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Sample records for blood clot firmness

  1. Blood Clots

    Science.gov (United States)

    ... a doctor immediately. There have been many research advances that have improved the prevention and treatment of blood clots. Some current treatments include: Anticoagulants - medicine that prevents clots from forming Thrombolytics - medicine that ...

  2. Blood Clotting and Pregnancy

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    Full Text Available ... Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood Clots Blood Clotting and Pregnancy Clots and ... Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are Blood Clots ...

  3. Blood Clotting and Pregnancy

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    Full Text Available ... Toolkit Home For Patients Blood Disorders Blood Clots Blood Clotting & Pregnancy If you are pregnant, or you ... g., cancer, infection) back to top How are Blood Clots in Pregnant Women Treated? Typically, blood clots ...

  4. Blood Clotting and Pregnancy

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    Full Text Available ... For Patients Blood Disorders Blood Clots Blood Clotting & Pregnancy If you are pregnant, or you have just ... The risk of developing a blood clot during pregnancy is increased by the following: Previous blood clots ...

  5. Blood Clotting and Pregnancy

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    Full Text Available ... America Asia-Pacific Latin America Meeting on Hematologic Malignancies Gain knowledge, through “How I Treat” presentations, that ... Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood Clots Blood Clotting and Pregnancy Clots and ...

  6. Blood Clotting and Pregnancy

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    Full Text Available ... of articles from the 2017 ASH Annual Meeting Education Program Blood: How I Treat A compendium of Blood articles updated ... Clots Blood Clotting and Pregnancy Clots and Travel DVT Myths vs. Facts Blood ...

  7. Blood Clotting and Pregnancy

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    Full Text Available ... Blood Clots Blood Clotting and Pregnancy Clots and Travel DVT Myths vs. Facts Blood Disorder Fact Sheets ... that occurs when a DVT breaks off and travels to the blood vessels of the lungs. DVT ...

  8. Blood Clotting and Pregnancy

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    Full Text Available ... Hematology 2017 A collection of articles from the 2017 ASH Annual Meeting Education Program Blood: How I Treat A ... Disorders Blood Cancers Blood Clots Blood Clotting and Pregnancy Clots and ...

  9. Blood Clotting and Pregnancy

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    Full Text Available ... blood clots A genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) ... doctor's approval. Be aware of the signs and symptoms of a blood clot . Visit your doctor immediately ...

  10. Postpartum Blood Clots

    Science.gov (United States)

    ... Kidney Infections Breast Infection Postpartum Blood Clots Postpartum Thyroid Disorders Postpartum Depression The risk of developing blood clots ( ... Kidney Infections Breast Infection Postpartum Blood Clots Postpartum Thyroid Disorders Postpartum Depression NOTE: This is the Consumer Version. ...

  11. Blood Clotting and Pregnancy

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    Full Text Available ... This Section Action Alerts Advocacy Toolkit Policy News Sickle Cell Disease Initiative Policy Statements Congressional Fellowship Testimony and ... all publications For Patients Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood Clots Blood Clotting ...

  12. Blood Clotting and Pregnancy

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    Full Text Available ... illness (e.g., cancer, infection) back to top How are Blood Clots in Pregnant Women Treated? Typically, blood clots are treated with an anticoagulant, a medicine that prevents the blood from clotting. Certain anticoagulants are safe to use during pregnancy. back to top Are Blood Clots ...

  13. Blood Clotting and Pregnancy

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    Full Text Available ... with Your Doctor Patient Group Links Advocacy Toolkit Home For Patients Blood Disorders Blood Clots Blood Clotting & ... Programs and Awards ASH Agenda for Hematology Research Education For Clinicians For Trainees For Educators For Patients ...

  14. Blood Clotting and Pregnancy

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    Full Text Available ... an immediate impact on your practice Summit on Emerging Immunotherapies Registration Schedule & Program Meeting on Lymphoma Biology ... blood clots are treated with an anticoagulant, a medicine that prevents the blood from clotting. Certain anticoagulants ...

  15. Blood Clotting and Pregnancy

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    Full Text Available ... to top How are Blood Clots in Pregnant Women Treated? Typically, blood clots are treated with an ... Programs and Awards ASH Agenda for Hematology Research Education For Clinicians For Trainees For Educators For Patients ...

  16. Blood Clotting and Pregnancy

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    Full Text Available ... blood clots A genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) back ...

  17. Blood Clotting and Pregnancy

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    Full Text Available ... pregnancy: Be aware of risk factors. Know your family history. Make sure your doctor knows about any ... blood clots or blood clotting disorders in your family. Remain active, with your doctor's approval. Be aware ...

  18. Blood Clotting and Pregnancy

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    Full Text Available ... In This Section Agenda for Hematology Research Precision Medicine Initiative Research Registry Research Recommendations Research Programs and ... blood clots are treated with an anticoagulant, a medicine that prevents the blood from clotting. Certain anticoagulants ...

  19. Blood Clotting and Pregnancy

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    Full Text Available ... these blood conditions and increase research on the causes, prevention, and treatment. Blood clots are also potentially ... immobility (e.g., bedrest, long distance travel) ...

  20. Blood Clotting and Pregnancy

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    Full Text Available ... Be aware of risk factors. Know your family history. Make sure your doctor knows about any history of blood clots or blood clotting disorders in ... you are interested in learning more about blood diseases and disorders, here are a few other resources ...

  1. Blood Clotting and Pregnancy

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    Full Text Available ... Be aware of risk factors. Know your family history. Make sure your doctor knows about any history of blood clots or blood clotting disorders in ... Programs and Awards ASH Agenda for Hematology Research Education For Clinicians For Trainees For Educators For Patients ...

  2. Blood Clotting and Pregnancy

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    Full Text Available ... known as venous thromboembolism, are highly preventable (see prevention tips below). The U.S. Surgeon General has issued ... blood conditions and increase research on the causes, prevention, and treatment. Blood clots are also potentially dangerous ...

  3. Blood Clotting and Pregnancy

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    Full Text Available ... predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are Blood ...

  4. Blood Clotting and Pregnancy

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    Full Text Available ... A genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births ... treating blood conditions. back to top Antiphospholipid Antibody Syndrome: A Patient's Journey back to top Where Can ...

  5. Blood Clotting and Pregnancy

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    Full Text Available ... Apps Share Your Idea Donate My Account Search Show Main Menu + About Awards Membership ASH Foundation Global ... are pregnant and have concerns about blood clots, talk with your doctor about your risks and prevention. ...

  6. Blood Clotting and Pregnancy

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    Full Text Available ... Your Idea Donate My Account Search Show Main Menu + About Awards Membership ASH Foundation Global Initiatives Newsroom ... genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased ...

  7. Blood Clotting and Pregnancy

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    Full Text Available ... genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are ...

  8. National Blood Clot Alliance

    Science.gov (United States)

    ... Pregnancy & Childbirth Treatment of Menopause Symptoms Women’s Health Menopause and Hormone Replacement Therapy FAQs Blood Clots and Women’s Health ... Family Planning, Pregnancy & Childbirth, and the onset of Menopause Symptoms that might be treated ... therapy. Learn More The public health impact of ...

  9. Blood Clotting and Pregnancy

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    Full Text Available ... clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical ... Programs and Awards ASH Agenda for Hematology Research Education For Clinicians For Trainees For Educators For Patients ...

  10. Blood Clotting and Pregnancy

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    Full Text Available ... Clotting & Pregnancy If you are pregnant, or you have just had a baby, you are at greater ... Visit your doctor immediately if you think you have one. If you are pregnant and have concerns ...

  11. Blood Clotting and Pregnancy

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    Full Text Available ... Schedule & Program Registration Receipts Abstracts View all meetings Publications Blood Current Issue First Edition Abstracts Blood Advances ... reflect the most recent scientific research View all publications For Patients Blood Basics Blood Disorders Anemia Bleeding ...

  12. Blood Clotting and Pregnancy

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    Full Text Available ... all Blood Current Issue First Edition Abstracts Blood Advances A peer-reviewed journal with a unique focus ... Publications Blood Current Issue First Edition Abstracts Blood Advances A peer-reviewed, online only, open access journal ...

  13. Blood Clotting and Pregnancy

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    Full Text Available ... scientific research View all publications For Patients Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood ... that provide information. back to top ASH Foundation Support the mission of ASH and help move hematology ...

  14. Blood Clotting and Pregnancy

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    Full Text Available ... Research Programs and Awards View all Blood Current Issue First Edition Abstracts Blood Advances A peer-reviewed ... Receipts Abstracts View all meetings Publications Blood Current Issue First Edition Abstracts Blood Advances A peer-reviewed, ...

  15. Blood Clotting and Pregnancy

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    Full Text Available ... Blood articles updated to reflect the most recent scientific research View all publications For Patients Blood Basics ... help: Results of Clinical Studies Published in Blood Search Blood , the official journal of ASH, for the ...

  16. Blood Clotting and Pregnancy

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    Full Text Available ... that may be of some help: Results of Clinical Studies Published in Blood Search Blood , the official journal of ASH, for the results of the latest blood research. While recent articles generally require a subscriber login, ...

  17. Blood Clotting and Pregnancy

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    Full Text Available ... to Action on DVT and PE to raise public awareness of these blood conditions and increase research ... may be of some help: Results of Clinical Studies Published in Blood Search Blood , the official journal ...

  18. Blood Clotting and Pregnancy

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    Full Text Available ... Studies Published in Blood Search Blood , the official journal of ASH, for the results of the latest blood research. While recent articles generally require a subscriber login, patients interested in ...

  19. Blood Clotting and Pregnancy

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    Full Text Available ... in the field Hematology 2017 A collection of articles from the 2017 ASH Annual Meeting Education Program Blood: How I Treat A compendium of Blood articles updated to reflect the most recent scientific research ...

  20. Blood Clotting and Pregnancy

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    Full Text Available ... a subscriber login, patients interested in viewing an access-controlled article in Blood may obtain a copy by e-mailing a request to the Blood ... ASH Foundation Support the mission ...

  1. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... In This Section Agenda for Hematology Research Precision Medicine Initiative Research Registry Research Recommendations Research Programs and Awards View all Blood Current Issue First Edition Abstracts Blood Advances A peer-reviewed journal with a unique focus ...

  2. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... articles from the 2017 ASH Annual Meeting Education Program Blood: How I Treat A compendium of Blood articles updated ... Doctor Patient Group Links Advocacy Toolkit Home For Patients ...

  3. Blood Clotting and Pregnancy

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    Full Text Available ... Blood Advances A peer-reviewed, online only, open access journal with a unique focus on scholarly and ... a subscriber login, patients interested in viewing an access-controlled article in Blood may obtain a copy ...

  4. Blood Clotting and Pregnancy

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    Full Text Available ... ASH Apps Share Your Idea Donate My Account Search Show Main Menu + About Awards Membership ASH Foundation ... help: Results of Clinical Studies Published in Blood Search Blood , the official journal of ASH, for the ...

  5. Blood Clotting and Pregnancy

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    Full Text Available ... Current Issue First Edition Abstracts Blood Advances A peer-reviewed journal with a unique focus on scholarly ... Current Issue First Edition Abstracts Blood Advances A peer-reviewed, online only, open access journal with a ...

  6. Blood Clotting and Pregnancy

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    Full Text Available ... 4, 2018 2017 Resources CME & Certificates Schedule & Program Registration Receipts Abstracts View all meetings Publications Blood Current Issue First Edition Abstracts Blood Advances A peer-reviewed, online only, open access journal with a unique focus ...

  7. Blood Clotting and Pregnancy

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    Full Text Available ... Emerging Immunotherapies Registration Schedule & Program Meeting on Lymphoma Biology Registration Schedule & Program Abstracts 60th ASH Annual Meeting & ... Malignancies Consultative Hematology Course ASH Meeting on Lymphoma Biology ASH Workshop on Genome Editing Publications Blood Blood ...

  8. Blood Clotting and Pregnancy

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    Full Text Available ... Section Action Alerts Advocacy Toolkit Policy News Sickle Cell Disease Initiative Policy Statements Congressional Fellowship Testimony and ... Malignancies Consultative Hematology Course ASH Meeting on Lymphoma Biology ASH Workshop on Genome Editing Publications Blood Blood ...

  9. Blood Clotting and Pregnancy

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    Full Text Available ... copy by e-mailing a request to the Blood Publishing Office . Patient Groups A list of Web links to patient groups and other organizations that provide information. back to top ASH ... Blood Blood Advances The Hematologist ASH Clinical News ASH ...

  10. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... that may be of some help: Results of Clinical Studies Published in Blood Search Blood , the official journal of ASH, for the results of the latest blood research. While recent articles generally require a subscriber login, patients interested in ...

  11. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... online only, open access journal with a unique focus on scholarly and educational content The Hematologist ... Group Links Advocacy Toolkit Home For Patients Blood Disorders ...

  12. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... login, patients interested in viewing an access-controlled article in Blood may obtain a copy by e-mailing a request to the Blood Publishing Office . Patient Groups A list of Web links to patient groups and other organizations that provide information. back to top ASH Foundation Support the mission ...

  13. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... educational meetings and webinars ASH Image Bank Educational Web-based library of hematologic imagery In This Section: ... Blood Publishing Office . Patient Groups A list of Web links to patient groups and other organizations that ...

  14. Blood Clotting and Pregnancy

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    Full Text Available ... Current Issue First Edition Abstracts Blood Advances A peer-reviewed journal with a unique focus on scholarly and educational content Annual Meeting Abstracts Call for Abstracts Abstract Review Categories Abstracts Archive View all Education ASH Academy ...

  15. Blood Clotting and Pregnancy

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    Full Text Available ... for Hematology Research Research Registry Research Recommendations Research Programs and Awards View all Blood Current Issue First ... for continuing medical education (CME) and recertification Educational Programs Programs to enhance knowledge, research, and expertise Advocacy ...

  16. Blood Clotting and Pregnancy

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    Full Text Available ... content Annual Meeting Abstracts Call for Abstracts Abstract Review Categories Abstracts Archive View all Education ASH Academy ... First Edition Abstracts Blood Advances A peer-reviewed, online only, open access journal with a unique focus ...

  17. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... If you find that you are interested in learning more about blood diseases and disorders, here are ... mission of ASH and help move hematology forward. Learn more Find a Hematologist Search a database of ...

  18. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... and webinars ASH Image Bank Educational Web-based library of hematologic imagery In This Section: Resources for ... to Action on DVT and PE to raise public awareness of these blood conditions and increase research ...

  19. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Advocacy Toolkit Policy News Sickle Cell Disease Initiative Policy ... Surgeon General has issued a Call to Action on DVT and PE to raise public awareness of these blood conditions and increase research ...

  20. Blood Clotting and Pregnancy

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    Full Text Available ... If you find that you are interested in learning more about blood diseases and disorders, here are ... Membership ASH Foundation Global Initiatives Newsroom facebook twitter youtube linkedin Copyright © 2018 by American Society of Hematology ...

  1. Blood Clotting and Pregnancy

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    Full Text Available ... bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) back ... a request to the Blood Publishing Office . Patient Groups A list of Web links to patient groups ...

  2. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... First Edition Abstracts Blood Advances A peer-reviewed journal with a unique focus on scholarly and educational ... Advances A peer-reviewed, online only, open access journal with a unique focus on scholarly and educational ...

  3. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... condition is known as deep vein thrombosis (DVT). Pulmonary embolism (PE) is a life-threatening event that ... and travels to the blood vessels of the lungs. DVT and PE, collectively known as venous thromboembolism, ...

  4. Blood Clotting and Pregnancy

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    Full Text Available ... If you find that you are interested in learning more about blood diseases and disorders, here are ... of Web links to patient groups and other organizations that provide information. back to top ASH Foundation ...

  5. Blood Clotting and Pregnancy

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    Full Text Available ... blood conditions. back to top Antiphospholipid Antibody Syndrome: A Patient's Journey back to top Where Can I ... and help move hematology forward. Learn more Find a Hematologist Search a database of practicing hematologists in ...

  6. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Action Alerts Advocacy Toolkit Policy News Sickle Cell Disease Initiative Policy Statements Congressional Fellowship Testimony and Correspondence ... you are interested in learning more about blood diseases and disorders, here are a few other resources ...

  7. Blood Clotting and Pregnancy

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    Full Text Available ... If you find that you are interested in learning more about blood diseases and disorders, here are ... Programs and Awards ASH Agenda for Hematology Research Education For Clinicians For Trainees For Educators For Patients ...

  8. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Assessment Program A comprehensive resource to help stay current with the latest advances in the field Hematology 2017 A collection of articles from the 2017 ASH Annual Meeting Education Program Blood: How I Treat A compendium of ...

  9. Blood Clotting and Pregnancy

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    Full Text Available ... Clinical News Society News Clinical News Features ASH Self-Assessment Program A comprehensive resource to help stay ... Blood Advances The Hematologist ASH Clinical News ASH Self-Assessment Program Hematology , ASH Education Program About Awards ...

  10. Blood Clotting and Pregnancy

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    Full Text Available ... Current Issue First Edition Abstracts Blood Advances A peer-reviewed journal with a unique focus on scholarly and educational content Annual Meeting Abstracts Call for Abstracts Abstract Review Categories Abstracts Archive View all Education ASH Academy The eLearning platform for hematologists ASH ...

  11. Blood Clotting and Pregnancy

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    Full Text Available ... Clinical News Society News Clinical News Features ASH Self-Assessment Program A comprehensive resource to help stay current ... Blood Advances The Hematologist ASH Clinical News ASH Self-Assessment Program Hematology , ASH Education Program About Awards Membership ...

  12. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Blood Advances A peer-reviewed, online only, open access journal with a unique focus on scholarly and educational content The Hematologist Features Diffusion President's Column ASH Clinical News Society News Clinical News Features ASH Self-Assessment Program A comprehensive resource to help stay ...

  13. Blood clot detection using magnetic nanoparticles

    Science.gov (United States)

    Khurshid, Hafsa; Friedman, Bruce; Berwin, Brent; Shi, Yipeng; Ness, Dylan B.; Weaver, John B.

    2017-05-01

    Deep vein thrombosis, the development of blood clots in the peripheral veins, is a very serious, life threatening condition that is prevalent in the elderly. To deliver proper treatment that enhances the survival rate, it is very important to detect thrombi early and at the point of care. We explored the ability of magnetic particle spectroscopy (MSB) to detect thrombus via specific binding of aptamer functionalized magnetic nanoparticles with the blood clot. MSB uses the harmonics produced by nanoparticles in an alternating magnetic field to measure the rotational freedom and, therefore, the bound state of the nanoparticles. The nanoparticles' relaxation time for Brownian rotation increases when bound [A.M. Rauwerdink and J. B. Weaver, Appl. Phys. Lett. 96, 1 (2010)]. The relaxation time can therefore be used to characterize the nanoparticle binding to thrombin in the blood clot. For longer relaxation times, the approach to saturation is more gradual reducing the higher harmonics and the harmonic ratio. The harmonic ratios of nanoparticles conjugated with anti-thrombin aptamers (ATP) decrease significantly over time with blood clot present in the sample medium, compared with nanoparticles without ATP. Moreover, the blood clot removed from the sample medium produced a significant MSB signal, indicating the nanoparticles are immobilized on the clot. Our results show that MSB could be a very useful non-invasive, quick tool to detect blood clots at the point of care so proper treatment can be used to reduce the risks inherent in deep vein thrombosis.

  14. Blood Clotting Inspired Polymer Physics

    Science.gov (United States)

    Sing, Charles Edward

    The blood clotting process is one of the human body's masterpieces in targeted molecular manipulation, as it requires the activation of the clotting cascade at a specific place and a specific time. Recent research in the biological sciences have discovered that one of the protein molecules involved in the initial stages of the clotting response, von Willebrand Factor (vWF), exhibits counterintuitive and technologically useful properties that are driven in part by the physical environment in the bloodstream at the site of a wound. In this thesis, we take inspiration from initial observations of the vWF in experiments, and aim to describe the behaviors observed in this process within the context of polymer physics. By understanding these physical principles, we hope to harness nature's ability to both direct molecules in both spatial and conformational coordinates. This thesis is presented in three complementary sections. After an initial introduction describing the systems of interest, we first describe the behavior of collapsed Lennard-Jones polymers in the presence of an infinite medium. It has been shown that simple bead-spring homopolymer models describe vWF quite well in vitro. We build upon this previous work to first describe the behavior of a collapsed homopolymer in an elongational fluid flow. Through a nucleation-protrusion mechanism, scaling relationships can be developed to provide a clear picture of a first-order globule-stretch transition and its ramifications in dilute-solution rheology. The implications of this behavior and its relation to the current literature provides qualitative explanations for the physiological process of vasoconstriction. In an effort to generalize these observations, we present an entire theory on the behavior of polymer globules under influence of any local fluid flow. Finally, we investigate the internal dynamics of these globules by probing their pulling response in an analogous fashion to force spectroscopy. We elucidate

  15. Blood Thinners: Can I Still Get Blood Clots?

    Science.gov (United States)

    ... get blood clots? If you're taking a blood thinner, is it still possible to get a blood clot? Answers from Rekha Mankad, M.D. Yes. Medications that are commonly called blood thinners — such as aspirin, warfarin (Coumadin, Jantoven), dabigatran ( ...

  16. A rat model of reproducible cerebral infarction using thrombotic blood clot emboli

    DEFF Research Database (Denmark)

    Overgaard, K.; Sereghy, T.; Boysen, G.

    1992-01-01

    Neuropathology, experimental thromboembolism, stroke, blood flow, in vitro thrombotic clotting, cerebral infarction, rat......Neuropathology, experimental thromboembolism, stroke, blood flow, in vitro thrombotic clotting, cerebral infarction, rat...

  17. Limitations of using synthetic blood clots for measuring in vitro clot capture efficiency of inferior vena cava filters

    Directory of Open Access Journals (Sweden)

    Robinson RA

    2013-05-01

    Full Text Available Ronald A Robinson, Luke H Herbertson, Srilekha Sarkar Das, Richard A Malinauskas, William F Pritchard, Laurence W GrossmanOffice of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, MD, USAAbstract: The purpose of this study was first to evaluate the clot capture efficiency and capture location of six currently-marketed vena cava filters in a physiological venous flow loop, using synthetic polyacrylamide hydrogel clots, which were intended to simulate actual blood clots. After observing a measured anomaly for one of the test filters, we redirected the focus of the study to identify the cause of poor clot capture performance for large synthetic hydrogel clots. We hypothesized that the uncharacteristic low clot capture efficiency observed when testing the outlying filter can be attributed to the inadvertent use of dense, stiff synthetic hydrogel clots, and not as a result of the filter design or filter orientation. To study this issue, sheep blood clots and polyacrylamide (PA synthetic clots were injected into a mock venous flow loop containing a clinical inferior vena cava (IVC filter, and their captures were observed. Testing was performed with clots of various diameters (3.2, 4.8, and 6.4 mm, length-to-diameter ratios (1:1, 3:1, 10:1, and stiffness. By adjusting the chemical formulation, PA clots were fabricated to be soft, moderately stiff, or stiff with elastic moduli of 805 ± 2, 1696 ± 10 and 3295 ± 37 Pa, respectively. In comparison, the elastic moduli for freshly prepared sheep blood clots were 1690 ± 360 Pa. The outlying filter had a design that was characterized by peripheral gaps (up to 14 mm between its wire struts. While a low clot capture rate was observed using large, stiff synthetic clots, the filter effectively captured similarly sized sheep blood clots and soft PA clots. Because the stiffer synthetic clots remained straight when approaching the

  18. Comparison of standard fibrinogen measurement methods with fibrin clot firmness assessed by thromboelastometry in patients with cirrhosis.

    Science.gov (United States)

    Vucelic, Dragica; Jesic, Rada; Jovicic, Snezana; Zivotic, Maja; Grubor, Nikica; Trajkovic, Goran; Canic, Ivana; Elezovic, Ivo; Antovic, Aleksandra

    2015-06-01

    The Clauss fibrinogen method and thrombin clotting time (TCT) are still routinely used in patients with cirrhosis to define fibrinogen concentration and clotting potential. The thromboelastometric functional fibrinogen FIBTEM assay evaluates the strength of fibrin-based clots in whole blood, providing information on both quantitative deficit and fibrin polymerization disorders. To compare these three methods of assessing fibrinogen in patients with cirrhosis of different aetiologies, characterized by impairment in fibrinogen concentration as well as functional aberrance. Sixty patients with alcoholic and 24 patients with cholestatic cirrhosis were included (Child-Pugh score (CPs)A, n=24; B, n=32; C, n=28). All parameters were compared with those from a control group. Maximum clot firmness (MCF) in the FIBTEM test was assessed in regard to its relevance in detection of qualitative fibrinogen disorders in comparison with results obtained by standard measurement methods, i.e. the Clauss fibrinogen method and TCT. With increased cirrhosis severity, fibrinogen and FIBTEM-MCF levels significantly declined (p=0.002), while TCT was significantly prolonged (p=0.002). In all CPs groups, fibrinogen strongly correlated with FIBTEM-MCF (r=0.77, r=0.72, r=0.74; pmeasurement in cirrhotic patients, especially in evaluating fibrin polymerization disorders in these patients. Further studies are needed to evaluate the usefulness of this assay in predicting bleeding complications in cirrhotic patients as well as monitoring replacement treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Limitations of using synthetic blood clots for measuring in vitro clot capture efficiency of inferior vena cava filters.

    Science.gov (United States)

    Robinson, Ronald A; Herbertson, Luke H; Sarkar Das, Srilekha; Malinauskas, Richard A; Pritchard, William F; Grossman, Laurence W

    2013-01-01

    The purpose of this study was first to evaluate the clot capture efficiency and capture location of six currently-marketed vena cava filters in a physiological venous flow loop, using synthetic polyacrylamide hydrogel clots, which were intended to simulate actual blood clots. After observing a measured anomaly for one of the test filters, we redirected the focus of the study to identify the cause of poor clot capture performance for large synthetic hydrogel clots. We hypothesized that the uncharacteristic low clot capture efficiency observed when testing the outlying filter can be attributed to the inadvertent use of dense, stiff synthetic hydrogel clots, and not as a result of the filter design or filter orientation. To study this issue, sheep blood clots and polyacrylamide (PA) synthetic clots were injected into a mock venous flow loop containing a clinical inferior vena cava (IVC) filter, and their captures were observed. Testing was performed with clots of various diameters (3.2, 4.8, and 6.4 mm), length-to-diameter ratios (1:1, 3:1, 10:1), and stiffness. By adjusting the chemical formulation, PA clots were fabricated to be soft, moderately stiff, or stiff with elastic moduli of 805 ± 2, 1696 ± 10 and 3295 ± 37 Pa, respectively. In comparison, the elastic moduli for freshly prepared sheep blood clots were 1690 ± 360 Pa. The outlying filter had a design that was characterized by peripheral gaps (up to 14 mm) between its wire struts. While a low clot capture rate was observed using large, stiff synthetic clots, the filter effectively captured similarly sized sheep blood clots and soft PA clots. Because the stiffer synthetic clots remained straight when approaching the filter in the IVC model flow loop, they were more likely to pass between the peripheral filter struts, while the softer, physiological clots tended to fold and were captured by the filter. These experiments demonstrated that if synthetic clots are used as a surrogate for animal or human blood

  20. Elasticity and fracture strain of whole blood clots

    Czech Academy of Sciences Publication Activity Database

    Říha, Pavel; Wang, X.; Liao, R.; Stoltz, J. F.

    1999-01-01

    Roč. 21, č. 1 (1999), s. 45-49 ISSN 1386-0291 Institutional research plan: CEZ:AV0Z2060917 Keywords : viscoelasticity * fracture strain * blood clots Subject RIV: BK - Fluid Dynamics Impact factor: 0.395, year: 1999

  1. 21 CFR 864.7140 - Activated whole blood clotting time tests.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Activated whole blood clotting time tests. 864....7140 Activated whole blood clotting time tests. (a) Identification. An activated whole blood clotting time tests is a device, used to monitor heparin therapy for the treatment of venous thrombosis or...

  2. Blood clotting and platelets: a delicate balance

    International Nuclear Information System (INIS)

    Heyns, A. du P.; Loetter, M.G.; Badenhorst, P.N.

    1988-01-01

    The Medical Research Council Blood Platelet Research Unit has studied many of the facets of platelets. The research highlights of the Unit include the following: the identification of ADPase, an enzyme found in the blood vessel wall, which breaks down adenosine diphospate (ADP) to adenosine, and which inhibits platelet aggregation; the determination of the relationship between the biochemical activity of the vessel wall with the development of atherosclerosis; the development of a method to label platelets with the compound In-111-oxine; the use of labelled platelets to study platelets in the spleen: an investigation of the life-span of platelets, which revealed how aged platelets are removed from circulation, and recently a study of methods to demonstrate in vivo activation of platelets. 1 fig

  3. Seamless particle-based modeling of blood clotting

    Science.gov (United States)

    Yazdani, Alireza; Karniadakis, George

    2016-11-01

    We propose a new multiscale framework that seamlessly integrate four key components of blood clotting namely, blood rheology, cell mechanics, coagulation kinetics and transport of species and platelet adhesive dynamics. We use transport dissipative particle dynamics (tDPD) which is an extended form of original DPD as the base solver to model both blood flow and the reactive transport of chemical species in the coagulation cascade. Further, we use a coarse-grained representation of blood cell's membrane that accounts for its mechanics; both red blood cells and platelets are resolved at sub-cellular resolution, and stochastic bond formation/dissociation are included to account for platelet adhesive dynamics at the site of injury. Our results show good qualitative agreement with in vivo experiments. The numerical framework allows us to perform systematic analysis on different mechanisms of blood clotting. In addition, this new multiscale particle-based methodology can open new directions in addressing different biological processes from sub-cellular to macroscopic scales. NIH Grant No. U01HL116323.

  4. Adenosine diphosphate-decorated chitosan nanoparticles shorten blood clotting times, influencing the structures and varying the mechanical properties of the clots

    Science.gov (United States)

    Chung, Tze-Wen; Lin, Pei-Yi; Wang, Shoei-Shen; Chen, Yen-Fung

    2014-01-01

    Chitosan nanoparticles (NPs) decorated with adenosine diphosphate (ADP) (ANPs) or fibrinogen (FNPs) were used to fabricate hemostatic NPs that can shorten blood clotting time and prevent severe local hemorrhage. The structure and mechanical properties of the blood clot induced with ANP (clot/ANP) or FNP (clot/FNP) were also investigated. The NPs, ANPs, and FNPs, which had particle sizes of 245.1±14.0, 251.0±9.8, and 326.5±14.5 nm and zeta potentials of 24.1±0.5, 20.6±1.9, and 15.3±1.5 mV (n=4), respectively, were fabricated by ionic gelation and then decorated with ADP and fibrinogen. The zeta potentials and Fourier transform infrared (FTIR) spectroscopy of the NPs confirmed that their surfaces were successfully coated with ADP and fibrinogen. The scanning electron microscope (SEM) micrographs of the structure of the clot induced with “undecorated” chitosan NPs (clot/NP), clot/ANP, and clot/FNP (at 0.05 wt%) were different, after citrated bloods had been recalcified by a calcium chloride solution containing NPs, ANPs, or FNPs. This indicated that many NPs adhered on the membrane surfaces of red blood cells, that ANPs induced many platelet aggregates, and that FNPs were incorporated into the fibrin network in the clots. Measurements of the blood clotting times (Tc) of blood clot/NPs, clot/ANPs, and clot/FNPs, based on 90% of ultimate frequency shifts measured on a quartz crystal microbalance (QCM), were significantly (P<0.05) (n=4) shorter than that of a clot induced by a phosphate-buffered solution (PBS) (clot/PBS) (63.6%±3.1%, 48.3%±6.2%, and 63.2%±4.7%, respectively). The ΔF2 values in the spectra of frequency shifts associated with the propagation of fibrin networks in the clot/ANPs and clot/FNPs were significantly lower than those of clot/PBS. Interestingly, texture profile analysis of the compressional properties showed significantly lower hardness and compressibility in clot/NPs and clot/ANPs (P<0.05 or better) (n=4) compared with clot/PBS and

  5. Procoagulant control strategies for the human blood clotting process.

    Science.gov (United States)

    Laurino, Marco; Menara, Tommaso; Stella, Alessandro; Betta, Monica; Landi, Alberto

    2015-08-01

    This paper describes the comparison between two drug control strategies to hemophilia A. To emulate blood clotting and the pathological condition of hemophilia, a mathematical model composed by 14 ordinary differential equations is considered. We adopt a variable structure non-linear PID approach and a Model Predictive Control in order to control the dosage of procoagulant factor used in the treatment of hemophiliac patient. The two control actions are sampled for a practical application. Finally, we discuss and compare the results of the two control approaches, introducing a suited control index (eINR).

  6. Capture of lipopolysaccharide (endotoxin by the blood clot: a comparative study.

    Directory of Open Access Journals (Sweden)

    Margaret T Armstrong

    Full Text Available In vertebrates and arthropods, blood clotting involves the establishment of a plug of aggregated thrombocytes (the cellular clot and an extracellular fibrillar clot formed by the polymerization of the structural protein of the clot, which is fibrin in mammals, plasma lipoprotein in crustaceans, and coagulin in the horseshoe crab, Limulus polyphemus. Both elements of the clot function to staunch bleeding. Additionally, the extracellular clot functions as an agent of the innate immune system by providing a passive anti-microbial barrier and microbial entrapment device, which functions directly at the site of wounds to the integument. Here we show that, in addition to these passive functions in immunity, the plasma lipoprotein clot of lobster, the coagulin clot of Limulus, and both the platelet thrombus and the fibrin clot of mammals (human, mouse operate to capture lipopolysaccharide (LPS, endotoxin. The lipid A core of LPS is the principal agent of gram-negative septicemia, which is responsible for more than 100,000 human deaths annually in the United States and is similarly toxic to arthropods. Quantification using the Limulus Amebocyte Lysate (LAL test shows that clots capture significant quantities of LPS and fluorescent-labeled LPS can be seen by microscopy to decorate the clot fibrils. Thrombi generated in the living mouse accumulate LPS in vivo. It is suggested that capture of LPS released from gram-negative bacteria entrapped by the blood clot operates to protect against the disease that might be caused by its systemic dispersal.

  7. 42 CFR 410.63 - Hepatitis B vaccine and blood clotting factors: Conditions.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 2 2010-10-01 2010-10-01 false Hepatitis B vaccine and blood clotting factors... Other Health Services § 410.63 Hepatitis B vaccine and blood clotting factors: Conditions... under § 410.10, subject to the specified conditions: (a) Hepatitis B vaccine: Conditions. Effective...

  8. Blood Clots That Kill: Preventing DVT | NIH MedlinePlus the Magazine

    Science.gov (United States)

    ... clot. This also is true of treatment with hormone therapy or birth control pills. Sometimes, blood clots can form from no known cause. Risk Many factors increase your risk for deep vein thrombosis (DVT). They include: A history of DVT. Disorders or factors that make your ...

  9. Review of numerical methods for simulation of mechanical heart valves and the potential for blood clotting.

    Science.gov (United States)

    Zakaria, Mohamad Shukri; Ismail, Farzad; Tamagawa, Masaaki; Aziz, Ahmad Fazli Abdul; Wiriadidjaja, Surjatin; Basri, Adi Azrif; Ahmad, Kamarul Arifin

    2017-09-01

    Even though the mechanical heart valve (MHV) has been used routinely in clinical practice for over 60 years, the occurrence of serious complications such as blood clotting remains to be elucidated. This paper reviews the progress that has been made over the years in terms of numerical simulation method and the contribution of abnormal flow toward blood clotting from MHVs in the aortic position. It is believed that this review would likely be of interest to some readers in various disciplines, such as engineers, scientists, mathematicians and surgeons, to understand the phenomenon of blood clotting in MHVs through computational fluid dynamics.

  10. Adenosine diphosphate-decorated chitosan nanoparticles shorten blood clotting times, influencing the structures and varying the mechanical properties of the clots

    Directory of Open Access Journals (Sweden)

    Chung TW

    2014-03-01

    Full Text Available Tze-Wen Chung,1,3 Pei-Yi Lin,2 Shoei-Shen Wang,2 Yen-Fung Chen31Department of Biomedical Engineering, National Yang-Ming University, 2Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan, Republic of China; 3Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology, Yunlin, Taiwan, Republic of ChinaAbstract: Chitosan nanoparticles (NPs decorated with adenosine diphosphate (ADP (ANPs or fibrinogen (FNPs were used to fabricate hemostatic NPs that can shorten blood clotting time and prevent severe local hemorrhage. The structure and mechanical properties of the blood clot induced with ANP (clot/ANP or FNP (clot/FNP were also investigated. The NPs, ANPs, and FNPs, which had particle sizes of 245.1±14.0, 251.0±9.8, and 326.5±14.5 nm and zeta potentials of 24.1±0.5, 20.6±1.9, and 15.3±1.5 mV (n=4, respectively, were fabricated by ionic gelation and then decorated with ADP and fibrinogen. The zeta potentials and Fourier transform infrared (FTIR spectroscopy of the NPs confirmed that their surfaces were successfully coated with ADP and fibrinogen. The scanning electron microscope (SEM micrographs of the structure of the clot induced with "undecorated" chitosan NPs (clot/NP, clot/ANP, and clot/FNP (at 0.05 wt% were different, after citrated bloods had been recalcified by a calcium chloride solution containing NPs, ANPs, or FNPs. This indicated that many NPs adhered on the membrane surfaces of red blood cells, that ANPs induced many platelet aggregates, and that FNPs were incorporated into the fibrin network in the clots. Measurements of the blood clotting times (Tc of blood clot/NPs, clot/ANPs, and clot/FNPs, based on 90% of ultimate frequency shifts measured on a quartz crystal microbalance (QCM, were significantly (P<0.05 (n=4 shorter than that of a clot induced by a phosphate-buffered solution (PBS (clot/PBS (63.6%±3.1%, 48.3%±6.2%, and 63.2%±4.7%, respectively. The ∆F2

  11. Iodine based radiopacity of experimental blood clots for testing of mechanical thrombectomy devices

    International Nuclear Information System (INIS)

    Luo, Zhong Hua; Chung, Alex; Choi, Gibok; Lin, Yih Huie; Pang, Huajin; Uchida, Barry T.; Pavcnik, Dusan; Jeromel, Miran; Keller, Frederick S.; Rösch, Josef

    2013-01-01

    Barium sulfate powder used for radiopacity of experimental blood clots (EBCs) for testing mechanical thrombectomy devices (MTD) has negative effects on EBCs mechanical properties. In vitro and in vivo exploration was performed to determine if the iodine based contrast medium will have less negative effects on the EBCs than barium. Fresh blood from 2 swine was used to create fibrinogen enhanced and thrombin initiated EBC in tubes. Iodine radiopacity was achieved by mixing the blood with 65% Iohexol or by soaking the EBCs for 2 or 24 hours in Iohexol. The EBCs opacified with barium served as controls. In vitro study: The EBCs were subjected to four tests, manual elongation, catheter injection, radiopacity and contrast wash out tests. In vivo study: The common carotid arteries of 2 swine were embolized by either barium EBC or EBC soaked for 24 hours in Iohexol. The duration of radiopacity of the different EBCs was compared. The EBCs opacified with Iohexol initially had higher radiopacity than the barium opacified EBCs. However, their opacity rapidly decreased with saline soaking and, particularly, after they were embolized in live animals. The mechanical properties of Iohexol opacified EBCs were inferior to barium opacified EBCs. The Iohexol mixed EBCs were less firm and elastic and half of them fragmented during catheter injection. The Iohexol soaked EBCs exhibited decreased tensile strength and elasticity compared to the barium EBCs. Compared to barium, iodine based contrast medium does not offer any advantage for opacifying EBCs

  12. Zakharov equations for viscous flow and their use in the blood clot ...

    Indian Academy of Sciences (India)

    Ai-Ping Zhou

    2017-11-14

    Nov 14, 2017 ... This would lead to the formation of blood clot. The viscous force can suppress the occurrence of instability and prevent thrombosis. One can find that the chaotic state of blood signals human health. Keywords. Blood plasma; Zakharov equations; viscosity; modulation instability. PACS Nos 52.27.–h; 52.35.

  13. An alternate method for DNA and RNA extraction from clotted blood.

    Science.gov (United States)

    Zakaria, Z; Umi, S H; Mokhtar, S S; Mokhtar, U; Zaiharina, M Z; Aziz, A T A; Hoh, B P

    2013-02-04

    We developed an alternative method to extract DNA and RNA from clotted blood for genomic and molecular investigations. A combination of the TRIzol method and the QIAamp spin column were used to extract RNA from frozen clotted blood. Clotted blood was sonicated and then the QIAamp DNA Blood Mini Kit was used for DNA extraction. Extracted DNA and RNA were adequate for gene expression analysis and copy number variation (CNV) genotyping, respectively. The purity of the extracted RNA and DNA was in the range of 1.8-2.0, determined by absorbance ratios of A(260):A(280). Good DNA and RNA integrity were confirmed using gel electrophoresis and automated electrophoresis. The extracted DNA was suitable for qPCR and microarrays for CNV genotyping, while the extracted RNA was adequate for gene analysis using RT-qPCR.

  14. Zakharov equations for viscous flow and their use in the blood clot ...

    Indian Academy of Sciences (India)

    ... out that the imaginary part of one root of the perturbation frequency is greater than zero, and modulation instability occurs. This would lead to the formation of blood clot. The viscous force can suppress the occurrence of instability and prevent thrombosis. One can find that the chaotic state of blood signals human health.

  15. Honey Bee Venom (Apis mellifera Contains Anticoagulation Factors and Increases the Blood-clotting Time

    Directory of Open Access Journals (Sweden)

    Hossein Zolfagharian

    2015-12-01

    Full Text Available Objectives: Bee venom (BV is a complex mixture of proteins and contains proteins such as phospholipase and melittin, which have an effect on blood clotting and blood clots. The mechanism of action of honey bee venom (HBV, Apis mellifera on human plasma proteins and its anti-thrombotic effect were studied. The purpose of this study was to investigate the anti-coagulation effect of BV and its effects on blood coagulation and purification. Methods: Crude venom obtained from Apis mellifera was selected. The anti-coagulation factor of the crude venom from this species was purified by using gel filtration chromatography (sephadex G-50, and the molecular weights of the anti-coagulants in this venom estimated by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. Blood samples were obtained from 10 rabbits, and the prothrombin time (PT and the partial thromboplastin time (PTT tests were conducted. The approximate lethal dose (LD values of BV were determined. Results: Crude BV increased the blood clotting time. For BV concentrations from 1 to 4 mg/mL, clotting was not observed even at more than 300 seconds, standard deviations (SDs = ± 0.71; however, clotting was observed in the control group 13.8 s, SDs = ± 0.52. Thus, BV can be considered as containing anti-coagulation factors. Crude BV is composed 4 protein bands with molecular weights of 3, 15, 20 and 41 kilodalton (kDa, respectively. The LD50 of the crude BV was found to be 177.8 μg/mouse. Conclusion: BV contains anti-coagulation factors. The fraction extracted from the Iranian bees contains proteins that are similar to anti-coagulation proteins, such as phospholipase A2 (PLA2 and melittin, and that can increase the blood clotting times in vitro.

