by comparing images reflected onto the ceiling of the test facility to theoretical facet outlines. This system was tested by comparing ceiling images to facet outlines computed using facet characteristics measured by the digital image radiometer (DIR) optical measuring system. The agreement was good, confirming the accuracy of both optical systems. Six facets were mounted in the centers of the pie sectors of one hexagonal panel. Differences between the facets and facet nonsymmetries were observed in photographs of the ceiling images of these facets.

  8. Concentrator testing using projected images

    NASA Technical Reports Server (NTRS)

    Jefferies, Kent S.

    1991-01-01

    The projected image system can be used to evaluate concentrator optical properties by comparing images reflected onto the ceiling of the test facility to theoretical facet outlines. This system was tested by comparing ceiling images to facet outlines computed using facet characteristics measured by the digital-image-radiometer (DIR) optical measuring system. The agreement was good, confirming the accuracy of both optical systems. Six facets were mounted in the centers of the pie sectors of one hexagonal panel. Differences between the facets and facet nonsymmetries were observed in photographs of the ceiling images of the facets.

  9. Concentrating Solar Power Program overview

    SciTech Connect

    1998-04-01

    Over the last decade, the US solar thermal industry has established a track record in the power industry by building and operating utility-scale power plants with a combined rated capacity of 354 megawatts (MW). The technology used in these power plants is based on years of research and development (R and D), much of it sponsored by the US Department of Energy (DOE). DOE`s Concentrating Solar Power (CSP) Program is collaborating with its partners in the private sector to develop two new solar technologies -- power towers and dish/engines -- to meet the huge commercial potential for solar power.

  10. Solar concentrator advanced development project

    NASA Technical Reports Server (NTRS)

    Corrigan, Robert D.; Ehresman, Derik T.

    1987-01-01

    A solar dynamic concentrator design developed for use with a solar-thermodynamic power generation module intended for the Space Station is considered. The truss hexagonal panel reflector uses a modular design approach and is flexible in attainable flux profiles and assembly techniques. Preliminary structural, thermal, and optical analysis results are discussed. Accuracy of the surface reflectors should be within 5 mrad rms slope error, resulting in the need for close fabrication tolerances. Significant fabrication issues to be addressed include the facet reflective and protective coating processes and the surface specularity requirements.

  11. Thermochromic platinum complexes

    DOEpatents

    Kostic, Nenad M.; Zhou, Xia-Ying

    1990-05-29

    Thermochromic compounds containing the [Pt(dipic)Cl].sup.- anion. These compounds are yellow and monomeric at high temperatures or in low concentrations and abruptly change to red and polymeric at low temperatures or higher solution concentrations. This unusual property allows them to be used as temperature sensors.

  12. Thermochromic platinum complexes

    DOEpatents

    Kostic, Nenad M.; Zhou, Xia-Ying

    1989-08-15

    Thermochromic compounds containing the [Pt(dipic)Cl].sup.- anion. These compounds are yellow and monomeric at high temperatures or in low concentrations and abruptly change to red and polymeric at low temperatures or higher solution concentrations. This unusual property allows them to be used as temperature sensors.

  13. Selenophene transition metal complexes

    SciTech Connect

    White, Carter James

    1994-07-27

    This research shows that selenophene transition metal complexes have a chemistry that is similar to their thiophene analogs. Selenophene coordination has been demonstrated and confirmed by molecular structure in both the η5- and the η1(Se)-coordination modes. The reaction chemistry of selenophene complexes closely resembles that of the analogous thiophene complexes. One major difference, however, is that selenophene is a better donor ligand than thiophene making the selenophene complexes more stable than the corresponding thiophene complexes. The 77Se NMR chemical shift values for selenophene complexes fall within distinct regions primarily depending on the coordination mode of the selenophene ligand. In the final paper, the C-H bond activation of η1(S)-bound thiophenes, η1(S)-benzothiophene and η1(Se)-bound selenophenes has been demonstrated. The deprotonation and rearrangement of the η1(E)-bound ligand to the carbon bound L-yl complex readily occurs in the presence of base. Reprotonation with a strong acid gives a carbene complex that is unreactive towards nucleophilic attack at the carbene carbon and is stable towards exposure to air. The molecular structure of [Cp(NO)(PPh3)Re(2-benzothioenylcarbene)]O3SCF3 was determined and contains a Re-C bond with substantial double bond character. Methyl substitution for the thienylcarbene or selenylcarbene gives a carbene that rearranges thermally to give back the η1(E)-bound complex. Based on these model reactions, a new mechanism for the H/D exchange of thiophene over the hydrodesulfurization catalyst has been proposed.

