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Sample records for aplasia irreversible por

  1. Vermian aplasia and hypoplasia

    International Nuclear Information System (INIS)

    This paper reports vermian aplasia or hypoplasia unrelated to Dandy-Walker complex or Joubert syndrome. Vermian hypoplasia is most commonly associated with the malformations of Dandy-Walker cyst or variant. There have been few reports of familial vermian anomaly (Joubert syndrome) with episodes of polypnea and apnea. Five patients with vermian hypoplasia or absence were prospectively discovered among 1,130 children undergoing brain MR imaging. Ages ranged from 2 mo to 15 y at the time of discovery: The abnormalities were poorly defined in three patients who had previously undergone CT. There was no common link in these patients with a variable number of other systemic, brain, or facial abnormalities. No unifying symptoms were identified. Two patients had the MR imaging appearance of Joubert syndrome, but none had the cyclical respiratory symptoms usually associated with this syndrome

  2. Radiological Findings of Michel Aplasia

    Science.gov (United States)

    Umul, Ayse; Demirtas, Hakan; Celik, Ahmet Orhan

    2016-01-01

    Introduction: Congenital abnormalities of the inner ear is the most common cause of neurosensory hearing loss. Michel inner ear deformity is a rare developmental anomaly refers to the total aplasia of the inner ear. It is caused by developmental arrest of otic placode early during the third week of gestational age. Case report: We have discussed here that three year old girl diagnosed Michel aplasia with temporal bone computed tomography (CT) and temporal magnetic resonance imaging (MRI) findings. PMID:27482139

  3. Pure red cell aplasia and associated thymoma

    Directory of Open Access Journals (Sweden)

    Cristian Rosu

    2011-04-01

    Full Text Available Pure red cell aplasia is a rare cause of anemia, caused by an absence of red blood cell precursors in the bone marrow. It is usually a paraneoplastic syndrome, associated most commonly with large-cell granular lymphocyte leukemia but also thymoma. For patients who present both pure red cell aplasia and thymoma, thymectomy leads to an initial remission of the aplasia in 30% of cases. However, sustained remission may require the addition of medications such as corticosteroids, cyclospo­rine, or cyclophosphamide. We present a case of pure red cell aplasia associated with a thymoma in an otherwise healthy 80 year-old woman.

  4. Aplasia pura de serie roja post-trasplante alogeneico de células progenitoras hematopoyeticas ABO incompatible Pure red cell aplasia after ABO incompatible bone marrow transplantation

    OpenAIRE

    E. Bulliorsky; C. Shanley; G. Stemmelin; J. Ceresetto; O. Rabinovich

    2002-01-01

    El trasplante alogeneico de células progenitoras hematopoyéticas (TCPH) con incompatibilidad ABO entre el donante y el receptor puede en ocasiones asociarse a trastornos en la progenie eritroide desarrollada a partir de la médula ósea trasplantada, caracterizado por un funcionamiento tardío, inadecuado e incompleto de la misma. En este contexto, la aplasia pura de serie roja es la complicación más severa. Se han intentado tratamientos para la aplasia pura de serie roja post-TCPH con eritropoy...

  5. Genetics Home Reference: nonsyndromic aplasia cutis congenita

    Science.gov (United States)

    ... round or oval, others rectangular, and still others star-shaped. They usually leave a scar after they ... pregnant mother can cause the baby to be born with the skin lesions characteristic of nonsyndromic aplasia ...

  6. Aplasia of major pectoral muscle combined with renal aplasia and cystic malformation of common iliac vein

    DEFF Research Database (Denmark)

    Qvist, N; Nielsen, K; Christensen, P V

    1987-01-01

    We report a case of an eighteen-year-old male with combined aplasia of the major pectoral muscle, renal aplasia, and malformation of the common iliac vein. The possibility of a common genesis is discussed on the basis of embryology....

  7. Rol de la CaMKII en la injuria irreversible por isquemia y reperfusión

    OpenAIRE

    Di Carlo, Mariano Nahuel

    2016-01-01

    La palabra isquemia hace referencia a un riego sanguíneo insuficiente de los tejidos provocado por obstrucción del flujo arterial. La aterosclerosis coronaria es el substrato patológico subyacente en la mayoría de los casos de isquemia miocárdica [Gimbrone MA, 2013]. La reducción o el cese del suministro de sangre al corazón, conduce a la depleción de oxígeno y sustratos metabólicos alterando la homeostasis celular. Si el tiempo de isquemia se prolonga y en ausencia de circulación colateral s...

  8. Microscopic irreversibility

    OpenAIRE

    Karl Gustafson

    2004-01-01

    First, I will recount the substance of several important conversations I had with Ilya Prigogine over the years. There is no doubt in my mind that Professor Prigogine firmly believed in the underlying stochasticity of the universe. Second, I will summarize my curiosity about the principle of detailed balance. In my opinion, so far it has always been put in by hand. Third, I will advance my own theory of microscopic irreversibility, that is, irreversibility at the quantum ...