  16. Pre-analytical variation in glucose concentration due to atmospheric temperature and clot in blood specimens

    International Nuclear Information System (INIS)

    Butt, T.; Masud, K.; Khan, J.A.; Bhatti, M.S.

    2016-01-01

    Objective: To determine the effect of temperature and contact of clot with serum on laboratory results of glucose concentration in blood. Study Design: Quasi-experimental study. Place and Duration of Study: December 2014 to August 2015 at the laboratory of Shoaib Hospital, Fateh Jang, Attock Pakistan. Material and Methods: Samples were collected for estimation of blood glucose (Random) concentration from patients reporting to the hospital. Blood specimens (n=94) of such volunteers were analyzed for glucose level. Each sample was put up in five tubes. When the blood clotted the serum from tube-1 was analyzed for glucose level within 30 minutes. In tube-2 and tube-3 serum was kept for 24 hours at room temperature and refrigerator temperature respectively before glucose estimation. In tube-4 and tube-5 serum was not separated from clot and kept at room temperature and refrigerator temperature respectively before glucose estimation. The value of tube 1 was taken as reference value for comparison with other parts of the specimen. The equipment used for blood glucose level estimation was semi auto chemistry analyzer (Rayto, China). The kit used for analysis was Glucose - Liquizyme (Germany). Results: The difference between the mean reference value (tube-1) and refrigerated serum without clot (tube-3) was 4.63 mg/100 ml while that of unrefrigerated portion (tube-2) had a difference of 10.68 mg/100 ml. The mean of unrefrigerated (tube-4) and refrigerated (tube-5) portions of serum kept with the clot had difference of 42.05 mg/100 ml and 25.84 mg/100 ml respectively. The fall in the blood glucose level in all (n=94) the samples in the tube number 3 (serum separated and kept at refrigerated temperature) was 4.63 mg/100 ml +- 3.68 (Mean +- SD) and it ranged from 0 to 20 mg/100 ml whereas fall was maximum in the tube number 4 (serum with clotted blood and kept at room temperature) was 42.04 mg/100 ml +- 10.61 (Mean +- SD) and it ranged from 13 to 82 mg/100 ml. The sample in

  17. High-Quality and -Quantity DNA Extraction from Frozen Archival Blood Clots for Genotyping of Single-Nucleotide Polymorphisms

    DEFF Research Database (Denmark)

    Bank, Steffen; Nexø, Bjørn Andersen; Andersen, Vibeke

    2013-01-01

    Background: The recovery of biological samples for genetic epidemiological studies can be cumbersome. Blood clots are routinely collected for serological examinations. However, the extraction of DNA from blood clots can be difficult and often results in low yields. Aim: The aim was to compare the...

  18. Dimensional evaluation of blood clot gap distances within the intrabony defects following grafting and EDTA root surface treatment - experimental study in dogs.

    Science.gov (United States)

    Gamal, Ahmed Y; Abdel-Ghaffar, Khaled A; Zouair, Mohamed G; Salama, Mohamed H; Destawy, Mahmoud T El

    2018-03-14

    Since it is important to establish and maintain a firm blood clot to the surrounding tissues within the intrabony lesion; we have to investigate the potentials of different materials in resisting clot retraction that disrupt clot adhesion to the root surface. This study was designed to measure the gap distance created by clot retraction within the defect following intrabony defects grafting with and without root surface EDTA etching. Eight mongrel dogs with surgically created acute-chronic bilateral mandibular interproximal intrabony defects in the premolar-molar areas were enrolled in this study (total 8 defects per dog). Intrabony defects were divided into four groups, the first group (OFD): control open flap debridement, the second group, (EDTA treated defects) in which debridement of the defects was followed by two minute root surface etching with a neutral 24% EDTA gel followed by two minute copious saline irrigation, the third group (only grafted defects): defects received closely packed β-TCP of a particle size ranged from 150 to 500 mm, and the fourth group, (Graft + EDTA treated defects): defects were etched for 2 minutes with a neutral 24% EDTA gel and saline irrigation followed by intrabony defect fill of β-TCP. Twenty four hours post treatment, animal euthanasia was carried out for histomorphometric analysis of the tooth and root side gap distances. EDTA treated group and EDTA + graft group showed statistically significant lower degree of clot shrinkage compared to both the control and only grafted group. Clot shrinkage in EDTA treated group showed no significant difference from that of the EDTA + graft group (p = 0.197). OFD and only grafted groups were found to show statistically higher clot retraction percnetage compared to both EDTA and EDTA+graft groups. following intrabony defect debridement, blood clot undergoes clot retraction creating a micro gap with the root surface. EDTA root surface etching before graft application into the defect area

  19. Zeolite-based hemostat QuikClot releases calcium into blood and promotes blood coagulation in vitro.

    Science.gov (United States)

    Li, Jing; Cao, Wei; Lv, Xiao-xing; Jiang, Li; Li, Yue-jun; Li, Wang-zhou; Chen, Shao-zong; Li, Xue-yong

    2013-03-01

    To examine the changes in electrolyte concentrations after addition of zeolite-based hemostat QuikClot in blood and the effects of zeolite on blood coagulation in vitro. Fresh blood was taken from healthy adult volunteers and sheep, and the electrolyte concentrations in blood were measured using a blood electrolyte analyzer. Zeolite Saline Solution (ZSS) was prepared by addition of 2 g zeolite to 0.9% NaCl solution (4, 8, or 16 mL). The electrolytes in ZSS were measured using inductively coupled plasma atomic emission spectroscopy. The prothrombin time (PT) and activated partial thromboplastin time (APTT) of blood were measured using the test tube method. The activated clotting time (ACT) and clotting rate (CR) of blood were measured with Sonoclot Coagulation and Platelet Function Analyzer. Addition of zeolite (50 and 100 mg) in 2 mL human blood significantly increased Ca(2+) concentration, while Na(+) and K(+) concentrations were significantly decreased. Addition of zeolite (50 and 100 mg) in 0.9% NaCl solution (2 mL) caused similar changes in Ca(2+) and Na(+) concentrations. Si(4+) (0.2434 g/L) and Al(3+) (0.2575 g/L) were detected in ZSS (2 g/8 mL). Addition of ZSS in sheep blood shortened APTT in a concentration dependent manner, without changing PT. ZSS or aqueous solution of CaCl2 that contained Ca(2+) concentration identical to that of ZSS significantly shortened ACT in human blood without significantly changing CR, and the effect of ZSS on ACT was not significantly different from that of CaCl2. Zeolite releases Ca(2+) into blood, thus accelerating the intrinsic pathway of blood coagulation and shortening the clot formation time.

  20. Zakharov equations for viscous flow and their use in the blood clot formation

    Science.gov (United States)

    Zhou, Ai-Ping; Li, Xiao-Qing

    2017-12-01

    For theoretical study, blood can be regarded as a viscous electrically conducting fluid of negative ions and protons. Zakharov equations including viscosity are relevant for describing the behaviour of blood plasma. The dispersion formula is derived from the perturbation method and is solved numerically. It turns out that the imaginary part of one root of the perturbation frequency is greater than zero, and modulation instability occurs. This would lead to the formation of blood clot. The viscous force can suppress the occurrence of instability and prevent thrombosis. One can find that the chaotic state of blood signals human health.

  1. RESULTS OF QUALITY COMPREHENSIVE EVALUATION OF DENTAL CARE FOR CHILDREN WITH BLOOD CLOTTING (PATHOLOGY

    Directory of Open Access Journals (Sweden)

    M. A. Gavrilenko

    2014-04-01

    Full Text Available Background. Treatment methods for diseases of teeth hard tissues and periodontium for children with blood clotting pathology are described in modern literature. But in practice we are faced with the problem of providing dental treatment for these children. Work of pediatric dentist is prevented by the risk of bleeding, fear of dental procedures, child’s psychoemotional tension and refusal of treatment because of bleeding. Taking into account the specificity of blood clotting pathology, surgical methods of dental treatment prevail for these children, which is evidenced by the early loss of deciduous and permanent teeth, occlusal surface disturbances, dentoalveolar anomalies, inflammatory diseases of periodontal tissues. Aim. To evaluate the level of dental care for children with the diseases of blood clotting. Materials and methods. 120 children between 2 and 18 years old with blood clotting disorders (hemophilia A, B, thrombocytopenia, thrombocytopathy were examined. Children were divided into groups: I group – 2-5 years old (40 children, II group – 6-10 years old (40 children, III group – 11-18 years old (40 children, according to the periods of tooth development, with an equal number of children in groups according to diagnoses. Clinical examination was carried out according to the standard scheme, including the analysis of complaints, anamnesis of treatment at the dentist, objective data with the use of statistical method of masticatory efficiency (according to N.I. Agapov, the level of dental care (according to P.A. Leus. Results. During clinical dental examination of children with blood clotting pathology it was found that destruction of crowns of maxillary front teeth, the first deciduous molars and the second deciduous molars, as well as their loss, prevails in the temporary occlusion. During the examination of 2-5 years old children with blood clotting pathology, loss of less than 25% of masticatory efficiency was revealed for 25

  2. Kinetics and mechanics of clot contraction are governed by the molecular and cellular composition of the blood.

    Science.gov (United States)

    Tutwiler, Valerie; Litvinov, Rustem I; Lozhkin, Andrey P; Peshkova, Alina D; Lebedeva, Tatiana; Ataullakhanov, Fazoil I; Spiller, Kara L; Cines, Douglas B; Weisel, John W

    2016-01-07

    Platelet-driven blood clot contraction (retraction) is thought to promote wound closure and secure hemostasis while preventing vascular occlusion. Notwithstanding its importance, clot contraction remains a poorly understood process, partially because of the lack of methodology to quantify its dynamics and requirements. We used a novel automated optical analyzer to continuously track in vitro changes in the size of contracting clots in whole blood and in variously reconstituted samples. Kinetics of contraction was complemented with dynamic rheometry to characterize the viscoelasticity of contracting clots. This combined approach enabled investigation of the coordinated mechanistic impact of platelets, including nonmuscle myosin II, red blood cells (RBCs), fibrin(ogen), factor XIIIa (FXIIIa), and thrombin on the kinetics and mechanics of the contraction process. Clot contraction is composed of 3 sequential phases, each characterized by a distinct rate constant. Thrombin, Ca(2+), the integrin αIIbβ3, myosin IIa, FXIIIa cross-linking, and platelet count all promote 1 or more phases of the clot contraction process. In contrast, RBCs impair contraction and reduce elasticity, while increasing the overall contractile stress generated by the platelet-fibrin meshwork. A better understanding of the mechanisms by which blood cells, fibrin(ogen), and platelet-fibrin interactions modulate clot contraction may generate novel approaches to reveal and to manage thrombosis and hemostatic disorders. © 2016 by The American Society of Hematology.

  3. Phase transitions during compression and decompression of clots from platelet-poor plasma, platelet-rich plasma and whole blood.

    Science.gov (United States)

    Liang, Xiaojun; Chernysh, Irina; Purohit, Prashant K; Weisel, John W

    2017-09-15

    Blood clots are required to stem bleeding and are subject to a variety of stresses, but they can also block blood vessels and cause heart attacks and ischemic strokes. We measured the compressive response of human platelet-poor plasma (PPP) clots, platelet-rich plasma (PRP) clots and whole blood clots and correlated these measurements with confocal and scanning electron microscopy to track changes in clot structure. Stress-strain curves revealed four characteristic regions, for compression-decompression: (1) linear elastic region; (2) upper plateau or softening region; (3) non-linear elastic region or re-stretching of the network; (4) lower plateau in which dissociation of some newly made connections occurs. Our experiments revealed that compression proceeds by the passage of a phase boundary through the clot separating rarefied and densified phases. This observation motivates a model of fibrin mechanics based on the continuum theory of phase transitions, which accounts for the pre-stress caused by platelets, the adhesion of fibrin fibers in the densified phase, the compression of red blood cells (RBCs), and the pumping of liquids through the clot during compression/decompression. Our experiments and theory provide insights into the mechanical behavior of blood clots that could have implications clinically and in the design of fibrin-based biomaterials. The objective of this paper is to measure and mathematically model the compression behavior of various human blood clots. We show by a combination of confocal and scanning electron microscopy that compression proceeds by the passage of a front through the sample that separates a densified region of the clot from a rarefied region, and that the compression/decompression response is reversible with hysteresis. These observations form the basis of a model for the compression response of clots based on the continuum theory of phase transitions. Our studies may reveal how clot rheology under large compression in vivo due

  4. Addition of a sequence from α2-antiplasmin transforms human serum albumin into a blood clot component that speeds clot lysis

    Directory of Open Access Journals (Sweden)

    Gataiance Sharon

    2009-03-01

    Full Text Available Abstract Background The plasma protein α2-antiplasmin (α2AP is cross-linked to fibrin in blood clots by the transglutaminase factor XIIIa, and in that location retards clot lysis. Competition for this effect could be clinically useful in patients with thrombosis. We hypothesized that fusion of N-terminal portions of α2-antiplasmin to human serum albumin (HSA and production of the chimeric proteins in Pichia pastoris yeast would produce a stable and effective competitor protein. Results Fusion protein α2AP(13-42-HSA was efficiently secreted from transformed yeast and purified preparations contained within a mixed population the full-length intact form, while fusions with longer α2AP moieties were inefficiently secreted and/or degraded. The α2AP(13-42-HSA protein, but not recombinant HSA, was cross-linked to both chemical lysine donors and fibrin or fibrinogen by factor XIIIa, although with less rapid kinetics than native α2AP. Excess α2AP(13-42-HSA competed with α2AP for cross-linking to chemical lysine donors more effectively than a synthetic α2AP(13-42 peptide, and reduced the α2AP-dependent resistance to fibrinolysis of plasma clots equally effectively as the peptide. Native α2AP was found in in vivo clots in rabbits to a greater extent than α2AP(13-42, however. Conclusion In this first report of transfer of transglutamination substrate status from one plasma protein to another, fusion protein α2AP(13-42-HSA was shown to satisfy initial requirements for a long-lasting, well-tolerated competitive inhibitor of α2-antiplasmin predicted to act in a clot-localized manner.

  5. Abolished ventilation and perfusion of lung caused by blood clot in the left main bronchus

    DEFF Research Database (Denmark)

    Afzelius, P; Bergmann, A; Henriksen, J H

    2015-01-01

    /Q) scintigraphy with single-photon emission CT (SPECT)/CT. V/Q SPECT/CT demonstrated abolished ventilation due to obstruction of the left main bronchus and markedly reduced perfusion of the entire left lung, a condition that was completely reversed after removal of a blood clot. We present the first pictorially......It is generally assumed that the lungs possess arterial autoregulation associated with bronchial obstruction. A patient with pneumonia and congestive heart failure unexpectedly developed frequent haemoptysis. High-resolution CT and diagnostic CT were performed as well as ventilation/perfusion (V...

  6. A portable blood plasma clot micro-elastometry device based on resonant acoustic spectroscopy.

    Science.gov (United States)

    Krebs, C R; Li, Ling; Wolberg, Alisa S; Oldenburg, Amy L

    2015-07-01

    Abnormal blood clot stiffness is an important indicator of coagulation disorders arising from a variety of cardiovascular diseases and drug treatments. Here, we present a portable instrument for elastometry of microliter volume blood samples based upon the principle of resonant acoustic spectroscopy, where a sample of well-defined dimensions exhibits a fundamental longitudinal resonance mode proportional to the square root of the Young's modulus. In contrast to commercial thromboelastography, the resonant acoustic method offers improved repeatability and accuracy due to the high signal-to-noise ratio of the resonant vibration. We review the measurement principles and the design of a magnetically actuated microbead force transducer applying between 23 pN and 6.7 nN, providing a wide dynamic range of elastic moduli (3 Pa-27 kPa) appropriate for measurement of clot elastic modulus (CEM). An automated and portable device, the CEMport, is introduced and implemented using a 2 nm resolution displacement sensor with demonstrated accuracy and precision of 3% and 2%, respectively, of CEM in biogels. Importantly, the small strains (<0.13%) and low strain rates (<1/s) employed by the CEMport maintain a linear stress-to-strain relationship which provides a perturbative measurement of the Young's modulus. Measurements of blood plasma CEM versus heparin concentration show that CEMport is sensitive to heparin levels below 0.050 U/ml, which suggests future applications in sensing heparin levels of post-surgical cardiopulmonary bypass patients. The portability, high accuracy, and high precision of this device enable new clinical and animal studies for associating CEM with blood coagulation disorders, potentially leading to improved diagnostics and therapeutic monitoring.

  7. Changes to the structure of blood clots formed in the presence of fine particulate matter

    International Nuclear Information System (INIS)

    Metassan, Sofian; Routledge, Michael N; Ariens, Robert A S; Scott, D Julian

    2009-01-01

    Both long-term and short-term exposure (one to two hours) to particulate matter are associated with morbidity and mortality caused by cardiovascular diseases. The underlying mechanisms leading to cardiovascular events are unclear, however, changes to blood coagulability upon exposure to ultrafine particulate matter (UFPM, the smallest of which can enter the circulation) is a plausible mechanism. Objectives: This study aims to investigate the direct effects of particulate matter on fibrin polymerization, lateral aggregation and the formation of fibrin network structure. Methods: Standard Urban Particulate Matter (PM) was suspended in Tris buffer centrifuged and filtered with <200nm filter to obtain ultrafine PM or their water-soluble components. Purified normal fibrinogen was made to clot by adding thrombin and calcium chloride in the presence of varying concentrations of PM. Permeation properties (Darcy constant [Ks]) and turbidity of clots were measured to investigate the effects on flow-rate, pore size, and fibrin polymerization. In addition, confocal microscopy was performed to study detailed clot structure. Results: Total PM increased the Ks of clots in a dose dependant manner (Ks = 4.4, 6.9 and 13.2 x 10-9 cm2 for 0, 50 and 100 |ag/ml total PM concentrations, respectively). Filtered PM also produced a significant increase in Ks at PM concentration of 17 |ag/ml. Final turbidity measurements at 20min were obtained for varying concentrations of PM. Maximum optical density (OD) for 1 mg/ml fibrinogen at 0, 50, 100 and 200 |ag/ml total PM concentrations were 0.39, 0.42, 0.45 and 0.46, respectively. The maximum OD for 0, 17, 34 and 68 |ag/ml filtered PM concentrations were 0.39, 0.42 0.47 and 0.51, respectively, suggesting an increase in fibre diameter with increasing particulate concentration. The lag phase was significantly shorter and the rate of polymerisation was significantly faster in the presence of 68 |ag/ml filtered PM. Confocal microscopy results showed

  8. Effect of anticoagulant administration on blood clotting and some hormones related to rat-fertility

    International Nuclear Information System (INIS)

    Abdel-Khalek, L.G.

    2009-01-01

    This study was performed using 30 mature male albino rats divided into 3 equal groups; control and two treated groups to assess the effect of anticoagulant (warfarin) administration on the level of some hormones related to fertility. The two treated groups were injected intraperitoneally every other day with 1 ml (0.03 mg)and 2 ml (0.06 mg)warfarin/ 100 g body weight respectively where, two specimens were taken from each group after two and four weeks. Clotting time (CT), prothrombin time (PT), partial prothrombin time (PTT) platelets count, fasting blood sugar (F.B.S), calcium levels in addition to triiodothyronine (T 3 ), thyroxin (T 4 ), insulin, corticosterone, and testosterone hormones were determined. The results showed that the intraperitoneal injection of warfarin caused significant increase in clotting time, prothrombin time , partial prothrombin time, platelets count and glucose level, while serum calcium level showed significant decrease. Intraperitoneal injection of warfarin caused significant decrease of insulin and significant increase of corticosterone, T 3 showed significant decrease in high dose group while T 4 showed significant decrease in small dose group. The high dose was associated with the highest level of testosterone hormone. these results denoted that warfarin anticoagulant had no negative effect on gonadal sex hormone and hence on male fertility

  9. Thrombin generation and fibrin clot formation under hypothermic conditions: an in vitro evaluation of tissue factor initiated whole blood coagulation.

    Science.gov (United States)

    Whelihan, Matthew F; Kiankhooy, Armin; Brummel-Ziedins, Kathleen E

    2014-02-01

    Despite trauma-induced hypothermic coagulopathy being familiar in the clinical setting, empirical experimentation concerning this phenomenon is lacking. In this study, we investigated the effects of hypothermia on thrombin generation, clot formation, and global hemostatic functions in an in vitro environment using a whole blood model and thromboelastography, which can recapitulate hypothermia. Blood was collected from healthy individuals through venipuncture and treated with corn trypsin inhibitor, to block the contact pathway. Coagulation was initiated with 5pM tissue factor at temperatures 37°C, 32°C, and 27°C. Reactions were quenched over time, with soluble and insoluble components analyzed for thrombin generation, fibrinogen consumption, factor (f)XIII activation, and fibrin deposition. Global coagulation potential was evaluated through thromboelastography. Data showed that thrombin generation in samples at 37°C and 32°C had comparable rates, whereas 27°C had a much lower rate (39.2 ± 1.1 and 43 ± 2.4 nM/min vs 28.6 ± 4.4 nM/min, respectively). Fibrinogen consumption and fXIII activation were highest at 37°C, followed by 32°C and 27°C. Fibrin formation as seen through clot weights also followed this trend. Thromboelastography data showed that clot formation was fastest in samples at 37°C and lowest at 27°C. Maximum clot strength was similar for each temperature. Also, percent lysis of clots was highest at 37°C followed by 32°C and then 27°C. Induced hypothermic conditions directly affect the rate of thrombin generation and clot formation, whereas global clot stability remains intact. © 2013.

  10. Intracameral air injection during Ahmed glaucoma valve implantation in neovascular glaucoma for the prevention of tube obstruction with blood clot: Case Report.

    Science.gov (United States)

    Hwang, Sung Ha; Yoo, Chungkwon; Kim, Yong Yeon; Lee, Dae Young; Nam, Dong Heun; Lee, Jong Yeon

    2017-12-01

    Glaucoma drainage implant surgery is a treatment option for the management of neovascular glaucoma. However, tube obstruction by blood clot after Ahmed glaucoma valve (AGV) implantation is an unpredictable clinically challenging situation. We report 4 cases using intracameral air injection for the prevention of the tube obstruction of AGV by blood clot. The first case was a 57-year-old female suffering from ocular pain because of a tube obstruction with blood clot after AGV implantation in neovascular glaucoma. Surgical blood clot removal was performed. However, intractable bleeding was noted during the removal of the blood clot, and so intracameral air injection was performed to prevent a recurrent tube obstruction. After the procedure, although blood clots formed around the tube, the tube opening where air could touch remained patent. In 3 cases of neovascular glaucoma with preoperative severe intraocular hemorrhages, intracameral air injection and AGV implantation were performed simultaneously. In all 3 cases, tube openings were patent. It appears that air impeded the blood clots formation in front of the tube opening. Intracameral air injection could be a feasible option to prevent tube obstruction of AGV implant with a blood clot in neovascular glaucoma with high risk of tube obstruction. Copyright © 2017 The Authors. Published by Wolters Kluwer Health, Inc. All rights reserved.

  11. Highly Effective DNA Extraction Method from Fresh, Frozen, Dried and Clotted Blood Samples

    Directory of Open Access Journals (Sweden)

    Jaleh Barar

    2011-09-01

    Full Text Available Introduction: Today, with the tremendous potential of genomics and other recent advances in science, the role of science to improve reliable DNA extraction methods is more relevant than ever before. The ideal process for genomic DNA extraction demands high quantities of pure, integral and intact genomic DNA (gDNA from the sample with minimal co-extraction of inhibitors of downstream processes. Here, we report the development of a very rapid, less-hazardous, and high throughput protocol for extracting of high quality DNA from blood samples. Methods: Dried, clotted and ethylene diamine tetra-acetic acid (EDTA treated fresh and frozen blood samples were extracted using this method in which the quality and integrity of the extracted DNA were corroborated by agarose gel electrophoresis, PCR reaction and DNA digestion using restricted enzyme. The UV spectrophotometric and gel electrophoresis analysis resulted in high A260/A280 ratio (>1.8 with high intactness of DNA. Results: PCR and DNA digestion experiments indicated that the final solutions of extracted DNA contained no inhibitory substances, which confirms that the isolated DNA is of good quality. Conclusion: The high quality and quantity of current method, no enzymatic processing and accordingly its low cost, make it appropriate for DNA extraction not only from human but also from animal blood samples in any molecular biology labs.

  12. Cloning, expression and characterization of a gene from earthworm Eisenia fetida encoding a blood-clot dissolving protein.

    Directory of Open Access Journals (Sweden)

    GangQiang Li

    Full Text Available A lumbrokinase gene encoding a blood-clot dissolving protein was cloned from earthworm (Eisenia fetida by RT-PCR amplification. The gene designated as CST1 (GenBank No. AY840996 was sequence analyzed. The cDNA consists of 888 bp with an open reading frame of 729 bp, which encodes 242 amino acid residues. Multiple sequence alignments revealed that CST1 shares similarities and conserved amino acids with other reported lumbrokinases. The amino acid sequence of CST1 exhibits structural features similar to those found in other serine proteases, including human tissue-type (tPA, urokinase (uPA, and vampire bat (DSPAα1 plasminogen activators. CST1 has a conserved catalytic triad, found in the active sites of protease enzymes, which are important residues involved in polypeptide catalysis. CST1 was expressed as inclusion bodies in Escherichia coli BL21(DE3. The molecular mass of recombinant CST1 (rCST was 25 kDa as estimated by SDS-PAGE, and further confirmed by Western Blot analysis. His-tagged rCST1 was purified and renatured using nickel-chelating resin with a recovery rate of 50% and a purity of 95%. The purified, renatured rCST1 showed fibrinolytic activity evaluated by both a fibrin plate and a blood clot lysis assay. rCST1 degraded fibrin on the fibrin plate. A significant percentage (65.7% of blood clot lysis was observed when blood clot was treated with 80 mg/mL of rCST1 in vitro. The antithrombotic activity of rCST1 was 912 units/mg calculated by comparison with the activity of a lumbrokinase standard. These findings indicate that rCST1 has potential as a potent blood-clot treatment. Therefore, the expression and purification of a single lumbrokinase represents an important improvement in the use of lumbrokinases.

  13. Prostatic Fossa Gauze-Packing in the Prevention of Blood Clot ...

    African Journals Online (AJOL)

    BACKGROUND: Clot obstruction often complicates transvesical prostatectomy. Any measure that prevents this will be a great relief to both surgeon and patient. OBJECTIVE: To demonstrate that packing the prostatic fossa with roller gauze bandage after transvesical prostatectomy can prevent post-operative clot blockage of ...

  14. A targeted ferritin-microplasmin based thrombolytic nanocage selectively dissolves blood clots.

    Science.gov (United States)

    Seo, Junyoung; Al-Hilal, Taslim A; Jee, Jun-Goo; Kim, Yong-Lim; Kim, Ha-Jeong; Lee, Byung-Heon; Kim, Soyoun; Kim, In-San

    2018-04-01

    The use of thrombolytic therapies is limited by an increased risk of systemic hemorrhage due to lysis of hemostatic clots. We sought to develop a plasmin-based thrombolytic nanocage that efficiently dissolves the clot without causing systemic fibrinolysis or disrupting hemostatic clots. Here, we generated a double chambered short-length ferritin (sFt) construct that has an N-terminal region fused to multivalent clot targeting peptides (CLT: CNAGESSKNC) and a C-terminal end fused to a microplasmin (μPn); CLT recognizes fibrin-fibronectin complexes in clots, μPn efficiently dissolves clots, and the assembly of double chambered sFt (CLT-sFt-μPn) into nanocage structure protects the activated-μPn from its circulating inhibitors. Importantly, activated CLT-sFt-μPn thrombolytic nanocage showed a prolonged circulatory life over activated-μPn and efficiently lysed the preexisting clots in both arterial and venous thromboses models. Thus, CLT-sFt-μPn thrombolytic nanocage platform represents the prototype of a targeted clot-busting agent with high efficacy and safety over existing thrombolytic therapies. Copyright © 2018 Elsevier Inc. All rights reserved.

  15. Does prior administration of enoxaparin influence the effects of levobupivacaine on blood clotting? Assessment using the Thrombelastograph.

    LENUS (Irish Health Repository)

    Leonard, S A

    2012-02-03

    The low molecular weight heparin, enoxaparin (by inhibition of factors Xa and IIa) and amide local anaesthetics (by altering platelet function) exert anti-clotting effects. Although these agents are often used in combination during the perioperative period, their potential interactive effect on clotting has not been defined. Blood from 10 ASA I-II patients who received enoxaparin 0.5 mg kg(-1) s.c. was studied using a Thrombelastograph (TEG) either alone or in combination with levobupivacaine (2.5 mg ml(-1) or 2.5 microg ml(-1)) or saline (50% dilution). In blood from patients who had received enoxaparin 0.5 mg kg(-1) s.c. 12 h previously, levobupivacaine 2.5 mg ml(-1) (but not 2.5 microg ml(-1)) produced significant changes in TEG clotting parameters (mean (SD) 15.7 (4.8) mm, 29.6 (25.6) mm, 34.4 (14.6) mm, 34.3 (12.2) degrees compared with control values of 6.1 (1.3) mm, 2.5 (0.5) mm, 63.5 (6.4) mm and 74.1 (2.9) degrees for r, K, MA, and alpha angle respectively).

  16. Investigation of the effect of kaolin and tissue factor-activated citrated whole blood, on clot forming variables, as evaluated by thromboelastograph

    DEFF Research Database (Denmark)

    Johansson, Per Ingemar; Bochsen, L.; Andersen, S.

    2008-01-01

    BACKGROUND: The Thrombelastograph (TEG; Haemoscope Corp.) analyzes clot formation in whole blood (WB) and treatment based on this analysis has been shown to reduce transfusion requirements in liver and cardiac surgery when compared to conventional coagulation analysis. Implementing TEG as a routine...... laboratory-based analysis, however, requires validation of the activators employed and the effect of storage of the WB sample in citrate before analysis. STUDY DESIGN AND METHODS: The effect of kaolin, tissue factor (TF) 1:17,000, or TF 1:42,500 on TEG clotting time (R), Angle (velocity of clot formation......), and maximum clot strength (amplitude [MA]) were evaluated, together with day-to-day variation, the coefficient of variance (CV%), and the effect of citrate storage time. RESULTS: Clot formation variables were equally affected by TF 1:17,000 and kaolin activation, whereas R was significantly longer when TF 1...

  17. Fibrinolytic Activity and Dose-Dependent Effect of Incubating Human Blood Clots in Caffeic Acid Phenethyl Ester: In Vitro Assays

    Directory of Open Access Journals (Sweden)

    Abuzar Elnager

    2015-01-01

    Full Text Available Background. Caffeic acid phenethyl ester (CAPE has been reported to possess time-dependent fibrinolytic activity by in vitro assay. This study is aimed at investigating fibrinolytic dose-dependent activity of CAPE using in vitro assays. Methods. Standardized human whole blood (WB clots were incubated in either blank controls or different concentrations of CAPE (3.75, 7.50, 15.00, 22.50, and 30.00 mM. After 3 hours, D-dimer (DD levels and WB clot weights were measured for each concentration. Thromboelastography (TEG parameters were recorded following CAPE incubation, and fibrin morphology was examined under a confocal microscope. Results. Overall, mean DD (μg/mL levels were significantly different across samples incubated with different CAPE concentrations, and the median pre- and postincubation WB clot weights (grams were significantly decreased for each CAPE concentration. Fibrin removal was observed microscopically and indicated dose-dependent effects. Based on the TEG test, the Ly30 fibrinolytic parameter was significantly different between samples incubated with two different CAPE concentrations (15.0 and 22.50 mM. The 50% effective dose (ED50 of CAPE (based on DD was 1.99 mg/mL. Conclusions. This study suggests that CAPE possesses fibrinolytic activity following in vitro incubation and that it has dose-dependent activities. Therefore, further investigation into CAPE as a potential alternative thrombolytic agent should be conducted.

  18. Response of the blood clotting system of the American horseshoe crab, Limulus polyphemus, to a novel form of lipopolysaccharide from a green alga.

    Science.gov (United States)

    Conrad, Mara L; Pardy, R L; Wainwright, Norman; Child, Alice; Armstrong, Peter B

    2006-08-01

    Lipopolysaccharide (LPS, endotoxin) is a component of Gram-negative bacteria and is the principal indicator to the innate immune systems of higher animals of a Gram-negative bacterial invasion. LPS activates the blood clotting system of the American horseshoe crab, Limulus polyphemus. By stimulating blood cell degranulation, LPS triggers the release of the proteins of the clotting system from the cells, and by activating a protease cascade that converts coagulogen, a soluble zymogen, to coagulin, the structural protein of the clot, LPS triggers the production of the fibrillar coagulin blood clot. Although originally thought to be restricted to the Gram-negative bacteria and the cyanobacteria, LPS, or a very similar molecule, has recently been described from a eukaryotic green alga, Chlorella. Here we show that, like LPS from Gram-negative bacteria, the algal molecule stimulates exocytosis of the Limulus blood cell and the clotting of coagulin. The coagulin clot efficiently entraps the cells of Chlorella in a network of fibrils. Invasion and erosion of the carapace by green algae is an important cause of mortality of Limulus, and it is suggested that the cellular response to aLPS may contribute to defense against this pathogen.

  19. Heat transfer analysis on peristaltically induced motion of particle-fluid suspension with variable viscosity: Clot blood model.

    Science.gov (United States)

    Bhatti, M M; Zeeshan, A; Ellahi, R

    2016-12-01

    In this article, heat transfer analysis on clot blood model of the particle-fluid suspension through a non-uniform annulus has been investigated. The blood propagating along the whole length of the annulus was induced by peristaltic motion. The effects of variable viscosity and slip condition are also taken into account. The governing flow problem is modeled using lubrication approach by taking the assumption of long wavelength and creeping flow regime. The resulting equation for fluid phase and particle phase is solved analytically and closed form solutions are obtained. The physical impact of all the emerging parameters is discussed mathematically and graphically. Particularly, we considered the effects of particle volume fraction, slip parameter, the maximum height of clot, viscosity parameter, average volume flow rate, Prandtl number, Eckert number and fluid parameter on temperature profile, pressure rise and friction forces for outer and inner tube. Numerical computations have been used to determine the behavior of pressure rise and friction along the whole length of the annulus. The present study is also presented for an endoscope as a special case of our study. It is observed that greater influence of clot tends to rise the pressure rise significantly. It is also found that temperature profile increases due to the enhancement in Prandtl number, Eckert number, and fluid parameter. The present study reveals that friction forces for outer tube have higher magnitude as compared to the friction forces for an inner tube. In fact, the results for present study can also be reduced to the Newtonian fluid by taking ζ → ∞. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  20. Sonorheometry assessment of platelet function in cardiopulmonary bypass patients: Correlation of blood clot stiffness with platelet integrin αIIbβ3 activity, aspirin usage, and transfusion risk.

    Science.gov (United States)

    Viola, Francesco; Lin-Schmidt, Xiefan; Bhamidipati, Castigliano; Haverstick, Doris M; Walker, William F; Ailawadi, Gorav; Lawrence, Michael B

    2016-02-01

    Impaired platelet function may underlie bleeding associated with cardiopulmonary bypass (CPB) and at present is incompletely evaluated with existing diagnostic technologies. Sonorheometry (SR) is a recently developed ultrasound-based technology that quantifies hemostasis and platelet activity from a blood sample by measuring ex vivo clot stiffness (S). We hypothesized that impaired platelet-fibrin interactions as assessed by SR would correlate with transfusion during CPB and history of prior aspirin therapy. Thirty-nine patients undergoing elective cardiopulmonary bypass (CPB) were enrolled following informed consent (University of Virginia IRB#14050) in a prospective observational pilot study to assess pre-operative platelet function and transfusion frequency. To assess platelet activity, abciximab was added to blood prior to SR and native S versus abciximab treated S created a differential test for platelet activity. Patient blood samples were activated with kaolin and SR was then used to measure clot stiffness. Patients were transfused with blood products as directed by clinical practice, with the surgical team blinded to SR results. Blood clot stiffness with and without abciximab, was compared in a ratio test (S/Sabciximab) named the Platelet Function Index (PFI). PFI was hypothesized to be positively correlated with platelet contributions through integrin αIIbβ3 to clot stiffness. PFI for CPB subjects was lower for those receiving transfusions than those not receiving transfusions (paspirin therapy was lower than for those not on aspirin therapy (paspirin effects on risk of surgical bleeding. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Zakharov equations for viscous flow and their use in the blood clot ...

    Indian Academy of Sciences (India)

    Ai-Ping Zhou

    2017-11-14

    Nov 14, 2017 ... than 200 negative charges. Therefore, the blood plasma can be considered as a viscous, electrically conducting fluid containing protons and negative ions, and the rhe- ological properties of blood have been widely studied in the past few years [1–3]. So far, many studied blood coagulation using theoret-.

  2. Zakharov equations for viscous flow and their use in the blood clot ...

    Indian Academy of Sciences (India)

    For theoretical study, blood can be regarded as a viscous electrically conducting fluid of negative ions and protons. Zakharov equations including viscosity are relevant for describing the behaviour of blood plasma. The dispersion formula is derived from the perturbation method and is solved numerically. It turns out that the ...

  3. Vibrations and spatial patterns in biomimetic surfaces: using the shark-skin effect to control blood clotting.

    Science.gov (United States)

    Ramachandran, Rahul; Maani, Nazanin; Rayz, Vitaliy L; Nosonovsky, Michael

    2016-08-06

    We study the effect of small-amplitude fast vibrations and small-amplitude spatial patterns on various systems involving wetting and liquid flow, such as superhydrophobic surfaces, membranes and flow pipes. First, we introduce a mathematical method of averaging the effect of small spatial and temporal patterns and substituting them with an effective force. Such an effective force can change the equilibrium state of a system as well as a phase state, leading to surface texture-induced and vibration-induced phase control. Vibration and patterns can effectively jam holes in vessels with liquid, separate multi-phase flow, change membrane properties, result in propulsion and locomotion and lead to many other multi-scale, nonlinear effects including the shark-skin effect. We discuss the application of such effects to blood flow for novel biomedical 'haemophobic' applications which can prevent blood clotting and thrombosis by controlling the surface pattern at a wall of a vessel (e.g. a catheter or stent).This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. © 2016 The Author(s).

  4. Anticoagulant Carryover May Influence Clot Formation in Direct Tube Coagulase Tests from Blood Cultures

    OpenAIRE

    Varettas, Kerry; Mukerjee, Chinmoy; Taylor, Peter C.

    2005-01-01

    The tube coagulase test (TCT) performed directly from positive blood culture bottles has been used to reduce the turnaround time for identifying Staphylococcus aureus. Most reports have shown the test to be specific but often lacking sufficient sensitivity to be useful. In a prospective study of blood culture bottles (BCB) signaling positive, with a Gram-stained smear showing gram-positive cocci resembling staphylococci, the sensitivity of the direct TCT was improved by diluting the BCB broth...

  5. Factors affecting the lung perfused blood volume in patients with intrapulmonary clots after anti-coagulation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Munemasa, E-mail: radokada@yamaguchi-u.ac.jp [Department of Radiology, Yamaguchi University Graduate School of Medicine 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Masuda, Yu [4th Grade of 6-year Medicine Doctor Program, Department of Medicine, Yamaguchi University Faculty of Medicine and Health Sciences 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Nakashima, Yoshiteru [Department of Radiology, Yamaguchi Grand Medical Center, Oosaki 77, Hofu, Yamaguchi 747-8511 (Japan); Nomura, Takafumi; Nakao, Sei [Department of Radiology, Yamaguchi University Graduate School of Medicine 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Suga, Kazuyoshi [Department of Radiology, St Hills Hospital, Imamurakita 3-7-18, Ube, Yamaguchi 755-0155 (Japan); Kido, Shoji [Computer-aided Diagnosis and Biomedical Imaging Research Biomedical Engineering, Applied Medical Engineering Science Graduate School of Medicine, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611 (Japan); Matsunaga, Naofumi [Department of Radiology, Yamaguchi University Graduate School of Medicine 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan)

    2015-08-15

    Highlights: • Dual-energy CT can provide morphological and functional lung images in the same examination. • The subsequent dual-energy CT demonstrates the increased whole lung perfused blood volume (V{sub 120}) despite the residual intrapulmonary clots after treatment in one examination. • The increased whole lung perfusion (V{sub 120}) and a decreased low perfusion volume (V{sub 5}) result in the improvement in the low perfusion rate (%V{sub 5}) in the patients with acute pulmonary embolism after treatment. - Abstract: Objectives: Factors affecting the improvement in the lung perfused blood volume (LPBV) were evaluated based on the presence of intrapulmonary clots (IPCs) after anti-coagulation therapy using 64-slice dual-energy CT. Materials and methods: 96 patients exhibiting venous thromboembolism underwent initial and repeated LPBV examinations between December 2008 and July 2014. Fifteen patients were excluded due to pulmonary comorbidities, and a total of 81 patients were included in this study. Acute pulmonary embolism (PE) was diagnosed in 46 of the patients (56.7%). LPBV images were three-dimensionally reconstructed with two threshold ranges: 1–120 HU (V{sub 120}) and 1–5 HU (V{sub 5}), and the relative value of V{sub 5} per V{sub 120} expressed as %V{sub 5}. These values were subsequently compared with indicators of the severity of PE, such as the D-dimer level, heart rate and CT measurements. This study was approved by the local ethics committee. Results: In patients with IPCs, the D-dimer, V{sub 5} and %V{sub 5}values were significantly larger (p ≤ 0.01) in the initial LPBV, although these differences disappeared in subsequent LPBV after treatment. The right ventricular (RV) diameter, RV/left ventricular (RV/LV) diameter ratio and %V{sub 5} values were also significantly reduced, whereas the V{sub 5} value did not significantly decrease (p = 0.07), but V{sub 120} value significantly increased (p < 0.001) after treatment. However, in

  6. Anticoagulant carryover may influence clot formation in direct tube coagulase tests from blood cultures.

    Science.gov (United States)

    Varettas, Kerry; Mukerjee, Chinmoy; Taylor, Peter C

    2005-09-01

    The tube coagulase test (TCT) performed directly from positive blood culture bottles has been used to reduce the turnaround time for identifying Staphylococcus aureus. Most reports have shown the test to be specific but often lacking sufficient sensitivity to be useful. In a prospective study of blood culture bottles (BCB) signaling positive, with a Gram-stained smear showing gram-positive cocci resembling staphylococci, the sensitivity of the direct TCT was improved by diluting the BCB broth 1:10 in saline before inoculating 0.1 ml into 1.0 ml of 10% pooled human plasma. It was hypothesized that the improved sensitivity might be explained by reduced carryover of the anticoagulant sodium polyanetholesulfonate (SPS) used in blood culture media. By titrating the inoculum size and the concentration of SPS in an in vitro checkerboard assay, it was shown that concentrations of SPS >0.0008% prevented plasma coagulation. The 1:10 dilution of blood culture broth reduced the amount of residual SPS carried over to the TCT to a level (0.0005%) that did not impair plasma coagulation. The direct TCT inoculated with a 1:10 saline dilution of blood culture broth achieved 100% specificity and sensitivity within 4 h of inoculation without reducing the quality or quantity of coagulum.