  14. Saloplastics: processing compact polyelectrolyte complexes.

    PubMed

    Schaaf, Pierre; Schlenoff, Joseph B

    2015-04-17

    Polyelectrolyte complexes (PECs) are prepared by mixing solutions of oppositely charged polyelectrolytes. These diffuse, amorphous precipitates may be compacted into dense materials, CoPECs, by ultracentrifugation (ucPECs) or extrusion (exPECs). The presence of salt water is essential in plasticizing PECs to allow them to be reformed and fused. When hydrated, CoPECs are versatile, rugged, biocompatible, elastic materials with applications including bioinspired materials, supports for enzymes and (nano)composites. In this review, various methods for making CoPECs are described, as well as fundamental responses of CoPEC mechanical properties to salt concentration. Possible applications as synthetic cartilage, enzymatically active biocomposites, self-healing materials, and magnetic nanocomposites are presented.

  15. Afterglow Complex Plasma

    SciTech Connect

    Samarian, A. A.; Boufendi, L.; Mikikian, M.

    2008-09-07

    The review of the first detailed experimental and theoretical studies of complex plasma in RF discharge afterglow is presented. The studies have been done in a frame of FAST collaborative research project between Complex Plasma Laboratory of the University of Sydney and the GREMI laboratory of Universite d'Orleans. We examined the existing models of plasma decay, presents experimental observations of dust dynamics under different afterglow complex plasma conditions, presents the experimental data obtained (in particular the presence of positively charged particles in discharge afterglow), discusses the use of dust particles as a probe to study the diffusion losses in afterglow plasmas.

  16. Complexity and robustness

    PubMed Central

    Carlson, J. M.; Doyle, John

    2002-01-01

    Highly optimized tolerance (HOT) was recently introduced as a conceptual framework to study fundamental aspects of complexity. HOT is motivated primarily by systems from biology and engineering and emphasizes, (i) highly structured, nongeneric, self-dissimilar internal configurations, and (ii) robust yet fragile external behavior. HOT claims these are the most important features of complexity and not accidents of evolution or artifices of engineering design but are inevitably intertwined and mutually reinforcing. In the spirit of this collection, our paper contrasts HOT with alternative perspectives on complexity, drawing on real-world examples and also model systems, particularly those from self-organized criticality. PMID:11875207

  17. Complexity and forensic pathology.

    PubMed

    Jones, Richard Martin

    2015-12-01

    It has become increasingly apparent that nonlinearity and complexity are the norm in human physiological systems, the relevance of which is informing an enhanced understanding of basic pathological processes such as inflammation, the host response to severe trauma, and critical illness. This article will explore how an understanding of nonlinear systems and complexity might inform the study of the pathophysiology of deaths of medicolegal interest, and how 'complexity thinking' might usefully be incorporated into modern forensic medicine and forensic pathology research, education and practice.