  9. Ectrodactyly with fibular aplasia : A separate entity?

    NARCIS (Netherlands)

    Menke, Leonie A.; Bijlsma, Emilia K.; van Essen, Anthonie J.; van den Boogaard, Marie-Jose H.; van Rijn, Rick R.; Cobben, Jan Maarten

    2008-01-01

    E/FA is the combination of ectrodactyly (split hand/foot malformation, SHFM) and fibular aplasia. It is a rare disorder considered to be inherited in an autosomal dominant fashion with reduced penetrance and variable expression. In order to determine recurrence risks for the two patients we describe

  10. Aplasia pura de serie roja post-trasplante alogeneico de células progenitoras hematopoyeticas ABO incompatible Pure red cell aplasia after ABO incompatible bone marrow transplantation

    Directory of Open Access Journals (Sweden)

    E. Bulliorsky

    2002-12-01

    Full Text Available El trasplante alogeneico de células progenitoras hematopoyéticas (TCPH con incompatibilidad ABO entre el donante y el receptor puede en ocasiones asociarse a trastornos en la progenie eritroide desarrollada a partir de la médula ósea trasplantada, caracterizado por un funcionamiento tardío, inadecuado e incompleto de la misma. En este contexto, la aplasia pura de serie roja es la complicación más severa. Se han intentado tratamientos para la aplasia pura de serie roja post-TCPH con eritropoyetina o plasmaféresis, con relativo éxito. Algunos autores han informado también la utilización de globulina antilinfocitaria, asumiendo que dicha aplasia selectiva de la serie roja en la médula ósea trasplantada es mediada por un mecanismo inmune. En este trabajo se describe un paciente portador de una leucemia aguda en quien se realizó un TCPH alogeneico (ABO incompatible con su donante. Teniendo niveles bajos de aglutininas contra el grupo sanguíneo de la donante, desarrolló una aplasia pura de serie roja post - TCPH. La misma no mejoró con tratamiento con eritropoyetina o con un refuerzo de progenitores hematopoyéticos de sangre periférica de la misma donante (boost, resolviéndose totalmente luego de un tratamiento exitoso con globulina antilinfocitaria de origen equino.ABO incompatibility in allogeneic bone marrow transplantation may be associated with incomplete or delayed erythroid engraftment, being pure red cell aplasia (PRCA the most severe complication in this setting. Attempts for the treatment of PRCA have been made with erythropoietin or with plasmapheresis with relative success, and some authors have reported the reversibility of PRCA with antilymphocyte globulin (ALG or ATG, based on the assumption that PRCA might be immunologically mediated. We report herewith a patient with acute leukemia who developed post - BMT pure red cell aplasia. His sibling donor (sister was HLA identical and ABO incompatible, having low agglutinin

  11. Microscopic irreversibility

    Directory of Open Access Journals (Sweden)

    Karl Gustafson

    2004-05-01

    Full Text Available First, I will recount the substance of several important conversations I had with Ilya Prigogine over the years. There is no doubt in my mind that Professor Prigogine firmly believed in the underlying stochasticity of the universe. Second, I will summarize my curiosity about the principle of detailed balance. In my opinion, so far it has always been put in by hand. Third, I will advance my own theory of microscopic irreversibility, that is, irreversibility at the quantum level. This involves new concepts of probability preference and probability violation. A manifestation of this irreversibility may be seen during emission of bound-free photons during field-matter interactions. Entropy increase is tied to radiation increase, and the notion of heat bath becomes light bath.

  12. Aplasia Cutis Congenita: a Case Report

    Directory of Open Access Journals (Sweden)

    Tahereh Esmaeilnia Shirvany

    2009-06-01

    Full Text Available Background:Aplasia cutis congenital (ACC is a congenital absence of skin most commonly affecting the scalp. No definite etiology is available but multiple causes such as intrauterine infection, fetal exposure to cocaine, heroin, alcohol or antithyroid drugs, vascular disruption, genetic causes, syndromes and teratogens have been suggested. Case Presentation: We present an infant with symmetrical type of aplasia cutis on the trunk and proximal limbs. She was product of triple pregnancy with two fetuses papyraceous at 12th week of gestational age and at birth. She is treated by non surgical management despite remarkable extent of the lesion.Conclusion:ACC of the trunk is less common than of scalp. Lesion often is symmetric and seen after fetus papyraceous in multiple pregnancies.

  13. Aplasia pura de serie roja post-trasplante alogeneico de células progenitoras hematopoyeticas ABO incompatible

    OpenAIRE

    E. Bulliorsky; C. Shanley; G. Stemmelin; J. Ceresetto; O. Rabinovich

    2002-01-01

    El trasplante alogeneico de células progenitoras hematopoyéticas (TCPH) con incompatibilidad ABO entre el donante y el receptor puede en ocasiones asociarse a trastornos en la progenie eritroide desarrollada a partir de la médula ósea trasplantada, caracterizado por un funcionamiento tardío, inadecuado e incompleto de la misma. En este contexto, la aplasia pura de serie roja es la complicación más severa. Se han intentado tratamientos para la aplasia pura de serie roja post-TCPH con eritropoy...

  14. Pure white cell aplasia in a dog.

    Science.gov (United States)

    Weiss, Douglas J; Henson, Michael

    2007-12-01

    A 3-year-old Irish Wolfhound was evaluated because of acute onset of lethargy and fever. Severe neutropenia (0/microL; reference interval 2500-11,200/microL) was associated with granulocyte aplasia in the bone marrow (myeloid:erythroid ratio, 0.009:1). Antineutrophil antibodies were assessed by an indirect immunofluorescence assay using flow cytometry. When normal canine leukocytes were incubated with the patient's serum and anti-IgG, a marked shift was observed in the forward-angle light scatter of the neutrophil population, and the monocyte cluster disappeared, possibly the result of fragmentation or lysis. Both neutrophil fluorescence intensity (309 +/- 11 median channel units [MCU], control values 107-152 MCU) and the percentage of neutrophils with increased fluorescence intensity (61 +/- 5%, control values 3.8-13.7%) were increased in the patient's serum, consistent with the presence of antineutrophil antibodies. Repeated episodes of neutropenia occurred while treatment with steroidal and nonsteroidal immunosuppressive therapy was initiated and modified. The neutrophil count eventually stabilized in the low-normal range, and the dog was maintained for the next 15 months on prednisone (0.4 mg/kg PO q 48 h) and azathioprine (2 mg/kg daily). During this period, the dog developed immune-mediated hemolytic anemia and thrombocytopenia, decubital ulcers, nasal aspergillosis, and eventually, multi-organ septicemia, which led to euthanasia on day 784. A diagnosis of pure white cell aplasia was made in this dog, based on the many similarities to human patients with pure white cell aplasia, including severe neutropenia with selective granulocyte aplasia, serum antineutrophil antibodies, remission dependent on treatment with immunosuppressive therapy, and recurrent bacterial infections. PMID:18041706