  7. an unusual cause of clotted blood in epidural catheter : case studies

    African Journals Online (AJOL)

    pharyngeal temperature probe, intra-arterial blood pressure monitoring and a central venous pressure catheter. Three hours after the commencement of surgery we failed to inject a second bolus via the epidural catheter, as marked resistance to the injection was encountered. The initial patent catheter was now.

  8. A comparative evaluation of the blood clot, platelet-rich plasma, and platelet-rich fibrin in regeneration of necrotic immature permanent teeth: A clinical study

    Directory of Open Access Journals (Sweden)

    Isha Narang

    2015-01-01

    Full Text Available Introduction: This study was designed as a clinical trial to evaluate and compare the regenerative potential of platelet-rich fibrin (PRF, platelet-rich plasma (PRP, and blood clot in immature necrotic permanent teeth with or without associated apical periodontitis. Methods: Access preparation was done under rubber dam isolation. Copious irrigation was done with 2.5% NaOCl and triple antibiotic paste was placed as an intracanal medicament. After 4 weeks, the cases were divided into four groups with five patients in each group. The study design had three test arms and one control arm. Group I in which mineral trioxide aggregate apexification was carried out and it was kept as control group to evaluate the regenerative potential of blood clot and platelet concentrates, Group II in which blood clot was used as scaffold in the canal, Group III in PRF was used as scaffold, and Group IV in which PRP carried on collagen was used as a scaffold. Results: The clinical and radiographic evaluation after 6 and 18 months was done by two independent observers who were blinded from the groups. The scoring was done as: None score was denoted by, Fair by 1, Good by 2, and Excellent by 3. The data were then analyzed statistically by Fisher′s exact test using Statistics and Data 11.1(PRP Using harvest Smart PReP2 which showed statistically significant values in Group III as compared to other Groups. Conclusion: PRF has huge potential to accelerate the growth characteristics in immature necrotic permanent teeth as compared to PRP and blood clot.

  9. Blood Clotting and Pregnancy

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  10. Blood Clotting and Pregnancy

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  8. How Blood Clots

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  3. Postpartum Blood Clots

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  6. The Effect of Radioactive Lantern Mantle Powder and Bentonite-Zeoloite Minerals on the Volume of Blood Loss, Bleeding and Clotting Time

    Directory of Open Access Journals (Sweden)

    M Atefi

    2009-04-01

    Full Text Available ABSTRACT Introduction & Objective: Over the past decade the US army has widely studied new technologies for stopping sever hemorrhages and has introduced an effective Zeolite based hemostatic agent. On the other hand, Mortazavi and his colleagues previously reported the bio-stimulatory effects of the topical application of radioactive lantern mantle powder on wound healing. Their subsequent studies showed significant changes in some histological parameters concerning healing. In this light, here the bio-stimulatory effect of burned radioactive lantern mantles powder as well as two minerals bentonite and zeolite are presented. Materials & Methods: This experimental study was conducted in the center for radiological studies, Shiraz University of Medical Sciences in 2008. Fifty male Wistar rats were divided randomly into 5 groups of 10 animals each. Following anesthesia, animals’ tails were cut at a thickness of 5 mm by using a surgical scissor. No intervention was made on the animals of the 1st group. The 2nd to 4th group received topical non-radioactive lantern mantle powder, radioactive lantern mantle powder, Bentonite mineral or a mixture of Bentonite-Zeoliteat minerals respectively. After treatment with above mentioned agents, the volume of blood loss was measured using a scaled test-tube. The bleeding time and clotting time were also measured using a chronometer. SPSS software was used for statistical analysis. ANOVA was used for comparing the means of each parameter in the 5 groups. Results: The the volume of blood loss, bleeding and clotting times in control animals were 4.39±1.92 cc, 112.10±39.60 sec and 94.9±54.26 sec, respectively. In the 5th group in which the animals were treated with a mixture of Bentonite-Zeoliteat minerals, the volume of blood loss, bleeding and clotting times were 1.31±0.60 cc, 34.50±4.65 sec and 24.2±4.61 sec, respectively. Conclusion: This is the 1st investigation that studied the alterations of bleeding

  7. Endogenous fibrinolysis facilitates clot retraction in vivo.

    Science.gov (United States)

    Samson, Andre L; Alwis, Imala; Maclean, Jessica A A; Priyananda, Pramith; Hawkett, Brian; Schoenwaelder, Simone M; Jackson, Shaun P

    2017-12-07

    Clot retraction refers to the process whereby activated platelets transduce contractile forces onto the fibrin network of a thrombus, which over time increases clot density and decreases clot size. This process is considered important for promoting clot stability and maintaining blood vessel patency. Insights into the mechanisms regulating clot retraction at sites of vascular injury have been hampered by a paucity of in vivo experimental models. By pairing localized vascular injury with thrombin microinjection in the mesenteric circulation of mice, we have demonstrated that the fibrin network of thrombi progressively compacts over a 2-hour period. This was a genuine retraction process, as treating thrombi with blebbistatin to inhibit myosin IIa-mediated platelet contractility prevented shrinkage of the fibrin network. Real-time confocal analysis of fibrinolysis after recombinant tissue-type plasminogen activator (tPA) administration revealed that incomplete proteolysis of fibrin polymers markedly facilitated clot retraction. Similarly, inhibiting endogenous fibrinolysis with tranexamic acid reduced retraction of fibrin polymers in vivo. In vitro clot retraction experiments indicated that subthreshold doses of tPA facilitated clot retraction through a plasmin-dependent mechanism. These effects correlated with changes in the elastic modulus of fibrin clots. These findings define the endogenous fibrinolytic system as an important regulator of clot retraction, and show that promoting clot retraction is a novel and complementary means by which fibrinolytic enzymes can reduce thrombus size. © 2017 by The American Society of Hematology.

  8. Emergency endoscopic variceal ligation in cirrhotic patients with blood clots in the stomach but no active bleeding or stigmata increases the risk of rebleeding

    Directory of Open Access Journals (Sweden)

    Su Jin Kim

    2016-12-01

    Full Text Available Background/Aims This study aimed to evaluate the efficacy and safety of emergency variceal ligation for the prevention of rebleeding in cirrhotic patients who are found on initial endoscopy to have blood clots in the stomach but no actively bleeding esophageal and gastric varices or stigmata. Methods This study included 28 cirrhotic patients who underwent emergency prophylactic EVL and 41 who underwent an elective intervention between January 2009 and June 2014. Clinical outcomes were analyzed, including the rebleeding, 6-week mortality, and rebleeding-free survival rates. Results The rebleeding rate was higher in the emergency than in the elective group (28.6% vs. 7.3%, P=0.041. Multivariate analysis showed that emergency prophylactic EVL (odds ratio [OR] = 7.4, 95% confidence interval [CI]=1.634.8, P=0.012 and Child-Pugh score C (OR=10.6, 95% CI=1.4-80.8, P=0.022 were associated with rebleeding. In the emergency group, the gastric varices were associated with rebleeding (OR=12.0, 95% CI=1.7-83.5, P=0.012. Conclusions Emergency EVL may be associated with variceal rebleeding when blood clots are present in the stomach without active esophageal and gastric variceal bleeding or stigmata. Elective intervention should be considered as a safer strategy for preventing variceal rebleeding in this situation.

  9. Pulsed cavitational therapy using high-frequency ultrasound for the treatment of deep vein thrombosis in an in vitro model of human blood clot

    Science.gov (United States)

    Goudot, G.; Mirault, T.; Arnal, B.; Boisson-Vidal, C.; Le Bonniec, B.; Gaussem, P.; Galloula, A.; Tanter, M.; Messas, E.; Pernot, M.

    2017-12-01

    Post-thrombotic syndrome, a frequent complication of deep venous thrombosis, can be reduced with early vein recanalization. Pulsed cavitational therapy (PCT) using ultrasound is a recent non-invasive approach. We propose to test the efficacy and safety of high-frequency focused PCT for drug-free thrombolysis (thrombotripsy) in a realistic in vitro model of venous thrombosis. To reproduce venous thrombosis conditions, human whole blood was allowed to clot by stasis in silicone tubes (6 mm internal diameter) at a 30 cm H2O pressure, maintained during the whole experiment. We engineered an ultrasound device composed of dual 2.25 MHz transducers centered around a 6 MHz imaging probe. A therapeutic focus was generated at a 3.2 cm depth from the probe. Thrombotripsy was performed by longitudinally scanning the thrombus at three different speeds: 1 mm s-1 (n  =  6) 2 mm s-1 (n  =  6) 3 mm s-1 (n  =  12). Restored outflow was measured every three passages. Filters were placed to evaluate the debris size. Twenty-four occlusive thrombi, of 2.5 cm mean length and 4.4 kPa mean stiffness, were studied. Flow restoration was systematically obtained by nine subsequent passages (4.5 min maximum). By varying the device’s speed, we found an optimal speed of 1 mm s-1 to be efficient for effective recanalization with 90 s (three passages). Within 90 s, flow restoration was of 80, 62 and 74% at respectively 1, 2 and 3 mm s-1. For all groups, cavitation cloud drilled a 1.7 mm mean diameter channel throughout the clot. Debris analysis showed 92% of debris    200 µm.

  10. Transient Expression of Lumbrokinase (PI239 in Tobacco (Nicotiana tabacum Using a Geminivirus-Based Single Replicon System Dissolves Fibrin and Blood Clots

    Directory of Open Access Journals (Sweden)

    Alexia Dickey

    2017-01-01

    Full Text Available Lumbrokinases, a group of fibrinolytic enzymes extracted from earthworm, have been widely used to prevent and treat various cardiovascular diseases. They specifically target fibrin to effectively degrade thrombi without major side effects. Plant expression systems are becoming potential alternative expression platforms for producing pharmaceutical proteins. In this work, a lumbrokinase (PI239 was produced from a plant system. Both wild-type (WT and plant codon-optimized (OP PI239 gene sequences were synthesized and cloned into a geminivirus-based single-vector DNA replicon system. Both vectors were independently expressed in tobacco (Nicotiana tabacum leaves transiently by agroinfiltration. Overexpressed PI239 resulted in sudden tissue necrosis 3 days after infiltration. Remaining proteins were purified through His-tag affinity chromatography and analyzed with SDS-PAGE and Western blot methods. Purified PI239 successfully degraded artificial fibrin with relative activity of 13,400 U/mg when compared with commercial lumbrokinase product. In vitro tests demonstrated that plant-derived PI239 dissolved human blood clots and that the plant expression system is capable of producing functional PI239.

  11. Preventing and Treating Blood Clots

    Science.gov (United States)

    ... Pacific Islander descent. A condition that is inherited, meaning it is passed down from parent to child ... Enoxaparin (Lovenox) Fondaparinux (Arixtra) Tinzaparin (Innohep) Warfarin (multiple brand names). Some of these drugs are taken orally ...

  12. Dynamics of pathologic clot formation: a mathematical model.

    Science.gov (United States)

    Shavlyugin, Evgeny A; Hanin, Leonid G; Khanin, Mikhail A

    2014-01-07

    Recent studies have provided evidence of a significant role of the Hageman factor in pathologic clot formation. Since auto-activation of the Hageman factor triggers the intrinsic coagulation pathway, we study the dynamics of pathologic clot formation considering the intrinsic pathway as the predominant mechanism of this process. Our methodological approach to studying the dynamics of clot formation is based on mathematical modelling. Activation of the blood coagulation cascade, particularly its intrinsic pathway, is known to involve platelets. Therefore, equations accounting for the effects of activated platelets on the intrinsic pathway activation are included in our model. This brings about a considerable increase in the values of kinetic constants involved in the model of the principal biochemical processes resulting in clot formation. The purpose of this study is to elucidate the mechanism of pathologic clot formation. Since the time window of thrombolysis is 3-6h, we hypothesize that in many cases the rate of pathologic clot formation is much lower than that of haemostatic clot. This assumption is used to simplify the mathematical model and to estimate kinetic constants of biochemical reactions that initiate pathologic clot formation. The insights we gained from our mathematical model may lead to new approaches to the prophylaxis of pathologic clot formation. We believe that one of the most efficient ways to prevent pathologic clot formation is simultaneous inhibition of activated factors ХII and ХI. © 2013 Elsevier Ltd. All rights reserved.

  13. Recombinant clotting factors.

    Science.gov (United States)

    Pipe, Steven W

    2008-05-01

    The recombinant era for haemophilia began in the early 1980s with the cloning and subsequent expression of functional proteins for both factors VIII and IX. Efficient production of recombinant clotting factors in mammalian cell culture systems required overcoming significant challenges due to the complex post-translational modifications that were integral to their pro-coagulant function. The quick development and commercialization of recombinant clotting factors was, in part, facilitated by the catastrophic impact of viral contamination of plasma-derived clotting factor concentrates at the time. Since their transition into the clinic, the recombinant versions of both factor VIII and IX have proven to be remarkable facsimiles of their plasma-derived counterparts. The broad adoption of recombinant therapy throughout the developed world has significantly increased the supply of clotting factor concentrates and helped advance aggressive therapeutic interventions such as prophylaxis. The development of recombinant VIIa was a further advance bringing a recombinant option to haemophilia patients with inhibitors. Recombinant DNA technology remains the platform to address ongoing challenges in haemophilia care such as reducing the costs of therapy, increasing the availability to the developing world, and improving the functional properties of these proteins. In turn, the ongoing development of new recombinant clotting factor concentrates is providing alternatives for patients with other inherited bleeding disorders.

  14. Increased Clot Formation in the Absence of Increased Thrombin Generation in Patients with Peripheral Arterial Disease: A Case–Control Study

    Directory of Open Access Journals (Sweden)

    Marie-Claire F. Kleinegris

    2017-04-01

    Full Text Available BackgroundIn peripheral arterial disease (PAD, activation of the hemostatic system may contribute to atherosclerosis progression and atherothrombotic events.ObjectiveThis case–control study assesses the overall coagulation status in PAD patients by evaluating coagulation markers in combination with thrombin generation potential, whole blood (WB clot formation, and fibrinolysis.MethodsIn blood from 40 PAD patients (n = 20 with cardiovascular event within 1 year after initial diagnosis, n = 20 without and 40 apparently healthy controls, thrombin generation was determined in WB and platelet-poor plasma. Whole blood rotational thromboelastometry (ROTEM measurements were triggered with tissue factor with/without tissue plasminogen activator.ResultsWe observed increased levels of erythrocyte sedimentation rate, leukocytes, eosinophil granulocytes, vWF antigen, fibrinogen, and D-dimer in PAD patients (p < 0.05. Markers of thrombin generation potential showed no difference between patients and healthy controls. In PAD patients with event compared to patients without, WB-thrombin generation showed a lower thrombin potential when triggered with 0 and 2.5 pM tissue factor. The ROTEM clotting assay showed significantly faster clot formation and increased clot firmness in PAD patients compared to controls. No significant differences were found for parameters of clot degradation.ConclusionThere are no significant differences between the thrombin generation profiles of PAD patients and healthy controls. Between PAD patients with and without cardiovascular event, the WB thrombin generation appears to differ. Mechanistically, PAD patients show an increased ability to form a stable clot in WB in comparison to healthy controls. This is most likely due to the increased fibrinogen levels related to the inflammation in atherosclerosis, confirming the importance of the inflammation-coagulation axis.

  15. The clotting action of Russell viper venom. 1954.

    Science.gov (United States)

    2016-03-03

    Samuel I. Rapaport made seminal contributions to our basic understanding of blood coagulation. This paper beautifully illustrates his scientific approach through characterization of the clotting activity of venom from Daboia russelii, distinguishing it from the brain “thromboplastic” activity used in the prothrombin time. Using plasma from patients with deficiencies of proconvertin (factor VII), proaccelerin (factor V), antihemophilic globulin (factor VIII), or Christmas factor (factor IX), Rapaport and colleagues demonstrated that the venom's clotting activity does not require factor VII, but does require factor V and lipid. Thus, by combining the venom clotting test with the quick clotting time (prothrombin time), it was possible to diagnose factor VII deficiency. The venom is now known to act by directly activating factor X, and a form of the clotting test is used in the diagnosis of lupus anticoagulants.

  16. [Clotting disorders and preeclampsia].

    Science.gov (United States)

    Ducloy-Bouthors, A-S

    2010-05-01

    Clotting disorders are associated with the severe, early and complicated forms of PE. Compensated hypercoagulability states associated with a thrombocytopenia (PLTdepression of the fibrinolysis appears to contribute towards the hypercoagulable state. The etiological importance of the erythrocyte and leucocyte activation with regards to the abnormal clotting activation is highlighted in the setting of maternal systematic inflammatory disease. The state of compensated coagulopathy found in the PE patient can suffer a pro-coagulatory imbalance because of a quantitative, or a qualitative failure (i.e. thrombophilia) of the physiological coagulation inhibitors, or a combination of both. This disseminated intravascular coagulation, qualified as chronic, is associated with clinically evident signs of foeto-placental unit impairment (i.e. IUGR, foetal death) with or without systemic repercussions in the mother (i.e. renal failure, HELLP syndrome, eclampsia). This set of haemostatic disturbances found in the PE patient is a dynamic phenomenon, which can evolve by the hour therefore requires frequent laboratory investigations. Delivery remains the only curative treatment for these haemostatic disturbances. A better understanding of the aetiology of DIC in PE, an early detection method and a specific identification of the at-risk patients could allow prophylactic and curative treatment. Copyright 2010. Published by Elsevier SAS.

  17. Clot friction variation with fibrin content; implications for resistance to thrombectomy.

    Science.gov (United States)

    Gunning, Gillian M; McArdle, Kevin; Mirza, Mahmood; Duffy, Sharon; Gilvarry, Michael; Brouwer, Patrick A

    2018-01-01

    Despite significant advancements in the procedural efficacy of mechanical thrombectomy in patients with ischemic stroke in recent years, there still remains a portion of the population that does not achieve good recanalization. The reasons for this may be varied. We hypothesized that static friction between the clot and the vessel, or catheter wall might contribute to the difficulty in removing the clot. To determine if there is a relationship between clot composition and the resistance to sliding (friction) which might contribute to resistance to clot removal. As clot composition can vary significantly, we investigated five different types of clot in order to measure their respective frictional properties. To do this, a custom-made testing apparatus was created, consisting of various replaceable low-friction surfaces on which the clots could be placed. The surface was then gradually tilted until the clots began to slide; the angle at which this occurred is related to the coefficient of friction of the clots. The experiment was repeated on a bovine aortic surface in order to confirm the results. We found that fibrin-rich clots (friction than clots with a red blood cell content >20%. This result was confirmed by repeating the experiment on a bovine aortic surface as a representation of the interaction between clots and the arterial wall. The friction properties of clots were found to be related to the content ratio of fibrin to red blood cells. Future imaging techniques that could show fibrin and red blood cell content might help us to predict the 'stickiness' of a clot. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  18. An Antithrombin-Heparin Complex Increases the Anticoagulant Activity of Fibrin Clots

    Directory of Open Access Journals (Sweden)

    Lesley J. Smith

    2008-01-01

    Full Text Available Clotting blood contains fibrin-bound thrombin, which is a major source of procoagulant activity leading to clot extension and further activation of coagulation. When bound to fibrin, thrombin is protected from inhibition by antithrombin (AT + heparin but is neutralized when AT and heparin are covalently linked (ATH. Here, we report the surprising observation that, rather than yielding an inert complex, thrombin-ATH formation converts clots into anticoagulant surfaces that effectively catalyze inhibition of thrombin in the surrounding environment.

  19. Makers of clotting medicine not entitled to liability shield.

    Science.gov (United States)

    1996-02-23

    The Indiana Court of Appeals, Second District, reversed a ruling that protected the manufacturer of a hemophilia blood clotting medicine from legal liability. A boy with hemophilia, known in court records as J.K.B. Jr., contracted HIV from the blood clotting medicine, Factor VIII. His parents sued four pharmaceutical companies, Armour Pharmaceutical Company, Cutter Laboratories, Baxter Healthcare Corporation, and Alpha Therapeutics Corporation, alleging that their products caused J.K.B. Jr.'s death. The companies convinced a Superior Court judge that they were protected under the Indiana Blood Shield Statute. The appeals court ruled that pharmaceutical companies are not included in the Blood Shield Statute. The statute was originally established to protect state-approved blood banks, hospitals, and blood storage facilities because they provide a vital public service.

  20. Photoacoustic monitoring of clot formation during surgery and tumor surgery

    Science.gov (United States)

    Juratli, Mazen A.; Galanzha, Ekaterina I.; Sarimollaoglu, Mustafa; Nedosekin, Dmitry A.; Suen, James Y.; Zharov, Vladimir P.

    2013-03-01

    When a blood vessel is injured, the normal physiological response of the body is to form a clot (thrombus) to prevent blood loss. Alternatively, even without injury to the blood vessel, the pathological condition called thromboembolism may lead to the formation of circulating blood clots (CBCs), also called emboli, which can clog blood vessels throughout the body. Veins of the extremities (venous thromboembolism), lungs (pulmonary embolism ), brain (embolic stroke), heart (myocardial infarction), kidneys, and gastrointestinal tract are often affected. Emboli are also common complications of infection, inflammation, cancer, surgery, radiation and coronary artery bypass grafts. Despite the clear medical significance of CBCs, however, little progress has been made in the development of methods for real-time detection and identification of CBCs. To overcome these limitations, we developed a new modification of in vivo photoacoustic (PA) flow cytometry (PAFC) for real-time detection of white, red, and mixed clots through a transient decrease, increase or fluctuation of PA signal amplitude, respectively. In this work, using PAFC and mouse models, we present for the first time direct evidence that some medical procedures, such as conventional or cancer surgery may initiate the formation of CBCs. In conclusion, the PA diagnostic platform can be used in real-time to define risk factors for cardiovascular diseases, assist in the prognosis and potential prevention of stroke by using a well-timed therapy or as a clot count as a marker of therapy efficacy.

  1. Randomized Comparison of the Therapeutic Effect of Acupuncture, Massage, and Tachibana-Style-Method on Stiff Shoulders by Measuring Muscle Firmness, VAS, Pulse, and Blood Pressure

    Directory of Open Access Journals (Sweden)

    Kazuhiro Tachibana

    2012-01-01

    Full Text Available To compare the therapeutic efficacy of acupuncture, massage, and Tachibana-Ryojutsu (one of Japanese traditional body balance therapy techniques (SEITAI, on stiff shoulders, the subjects’ muscle firmness, blood pressure, pulse, VAS, and body temperature were measured before and after the treatment. Forty-seven volunteer subjects gave written informed consent to participate in this study. The subjects were randomly divided into three groups to receive acupuncture, massage, or Tachibana-Ryojutsu. Each therapy lasted for 90 seconds. The acupuncture treatment was applied by a retaining-needle at GB-21, massage was conducted softly on the shoulders, and Tachibana-Ryojutsu treated only the muscles and joints from the legs to buttocks without touching the shoulders or backs. The study indicated that the muscle firmness and VAS of the Tachibana-Ryojutsu group decreased significantly in comparison with the acupuncture and massage groups after treatment.

  2. High blood pressure - infants

    Science.gov (United States)

    Hypertension - infants ... and blood vessels The health of the kidneys High blood pressure in infants may be due to kidney or ... blood vessel of the kidney) In newborn babies, high blood pressure is often caused by a blood clot in ...

  3. Understand Your Risk for Excessive Blood Clotting

    Science.gov (United States)

    ... travel to the arteries or veins in the brain, heart, kidneys, lungs and limbs, which in turn can cause heart attack, stroke, damage to the body’s organs or even death. Acquired Risk Factors Smoking Overweight and obesity Pregnancy Prolonged ...

  4. Factor XIII stiffens fibrin clots by causing fiber compaction.

    Science.gov (United States)

    Kurniawan, N A; Grimbergen, J; Koopman, J; Koenderink, G H

    2014-10-01

    Factor XIII-induced cross-linking has long been associated with the ability of fibrin blood clots to resist mechanical deformation, but how FXIII can directly modulate clot stiffness is unknown. We hypothesized that FXIII affects the self-assembly of fibrin fibers by altering the lateral association between protofibrils. To test this hypothesis, we studied the cross-linking kinetics and the structural evolution of the fibers and clots during the formation of plasma-derived and recombinant fibrins by using light scattering, and the response of the clots to mechanical stresses by using rheology. We show that the lateral aggregation of fibrin protofibrils initially results in the formation of floppy fibril bundles, which then compact to form tight and more rigid fibers. The first stage is reflected in a fast (10 min) increase in clot stiffness, whereas the compaction phase is characterized by a slow (hours) development of clot stiffness. Inhibition of FXIII completely abrogates the slow compaction. FXIII strongly increases the linear elastic modulus of the clots, but does not affect the non-linear response at large deformations. We propose a multiscale structural model whereby FXIII-mediated cross-linking tightens the coupling between the protofibrils within a fibrin fiber, thus making the fiber stiffer and less porous. At small strains, fiber stiffening enhances clot stiffness, because the clot response is governed by the entropic elasticity of the fibers, but once the clot is sufficiently stressed, the modulus is independent of protofibril coupling, because clot stiffness is governed by individual protofibril stretching. © 2014 International Society on Thrombosis and Haemostasis.

  5. Fibrin Clots Are Equilibrium Polymers That Can Be Remodeled Without Proteolytic Digestion

    OpenAIRE

    Chernysh, Irina N.; Nagaswami, Chandrasekaran; Purohit, Prashant K.; Weisel, John W.

    2012-01-01

    Fibrin polymerization is a necessary part of hemostasis but clots can obstruct blood vessels and cause heart attacks and strokes. The polymerization reactions are specific and controlled, involving strong knob-into-hole interactions to convert soluble fibrinogen into insoluble fibrin. It has long been assumed that clots and thrombi are stable structures until proteolytic digestion. On the contrary, using the technique of fluorescence recovery after photobleaching, we demonstrate here that the...

  6. Antithrombin III blood test

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003661.htm Antithrombin III blood test To use the sharing features on this page, ... a protein that helps control blood clotting. A blood test can determine the amount of AT III present ...

  7. The effect of sepsis and septic shock on the viscoelastic properties of clot quality and mass using rotational thromboelastometry: A prospective observational study.

    Science.gov (United States)

    Davies, Gareth R; Lawrence, Matthew; Pillai, Suresh; Mills, Gavin M; Aubrey, Robert; Thomas, Dafydd; Williams, Rhodri; Morris, Keith; Evans, Phillip Adrian

    2018-04-01

    The study purpose was to define changes in coagulation across the sepsis spectrum using rotational thromboelastometry (ROTEM). Sepsis patients were recruited on admission to the Emergency Department and Intensive Care Units of a large teaching hospital in Wales. ROTEM markers of clot development and fibrinolysis were determined, as well as standard coagulation markers. A healthy control group matched for age and gender was also recruited (n=44). 100 patients were recruited (50 sepsis, 20 severe sepsis and 30 septic shock). Maximum clot firmness was significantly higher in the sepsis (p<0.001) and severe sepsis (p=0.012) groups than the healthy control (71.6±4.5 and 70.4±4.1 vs 64.4 respectively). In septic shock there was prolonged clot development; however, maximum clot firmness remained normal. Fibrinolytic function was significantly impaired in septic shock, which was also significantly associated with 28-day mortality (p<0.001). ROTEM indicated significantly enhanced clot structural development in sepsis and severe sepsis, which could be indicative of a hypercoagulable phase. In septic shock, despite there being a prolongation of clotting pathways and impaired fibrinolysis, clot mass was comparably normal, suggestive of the development of a clot with healthy characteristics. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Intrinsic clotting factors in dependency of age, sex, body mass index, and oral contraceptives: definition and risk of elevated clotting factor levels.

    Science.gov (United States)

    Luxembourg, Beate; Schmitt, Joern; Humpich, Marek; Glowatzki, Matthias; Seifried, Erhard; Lindhoff-Last, Edelgard

    2009-10-01

    Elevated clotting factors have been demonstrated to be a risk factor for venous thromboembolism (VTE). The aim of our study was to investigate the impact of age, sex, body mass index, and oral contraceptives on the clotting factor activities of factors VIII, IX, XI, and XII and their impact on the cutoff definition and risk of VTE associated with elevated clotting factors. Factor VIII, IX, XI, and XII activities were measured in 499 blood donors and 286 patients with VTE. Age and body mass index predicted significantly and independently the clotting factor activities of factors VIII, IX, and XI, whereas use of oral contraceptives predicted factor IX, XI, and XII levels. Percentiles of clotting factor activities, which are often used for the cutoff definition of elevated clotting factors, varied due to the effect of age, body mass index, and oral contraceptives. The adjusted odds ratios for VTE were 10.3 [95% confidence interval (CI) 5.1-20.7], 6.1 (95% CI 3.1-12.0), and 3.3 (95% CI 1.9-5.8) for elevated factors VIII, IX, and XI, respectively. Furthermore, our study demonstrates for the first time that elevated factor XII is associated with an increased risk of VTE (adjusted odds ratio 2.9, 95% CI 1.6-5.3).

  9. The application of large amplitude oscillatory stress in a study of fully formed fibrin clots

    Science.gov (United States)

    Lamer, T. F.; Thomas, B. R.; Curtis, D. J.; Badiei, N.; Williams, P. R.; Hawkins, K.

    2017-12-01

    The suitability of controlled stress large amplitude oscillatory shear (LAOStress) for the characterisation of the nonlinear viscoelastic properties of fully formed fibrin clots is investigated. Capturing the rich nonlinear viscoelastic behaviour of the fibrin network is important for understanding the structural behaviour of clots formed in blood vessels which are exposed to a wide range of shear stresses. We report, for the first time, that artefacts due to ringing exist in both the sample stress and strain waveforms of a LAOStress measurement which will lead to errors in the calculation of nonlinear viscoelastic properties. The process of smoothing the waveforms eliminates these artefacts whilst retaining essential rheological information. Furthermore, we demonstrate the potential of LAOStress for characterising the nonlinear viscoelastic properties of fibrin clots in response to incremental increases of applied stress up to the point of fracture. Alternating LAOStress and small amplitude oscillatory shear measurements provide detailed information of reversible and irreversible structural changes of the fibrin clot as a consequence of elevated levels of stress. We relate these findings to previous studies involving large scale deformations of fibrin clots. The LAOStress technique may provide useful information to help understand why some blood clots formed in vessels are stable (such as in deep vein thrombosis) and others break off (leading to a life threatening pulmonary embolism).

  10. Experimental and imaging techniques for examining fibrin clot structures in normal and diseased states.

    Science.gov (United States)

    Fan, Natalie K; Keegan, Philip M; Platt, Manu O; Averett, Rodney D

    2015-04-01

    Fibrin is an extracellular matrix protein that is responsible for maintaining the structural integrity of blood clots. Much research has been done on fibrin in the past years to include the investigation of synthesis, structure-function, and lysis of clots. However, there is still much unknown about the morphological and structural features of clots that ensue from patients with disease. In this research study, experimental techniques are presented that allow for the examination of morphological differences of abnormal clot structures due to diseased states such as diabetes and sickle cell anemia. Our study focuses on the preparation and evaluation of fibrin clots in order to assess morphological differences using various experimental assays and confocal microscopy. In addition, a method is also described that allows for continuous, real-time calculation of lysis rates in fibrin clots. The techniques described herein are important for researchers and clinicians seeking to elucidate comorbid thrombotic pathologies such as myocardial infarctions, ischemic heart disease, and strokes in patients with diabetes or sickle cell disease.

  11. Artificial Stroke Clots: How Wide is the Gap to the Real World?

    Science.gov (United States)

    Berndt, Maria; Prothmann, Sascha; Maegerlein, Christian; Oberdieck, Paul; Zimmer, Claus; Hegge, Barbara; Pelisek, Jaroslav; Schirmer, Lucas; Poppert, Holger; Boeckh-Behrens, Tobias

    2018-02-01

    Especially since the establishment of mechanical thrombectomy as part of standard stroke therapy, artificial thrombi have become important in the training of interventionalists as well as for the development and testing of devices. So far, these in vitro clots have lacked direct comparisons with ex vivo thrombi. We therefore compared the histologic appearance of dynamically produced clots with that of stroke thrombi acquired during mechanical recanalization. Thrombi of 145 consecutive patients with stroke with large-vessel occlusions were histologically compared with 10 artificial clots, dynamically created from human blood and pig's blood using a Chandler loop system. Quantified FP/RBC ratios (fibrin/platelets divided by red blood cell fraction) and white blood cell (WBC) fractions were identified and compared between artificial (human and pig) and ex vivo thrombi obtained from patients with various stroke causes. There were no significant differences in the analysis of FP/RBC ratios between artificial thrombi and ex vivo thrombi (P = 0.42) or in the more precise analyses considering etiologic subgroups. Distinct differences were observed for the WBC fraction, with lower values in artificial thrombi (median, 1.34%) than in ex vivo thrombi (median, 5%) (P < 0.001). The main clot components, FP and RBC, are presumably the most influential factors for clot stability and mechanical resistance. Similarities between artificially generated and ex vivo stroke clots (and when considering different stroke subgroups) support the usefulness of these artificial thrombi in the pre-evaluation of thrombus extraction devices and as appropriate training material. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Strong Firms Lobby, Weak Firms Bribe

    DEFF Research Database (Denmark)

    Bennedsen, Morten; Feldmann, Sven E.; Lassen, David Dreyer

    We use survey responses by firms to examine the firm-level determinants and effects of political influence, their perception of corruption and prevalence of bribe paying. We find that: (a) measures of political influence and corruption/bribes are uncorrelated at the firm level; (b) firms...... that are larger, older, exporting, government-owned, are widely held and/or have fewer competitors, have more political influence, perceive corruption to be less of a problem and pay bribes less often; (c) influence increases sales and government subsidies and in general makes the firm have a more positive view...

  13. The effects of Aloe vera [gel] on clotting time, prothrombin time and ...

    African Journals Online (AJOL)

    Background: Published reports on the effects of Aloe vera gel on blood coagulation in experimental animals are relatively scanty. Aim: To determine the effect of Aloe vera gel on clotting time, prothrombin time and plasma fibrinogen concentration in albino Wistar rats. Methods: A total of 28 adult albino Wistar rats divided ...

  14. Effects of exercise intensity on clot microstructure and mechanical properties in healthy individuals.

    Science.gov (United States)

    Davies, N A; Llwyd, O; Brugniaux, J V; Davies, G R; Marley, C J; Hodson, D; Lawrence, M J; D'Silva, L A; Morris, R H K; Hawkins, K; Williams, P R; Bailey, D M; Evans, P A

    2016-07-01

    Exercise is well established to lead to exercise-induced hypercoagulability, as demonstrated by kinetic coagulation markers. It remains unclear as to whether exercise-induces changes lead in clot development and increased polymerisation. Fractal dimension (df) has been shown to act as a marker of clot microstructure and mechanical properties, and may provide a more meaningful method of determining the relationship between exercise-induced hypercoagulability and potential clot development. df was measured in 24 healthy individuals prior to, after 5min of submaximal exercise, following maximal exercise, 45min of passive recovery and following 60min of recovery. Results were compared with conventional markers of coagulation, fibrinolysis and SEM images. Significantly increased df was observed following exercise, returning to resting values following 60min of recovery. The relationship between df and mature clot microstructure was confirmed by SEM: higher df was associated with dense clots formed of smaller fibrin fibres immediately following exercise compared to at rest. Conventional markers of coagulation confirmed findings of previous studies. This study demonstrates that df is a sensitive technique which quantifies the structure and properties of blood clots following exercise. In healthy individuals, the haemostatic balance between coagulation and fibrinolysis is maintained in equilibrium following exercise. In individuals with underlying vascular damage who participate in exercise, this equilibrium may be displaced and lead to enhanced clot formation and a prothrombotic state. df may therefore have the potential to not only quantify hypercoagulability, but may also be useful in screening these individuals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Influence of clot retraction on the short-T2 appearance of an acute hematoma

    International Nuclear Information System (INIS)

    Clark, R.A.; Watanabe, A.T.; Bradley, W.G. Jr.; Roberts, J.D.

    1988-01-01

    The short-T2 appearance of acute hematomas has been previously explained solely by water diffusing in and out of deoxyhemoglobin-containing red cells. According to this theory, the maximum effect occurs at a 50% hematocrit and should be absent at 100% hematocrit. This theory fails to take clot retraction per se into account. The authors have confirmed that the shortest T2 of heparinized blood (deoxyhemoglobin form by Raman spectroscopy) occurs at 50% hematocrit. Retraction of nonparamagnetic plasma and oxyhemogloblin clots over 24 hours shortens T2 by 10%-40% at 90 MHz, depending on the platelet concentration. The additional T2 shortening observed after formation of deoxyhemoglobin is thus primarily due to clot retraction

  16. Evaluation of the effects of levobupivacaine on clotting and fibrinolysis using thromboelastography.

    LENUS (Irish Health Repository)

    Leonard, S A

    2012-02-03

    Amide local anaesthetics inhibit platelet function. We hypothesized that residual anaesthetic in the epidural space could decrease efficacy of an epidural blood patch in preventing postdural puncture headache. Levobupivacaine has recently been approved for epidural anaesthesia. Its effects on coagulation have not previously been studied. The aim of this study was to determine the effects of levobupivacaine on clotting using thromboelastography. Ten ASA Class I volunteers were studied. Venous blood samples were analysed using a Haemoscope 2000D TEG analyser. Whole blood, a 50% saline control and two levobupivacaine solutions (2.5 mg mL(-1) and 2.5 microg mL(-1) in blood) were compared. The former reproduces that produced in the epidural space by blood (20 mL for an epidural blood patch) and levobupivacaine 0.5% (20 mL). The latter approximates plasma concentrations following epidural injection of levobupivacaine 0.5% (20 mL). P < 0.05 was considered significant. Maximum amplitude (MA), a measure of clot strength, is decreased by levobupivacaine 2.5 mg mL(-1). Levobupivacaine 2.5 mg mL(-1) decreases clot strength and may reduce efficacy of a prophylactic epidural blood patch.

  17. Tranexamic acid combined with recombinant factor VIII increases clot resistance to accelerated fibrinolysis in severe hemophilia A

    DEFF Research Database (Denmark)

    Hvas, Anne-Mette; Sørensen, Hanne Thykjær; Norengaard, Lisbeth

    2007-01-01

    BACKGROUND: Most patients with severe hemophilia A suffer from a profoundly compromised hemostatic response. In addition to both the delayed and slow development of a clot, previous studies have documented that severe hemophilia A is also associated with reduced clot stability. OBJECTIVES: We...... examined whether the clot stability in hemophiliacs could be improved by treatment with tranexamic acid (TXA) in combination with recombinant factor VIII (rFVIII). PATIENTS/METHODS: Baseline blood samples were obtained from eight males with severe hemophilia A. Thereafter, a bolus injection of r...... the elasticity curve increased 5-fold after rFVIII and 24-fold after addition of TXA. CONCLUSIONS: The study demonstrates that simultaneous treatment with TXA and rFVIII significantly improves the clot stability in patients with hemophilia A. Udgivelsesdato: December...

  18. Effect of low frequency ultrasound on combined rt-PA and eptifibatide thrombolysis in human clots.

    Science.gov (United States)

    Meunier, Jason M; Holland, Christy K; Pancioli, Arthur M; Lindsell, Christopher J; Shaw, George J

    2009-01-01

    Fibrinolytics such as recombinant tissue plasminogen activator (rt-PA) are used to treat thrombotic disease such as acute myocardial infarction (AMI) and ischemic stroke. Interest in increasing efficacy and reducing side effects has led to the study of adjuncts such as GP IIb-IIIa inhibitors and ultrasound (US) enhanced thrombolysis. Currently, GP IIb-IIIa inhibitor and fibrinolytic treatment are often used in AMI, and are under investigation for stroke treatment. However, little is known of the efficacy of combined GP IIb-IIIa inhibitor, fibrinolytic and ultrasound treatment. We measure the lytic efficacy of rt-PA, eptifibatide (Epf) and 120 kHz ultrasound treatment in an in-vitro human clot model. Blood was drawn from 15 subjects after IRB approval. Clots were made in 20 microL pipettes, and placed in a water tank for microscopic visualization during lytic treatment. Clots were exposed to control, rt-PA (rt-PA), eptifibatide (Epf), or rt-PA+eptifibatide (rt-PA + Epf), with (+US) or without (-US) ultrasound for 30 minutes at 37 degrees C in human plasma. Clot lysis was measured over time, using a microscopic imaging technique. The fractional clot loss (FCL) and initial lytic rate (LR) were used to quantify lytic efficacy. LR values for (- US) treated clots were 0.8+/-0.1(control), 1.8+/-0.3 (Epf), 1.5+/-0.2 (rt-PA), and 1.3+/-0.4 (rt-PA + Epf) (% clot width/minute) respectively. In comparison, the (+ US) group exhibited LR values of 1.6+/-0.2 (control), 4.3+/-0.4 (Epf), 6.3+/-0.4 (rt-PA), and 4.6+/-0.6 (rt-PA + Epf). For (- US) treated clots, FCL was 6.0+/-0.8 (control), 9.2+/-2.5 (Epf), 15.6+/-1.7 (rt-PA), and 28.0+/-2.2% (rt-PA + Epf) respectively. FCL for (+ US) clots was 13.5+/-2.4 (control), 20.7+/-6.4 (Epf), 44.4+/-3.6 (rt-PA) and 30.3+/-3.6% (rt-PA + Epf) respectively. Although the addition of eptifibatide enhances the in-vitro lytic efficacy of rt-PA in the absence of ultrasound, the efficacy of ultrasound and rt-PA is greater than that of combined

  19. Clot dynamics and mortality: The MA-R ratio.

    Science.gov (United States)

    Savage, Stephanie A; Zarzaur, Ben L; Pohlman, Timothy H; Brewer, Brian L; Magnotti, Louis J; Croce, Martin A; Lim, Garrett H; Martin, Ali C

    2017-10-01

    The coagulopathy of trauma, illustrated by a short R-time, is common and well understood. The physiology behind this may be early thrombin burst with rapid clot formation. Rapid consumption of fibrinogen, however, may result in weak clot and substrate depletion, resulting in low MA. While these characteristics are interesting, utilizing thromboelastography (TEG) to identify those at risk of subsequent bleeding diathesis, especially in those who do not demonstrate early signs of physiologic derangement, is challenging. We have developed a novel ratio utilizing TEG values to describe patients at specific risk of traumatic coagulopathy. The purpose of this study was to create a single TEG value, which would reflect both the hypercoagulability and hypocoagulability of TIC. We hypothesized that this ratio, at admission, would be indicative of TIC and predictive of both blood product transfusion volumes and subsequent mortality. Patients admitted via the highest activation criteria at one of two Level I trauma centers were included if they received at least 1 unit of packed red blood cells in the first 24 hours of admission. The admission TEG was collected, and a ratio was calculated by dividing the MA by the R-time (MA-R). MA-R quartiles were developed, and multivariable logistic regression was utilized to determine odds of mortality. Three hundred thirty patients with admission TEG were included. In all patients, median age was 35 years (interquartile range, 25-54 years), Injury Severity Score (ISS) was 20 (interquartile range, 13-29), 76% were male, and 43% had penetrating trauma. The MA-R groups were based on quartiles. Multivariable analysis, controlling for mechanism of injury, ISS, and admission pH, showed that increasing ratios were associated with decreased odds of death. The lowest MA-R ratios were also significantly associated with higher ISS, higher rates of blunt injury, and higher plasma utilization without a significant difference in packed red blood cell

  20. The Influence of a Micropolar Fluid on Peristaltic Transport in an Annulus: Application of the Clot Model

    Directory of Open Access Journals (Sweden)

    Kh. S. Mekheimer

    2008-01-01

    Full Text Available A serious pathological condition is encountered when some blood constituents deposited on the blood vessels get detached from the wall, join the blood stream again and form a clot. Study of the peristaltic transport of a micropolar fluid in an annular region is investigated under low Reynolds number and long wavelength approximations. We model a small artery as a tube having a sinusoidal wave travelling down its wall and a clot model inside it. Closed form solutions are obtained for the velocity and the microrotation components, as well as the stream function, and they contain new additional parameters, namely, δ, the height of the clot, N, the coupling number and m, the micropolar parameter. The pressure rise and friction force on the inner and the outer tubes have been discussed for various values of the physical parameters of interest.