  18. Sertraline concentrations and postmortem redistribution.

    PubMed

    McIntyre, Iain M; Mallett, Phyllis

    2012-11-30

    Sertraline is a commonly prescribed selective inhibitor of serotonin uptake used for the treatment of mental depression and anxiety. Central blood and liver concentrations of sertraline (norsertraline) are compared to levels in peripheral blood in nine medical examiner cases. Specimens were initially screened for alcohol and simple volatiles by GC-FID headspace analysis, ELISA for drugs of abuse, and alkaline drugs by GC/MS. Sertraline, when detected by the alkaline drug screen, was subsequently confirmed and quantified by a specific GC-NPD procedure. Data suggest that when ingested with other medications, sertraline may be a contributing factor in death. Sertraline (norsertraline) concentrations ranged from 0.13 (0.11) to 2.1 (6.0) mg/L in peripheral blood, from 0.18 (0.12) to 2.0 (6.7) mg/L in central blood, and 21 to 160 mg/kg in liver. Sertraline central blood to peripheral blood ratios averaged 1.22±0.85 (mean±standard deviation). The liver to peripheral blood ratios, on the other hand, were markedly higher and averaged 97±40 (mean±standard deviation). Given that a liver to peripheral blood ratio exceeding 20 is indicative of propensity for significant postmortem redistribution, these data confirm that sertraline is prone to marked postmortem redistribution.

  19. Nitrate concentrations under irrigated agriculture

    USGS Publications Warehouse

    Zaporozec, A.

    1983-01-01

    In recent years, considerable interest has been expressed in the nitrate content of water supplies. The most notable toxic effect of nitrate is infant methemoglobinemia. The risk of this disease increases significantly at nitrate-nitrogen levels exceeding 10 mg/l. For this reason, this concentration has been established as a limit for drinking water in many countries. In natural waters, nitrate is a minor ionic constituent and seldom accounts for more than a few percent of the total anions. However, nitrate in a significant concentration may occur in the vicinity of some point sources such as septic tanks, manure pits, and waste-disposal sites. Non-point sources contributing to groundwater pollution are numerous and a majority of them are related to agricultural activities. The largest single anthropogenic input of nitrate into the groundwater is fertilizer. Even though it has not been proven that nitrogen fertilizers are responsible for much of nitrate pollution, they are generally recognized as the main threat to groundwater quality, especially when inefficiently applied to irrigated fields on sandy soils. The biggest challenge facing today's agriculture is to maintain the balance between the enhancement of crop productivity and the risk of groundwater pollution. ?? 1982 Springer-Verlag New York Inc.

  20. Airborne concentrations of peanut protein.

    PubMed

    Johnson, Rodney M; Barnes, Charles S

    2013-01-01

    Food allergy to peanut is a significant health problem, and there are reported allergic reactions to peanuts despite not eating or having physical contact with peanuts. It is presumed that an allergic reaction may have occurred from inhalation of airborne peanut allergens. The purpose of this study was to detect the possible concentrations of airborne peanut proteins for various preparations and during specific activities. Separate Ara h 1 and Ara h 2 monoclonal enzyme-linked immunosorbent assays and a polyclonal sandwich enzyme immunoassay for peanuts were used to detect the amount of airborne peanut protein collected using a Spincon Omni 3000 air collector (Sceptor Industries, Inc., Kansas City, MO) under different peanut preparation methods and situations. Air samples were measured for multiple peanut preparations and scenarios. Detectable amounts of airborne peanut protein were measured using a whole peanut immunoassay when removing the shells of roasted peanut. No airborne peanut allergen (Ara h 1 or Ara h 2) or whole peanut protein above the LLD was measured in any of the other peanut preparation collections. Ara h 1, Ara h 2, and polyclonal peanut proteins were detected from water used to boil peanuts. Small amounts of airborne peanut protein were detected in the scenario of removing shells from roasted peanuts; however, Ara h 1 and Ara h 2 proteins were unable to be consistently detected. Although airborne peanut proteins were detected, the concentration of airborne peanut protein that is necessary to elicit a clinical allergic reaction is unknown.

  1. Chloramination of Concentrated Drinking Water for ...

    EPA Pesticide Factsheets

    Abstract for presentation on chloraminated drinking water concentrates to create whole DBP mixtures Abstract for presentation on chloraminating drinking water concentrates to create whole DBP mixtures

  2. A complex legacy

    NASA Astrophysics Data System (ADS)

    Moore, Cristopher

    2011-11-01

    In his tragically short life, Alan Turing helped define what computing machines are capable of, and where they reach inherent limits. His legacy is still felt every day, in areas ranging from computational complexity theory to cryptography and quantum computing.