  15. Irreversible Electroporation.

    Science.gov (United States)

    Narayanan, Govindarajan

    2015-12-01

    Irreversible electroporation (IRE) is a predominantly nonthermal ablative technology that uses high-voltage, low-energy DC current pulses to induce cell death. Thermal ablative technologies such as radiofrequency ablation, microwave ablation, and cryoablation have several applications in oncology but have limitations that have been established. IRE has shown promise to overcome some of these limitations. This article reviews the basics of the technology, patient selection, clinical applications, practical pointers, and the published data. PMID:26622097

  16. Aplasia pura de serie roja post-trasplante alogeneico de células progenitoras hematopoyeticas ABO incompatible

    Directory of Open Access Journals (Sweden)

    E. Bulliorsky

    2002-12-01

    Full Text Available El trasplante alogeneico de células progenitoras hematopoyéticas (TCPH con incompatibilidad ABO entre el donante y el receptor puede en ocasiones asociarse a trastornos en la progenie eritroide desarrollada a partir de la médula ósea trasplantada, caracterizado por un funcionamiento tardío, inadecuado e incompleto de la misma. En este contexto, la aplasia pura de serie roja es la complicación más severa. Se han intentado tratamientos para la aplasia pura de serie roja post-TCPH con eritropoyetina o plasmaféresis, con relativo éxito. Algunos autores han informado también la utilización de globulina antilinfocitaria, asumiendo que dicha aplasia selectiva de la serie roja en la médula ósea trasplantada es mediada por un mecanismo inmune. En este trabajo se describe un paciente portador de una leucemia aguda en quien se realizó un TCPH alogeneico (ABO incompatible con su donante. Teniendo niveles bajos de aglutininas contra el grupo sanguíneo de la donante, desarrolló una aplasia pura de serie roja post - TCPH. La misma no mejoró con tratamiento con eritropoyetina o con un refuerzo de progenitores hematopoyéticos de sangre periférica de la misma donante (boost, resolviéndose totalmente luego de un tratamiento exitoso con globulina antilinfocitaria de origen equino.

  17. Irreversible cycle in linear irreversible thermodynamics

    International Nuclear Information System (INIS)

    The reversible Carnot cycle in reversible thermodynamics is composed of two reversible heat exchange processes and two reversible adiabatic processes. We construct an irreversible cycle in linear irreversible thermodynamics by analogy with the reversible Carnot cycle. The irreversible cycle is composed of two linear irreversible heat exchange processes and two linear irreversible adiabatic processes. It is found that the Curzon-Alhborn efficiency can be attained if the power for each of the four linear irreversible processes reaches its maximum. The maximum efficiency is the Carnot efficiency. The strong coupling condition is prerequisite for the respective attainment of the Curzon-Alhborn efficiency and the Carnot efficiency.

  18. Pulmonary Aplasia in an Adult : A Case Report

    Directory of Open Access Journals (Sweden)

    Nurettin Yiyit

    2016-01-01

    Full Text Available Pulmonary aplasia is a rare congenital anomaly in which there are absence of pulmonary vessels, bronchus and parenchyma. It is distinguished from pulmonary agenesis by the presence of rudimentary stump bronchus. Patients are usually diagnosed in childhood. Patients without additional anomaly and the patients with mild disease can be diagnosed in adulthood. The left lung was not observed at the chest X-ray of 19-year-old male patient with respiratory distress in exercise. Left lung aplasia was diagnosed by computed tomography and ventilation perfusion scintigraphy. The patients with lung aplasia have an increased risk of infections. Therefore the follow-up of the patients is important.

  19. Genetics Home Reference: Müllerian aplasia and hyperandrogenism

    Science.gov (United States)

    Skip to main content Your Guide to Understanding Genetic Conditions Enable Javascript for addthis links to activate. ... Conditions Genes Chromosomes & mtDNA Resources Help Me Understand Genetics Home Health Conditions Müllerian aplasia and hyperandrogenism Müllerian ...

  20. Laparoscopic Morcellation of Didelphic Uterus With Cervical and Renal Aplasia

    OpenAIRE

    Altchek, Albert; Brodman, Michael; Schlosshauer, Peter; Deligdisch, Liane

    2009-01-01

    This is a case report (and review of the literature) of a 12-year and 10-month-old girl with a rare congenital anomaly of uterus didelphys, unilateral cervix aplasia, and ipsilateral renal aplasia. She had severe dysmenorrhea from the first menses. In an effort to preserve fertility, a cervical fistula was made that closed over. A laparoscopic hemi-hysterectomy was done successfully and rapidly with laparoscopic morcellation. Because no ureter was present, it was not necessary to trace it. Fo...