  1. Procurement with specialized firms

    DEFF Research Database (Denmark)

    Boone, Jan; Schottmüller, Christoph

    2016-01-01

    This paper analyzes optimal procurement mechanisms when firms are specialized. The procurement agency has incomplete information concerning the firms’ cost functions and values high quality as well as low price. Lower type firms are cheaper (more expensive) than higher type firms when providing l...

  2. Performance of Patenting Firms

    DEFF Research Database (Denmark)

    Madsen, Erik Strøjer; Smith, Valdemar; Nielsen, Anders Østergaard

    2000-01-01

    Most countries focus on industries with high technology and the governments grant subsidies to innovating firms. However, there has been remarkable few studies of the performance of innovative firms or industries. This study examines the performance of patent active firms compared to the non-patenting...... firms within the manufacturing sector in Denmark. Performance is measured both by growth in employment as well as in the return on equity and profit share in turnover. The results suggest that differences in performance of patenting and non-patenting firms are very small, which questions the political...

  3. {sup 99m}Tc-NC100668, a new tracer for imaging venous thromboemboli: pre-clinical biodistribution and incorporation into plasma clots in vivo and in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, David [Grove Centre, Research and Development, GE Healthcare Bio-Sciences, Little Chalfont (United Kingdom); Uppsala University Hospital, Institution of Oncology, Radiology and Clinical Immunology, Section of Radiology, Uppsala (Sweden); Lewis, Joanne; Battle, Mark; Lear, Rochelle; Farrar, Gill; Barnett, D.J.; Godden, Vanessa; Oliveira, Alexandra; Coombes, Catherine [Grove Centre, Research and Development, GE Healthcare Bio-Sciences, Little Chalfont (United Kingdom); Ahlstroem, Haakan [Uppsala University Hospital, Institution of Oncology, Radiology and Clinical Immunology, Section of Radiology, Uppsala (Sweden)

    2006-11-15

    {sup 99m}Tc-NC100668 is a new radiotracer being developed to aid the diagnosis of thromboembolism. The structure of NC100668 is similar to a region of human {alpha}{sub 2}-antiplasmin, which is a substrate for factor XIIIa (FXIIIa). The purpose of this study was to confirm the uptake of {sup 99m}Tc-NC100668 into forming plasma clot and to establish the biodistribution of {sup 99m}Tc-NC100668 in Wistar rats. The in vitro plasma clot uptake of {sup 99m}Tc-NC100668 and other compounds with known affinities to FXIIIa was measured using a plasma clot assay. The biodistribution and blood clot uptake of radioactivity of {sup 99m}Tc-NC100668 in normal Wistar rats and those bearing experimentally induced deep vein thrombi were investigated. The in vitro uptake of {sup 99m}Tc-NC100668 was greater than that for [{sup 14}C]dansyl cadaverine, a known substrate of FXIIIa in the plasma clot assay. The biodistribution of {sup 99m}Tc-NC100668 in male and female Wistar rats up to 24 h p.i. showed that radioactivity was rapidly excreted, predominantly into the urine, with very little background tissue retention. In vivo the uptake and retention of {sup 99m}Tc-NC100668 into the blood clot was greater than could be accounted for by non-specific accumulation of the radiotracer within the blood clot. {sup 99m}Tc-NC100668 was retained by plasma clots in vitro and blood clots in vivo. No significant tissue retention which could interfere with the ability to image thrombi in vivo was observed. This evidence suggests that {sup 99m}Tc-NC100668 might be useful in the detection of thromboembolism. (orig.)

  4. Determining Human Clot Lysis Time (in vitro with Plasminogen/Plasmin from Four Species (Human, Bovine, Goat, and Swine

    Directory of Open Access Journals (Sweden)

    Omaira Cañas Bermúdez

    2015-05-01

    Full Text Available Cardiovascular disease is the leading cause of death worldwide, including failures in the plasminogen/plasmin system which is an important factor in poor lysis of blood clots. This article studies the fibrinolytic system in four species of mammals, and it identifies human plasminogen with highest thrombolysis efficiency. It examines plasminogen from four species (human, bovine, goat, and swine and identifies the most efficient one in human clot lysis in vitro. All plasminogens were identically purified by affinity chromatography. Human fibrinogen was purified by fractionation with ethanol. The purification of both plasminogen and fibrinogen was characterized by one-dimensional SDS-PAGE (10%. Human clot formation in vitro and its dissolution by plasminogen/plasmin consisted of determining lysis time from clot formation to its dilution. Purification of proteins showed greater than 95% purity, human plasminogen showed greater ability to lyse clot than animal plasminogen. The article concludes that human plasminogen/plasmin has the greatest catalysis and efficiency, as it dissolves human clot up to three times faster than that of irrational species.

  5. Quantification of bone marrow plasma cell infiltration in multiple myeloma: usefulness of bone marrow aspirate clot with CD138 immunohistochemistry.

    Science.gov (United States)

    Matsue, Kosei; Matsue, Yuya; Kumata, Kaoru; Usui, Yoshiaki; Suehara, Yasuhito; Fukumoto, Kota; Fujisawa, Manabu; Narita, Kentaro; Takeuchi, Masami

    2017-09-01

    Accurate quantification of plasma cells (PCs) in bone marrow (BM) is critical for diagnosis and assessment of treatment response in patients with multiple myeloma (MM). We compared the % of BM PC quantified by 250 cell differential count on May-Giemsa-stained BM smears, by counting 500 - 2500 cells in 2 - 5 representative microscopy fields in CD138-immunostained BM clot and biopsy sections, and CD38/CD45/CD138 gated BM PCs on flow cytometry (FCM) in 150 sets of BM samples from 120 patients. Percentages of PC were significantly correlated between BM biopsy and clot, and between smear and FCM (r = 0.96, 0.93, respectively). However, quantification by smear and FCM significantly underestimated the PC compared to biopsy or clot, and the degree of underestimation increased with blood dilution. FCM consistently showed lower % of PC compared to aspirate smears. Fifty-nine of 103 patients with M-protein level smoldering MM when reassessed using CD138-stained biopsy/clot sections. Among the 72 patients with sMM diagnosed by BM biopsy and/clot, three patients (4.2%) had extensive BM infiltration of PC (≥ 60%) and required treatment. Our data clearly showed the necessity of CD138 immunostaining of BM biopsy/clot specimens for correct diagnosis of MM and related disorders. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Fibrin clot adhesion to root surface treated with tetracycline hydrochloride and ethylenediaminetetraacetic acid: A scanning electron microscopic study

    Directory of Open Access Journals (Sweden)

    Chandran Preeja

    2013-01-01

    Full Text Available Background: Connective tissue attachment following periodontal regenerative surgery is directly related to the attachment of fibrin clot on to the root surface during early wound healing events.The adhesion of fibrin clot to the root surface affected by periodontal disease depends on the biologic acceptance of the root surface which can be accomplished by various root conditioning procedures during periodontal therapy. The present in vitro study has been designed to evaluate and compare the degree of fibrin clot adhesion to root surfaces treated with root conditioning agents tetracycline hydrochloride and ethylenediaminetetraacetic acid (EDTA. Materials and Methods: A total of 30 dentin blocks are divided into three groups and treated with tetracycline hydrochloride, EDTA and phosphate buffered saline and a drop of blood is added to each dentin block. The dentin blocks are then prepared for scanning electron microscopic analysis and examined for the degree of fibrin network frmation and entrapped erythrocytes. Results: The degree of fibrin clot adhesion was highest with tetracycline hydrochloride group, then with control group and least with EDTA treated group. Conclusion: According to the results of the present study, root conditioning with tetracycline hydrochloride produces a biologically acceptable root surface with enhanced fibrin clot adhesion, which is a critical step in early wound healing process. EDTA gel appears less effective in producing a root surface necessary for the adhesion of fibrin clot. The control without any root conditioning procedure showed poor fibrin clot adhesion when compared to tetracycline treated group, but when compared to EDTA treated group the fibrin clot adhesion was slightly better.

  7. Changes in clot lysis levels of reteplase and streptokinase following continuous wave ultrasound exposure, at ultrasound intensities following attenuation from the skull bone

    Directory of Open Access Journals (Sweden)

    Roijer Anders

    2008-08-01

    Full Text Available Abstract Background Ultrasound (US has been used to enhance thrombolytic therapy in the treatment of stroke. Considerable attenuation of US intensity is however noted if US is applied over the temporal bone. The aim of this study was therefore to explore possible changes in the effect of thrombolytic drugs during low-intensity, high-frequency continuous-wave ultrasound (CW-US exposure. Methods Clots were made from fresh venous blood drawn from healthy volunteers. Each clot was made from 1.4 ml blood and left to coagulate for 1 hour in a plastic test-tube. The thrombolytic drugs used were, 3600 IU streptokinase (SK or 0.25 U reteplase (r-PA, which were mixed in 160 ml 0.9% NaCl solution. Continuous-wave US exposure was applied at a frequency of 1 MHz and intensities ranging from 0.0125 to 1.2 W/cm2. For each thrombolytic drug (n = 2, SK and r-PA and each intensity (n = 9 interventional clots (US-exposed, n = 6 were submerged in thrombolytic solution and exposed to CW-US while control clots (also submerged in thrombolytic solution, n = 6 were left unexposed to US. To evaluate the effect on clot lysis, the haemoglobin (Hb released from each clot was measured every 20 min for 1 hour (20, 40 and 60 min. The Hb content (mg released was estimated by spectrophotometry at 540 nm. The difference in effect on clot lysis was expressed as the difference in the amount of Hb released between pairs of US-exposed clots and control clots. Statistical analysis was performed using Wilcoxon's signed rank test. Results Continuous-wave ultrasound significantly decreased the effects of SK at intensities of 0.9 and 1.2 W/cm2 at all times (P 2 and at 1.2 W/cm2, following 40 min exposure at 0.3, 0.6, 0.9 and at 1.2 W/cm2, and following 60 min of exposure at 0.05 0.3, 0.6, 0.9 and at 1.2 W/cm2 (all P Conclusion Increasing intensities of CW-US exposure resulted in increased clot lysis of r-PA-treated blood clots, but decreased clot lysis of SK-treated clots.

  8. Foreign Firms, Domestic Wages

    DEFF Research Database (Denmark)

    Malchow-Møller, Nikolaj; Markusen, James R.; Schjerning, Bertel

    Foreign-owned firms are often hypothesized to generate productivity "spillovers" to the host country, but both theoretical micro-foundations and empirical evidence for this are limited. We develop a heterogeneous-firm model in which ex-ante identical workers learn from their employers in proporti...... characteristics, but, as expected, are reduced significantly when controlling for unobservable firm heterogeneity. Furthermore, acquired skills in foreign-owned and large firms appear to be transferable to both subsequent wage work and self-employment......Foreign-owned firms are often hypothesized to generate productivity "spillovers" to the host country, but both theoretical micro-foundations and empirical evidence for this are limited. We develop a heterogeneous-firm model in which ex-ante identical workers learn from their employers in proportion...

  9. Cloning and expression of hybrid streptokinase towards clot-specific activity.

    Science.gov (United States)

    Buniya, Harith K; Murugan, Vadivel; Thangadurai, Chinnathambi

    2014-03-01

    Streptokinase (SK) is a thrombolytic agent that is widely used to treat myocardial infarction and pulmonary embolism. The lack of fibrin specificity of SK for the clot lysis is one of the limitations of SK. In this study, we have incorporated the finger and Kringle 2 domains from the human tissue type plasminogen activator gene (t-PA) at the 5' end of the SK gene. These domains are responsible for specific binding to fibrin. We have used the pRSETB vector in an attempt to express the hybrid streptokinase possessing specificity for fibrin. On this regard, three hybrid streptokinase were constructed and expressed in Escherichia coli BL21 (DE3): the finger domain with SK (FSK), the Kringle 2 domain with SK (KSK) and the finger domain+Kringle 2 with SK (FKSK). The activities of the hybrid SKs were assessed by caseinolytic assay and clot lysis assay. All hybrid SKs were found to activate plasminogen in the caseinolytic plate assay. In the clot lysis assay, KSK and FSK were able to dissolute human blood and artificial clots in a fibrin-dependent manner unlike the SK and FKSK proteins. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Gender Segregation Small Firms

    OpenAIRE

    Kenneth R Troske; William J Carrington

    1992-01-01

    This paper studies interfirm gender segregation in a unique sample of small employers. We focus on small firms because previous research on interfirm segregation has studied only large firms and because it is easier to link the demographic characteristics of employers and employees in small firms. This latter feature permits an assessment of the role of employer discrimination in creating gender segregation. Our first finding is that interfirm segregation is prevalent among small employers. I...

  11. Thermodynamics of firms' growth

    Science.gov (United States)

    Zambrano, Eduardo; Hernando, Alberto; Hernando, Ricardo; Plastino, Angelo

    2015-01-01

    The distribution of firms' growth and firms' sizes is a topic under intense scrutiny. In this paper, we show that a thermodynamic model based on the maximum entropy principle, with dynamical prior information, can be constructed that adequately describes the dynamics and distribution of firms' growth. Our theoretical framework is tested against a comprehensive database of Spanish firms, which covers, to a very large extent, Spain's economic activity, with a total of 1 155 142 firms evolving along a full decade. We show that the empirical exponent of Pareto's law, a rule often observed in the rank distribution of large-size firms, is explained by the capacity of economic system for creating/destroying firms, and that can be used to measure the health of a capitalist-based economy. Indeed, our model predicts that when the exponent is larger than 1, creation of firms is favoured; when it is smaller than 1, destruction of firms is favoured instead; and when it equals 1 (matching Zipf's law), the system is in a full macroeconomic equilibrium, entailing ‘free’ creation and/or destruction of firms. For medium and smaller firm sizes, the dynamical regime changes, the whole distribution can no longer be fitted to a single simple analytical form and numerical prediction is required. Our model constitutes the basis for a full predictive framework regarding the economic evolution of an ensemble of firms. Such a structure can be potentially used to develop simulations and test hypothetical scenarios, such as economic crisis or the response to specific policy measures. PMID:26510828

  12. The market for firms

    DEFF Research Database (Denmark)

    Davis, Jerome Dean; Keiding, Hans

    2010-01-01

    In this paper, the pricing and sale of firms is approached from the owners' point of view. It is shown that there are very strong ex ante owner incentives to set prices of firm products or services below their short- term profit maximizing levels, since low prices signal low costs...... and as a consequence a higher sales value of the firm. Buyers take this signaling into consideration, but irrespective of their countermoves, the equilib- rium result may be a lowering of ex ante product prices, and an ex post market overvaluation of the firm. This model is utilized to suggest possible explanations...

  13. Identification of quantitative trait loci for fibrin clot phenotypes: the EuroCLOT study

    DEFF Research Database (Denmark)

    Williams, Frances M K; Carter, Angela M; Kato, Bernet

    2009-01-01

    OBJECTIVE: Fibrin makes up the structural basis of an occlusive arterial thrombus, and variability in fibrin phenotype relates to cardiovascular risk. The aims of the current study from the EU consortium EuroCLOT were to (1) determine the heritability of fibrin phenotypes and (2) identify QTLs as...

  14. Foreign Firms, Domestic Wages

    DEFF Research Database (Denmark)

    Malchow-Møller, Nikolaj; Schjerning, Bertel; R. Markusen, James

    2013-01-01

    Three types of theories have been used to explain the wage premium in foreign firms: the theories of heterogeneous workers, heterogeneous learning, and heterogeneous firms. We set up a model that explicitly encompasses two of these theories, and that can illustrate the third. This unifying framew...

  15. Location of New Firms

    DEFF Research Database (Denmark)

    Backman, Mikaela; Karlsson, Charlie

    2017-01-01

    In the entrepreneurship literature, it is generally assumed that an individual establishes a new firm in a location in which they have strong ties, normally in the municipality of residence or employment. We scrutinise this general assumption and show that firm location depends on individual...

  16. Utility of single-energy and dual-energy computed tomography in clot characterization: An in-vitro study.

    Science.gov (United States)

    Brinjikji, Waleed; Michalak, Gregory; Kadirvel, Ramanathan; Dai, Daying; Gilvarry, Michael; Duffy, Sharon; Kallmes, David F; McCollough, Cynthia; Leng, Shuai

    2017-06-01

    Background and purpose Because computed tomography (CT) is the most commonly used imaging modality for the evaluation of acute ischemic stroke patients, developing CT-based techniques for improving clot characterization could prove useful. The purpose of this in-vitro study was to determine which single-energy or dual-energy CT techniques provided optimum discrimination between red blood cell (RBC) and fibrin-rich clots. Materials and methods Seven clot types with varying fibrin and RBC densities were made (90% RBC, 99% RBC, 63% RBC, 36% RBC, 18% RBC and 0% RBC with high and low fibrin density) and their composition was verified histologically. Ten of each clot type were created and scanned with a second generation dual source scanner using three single (80 kV, 100 kV, 120 kV) and two dual-energy protocols (80/Sn 140 kV and 100/Sn 140 kV). A region of interest (ROI) was placed over each clot and mean attenuation was measured. Receiver operating characteristic curves were calculated at each energy level to determine the accuracy at differentiating RBC-rich clots from fibrin-rich clots. Results Clot attenuation increased with RBC content at all energy levels. Single-energy at 80 kV and 120 kV and dual-energy 80/Sn 140 kV protocols allowed for distinguishing between all clot types, with the exception of 36% RBC and 18% RBC. On receiver operating characteristic curve analysis, the 80/Sn 140 kV dual-energy protocol had the highest area under the curve for distinguishing between fibrin-rich and RBC-rich clots (area under the curve 0.99). Conclusions Dual-energy CT with 80/Sn 140 kV had the highest accuracy for differentiating RBC-rich and fibrin-rich in-vitro thrombi. Further studies are needed to study the utility of non-contrast dual-energy CT in thrombus characterization in acute ischemic stroke.

  17. Influence of Interleukin-1 Beta on Platelet-Poor Plasma Clot Formation: A Potential Impact on Early Bone Healing.

    Directory of Open Access Journals (Sweden)

    Xin Wang

    Full Text Available Hematoma quality (especially the fibrin matrix plays an important role in the bone healing process. Here, we investigated the effect of interleukin-1 beta (IL-1β on fibrin clot formation from platelet-poor plasma (PPP.Five-milliliter of rat whole-blood samples were collected from the hepatic portal vein. All blood samples were firstly standardized via a thrombelastograph (TEG, blood cell count, and the measurement of fibrinogen concentration. PPP was prepared by collecting the top two-fifths of the plasma after centrifugation under 400 × g for 10 min at 20°C. The effects of IL-1β cytokines on artificial fibrin clot formation from PPP solutions were determined by scanning electronic microscopy (SEM, confocal microscopy (CM, turbidity, and clot lysis assays.The lag time for protofibril formation was markedly shortened in the IL-1β treatment groups (243.8 ± 76.85 in the 50 pg/mL of IL-1β and 97.5 ± 19.36 in the 500 pg/mL of IL-1β compared to the control group without IL-1β (543.8 ± 205.8. Maximal turbidity was observed in the control group. IL-1β (500 pg/mL treatment significantly decreased fiber diameters resulting in smaller pore sizes and increased density of the fibrin clot structure formed from PPP (P < 0.05. The clot lysis assay revealed that 500 pg/mL IL-1β induced a lower susceptibility to dissolution due to the formation of thinner and denser fibers.IL-1β can significantly influence PPP fibrin clot structure, which may affect the early bone healing process.

  18. Protein C blood test

    Science.gov (United States)

    ... in the body that prevents blood clotting. A blood test can be done to see how much of ... Certain medicines can change blood test results. Tell your health care provider about all the medicines you take. Your provider will tell you if you need ...

  19. Protein S blood test

    Science.gov (United States)

    ... in your body that prevents blood clotting. A blood test can be done to see how much of ... Certain medicines can change blood test results: Tell your health care provider about all the medicines you take. Your provider will tell you if you need ...

  20. Milk clotting and proteolytic activity of enzyme preparation from ...

    African Journals Online (AJOL)

    Some microorganisms have the ability to produce enzymes that could clot milk and used as a substitute for calf rennet. Strains of lactic acid bacteria (LAB) could produce proteolytic enzymes that may have the potential to be used as a source of milk clotting enzyme (MCE). In the present study, LAB isolated from shrimp paste ...

  1. Foreign Firms, Domestic Wages

    DEFF Research Database (Denmark)

    Malchow-Møller, Nikolaj; Markusen, James R.; Schjerning, Bertel

    phenomenon. The second explanation builds on the heterogeneous-firm model of Melitz (2003) combined with on-the-job learning as in Markusen (2001). Productivity differences between firms are internalized by ex-ante homogeneous workers, so the wage premium is a pure learning phenomenon due to ex-post higher...... by developing a model that allows for two "pure" explanations for the wage premium. The first is a heterogenous-worker explanation along the lines of Yeaple (2005), where firms that select more scaleintensive technologies select ex-ante more productive workers. In this case, the wage premium is a pure selection...

  2. New polymorphic variants of human blood clotting factor IX

    Energy Technology Data Exchange (ETDEWEB)

    Surin, V.L.; Luk`yanenko, A.V.; Tagiev, A.F.; Smirnova, O.V. [Hematological Research Center, Moscow (Russian Federation); Plutalov, O.V.; Berlin, Yu.A. [Shemyakin Institute of Bioorganic Chemistry, Moscow (Russian Federation)

    1995-04-01

    The polymorphism of Alu-repeats, which are located in the introns of the human factor IX gene (copies 1-3), was studied. To identify polymorphic variants, direct sequencing of PCR products that contained appropriate repeats was used. In each case, 20 unrelated X chromosomes were studied. A polymorphic Dra I site was found near the 3{prime}-end of Alu copy 3 within the region of the polyA tract. A PCR-based testing system with internal control of restriction hydrolysis was suggested. Testing 81 unrelated X chromosomes revealed that the frequency of the polymorphic Dra I site is 0.23. Taq I polymorphism, which was revealed in Alu copy 4 of factor IX gene in our previous work, was found to be closely linked to Dra I polymorphism. Studies in linkage between different types of polymorphisms of the factor IX gene revealed the presence of a rare polymorphism in intron a that was located within the same minisatellite region as the known polymorphic insertion 50 bp/Dde I. However, the size of the insertion in our case was 26 bp. Only one polymorphic variant was found among over 150 unrelated X chromosomes derived from humans from Moscow and its vicinity. 10 refs., 4 figs., 1 tab.

  3. Evaluation of resuscitation fluids on endothelial glycocalyx, venular blood flow, and coagulation function after hemorrhagic shock in rats.

    Science.gov (United States)

    Torres, Luciana N; Sondeen, Jill L; Ji, Lisa; Dubick, Michael A; Torres Filho, Ivo

    2013-11-01

    Endothelial glycocalyx (EG) plays an essential role in endothelium integrity and may be compromised by hemorrhagic shock. The effects of currently available resuscitation fluids such as Hextend (HEX) or lactated Ringer's solution (LR) on vascular function and coagulation are not well understood. The aim of the present study was to compare the effects of fresh frozen plasma (FFP) with HEX or LR in their ability to repair EG structure, promote volume expansion, increase blood flow, and prevent coagulopathy. A total of 121 microvessels from cremaster muscle were studied in 32 anesthetized instrumented rats. After baseline systemic and microvascular measurements, 40% hemorrhage followed by resuscitation was performed, and measurements were repeated. Coagulation was evaluated using ROTEM to assay clot formation time, clotting time, firmness, strength, and lysis. Velocity and "platelet component" of strength were calculated. Fluorescein isothiocyanate or Texas Red bound to Dextrans was injected to estimate EG thickness in vivo. Respiratory rate, blood pH, base excess, and lactate returned to near-baseline levels in all treatments. Hemodilution caused by LR and HEX decreased firmness, prolonged clotting time, and lowered platelet counts. EG thickness in HEX- and LR-treated rats was 50% lower, and plasma syndecan 1 was 50% higher than sham and FFP groups. Blood flow and shear rate were restored in the HEX group. Resuscitation with FFP improved coagulation and blood flow. Our findings support the concept of cardiovascular and microvascular stabilization by infused FFP, in which the increase in microvascular perfusion associated with restored EG is essential for an optimal resuscitation strategy.

  4. Global Sourcing and Firm Selection

    DEFF Research Database (Denmark)

    Kohler, Wilhelm; Smolka, Marcel

    2014-01-01

    We analyze the sourcing strategies of firms active in the Spanish manufacturing sector. We show that firms that select strategies of vertical integration and of foreign sourcing ex post tend to have been more productive, ex ante, than other firms.......We analyze the sourcing strategies of firms active in the Spanish manufacturing sector. We show that firms that select strategies of vertical integration and of foreign sourcing ex post tend to have been more productive, ex ante, than other firms....

  5. Entrepreneurship and the Firm

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Klein, Peter G.

    While characteristically "Austrian" themes such as entrepreneurship, economic calculation, tacit knowledge and the temporal structure of capital are clearly relevant to the business firm, Austrian economists have said relatively little about management, organization and strategy. This work features...

  6. Firms, crowds, and innovation.

    Science.gov (United States)

    Felin, Teppo; Lakhani, Karim R; Tushman, Michael L

    2017-05-01

    The purpose of this article is to suggest a (preliminary) taxonomy and research agenda for the topic of "firms, crowds, and innovation" and to provide an introduction to the associated special issue. We specifically discuss how various crowd-related phenomena and practices-for example, crowdsourcing, crowdfunding, user innovation, and peer production-relate to theories of the firm, with particular attention on "sociality" in firms and markets. We first briefly review extant theories of the firm and then discuss three theoretical aspects of sociality related to crowds in the context of strategy, organizations, and innovation: (1) the functions of sociality (sociality as extension of rationality, sociality as sensing and signaling, sociality as matching and identity), (2) the forms of sociality (independent/aggregate and interacting/emergent forms of sociality), and (3) the failures of sociality (misattribution and misapplication). We conclude with an outline of future research directions and introduce the special issue papers and essays.

  7. Corruption and firm behavior

    OpenAIRE

    Sandra Sequeira; Simeon Djankov

    2013-01-01

    This paper investigates how corruption affects firrm behavior. Firms can engage in two types of corruption when seeking a public service: cost-reducing "collusive" corruption and cost increasing "coercive" corruption. Using an original and unusually rich dataset on bribe payments at ports matched to firrm-level data, we observe how firms respond to each type of corruption by adjusting their shipping and sourcing strategies. "Collusive" corruption is associated with higher usage of the corrupt...

  8. Financing firms in India

    OpenAIRE

    Allen, Franklin; Chakrabarti, Rajesh; De, Sankar; Qian, Jun; Qian, Meijun

    2006-01-01

    The authors examine the legal and business environments, financing channels, and governance mechanisms of various types of firms in India and compare them to those from other countries. Despite its English commonlaw origin, strong legal protection provided by the law, and a democratic government, corruption within India's legal system and government significantly weakens investor protection in practice. External financing of firms has been dominated by nonmarket sources of financing, while th...

  9. Transfusion packages for massively bleeding patients: the effect on clot formation and stability as evaluated by Thrombelastograph (TEG)

    DEFF Research Database (Denmark)

    Johansson, Per Ingemar; Bochsen, L.; Stensballe, J.

    2008-01-01

    We investigated the effect of administering a transfusion package encompassing 5 red blood cells (RBC), 5 fresh frozen plasma (FFP), and 2 platelet concentrates (PC) on clot formation and stability as evaluated by Thrombelastograph (TEG) in 10 patients presenting with massive bleeding. Blood...... was successful and 6 of these patients survived. The result indicates that an early balanced transfusion strategy maintains haemostatic competence in massively bleeding patients Udgivelsesdato: 2008/8...

  10. Discrepant fibrinolytic response in plasma and whole blood during experimental endotoxemia in healthy volunteers.

    Directory of Open Access Journals (Sweden)

    Sisse R Ostrowski

    Full Text Available Sepsis induces early activation of coagulation and fibrinolysis followed by late fibrinolytic shutdown and progressive endothelial damage. The aim of the present study was to investigate and compare the functional hemostatic response in whole blood and plasma during experimental human endotoxemia by the platelet function analyzer, Multiplate and by standard and modified thrombelastography (TEG.Prospective physiologic study of nine healthy male volunteers undergoing endotoxemia by means of a 4-hour infusion of E. coli lipopolysaccharide (LPS, 0.5 ng/kg/hour, with blood sampled at baseline and at 4 h and 6 h. Physiological and standard biochemical data and coagulation tests, TEG (whole blood: TEG, heparinase-TEG, Functional Fibrinogen; plasma: TEG±tissue-type plasminogen activator (tPA and Multiplate (TRAPtest, ADPtest, ASPItest, COLtest were recorded. Mixed models with Tukey post hoc tests and correlations were applied.Endotoxemia induced acute SIRS with increased HR, temperature, WBC, CRP and procalcitonin and decreased blood pressure. It also induced a hemostatic response with platelet consumption and reduced APTT while INR increased (all p<0.05. Platelet aggregation decreased (all tests, p<0.05, whereas TEG whole blood clot firmness increased (G, p = 0.05. Furthermore, during endotoxemia (4 h, whole blood fibrinolysis increased (clot lysis time (CLT, p<0.001 and Functional Fibrinogen clot strength decreased (p = 0.049. After endotoxemia (6 h, whole blood fibrinolysis was reduced (CLT, p<0.05. In contrast to findings in whole blood, the plasma fibrin clot became progressively more resistant towards tPA-induced fibrinolysis at both 4 h and 6 h (p<0.001.Endotoxemia induced a hemostatic response with reduced primary but enhanced secondary hemostasis, enhanced early fibrinolysis and fibrinogen consumption followed by downregulation of fibrinolysis, with a discrepant fibrinolytic response in plasma and whole blood. The finding that blood cells are

  11. Executive compensation and firm performance: Evidence from Indian firms

    Directory of Open Access Journals (Sweden)

    Mehul Raithatha

    2016-09-01

    Full Text Available The study examines the relationship between executive compensation and firm performance among Indian firms. The evidence suggests that firm performance measured by accounting, as well as market-based measures, significantly affects executive compensation. We also test for the presence of persistence in executive compensation by employing the system-generalised methods of moments (GMM estimator. We find significant persistence in executive compensation among the sample firms. Further, we report the absence of pay–performance relationship among the smaller sample firms and business group affiliated firms. Thus, our findings cast doubts over the performance-based executive compensation practices of Indian business group affiliated firms.

  12. Society for Pediatric Radiology John Caffey Award. MR appearance of blood and blood products: an in vitro study.

    Science.gov (United States)

    Cohen, M D; McGuire, W; Cory, D A; Smith, J A

    1986-06-01

    There are conflicting reports on the appearance of blood and blood clot as seen in the human body by MRI. This study was designed to show the in vitro MR signal intensity of human blood products in the fresh state and to evaluate the serial MRI changes that occur over time (2 weeks). T1 relaxation times were also measured. Anticoagulated whole blood, plasma, serum, white blood cell concentrates, platelet concentrates, lysed red cells, red cell concentrates, and blood clot were studied. The results show that plasma and serum have similar T1 values, as do lysed and intact erythrocytes. T1 of serum and plasma rose initially and then fell with the aging of the samples. T1 of red blood cells, clot, and packed red blood cells decreased for the first 48 hr and then remained constant for 7 days before increasing to the initial values by 2 weeks. Platelets and white blood cells had little influence on the MR image. However, temperature had a significant effect on T1 and signal intensity. In vivo clots are complex mixtures of whole clot, lysing clot, serum, and plasma influenced in various ways by the adjacent normal or diseased tissues. The chemical and physical properties of the mixture change constantly. Because of the clot's complex nature, determining the age of a hematoma from the appearance of clots on the MR image may not be possible.

  13. Collaborative Communities of Firms

    DEFF Research Database (Denmark)

    2011-01-01

    and developing strategic initiatives that aid the community as a whole. We discuss the facilitator role of the shared services provider, contrasting it with the coordinator role found in other multi-firm organizations, and we show how shared services providers function by describing three examples...... of collaborative communities of firms from different sectors: the U.S.-based Blade.org and two Denmark-based communities, the Kalundborg Industrial Symbiosis and MG50. Implications for the theory and practice of organization design are discussed.......Both small and medium-size entrepreneurial firms face liabilities such as resource scarcity and scale diseconomies, making it difficult for them to innovate on a continuous basis. In response, experimentation with new ways of organizing for innovation has increased. One successful result...

  14. Innovation in Family Firms

    DEFF Research Database (Denmark)

    Filser, Matthias; Brem, Alexander; Gast, Johanna

    2016-01-01

    , organizational culture and behaviour, resources, and innovation and strategy. Second, based on a thorough literature review the major research avenues are reflected. The comparison of the results of both analyses showed the following areas for future research on family firm innovation: members‘ individual human......Over the past decade, research on innovation in family firms has received growing attention by scholars and practitioners around the globe with a wide range of aspects explored within the current body of literature. Despite the constantly growing number of scientific publications, research lacks...... a comprehensive and critical review of past and present research achievements. First, conducting a bibliometric analysis with a focus on innovation in family firms, we identify five topical clusters that help to understand the foundations of recent findings: namely ownership and governance, structural settings...

  15. Modern Competitive Strategy Firm

    Directory of Open Access Journals (Sweden)

    František Bartes

    2010-01-01

    Full Text Available The article deals with problems of an ever increasing number of cases of successful application of old combat strategies in business practice. Nevertheless, the author refuses the so called “direct conflict“ of firms, when it is really fought for victory on the market. His approach is based on the philosophy of “victory without fight“, in other words – of achieving the aim without direct conflict with the rival firm.In the end he comes to the conclusion that combat philosophies are more and more often incorporated into classical approach of strategic firm control and become the integral part of philosophy of management. At the close happens to opinion that the one from basic factors absolutely necessary to creation such strategy at company, is necessary present so-called „creative intelligence“.

  16. Which Firms Use Measures?

    DEFF Research Database (Denmark)

    Rahbek Pedersen, Esben; Sudzina, Frantisek

    2012-01-01

    Purpose – The purpose of this paper is to outline the anatomy of firms which adopt comprehensive performance measurement (PM) systems in order to gain an understanding of how internal (organisational capabilities) and external (perceived environmental uncertainties) factors shape performance...... – This paper concludes that a limited number of internal and external factors have a significant influence on the adoption of PM systems. There is no consistent pattern, however, between the different sub-categories of organisational capabilities/perceived environmental uncertainties and PM adoption....... Originality/value – Much has been said about how changes in the environment and business structure require firms to develop new ways to measure performance. Less has been done to study whether firms adopting comprehensive PM systems actually match the characteristics of the “new economy”. The findings from...

  17. The Multinational Firm

    DEFF Research Database (Denmark)

    Morgan, Glenn; Hull Kristensen, Peer; Whitley, Richard

    In contrast to the traditional view of multinational firms as cohesive rational actors maximizing the use of resources across national boundaries, the contributors to this volume argue that they are complex social arenas where competing groups draw on resources from their own socially-embedded lo......In contrast to the traditional view of multinational firms as cohesive rational actors maximizing the use of resources across national boundaries, the contributors to this volume argue that they are complex social arenas where competing groups draw on resources from their own socially....... These processes occur at a number of levels which are explored in different empirical settings. Firstly, at the level of governance, multinational firms may develop conflicts between investors from different national contexts, for example between the arms-length orientation of Anglo-Saxon institutional investors...

  18. INTERNATIONALIZATION IN TAIWANESE FAMILY FIRMS

    OpenAIRE

    Hsiang-Lan Chen

    2011-01-01

    This paper studies the corporate internationalization decision of family firms and the effect of family ownership on internationalization. Using a panel data set of manufacturing firms listed on the Taiwan Stock Exchange during 2000–2007, the empirical results indicate that internationalization is positively and significantly related to family firms and family ownership. The findings suggest that, compared with non-family firms, family firms are more likely to internationalize. Additionally...

  19. Collaborative Communities of Firms

    DEFF Research Database (Denmark)

    Bøllingtoft, Anne; Müller, Sabine; Ulhøi, John Parm

    2011-01-01

    and developing strategic initiatives that aid the community as a whole. We discuss the facilitator role of the shared services provider, contrasting it with the coordinator role found in other multi-firm organizations, and we show how shared services providers function by describing three examples...... of collaborative communities of firms from different sectors: the U.S.-based Blade.org and two Denmark-based communities, the Kalundborg Industrial Symbiosis and MG50. Implications for the theory and practice of organization design are discussed....

  20. Servitization in Industrial Firms

    DEFF Research Database (Denmark)

    Hsuan, Juliana; Frandsen, Thomas; Raja, Jawwad

    themselves in relation to other companies in similar or related industries. In setting out a brief overview of the overall industrial service landscape in Denmark, the following is highlighted: - The extent to which Danish industrial firms are communicating service offerings through their websites...... analyzed in more detail, for example with regard to the types of services offered, company size, industry representation, turnover and earnings before interest and tax (EBIT). The analysis presented in this booklet may inspire Danish firms and help them, in their servitization journeys, to position...... - The relative frequency of different service categories and variation across industries - The characteristics of the analyzed companies in terms of size, turnover and EBIT...

  1. 14-Day thawed plasma retains clot enhancing properties and inhibits tPA-induced fibrinolysis.

    Science.gov (United States)

    Huebner, Benjamin R; Moore, Ernest E; Moore, Hunter B; Shepherd-Singh, Raymond; Sauaia, Angela; Stettler, Gregory R; Nunns, Geoffrey R; Silliman, Christopher C

    2017-11-01

    Plasma-first resuscitation attenuates trauma-induced coagulopathy (TIC); however, the logistics of plasma-first resuscitation require thawed plasma (TP) be readily available due to the obligatory thawing time of fresh frozen plasma (FFP). The current standard is storage of TP for up to 5 days at 4°C, based on factor levels at outdate, for use in patients at risk for TIC, but there remains a 2.2% outdated wastage rate. However, the multitude of plasma proteins in attenuating TIC remains unknown. We hypothesize that TP retains the ability to enhance clotting and reduce tPA-induced fibrinolysis at 14-day storage. FFP was thawed and stored at 4°C at the following intervals: 14, 10, 7, 5, 3, and 1-day prior to the experiment. Healthy volunteers underwent blood draws followed by 50% dilution with TP stored at previously mentioned intervals as well as FFP, normal saline (NS), albumin, and whole blood (WB) control. Samples underwent tPA-modified (75 ng/mL) thrombelastography (TEG) with analysis of R-time, angle, maximum amplitude (MA), and LY30. TEG properties did not change significantly over the thawed storage. 14-day TP retained the ability to inhibit tPA-induced hyperfibrinolysis (median LY30% 9.6%) similar to FFP (5.6%), WB (14.6%), and superior to albumin (59.3%) and NS (58.1%). 14-day TP also retained faster clot formation (median angle, 66.2°) and superior clot strength (MA, 61.5 mm) to albumin (34.8°, 21.6 mm) and NS (41.6°, 32.2 mm). TP plasma stored for 14 days retains clot-enhancing ability and resistance to clot degradation similar to FFP. A clinical trial is needed to validate these in vitro results. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Measuring Firm Performance

    DEFF Research Database (Denmark)

    Assaf, A. George; Josiassen, Alexander; Gillen, David

    2014-01-01

    Set in the airport industry, this paper measures firm performance using both desirable and bad outputs (i.e. airport delays). We first estimate a model that does not include the bad outputs and then a model that includes bad outputs. The results show important differences in the efficiency...

  3. Servitization in Industrial Firms

    DEFF Research Database (Denmark)

    Hsuan, Juliana; Frandsen, Thomas; Raja, Jawwad

    analyzed in more detail, for example with regard to the types of services offered, company size, industry representation, turnover and earnings before interest and tax (EBIT). The analysis presented in this booklet may inspire Danish firms and help them, in their servitization journeys, to position...

  4. Cyclicality and Firm Size in Private Firm Defaults

    DEFF Research Database (Denmark)

    Jensen, Thais Lærkholm; Lando, David; Medhat, Mamdouh

    2017-01-01

    The Basel II/III and CRD IV Accords reduce capital charges on bank loans to smaller firms by assuming that the default probabilities of smaller firms are less sensitive to macroeconomic cycles. We test this assumption in a default intensity framework using a large sample of bank loans to private...... Danish firms. We find that controlling only for size, the default probabilities of small firms are, in fact, less cyclical than the default probabilities of large firms. However, accounting for firm characteristics other than size, we find that the default probabilities of small firms are equally...... cyclical or even more cyclical than the default probabilities of large firms. These results hold using a multiplicative Cox model as well as an additive Aalen model with time-varying coefficients....