  3. Indicators: Physical Habitat Complexity

    EPA Pesticide Factsheets

    Physical habitat complexity measures the amount and variety of all types of cove at the water’s edge in lakes. In general, dense and varied shoreline habitat is able to support more diverse communities of aquatic life.

  4. Complex Regional Pain Syndrome

    MedlinePlus

    Complex regional pain syndrome (CRPS) is a chronic pain condition. It causes intense pain, usually in the arms, hands, legs, or feet. ... in skin temperature, color, or texture Intense burning pain Extreme skin sensitivity Swelling and stiffness in affected ...

  5. Reconstruction Using Witness Complexes

    PubMed Central

    Oudot, Steve Y.

    2010-01-01

    We present a novel reconstruction algorithm that, given an input point set sampled from an object S, builds a one-parameter family of complexes that approximate S at different scales. At a high level, our method is very similar in spirit to Chew’s surface meshing algorithm, with one notable difference though: the restricted Delaunay triangulation is replaced by the witness complex, which makes our algorithm applicable in any metric space. To prove its correctness on curves and surfaces, we highlight the relationship between the witness complex and the restricted Delaunay triangulation in 2d and in 3d. Specifically, we prove that both complexes are equal in 2d and closely related in 3d, under some mild sampling assumptions. PMID:21643440

  6. Complex Flow Workshop Report

    SciTech Connect

    none,

    2012-05-01

    This report documents findings from a workshop on the impacts of complex wind flows in and out of wind turbine environments, the research needs, and the challenges of meteorological and engineering modeling at regional, wind plant, and wind turbine scales.

  7. Complex and unpredictable Cardano

    NASA Astrophysics Data System (ADS)

    Ekert, Artur

    2008-08-01

    This purely recreational paper is about one of the most colorful characters of the Italian Renaissance, Girolamo Cardano, and the discovery of two basic ingredients of quantum theory, probability and complex numbers.

  8. Concentric Nested Toroidal Inflatable Structures

    NASA Technical Reports Server (NTRS)

    Johnson, Christopher J.; Raboin, Jasen L.; Spexarth, Gary R.

    2010-01-01

    Assemblies comprising multiple limited- height toroidal inflatable structures nested in a concentric arrangement have been invented to obtain more design flexibility than can be obtained in single taller, wider toroidal inflatable structures (see figure). Originally intended for use as containers for habitats for humans in outer space or on remote planets, these and related prior inflatable structures could also be useful on Earth as lightweight, compactly stowable, portable special-purpose buildings that could be transported to remote locations and there inflated to full size and shape. In the case of a single inflatable toroidal structure, one important source of lack of design flexibility is the fact that an increase in outer diameter (which is sometimes desired) is necessarily accompanied by an increase in height (which is sometimes undesired). Increases in diameter and height can also cause difficulty in utilization of the resulting larger volume, in that it can become necessary to partition the volume by means of walls and floors, and features (e.g., stairs or ladders) must be added to enable vertical movement between floors. Moreover, ascending and descending between floors in a gravitational environment could pose unacceptable difficulty for the inhabitants under some circumstances. Another source of lack of design flexibility in a single toroidal inflatable structure is that for a given inflation pressure, an increase in the outer diameter of the structure necessarily entails an increase in the maximum stress in the structure. Because it is necessary to keep the maximum stress within the load-bearing capability of the structural materials, consistent with other aspects of the design, this may translate to a limit on the outer diameter. In an assembly comprising concentric nested toroidal structures, an increase in outer diameter does not necessarily entail an increase in height or a maximum stress in excess of the load-bearing capability of the structural

  9. Inside the complexity labyrinth

    NASA Astrophysics Data System (ADS)

    Fraser, Gordon

    2010-02-01

    Although the world we live in is complex, complexity as a science does not have a long history. For generations, most physicists tried to understand everything in terms of interactions between pairs of idealized "test particles". Then, about a 100 years ago, Henri Poincaré pointed out that a fully interacting three-body system was not just the sum of its three component pairs. The famous "three-body problem" was born.