  1. CT complete congenital eventration of diaphragm with aplasia of lung

    International Nuclear Information System (INIS)

    Diaphragmatic anomalies are commonly associated with unilateral pulmonary hypoplasias. However complete eventration of the diaphragm with aplasia of the ipsilateral lung is a rare combination of congenital anomalies. The clinical profile and computed tomography (CT) findings in a new-born with complete eventration of right hemidiaphragm and aplasia of right lung are presented. It is thus demonstrated that CT is a very effective, non invasive means of diagnosis which in the past depended largely on invasive procedures such as bronchography, angiography and thoracotomy. 16 refs., 3 figs

  2. Aplasia cutis congenita of the scalp: Therapeutic modalities

    OpenAIRE

    Shivakumar S; Dwarakanath S; Swaroop Gopal; Venkataramana N

    2006-01-01

    Agenesis of scalp is an uncommon but well-recognized clinical entity. Congenital scalp and skull defects can be either obvious or occult; over 300 cases have been reported in literature. Aplasia cutis congenita (ACC) is recognized as a heterogeneous disorder, all characterized by focal absence of the epidermis, dermis and sometimes the calvarium and/or dura. We present a case of ACC in an infant whose mother was exposed to a teratogenic drug (Methimazole - an antithyroid drug) during pregnanc...

  3. The role of diclofenack on inducing of aplasia cutis congenita: a case report

    OpenAIRE

    Pajaziti, Laura; Rexhepi, Syzana; Shatri-Muça, Ylfete; Ferizi, Mybera

    2009-01-01

    Background Aplasia cutis congenita is a disorder where e newborn child is missing skin from certain areas. It is a rare condition with no particular race or sex more at risk. May occur by itself or be associated with other physical syndromes or disorders. A classification system exists for aplasia cutis congenital consisting of 9 groups, based on the number and location of the skin defects and the presence or absence of other malformations. Causes of aplasia congenital could be heredity, tera...

  4. Irreversible processes kinetic theory

    CERN Document Server

    Brush, Stephen G

    2013-01-01

    Kinetic Theory, Volume 2: Irreversible Processes deals with the kinetic theory of gases and the irreversible processes they undergo. It includes the two papers by James Clerk Maxwell and Ludwig Boltzmann in which the basic equations for transport processes in gases are formulated, together with the first derivation of Boltzmann's ""H-theorem"" and a discussion of this theorem, along with the problem of irreversibility.Comprised of 10 chapters, this volume begins with an introduction to the fundamental nature of heat and of gases, along with Boltzmann's work on the kinetic theory of gases and s

  5. Irreversibility and quantum mechanics

    International Nuclear Information System (INIS)

    Quantum mechanisms has a dual structure: while Schroedinger equation corresponds to a deterministic and time-reversible description, measurement introduces irreversibility and stochasticity. This contrasts with the Bohr-Sommerfeld-Einsten theory, in which transitions between quantum states are associated with spontaneous and induced transitions, defined in terms of a stochastic process. A new form of quantum theory is summarized here, which contains an intrinsic form of irreversibility, independent of observation

  6. Irreversibility, Uncertainty, and Investment

    OpenAIRE

    Robert S. Pindyck

    1990-01-01

    Most investment expenditures have two important characteristics: First, they are largely irreversible; the firm cannot disinvest, so the expenditures are sunk costs. Second, they can be delayed, allowing the firm to wait for new information about prices, costs, and other market conditions before committing resources. An emerging literature has shown that this has important implications for investment decisions, and for the determinants of investment spending. Irreversible investment is especi...

  7. THE PURE RED BLOOD CELL APLASIA IN RENAL TRANSPLANT RECIPIENT

    Directory of Open Access Journals (Sweden)

    B. T. Dzumabaeva

    2011-01-01

    Full Text Available The pure red blood cell aplasia of renal transplant recipients caused by parvovirus B19 (PB19 is characterized by persistent anemia which resistant to erythropoietin therapy, lack of reticulocytes, bone marrow hypoplasia, and clinically accompanied by severe recurrent bacterial, fungal and viral infection. In case of reactivation PB19 it is necessarv, first of all, eliminate the causes activation of this virus and to cancel or reduce the dose of drugs which depressed the normal hematopoiesis germs, thus to reduce the pancytopenia associating complications in this population. 

  8. Pure red cell aplasia induced by epoetin zeta.

    Science.gov (United States)

    Panichi, Vincenzo; Ricchiuti, Guido; Scatena, Alessia; Del Vecchio, Lucia; Locatelli, Francesco

    2016-08-01

    Pure red cell aplasia (PRCA) may develop in patients with chronic kidney disease receiving erythropoiesis-stimulating agents (ESA). We report on a 72-year-old patient who developed hypo-proliferative anaemia unresponsive to ESA following the administration of epoetin zeta subcutaneously for 7 months. On the basis of severe isolated hypoplasia of the erythroid line in the bone marrow and high-titre neutralizing anti-erythropoietin antibodies (Ab), a diagnosis of Ab-mediated PRCA was made. Epoetin zeta was discontinued and the patient was given steroids. This was associated with anaemia recovery. To our knowledge this is the first PRCA case related to epoetin zeta. PMID:27478604

  9. Aplasia cutis congenita of the scalp: Therapeutic modalities

    Directory of Open Access Journals (Sweden)

    Shivakumar S

    2006-01-01

    Full Text Available Agenesis of scalp is an uncommon but well-recognized clinical entity. Congenital scalp and skull defects can be either obvious or occult; over 300 cases have been reported in literature. Aplasia cutis congenita (ACC is recognized as a heterogeneous disorder, all characterized by focal absence of the epidermis, dermis and sometimes the calvarium and/or dura. We present a case of ACC in an infant whose mother was exposed to a teratogenic drug (Methimazole - an antithyroid drug during pregnancy. This case report is presented to highlight the steps to successful management. Definitive full thickness scalp cover at the earliest avoids secondary infection, eschar formation and exsanguination.