  5. Fibrin degradation products blood test

    Science.gov (United States)

    ... behind when clots dissolve in the blood. A blood test can be done to measure these products. ... Certain medicines can change blood test results. Tell your health care provider about all the medicines you take. Your provider will tell you if you need ...

  6. Firm-Specific Learning and the Nature of the Firm

    DEFF Research Database (Denmark)

    Knudsen, Thorbjørn

    2007-01-01

    This article discusses the limits of a purely transaction cost explanation of the existence of the firm by pointing to additional factors. A simple heuristic model shows that firm-specific learning effects can overcome the costs of monitoring employees, and explain the existence of the firm even ...

  7. Belgian firms visiting CERN

    CERN Multimedia

    FP Department

    2009-01-01

    25 – 26 MAY 2009 09.00 to 17.00 Monday 25 May 09.00 to 17.00 Tuesday 26 May Individual interviews will take place in technicians’ offices. The firms will contact relevant users/technicians but any user wishing to make contact with a particular firm is welcome to use the contact details which are available from each departmental secretariat or from the GS Department web pages here. List of Companies:Automation Services and Consulting BVBA Burrick NV, (PLC) Cissoid DB Engineering Design, Drafting & Services BVBA Entelec Control Systems GILLAM-Fei S.A. HPC ICSENSE IWT – Enterprise Europe Flanders Jema SA Mecasoft SA SA Polmans Rapid-Torc Resarm Engineering Plastics SA Sentera Europa NV SLC BVBA Stocker Industrie SA Technord Tecnubel Winlock BVBA For further information please contact Caroline Laignel (GS-DI 73722) or Karine Robert (GS-SEM-LS 74407).

  8. Determination of enoxaparin with rotational thrombelastometry using the prothrombinase-induced clotting time reagent.

    Science.gov (United States)

    Schaden, Eva; Schober, Andreas; Hacker, Stefan; Spiss, Christian; Chiari, Astrid; Kozek-Langenecker, Sibylle

    2010-04-01

    Drug monitoring of low molecular weight heparin is generally not recommended, but could be reasonable in critically ill patients, whose risk for bleeding or thrombosis shows a high interpatient variability. Anti-Xa assays are not available around the clock even in central hospitals, whereas rotational thrombelastometry (ROTEM) becomes increasingly used at the bedside. Prothrombinase-induced clotting time (PiCT) reagent allows determination of factor Xa-inhibition in plasma. The aim of our study was to evaluate enoxaparin determination in whole blood with the ROTEM using specific test modifications, including PiCT. After ethics committee's approval, citrated whole blood obtained from overall 16 healthy volunteers was incubated with enoxaparin at 16 different anti-Xa concentrations. Main endpoint was the clotting time (CT) in ROTEM representing initial activation of clot formation. CT was determined in the new PiCT-ROTEM test, in a low-tissue factor-activated modification (LowTF-ROTEM) as well as in the commercially available heparin-sensitive ROTEM assays (HEPTEM and INTEM). In the absence of enoxaparin, CT values were 168.6 +/- 6.1 s (PiCT-ROTEM), 247.3 +/- 18.6 s (LowTF-ROTEM), and -6.2 +/- 7.9 s (INTEM-HEPTEM). A linear dependency (P < 0.01) between anti-Xa concentration and CT was found for PiCT-ROTEM, LowTF-ROTEM, and for INTEM-HEPTEM with correlation coefficients of 0.93 for PiCT-ROTEM, 0.94 for LowTF-ROTEM, and 0.81 for INTEM-HEPTEM. This in-vitro experiment demonstrates a strong correlation between enoxaparin anti-Xa concentrations and specific ROTEM tests. These promising assays should be further evaluated for monitoring anticoagulation in high-risk patients in clinical studies.

  9. Interventional neuroradiology cases with intraprocedural clots: initial experience.

    Science.gov (United States)

    Gloss, David S; Alkire, Brian W

    2014-06-01

    Intraprocedural clot formation is rare but potentially serious complication of interventional neuroradiology procedures. We investigate if intraoperative monitoring (IOM) has utility to detect such clots. Intraprocedural clot formation is a rare but potentially serious complication of interventional neuroradiology procedures. Intraoperative monitoring detected nearly half of the included cases first. All of the included patients without improvement of the IOM changes were discharged home at best severely disabled. The study included patients with thromboembolic events during interventional neuroradiology cases at Barrow Neurologic Institute from 2006 to 2010, with prespecified outcomes. Electroneurodiagnostic recordings were reviewed. Twelve patients were included in this study. All showed changes in their IOM. Five showed a change in IOM recording before a change was seen on the angiogram. Two returned to baseline, four improved but not to baseline, and six did not improve at all. All six patients without IOM improvement were discharged at best severely disabled. Ten of the 12 patients with clots had a subarachnoid hemorrhage before treatment. Intraoperative monitoring recording may be a valuable tool in monitoring patients during endovascular treatment to identify intraprocedural thromboembolic events. Intraoperative monitoring may correlate with poor outcomes when the changed responses do not improve. These data might be important when determining how aggressive to be in treating intraprocedural clots. Electroneurodiagnostic seems to be particularly warranted in patients with subarachnoid hemorrhage before treatment. A larger study is needed to validate these findings.

  10. Connected Firms and Investor Myopia

    NARCIS (Netherlands)

    Ginglinger, Edith; Hébert, Camille; Renneboog, Luc

    2017-01-01

    Conglomerates, multinational corporations and business groups are non-exclusive forms of complex firms. Often organized as corporate networks, complex firms control a myriad of firms connected through ownership links. We investigate whether parent-subsidiary links within corporate networks enhance

  11. Web traffic and firm performance

    DEFF Research Database (Denmark)

    Farooq, Omar; Aguenaou, Samir

    2013-01-01

    -traffic on firm performance in civil law countries, firms with concentrated ownership, and firms with more intangible assets. All of these groups are characterized by higher agency problems. Our results, therefore, indicate that web-traffic can play a substitute for traditional governance mechanisms in the MENA...

  12. Clotting activation after transjugular intrahepatic portosystemic stent shunt.

    Science.gov (United States)

    Basili, S; Merli, M; Ferro, D; Lionetti, R; Rossi, E; Riggio, O; Valeriano, V; Capocaccia, L; Violi, F

    1999-05-01

    Aim of the study was to investigate the behaviour of clotting system in peripheral circulation of cirrhotic patients undergoing transjugular intrahepatic portosystemic stent shunt (TIPS). Clotting variables and endotoxemia were measured 48 h and 30 days after TIPS in patients randomised to receive heparin or not. Forty-eight hours after TIPS, a significant increase of prothrombin fragment F1+2 was observed; such increase was less evident in patients given heparin. Similar findings were observed for endotoxemia, which, however, was not affected by heparin treatment. Thirty days after TIPS procedure prothrombin fragment F1+2 and endotoxemia returned to baseline values independently of the treatment given. This study shows that TIPS is associated with an increase of clotting activation which might contribute to acute thrombosis observed after this procedure.

  13. Effect of Clotting Duration and Temperature on BDNF Measurement in Human Serum

    Science.gov (United States)

    Amadio, Patrizia; Sandrini, Leonardo; Tremoli, Elena

    2017-01-01

    Brain-derived neurothrophic factor (BDNF) is a neurotrophin expressed in different tissues and cells, including neurons, endothelial cells, leukocytes, megakaryocytes and platelets. Modifications of BDNF in plasma and/or in serum are associated with neurodegenerative and psychiatric disorders, cardiovascular diseases, metabolic syndrome and with mortality risk. Indeed, changes in blood levels of BDNF may reflect those of its tissue of origin and/or promote pathological dysfunctions. The measurement of BDNF amount in plasma or in serum has been characterized with particular attention in the impact of different anti-coagulants, clotting duration, temperature (≤21 °C) and delay in blood sample centrifugation as well as in stability of storage. However, the influences of normothermic conditions (37 °C) and of clotting duration on BDNF levels in human serum have not been investigated yet. Here, we showed that time and temperature during serum preparation could be taken into consideration to assess the association and/or impact of BDNF levels in the occurrence of pathological conditions. PMID:28914800

  14. Long-term cytokine and growth factor release from equine platelet-rich fibrin clots obtained with two different centrifugation protocols.

    Science.gov (United States)

    Jiménez-Aristizabal, Román F; López, Catalina; Álvarez, María E; Giraldo, Carlos; Prades, Marta; Carmona, Jorge U

    2017-09-01

    To compare the temporal release (over three weeks) of tumor necrosis factor alpha (TNF-α), interleukin 4 (IL-4), IL-1 receptor antagonist (IL-1ra), platelet-derived growth factor BB (PDGF-BB) and transforming growth factor beta-1 (TGF-β 1 ) from two platelet-rich fibrin (PRF) preparations from equine blood obtained at either 240g/8min or 416g/10min. Whole blood from 10 horses was used to obtain PRF clots by two different centrifugation protocols. After 1h of rest, PRF clots were deposited in wells with culture medium, which was changed at 6h, 24h and then every 48h to 21days. Cytokines and GFs were measured by ELISA at 1h (serum supernatants from PRF clots) and all time points of culture medium change. A negative control (plasma) and a positive control (blood lysate) were also included. There were no relevant differences between the two protocols for the temporal release of proteins. However, a significant (p=0.01) effect of time was noted. All cytokines were detected after 6h of PRF clot culture until day 21. GF were detected at 1h until day 21. The concentrations for these proteins diminished gradually over time. A highly significant (p=0.01) correlation was noticed between all the proteins evaluated. Leukocytes enmeshed in PRF clots were able to produce cytokines, TGF-β 1 and PDGF-BB. These findings demonstrate a paramount role of leukocytes in wound healing induced or modified by PRF clots in mammals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Innovation Management in Project-Based Firms

    NARCIS (Netherlands)

    F.P. Blindenbach

    2006-01-01

    textabstractProject-based firms have an organizational structure, capabilities and routines that clearly distinguish them from manufacturing firms. Some have claimed that these characteristics make project-based firms more innovative than, for instance, manufacturing firms, others argue the

  16. Danish firms visit CERN

    CERN Multimedia

    FP Department

    2011-01-01

    30 – 31 JANUARY 2012 09:00 to 17:00 Monday 30 January 09:00 to 17:00 Tuesday 31 January Individual interviews will take place in technicians’ offices. The firms will contact relevant users/technicians but any user wishing to make contact with a particular firm is welcome to use the contact details available from the secretariat of their department or from the GS Department web page. List of Companies: · Axcon APS · BB Electronics A/S · B.Rustfrit Stal A/S · CIM Industrial Systems A/S · Danfysik A/S · Develco A/S · Eletronic A/S · GPV Group · Innoware A/S · JLI Vision A/S · NECAS A/S· NKT Cables A/S · Noliac A/S · Prodan A/S · Röttger’s Vaerktoj A/S · Vengcon APS For further information please contact Claudia Bruggmann Furlan  GS-IS-LS 73312 or Caroline Laignel GS-DI 73722.

  17. Tests of Alternative Theories of Firm Growth.

    OpenAIRE

    Evans, David S

    1987-01-01

    This study examines the relationships among firm growth, firm size, and firm age for a sample of manufacturing firms between 1976 and 1982. Firm growth is found to decrease with firm age and firm size. These findings are robust to alternative assumptions concerning the effects of sample censoring and the functional form of the growth relationship. The inverse growth-age relationship is consistent with a theory of firm learning proposed by Boyan Jovanovic while the inverse growth-size relation...

  18. Blood

    Science.gov (United States)

    ... production of red blood cells, including: Iron deficiency anemia. Iron deficiency anemia is the most common type of anemia and ... inflammatory bowel disease are especially likely to have iron deficiency anemia. Anemia due to chronic disease. People with chronic ...

  19. [The influence of increased clotting reactions as shown by thrombosis formation in the immediate postoperative period on aortic valve prothesis (author's transl)].

    Science.gov (United States)

    Harke, H; Schwarze, E W; Stambolis, C; Bernhard, A

    1975-08-01

    Massive thrombosis formation on the valve periphery and on the top surface of the valve occurred in three patients (1,5%) in the immediate postoperative period with the Björk-Shiley valve in the aortic position. Between the third and sixth day these patients died of acute heart failure as a result of coronary artery displacement. Upon autopsy operative technical complications and postoperative infections were ruled out as the cause of death. What appears to be clinically important is an increase in clotting time in the immediate postoperative period which can be proven statistically. This increased clotting inclination was only found in these three patients and in one patient with frequent immediate postoperative peripheral embolic episodes. We therefore feel that early anticoagulation therapy is necessary. Heparin administration is preferred as it not only lowers the clotting ability of the blood but also the adhesive quality of the platelets.

  20. Thrombin and fibrinogen γ' impact clot structure by marked effects on intrafibrillar structure and protofibril packing.

    Science.gov (United States)

    Domingues, Marco M; Macrae, Fraser L; Duval, Cédric; McPherson, Helen R; Bridge, Katherine I; Ajjan, Ramzi A; Ridger, Victoria C; Connell, Simon D; Philippou, Helen; Ariëns, Robert A S

    2016-01-28

    Previous studies have shown effects of thrombin and fibrinogen γ' on clot structure. However, structural information was obtained using electron microscopy, which requires sample dehydration. Our aim was to investigate the role of thrombin and fibrinogen γ' in modulating fibrin structure under fully hydrated conditions. Fibrin fibers were studied using turbidimetry, atomic force microscopy, electron microscopy, and magnetic tweezers in purified and plasma solutions. Increased thrombin induced a pronounced decrease in average protofibril content per fiber, with a relatively minor decrease in fiber size, leading to the formation of less compact fiber structures. Atomic force microscopy under fully hydrated conditions confirmed that fiber diameter was only marginally decreased. Decreased protofibril content of the fibers produced by high thrombin resulted in weakened clot architecture as analyzed by magnetic tweezers in purified systems and by thromboelastometry in plasma and whole blood. Fibers produced with fibrinogen γ' showed reduced protofibril packing over a range of thrombin concentrations. High-magnification electron microscopy demonstrated reduced protofibril packing in γ' fibers and unraveling of fibers into separate protofibrils. Decreased protofibril packing was confirmed in plasma for high thrombin concentrations and fibrinogen-deficient plasma reconstituted with γ' fibrinogen. These findings demonstrate that, in fully hydrated conditions, thrombin and fibrinogen γ' have dramatic effects on protofibril content and that protein density within fibers correlates with strength of the fibrin network. We conclude that regulation of protofibril content of fibers is an important mechanism by which thrombin and fibrinogen γ' modulate fibrin clot structure and strength. © 2016 by The American Society of Hematology.

  1. Effect of acute exacerbations on circulating endothelial, clotting and fibrinolytic markers in COPD patients.

    Science.gov (United States)

    Polosa, Riccardo; Malerba, Mario; Cacciola, Rossella R; Morjaria, Jaymin B; Maugeri, Cinzia; Prosperini, Gaetano; Gullo, Raimondo; Spicuzza, Lucia; Radaeli, Alessandro; Di Maria, Giuseppe U

    2013-10-01

    Patients with chronic obstructive pulmonary disease (COPD) are prone to clinical exacerbations that are associated with increased airway inflammation, a potent pro-thrombotic stimulus. Limited information is available on the mechanisms underlying the putative alterations of the endothelial-coagulative system during acute exacerbations. The aim was to investigate whether the activation of the endothelial-coagulative system occurs in association with the acute inflammatory response of COPD exacerbation. We monitored the blood levels of surrogate markers of inflammation: interleukin-6 (IL-6); endothelium damage: von Willebrand's factor (vWF); clotting activation: D-dimer (D-D), and prothrombin fragment 1+2 (F1+2); fibrinolytic response: plasminogen activator inhibitor 1 (PAI-1), in COPD subjects, during hospital admission and after clinical resolution. In 30 COPD subjects, IL-6, vWF, D-D and F1+2 levels were elevated during exacerbation and decreased significantly at clinical stability (IL-6, p = 0.005; vWF, p < 0.001; D-D, p < 0.001; F1+2, p < 0.001). PAI-1 levels did not change at exacerbation compared to clinically stable situations. Positive correlations were observed between several of the markers measured. Elevation of IL-6, vWF, D-D and F1+2 levels during COPD exacerbations implies a strict association between acute inflammation, endothelial activation and clotting initiation. This was not associated with a change in PAI-1, implying an increase in the fibrinolytic response to inflammation. The pro-thrombotic nature of COPD exacerbations sustained by enhanced clotting activation appears to be mitigated by excessive fibrinolysis.

  2. The euglobulin clot lysis time to assess the impact of nanoparticles on fibrinolysis

    Energy Technology Data Exchange (ETDEWEB)

    Minet, Valentine, E-mail: valentine.minet@unamur.be; Alpan, Lutfiye; Mullier, François [University of Namur – UNamur, Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Nanosafety Center (NNC), NAmur Research Institute for Life Sciences NARILIS (Belgium); Toussaint, Olivier [Laboratory of Cellular Biochemistry and Biology (URBC) (Belgium); Lucas, Stéphane [University of Namur (UNamur), Research Centre for the Physics of Matter and Radiation (PMR-LARN), Namur Nanosafety Center NNC, NAmur Research Institute for Life Sciences NARILIS (Belgium); Dogné, Jean-Michel; Laloy, Julie, E-mail: julie.laloy@unamur.be [University of Namur – UNamur, Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Nanosafety Center (NNC), NAmur Research Institute for Life Sciences NARILIS (Belgium)

    2015-07-15

    Nanoparticles (NPs) are developed for many applications in various fields, including nanomedicine. The NPs used in nanomedicine may disturb homeostasis in blood. Secondary hemostasis (blood coagulation) and fibrinolysis are complex physiological processes regulated by activators and inhibitors. An imbalance of this system can either lead to the development of hemorrhages or thrombosis. No data are currently available on the impact of NPs on fibrinolysis. The objectives of this study are (1) to select a screening test to study ex vivo the impact of NPs on fibrinolysis and (2) to test NPs with different physicochemical properties. Euglobulin clot lysis time test was selected to screen the impact of some NPs on fibrinolysis using normal pooled plasma. A dose-dependent decrease in the lysis time was observed with silicon dioxide and silver NPs without disturbing the fibrin network. Carbon black, silicon carbide, and copper oxide did not affect the lysis time at the tested concentrations.

  3. Do Peer Firms Affect Firm Corporate Social Responsibility?

    OpenAIRE

    Shenggang Yang; Heng Ye; Qi Zhu

    2017-01-01

    Peer-firm strategies are a critical factor for corporate finance, and corporate social responsibility (CSR) is the main trend for evaluating the behavior of firms. On the basis of the connection between peer strategy and CSR, this paper explores the CSR strategies employed by a sample of Chinese firms during the 2008–2015 period. Our two main empirical findings are as follows. First, the CSR strategies of firms have a positive effect on their CSR behavior. Second, when there is the CSR gap be...

  4. Family Succession and Firm Performance: Evidence from Italian Family Firms

    OpenAIRE

    Marco Cucculelli; Giacinto Micucci

    2008-01-01

    This article contributes to the growing empirical literature on family firms by studying the impact of the founder�chief executive officer (CEO) succession in a sample of Italian firms. We contrast firms that continue to be managed within the family by the heirs to the founders with firms in which the management is passed on to outsiders. Family successions, that is, successions by the founder�s heirs, are further analyzed by assessing the impact of the sectoral intensity of competition o...

  5. 21 CFR 173.150 - Milk-clotting enzymes, microbial.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Milk-clotting enzymes, microbial. 173.150 Section 173.150 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... classified as follows: Class, Ascomycetes; order, Sphaeriales; family, Diaporthacesae; genus, Endothia...

  6. Effect of acute hyperglycemia on clotting time and relative plasma ...

    African Journals Online (AJOL)

    Menstruating females seem to bleed more when they ingest sugar or sugar containing substances. This study was carried out to determine the effect of acute hyperglycemia on clotting time and relative plasma viscosity during menstruation. Forty menstruating females from the St. Philomena School of Midwifery, Benin, ...

  7. Purification and characterization of a milk-clotting protease from ...

    African Journals Online (AJOL)

    user

    2011-02-28

    Feb 28, 2011 ... Desmazeaud M, Spinnler E (1997). Laits et produits laitiers. In «. Enzymes en agroalimentaires ». Ed. V. Larreta- Garde. Tech. et. Doc. Lavoisier. Esawy Mona A, Combet-blanc Yannick (2006). Immobilization of. Bacillus licheniformis 5A1 milk-clotting enzyme and characterization of its enzyme properties.

  8. Comparative Studies Of The Proteolytic And The Milk Clotting ...

    African Journals Online (AJOL)

    The use of enzymes as catalysts for industrial processes is becoming increasingly widespread, particularly in the food industry. The proteolytic and milk clotting activities of the crude latex of Calotropis procera, Carica papaya, and Musa paradisiaca were examined. The proteolytic activities of the crude latex were determined ...

  9. Identification and characterization of milk-clotting proteases ...

    African Journals Online (AJOL)

    Two strains of fungi were isolated and identified as Aspergillus tamarii and Penicillium pinophilum which showed good enzymatic activity on casein, 1933.33U and 1822, 21U, respectively. The search for milk clotting enzymes by fermentation at acid pH on culture medium containing whey and, after purification by molecular ...

  10. Identification and characterization of milk-clotting proteases ...

    African Journals Online (AJOL)

    SAM

    2014-03-12

    Mar 12, 2014 ... Biochem. Soc. Trans. 10:285. Hashem AM (2000). Purification and properities of a milk-clotting enzyme produced by Penicillium oxalicum. J. Bioresour. Technol. 75:219-222. Laemmli UK (1970). Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 227: 680-685.

  11. Firm Search for External Knowledge

    DEFF Research Database (Denmark)

    Sofka, Wolfgang; Grimpe, Christoph

    2012-01-01

    ignored the institutional context that provides or denies access to external knowledge at the country level. Combining institutional and knowledge search theory, we suggest that the market orientation of the institutional environment and the magnitude of institutional change influence when firms begin......The innovation performance of modern firms is increasingly determined by their ability to search and absorb external knowledge. However, after a certain threshold firms "oversearch" their environment and innovation performance declines. In this paper, we argue that prior literature has largely...... to experience the negative performance effects of oversearch. Based on a comprehensive sample of almost 8,000 firms from ten European countries, we find that institutions matter considerably for firms' search activity. Higher market orientation of institutions increases the effectiveness of firms' search...

  12. Board Effectiveness in Small Firms

    OpenAIRE

    Söderqvist, Anette; Wägar, Karolina

    2010-01-01

    Purpose: This study investigates boards of directors in small firms and explores the link between board effectiveness and the composition, roles and working styles of the boards. Design/methodology/approach: The study analyses data from a telephone survey of boards in 45 small firms. The survey included both the CEO and the chairperson of the board. Findings: The study identifies three groups of small firms: ‘paperboards’, ‘professional boards’, and ‘management lead’ boards. Results show that...

  13. Altered plasma fibrin clot properties in essential thrombocythemia.

    Science.gov (United States)

    Małecki, Rafał; Gacka, Małgorzata; Kuliszkiewicz-Janus, Małgorzata; Jakobsche-Policht, Urszula; Kwiatkowski, Jacek; Adamiec, Rajmund; Undas, Anetta

    2016-01-01

    Patients with increased thromboembolic risk tend to form denser fibrin clots which are relatively resistant to lysis. We sought to investigate whether essential thrombocythemia (ET) is associated with altered fibrin clot properties in plasma. Ex vivo plasma fibrin clot permeability coefficient (Ks), turbidimetry and clot lysis time (CLT) were measured in 43 consecutive patients with ET (platelet count from 245 to 991 × 10(3)/µL) and 50 control subjects matched for age, sex and comorbidities. Fibrinolysis proteins and inhibitors together with platelet activation markers were determined. Reduced Ks (-38%, p < 0.0001) and prolonged CLT (+34%, p < 0.0001) were observed in ET. The differences remained significant after adjustment for fibrinogen and platelet count. ET was associated with a slightly shorter lag phase (-5%, p = 0.01) and higher maximum absorbency of the turbidimetric curve (+6%, p < 0.001). The ET patients had higher plasma P-selectin by 193% (p < 0.00001) and platelet factor 4 (PF4) by 173% (p < 0.00001), with higher P-selectin observed in 19 (44%) patients with JAK-2 gene V617F mutation. Higher t-PA (+20%, p < 0.001), 23% higher plasminogen activator inhibitor-1, PAI-1 (+23%, p < 0.01) and unaltered thrombin-activatable fibrinolysis inhibitor, plasminogen and α2-antiplasmin activity were found in the ET group. Ks inversely correlated with fibrinogen, PF4 and C-reactive protein. CLT positively correlated only with PAI-1. Patients with ET display prothrombotic plasma fibrin clot phenotype including impaired fibrinolysis, which represents a new prothrombotic mechanism in this disease.

  14. Inside the Family Firm

    DEFF Research Database (Denmark)

    Bennedsen, Morten; Nielsen, Kasper; Pérez-González, Francisco

    2005-01-01

    show that a departing CEO's family characteristics have a strong predictive power in explaining CEO succession decisions: family CEOs are more frequently selected the larger the size of the family, the higher the ratio of male children and when the departing CEOs had only had one spouse. We......This paper uses a unique dataset from Denmark to investigate (1) the role of family characteristics in corporate decision making, and (2) the consequences of these decisions on firm performance. We focus on the decision to appoint either a family or an external chief executive officer (CEO). We...... then analyze the impact of family successions on performance. We overcome endogeneity and omitted variables problems of previous papers in the literature by using the gender of a departing CEO's first-born child as an instrumental variable (IV) for family successions. This is a plausible IV as male first...

  15. Belgian Firms Visit CERN

    CERN Multimedia

    2001-01-01

    Fifteen Belgian firms visited CERN last 2 and 3 April to present their know-how. Industrial sectors ranging from precision machining to electrical engineering and electronics were represented. And for the first time, companies from the Flemish and Brussels regions of the country joined their Walloon compatriots, who have come to CERN before. The visit was organised by Mr J.-M. Warêgne, economic and commercial attaché at the Belgian permanent mission for the French-speaking region, Mr J. Van de Vondel, his opposite number for the Flemish region, and Mrs E. Solowianiuk, economic and commercial counsellor at the Belgian permanent mission for the Brussels-Capital region.

  16. Experiences of Emerging Economy Firms

    DEFF Research Database (Denmark)

    Experiences of Emerging Economy Firms investigates the different elements of the experiences of emerging economy firms and sheds essential light on a large variety of aspects associated with their functioning in both home and host contexts. For example, firms must be able to overcome the liability...... of foreign and emerging issues when they expand their activities in various contexts, enter, exit, and re-enter overseas markets; they have to overcome institutional barriers, adapt the cultural challenges in foreign markets, undergo the impact of large multinational firms from developed economies...

  17. Scaling Behavior of Firm Growth

    Science.gov (United States)

    Stanley, Michael H. R.; Nunes Amaral, Luis A.; Buldyrev, Sergey V.; Havlin, Shlomo; Leschhorn, Heiko; Maass, Philipp; Salinger, Michael A.; Stanley, H. Eugene

    1996-03-01

    The theory of the firm is of considerable interest in economics. The standard microeconomic theory of the firm is largely a static model and has thus proved unsatisfactory for addressing inherently dynamic issues such as the growth of economies. In recent years, many have attempted to develop richer models that provide a more accurate representation of firm dynamics due to learning, innovative effort, and the development of organizational infrastructure. The validity of these new, inherently dynamic theories depends on their consistency with the statistical properties of firm growth, e.g. the relationship between growth rates and firm size. Using the Compustat database over the time period 1975-1991, we find: (i) the distribution of annual growth rates for firms with approximately the same sales displays an exponential form with the logarithm of growth rate, and (ii) the fluctuations in the growth rates --- measured by the width of this distribution --- scale as a power law with the firm sales. We place these findings of scaling behavior in the context of conventional economics by considering firm growth dynamics with temporal correlations and also, by considering a hierarchical organization of the departments of a firm.

  18. Patenting activities and firm performance : Does firm size matter?

    NARCIS (Netherlands)

    Andries, P.; Faems, D.L.M.

    2013-01-01

    Whereas prior research has provided valuable insights into the willingness of small and medium-sized enterprises (SMEs) and large firms to engage in patenting, a comparison of the performance implications of patenting activities across small and large firms is still lacking. This gap is important

  19. Firm Traits and Web Based Disclosures in Top Nigerian Firms

    Directory of Open Access Journals (Sweden)

    Bello Ayuba

    2016-02-01

    Full Text Available The use of the internet as a medium of dissemination of information to stakeholders is increasingly gaining grounds. This study extends existing literature on web disclosures by investigating the characteristics that predict the extent of web-based disclosures. In this study, corporate websites of top Nigerian firms are used as sources of data, while a regression analysis is employed to examine the extent of prediction. Results indicate that the firm size and industry type are significant determinants of web disclosures. However, other firm traits such as ownership dispersion and financial performance do not significantly explain the extent of internet disclosures. The study recommends that a regulatory template for corporate web disclosures be put in place by government regardless of the size or industry classification of the firm. This is with a view to considerably reduce agency conflicts arising from information asymmetry in publicly listed firms in Nigeria.

  20. Evaluation of Fibrin Clot Attachment on Titanium Laser-Conditioned Surface Using Scanning Electron Microscopy.

    Science.gov (United States)

    Sinjari, Bruna; Traini, Tonino; Caputi, Sergio; Mortellaro, Carmen; Scarano, Antonio

    2018-03-22

    The study aimed to evaluate the effects of different titanium surface treatments on blood clot extension (bce). A total of 54 titanium disks with machined surface (M), laser-conditioned surface (L), and grit-blasted surface (S) were used in the present study. The surface characteristics such as contact angles and the microroughness were determined on each group (n = 4). To evaluate the bce, 0.1 mL of human blood was dropped onto the surface of each specimen and left for 7 minutes at room temperature. After fixation, dehydration, and gold sputtering treatments, the specimens were observed under scanning electron microscope. The bce values were expressed as percentage of specimen surface covered by blood clot. The surface roughness (Ra ± standard deviation [SD]) was 0.75 ± 0.02 μm for M, 0.25 ± 0.02 μm for L, and 1.30 ± 0.03 μm for S. The contact angles measured in static conditions (WCA ± SD) were 71 ± 5.4° for M, 107 ± 6.6° for L, and 91 ± 7.2° for S. Regarding the bce (bce ± SD) of M samples (65.5 ± 4.3%) was statistically lower compared with both L (83.4 ± 5.1%) and S samples (72.4 ± 4.7%) (P < 0.05). Meanwhile, the L group showed the higher bce value. The present results suggest that the laser-conditioned surface may increase the wettability and bce.

  1. Whom do new firms hire?

    DEFF Research Database (Denmark)

    Dahl, Michael S.; Klepper, Steven

    2015-01-01

    Using the matched employer-employee data set for Denmark and information on the founders of new firms, we analyze the hiring choices of all new firms that entered from 2003 to 2010. We develop a theoretical model in which the quality of a firm’s employees determines its average cost, a firm’s pro...

  2. Quality control in audit firm

    OpenAIRE

    Dostálová, Milena

    2008-01-01

    Thesis deals with the quality control of audit firms in accordance with international regulations. Defining the requirements for quality based on the Code of Ethics and the International quality standard ISQC1. Part of this work is the practical demonstration of ISQC1 in the smaller audit firm. For comparison, there is a description of quality control in the U.S.

  3. Dividend Policy of German Firms

    NARCIS (Netherlands)

    Goergen, M.; Renneboog, L.D.R.; Correia Da Silva, L.

    2004-01-01

    German firms pay out a lower proportion of their cash flows than UK and US firms.However, on a published profits basis, the pattern is reversed.Company law provisions and accounting policies account for these conflicting results.A partial adjustment model is used to estimate the implicit target

  4. Do some Firms Persistently Outperform?

    NARCIS (Netherlands)

    Capasso, M.|info:eu-repo/dai/nl/314016627; Cefis, E.|info:eu-repo/dai/nl/274516233; Frenken, K.|info:eu-repo/dai/nl/207145253

    2009-01-01

    This study analyses persistence in growth rates of the entire population of Dutch manufacturing firms. Previous literature on firm growth rates shows that extreme growth events are likely to be negatively correlated over time. A rebound effect following an extreme growth event questions the

  5. Do some firms persistently outperform?

    NARCIS (Netherlands)

    Capasso, M.; Cefis, E.; Frenken, K.

    2009-01-01

    This study analyses persistence in growth rates of the entire population of Dutch manufacturing firms. Previous literature on firm growth rates shows that extreme growth events are likely to be negatively correlated over time. A rebound effect following an extreme growth event questions the

  6. Competitive Advantage of Interconnected Firms

    DEFF Research Database (Denmark)

    Nell, Phillip Christopher; Andersson, Ulf

    We model the complex interplay between firm-level variables, notably capabilities and performance, and relationship-level variables: relationship-specific assets and network context. We test how the network context of individual exchange relationships as well as firm-level capabilities jointly af...

  7. Social security and firm performance

    DEFF Research Database (Denmark)

    Lee, Sangheon; Torm, Nina

    2017-01-01

    security coverage by 10 per cent experience a revenue gain of 1.4-2.0 per cent per worker and a profit gain of up to 1.8 per cent, depending on the survival time of the firm. However, given the time lag between 'investment' (in social security contributions) and returns (enhanced firm performance...

  8. Does internationalization foster firm performance?

    NARCIS (Netherlands)

    van den Berg, Marcel

    2014-01-01

    The research in this dissertation concerns the impact of internationalization of business activities on several dimensions of firm performance. We show that the productivity ranking by trade status of Dutch manufacturing firms in increasing order of productivity is: non-traders, importers, exporters

  9. Bank Relationship and Firm Profitability

    NARCIS (Netherlands)

    Degryse, H.A.; Ongena, S.

    2000-01-01

    This paper examines how bank relationships affect firm performance. An empirical implication of recent theoretical models is that firms maintaining multiple bank relationships are less profitable than their single-bank peers. We investigate this empirical implication using a data set containing

  10. Relationship Lending and Firm Innovativeness

    NARCIS (Netherlands)

    Giannetti, C.

    2009-01-01

    This study investigates the effects of relationship lending on firm innovativeness using a panel of Italian manufacturing firms. In order to disentangle the impact of bank ties on the discovery phase from that in the introduction phase of new technologies, the analysis proceeds in two steps,

  11. Technological Capability and Firm Performance

    Directory of Open Access Journals (Sweden)

    Fernanda Maciel Reichert

    2014-08-01

    Full Text Available This research aims to investigate the relationship between investments in technological capability and economic performance in Brazilian firms. Based on economic development theory and on developed countries history, it is assumed that this relationship is positive. Through key indicators, 133 Brazilian firms have been analyzed. Given the economic circumstances of an emerging economy, which the majority of businesses are primarily based on low and medium-low-technology industries, it is not possible to affirm the existence of a positive relation between technological capability and firm performance. There are other elements that allow firms to achieve such results. Firms of lower technological intensity industries performed above average in the economic performance indicators, adversely, they invested below average in technological capability. These findings do not diminish the merit of firms’ and country’s success. They in fact confirm a historical tradition of a country that concentrates its efforts on basic industries.

  12. The formation and breakdown of structured clots from whole milk during gastric digestion.

    Science.gov (United States)

    Ye, Aiqian; Cui, Jian; Dalgleish, Douglas; Singh, Harjinder

    2016-10-12

    The behaviour of milk fat globules in the coagula of unheated and heated (90 °C for 20 min) whole milk during gastric digestion was investigated using a human gastric simulator. Structured protein clots were formed by a coagulation process that was driven by the action of the milk-clotting enzyme, pepsin, on the protein fraction of the whole milk. The fat globules in the milk appeared to be embedded in the clots as they formed. After clot formation, the different structures of the clots formed with unheated and heated whole milk led to different rates of protein hydrolysis by pepsin and resulted in the release of fat globules from the clots into the digesta; the release of fat globules was faster in the clots from the heated whole milk. Comparison of the rates of fat globule release from the clots and the rates of the reduction in fat-free matter in the clots showed that the release of fat globules from the clots from both unheated and heated milk was linearly dependent on the breakdown of the protein in the clots. Coalescence of fat globules appeared to occur in the gastric digesta and also within the protein.

  13. Risk management in acute pulmonary embolism: correlation between right heart dysfunction, pulmonary clots distribution, biomarkers and prognosis

    Directory of Open Access Journals (Sweden)

    Luca Masotti

    2013-05-01

    Full Text Available BACKGROUND Right heart dysfunction (RHD is related to adverse outcomes in acute pulmonary embolism (PE. AIM OF THE STUDY To evaluate the relation between RHD, pulmonary clots distribution and biomarkers and prognosis of patients with PE. METHODS We analysed echocardiographic data of 70 patients with diagnosis of PE confirmed by pulmonary computer tomography, hCT. We considered the enddiastolic right/left ventricles ratio > 1 as index of RHD; echocardiographic data were compared with clots distribution in pulmonary vascular tree such as hCT findings and biomarkers. For each patient we calculated the shock index (heart rate/systolic blood pressure ratio, shock defined as ratio ≥ 1. RESULTS Hospital mortality was 8.5%. Mean age of dead patients was significantly higher compared to alive (85.67 vs 71.57 years, p < 0.05. 41% of patients revealed unilateral PE, 59% had bilateral. In 10% of patients main pulmonary artery was interested by clot, 48% of patients had involved one of the main branches, 90% had involved at least one of the lobar branches, 59% one of segmental branches of pulmonary arteries. 52% of patients had RHD. Mortality in RHD patients was 14.8% vs 8% in no RHD, p < 0.05. Mean values of troponin I and D-dimer were significantly higher in RHD patients. Shock index was ≥ 1 in 37.5% of RHD and 20% in no RHD. RHD patients showed significantly higher involvement of main pulmonary artery and its branches and higher bilateral involvement. CONCLUSIONS RHD is related to proximal and bilateral pulmonary clots distribution and troponin I and D-dimer values and poorer prognosis.

  14. Thromboelastography on plasma reveals delayed clot formation and accelerated clot lyses in HIV-1 infected persons compared with healthy controls

    DEFF Research Database (Denmark)

    Rönsholt, Frederikke Falkencrone; Gerstoft, Jan; Ullum, Henrik

    2015-01-01

    BACKGROUND: Thromboembolic events among HIV infected persons are a recognized clinical problem but the underlying mechanisms are poorly understood. To assess whether coagulation and fibrinolysis differ between long-term treated HIV infected individuals (HIV+) and healthy controls (CON), we......PA), and measured levels of C-reactive protein, thrombomodulin, syndecan-1, sVE-cadherin, soluble CD40 ligand (sCD40L), adrenaline and noradrenaline. RESULTS: Compared to CON, HIV+ had delayed clot formation (reaction (R)-time 14.2 min. vs. 11.2 min., p = 0.0004) and reduced clot formation rapidity (angle 22.6° vs...... HIV infected persons displays a hypocoagulable profile with reduced fibrinolytic resistance as compared to healthy controls....

  15. Firm Sustainability Performance Index Modeling

    Directory of Open Access Journals (Sweden)

    Che Wan Jasimah Bt Wan Mohamed Radzi

    2015-12-01

    Full Text Available The main objective of this paper is to bring a model for firm sustainability performance index by applying both classical and Bayesian structural equation modeling (parametric and semi-parametric modeling. Both techniques are considered to the research data collected based on a survey directed to the China, Taiwan, and Malaysia food manufacturing industry. For estimating firm sustainability performance index we consider three main indicators include knowledge management, organizational learning, and business strategy. Based on the both Bayesian and classical methodology, we confirmed that knowledge management and business strategy have significant impact on firm sustainability performance index.

  16. Effect of solvent/detergent-treated pooled plasma on fibrinolysis in reconstituted whole blood.

    Science.gov (United States)

    Saadah, Nicholas H; van der Meer, Pieter F; Brinkman, Herm Jan M; de Korte, Dirk; Bontekoe, Ido J; Korsten, Herbert H; Middelburg, Rutger A; van der Bom, Johanna G; Schipperus, Martin R

    2017-10-01

    Hyperfibrinolysis has been observed in patients heavily transfused with solvent/detergent-treated pooled plasma (S/D plasma). We compared coagulation and fibrinolytic variables in blood containing S/D plasma with blood containing fresh-frozen plasma (FFP), with and without α2-antiplasmin or tranexamic acid (TXA) supplementation. Whole blood samples were reconstituted from red blood cells, platelet (PLT) concentrates, and varying mixtures of FFP and S/D plasma. Hematocrit and PLT count of reconstituted whole blood samples were varied. For a subset of runs, α2-antiplasmin or TXA was added to S/D plasma whole blood samples. Thromboelastography (TEG) analysis was performed to assess 50% clot lysis time (CLT 50% ), maximum amplitude (MA), and initial clotting time (R-time). The change in CLT 50% of whole blood as the plasma compartment transitions from FFP to S/D plasma was -52% (95% confidence interval [CI], -60% to -45%; p plasma in whole blood. α2-Antiplasmin and TXA restored clot lysis time in S/D plasma whole blood. Whole blood with S/D plasma has shorter clot lysis times in vitro compared to whole blood with FFP. α2-Antiplasmin and TXA restore clot lysis time of S/D plasma whole blood to that of FFP whole blood. Clinicians should be aware of the decreased clot lysis time associated with S/D plasma transfusion. © 2017 AABB.

  17. Prospective randomized study evaluating the effects of PerClot® (Polysaccharide Hemostatic System) application in patients with high bleeding risk undergoing cardiac rhythm device implantation.