  10. Electrospun complexes - functionalised nanofibres

    NASA Astrophysics Data System (ADS)

    Meyer, T.; Wolf, M.; Dreyer, B.; Unruh, D.; Krüger, C.; Menze, M.; Sindelar, R.; Klingelhöfer, G.; Renz, F.

    2016-12-01

    Here we present a new approach of using iron-complexes in electro-spun fibres. We modify poly(methyl methacrylate) (PMMA) by replacing the methoxy group with Diaminopropane or Ethylenediamine. The complex is bound covalently via an imine-bridge or an amide. The resulting polymer can be used in the electrospinning process without any further modifications in method either as pure reagent or mixed with small amounts of not functionalised polymer resulting in fibres of different qualities (Fig. 1).

  11. An erupted complex odontoma.

    PubMed

    Tozoglu, Sinan; Yildirim, Umran; Buyukkurt, M Cemil

    2010-01-01

    Odontomas are benign tumors of odontogenic origin. The cause of the odontoma is unknown, but it is believed to be hereditary or due to a disturbance in tooth development triggered by trauma or infection. Odontomas may be either compound or complex. Although these tumors are seen frequently, erupted odontomas are rare. The purpose of this study is to present a rare case of complex odontoma that erupted into the oral cavity.

  12. Atmospheric modeling in complex terrain

    SciTech Connect

    Williams, M. D.; Streit, G. E.

    1990-05-01

    Los Alamos investigators have developed several models which are relevant to modeling Mexico City air quality. The collection of models includes: meteorological models, dispersion models, air chemistry models, and visibility models. The models have been applied in several different contexts. They have been developed primarily to address the complexities posed by complex terrain. HOTMAC is the meteorological model which requires terrain and limited meteorological information. HOTMAC incorporates a relatively complete description of atmospheric physics to give good descriptions of the wind, temperature, and turbulence fields. RAPTAD is a dispersion code which uses random particle transport and kernel representations to efficiently provide accurate pollutant concentration fields. RAPTAD provides a much better description of tracer dispersion than do Gaussian puff models which fail to properly represent the effects of the wind profile near the surface. ATMOS and LAVM treat photochemistry and visibility respectively. ATMOS has been used to describe wintertime chemistry of the Denver brown cloud. Its description provided reasonable agreement with measurements for the high altitude of Denver. LAVM can provide both numerical indices or pictoral representations of visibility effects of pollutants. 15 refs., 74 figs.

  13. Determining Concentration of Nanoparticles from Ellipsometry

    NASA Technical Reports Server (NTRS)

    Venkatasubbarao, Srivatsa; Kempen, Lothar U.; Chipman, Russell

    2008-01-01

    A method of using ellipsometry or polarization analysis of light in total internal reflection of a surface to determine the number density of gold nanoparticles on a smooth substrate has been developed. The method can be modified to enable determination of densities of sparse distributions of nanoparticles in general, and is expected to be especially useful for measuring gold-nanoparticle-labeled biomolecules on microarrays. The method is based on theoretical calculations of the ellipsometric responses of gold nanoparticles. Elements of the calculations include the following: For simplicity, the gold nanoparticles are assumed to be spherical and to have the same radius. The distribution of gold nanoparticles is assumed to be a sub-monolayer (that is, sparser than a monolayer). The optical response of the sub-monolayer is modeled by use of a thin-island-film theory, according to which the polarizabilities parallel and perpendicular to the substrate are functions of the wavelength of light, the dielectric functions (permittivities expressed as complex functions of frequency or wavelength) of the gold and the suspending medium (in this case, the suspending medium is air), the fraction of the substrate area covered by the nanoparticles, and the radius of the nanoparticles. For the purpose of the thin-island-film theory, the dielectric function of the gold nanoparticles is modeled as the known dielectric function of bulk gold plus a correction term that is necessitated by the fact that the mean free path length for electrons in gold decreases with decreasing radius, in such a manner as to cause the imaginary part of the dielectric function to increase with decreasing radius (see figure). The correction term is a function of the nanoparticle radius, the wavelength of light, the mean free path and the Fermi speed of electrons in bulk gold, the plasma frequency of gold, and the speed of light in a vacuum. These models are used to calculate ellipsometric responses for

  14. Natural convection between concentric spheres

    NASA Technical Reports Server (NTRS)

    Garg, Vijay K.