  10. Stochastic dynamics and irreversibility

    CERN Document Server

    Tomé, Tânia

    2015-01-01

    This textbook presents an exposition of stochastic dynamics and irreversibility. It comprises the principles of probability theory and the stochastic dynamics in continuous spaces, described by Langevin and Fokker-Planck equations, and in discrete spaces, described by Markov chains and master equations. Special concern is given to the study of irreversibility, both in systems that evolve to equilibrium and in nonequilibrium stationary states. Attention is also given to the study of models displaying phase transitions and critical phenomema both in thermodynamic equilibrium and out of equilibrium. These models include the linear Glauber model, the Glauber-Ising model, lattice models with absorbing states such as the contact process and those used in population dynamic and spreading of epidemic, probabilistic cellular automata, reaction-diffusion processes, random sequential adsorption and dynamic percolation. A stochastic approach to chemical reaction is also presented.The textbook is intended for students of ...

  11. Pure red cell aplasia following autoimmune hemolytic anemia: An enigma

    Directory of Open Access Journals (Sweden)

    M Saha

    2013-01-01

    Full Text Available A 26-year-old previously healthy female presented with a 6-month history of anemia. The laboratory findings revealed hemolytic anemia and direct antiglobulin test was positive. With a diagnosis of autoimmune hemolytic anemia (AIHA, prednisolone was started but was ineffective after 1 month of therapy. A bone marrow trephine biopsy revealed pure red cell aplasia (PRCA showing severe erythroid hypoplasia. The case was considered PRCA following AIHA. This combination without clear underlying disease is rare. Human parvovirus B19 infection was not detected in the marrow aspirate during reticulocytopenia. The patient received azathioprine, and PRCA improved but significant hemolysis was once again documented with a high reticulocyte count. The short time interval between AIHA and PRCA phase suggested an increased possibility of the evolution of a single disease.

  12. APLASIA CUTIS CONGENITA SCALP PRESENTING WITH LIFE THREATENING HEMORRHAGE: A CASE REPORT

    Directory of Open Access Journals (Sweden)

    Farrukh Mahmood

    2012-01-01

    Full Text Available Aplasia cutis congenita is a rare congenital anomaly characterized by the absence of a patch of skin since birth. It may lead to life threatening complications at times. A 5-day-old neonate with Aplasia cutis congenita was received in a state of shock due to tremendous blood loss from the superior sagittal sinus. The neonate was resuscitated immediately followed by closure of the superior sagittal sinus and flap coverage to the defect as a life saving procedure.

  13. Pure red cell aplasia in a simultaneous pancreas-kidney transplantation patient: inside the erythroblast

    Directory of Open Access Journals (Sweden)

    Francesca Labbadia

    2012-09-01

    Full Text Available A case of pure red cell aplasia in a simultaneous kidney-pancreas transplant recipient on immunosuppressive therapy is reported here. The patient presented with anemia unresponsive to erythropoietin treatment. Bone marrow cytomorphology was highly suggestive of parvovirus pure red cell aplasia, which was confirmed with serology and polymerase chain reaction positive for parvovirus B19 DNA in peripheral blood. After the administration of intravenous immunoglobulin the anemia improved with a rising number of the reticulocytes.

  14. Uterine horn aplasia with complications in two mixed-breed bitches : case report

    OpenAIRE

    M.L. Schulman; L.A. Bolton

    1997-01-01

    Unilateral segmental uterine horn aplasia was found in 2 mixed-breed bitches. The 1st bitch was presented with clinical signs of acute abdominal pain, and pyometra was suspected. Pyometra was confirmed surgically with rupture of a blind-ending cranial portion of the anomalous right uterine horn, which had resulted in peritonitis. The 2nd bitch was presented for routine ovariohysterectomy. The right uterine horn was affected by segmental aplasia, with mucometra of the cranial portion of the af...

  15. Marrow fat cell: response to x-ray induced aplasia

    International Nuclear Information System (INIS)

    Adipose tissue is an integral structural component of normal rabbit marrow and is believed to behave primarily as a cushion in response to hemopoietic proliferation, accommodating to changes in hemopoiesis by change in either size or number or both of the fat cells in order to maintain constancy of the marrow volume. To test this hypothesis, aplasia of the right femur of New Zealand white rabbits was induced by x irradiation with 8000 rads; the left unirradiated limb served as control. Twenty-four hours before sacrifice 50 μCi of palmitate-114C was administered intravenously and the marrow of both femurs removed. Samples of perinephric fat were taken for comparison. Fat cell volume, C14 palmitate turnover and fatty acid composition were determined. The total number of fat cells in the entire marrow of both femurs was calculated. The measurements showed no difference in size or fatty acid turnover of the fat cells in the irradiated aplastic marrow from the cells of the control marrow. The number of fat cells in both the irradiated and the unirradiated control femurs was essentially the same. These findings do not support the view that marrow fat cells respond to diminished hematopoiesis by either increase in their volume or number. In addition, the findings suggest that both marrow and subcutaneous fat cells are fairly resistant to high doses of x-ray irradiation

  16. Aplasia transitória da série vermelha na anemia falciforme Transient red cell aplasia in sickle cell disease

    Directory of Open Access Journals (Sweden)