    Science.gov (United States)

    Tscholl, Verena; Spann, Felicitas; Moses, Jane; Nagel, Patrick; Bellmann, Barbara; Biewener, Sebastian; Amtenbrink, Marie; Stroux, Andrea; Rillig, Andreas; Landmesser, Ulf; Roser, Mattias

    2017-12-01

    Thus far, the topic hemostatic agent PerClot® is used for surgical procedures. Data about the use of PerClot® for cardiac-rhythm-devices (CRD) implantation are missing. The aim of this study was to evaluate the safety and efficacy of PerClot® in patients with high bleeding risk. In this prospective randomized study we planned to include 150 patients admitted for CRD-Implantation receiving anticoagulation and/or dual-antiplatelet-therapy. Participants were randomized to receive PerClot® versus standard-of-care. The primary endpoint was the incidence of pocket hematoma. Safety endpoint was pocket infection. After a planned safety-interim-analysis the study was terminated early because of safety concerns. 51 patients were included. The two groups were comparable with regard to age (73±11years vs. 74±10years; p=0.71), CHA 2 DS 2 VASc (3.6±1.5 vs. 4.0±1.5; p=0.27) and HASBLED-Score (2.4±1.1 vs. 2.5±1.0; p=0.98), CRD or procedure type, anticoagulant or anti-platelet therapy. The use of PerClot® resulted in a higher incidence of postoperative fever (7 (28%) vs. 0 (0%); p=0.004), higher C-Reactive Protein (66.1±50.5mg/l vs. 25.9±22.5mg/l; p=0.002); and higher postoperative white blood cell count (13.5±4.3/nl vs. 8.8±2.6/nl; p<0.001). Hematoma formation did not differ significantly (p=0.14). Reoperation was not necessary in any patient. This first randomized controlled study for the topical use of the hemostatic agent PerClot® in CRD implantation was terminated early by the safety monitoring board because of an augmented rate of fever and inflammatory markers in the PerClot® group. The addition of PerClot® does not suggest a benefit with regard to the frequency of pocket hematoma. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. PARTIAL PURIFICATION OF MILK-CLOTTING ENZYME FROM THE SEEDS OF MORINGA OLEIFERA

    Directory of Open Access Journals (Sweden)

    Amna E. Tajalsir

    2014-08-01

    Full Text Available The aim of the present study was to search for milk clotting substitute from different parts (flowers, seeds, stem, leaves, ripe and unripe fruits of Moringa oleifera. The samples were blended and extracted using different types of extracting solutions. The most reliable, quick and efficient enzyme extracting solution was found to be 5% NaCl in 100 mM sodium acetate buffer, pH 5.0, which was used throughout the study. The milk clotting activity was only observed in the seeds extract while the other parts were either deficient or has very low milk clotting activity. Thus, the moringa seeds were used as source of milk clotting enzyme. The extracted proteins were fractionated with ammonium sulfate at concentration of 20, 30, 40, 50 and 60 %. Highest milk clotting activity was observed in the 20 % fraction. This fraction was assumed to contain the clotting enzymes and characterized for its heating stability (30 – 90°C and optimum temperature (30 – 90°C. The results demonstrated that moringa seeds milk clotting enzyme is stable up to 50°C with an optimum milk clotting activity of 70°C. The high ratio of milk-clotting to proteolytic activity of the partially purified enzyme indicates the potential of this enzyme as suitable rennet substitute in dairy industry. However, further study is needed to completely purify and characterize this promising milk clotting enzyme from moringa seeds.

  19. The Role of Firm Ownership on Internationalization

    DEFF Research Database (Denmark)

    Hobdari, Bersant; Gregoric, Aleksandra; Sinani, Evis

    2011-01-01

    This paper investigates how different types of owners influence the extent of firm internationalization, measured by the share of firm exports in total sales. The results of the analysis carried out using firm level data of Estonian and Slovenian firms, show that the firms under the control of th...... in internationalization process. Finally, high market share also leads to increased internationalization through exports as firms seek to expand in foreign markets after having dominated the domestic ones....

  20. Consumer Networks and Firm Reputation

    DEFF Research Database (Denmark)

    Huck, Steffen; Lünser, Gabriele K.; Tyran, Jean-Robert

    Arguing that consumers are the carriers of firms' reputations, we examine the role of consumer networks for trust in markets that suffer from moral hazard. When consumers are embedded in a network, they can exchange information with their neighbours about their private experiences with different...... sellers. We find that such information exchange fosters firms' incentives for reputation building and, thus, enhances trust and efficiency in markets. This efficiency-enhancing effect is already achieved with a rather low level of network density...

  1. Experiences of Emerging Economy Firms

    DEFF Research Database (Denmark)

    of foreign and emerging issues when they expand their activities in various contexts, enter, exit, and re-enter overseas markets; they have to overcome institutional barriers, adapt the cultural challenges in foreign markets, undergo the impact of large multinational firms from developed economies...... and experience the impact of home institutions and government policies. This ground breaking and illuminating title presents issues of theoretical and practical significance, thus challenging existing paradigms of firm internationalization....

  2. The Survival of Tuscan Firms

    OpenAIRE

    Filippo Randelli; Giorgio Ricchiuti

    2015-01-01

    In this paper we analyze the survival probability of firms in Tuscany (Italy) in the first decade of the $21^{st}$ century. Using the Official Register of Firms, held by Unioncamere Toscany, we build a panel for the period 1998-2010. Taking into account both individual and context variables, we find that a higher institutional complexity and a lower population density have a positive and significant effect on probability to survive. Moreover, both MAR and Jacob externalities have a nonlinear ...

  3. Travail et pouvoir d’agir d’Yves Clot

    Directory of Open Access Journals (Sweden)

    Jacques Leplat

    2008-11-01

    Full Text Available Yves Clot est titulaire de la Chaire de psychologie du travail du Conservatoire National des Arts et Métiers (CNAM au sein duquel il dirige l’équipe de clinique de l’activité. Cet ouvrage est le second qu’il publie dans cette collection, le premier « La fonction psychologique du travail » est paru en 1999. Entre les deux s’inscrivent un grand nombre de publications, dont beaucoup avec d’autres chercheurs, comme on pourra le constater en consultant la bibliographie de ce livre. Ce denier réun...

  4. Pengaruh Family Control, Firm Size, Firm Risk, Dan Firm Life Cycle Terhadap Profitabilitas Dan Nilai Perusahaan Sektor Industri Barang Konsumsi

    OpenAIRE

    Servin, Servin

    2014-01-01

    This study aims to examine the effect of family control, firm size, firm risk, and firm lifecycle towards profitability and firm's value. Sampels were taken from 27 consumer goodscompanies, listed in Indonesia Stock Exchange, ranging from 2010 – 2012. The hypotheseswere tested using multiple regression analysis. In this study, profitability was measured byROA (Return on Asset) and firm's value was measured by Tobin's q. The result were, familycontrol and life cycle stage-growth had negative i...

  5. Biological variation in tPA-induced plasma clot lysis time.

    Science.gov (United States)

    Talens, Simone; Malfliet, Joyce J M C; Rudež, Goran; Spronk, Henri M H; Janssen, Nicole A H; Meijer, Piet; Kluft, Cornelis; de Maat, Moniek P M; Rijken, Dingeman C

    2012-10-01

    Hypofibrinolysis is a risk factor for venous and arterial thrombosis, and can be assessed by using a turbidimetric tPA-induced clot lysis time (CLT) assay. Biological variation in clot lysis time may affect the interpretation and usefulness of CLT as a risk factor for thrombosis. Sufficient information about assay variation and biological variation in CLT is not yet available. Thus, this study aimed to determine the analytical, within-subject and between-subject variation in CLT. We collected blood samples from 40 healthy individuals throughout a period of one year (average 11.8 visits) and determined the CLT of each plasma sample in duplicate. The mean (± SD) CLT was 83.8 (± 11.1) minutes. The coefficients of variation for total variation, analytical variation, within-subject variation and between-subject variation were 13.4%, 2.6%, 8.2% and 10.2%, respectively. One measurement can estimate the CLT that does not deviate more than 20% from its true value. The contribution of analytical variation to the within-subject variation was 5.0%, the index of individuality was 0.84 and the reference change value was 23.8%. The CLT was longer in the morning compared to the afternoon and was slightly longer in older individuals (> 40 years) compared to younger (≤40 years) individuals. There was no seasonal variation in CLT and no association with air pollution. CLT correlated weakly with fibrinogen, C-reactive protein, prothrombin time and thrombin generation. This study provides insight into the biological variation of CLT, which can be used in future studies testing CLT as a potential risk factor for thrombosis.

  6. Power Laws in Firm Productivity

    Science.gov (United States)

    Mizuno, T.; Ishikawa, A.; Fujimoto, S.; Watanabe, T.

    We estimate firm productivity for about 3.2 million firms from30 countries. We find that the distribution of firm productivity in each country, which is measured by total factor productivity (TFP), has a power law upper tail. However, the power law exponent of a TFP distribution in a country tends to be greater than that of a sales distribution in that country, indicating that the upper tail of a TFP distribution is less heavy compared to that of a sales distribution. We also find that the power law exponent of a TFP distribution tends to be greater than the power law exponents associated with the number of workers or tangible fixed assets. Given the idea that the sales of a firm is determined by the amount of various inputs employed by the firm (i.e., ``production function'' in the terminology of economics), these results suggest that the heavy tail of a sales distribution in a country comes not from the tail of a TFP distribution, but from the tail of the distribution of the number of workers or tangible fixed assets.

  7. Whole Blood and Hextend: Bookends of Modern Tactical Combat Casualty Care Field Resuscitation and Starting Point For Multi-functional Resuscitation Fluid Development.

    Science.gov (United States)

    Sheppard, Forest R; Mitchell, Thomas A; Macko, Antoni R; Fryer, Darren M; Schaub, Leasha J; Ozuna, Kassandra M; Glaser, Jacob J

    2017-12-20

    Hemorrhage is the leading cause of preventable death in traumatically injured civilian and military populations. Pre-hospital resuscitation largely relies on crystalloid and colloid intra-vascular expansion, as whole blood and component blood therapy are logistically arduous. In this experiment, we evaluated the bookends of Tactical Combat Casualty Care Guidelines recommendations of pre-hospital resuscitation with Hextend and whole blood in a controlled hemorrhagic shock model within non-human primates, as means of a multi-functional resuscitative fluid development. In the non-human primate, a poly-trauma model was utilized, consisting of a musculoskeletal injury (femur fracture), soft tissue injury (15cm laparotomy), and controlled hemorrhage to a mean arterial pressure of 20 mmHg, demarcating the beginning of the shock period. Animals were randomized to pre-hospital interventions of whole blood or Hextend at T=0 minutes, and at T=90 minutes definitive surgical interventions and balanced sanguineous damage control resuscitation could be implemented. All animals were euthanized at T=480 minutes. Data are expressed as mean±SEM; significance, p<0.05. No significant differences in survival, 83% vs. 100%, p=0.3), tissue perfusion (EtCO2 & StO2) or endpoints of resuscitation (base deficit, lactate, pH) between Hextend and whole blood were identified. Secondly, whole blood compared to Hextend demonstrated significantly earlier normalization of clot formation time, maximal clot firmness, and α angle. A future multi-functional resuscitative fluid including an asanguineous, oncotic, non-oxygen carrying component to facilitate intra-vascular volume expansion and a component with synthetic coagulation factors and fibrinogen to deter coagulopathy may show equivalence to whole blood. Translational animal model LEVEL OF EVIDENCE: N/A.

  8. Impact of export destinations on firm performance

    OpenAIRE

    Cebeci, Tolga

    2014-01-01

    This paper evaluates the role of export destinations on productivity, employment, and wages of Turkish firms by comparing the performance of firms that export to low-income destinations and high-income destinations with firms that do not export. A combination of propensity score matching and difference-in-differences methods are employed on a rich set of firm observables, including sector,...

  9. Foreign Entry and Heterogeneous Growth of Firms

    DEFF Research Database (Denmark)

    Deng, Paul Duo; Jefferson, Gary H.

    We adopt the framework of Schumpeterian creative destruction formalized by Aghion et al. (2009) to analyze the impact of foreign entry on the productivity growth of domestic firms. In the face of foreign entry, domestic firms exhibit heterogeneous patterns of growth depending on their technological...... distance from foreign firms. Domestic firms with smaller technological distance from their foreign counterparts tend to experience faster productivity growth, while firms with larger technological distance tend to lag further behind. We test this hypothesis using a unique firm-level data of Chinese...... manufacturing. Our empirical results confirm that foreign entry indeed generates strong heterogeneous growth patterns among domestic firms....

  10. Differential inhibitory action of apixaban on platelet and fibrin components of forming thrombi: Studies with circulating blood and in a platelet-based model of thrombin generation.

    Directory of Open Access Journals (Sweden)

    Lluis Pujadas-Mestres

    Full Text Available Mechanisms of action of direct oral anticoagulants (DOAC suggest a potential therapeutic use in the prevention of thrombotic complications in arterial territories. However, effects of DOACs on platelet activation and aggregation have not been explored in detail. We have investigated the effects of apixaban on platelet and fibrin components of thrombus formation under static and flow conditions.We assessed the effects of apixaban (10, 40 and 160 ng/mL on: 1 platelet deposition and fibrin formation onto a thrombogenic surface, with blood circulating at arterial shear-rates; 2 viscoelastic properties of forming clots, and 3 thrombin generation in a cell-model of coagulation primed by platelets.In studies with flowing blood, only the highest concentration of apixaban, equivalent to the therapeutic Cmax, was capable to significantly reduce thrombus formation, fibrin association and platelet-aggregate formation. Apixaban significantly prolonged thromboelastometry parameters, but did not affect clot firmness. Interestingly, results in a platelet-based model of thrombin generation under more static conditions, revealed a dose dependent persistent inhibitory action by apixaban, with concentrations 4 to 16 times below the therapeutic Cmax significantly prolonging kinetic parameters and reducing the total amount of thrombin generated.Our studies demonstrate the critical impact of rheological conditions on the antithrombotic effects of apixaban. Studies under flow conditions combined with modified thrombin generation assays could help discriminating concentrations of apixaban that prevent excessive platelet accumulation, from those that deeply impair fibrin formation and may unnecessarily compromise hemostasis.

  11. Knowledge management in the firm

    DEFF Research Database (Denmark)

    Rasmussen, Palle; Nielsen, Peter

    2011-01-01

    , transforming and utilizing various kinds of knowledge as a firm-specific asset is a very important element of firm competitiveness and innovative performance. In managing knowledge learning and innovation learning approaches are central. The paper identifies various approaches to learning and strategies...... of the importance of deliberately combining various approaches to innovation and learning in order to include a maximum of actors as sources in building knowledge assets and strategies. Research limitations/implications – Most of the empirical examples are from private sector enterprises, even though......Purpose – The purpose of this paper is to set focus on, and discuss the concept of knowledge, and show how the interrelations between knowledge and other concepts, such as learning, have become a decisive element in managing human resources and firm performance. Design...

  12. Audit firm rotation, audit firm tenure and earnings conservatism

    NARCIS (Netherlands)

    Kramer, S.T.; Georgakopoulos, G.; Sotiropoulos, I.; Vasileiou, K.Z.

    2011-01-01

    This study aims to contribute to the debate around the possibility of mandating audit firm rotation. Specifically, it examines conservatism as an attribute of earnings quality, which has not attracted particular attention in the auditor rotation research. Applying regression analyses on a sample,

  13. Firm Culture and Leadership as Firm Performance Predictors : a Resource-Based Perspective

    NARCIS (Netherlands)

    Wilderom, C.P.M.; van den Berg, P.

    2000-01-01

    In this study, we tested part of the resource-based view of the firm by examining two 'soft' resources, firm culture and top leadership, as predictors of 'hard' or bottom-line firm performance.Transformational top leadership was found to predict firm performance directly while the link between firm

  14. The Relationship between Offshoring Strategies and Firm Performance: Impact of innovation, absorptive capacity and firm size

    NARCIS (Netherlands)

    M.W. Roza-van Vuren (Marja)

    2011-01-01

    textabstractHow do offshoring strategies impact firm performance? And how are innovation, absorptive capacity and firm size influencing this relationship? This research investigates how firms of varying size, well-established firms and growing firms may profit from relocating business activities to

  15. A demographic approach to firm dynamics: formation of new firms and survival of old ones

    NARCIS (Netherlands)

    Nijkamp, P.; Geenhuizen, van M.

    1995-01-01

    This paper introduces a new approach to firm dynamics, named demography of firms. It is the study of demographic events in a population of firms. Thepaper argues that withina demographic approach, attention should be paid to a broad range of firm dynamics, including both new firm formation and

  16. How Firms Make Boundary Decisions

    DEFF Research Database (Denmark)

    Dobrajska, Magdalena; Billinger, Stephan; Becker, Markus

    2014-01-01

    , and (b) how the firm arrived at a particular transactional choice in each decision. We find that decision makers extensively adapt decision structures in order to effectively make governance mode choices. They adapt hierarchy span, i.e. the number of hierarchical levels involved, and expertise span, i...

  17. The firm-nature relationship

    DEFF Research Database (Denmark)

    Ulhøi, John Parm; Madsen, Henning

    2005-01-01

    Taking the stakeholder concept of the firm as a starting point, the paper presents data and analyses from a longitudinal study initiated in 1995 and repeated every four years. In discussing state-of-the-art insights and experiences, the paper identifies challenges which, if adequately addressed, ...

  18. Improving the firm's environmental conduct

    DEFF Research Database (Denmark)

    Knudsen, Thorbjørn; Koed Madsen, Tage

    2001-01-01

    lead to strategic advantage and, thus, economic gains at the firm level. In view of the great importance of this claim, the purpose of the present article was to apply resource-based insights in order to develop this reasoning further and provide an empirical test of three hypotheses related...

  19. Small firm transformation through IS

    NARCIS (Netherlands)

    Levy, Margi; Powell, Philip

    2008-01-01

    Globally, Small and Medium-sized Enterprises (SMEs) are encouraged, particularly by governments, to embrace c-business. Fully adopting e-business involves substantial change in firms, both internally and externally. However, there is little understanding of the mechanisms by which such business

  20. Why Do Distressed Firms Acquire?

    NARCIS (Netherlands)

    Q. Zhang (Quxian)

    2016-01-01

    textabstractAcquisitions made by distressed firms in recent years are economically important. This paper explores the rationale behind such acquisitions using a natural experiment. Exploiting a recent tax change which reduces debt restructuring costs for certain creditors and decreases bankruptcy

  1. Cloning and expression of clt genes encoding milk-clotting proteases from Myxococcus xanthus 422.

    Science.gov (United States)

    Poza, M; Prieto-Alcedo, M; Sieiro, C; Villa, T G

    2004-10-01

    The screening of a gene library of the milk-clotting strain Myxococcus xanthus 422 constructed in Escherichia coli allowed the description of eight positive clones containing 26 open reading frames. Only three of them (cltA, cltB, and cltC) encoded proteins that exhibited intracellular milk-clotting ability in E. coli, Saccharomyces cerevisiae, and Pichia pastoris expression systems.

  2. Drivers of Discretionary Firm Donations in Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo Bandeira-de-Mello

    2008-10-01

    Full Text Available Discretionary firm donation is usually related to the stakeholder theory and corporate social performance. Although theoretical explanations for this social behavior are pervasive in related literature, empirical modeling remains underdeveloped. We developed an explanatory structural model of discretionary firm donation using firm and industry level indicators. Unlike previous research, we estimated the explanatory power of the construct we called stakeholder orientation. Our tentative model was tested on a Brazilian sample of 101 publicly traded donor firms, using data on firm donations to social projects and to political candidates in electoral campaigns. The main results suggest that discretionary donation seems to be a strategy for managing conflicting claims in highly stakeholder oriented firms; the characteristics of the firm are more important than industry effects in explaining firm donations; and large firms, showing slack resources, and with a less concentrated ownership structure tend to engage in discretionary donation more intensively.

  3. Combination of recombinant factor VIIa and fibrinogen corrects clot formation in primary immune thrombocytopenia at very low platelet counts

    DEFF Research Database (Denmark)

    Larsen, Ole H; Stentoft, Jesper; Radia, Deepti

    2013-01-01

    Haemostatic treatment modalities alternative to platelet transfusion are desirable to control serious acute bleeds in primary immune thrombocytopenia (ITP). This study challenged the hypothesis that recombinant activated factor VII (rFVIIa) combined with fibrinogen concentrate may correct whole...... blood (WB) clot formation in ITP. Blood from ITP patients (n = 12) was drawn into tubes containing 3·2% citrate and corn trypsin inhibitor 18·3 μg/ml. WB [mean platelet count 22 × 10(9) /l (range 0-42)] was spiked in vitro with buffer, donor platelets (+40 × 10(9) /l), rFVIIa (1 or 4 μg/ml), fibrinogen...... low platelet counts. These data suggest that rFVIIa combined with fibrinogen corrects the coagulopathy of ITP even at very low platelet counts, and may represent an alternative to platelet transfusion....

  4. Job Creation by Firms in Denmark

    DEFF Research Database (Denmark)

    Ibsen, Rikke Falkner; Westergård-Nielsen, Niels

    time. A complication here is that firms switch ID over time because of change of ownership, mergers and divisions. Data must be corrected so that these administrative issues will not affect the survival of firms. The data are used in a way where we can cover firm birth and firm death, spin...... growth. For the U.S. it has been found that the growth in jobs comes from small businesses. A closer analysis though shows that the main factor here is the firm age. Thus, it is found that young firms net create the most jobs, but they are also responsible for the most job destructions....

  5. Entrepreneurship and the Economics of the Firm

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul

    The study of entrepreneurship and the study of economic organizing lack contact. In fact, the modern theory of the firm virtually ignores entrepreneurship, while the literature on entrepreneurship often sees little value in the economic theory of the firm. In contrast, we argue in this chapter...... that entrepreneurship theory and the theory of the firm can be usefully integrated, and that doing so would improve both bodies of theory. Adding the entrepreneur to the theory of the firm provides a dynamic view that the overly static analysis of firm organizing cannot support. Moreover, adding the firm to the study...... of the entrepreneur provides important clues to how we can understand entrepreneurship....

  6. Firm Based Trade Models and Turkish Economy

    Directory of Open Access Journals (Sweden)

    Nilüfer ARGIN

    2015-12-01

    Full Text Available Among all international trade models, only The Firm Based Trade Models explains firm’s action and behavior in the world trade. The Firm Based Trade Models focuses on the trade behavior of individual firms that actually make intra industry trade. Firm Based Trade Models can explain globalization process truly. These approaches include multinational cooperation, supply chain and outsourcing also. Our paper aims to explain and analyze Turkish export with Firm Based Trade Models’ context. We use UNCTAD data on exports by SITC Rev 3 categorization to explain total export and 255 products and calculate intensive-extensive margins of Turkish firms.

  7. The Identity of Ownership on Firm Internationalization

    DEFF Research Database (Denmark)

    Strandskov, Jesper; Madsen, Tage Koed; Pedersen, Bent

    2016-01-01

    The paper develops an integrative ownership-internationalization model that explores the influences of various owner types (i.e. investor-owned firms, family-owned firms, employee-owned firms, cooperative–owned firms, and state-owned firms) on firm internationalization. Based on a comparative...... analysis of the various owner types, we discuss how each owner group’s main objectives, risk behavior and provision of resources influence their internationalization strategies and decisions (i.e. scale, scope and speed decisions)....

  8. Technology Licensing and Firm Innovation

    DEFF Research Database (Denmark)

    Moreira, Solon

    that facilitate or constrain firms' ability to deal with licensed-in technologies have received little attention. This paper starts investigating in a longitudinal setting the effect of technology licensing on the number of patents produced by the licensee within the three years subsequent to the technology...... acquisition. The findings indicate that technology licensing is positively related to the number of inventions produced by the licensee in the years subsequent to the licensing deal. Subsequently, I investigate the moderating effect that organizational slack and myopia have on this main relationship....... The findings also suggest that high levels of Organizational Slack (available financial resources) strengthen the positive effect of licensing on innovation. However, higher levels of Organizational Myopia (the extent to which a firm draws on its own knowledge) can decrease the main effect of licensing....

  9. Technology Licensing and Firm Innovation

    DEFF Research Database (Denmark)

    Moreira, Solon

    acquisition. The findings indicate that technology licensing is positively related to the number of inventions produced by the licensee in the years subsequent to the licensing deal. Subsequently, I investigate the moderating effect that organizational slack and myopia have on this main relationship...... that facilitate or constrain firms' ability to deal with licensed-in technologies have received little attention. This paper starts investigating in a longitudinal setting the effect of technology licensing on the number of patents produced by the licensee within the three years subsequent to the technology....... The findings also suggest that high levels of Organizational Slack (available financial resources) strengthen the positive effect of licensing on innovation. However, higher levels of Organizational Myopia (the extent to which a firm draws on its own knowledge) can decrease the main effect of licensing....

  10. Firm Exit, Technological Progress and Trade

    DEFF Research Database (Denmark)

    Schröder, Philipp; Sørensen, Allan

    The dynamics of export market exit and firm closure have found limited attention in the new heterogeneous-firms trade literature. In fact, several of the predictions on firm survival and exit stemming from this new class of models are at odds with the stylized facts. Empirically, higher...... productivity firms survive longer, most firm closures are young firms, higher productivity exporters are more likely to continue to export compared to less productive exporters and market exits as well as firm closures are typically preceded by periods of contracting market shares. The present paper shows...... that the simple inclusion of exogenous economy wide technological progress into the standard Melitz (2003) model generates a tractable dynamic framework that generates endogenous exit decisions of firms in line with the stylized facts. Furthermore, we derive the effects of faster technological progress and trade...

  11. How do Economic Crises Impact Firm Boundaries?

    DEFF Research Database (Denmark)

    Foss, Kirsten

    2010-01-01

    How economic crises impact the boundaries of firms has been offered virtually no attention in the literature on the theory of the firm. I review the best-known theories of the firm and identify the variables that matter for the explanation of firm boundaries. I then examine how an economic crisis...... may impact these variables and change efficient firm boundaries. The various theories of the firm have difficulties explaining how firms efficiently adapt their boundaries to such prominent characteristics of economic crisis as declining demand and increased costs of external finance. However, all...... these theories stress uncertainty as an antecedent of firm organization, and as uncertainty is also an important characteristic of an economic crisis I examine how uncertainty is allowed to play out in the various theories in order to identify what predictions we can derive from the theory regarding changes...

  12. Multiple Blockholder Structures and Family Firm Performance

    DEFF Research Database (Denmark)

    Fattoum-Guedri, Asma; Guedri, Zied; Delmar, Frédéric

    2018-01-01

    This study examines how multiple blockholder structures affect family firm performance. Building on arguments from both principal–principal agency and familiness perspectives, we suggest that asymmetrical distribution of voting power among family and nonfamily blockholders hurts firm performance....

  13. Heterogeneity in Firm Performance During Economic Crisis

    Directory of Open Access Journals (Sweden)

    Sergio Bruni

    2014-06-01

    Full Text Available What happens to firms during periods of deep economic crisis? Did different types of firms perform differently under the economic crisis? With the aid of a rich database and focusing on the literature regarding the growth of firms, this paper investigates the relative profitability performance of Italian firms during the current economic crisis, exploring those factors, which help certain firms to do relatively better even in the slowdown period. Some preliminary results show that the Italian firms that are relatively young in age, with relatively better current liquidity and more focused on domestic market have performed better than other firms. Furthermore, firms operating in high-tech and in highly concentrated sectors have enjoyed a better performance in this period.

  14. Entrepreneurship and the Economics of the Firm

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul

    The study of entrepreneurship and the study of economic organizing lack contact. In fact, the modern theory of the firm virtually ignores entrepreneurship, while the literature on entrepreneurship often sees little value in the economic theory of the firm. In contrast, we argue in this chapter th...... of the entrepreneur provides important clues to how we can understand entrepreneurship.......The study of entrepreneurship and the study of economic organizing lack contact. In fact, the modern theory of the firm virtually ignores entrepreneurship, while the literature on entrepreneurship often sees little value in the economic theory of the firm. In contrast, we argue in this chapter...... that entrepreneurship theory and the theory of the firm can be usefully integrated, and that doing so would improve both bodies of theory. Adding the entrepreneur to the theory of the firm provides a dynamic view that the overly static analysis of firm organizing cannot support. Moreover, adding the firm to the study...

  15. Unions, training and firm performance

    OpenAIRE

    Addison, John T.; Belfield, Clive R.

    2007-01-01

    The present paper uses a combination of workplace and linked employee-workplace data from the 1998 Workplace Employee Relations Survey and the 2004 Workplace Employment Relations Survey to examine the impact of unions on training incidence, training intensity/coverage, and training duration. It also examines the impact of unions and training on earnings and a measure of establishment labour productivity. In addition, the implications of training for the firm's bottom line are evaluated. Union...

  16. Firm Decisions: Determinants of Investments

    OpenAIRE

    Ionescu Alexandra

    2011-01-01

    The investment decision is part of a companies’ investment strategy. Defined as a logical set of technical and economic information, the investment strategy determines the main objectives of the firm regarding its investments, based on studies, analysis and simulations. It also establishes the actions to be undertaken in order to achieve the objectives, methods of achieving them, sources of funding and resource allocation methods. Still, all these are influenced by several factors. The invest...

  17. Cost Stickiness in Brazilian Firms

    OpenAIRE

    Otavio Ribeiro De Medeiros; Patricia de Souza Costa

    2004-01-01

    Conventional cost accounting assumes that the relation between cost and volume is symmetric for volume increases and decreases. We test an alternative model where costs increase more when activity rises than they decrease when activity falls by an equivalent amount. We find, for a sample of Brazilian firms that selling, general, and administrative costs increase 0.59% per 1% increase in sales but decrease only 0.32% per 1% decrease in sales. We test several hypotheses about the properties of ...

  18. 10 CFR 603.1230 - Commercial firm.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Commercial firm. 603.1230 Section 603.1230 Energy... Used in this Part § 603.1230 Commercial firm. A for-profit firm or segment of a for-profit firm (e.g., a division or other business unit) that does a substantial portion of its business in the commercial...

  19. Architectural firms: workforce, business strategy and performance

    OpenAIRE

    Oluwatayo, Adedapo Adewunmi; Amole, Dolapo

    2011-01-01

    The intent of this research was to investigate the relationship between the workforce, business strategy and performance of architectural firms. Data was collected from 92 firms randomly selected from the cities where architectural firms were most concentrated in Nigeria using questionnaires. Hierarchical regression analysis was carried out to investigate the direct and indirect impacts of the workforce of architectural firms on their performance. The findings confirm the significant positive...

  20. The 'Shadow of Succession' in Family Firms

    OpenAIRE

    Diwisch, Sandra Denise; Voithofer, Peter; Weiss, Christoph

    2005-01-01

    The paper analyses the relationship between succession and firm performance. Using a unique panel data set on a sample of roughly 4,000 Austrian family firms we examine empirically the impact of past succession as well as future succession plans on employment growth and investment behaviour. Analysing succession plans, we do not find a 'shadow of succession' effect. No significant difference in employment growth and investment behaviour is found between firms that plan to transfer the firm in...

  1. Human Capital and Wages in Exporting Firms

    DEFF Research Database (Denmark)

    Munch, Jakob Roland; Skaksen, Jan Rose

    2006-01-01

    This paper studies the link between a firms education level, export performance and wages of its workers. We argue that firms may escape intence competition in international markets by using high skilled workers to differentiate their products. This story is consistent with our empirical results....... an export wage premium, but it accrues to workers in firms with high skill intensities.Keywords: Exports, Wages, Human Capital, Rent Sharing, Matched Worker-Firm DataJEL Classification: J30, F10, I20...

  2. International Taxation and Multinational Firm Location Decisions

    OpenAIRE

    Salvador Barrios; Harry Huizinga; Luc Laeven; Gaëtan Nicodème

    2008-01-01

    Using a large international firm-level data set, we estimate separate effects of host and parent country taxation on the location decisions of multinational firms. Both types of taxation are estimated to have a negative impact on the location of new foreign subsidiaries. In fact, the impact of parent country taxation is estimated to be relatively large, possibly reflecting its international discriminatory nature. For the cross-section of multinational firms, we find that parent firms tend to ...

  3. Firm Heterogeneity, Credit Constraints, and Endogenous Growth

    OpenAIRE

    Torben Klarl; Alfred Maussner

    2010-01-01

    This paper is concerned with the role of firm heterogeneity under credit constraints for economic growth. We focus on firm size, innovativeness and credit constraints in a semi-endogenous growth model reflecting recent empirical findings on firm heterogeneity. It allows for an explicit solution for transitional growth and balanced growth path productivity as well as the growth maximizing firm heterogeneity. This enables us to draw inference about the impact of key policy parameters of the mod...

  4. Does Labour Diversity affect Firm Productivity?

    DEFF Research Database (Denmark)

    Parrotta, Pierpaolo; Pozzoli, Dario; Pytlikova, Mariola

    Using a matched employer-employee dataset, we analyze how workforce diversity in cultural background, education and demographic characteristics affects productivity of firms in Denmark. Implementing a structural estimation of the firms' production function (Ackerberg et al., 2006) we find...... that labor diversity in education significantly enhances a firm's value added. Conversely, diversity in ethnicity and demographics induces negative effects on firm productivity. Hence, the negative effects, coming from communication and integration costs connected to a more culturally and demographically...

  5. Fibrinolytic action on fresh human clots of whole body extracts and two semipurified fractions from Lonomia achelous caterpillar

    Directory of Open Access Journals (Sweden)

    E. Coll-Sangrona

    1998-06-01

    Full Text Available The severe bleeding diathesis produced by intoxication with the venom of Lonomia achelous caterpillars is characterized by prolonged bleeding from superficial skin wounds as well as massive hemorrhage into body cavities. The aim of the present study was to evaluate the effect of the crude venom and its fibrinolytic fractions on in vitro lysis of whole blood clots. Venom fractions with fibrinolytic activity were obtained by gel filtration chromatography on Sephadex G75 using imidazole buffer, pH 7.4, at a flow rate of 24 ml/h. Four peaks with fibrinolytic activity were obtained by this method. The highest activity was found in the first two peaks (both peaks were used for the experiments. The results show that the caterpillar venom degraded the preformed clots at a slower rate than plasmin. In addition, plasma protease inhibitors of the fibrinolytic system (a2-antiplasmin, a2-macroglobulin, PAI, etc. only weakly inhibited the lytic effect of the caterpillar venom. These characteristics, as well as the pattern of fibrinogen degradation products, the delay period on fibrin plate lysis and amidolytic activity on chromogenic substrate, reported previously, indicate that the caterpillar enzymes are different from plasmin and trypsin.

  6. 78 FR 70987 - Proxy Advisory Firm Roundtable

    Science.gov (United States)

    2013-11-27

    ... COMMISSION Proxy Advisory Firm Roundtable AGENCY: Securities and Exchange Commission. ACTION: Notice of... roundtable about proxy advisory firms. The panel will be asked to discuss topics including the current state of proxy advisory firm use by investment advisers and institutional investors and potential changes...

  7. Reputational penalties to firms in antitrust investigations

    NARCIS (Netherlands)

    Broek, van den S.; Kemp, R.G.M.; Verschoor, W.F.C.; Vries, de A.

    2012-01-01

    We estimate the impact of legal penalties imposed on Dutch listed firms targeted by competition authorities from 1998 to 2008 on a firm's stock market value. On average, firms lose 2.3 percent of their market values when an antitrust investigation is uncovered. This corresponds to a total value loss

  8. FOOD ENTREPRENEUR SUSTAINABLE ORIENTATION AND FIRM PRACTICES

    OpenAIRE

    Mark A. Gagnon; Pamela A. Heinrichs

    2016-01-01

    This exploratory research examines the relationship between food entrepreneur sustainable orientation, mindset and firm sustainable practices in a mixed methods format. In particular we seek to address if entrepreneur behavior and firm practices are congruent with founding entrepreneur espoused support of sustainability. Our survey findings with thirty specialty food entrepreneurs suggest tenuous empirical support for the relationship of entrepreneur sustainable orientation, mindset and firm ...

  9. The Dividend Policy of German Firms

    NARCIS (Netherlands)

    Andres, C.; Betzer, A.; Goergen, M.; Renneboog, L.D.R.

    2008-01-01

    Abstract: German firms pay out a lower proportion of their cash flows, but a higher proportion of their published profits than UK and US firms. We estimate partial adjustment models and report two major findings. First, German firms base their dividend decisions on cash flows rather than published

  10. The Dividend Policy of German Firms

    NARCIS (Netherlands)

    Andres, C.; Betzer, A.; Goergen, M.; Renneboog, L.D.R.

    2008-01-01

    German firms pay out a lower proportion of their cash flows, but a higher proportion of their published profits than UK and US firms. We estimate partial adjustment models and report two major findings. First, German firms base their dividend decisions on cash flows rather than published earnings as

  11. Finding the "Right Staff" in Small Firms

    Science.gov (United States)

    Barrett, Rowena; Neeson, Robyn; Billington, Leo

    2007-01-01

    Purpose: The purpose of this paper is to explore what owners of small firms are looking for from new employees. The aim is to pursue this in light of the debate around formality and informality of small firm HRM, exploring the extent to which the small firms studied had formalized HRM practices. Design/methodology/approach: The data reported here…

  12. Related party transactions and firms financial performance ...

    African Journals Online (AJOL)

    The study investigated related party transactions and firm's financial performance using Secondary data obtained from Nigeria stock Exchange. We tried to determine whether RPT is used by firms to manipulate and bloat Return on Asset, Return on Equity and Earnings per share of manufacturing firms. RPT was subjected ...

  13. Endogenous Markups, Firm Productivity and International Trade:

    DEFF Research Database (Denmark)

    Bellone, Flora; Musso, Patrick; Nesta, Lionel

    In this paper, we test key micro-level theoretical predictions ofMelitz and Ottaviano (MO) (2008), a model of international trade with heterogenous firms and endogenous mark-ups. At the firm-level, the MO model predicts that: 1) firm markups are negatively related to domestic market size; 2...

  14. Firm-Level Corruption in Vietnam

    DEFF Research Database (Denmark)

    Rand, John; Tarp, Finn

    This paper uses a unique panel dataset on firm-level corruption. It contains quantitative information on bribe payments by a sample of formal and informal Vietnamese firms. We show that bribe incidence is highly associated with firm-level differences in (i) visibility, (ii) sunk costs, (iii...

  15. New Firm Growth: Exploring Processes and Paths

    NARCIS (Netherlands)

    E. Garnsey; F.C. Stam (Erik); P. Heffernan; O. Hugo

    2003-01-01

    textabstractThis paper provides a new methodology for the diachronic study of new firm growth, theoretically grounded in the work of Penrose (1995). We show that a model of firm growth as an unfolding process makes possible draw simple, measurable inferences from firm level to aggregate evidence on

  16. Uncertainty and growth of the firm

    NARCIS (Netherlands)

    Lensink, Robert; Steen, Paul van der; Sterken, Elmer

    2000-01-01

    Using data from a survey of 1097 Dutch firms we investigate the relation between growth of the firm and uncertainty. We focus on the impact of uncertainty on various types of investment, employment demand, and expected maturity of the firm. The special feature of the survey is that it includes data

  17. The Impact of Firm-Provided Training on Production: Testing for Firm-Size Effects

    NARCIS (Netherlands)

    J.M.P. de Kok (Jan)

    2000-01-01

    textabstractThe returns to firm-provided training depend on many different factors. Firm size is an important indicator of various of these factors, but recent research tends to neglect it. In this study the returns to firm-provided training are estimated, taking account of three possible firm-size

  18. Effect of Lipid Surface Composition on the Formation and Structure of Fibrin Clots.

    Science.gov (United States)

    Bakirova, D R; Faizullin, D A; Valiullina, Yu A; Salnikov, V V; Zuev, Yu F

    2017-10-01

    We studied the influence of lipid surface composition on the kinetics of fibrin clot formation and its structure. It was shown that lipid surface affects all phases of fibrin polymerization and chances clot morphology. The magnitude and character of the effect depend on the charge and phase state of lipids that determine the interaction of fibrinogen with the lipid surface and its conformational changes, which modulated the process of fibrinogen conversion into fibrin and, as a result, the formation and morphology of the fibrin clot.

  19. [Guidelines for certification of Activated clotting time (ACT) according to the EN ISO 22870 standards].

    Science.gov (United States)

    Lasne, Dominique; Bauters, Anne; Le Querrec, Agnès; Bourdin, Carole; Voisin, Sophie

    2015-01-01

    Point of care testing (POCT) must comply with regulatory requirements according to standard EN ISO 22870, which identify biologists as responsible for POCT. Activated clotting time (ACT) is mandatory to monitor on whole blood, anticoagulation achieved by unfractionated heparin during cardiopulmonary bypass (CPB) or cardiac catheterization. This test has no equivalent in the laboratory. With the aim to help the multidisciplinary groups for POCT supervision when they have to analyse the wish of medical departments to use ACT and to help the biologists to be in accordance with the standard, we present the guidelines of the GEHT (Groupe d'étude d'hémostase et thrombose) subcommittee "CEC et Biologie délocalisée" for the certification of ACT. These guidelines are based on the SFBC guidelines for the certification of POCT and on the analysis of the literature to ascertain the justification of clinical need and assess the analytical performance of main analyzers used in France, as well as on a survey conducted with French and Belgian biologists.

  20. Essays on Firm Behavior in Developing Economies

    Science.gov (United States)

    Abeberese, Ama Baafra

    The performance of firms is central to growth in developing economies. A burgeoning literature within development economics seeks to understand the behavior of firms in developing countries and the constraints to their performance. This dissertation explores two types of constraints---infrastructure-related constraints and trade-related constraints---faced by manufacturing firms in developing countries. Despite the widely acknowledged importance of infrastructure for economic growth, there has been relatively little research on how infrastructure affects the decisions of firms. Electricity, in particular, is commonly cited by firms in developing countries as a major obstacle to their performance. In the first two chapters, I analyze the responses of firms to two types of electricity constraints, namely electricity prices and electricity shortages. Chapter 1 provides evidence on how electricity prices affect a firm's industry choice and productivity growth using data on Indian manufacturing firms. I construct an instrument for electricity price as the interaction between the price of coal paid by power utilities, which is arguably exogenous to firm characteristics, and the initial share of thermal generation in a state's total electricity generation capacity. I find that, in response to an exogenous increase in electricity price, firms reduce their electricity consumption and switch to industries with less electricity-intensive production processes. I also find that firm output, machine intensity and labor productivity decline with an increase in electricity price. In addition to these level effects, I show that firm output and productivity growth rates are negatively affected by high electricity prices. These results suggest that electricity constraints faced by firms may limit a country's growth by leading firms to operate in industries with fewer productivity-enhancing opportunities. Chapter 2 examines the impact of electricity shortages on firm investment. I

  1. Corporate governance, analyst following and firm value

    OpenAIRE

    Mouselli, Sulaiman; Hussainey, Khaled

    2014-01-01

    Purpose – The purpose of this paper is to examine the impact of a firm’s corporate governance (CG) mechanisms on the number of financial analysts following UK firms. The potential effect of the number of analysts following firms in the UK on the association betweenCGmechanisms and firm value was also examined. Design/methodology/approach – Multiple regression models were used to examine the association between CG, analyst coverage and firm value for a large sample of UK firms listed in London...

  2. Performance of Patenting Firms in Danish Manufacturing

    DEFF Research Database (Denmark)

    Madsen, Erik Strøjer; Smith, Valdemar; Nielsen, Anders Østergaard

    2000-01-01

    Most countries focus on industries with high technology and the governments grant subsidies to innovating firms. However, there has been remarkable few studies of the performance of innovative firms or industries. This study examines the performance of patent active firms compared to the non......-patenting firms within the manufacturing sector in Denmark. Performance is measured both by growth in employment as well as in the return on equity and profit share in turnover. The results suggest that differences in performance of patenting and non-patenting firms are very small, which questions the political...