    1992-01-01

    A finite-difference solution for steady natural convective flow in a concentric spherical annulus with isothermal walls has been obtained. The stream function-vorticity formulation of the equations of motion for the unsteady axisymmetric flow is used; interest lying in the final steady solution. Forward differences are used for the time derivatives and second-order central differences for the space derivatives. The alternating direction implicit method is used for solution of the discretization equations. Local one-dimensional grid adaptation is used to resolve the steep gradients in some regions of the flow at large Rayleigh numbers. The break-up into multi-cellular flow is found at high Rayleigh numbers for air and water, and at significantly low Rayleigh numbers for liquid metals. Excellent agreement with previous experimental and numerical data is obtained.

  15. [Concentration or decline in Puebla?].

    PubMed

    Cabrera Becerra, V

    1993-04-01

    Some doubts have been expressed over whether the slowing pace of urbanization suggested by the 1990 census of Mexico was an accurate reflection of changing conditions, or whether it resulted from some intentional or unintended bias. Comparison of data from succeeding censuses indicates that the growth rate of the city of Puebla declined from 6.32% in 1980 to 2.63% in 1990. This work argues that, in Puebla, a trend to deconcentration of the population within the city of Puebla during the 1980s was accompanied by rapid growth in smaller and medium sized nearby cities, resulting in increased overall concentration in Puebla's metropolitan area. The absolute population of the city of Puebla increased from 772,908 in 1980 to 1,007,170 in 1990. The central area of the state of Puebla, which surrounds the city, increased its share of the state population from 51.67% in 1980 to 52.21% in 1990. The number of places with over 5000 inhabitants in the area surrounding the city of Puebla increased from 27 in 1980 to 39 in 1990. Construction of the Puebla-Atlixco highway will undoubtedly attract growth to the area southwest of Puebla. Small cities to the east of Puebla have shown significant growth although their region remains strongly rural. The same process of deconcentration of population in Puebla and concentration in its surrounding metropolitan regions can probably also be detected in patterns of investment of public funds. The trend is likely to continue through the 1990s.

  16. The Rheology of Concentrated Suspensions

    SciTech Connect

    Andreas Acrivos

    2004-09-07

    Research program on the rheological properties of flowing suspensions. The primary purpose of the research supported by this grant was to study the flow characteristics of concentrated suspensions of non-colloidal solid particles and thereby construct a comprehensive and robust theoretical framework for modeling such systems quantitatively. At first glance, this seemed like a modest goal, not difficult to achieve, given that such suspensions were viewed simply as Newtonian fluids with an effective viscosity equal to the product of the viscosity of the suspending fluid times a function of the particle volume fraction. But thanks to the research findings of the Principal Investigator and of his Associates, made possible by the steady and continuous support which the PI received from the DOE Office of Basic Energy Sciences, the subject is now seen to be more complicated and therefore much more interesting in that concentrated suspensions have been shown to exhibit fascinating and unique rheological properties of their own that have no counterpart in flowing Newtonian or even non-Newtonian (polymeric) fluids. In fact, it is generally acknowledged that, as the result of these investigations for which the PI received the 2001 National Medal of Science, our understanding of how suspensions behave under flow is far more detailed and comprehensive than was the case even as recently as a decade ago. Thus, given that the flow of suspensions plays a crucial role in many diverse physical processes, our work has had a major and lasting impact in a subject having both fundamental as well as practical importance.

  17. Adjustment of urinary concentration to urinary volume in relation to erythrocyte and plasma concentrations: an evaluation of urinary heavy metals and organic substances

    SciTech Connect

    Araki, S.; Aono, H.; Murata, K.