    Mônica P. A. Veríssimo

    2007-09-01

    Full Text Available A doença falciforme, devido à vida média encurtada das hemácias, pelo quadro de hemólise crônica, pode apresentar um quadro clínico grave de anemia quando ocorre supressão da eritropoese devida à infecção pelo Parvovírus humano B19. O quadro clínico apresenta-se com febre, que pode preceder a anemia grave, fraqueza e mal- estar, além de sinais laboratoriais como queda da hemoglobina e reticulocitopenia importante. Diagnóstico laboratorial pode ser por imunofluorescência ou ensaio enzimático. O tratamento é a transfusão de concentrado de hemácias. Pode haver complicações associadas a esta infecção, tais como seqüestro esplênico, seqüestro hepático, síndrome torácica aguda, síndrome nefrótica, meningoencefalite e acidente vascular cerebral. Estratégias de prevenção poderão mudar a morbi-mortalidade desta condição no paciente portador de doença falciforme.Sickle cell disease due to shortened life span of red blood cells by hemolysis, may present with severe anemia when erythropoietic suppression occurs due to infection by the Human parvovirus B19. The clinical presentation presents with fever, which may precede transient red cell aplasia, as well as laboratorial signs such as a drop in hemoglobin and significant reticulo cytopenia. Laboratorial diagnosis may be by immunofluorescence or enzymatic assays. Treatment is achieved by transfusion of packed red blood cells. Complications may be associated to this infection, including splenic and hepatic sequestration, acute chest syndrome, nephrotic syndrome, meningoencephalitis and strokes. Strategies of prevention are able to change the morbidity and mortality of this condition in sickle cell disease patients.

  17. Uterine horn aplasia with complications in two mixed-breed bitches : case report

    Directory of Open Access Journals (Sweden)

    M.L. Schulman

    1997-07-01

    Full Text Available Unilateral segmental uterine horn aplasia was found in 2 mixed-breed bitches. The 1st bitch was presented with clinical signs of acute abdominal pain, and pyometra was suspected. Pyometra was confirmed surgically with rupture of a blind-ending cranial portion of the anomalous right uterine horn, which had resulted in peritonitis. The 2nd bitch was presented for routine ovariohysterectomy. The right uterine horn was affected by segmental aplasia, with mucometra of the cranial portion of the affected horn. Histopathology demonstrated both uteri to have diffuse cystic endometrial hyperplasia. It is postulated that cystic endometrial hyperplasia, together with the congenital anomaly, resulted in pyometra in one case and in mucometra in the other case. This is believed to be the 1st report of uterine horn aplasia in the bitch in association with clinical signs and lesions other than infertility.

  18. A Patient with Unilateral Tibial Aplasia and Accessory Scrotum: A Pure Coincidence or Nonfortuitous Association?

    Directory of Open Access Journals (Sweden)

    Zoran Gucev

    2010-01-01

    Full Text Available Tibial aplasia is an uncommon lower limb malformation that can occur isolated or be part of a more complex malformation pattern. We describe a 9-year-old boy born after uneventful pregnancy and delivery. Family history was negative for maternal diabetes and other malformations. The patient presented with left tibial aplasia and homolateral prexial foot polydactyly. He also displayed enamel dysplasia and bifid scotum with cryptorchidism. Literature review failed to identify a significant syndromic association between lower limb defects of the tibial type and the genital anomalies reported here. The combination of tibial aplasia with midline genital malformations further supports the hypothesis that the tibial ray development mirrors the morphogenetic process of the radial structures. Accordingly, the malformation pattern observed in the present patient may be pathogenetically explained by an insult occurring during late blastogenesis.

  19. Bone marrow aplasia and severe skin rash after a single low dose of methotrexate.

    Science.gov (United States)

    Copur, S; Dahut, W; Chu, E; Allegra, C J

    1995-02-01

    A 64 year old man with recurrent metastatic squamous cell carcinoma of the head and neck developed severe skin rash and bone marrow aplasia 4 and 7 days, respectively, following a single dose of 40 mg/m2 methotrexate (MTX). Skin rash involved regions of the face, lower abdomen, back, buttocks and both upper thighs. Biopsy of the skin rash demonstrated superficial perivascular lymphocytic infiltrate and was consistent with a drug reaction. Peripheral blood count revealed pancytopenia and a bone marrow biopsy was consistent with aplasia. Blood counts returned to normal 6 days after institution of granulocyte colony stimulating factor therapy. In the absence of mucositis or diarrhea, severe dermatologic toxicity following a single low dose of the drug suggests an 'allergic' or acute hypersensitivity reaction to MTX in this patient. Development of an extensive skin rash following a single dose of MTX may be an early warning sign for life-threatening bone marrow aplasia. PMID:7538828

  20. Congenital aplasia of the optic chiasm and esophageal atresia: a case report

    Directory of Open Access Journals (Sweden)

    Madonia Maurizio

    2011-08-01

    Full Text Available Abstract Introduction The complete absence of the chiasm (chiasmal aplasia is a rare clinical condition. Hypoplasia of the optic nerve and congenital nystagmus are almost invariably associated characteristics. Microphthalmos or anophthalmos are common features in chiasmal aplasia, while central nervous system abnormalities are less frequent. Esophageal atresia can be isolated or syndromic. In syndromic cases, it is frequently associated with cardiac, limb, renal or vertebral malformations and anal atresia. More rarely, esophageal atresia can be part of anophthalmia-esophageal-genital syndrome, which comprises anophthalmia or microphthalmia, genital abnormalities, vertebral defects and cerebral malformations. Here, a previously unreported case of chiasmal aplasia presenting without microphthalmos and associated with esophageal atresia is described. Case presentation Aplasia of the optic chiasm was identified in a Caucasian Italian 8-month-old boy with esophageal atresia. An ultrasound examination carried out at 21 weeks' gestation revealed polyhydramnios. Intrauterine growth retardation, esophageal atresia and a small atrial-septal defect were subsequently detected at 28 weeks' gestation. Repair of the esophageal atresia was carried out shortly after birth. A jejunostomy was carried out at four months to facilitate enteral feeding. The child was subsequently noted to be visually inattentive and to be neurodevelopmentally delayed. Magnetic resonance imaging revealed chiasmal aplasia. No other midline brain defects were found. His karyotype was normal. Conclusion If achiasmia is a spectrum, our patient seems to depict the most severe form, since he appears to have an extremely severe visual impairment. This is in contrast to most of the cases described in the literature, where patients maintain good--or at least useful-- visual function. To the best of our knowledge, the association of optic nerve hypoplasia, complete chiasmal aplasia, esophageal