  3. Political uncertainty and firm risk in China

    Directory of Open Access Journals (Sweden)

    Danglun Luo

    2017-12-01

    Full Text Available The political uncertainty surrounded by the turnover of government officials has a major impact on local economies and local firms. This paper investigates the relationship between the turnover of prefecture-city officials and the inherent risk faced by local firms in China. Using data from 1999 to 2012, we find that prefecture-city official turnovers significantly increased firm risk. Our results show that the political risk was mitigated when new prefecture-city officials were well connected with their provincial leaders. In addition, the impact of political uncertainty was more pronounced for regulated firms and firms residing in provinces with low market openness.

  4. Toward an Integrative Theory of the Firm

    DEFF Research Database (Denmark)

    Li, Xin

    understand the nature and behaviors of the firm, we need a comprehensive yet integrative theory. Toward this end, this paper proposes a relationship-based theory of the firm (R’BT) which claims that it is the relationships between the entrepreneur and other individuals or firms that determine the existence......This paper argues that the existing four major theories of the firm, i.e., the transaction cost theory, resource-based view, the entrepreneurial theory, and the stakeholder theory, are all insightful yet partial because each of them has a particular focus on the phenomenon of the firm. To better...

  5. Do Treasure Islands Create Firm Value?

    DEFF Research Database (Denmark)

    Lai, Tat-kei; Ng, Travis

    They do! Otherwise, their use would not have been so prevalent among firms. How much firm value they create, however, is still an open question. Exploiting a political event in the U.K. that suddenly raised the cost of using tax havens, we find that there was a 0.87% reduction in cumulative...... abnormal return (CAR) among the sampled firms, corresponding to about £532 million in market capitalization. The firms of stronger corporate governance registered a stronger reduction in CAR. A simple linear extrapolation suggests that the firm value contributed by tax havens can be as much as £31 billion....

  6. The theory of the firm. Vol. 1

    DEFF Research Database (Denmark)

    their internal organization. This collection documents the rise of the modern theory of the firm during the last two to three decades. It reprints classic writings from a diversity of perspectives, including not only contractual theories of the firm, but also knowledge-based theories and theories of the firm...... as an information processor. In addition, the collection features perspectives from business strategy and business history as well as methodological and doctrinal historical perspectives. Including over 60 classic papers, these volumes collect together contributions on the theory of the firm, beginning with Ronald......Firms have for a long time been part of the explanatory set-up of economics. However, it is only recently that economists have felt the need for an economic theory addressing: why firms are different; why firms exist; what determines their boundaries relative to "the market"; and what determines...

  7. The theory of the firm. Vol. 2

    DEFF Research Database (Denmark)

    Firms have for a long time been part of the explanatory set-up of economics. However, it is only recently that economists have felt the need for an economic theory addressing: why firms are different; why firms exist; what determines their boundaries relative to "the market"; and what determines...... their internal organization. This collection documents the rise of the modern theory of the firm during the last two to three decades. It reprints classic writings from a diversity of perspectives, including not only contractual theories of the firm, but also knowledge-based theories and theories of the firm...... as an information processor. In addition, the collection features perspectives from business strategy and business history as well as methodological and doctrinal historical perspectives. Including over 60 classic papers, these volumes collect together contributions on the theory of the firm, beginning with Ronald...

  8. The theory of the firm. Vol. 1

    DEFF Research Database (Denmark)

    Firms have for a long time been part of the explanatory set-up of economics. However, it is only recently that economists have felt the need for an economic theory addressing: why firms are different; why firms exist; what determines their boundaries relative to "the market"; and what determines...... their internal organization. This collection documents the rise of the modern theory of the firm during the last two to three decades. It reprints classic writings from a diversity of perspectives, including not only contractual theories of the firm, but also knowledge-based theories and theories of the firm...... as an information processor. In addition, the collection features perspectives from business strategy and business history as well as methodological and doctrinal historical perspectives. Including over 60 classic papers, these volumes collect together contributions on the theory of the firm, beginning with Ronald...

  9. The theory of the firm. Vol. 4

    DEFF Research Database (Denmark)

    Firms have for a long time been part of the explanatory set-up of economics. However, it is only recently that economists have felt the need for an economic theory addressing: why firms are different; why firms exist; what determines their boundaries relative to "the market"; and what determines...... their internal organization. This collection documents the rise of the modern theory of the firm during the last two to three decades. It reprints classic writings from a diversity of perspectives, including not only contractual theories of the firm, but also knowledge-based theories and theories of the firm...... as an information processor. In addition, the collection features perspectives from business strategy and business history as well as methodological and doctrinal historical perspectives. Including over 60 classic papers, these volumes collect together contributions on the theory of the firm, beginning with Ronald...

  10. The theory of the firm. Vol. 3

    DEFF Research Database (Denmark)

    Firms have for a long time been part of the explanatory set-up of economics. However, it is only recently that economists have felt the need for an economic theory addressing: why firms are different; why firms exist; what determines their boundaries relative to "the market"; and what determines...... their internal organization. This collection documents the rise of the modern theory of the firm during the last two to three decades. It reprints classic writings from a diversity of perspectives, including not only contractual theories of the firm, but also knowledge-based theories and theories of the firm...... as an information processor. In addition, the collection features perspectives from business strategy and business history as well as methodological and doctrinal historical perspectives. Including over 60 classic papers, these volumes collect together contributions on the theory of the firm, beginning with Ronald...

  11. Division of Labor, Transaction Cost, Emergence of the Firm and Firm Size

    OpenAIRE

    Pak-Wai Liu; Xiaokai Yang

    1999-01-01

    In this paper a general equilibrium model is constructed to explain the emergence of firms and change in firm size by the tradeoff between economies of specialization and transaction cost. We show that firms emerge from the development of division of labor if the transaction efficiency for labor is smaller than that for intermediate goods. Given the emergence of firms, change in the average size of firms (average employment) will depend on the change in transaction efficiency for intermediate...

  12. Determinants of CEO Turnover in Publicand Private Firms in Denmark - CEO and Firm Characteristics

    DEFF Research Database (Denmark)

    Sponholtz, Carina

    turnover. Finally, the inverse relationshipbetween firm performance and CEO turnover only exists in LLL firms(larger limited liability firms, both publicly and privately held), whereagency costs are assumed and found to be highest.In this study we are the first to draw on longitudinal matched employer...... only exists in LLL firms(larger limited liability firms, both publicly and privately held), whereagency costs are assumed and found to be highest....

  13. Firm Heterogeneity and the Choice of Internationalization Modes: Statistical Evidence from Japanese Firm-level Data

    OpenAIRE

    WAKASUGI Ryuhei; TANAKA Ayumu

    2009-01-01

    This paper examines how productivity heterogeneity affects the sorting of export and foreign direct investment (FDI) of Japanese firms in North America and Europe. The statistical analysis based on the firm-level data of 12,000 Japanese firms presents new and interesting results: the ranking of productivity corresponds to the mode of internationalization from export to FDI; the productivity of Japanese firms with exports to North America is similar to the productivity of firms with exports to...

  14. Firm Innovation and the Ratchet Effect Among Consumer Packaged Goods Firms

    OpenAIRE

    Christine Moorman; Simone Wies; Natalie Mizik; Fredrika J. Spencer

    2012-01-01

    We consider how public firms influence their stock market valuations by timing the introduction of innovative new products. Our focus is on innovation ratchet strategy --firms timing the introduction of innovations in order to demonstrate an improvement in the number of introductions over time. We document that public firms use an innovation ratchet strategy more often than do private firms and that the stock market rewards public firms for doing so. These rewards from the stock market, howev...

  15. Development and comparison of a minimally-invasive model of autologous clot pulmonary embolism in Sprague-Dawley and Copenhagen rats

    Directory of Open Access Journals (Sweden)

    Sanapareddy Nina

    2010-02-01

    Full Text Available Abstract Background Experimental models of pulmonary embolism (PE that produce pulmonary hypertension (PH employ many different methods of inducing acute pulmonary occlusion. Many of these models induce PE with intravenous injection of exogenous impervious objects that may not completely reproduce the physiological properties of autologous thromboembolism. Current literature lacks a simple, well-described rat model of autlogous PE. Objective: Test if moderate-severity autologous PE in Sprague-Dawley (SD and Copenhagen (Cop rats can produce persistent PH. Methods blood was withdrawn from the jugular vein, treated with thrombin-Ca++ and re-injected following pretreatment with tranexamic acid. Hemodynamic values, clot weights and biochemical measurements were performed at 1 and 5 days. Results Infusion of clot significantly increased the right ventricular peak systolic pressure to 45-55 mm Hg, followed by normalization within 24 hours in SD rats, and within 5 days in COP rats. Clot lysis was 95% (24 hours and 97% (5 days in SD rats and was significantly lower in COP rats (70%, 24 hours; 87% 5 days. Plasma D-dimer was elevated in surgical sham animals and was further increased 8 hours after pulmonary embolism. Neither strain showed a significant increase in bronchoalveolar chemotactic activity, myeloperoxidase activity, leukocyte infiltration, or chemokine accumulation, indicating that there was no significant pulmonary inflammation. Conclusions Both SD and COP rats exhibited near complete fibrinolysis of autologous clot PE within 5 days. Neither strain developed persistent PH. Experimental models of PE designed to induce sustained PH and a robust inflammatory response appear to require significant, persistent pulmonary vascular occlusion.

  16. Freeze-dried plasma enhances clot formation and inhibits fibrinolysis in the presence of tissue plasminogen activator similar to pooled liquid plasma.

    Science.gov (United States)

    Huebner, Benjamin R; Moore, Ernest E; Moore, Hunter B; Sauaia, Angela; Stettler, Gregory; Dzieciatkowska, Monika; Hansen, Kirk; Banerjee, Anirban; Silliman, Christopher C

    2017-08-01

    Systemic hyperfibrinolysis is an integral part of trauma-induced coagulopathy associated with uncontrolled bleeding. Recent data suggest that plasma-first resuscitation attenuates hyperfibrinolysis; however, the availability, transport, storage, and administration of plasma in austere environments remain challenging and have limited its use. Freeze-dried plasma (FDP) is a potential alternative due to ease of storage, longer shelf life, and efficient reconstitution. FDP potentially enhances clot formation and resists breakdown better than normal saline (NS) and albumin and similar to liquid plasma. Healthy volunteers underwent citrated blood draw followed by 50% dilution with NS, albumin, pooled plasma (PP), or pooled freeze-dried plasma (pFDP). Citrated native and tissue plasminogen activator (t-PA)-challenge (75 ng/mL) thrombelastography were done. Proteins in PP, pFDP, and albumin were analyzed by mass spectroscopy. pFDP and PP had superior clot-formation rates (angle) and clot strength (maximum amplitude) compared with NS and albumin in t-PA-challenge thrombelastographies (angle: pFDP, 67.9 degrees; PP, 67.8 degrees; NS, 40.6 degrees; albumin, 35.8 degrees; maximum amplitude: pFDP, 62.4 mm; PP, 63.5 mm; NS, 44.8 mm; albumin, 41.1 mm). NS and albumin dilution increased susceptibility to t-PA-induced hyperfibrinolysis compared with pFDP and PP (NS, 62.4%; albumin, 62.6%; PP, 8.5%; pFDP, 6.7%). pFDP was similar to PP in the attenuation of t-PA-induced fibrinolysis. Most proteins (97%) were conserved during the freeze-dry process, with higher levels in 12% of pFDP proteins compared with PP. pFDP enhances clot formation and attenuates hyperfibrinolysis better than NS and albumin and is a potential alternative to plasma resuscitation in the treatment of hemorrhagic shock. © 2017 AABB.

  17. Time-dependent low-field MRI characteristics of canine blood: an in vitro study.

    Science.gov (United States)

    Jeong, Jimo; Park, Sangjun; Jeong, Eunseok; Kim, Namsoo; Kim, Minsu; Jung, Yechan; Cho, Youngkwon; Lee, Kichang

    2016-03-01

    This study was conducted to assess time-sensitive magnetic resonance (MR) changes in canine blood using low-field MR. Arterial and venous blood samples were collected from eight healthy beagle dogs. Samples were placed in 5-mL tubes and imaged within 3 hours of collection at 1 day intervals from day 1 to day 30. The following sequences were used: T1-weighted (T1W), T2-weighted (T2W), fluid-attenuated inversion recovery (FLAIR), short tau inversion recovery (STIR), and T2-star gradient-echo (T2(*)-GRE). Visual comparison of the images revealed that four relatively homogenous blood clots and twelve heterogeneous blood clots developed. The margination of the clot and plasma changed significantly on day 2 and day 13. On day 2, heterogeneous blood clots were differentiated into 2 to 3 signal layers in the T2W, T1W, and especially the STIR images. Hypointense signal layers were also detected in the blood clots in STIR images, which have T2 hypo, FLAIR hypo, and T1 hyper intense signals. In all images, these signal layers remained relatively unchanged until day 13. Overall, the results suggest that hematomas are complex on low-field MRI. Accordingly, it may not be feasible to accurately characterize hemorrhages and predict clot age based on low-field MRI.

  18. Dynamics of motion of a clot through an arterial bifurcation: a finite element analysis

    Energy Technology Data Exchange (ETDEWEB)

    Abolfazli, Ehsan; Fatouraee, Nasser [Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Vahidi, Bahman, E-mail: e.abolfazli@aut.ac.ir, E-mail: nasser@aut.ac.ir, E-mail: bahman_vahidi@ut.ac.ir [Department of Life Science Engineering, Faculty of New Sciences and Technologies, University of Tehran (Iran, Islamic Republic of)

    2014-10-01

    Although arterial embolism is important as a major cause of brain infarction, little information is available about the hemodynamic factors which govern the path emboli tend to follow. A method which predicts the trajectory of emboli in carotid arteries would be of a great value in understanding ischemic attack mechanisms and eventually devising hemodynamically optimal techniques for prevention of strokes. In this paper, computational models are presented to investigate the motion of a blood clot in a human carotid artery bifurcation. The governing equations for blood flow are the Navier–Stokes formulations. To achieve large structural movements, the arbitrary Lagrangian–Eulerian formulation (ALE) with an adaptive mesh method was employed for the fluid domain. The problem was solved by simultaneous solution of the fluid and the structure equations. In this paper, the phenomenon was simulated under laminar and Newtonian flow conditions. The measured stress–strain curve obtained from ultrasound elasticity imaging of the thrombus was set to a Sussman–Bathe material model representing embolus material properties. Shear stress magnitudes in the inner wall of the internal carotid artery (ICA) were measured. High magnitudes of wall shear stress (WSS) occurred in the areas in which the embolus and arterial are in contact with each other. Stress distribution in the embolus was also calculated and areas prone to rapture were identified. Effects of embolus size and embolus density on its motion velocity were investigated and it was observed that an increase in either embolus size or density led to a reduction in movement velocity of the embolus. Embolus trajectory and shear stress from a simulation of embolus movement in a three-dimensional model with patient-specific carotid artery bifurcation geometry are also presented.

  19. The Phosphatase Inhibitor Calyculin-A Impairs Clot Retraction, Platelet Activation, and Thrombin Generation

    Directory of Open Access Journals (Sweden)

    Renáta Hudák

    2017-01-01

    Full Text Available The aim of this study was to investigate the effect of the serine/threonine protein phosphatase inhibitor, calyculin-A (CLA, on clot formation and on the procoagulant activity of human platelets. Platelet-rich plasma (PRP samples were preincubated with buffer or CLA and subsequently platelets were activated by the protease-activated receptor 1 (PAR-1 activator, thrombin receptor activating peptide (TRAP. Clot retraction was detected by observing clot morphology up to 1 hour, phosphatidylserine- (PS- expression was studied by flow cytometry, and thrombin generation was measured by a fluorimetric assay. For the intracellular Ca2+ assay, platelets were loaded with calcium-indicator dyes and the measurements were carried out using a ratiometric method with real-time confocal microscopy. CLA preincubation inhibited clot retraction, PS-expression, and thrombin formation. TRAP activation elicited Ca2+ response and PS-expression in a subset of platelets. The activated PRP displayed significantly faster and enhanced thrombin generation compared to nonactivated samples. CLA pretreatment abrogated PS-exposure and clot retraction also in TRAP-activated samples. As a consequence of the inhibitory effect on calcium elevation and PS-expression, CLA significantly downregulated thrombin generation in PRP. Our results show that CLA pretreatment may be a useful tool to investigate platelet activation mechanisms that contribute to clot formation and thrombin generation.

  20. Plasma fibrin clot properties in postmenopausal women: effects of hormone therapy.

    Science.gov (United States)

    Piróg, Magdalena M; Milewicz, Tomasz; Jach, Robert; Undas, Anetta

    2016-05-01

    Postmenopausal women are at risk of thromboembolic events. It is unclear whether menopause alters fibrin clot properties. The aim of our study was to assess the effects of menopause and hormone therapy on clot characteristics. Ex vivo plasma clot permeability, turbidity, and susceptibility to lysis were determined in 70 premenopausal and 70 postmenopausal women (a case-control study). From the postmenopausal group, 30 women were randomly assigned (1:1) to a 24-week oral or transdermal treatment with 17β-estradiol, combined with norethisterone acetate (2 mg + 1 mg/d or 0.05 mg + 5 mg/d, respectively). Compared with premenopausal women (aged 29.2 ± 2.60 y), postmenopausal women (aged 49.7 ± 3.4 y; P = 0.009) were characterized by higher fibrinogen levels (by 36.8%), lower C-reactive protein levels (by 36.9%), and lower clot permeability (by 10.5%); also after adjustment for fibrinogen (all P hormone therapy, 24-week oral therapy was associated with higher absorbency of plasma clots by 16% (P Menopause age is associated with the formation of denser fibrin clots. Estrogen plus progestogen therapy has a minor effect on plasma fibrin properties, but leads to the formation of thicker and more branched fibrin fibers, particularly during oral administration.

  1. Mechanical Stability and Fibrinolytic Resistance of Clots Containing Fibrin, DNA, and Histones*

    Science.gov (United States)

    Longstaff, Colin; Varjú, Imre; Sótonyi, Péter; Szabó, László; Krumrey, Michael; Hoell, Armin; Bóta, Attila; Varga, Zoltán; Komorowicz, Erzsébet; Kolev, Krasimir

    2013-01-01

    Neutrophil extracellular traps are networks of DNA and associated proteins produced by nucleosome release from activated neutrophils in response to infection stimuli and have recently been identified as key mediators between innate immunity, inflammation, and hemostasis. The interaction of DNA and histones with a number of hemostatic factors has been shown to promote clotting and is associated with increased thrombosis, but little is known about the effects of DNA and histones on the regulation of fibrin stability and fibrinolysis. Here we demonstrate that the addition of histone-DNA complexes to fibrin results in thicker fibers (increase in median diameter from 84 to 123 nm according to scanning electron microscopy data) accompanied by improved stability and rigidity (the critical shear stress causing loss of fibrin viscosity increases from 150 to 376 Pa whereas the storage modulus of the gel increases from 62 to 82 pascals according to oscillation rheometric data). The effects of DNA and histones alone are subtle and suggest that histones affect clot structure whereas DNA changes the way clots are lysed. The combination of histones + DNA significantly prolongs clot lysis. Isothermal titration and confocal microscopy studies suggest that histones and DNA bind large fibrin degradation products with 191 and 136 nm dissociation constants, respectively, interactions that inhibit clot lysis. Heparin, which is known to interfere with the formation of neutrophil extracellular traps, appears to prolong lysis time at a concentration favoring ternary histone-DNA-heparin complex formation, and DNase effectively promotes clot lysis in combination with tissue plasminogen activator. PMID:23293023

  2. Effect of exercise training on clot strength in patients with peripheral artery disease and intermittent claudication: An ancillary study.

    Science.gov (United States)

    Mauer, Karin; Exaire, J Emilio; Stoner, Julie A; Saucedo, Jorge F; Montgomery, Polly S; Gardner, Andrew W

    2015-01-01

    Patients with peripheral artery disease have walking impairment, greater thrombotic risk, and are often treated with exercise training. We sought to determine the effect of a 3-month-long exercise program on clot strength among patients with peripheral artery disease and intermittent claudication. Twenty-three symptomatic peripheral artery disease patients were randomly assigned to a walking exercise program or to an attention control group who performed light resistance exercise. We investigated the effect of exercise training on clot strength and time to clot formation was assessed by thromboelastography. After 3 months of exercise, clot strength (maximal amplitude) and time to clot formation (R) did not change significantly from baseline, even after improvements in claudication onset time (p < 0.01) and peak walking time (p < 0.05). Furthermore, changes in clot formation parameters were not significantly different between groups. Among the 10 individuals demonstrating a reduction in clot strength (reduced maximal amplitude), one was a smoker (10%) compared to 9 of 13 non-responders (69%) whose maximal amplitude was unchanged or increased (p = 0.0097). In this ancillary study, a 12-week walking program improved ambulatory function in peripheral artery disease patients with claudication, but does not modify clot strength or time to clot formation. Larger studies are needed to confirm these hypothesis generating findings and to determine whether a different amount or type of exercise may induce a change in clotting in this patient population.

  3. Effect of exercise training on clot strength in patients with peripheral artery disease and intermittent claudication: An ancillary study

    Directory of Open Access Journals (Sweden)

    Karin Mauer

    2015-03-01

    Full Text Available Objectives: Patients with peripheral artery disease have walking impairment, greater thrombotic risk, and are often treated with exercise training. We sought to determine the effect of a 3-month-long exercise program on clot strength among patients with peripheral artery disease and intermittent claudication. Methods: Twenty-three symptomatic peripheral artery disease patients were randomly assigned to a walking exercise program or to an attention control group who performed light resistance exercise. We investigated the effect of exercise training on clot strength and time to clot formation was assessed by thromboelastography. Results: After 3 months of exercise, clot strength (maximal amplitude and time to clot formation (R did not change significantly from baseline, even after improvements in claudication onset time (p < 0.01 and peak walking time (p < 0.05. Furthermore, changes in clot formation parameters were not significantly different between groups. Among the 10 individuals demonstrating a reduction in clot strength (reduced maximal amplitude, one was a smoker (10% compared to 9 of 13 non-responders (69% whose maximal amplitude was unchanged or increased (p = 0.0097. Conclusion: In this ancillary study, a 12-week walking program improved ambulatory function in peripheral artery disease patients with claudication, but does not modify clot strength or time to clot formation. Larger studies are needed to confirm these hypothesis generating findings and to determine whether a different amount or type of exercise may induce a change in clotting in this patient population.

  4. Structure, Employment and Performance in Biotech Firms

    DEFF Research Database (Denmark)

    Valentin, Finn; Dahlgren, Johan Henrich; Lund Jensen, Rasmus

    2006-01-01

    .g. universities, firms and venture capital. That makes DDFs a sensitive "seismograph" for the ability of the Danish innovation system to foster new science-based technologies.Key words: Employment, Biotechnology, Firm size distribution, Industry structure,Firm performanceJEL Codes: J21, L11, L22, L25, L65, O57......This report studies employment effects associated with the adoption of modern biotechnology in Danish industry. In this context we also examine industry structure, patterns of job creation, key outputs such as patents and the pipeline of projects in clinical trials. To see the development of Danish...... a segment of Drug Discovery Firms (DDFs), which almost exclusively are based on capabilities in biotech research. This delimitation gives the advantage of studying a homogenous segment of firms. At the same time, this segment of biotech research firms is an informative indicator of the ability of the Danish...

  5. Does Labor Diversity Affect Firm Performance?

    DEFF Research Database (Denmark)

    Pytlikova, Mariola; Pozzoli, Dario; Parrotta, Pierpaolo

    Using an employer-employee dataset, we analyze how diversity in cultural background, skills and demographic characteristics affects total factor productivity (TFP) of firms in Denmark. Implementing structural estimation of firms’ production function, we find evidence that labor diversity in skills...... costs connected to a more demographically and culturally diverse workforce, counteract the positive effects of diversity on firm TFP, coming from creativity and knowledge spillovers. However, we find that ethnic diversity is valuable for firms operating in industries characterized by above-average trade....../education significantly enhances firm performance as measured by firm TFP. Conversely, diversity in demographics and ethnicity brings mixed results – both dimensions of workforce diversity have either no or negative effects on firm TFP. Hence, it seems as if the negative effects, coming from communication and integration...

  6. Women in Top Management and Firm Performance

    DEFF Research Database (Denmark)

    Smith, Nina; Smith, Valdemar; Verner, Mette

    The purpose of this study is to present new evidence on the relationship between gender diversity in management and firm performance. According to corporate governance literature, board diversity is expected to affect firm performance. Using a large data set with more than 10000 time-observations......The purpose of this study is to present new evidence on the relationship between gender diversity in management and firm performance. According to corporate governance literature, board diversity is expected to affect firm performance. Using a large data set with more than 10000 time......-observations for all Danish firms with more than 50 employees over the period 1994-2003, the analysis suggests that the proportion of women in top management jobs has from none to positive influence on firm performance. However, the results show that the strength of the effects of women in top management depends...

  7. How does firm performance influence market orientation?

    DEFF Research Database (Denmark)

    Sørensen, Hans Eibe; Stieglitz, Nils

    This paper contributes by investigating how firm performance influences its market orientation. We draw on the aspiration-level model from the behavioral theory of the firm to develop testable propositions that substantiate and extend prior market orientation research. Specifically, we address how...... performance influences firms' market-oriented search behavior (responsive or proactive) and the allocation of attention (customer and competitor orientation) as well as the formation of aspiration levels. Research and managerial implications are discussed....

  8. Agglomeration Premium and Trading Activity of Firms

    OpenAIRE

    Gabor Bekes; Peter Harasztosi

    2010-01-01

    Firms may benefit from proximity to each other due to the existence of several externalities. The productivity premia of firms located in agglomerated regions an be attributed to savings and gains from external economies. However, the capacity to absorb information may depend on activities of the firm, such as involvement in international trade. Importers, exporters and two-way traders are likely to employ a different bundle of resources and be organised differently so that they would appreci...

  9. Towards a developing country firm perspective

    OpenAIRE

    Schaumburg-Müller, Henrik; Pottenger, Eugene; Hansen, Michael W.

    2007-01-01

    Changes of the global economy have led to a much deeper integration of firms from developing countries. Multinational corporations are increasingly using offshore-outsourcing to maintain competitiveness and market shares. While the implications of this trend has been studied from the point of view of the multinational firm and its home economy, far less attention has been paid to the developing country firm participating in the outsourcing arrangement and its strategic options. From this poin...

  10. Employee Spinouts, Social Networks, and Family Firms

    OpenAIRE

    Rauch, James E.

    2013-01-01

    Recently collected data show that, within any manufacturing industry, vertically integrated firms tend to have larger, higher productivity plants, account for the bulk of sales, and also sell externally most of the inputs they produce. In a weak contracting environment characteristic of developing countries, vertically integrated firms are vulnerable to employee "spinouts": managers of input divisions can start their own firms, making customized inputs formerly provided internally subject to ...

  11. Firm Size Distribution in Fortune Global 500

    Science.gov (United States)

    Chen, Qinghua; Chen, Liujun; Liu, Kai

    By analyzing the data of Fortune Global 500 firms from 1996 to 2008, we found that their ranks and revenues always obey the same distribution, which implies that worldwide firm structure has been stable for a long time. The fitting results show that simple Zipf distribution is not an ideal model for global firms, while SCL, FSS have better fitting goodness, and lognormal fitting is the best. And then, we proposed a simple explanation.

  12. The Internationalisation of Service Firms

    DEFF Research Database (Denmark)

    Blagoeva, Denitsa Hazarbassanova

    Dougal and Baume, 2009), some - that they are not (e.g., Terpstra and Yu, 1988). What we do know is that services are very important. They generate roughly 80% of GDP in the United States and the European Union, and the proportion is well over 50% in most countries, industrial and developing alike (International...... ones, looking at descriptive service characteristics nor industry effects, but on the way they create value. Why and how are service firms different? and What are the drivers behind their internationalisation? are the questions motivating this PhD project. It explores if the value creation...... specificities may be universal axes around which all MNCs, both manufacturing and service ones, configure themselves internally and externally across geographic locations. We do not in fact know that services are different from manufacturing - some empirical evidence suggests they are (e.g. Laanti, Mc...

  13. Complementary effect of fibrinogen and rFVIIa on clotting ex vivo in Bernard-Soulier syndrome and combined use during three deliveries

    DEFF Research Database (Denmark)

    Palsson, Ragnar; Vidarsson, Brynjar; Gudmundsdottir, Brynja R

    2014-01-01

    Women with Bernard-Soulier syndrome (BSS) are considered to be at high risk of serious bleeding during childbirth. Due to the frequently occurring platelet transfusion refractoriness, alternative prophylactic therapy is required. Using rotational thromboelastometry, we evaluated the whole blood...... coagulation profile of a pregnant woman with BSS before and after spiking ex vivo with different concentrations of recombinant activated factor VII (rFVIIa) and fibrinogen. As experiments suggested improved clotting with clinically applicable concentrations of both agents in a complementary manner...... effects were observed during these three deliveries. Our observations suggest that rFVIIa combined with fibrinogen may provide a beneficial clinical hemostatic effect partly by separate but complementary mechanisms....

  14. EAS Test Firm Accrediting Bodies (TFAB)

    Data.gov (United States)

    Federal Communications Commission — EAS (Equipment Authorization System). The accreditation bodies for testing laboratories are referred to as Test Firm Accrediting Bodies (TFABs). They are responsible...

  15. Shared vision promotes family firm performance

    Science.gov (United States)

    Neff, John E.

    2015-01-01

    A clear picture of the influential drivers of private family firm performance has proven to be an elusive target. The unique characteristics of private family owned firms necessitate a broader, non-financial approach to reveal firm performance drivers. This research study sought to specify and evaluate the themes that distinguish successful family firms from less successful family firms. In addition, this study explored the possibility that these themes collectively form an effective organizational culture that improves longer-term firm performance. At an organizational level of analysis, research findings identified four significant variables: Shared Vision (PNS), Role Clarity (RCL), Confidence in Management (CON), and Professional Networking (OLN) that positively impacted family firm financial performance. Shared Vision exhibited the strongest positive influence among the significant factors. In addition, Family Functionality (APGAR), the functional integrity of the family itself, exhibited a significant supporting role. Taken together, the variables collectively represent an effective family business culture (EFBC) that positively impacted the long-term financial sustainability of family owned firms. The index of effective family business culture also exhibited potential as a predictive non-financial model of family firm performance. PMID:26042075

  16. Shared vision promotes family firm performance.

    Science.gov (United States)

    Neff, John E

    2015-01-01

    A clear picture of the influential drivers of private family firm performance has proven to be an elusive target. The unique characteristics of private family owned firms necessitate a broader, non-financial approach to reveal firm performance drivers. This research study sought to specify and evaluate the themes that distinguish successful family firms from less successful family firms. In addition, this study explored the possibility that these themes collectively form an effective organizational culture that improves longer-term firm performance. At an organizational level of analysis, research findings identified four significant variables: Shared Vision (PNS), Role Clarity (RCL), Confidence in Management (CON), and Professional Networking (OLN) that positively impacted family firm financial performance. Shared Vision exhibited the strongest positive influence among the significant factors. In addition, Family Functionality (APGAR), the functional integrity of the family itself, exhibited a significant supporting role. Taken together, the variables collectively represent an effective family business culture (EFBC) that positively impacted the long-term financial sustainability of family owned firms. The index of effective family business culture also exhibited potential as a predictive non-financial model of family firm performance.

  17. Shared Vision promotes family firm performance

    Directory of Open Access Journals (Sweden)

    John Edward Neff

    2015-05-01

    Full Text Available A clear picture of the influential drivers of private family firm performance has proven to be an elusive target. The unique characteristics of private family owned firms necessitate a broader, non-financial approach to reveal firm performance drivers. This research study sought to specify and evaluate the themes that distinguish successful family firms from less successful family firms. In addition, this study explored the possibility that these themes collectively form an effective organizational culture that improves longer-term firm performance. At an organizational level of analysis, research findings identified four significant variables: Shared Vision (PNS, Role Clarity (RCL, Confidence in Management (CON, and Professional Networking (OLN that positively impacted family firm financial performance. Shared Vision exhibited the strongest positive influence among the significant factors. In addition, Family Functionality (APGAR, the functional integrity of the family itself exhibited a significant supporting role. Taken together, the variables collectively represent an effective family business culture (EFBC that positively impacted the long-term financial sustainability of family owned firms. The index of effective family business culture also exhibited potential as a predictive non-financial model of family firm performance.

  18. Industrial environmental practices in Polish Firms

    DEFF Research Database (Denmark)

    Kræmer, Trine Pipi

    , and environment. The five case firms all had a Communist past. The firms represent three different industrial sectors; i.e. textile, energy, and publishing and printing industries. Furthermore, the firms are both private and state owned as well as in the process of privatisation.......The study investigates how discursive developments in Poland interact with industrial environmental practices in five production firms. The analysis of the discursive development covers the period from the end of World War I to the turn of the century. The areas in focus are identity, industry...

  19. The innovative behaviour of tourism firms

    DEFF Research Database (Denmark)

    Sundbo, Jon; Orfila-Sintes, Francina; Sørensen, Flemming

    2007-01-01

    systems. The article suggests that large size, professionalism, but also entrepreneurship among small tourism firms are important determinants of innovation. Varied innovation networks are another determinant as are supportive innovation systems. These determinants favour Spanish firms, which are more...... innovative than Danish ones. In the final section, policy recommendations are presented.......Tourism firms operate in a competitive sector where innovating is often a condition for survival. This article presents a theoretical framework for understanding tourist firms’ innovative behaviour and innovation systems in tourism. The innovativeness of tourism firms and its determinants...

  20. ARE SMALL-FIRM CLUSTERS EMERGENT PHENOMENA? EVIDENCE FROM ZIMBABWE’S SMALL FURNITURE- MANUFACTURING FIRMS

    Directory of Open Access Journals (Sweden)

    Godfrey MUPONDA

    2014-07-01

    Full Text Available The purpose of this study was to explore the reasons behind the rapid growth and apparent dynamism of Zimbabwe’s small-firm industrial clusters. The hypothesis behind the study was that these small-firm clusters are emergent phenomena. The study analysed the capital utilisation techniques of small firms located in a large industrial cluster in order to determine the factors that lead to the collective efficiency of such firms. The study found that, in comparison with large, stock exchange-listed firms, the cluster environment enables the small firm to operate from a relatively small capital base and also to use its capital more efficiently in creating revenues and profits. The individual firm does not have to invest its capital in a large assets base as this is done by a specialised group of firms within the cluster. Thus, the cluster has the characteristics of an emergent phenomenon.

  1. Estimating risk propagation between interacting firms on inter-firm complex network.

    Directory of Open Access Journals (Sweden)

    Hayato Goto

    Full Text Available We derive a stochastic function of risk propagation empirically from comprehensive data of chain-reaction bankruptcy events in Japan from 2006 to 2015 over 5,000 pairs of firms. The probability is formulated by firm interaction between the pair of firms; it is proportional to the product of α-th power of the size of the first bankrupt firm and β-th power of that of the chain-reaction bankrupt firm. We confirm that α is positive and β is negative throughout the observing period, meaning that the probability of cascading failure is higher between a larger first bankrupt firm and smaller trading firm. We additionally introduce a numerical model simulating the whole ecosystem of firms and show that the interaction kernel is a key factor to express complexities of spreading bankruptcy risks on real ecosystems.

  2. Effects of thrombosed vena cava filters on blood flow: flow visualization and numerical modeling.

    Science.gov (United States)

    Stewart, Sandy F C; Robinson, Ronald A; Nelson, Robert A; Malinauskas, Richard A

    2008-11-01

    Inferior vena cava (IVC) filters are used to prevent pulmonary embolism (PE) in patients with deep vein thrombosis for whom anticoagulation is contraindicated. IVC filters have been shown to be effective in trapping embolized clots and preventing PE; however, among the commercially available designs, the optimal balance of clot capture efficiency, clot dissolution, and prevention of to vena cava occlusion is unknown. Clot capture efficiency has been quantified in numerous in vitro studies, in which model clots are released into a mock circulation system, with the relative capture efficiency of various IVC filters analyzed statistically. In general, two-stage filters have been found to be more efficient than one-stage filters. However, other factors may play a role in the ultimate dissolution of clots and in the overall effect of the resulting blood flow on caval vasculature. Clot dissolution has been shown to increase with increasing wall shear stress, while low and oscillating wall shear stresses are known to have a deleterious effect on vessel walls, causing intimal hyperplasia. This paper describes the effect of IVC filters on blood flow, velocity patterns, and wall shear stress by flow visualization and computational fluid dynamics.

  3. A Firm-Specific Analysis of the Exchange-Rate Exposure of Dutch Firms

    NARCIS (Netherlands)

    A. de Jong (Abe); J. Ligterink; V. Macrae

    2002-01-01

    textabstractWe examine the relationship between exchange-rate changes and stock returns for a sample of Dutch firms over 1994-1998. We find that over 50% of the firms are significantly exposed to exchange-rate risk. Furthermore, all firms with significant exchange-rate exposure benefit from a

  4. A firm-specific exposure analyis of the exchange-rate exposure of Dutch firms

    NARCIS (Netherlands)

    de Jong, A.; Ligterink, J.; Macrae, V.

    2006-01-01

    We examine the relationship between exchange-rate changes and stock returns for a sample of Dutch firms over 1994-1998. We find that over 50 per cent of the firms are significantly exposed to exchange-rate risk. Furthermore, all firms with significant exchange-rate exposure benefit from a

  5. 32 CFR 37.1250 - Commercial firm.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Commercial firm. 37.1250 Section 37.1250... REGULATIONS TECHNOLOGY INVESTMENT AGREEMENTS Definitions of Terms Used in This Part § 37.1250 Commercial firm... does a substantial portion of its business in the commercial marketplace. ...

  6. Tax Compliance over the Firm Life Course

    NARCIS (Netherlands)

    Stam, F.C.; Verbeeten, F.H.M.

    2017-01-01

    This article provides a new model of tax compliance over the firm life course, focusing on the dynamics in the underlying motivations and capacities for tax compliance. We review and structure the relevant literature on the early life course of firms: the traditional stages of growth models and a

  7. Architectural firms: workforce, business strategy and performance

    Directory of Open Access Journals (Sweden)

    Adedapo Adewunmi Oluwatayo

    2011-12-01

    Full Text Available The intent of this research was to investigate the relationship between the workforce, business strategy and performance of architectural firms. Data was collected from 92 firms randomly selected from the cities where architectural firms were most concentrated in Nigeria using questionnaires. Hierarchical regression analysis was carried out to investigate the direct and indirect impacts of the workforce of architectural firms on their performance. The findings confirm the significant positive impact. With business strategy controlled, the specific characteristics of the workforce and its management which influenced performance were the number of architects, the work structure, and the age and experience of the principal partners. The impact of the number of non- architecture professionals and staff participation in decision-making on performance was moderated by the business strategy adopted by the firms. The results suggest that workforce characteristics are more important than the management of the workforce in determining performance of architectural firms. This is contrary to the results of previous studies which suggest higher importance of the management. This probably indicates the peculiarity of architectural firm as a professional service firm in the construction industry.

  8. Electronic Commerce, Digital Information, and the Firm.

    Science.gov (United States)

    Rosenbaum, Howard

    2000-01-01

    Discussion of the social context of electronic commerce (ecommerce) focuses on information imperatives, or rules that are critical for ecommerce firms. Concludes with a discussion of the organizational changes that can be expected to accompany the incorporation of these imperatives into the mission and core business processes of ecommerce firms.…

  9. Firm-level volatility and exports

    NARCIS (Netherlands)

    Vannoorenberghe, G.C.L.

    2012-01-01

    This paper shows that the share of exports in the total sales of a firm has a positive and substantial impact on the volatility of its sales. Decomposing the volatility of sales of exporters between their domestic and export markets, I show using an identification strategy based on a firm-specific

  10. Risk Coping by Firms during the Crisis

    NARCIS (Netherlands)

    Guimbert, S; Oostendorp, R.H.

    2016-01-01

    In this paper, we analyze risk coping behavior of Cambodian firms during the global financial crisis. Among various risk coping strategies, we specifically analyze input smoothing (labor, raw materials, or capital). If it is costly to adjust inputs, firms will prefer to smooth the path of adjusting

  11. Psychic Distance, Innovation, and Firm Performance

    NARCIS (Netherlands)

    Azar, Goudarz; Drogendijk, Rian

    2014-01-01

    Previous research suggests that internationalization improves a firm's ability to innovate, but the effect of internationalizing into specific target markets or destinations on the innovation ability of firms has not been fully investigated. This study examined whether the psychic distance between

  12. Managing firm competitiveness in global markets

    NARCIS (Netherlands)

    Gehlhar, M.; Regmi, A.; Stefanou, S.E.; Zoumas, B.

    2006-01-01

    The globalization profile of US food firms is mixed. US sales from foreign direct investment is now over six times the level of exports, while US processed food trade balance has moved from +$9 billion in 1995 to - $7 billion in 2004. Competitive forces drive firms to seek new areas of growth, with

  13. Price Discrimination Bans on Dominant Firms

    NARCIS (Netherlands)

    Bouckaert, J.M.C.; Degryse, H.A.; van Dijk, T.

    2008-01-01

    Competition authorities and regulatory agencies sometimes impose pricing restrictions on firms with substantial market power — the “dominant” firms. We analyze the welfare effects of a ban on behaviour-based price discrimination in a two-period setting where the market displays a competitive and a

  14. Theoretical Perspectives on the Internationalization of Firms

    Science.gov (United States)

    Rask, Morten; Strandskov, Jesper; Hakonsson, Dorthe Dojbak

    2008-01-01

    The purpose of this article is to build a coherent framework of the four main theories relating to the internationalization of firms, in order to facilitate better business teaching and research. Yet, theories of the internationalization of firms are broad and rest on different underlying assumptions. With the purpose of clarifying the potential…

  15. When do German Firms Change their Dividends?

    NARCIS (Netherlands)

    Correia Da Silva, L.; Goergen, M.; Renneboog, L.D.R.

    2002-01-01

    Anecdotal evidence suggests that the dividend policy of German firms is more flexible than the one of their Anglo-American counterparts.This paper analyses the decision to change the dividend for a panel of 221 German firms from 1984 to 1994.The choice of the period of study is motivated by the fact

  16. Human Capital and Wages in Exporting Firms

    DEFF Research Database (Denmark)

    Munch, Jakob Roland; Skaksen, Jan Rose

    This paper studies the link between a firms education level, export performance and wages of its workers. We argue that firms may escape intense competition in international markets by using high skilled workers to differentiate their products. This story is consistent with our empirical results....

  17. internationalisation et nouvelles implantations des firmes

    African Journals Online (AJOL)

    Administrateur

    implantation des firmes multinationales ainsi que des nombreuses extensions possibles du modèle. ... Docteur en science de gestion, Chercheur en stratégie et prospective. ..... firme dans ses choix de filiales et de métiers à intégrer dans la phase.