    1986-05-01

    The effects of urinary volume on adjusted and nonadjusted urinary excretion of 11 heavy metals and organic substances were examined in relation to plasma and erythrocyte concentrations in 19 metal workers under conditions of water restriction and loading. Blood lead concentrations in these workers ranged from 25 to 59 micrograms/dl. The results indicated that: urinary volume significantly affects not only nonadjusted urinary concentration for all substances, but also affects timed excretion and concentrations adjusted to urinary specific gravity and to urinary creatinine for most substances; the concentration adjusted to urinary volume is, on the other hand, independent of urinary volume; and urinary excretion of lead and mercury is related more closely to erythrocyte concentration than to plasma concentration. This last finding reflects complex renal excretory mechanisms for these heavy metals.

  18. Conditions for duality between fluxes and concentrations in biochemical networks.

    PubMed

    Fleming, Ronan M T; Vlassis, Nikos; Thiele, Ines; Saunders, Michael A

    2016-11-21

    Mathematical and computational modelling of biochemical networks is often done in terms of either the concentrations of molecular species or the fluxes of biochemical reactions. When is mathematical modelling from either perspective equivalent to the other? Mathematical duality translates concepts, theorems or mathematical structures into other concepts, theorems or structures, in a one-to-one manner. We present a novel stoichiometric condition that is necessary and sufficient for duality between unidirectional fluxes and concentrations. Our numerical experiments, with computational models derived from a range of genome-scale biochemical networks, suggest that this flux-concentration duality is a pervasive property of biochemical networks. We also provide a combinatorial characterisation that is sufficient to ensure flux-concentration duality.The condition prescribes that, for every two disjoint sets of molecular species, there is at least one reaction complex that involves species from only one of the two sets. When unidirectional fluxes and molecular species concentrations are dual vectors, this implies that the behaviour of the corresponding biochemical network can be described entirely in terms of either concentrations or unidirectional fluxes.

  19. Polylogarithmic equilibrium treatment of molecular aggregation and critical concentrations.

    PubMed

    Michel, Denis; Ruelle, Philippe

    2017-02-15

    A full equilibrium treatment of molecular aggregation is presented for prototypes of 1D and 3D aggregates, with and without nucleation. By skipping complex kinetic parameters like aggregate size-dependent diffusion, the equilibrium treatment allows us to predict directly time-independent quantities such as critical concentrations. The relationships between the macroscopic equilibrium constants for different paths are first established by statistical corrections and so as to comply with the detailed balance constraints imposed by nucleation, and the composition of the mixture resulting from homogeneous aggregation is then analyzed using a polylogarithmic function. Several critical concentrations are distinguished: the residual monomer concentration at equilibrium (RMC) and the critical nucleation concentration (CNC), which is the threshold concentration of total subunits necessary for initiating aggregation. When increasing the concentration of total subunits, the RMC converges more strongly to its asymptotic value, the equilibrium constant of depolymerization, for 3D aggregates and in the case of nucleation. The CNC moderately depends on the number of subunits in the nucleus, but sharply increases with the difference between the equilibrium constants of polymerization and nucleation. As the RMC and CNC can be numerically but not analytically determined, ansatz equations connecting them to thermodynamic parameters are proposed.

  20. Quantifying intracellular hydrogen peroxide perturbations in terms of concentration

    PubMed Central

    Huang, Beijing K.; Sikes, Hadley D.

    2014-01-01

    Molecular level, mechanistic understanding of the roles of reactive oxygen species (ROS) in a variety of pathological conditions is hindered by the difficulties associated with determining the concentration of various ROS species. Here, we present an approach that converts fold-change in the signal from an intracellular sensor of hydrogen peroxide into changes in absolute concentration. The method uses extracellular additions of peroxide and an improved biochemical measurement of the gradient between extracellular and intracellular peroxide concentrations to calibrate the intracellular sensor. By measuring peroxiredoxin activity, we found that this gradient is 650-fold rather than the 7–10-fold that is widely cited. The resulting calibration is important for understanding the mass-action kinetics of complex networks of redox reactions, and it enables meaningful characterization and comparison of outputs from endogenous peroxide generating tools and therapeutics across studies. PMID:25460730