  1. Reticulocyte maturity index by flow cytometry: its applicability in radioinduced bone marrow aplasia

    International Nuclear Information System (INIS)

    Flow cytometric reticulocyte quantification was assayed in ten patients undergoing bone marrow transplantation (BMT) with previous conditioning chemotherapy and total body irradiation (TBI). A reticulocyte maturity index (RMI) was determined taking into account the RNA content. With de aim of testing the utility of RMI as an early predictor of functional recovery in marrow aplasia, other haematological indicators as neutrophils count were comparatively evaluated. Mean time elapsed between BMT and engraftment evidence by RMI was 17,6 days. In six patients the RMI was the earliest indicator of functional recovery. The applicability of this assay in the following of radioinduced bone marrow aplasia is discussed. (author). 4 refs., 4 figs., 2 tabs

  2. Chronic renal failure due to unilateral renal agenesis and total renal dysplasia (=aplasia)

    International Nuclear Information System (INIS)

    Three adult patients with unilateral renal agenesis/total dysplasia (= aplasia) and with an early chronic renal failure are presented. One patient had renal agenesis without ureter bud and ureteric ostium on one side, and reflux pyelonephritis on the other; one had small compact total renal dysplasia (= aplasia) on one side, while chronic uric acid nephropathy (chronic renal disease as a cause of gout) was diagnosed on the other; the third patient had a total large multicystic dysplasia on one side, and on the other a segmental large multicystic dysplasia. Radiological steps and radiodiagnostic criteria are discussed and the combination of urogenital and extraurogenital anomalies is referred to. (orig.)

  3. Chronic renal failure due to unilateral renal agenesis and total renal dysplasia (=aplasia)

    Energy Technology Data Exchange (ETDEWEB)

    Kroepelin, T.; Ziupa, J.; Wimmer, B.

    1983-05-01

    Three adult patients with unilateral renal agenesis/total dysplasia (= aplasia) and with an early chronic renal failure are presented. One patient had renal agenesis without ureter bud and ureteric ostium on one side, and reflux pyelonephritis on the other; one had small compact total renal dysplasia (= aplasia) on one side, while chronic uric acid nephropathy (chronic renal disease as a cause of gout) was diagnosed on the other; the third patient had a total large multicystic dysplasia on one side, and on the other a segmental large multicystic dysplasia. Radiological steps and radiodiagnostic criteria are discussed and the combination of urogenital and extraurogenital anomalies is referred to.

  4. Holoprosencephaly and Pure Red Cell Aplasia in a Feline Leukaemia Virus-Positive Kitten.

    Science.gov (United States)

    Southard, T L; Rodriguez-Ramos Fernandez, J; Priest, H; Stokol, T

    2016-01-01

    A 9-month-old, female, domestic longhair cat with severe anaemia tested positive for feline leukaemia virus (FeLV) and was humanely destroyed and submitted for necropsy examination. Gross findings included a non-divided rostral telencephalon, consistent with semilobar holoprosencephaly. Histological examination of the bone marrow revealed an almost complete absence of erythroid precursor cells, consistent with pure red cell aplasia, and mild to moderate myelofibrosis. This case demonstrates a very unusual central nervous system defect, as well as an atypical presentation of pure red cell aplasia, in a FeLV-positive kitten. PMID:26897097

  5. Flow cytometric of reticulocytes quantification: radio-induction medullary aplasia application

    International Nuclear Information System (INIS)

    Flow cytometric reticulocyte quantification was assayed in ten patients undergoing bone marrow transplantation (BMT) with previous conditioning by chemotherapy and total body irradiation. A reticulocyte maturity index (RMI) was determined taking into account the RNA content. With the aim of testing the utility of RMI as an early predictor of functional recovery in marrow aplasia, other hematological indicators as neutrophils count were comparatively evaluated. Mean time elapsed between BMT and engraftment evidence by RMI was 17,6 days. In six patients the RMI was the earliest indicator of functional recovery. The applicability of this assay in the pursuit of radioinduced bone marrow aplasia is discussed. (authors). 4 refs., 4 figs., 2 tabs

  6. Networks, Irreversibility and Knowledge Creation.

    OpenAIRE

    Patrick Llerena; Muge Ozman

    2010-01-01

    The aim of this paper is to highlight the effect of irreversibility in partner choice in strategic alliances. In an environment where firms are binded by contractual constraints regarding the duration of partnerships, how does the complexity of products influence the overall knowledge in the industry? Through an agent based simulation model, we compare the knowledge generation in irreversible and reversible systems in two regimes as tacit and codified. The emerging network structures are also...

  7. Tumor Ablation with Irreversible Electroporation

    OpenAIRE

    Al-Sakere, Bassim; André, Franck,; Bernat, Claire; Connault, Elisabeth; Opolon, Paule; Davalos, Rafael V.; Rubinsky, Boris; Mir, Lluis M.