  18. Explaining firm employment growth : Does location matter?

    NARCIS (Netherlands)

    Hoogstra, GJ; van Dijk, J.

    2004-01-01

    This paper addresses the question to what extent the location of a firm can be regarded as having an influence on the performance of a firm as measured by employment growth. While in theory it is widely acknowledged that 'location' should be considered as a relevant growth determinant, empirical

  19. Uncertainty and growth of the firm

    NARCIS (Netherlands)

    Lensink, R; van Steen, P; Sterken, E

    Using data from a survey of 1,097 small and medium-sized non-listed Dutch firms we investigate the relation between growth of the firm and uncertainty. We focus on the impact of sales uncertainty on various types of investment. We find that sales uncertainty, measured by the conditional variance,

  20. Career Development Programs in Fortune 500 Firms.

    Science.gov (United States)

    Keller, Jack; Piotrowski, Chris

    Career development programs (CDPs) are a rather recent area of study in organizational and industrial psychology. The present study investigated the nature and evaluation of CDPs in Fortune 500 firms. Data were obtained by a mailed questionnaire completed by the firms' human resources directors. Of the 500 companies surveyed, only those 50 that…

  1. Female Directors, Board Committees and Firm Performance

    NARCIS (Netherlands)

    Green, Colin P.; Homroy, Swarnodeep

    A number of studies have found little economic impact of board gender diversity on firm performance. We return to this issue in the context of large European firms. Our contribution is twofold. First, using information on the gender of CEOs children as a source of exogenous variation in female

  2. Trade credit: Elusive insurance of firm growth

    NARCIS (Netherlands)

    Bams, Dennis; Bos, Jaap; Pisa, Magdalena

    2016-01-01

    Firms depend heavily on trade credit. This paper introduces a trade credit network into a structural model of the economy. In an empirical analysis of the model, we find that trade credit is an elusive insurance: as long as a firm is financially unconstrained and times are good, more trade credit

  3. New workplace practices and firm performance:

    DEFF Research Database (Denmark)

    Cristini, Annalisa; Pozzoli, Dario

    Using data from the 2004 Workplace Employee Relations Survey on British establishments and two surveys on manufacturing firms located in the North of Italy, we look at the diffusion of new workplace practices in the two countries and at their impact on the firm's value added. We find...

  4. A serpin released by an entomopathogen impairs clot formation in insect defense system.

    Science.gov (United States)

    Toubarro, Duarte; Avila, Mónica M; Hao, Youjin; Balasubramanian, Natesan; Jing, Yingjun; Montiel, Rafael; Faria, Tiago Q; Brito, Rui M; Simões, Nelson

    2013-01-01

    Steinernema carpocapsae is an entomopathogenic nematode widely used for the control of insect pests due to its virulence, which is mainly attributed to the ability the parasitic stage has to overcome insect defences. To identify the mechanisms underlying such a characteristic, we studied a novel serpin-like inhibitor (sc-srp-6) that was detected in a transcriptome analysis. Recombinant Sc-SRP-6 produced in Escherichia coli had a native fold of serpins belonging to the α-1-peptidase family and exhibited inhibitory activity against trypsin and α-chymotrypsin with Ki of 0.42 × 10(-7) M and 1.22 × 10(-7) M, respectively. Functional analysis revealed that Sc-SRP-6 inhibits insect digestive enzymes, thus preventing the hydrolysis of ingested particles. Moreover, Sc-SRP-6 impaired the formation of hard clots at the injury site, a major insect defence mechanism against invasive pathogens. Sc-SRP-6 does not prevent the formation of clot fibres and the activation of prophenoloxidases but impairs the incorporation of the melanin into the clot. Binding assays showed a complex formation between Sc-SRP-6 and three proteins in the hemolymph of lepidopteran required for clotting, apolipophorin, hexamerin and trypsin-like, although the catalytic inhibition occurred exclusively in trypsin-like. This data allowed the conclusion that Sc-SRP-6 promotes nematode virulence by inhibiting insect gut juices and by impairing immune clot reaction.

  5. Efficient Climate Policy with Internationally Mobile Firms

    International Nuclear Information System (INIS)

    Maestad, O.

    2001-01-01

    A major concern in the design of an incomplete climate agreement is that firms that use fossil fuels intensively may respond to emission regulations by relocating their plants from cooperating to non-cooperating countries. This paper analyses how the cooperating countries might deal with the issue of firm delocation through emission taxes, trade provisions and a localisation subsidy to mobile firms. It is shown that firms should not be induced to stay in the cooperating countries by lowering emission taxes below the Pigouvian tax rate. Incentives to stay should be given partly through trade provisions and partly through a localisation subsidy. A second best solution without localisation subsidies is also discussed. In that case, the efficient emission tax is lower than the Pigouvian tax rate. Finally, the paper discusses the implications of the first best and the second best policy regimes for the pattern of firm localisation. 19 refs

  6. Discrepant coagulation profile in HIV infection: elevated D-dimer but impaired platelet aggregation and clot initiation.

    Science.gov (United States)

    Haugaard, Anna K; Lund, Tamara T; Birch, Carsten; Rönsholt, Frederikke; Trøseid, Marius; Ullum, Henrik; Gerstoft, Jan; Johansson, Per I; Nielsen, Susanne D; Ostrowski, Sisse R

    2013-11-13

    In HIV infection, cardiovascular disease (CVD) has emerged as a clinical problem, and elevated D-dimer has been reported. The pathophysiologic mechanisms underlying this remain unclear. We aimed to investigate whether untreated HIV-infected individuals display evidence of functional coagulopathy and whether this was associated with microbial translocation. The study population consisted of 50 HIV-infected untreated individuals and 50 HIV-infected individuals on combination antiretroviral therapy (cART). Groups were matched for age, sex and current CD4cell count. Coagulation analyses included D-dimer and the functional haemostatic whole blood tests, thromboelastography (TEG) and platelet aggregation (Multiplate, impedance aggregometry). Microbial translocation was assessed by plasma levels of lipopolysaccharide (LPS). A larger proportion of untreated individuals compared with treated individuals had D-dimer above normal reference range (27.7 vs. 2.2%, P = 0.001). In both treated and untreated individuals, delayed clot initiation with TEG R-time above upper reference range (18 and 28%, respectively, both P < 0.001) and TEG angle below lower reference range [14% (P = 0.004) and 24% (P < 0.001), respectively] was found. In untreated individuals, 64.6% had aggregation response below threshold in at least two of four tests compared with 36.7% in treated individuals (P = 0.010). Untreated individuals with increased D-dimer levels were relatively hypercoagulable by thromboelastography. Furthermore, in untreated patients, a negative association between microbial translocation and platelet aggregation was found. Elevated D-dimer in untreated HIV-infected individuals was confirmed. However, in both untreated and treated individuals, reduced platelet aggregation and clot initiation was found. The impact of reduced platelet function in HIV infection and a potential role of microbial translocation warrant further investigation.

  7. Deep Vein Thrombosis (DVT) / Pulmonary Embolism (PE) - Blood Clot Forming in a Vein

    Science.gov (United States)

    ... Recommend on Facebook Tweet Share Compartir Deep Vein Thrombosis and Pulmonary Embolism (DVT/PE) are often underdiagnosed and serious, but preventable medical conditions. Deep vein thrombosis (DVT) is a medical condition that occurs when ...

  8. A feasible strategy for preventing blood clots in critically ill patients with acute kidney injury (FBI)

    DEFF Research Database (Denmark)

    Robinson, Sian; Zincuk, Aleksander; Larsen, Ulla Lei

    2014-01-01

    , and will continue for two years. The primary outcome is the occurrence of venous thromboembolism. Secondary outcomes include anti-factor Xa activity, bleeding, heparin-induced thrombocytopenia, filter lifespan, length of stay, ventilator free days, and mortality. We will also monitor neutrophil gelatinase...

  9. CHROMATOGRAPHY OF BLOOD-CLOTTING FACTORS AND SERUM PROTEINS ON COLUMNS OF DIATOMACEOUS EARTH

    Science.gov (United States)

    Milstone, J. H.

    1955-01-01

    1. In batch adsorptions with prothrombin solutions, hyflo was the weakest adsorbent, standard super-cel intermediate, and filter-cel strongest. Of these three grades of diatomaceous earth, hyflo has the smallest surface area per gram and filter-cel the largest. In parallel breakthrough experiments, a column of standard super-cel had a capacity almost six times that of a hyflo column. 2. After partial removal of impurities by diatomaceous earth, prothrombin preparations contained less thrombokinase, were more stable, and displayed less tendency to form thrombin "spontaneously." Thrombokinase (or its precursor) was removed from a preparation of prothrombin by passage through a filter cake of standard super-cel. The specific activity of the prothrombin was increased; and 62 per cent of the activity was recovered. 3. Prothrombin was adsorbed from an ammonium sulfate solution at pH 5.26 by columns of hyflo or standard super-cel. When eluted by phosphate solutions, the protein moved down the columns more readily at higher pH and higher concentration of phosphate salts, within the pH range 5.0 to 6.6, and within the phosphate range 0.1 to 1.0 M. 4. Thrombin was adsorbed on a column of standard super-cel at pH 5.11. As successive eluents passed through the column, the thrombin emerged between two bands of impurities. The specific activity of the thrombin was raised; and 83 per cent of the activity was recovered. 5. With a column of standard super-cel, and with a series of eluents within the pH range 5.1 to 6.3, total serum proteins were separated into four major bands. About 94 per cent of the protein was recovered. PMID:13242761

  10. Apixaban or Dalteparin in Reducing Blood Clots in Patients With Cancer Related Venous Thromboembolism

    Science.gov (United States)

    2017-12-28

    Cerebral Vein Thrombosis; Deep Vein Thrombosis; Gonadal Thrombosis; Hepatic Thrombosis; Malignant Neoplasm; Mesenteric Thrombosis; Metastatic Malignant Neoplasm; Portal Vein Thrombosis; Pulmonary Embolism; Renal Vein Thrombosis; Splenic Thrombosis; Venous Thromboembolism

  11. Views of CEOs on Firm Performance

    Directory of Open Access Journals (Sweden)

    Dario Berginc

    2014-11-01

    Full Text Available Researching the managerial perspective of performance can contribute to a better understanding of firm performance, and offer a valuable contribution to research on objective performance measurement. The aim of this article is to examine how managers evaluate firm performance and which factors, in their opinion, have the biggest influence on performance. We particularly wanted to investigate the influence of top management and owners on firm performance. We conducted a qualitative study among the CEOs of some of the most successful Slovenian firms. The results show that CEOs connect positive performance with long-term growth and satisfying the needs of key stakeholders (employees, customers and owners, but short-term positive financial performance represents the basic foundation. The second most important factor is a united top management, capable of generating new ideas and acting as a role model to employees. This can lead to a higher degree of engagement by employees and a better understanding of the firm's goals. Owners can contribute to a positive firm performance with their active, strategic and long-term orientation, and with their ability to set clear goals and to trust top management in the long run. Another important factor that influences firm performance is the ownership structure. In the opinion of CEOs, dominant and private ownership has a more positive impact on firm performance than dispersed and state ownership. The present research findings provide several examples of good and bad practice, and highlight opportunities for further research, from an in-depth study of individual factors of firm performance to the search for a more comprehensive model of performance factors, based on a larger sample of CEOs and other managers.

  12. Contribution of a portable air plasma torch to rapid blood coagulation as a method of preventing bleeding

    International Nuclear Information System (INIS)

    Kuo, S P; Chen, C Y; Fan, H W; Tarasenko, O; Scott, A; Lahiani, M; Alusta, P; Chang, J; Popovic, S; Drake, J D; Nikolic, M

    2009-01-01

    The effectiveness and mechanism of a low temperature air plasma torch in clotting blood are explored. Both blood droplets and smeared blood samples were used in the tests. The treated droplet samples reveal how blood clotting depends on the distance at which the torch operated, and for how long the droplets have been exposed to the torch. Microscopy and cell count of smeared blood samples shed light on dependencies of erythrocyte and platelet counts on torch distance and exposure time. With an increase of torch distance, the platelet count of treated blood samples increases but is less than that of the control. The flux of reactive atomic oxygen (RAO) and the degree of blood clotting decreased. With an increase of exposure time, platelet count of treated samples decreased, while the degree of clot increased. The correlation among these dependencies and published data support a blood clotting mechanism that RAO as well as other likely reactive oxygen species generated by the plasma torch activate erythrocyte-platelets interactions and induces blood coagulation.

  13. Banking Firm, Equity and Value at Risk

    Directory of Open Access Journals (Sweden)

    Udo Broll

    2012-12-01

    Full Text Available The paper focuses on the interaction between the solvency probability of a banking firm and the diversification potential of its asset portfolio when determining optimal equity capital. The purpose of this paper is to incorporate value at risk (VaR into the firm-theoretical model of a banking firm facing the risk of asset return. Given the necessity to achieve a confidence level for solvency, we demonstrate that diversification reduces the amount of equity. Notably, the VaR concept excludes a separation of equity policy and asset-liability management.

  14. Commercialization of Innovations and Firm Performance

    DEFF Research Database (Denmark)

    Madsen, Erik Strøjer; Smith, Valdemar

    The decision on investment in R&D is very important and highly risky for firms' performance and survival in their business. This paper focuses on the commercialization of firms' investment in innovation and how these decisions affect their performance. The study uses a large innovation survey...... in innovation and marketing making R&D and marketing complements in their investment decision. However, there is only week evidence for the hypothesis that commercialization of innovations also creates more value for the firms in the short run....

  15. Commercialization of Innovations and Firm Performance

    DEFF Research Database (Denmark)

    Madsen, Erik Strøjer; Smith, Valdemar

    The decision on investment in R&D is very important and highly risky for firms' performance and survival in their business. This paper focuses on the commercialization of firms' investment in innovation and how these decisions affect their performance. The study uses a large innovation survey...... in innovation and marketing making R&D and marketing complements in their investment decision. However, there is only week evidence for the hypothesis that commercialization of innovations also creates more value for the firms in the short run.  ...

  16. Do Treasure Islands Create Firm Value?

    DEFF Research Database (Denmark)

    Choy, Siu Kai; Lai, Tat-kei

    subsidiaries. After this event, there was a 0.9% drop in cumulative abnormal returns among the non-financial firms (corresponding to about £9 billion in market capitalization), more so for better-governed firms and those with larger shares of subsidiaries in tax havens. We find some evidence that government......On October 11, 2011, a non-governmental organization called ActionAid published a report condemning the FTSE 100 firms for holding an unusually large number of subsidiaries in tax havens. Urging the government to take appropriate actions, the report raised the firms’ costs of holding tax haven...

  17. Paradoxes and Innovation in Family Firms

    DEFF Research Database (Denmark)

    Ingram, Amy E.; Lewis, Marianne W.; Barton, Sid

    2016-01-01

    Scholars stress that family firms are inherently paradoxical, and that tensions, such as tradition versus change, family liquidity versus business growth, and founder control versus successor autonomy, can both inhibit and foster innovation. Further, theorists propose that firms led by paradoxica...... indicate that paradoxical tensions may stymie innovative behavior, but that leaders' paradoxical thinking is positively related to innovative behavior....... thinkers are more likely to manage these tensions and fuel innovative behavior. Leveraging family business and organizational paradox literatures, this multi-stage exploratory study develops measures of paradoxical tensions and paradoxical thinking in family firms, and tests these propositions. Findings...

  18. Pro-social Motivation beyond Firm Boundaries

    DEFF Research Database (Denmark)

    Foss, Nicolai; Milagres, Rosileia

    2014-01-01

    An influential body of literature in macro-management research (notably, organization theory and strategic management) associates pro-social motivation solely with firm-like organizations, suggesting that such motivation cannot thrive under more market-like arrangements. We question this argument...... on theoretical, as well as empirical, grounds. As to the latter, we discuss the specific case of a network of firms in Brazil, the Genolyptus network. We argue that this particular network manifests strong pro-social motivations. This implies that pro-social motivations may thrive beyond corporate boundaries......-social motivations in non-firm governance structures....

  19. Determinants of Productivity of Ukrainian Firms

    Directory of Open Access Journals (Sweden)

    Cieślik Andrzej

    2017-03-01

    Full Text Available This paper examines the determinants of total factor productivity (TFP of Ukrainian firms in manufacturing and services, using micro-level data for the years 2005 and 2013. We first estimate regressions for the pooled dataset for the manufacturing and service sectors jointly, and then separately for each sector. Our empirical results show a positive link between the total factor productivity, intangible assets, capital intensity, firm size, competition in the industry, ownership status, and firm internationalization (exports and imports. In addition, we find that the determinants of productivity differ among the sectors and years of our sample.

  20. Endogenous network of firms and systemic risk

    Science.gov (United States)

    Ma, Qianting; He, Jianmin; Li, Shouwei

    2018-02-01

    We construct an endogenous network characterized by commercial credit relationships connecting the upstream and downstream firms. Simulation results indicate that the endogenous network model displays a scale-free property which exists in real-world firm systems. In terms of the network structure, with the expansion of the scale of network nodes, the systemic risk increases significantly, while the heterogeneities of network nodes have no effect on systemic risk. As for firm micro-behaviors, including the selection range of trading partners, actual output, labor requirement, price of intermediate products and employee salaries, increase of all these parameters will lead to higher systemic risk.

  1. Firm-Specific Foreign Exchange Exposure Identification

    DEFF Research Database (Denmark)

    Aabo, Tom; Brodin, Danielle

    2014-01-01

    Previous studies have used the stock market approach to find the aggregate number of (firms with) foreign exchange exposures in a given country, region, or industry. Methodologies have differed in many aspects but two of the most basic differences relate to observation frequency and the choice......-financial firms and find limited consistency in the detected exchange rate exposures when altering methodology in terms of observation frequency and choice of market index. The results put a question mark to the validity of the stock market approach for exchange rate exposure identification at the firm...

  2. Agility in a small software firm

    DEFF Research Database (Denmark)

    Schmidt, Thomas; Mathiassen, Lars

    2009-01-01

    Danish software firm, TeachTech Inc., through the lens of Haeckel's sense-and-respond approach. Our analysis suggests that: the firm has appropriate sense-and-respond cycles, but improving process modularity and human resource flexibility, could increase its ability to respond faster and more effectively......; the firm focuses on specific business goals, but these are not clearly explicated and expressed as empowering governing values enabling a quick and coordinated response; complex and demanding challenges are related to dynamically reassigning commitments and the supporting mechanisms are insufficient...

  3. FOOD ENTREPRENEUR SUSTAINABLE ORIENTATION AND FIRM PRACTICES

    Directory of Open Access Journals (Sweden)

    Mark A. Gagnon

    2016-10-01

    Full Text Available This exploratory research examines the relationship between food entrepreneur sustainable orientation, mindset and firm sustainable practices in a mixed methods format. In particular we seek to address if entrepreneur behavior and firm practices are congruent with founding entrepreneur espoused support of sustainability. Our survey findings with thirty specialty food entrepreneurs suggest tenuous empirical support for the relationship of entrepreneur sustainable orientation, mindset and firm sustainable practices. However our qualitative results indicate positive relationships between sustainable orientation, mindset and practices. Evidence from this work highlights the critical role of founding entrepreneurs for successful implementation of sustainability along its multiple fronts including profitability.

  4. ADENOIDECTOMY/TONSILLECTOMY – Is the Clotting Profile ...

    African Journals Online (AJOL)

    Dr. Paul Adekunle Onakoya

    findings that could suggest bleeding disorders, values of prothrombin/activated partial thromboplastin time and ... history, complete blood count, platelet level and .... References. 1. Hartnick CJ, Ruben RJ. Preoperative coagulation studies prior to tonsillectomy. Arch Otolaryngol. Head Neck Surg 2000; 126: 684 – 688. 2.

  5. THE EFFECT OF FIRM PERFORMANCE, LEVERAGE, FIRM SIZE, AND FIRM GROWTH ON AGENCY COST OF TRADING COMPANY IN INDONESIA, MALAYSIA, AND THAILAND: RESEARCH PERIOD OF 2009 – 2013

    OpenAIRE

    Hamidah Hamidah; Ari Wicaksono; Gatot Nazir Ahmad

    2017-01-01

    In this study,the author investigate the relationship of firm performance, leverage, firm size, and firm growth on the agency cost. In the company’s life, there are several holders an important role in the company itself. Agency theory explains that there are two parties to a company, the agent and principal.Researcher use firm performance, leverage, firm size, and firm growth as the independent variables. Researcher use the operational expenses ratio as proxy of agency cost. The high firm pe...

  6. Source of finance, growth and firm size: Evidence from China

    OpenAIRE

    Du, Jun; Girma, Sourafel

    2009-01-01

    Using a comprehensive firm-level dataset spanning the period 1998-2005, this paper provides a thorough investigation of the relationship between firm size, total factor productivity growth and financial structure in China, controlling for the endogeneity of the latter. Generally, it finds financing source matters for firms of different size, and the extent to which financing source matters for firm growth is greater for small firms than big firms. Self-raised finance appears to be most effect...

  7. Taxing the Financially Integrated Multinational Firm

    DEFF Research Database (Denmark)

    Johannesen, Niels

    the perspective of a small, open economy. This finding contrasts the standard result that the optimal source based capital tax is zero. Intuitively, to the extent that multinational firms finance investment in country i with loans from affiliates in country j, the burden of corporate taxes in the latter country......This paper develops a theoretical model of corporate taxation in the presence of financially integrated multinational firms. Under the assumption that multinational firms at least partly use internal loans to finance foreign investment, we find that the optimal corporate tax rate is positive from...... partly fall on investment and thus workers in the former country. This tax exporting mechanism introduces a scope for corporate taxes, which is not present in standard models of international taxation. Accounting for the internal capital markets of multinational firms thus represents a way to resolve...

  8. Technology Driven Organizational Structure of the Firm

    NARCIS (Netherlands)

    van den Brink, J.R.; Ruys, P.H.M.

    2008-01-01

    We model a corporate firm with a variable internal organizational structure that adapts to various degrees of technological cooperation. The entrepreneur determines the organizational structure that maximizes profits under participation constraints. Wages are determined by an internal cooperative

  9. Green Shipping Practices of Shipping Firms

    Directory of Open Access Journals (Sweden)

    Young-Tae Chang

    2017-05-01

    Full Text Available The primary objective of this study is to provide an empirical research using structural equation modeling to identify the factors that motivate shipping firms to adopt green shipping practices (GSP. Furthermore, it also examines if adopting GSP can enhance the shipping firms’ environmental and productivity performance. The findings show that shipping firms are motivated to adopt GSP mostly by industrial norms set by institutionalized associations. They are also motivated by customers’ demand for environmental friendliness and their own strategy to make good image. Unlike our expectation, government regulations and international environmental laws are not significant in influencing shipping firms to adopt GSP. Moreover, adoption of green shipping practices can improve the environmental and productivity performance of the shipping firms.

  10. New Environmental Practices in Polish Production Firms

    DEFF Research Database (Denmark)

    Kræmer, Trine Pipi

    2002-01-01

    Based on five case studies in Poland, the paper discusses, how a specific environmental policy influences the firms? industrial environmental practices. The study illustrates, how the Polish environmental policy, dominated by environmental charges on emissions, is extremely effective in improving...

  11. Judo Economics in Markets with Multiple Firms

    Directory of Open Access Journals (Sweden)

    Daniel Cracau

    2014-01-01

    Full Text Available We study a sequential Bertrand game with one dominant market incumbent and multiple small entrants selling homogeneous products. Whilst the equilibrium for the case of a single entrant is well known from Gelman and Salop (1983, we derive properties of the N-firm equilibrium and present an algorithm that can be used to calculate this equilibrium. The algorithm is based on a recursive manipulation of polynomials that derive the optimisation problem that each of the market entrants is facing. Using this algorithm we derive the exact equilibrium for the cases of two and three small entrants. For more than three entrants only approximate results are possible. We use numerical results to gain further understanding of the equilibrium for an increasing number of firms and in particular for the case where N diverges to infinity. Similarly to the two-firm Judo equilibrium, we see that a capacity limitation for the small firms is necessary to achieve positive profits.

  12. EAS 2.948 Listed Test Firms

    Data.gov (United States)

    Federal Communications Commission — EAS (Equipment Authorization System). The following firms have submitted the information required by Section 2.948 of the FCC Rules for measuring devices subject to...

  13. Small Firm Internationalization, Innovation, and Growth

    NARCIS (Netherlands)

    Boermans, M.A.; Roelfsema, H.J.

    2016-01-01

    This paper studies the effect of internationalization on innovation and firm performance (employment growth and sales growth) taking the interdependencies among the variables into account. Given the potential endogeneity, this study uses theory-driven instrumental variables and structural equation

  14. Choice of Ownership Structure and Firm Performance

    DEFF Research Database (Denmark)

    Jones, Derek C; Kalmi, Panu; Mygind, Niels

    2003-01-01

    explains subsequentownership changes, especially away from employee ownership; (iii) allocation of ownershipdepends on the pre-privatisation origin and location of the firm, and these factors also influencesubsequent ownership changes. Finally we compare our findings with those achieved by usingmore...

  15. The process of International Expansion of Firms

    OpenAIRE

    Fazal, Imran

    2009-01-01

    A firm may enter into the foreign market by different modes. Firm could operate in the foreign country by physical appearance in the host country such as establishing factories and joint venture. In contrast, some mode could be expands in the foreign country while operate from home country such as exporting. Exporting mode is very common to expand internationally. It required low investment relative to other modes such as joint venture and establishing factories in the foreign country. By app...

  16. Innovation strategies of Mexican pharmaceutical firms

    OpenAIRE

    José Luis Solleiro; Roberto E. López Martínez; Gabriela Sánchez; Yissel Inurrueta; Ana L. Sánchez; Antonia Terán; Jorge I. Castillo

    2010-01-01

    Mexican pharmaceutical market is the most important in Latin America and a significant number of global firms have different business activities in this country: production, licensing of patents, alliances with Mexican firms, distribution facilities or partnerships, etc. In terms of innovation, global pharmaceutical industry has passed through structural changes mainly of technological and institutional nature. These changes have been influential along the whole value chain and have triggered...

  17. Firm Performance-A Social Networks Perspective

    OpenAIRE

    Jane Tung

    2012-01-01

    Problem statement: The study aims to offer a discussion on social networks and their effect on firm performance and also to illustrate the ways by which the firms utilize social capital through networks. Approach: The literature review and arguments were conducted to provide a systematic discussion of social networks and their effects. Results: The study had provided with a detailed understanding of the strategies that had been found to be highly significant in successful organizational perf...

  18. Dual Headquarters Involvement in Multibusiness Firms

    DEFF Research Database (Denmark)

    Nell, Phillip Christopher; Kappen, Philip; Dellestrand, Henrik

    development projects of subsidiaries. Analyses of 85 innovation development projects reveal that dual innovation importance (innovation that is important for the division and the rest of the firm), and dual dual embeddedness (innovating subsidiary is embedded both within the division and in the rest...... of the firm) lead to greater dual headquarters involvement, especially when the innovation development network is large. The results contribute to the literature on complex parenting and theory of selective headquarters involvement....

  19. Intangible assets and firm-level productivity

    OpenAIRE

    Crass, Dirk; Peters, Bettina

    2014-01-01

    Firms invest huge amounts into intangible assets. This paper explores to which extent different kinds of intangible assets are conducive to firm-level produc- tivity. Our study contributes to the literature by simultaneously comparing productivity effects of innovative capital, human capital, branding capital and organizational capital and testing whether complementarity or substitutabil- ity exists between different intangible assets. Using panel data for the period 2006-20...

  20. Human Capital and New Firm Formation

    OpenAIRE

    Karlsson, Charlie; Backman, Mikaela

    2008-01-01

    This paper investigates the impact human capital has on new firm formation, traditionally expected to have a positive influence. Individuals are attracted to regions with a stimulating atmosphere and tend to stay within the same region. Since human capital is partly spatially bounded, the size of municipality accessibility to human capital is expected to have a larger impact than intra-regional and inter-regional interaction. The empirical analysis is based on data on new firm formation at th...

  1. Markups and Firm-Level Export Status

    DEFF Research Database (Denmark)

    De Loecker, Jan; Warzynski, Frederic

    and export behavior using plant-level data. We find that i) markups are estimated significantly higher when controlling for unobserved productivity, ii) exporters charge on average higher markups and iii) firms' markups increase (decrease) upon export entry (exit).We see these findings as a first step...... in opening up the productivity-export black box, and provide a potential explanation for the big measured productivity premia for firms entering export markets....

  2. Cost Focussed Firms and Internet Usage

    OpenAIRE

    Joanne Loundes

    2002-01-01

    This paper looks at Internet usage by Australian firms that have a cost focussed competitive strategy. The data source for this analysis is the Melbourne Institute Business Survey, conducted by the Melbourne Institute of Applied Economic and Social Research. The survey was conducted in late 2001, and targeted large Australian firms. Instrumental variables estimation found that cost-focussed organizations utilised the Internet more intensively for both internal organizational activities and ex...

  3. The Internationalization of Creative Professional Service Firms

    OpenAIRE

    McQuillan, Deirdre

    2013-01-01

    The need to understand the internationalization process of the organization is a field of increasing contemporary interest due to greatly intensified trade flows between nations over the last two decades. While traditionally internationalization was generally pursued by manufacturing firms, service organizations, including creative professional service firms (creative PSFs) such as architects now commonly internationalize their activities. However, theory to date continues to focus on traditi...

  4. The innovative behaviour of tourism firms

    OpenAIRE

    Odília A. M. Meneses; Aurora A C Teixeira

    2011-01-01

    Tourism is a growing and an extremely competitive sector. To be competitive, tourism firms need do innovate, responding to the more and more demanding tourist. Nonetheless, research on this field is limited and insufficient. In Portugal, the tourism sector is a highly strategic sector for the Portuguese economy, but there is no evidence on how Portuguese tourism firms innovate. This paper presents a thesis proposal with the aim to provide empirical evidence of the innovative behaviour of Port...

  5. Optimal debt maturity and firm investment

    OpenAIRE

    Juggler, Joachim; Schott, Immo

    2016-01-01

    This paper introduces a maturity choice to the standard model of firm financing and investment. Longterm debt renders the optimal firm policy time-inconsistent. Lack of commitment gives rise to debt dilution. This problem becomes more severe during downturns. We show that cyclical debt dilution generates the observed counter-cyclical behavior of default, bond spreads, leverage, and debt maturity. It also generates the pro-cyclical term structure of corporate bond spreads. Debt dilution render...

  6. Bostering firm growth : Kasvu Open 2014

    OpenAIRE

    Helin, Erik; Kangasvieri, Teemu

    2015-01-01

    There has been a significant increase in SME growth research in recent years as its macroeconomic effect has become better understood. Firm growth has a significant influence on national economic health, especially small economies such as Finland, yet scholars agree that little is known about the phenomena. Authors of this study aim deliver a broader and more holistic approach to firm growth research and integrate currently fragmented constructs. By studying participants of Kasv...

  7. Does Design Activity Stimulate Firm Productivity? (Japanese)

    OpenAIRE

    KAWAKAMI Atsushi; EDAMURA Kazuma

    2015-01-01

    This paper investigates the influence of firms' design activity to total factor productivity using firm-level data from the Basic Survey of Japanese Business Structure and Activities and the Survey on Research Activities of Private Corporations. We adopt two approaches for calculating design activity. First, we regard registered design as a design activity. Second, we calculate design investment from the Survey on Research Activities of Private Corporations and estimate the relation between d...

  8. Segmentation, Reconstruction, and Analysis of Blood Thrombus Formation in 3D 2-Photon Microscopy Images

    Directory of Open Access Journals (Sweden)

    Xu Zhiliang

    2010-01-01

    Full Text Available We study the problem of segmenting, reconstructing, and analyzing the structure growth of thrombi (clots in blood vessels in vivo based on 2-photon microscopic image data. First, we develop an algorithm for segmenting clots in 3D microscopic images based on density-based clustering and methods for dealing with imaging artifacts. Next, we apply the union-of-balls (or alpha-shape algorithm to reconstruct the boundary of clots in 3D. Finally, we perform experimental studies and analysis on the reconstructed clots and obtain quantitative data of thrombus growth and structures. We conduct experiments on laser-induced injuries in vessels of two types of mice (the wild type and the type with low levels of coagulation factor VII and analyze and compare the developing clot structures based on their reconstructed clots from image data. The results we obtain are of biomedical significance. Our quantitative analysis of the clot composition leads to better understanding of the thrombus development, and is valuable to the modeling and verification of computational simulation of thrombogenesis.

  9. The Variance Composition of Firm Growth Rates

    Directory of Open Access Journals (Sweden)

    Luiz Artur Ledur Brito

    2009-04-01

    Full Text Available Firms exhibit a wide variability in growth rates. This can be seen as another manifestation of the fact that firms are different from one another in several respects. This study investigated this variability using the variance components technique previously used to decompose the variance of financial performance. The main source of variation in growth rates, responsible for more than 40% of total variance, corresponds to individual, idiosyncratic firm aspects and not to industry, country, or macroeconomic conditions prevailing in specific years. Firm growth, similar to financial performance, is mostly unique to specific firms and not an industry or country related phenomenon. This finding also justifies using growth as an alternative outcome of superior firm resources and as a complementary dimension of competitive advantage. This also links this research with the resource-based view of strategy. Country was the second source of variation with around 10% of total variance. The analysis was done using the Compustat Global database with 80,320 observations, comprising 13,221 companies in 47 countries, covering the years of 1994 to 2002. It also compared the variance structure of growth to the variance structure of financial performance in the same sample.

  10. Early activation of inflammation and clotting in the preterm lamb with neonatal RDS : Comparison of conventional ventilation and high frequency oscillatory ventilation

    NARCIS (Netherlands)

    Jaarsma, AS; Geven, WB; Van Oeveren, W; Oetomo, SB

    2001-01-01

    In neonatal respiratory distress syndrome activation of inflammation and clotting is demonstrated. High frequency oscillatory ventilation (HFOV) is considered to be less damaging to the human preterm lung, resulting in less activation of inflammation and clotting compared with conventional

  11. Plasma fibrin clot properties in the G20210A prothrombin mutation carriers following venous thromboembolism: the effect of rivaroxaban.

    Science.gov (United States)

    Janion-Sadowska, Agnieszka; Natorska, Joanna; Siudut, Jakub; Ząbczyk, Michal; Stanisz, Andrzej; Undas, Anetta

    2017-08-30

    We sought to investigate whether the G20210A prothrombin mutation modifies plasma fibrin clot properties in patients after venous thromboembolism (VTE) and how rivaroxaban treatment affects these alterations. We studied 34 prothrombin mutation heterozygous carriers and sex- and age-matched 34 non-carriers, all at least three months since the first VTE episode, before and during treatment with rivaroxaban. Clot permeability (K s ) and clot lysis time (CLT) with or without elimination of thrombin activatable fibrinolysis inhibitor (TAFI) were assessed at baseline, 2-6 hours (h) after and 20-25 h after intake of rivaroxaban (20 mg/day). At baseline, the prothrombin mutation group formed denser clots (K s -12 %, p=0.0006) and had impaired fibrinolysis (CLT +14 %, p=0.004, and CLT-TAFI +13 %, p=0.03) compared with the no mutation group and were similar to those observed in 15 healthy unrelated prothrombin mutation carriers. The G20210A prothrombin mutation was the independent predictor for K s and CLT before rivaroxaban intake. At 2-6 h after rivaroxaban intake, clot properties improved in both G20210A carriers and non-carriers (K s +38 %, and +37 %, CLT -25 % and -25 %, CLT-TAFI -20 % and -24 %, respectively, all pCLT +17 %, CLT-TAFI +13 %, all p<0.001). Rivaroxaban concentration correlated with fibrin clot properties. After 20-25 h since rivaroxaban intake most clot properties returned to baseline. Rivaroxaban-related differences in clot structure were confirmed by scanning electron microscopy images. In conclusion, rivaroxaban treatment, though improves fibrin clot properties, cannot abolish more prothrombotic fibrin clot phenotype observed in prothrombin mutation carriers following VTE.

  12. Firm Heterogeneity and Different Modes of Internationalization: Evidence from Japanese Firms

    OpenAIRE

    Ryuhei Wakasugi; Ayumu Tanaka

    2009-01-01

    This paper examines how differently productivity heterogeneity of firms sorts their export and foreign direct investment (FDI) between North and South as well as between single and multiple destinations. The empirical examinations based on 12,000 Japanese firm-level data present new findings; the rank of productivity differently sorts the internationalization modes between North (North America and Europe) and South (East Asia); the productivity of firms internationalizing in both North Americ...

  13. Staphylococcus chromogenes, a Coagulase-Negative Staphylococcus Species That Can Clot Plasma

    Science.gov (United States)

    dos Santos, Danielle Cabral; Lange, Carla Christine; Avellar-Costa, Pedro; dos Santos, Katia Regina Netto; Brito, Maria Aparecida Vasconcelos Paiva

    2016-01-01

    Staphylococcus chromogenes is one of the main coagulase-negative staphylococci isolated from mastitis of dairy cows. We describe S. chromogenes isolates that can clot plasma. Since the main pathogen causing mastitis is coagulase-positive Staphylococcus aureus, the coagulase-positive phenotype of S. chromogenes described here can easily lead to misidentification. PMID:26912749

  14. Staphylococcus chromogenes, a Coagulase-Negative Staphylococcus Species That Can Clot Plasma.

    Science.gov (United States)

    Dos Santos, Danielle Cabral; Lange, Carla Christine; Avellar-Costa, Pedro; Dos Santos, Katia Regina Netto; Brito, Maria Aparecida Vasconcelos Paiva; Giambiagi-deMarval, Marcia

    2016-05-01

    Staphylococcus chromogenes is one of the main coagulase-negative staphylococci isolated from mastitis of dairy cows. We describe S. chromogenes isolates that can clot plasma. Since the main pathogen causing mastitis is coagulase-positive Staphylococcus aureus, the coagulase-positive phenotype of S. chromogenes described here can easily lead to misidentification. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  15. Staphylococcus chromogenes, a Coagulase-Negative Staphylococcus Species That Can Clot Plasma

    OpenAIRE

    dos Santos, Danielle Cabral; Lange, Carla Christine; Avellar-Costa, Pedro; dos Santos, Katia Regina Netto; Brito, Maria Aparecida Vasconcelos Paiva; Giambiagi-deMarval, Marcia

    2016-01-01

    Staphylococcus chromogenes is one of the main coagulase-negative staphylococci isolated from mastitis of dairy cows. We describe S. chromogenes isolates that can clot plasma. Since the main pathogen causing mastitis is coagulase-positive Staphylococcus aureus, the coagulase-positive phenotype of S. chromogenes described here can easily lead to misidentification.

  16. 7 CFR 58.436 - Rennet, pepsin, other milk clotting enzymes and flavor enzymes.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Rennet, pepsin, other milk clotting enzymes and flavor...) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946 AND THE EGG PRODUCTS...

  17. Clotting of cow (Bos taurus) and goat milk ( Capra hircus ) using ...

    African Journals Online (AJOL)

    The ease to locally produce kid rennet contrary to that of calve has led us to compare the proteolytic and clotting activities of these two rennets depending on their action on goat (Capra hircus) milk and cow (Bos taurus) milk. The proteolysis was measured by determining the increase of non-protein nitrogen according to the ...

  18. Production of milk-clotting enzyme by Bacillus subtilis B1 from wheat ...

    African Journals Online (AJOL)

    Three strains, Bacillus subtilis B1, B. subtilis B18 and Bacillus thuringiensis B12, were screened from wheat bran to produce milk-clotting enzyme. Among them, B. subtilis B1 exhibited considerable milkclotting activity with low proteolytic activity. After response surface methodology optimization, milkclotting activity was ...

  19. Transgenic mice can express mutant human coagulation factor IX with higher level of clotting activity.

    Science.gov (United States)

    Yan, Jing-Bin; Wang, Shu; Huang, Wen-Ying; Xiao, Yan-Ping; Ren, Zhao-Rui; Huang, Shu-Zheng; Zeng, Yi-Tao

    2006-10-01

    To improve the available values of transgenic animals, we produced a mutant human coagulation factor IX minigene (including cDNA and intron I) with arginine at 338 changed to alanine (R338A-hFIX) by using a direct mutation technique. The R338A-hFIX minigene was then cloned into a plasmid carrying the goat beta-casein promoter to get a mammary gland-specific expression vector. The clotting activity in the supernatant of the transfected HC-11 cells increased to approximately three times more than that of wild-type hFIX. Nine transgenic mice (three females and six males) were produced, and the copy number of the foreign gene was very different, ranging from 1 to 43 in different lines. ELISA, Western blot, and clotting assay experiments showed that the transgenic mice could express R338A-hFIX, showing higher average levels of clotting activity than wild-type hFIX in the milk (103.76% vs. 49.95%). The highest concentration and clotting activity of hFIX reached 26 mug/mL and 1287% in one founder (F(0)-7), which was over 10 times higher than that in human plasma. Furthermore, RT-PCR, APTT assay, and histological analysis indicated that hFIX was expressed specifically in the mammary gland without affecting the intrinsic coagulation pathway and physiologic performance of the local tissue.

  20. Ultrasonographic imaging of abomasal milk clotting and abomasal diameter in healthy and diarrheic calves.

    Science.gov (United States)

    Kirchner, Daniela; Schwedhelm, Lea; Wenge, Julia; Steinhöfel, Ilka; Heinrich, Christian; Coenen, Manfred; Bachmann, Lisa

    2015-11-01

    In case of diarrhea calves are treated with oral rehydration solutions (ORS), which are known to increase abomasal pH and inhibit milk clotting in vitro. Nevertheless, recent studies have shown that ORS with HCO3(-) ≤ 62 mmol/L do not interfere with abomasal milk clotting in healthy calves. However, in diarrheic calves, feeding ORS and milk simultaneously may disturb abomasal curd formation and exacerbate diarrhea due to faster abomasal passage of ingesta. Therefore, the aim of the present study was to ultrasonographically examine abomasal milk clotting and diameter after feeding milk and milk replacer (MR) with and without ORS to healthy and diarrheic calves. Abomasal curd formation and diameter in healthy and diarrheic calves were ultrasonographically imaged before and after feeding milk, MR and ORS prepared in milk or MR. Feeding mixtures of milk or MR with ORS did not cause any remarkable differences in the ultrasonographic images of abomasal content. Moreover, abomasal milk clotting was not disturbed due to diarrhea. Statistically significant differences of abomasal diameter after feeding between healthy and diarrheic calves indicated that abomasal emptying is delayed in diarrheic calves. Hence, further studies are needed to determine reasons for decelerated abomasal passage in calves suffering from diarrhea. © 2015 Japanese Society of Animal Science.