    2007-01-01

    We report the first successful use of irreversible electroporation for the minimally invasive treatment of aggressive cutaneous tumors implanted in mice. Irreversible electroporation is a newly developed non-thermal tissue ablation technique in which certain short duration electrical fields are used to permanently permeabilize the cell membrane, presumably through the formation of nanoscale defects in the cell membrane. Mathematical models of the electrical and thermal fields that develop dur...

  8. Reconstruction of bilateral tibial aplasia and split hand-foot syndrome in a father and daughter

    Directory of Open Access Journals (Sweden)

    Ali Al Kaissi

    2014-01-01

    Full Text Available Background: Tibial aplasia is of heterogeneous aetiology, the majority of reports are sporadic. We describe the reconstruction procedures in two subjects - a daughter and father manifested autosomal dominant (AD inheritance of the bilateral tibial aplasia and split hand-foot syndrome. Materials and Methods: Reconstruction of these patients required multiple surgical procedures and orthoprosthesis was mandatory. The main goal of treatment was to achieve walking. Stabilization of the ankle joint by fibular-talar-chondrodesis on both sides, followed by bilateral Brown-procedure at the knee joint level has been applied accordingly. Results: The outcome was with improved function of the deformed limbs and walking was achieved with simultaneous designation of orthotic fitting. Conclusion: This is the first study encompassing the diagnosis and management of a father and daughter with bilateral tibial aplasia associated with variable split hand/foot deformity without foot ablation. Our patients showed the typical AD pattern of inheritance of split-hand/foot and tibial aplasia.

  9. RETREATMENT WITH FLUDARABINE AND CYCLOSPORINE FOR ONE CASE OF REFRACTORY PURE RED CELL APLASIA

    Institute of Scientific and Technical Information of China (English)

    Guang-sheng He; Xiang Zhang; De-pei Wu; Ai-ning Sun; Miao Miao; Xiu-li Wang; Zheng-ming Jin

    2008-01-01

    @@ MANY cases of pure red cell aplasia (PRCA) were mediated by over-function of immune cells, and responded well to immunosuppres-sive therapy.1 Sometimes refractory cases also arose. Fludara-bine is an analogue of adenosine resistant to deamination which is widely used for B-chronic lymphocytic leukemia (CLL) and other hematological malignancies.

  10. APLASIA CUTIS CONGENITAL WITH AMNIOTIC BAND DISRUPTION COMPLEX: A RARE CASE REPORT

    Directory of Open Access Journals (Sweden)

    Pradipprava

    2015-09-01

    Full Text Available Aplasia cutis congenita (ACC is congenital absence of skin, most commonly affecting scalp. Etiology is multifactorial like intrauterine infection, teratogens, vascular causes, genetic syndromes etc. We here represent an infant with ACC involving extremities and associated with amniotic band disruption complex. He was treated conservatively and discharged.

  11. Tumor ablation with irreversible electroporation.

    Directory of Open Access Journals (Sweden)

    Bassim Al-Sakere

    Full Text Available We report the first successful use of irreversible electroporation for the minimally invasive treatment of aggressive cutaneous tumors implanted in mice. Irreversible electroporation is a newly developed non-thermal tissue ablation technique in which certain short duration electrical fields are used to permanently permeabilize the cell membrane, presumably through the formation of nanoscale defects in the cell membrane. Mathematical models of the electrical and thermal fields that develop during the application of the pulses were used to design an efficient treatment protocol with minimal heating of the tissue. Tumor regression was confirmed by histological studies which also revealed that it occurred as a direct result of irreversible cell membrane permeabilization. Parametric studies show that the successful outcome of the procedure is related to the applied electric field strength, the total pulse duration as well as the temporal mode of delivery of the pulses. Our best results were obtained using plate electrodes to deliver across the tumor 80 pulses of 100 micros at 0.3 Hz with an electrical field magnitude of 2500 V/cm. These conditions induced complete regression in 12 out of 13 treated tumors, (92%, in the absence of tissue heating. Irreversible electroporation is thus a new effective modality for non-thermal tumor ablation.

  12. Extensa falha cutânea e craniana em paciente com aplasia cutis congenita Large scalp and skull defect in patient with aplasia cutis congenita

    Directory of Open Access Journals (Sweden)

    José Gilberto de Brito Henriques

    2004-12-01

    Full Text Available Aplasia cutis congenita (ACC é doença rara, caracterizada pela ausência de formação completa da pele. Geralmente ocorre no couro cabeludo, na linha mediana, e apresenta-se ao nascimento como uma ferida ulcerada que pode atingir diferentes profundidades e envolver o periósteo, crânio e dura-máter. Descrevemos o caso de menina recem-nascida que apresentava fácies dismórfica com defeito no couro cabeludo que abrangia a quase totalidade da abóbada craniana e apresentava falha óssea desde a base dos ossos frontais até os occipitais e mastóides. A dura-máter estava em sua maior parte exposta, sem sinais de fissuras. Devido à raridade da ACC e ao pequeno número de pacientes nas séries publicadas na literatura a padronização do tratamento ainda é incipiente. O que existem são recomendações. Ainda são necessários estudos que abordem desde a etiologia da doença até a avaliação dos métodos de tratamento e evolução de grupos maiores de pacientes.Aplasia cutis congenita is a rare condition characterized by the absence of skin layers. It is most common on the scalp, middle line, and it can be seen as a congenital ulcer involving periosteum, skull and dura. We present the case of a female newborn infant with a dysmorphic facies, a large scalp and skull defect exposing the dura. There was no cerebrospinal fluid leakage. The rarity of cases with large defects and small series reported make difficult to determinate the ideal treatment for aplasia cutis congenita. More studies are necessary to define the etiology and best management of this patients.

  13. [Bilateral deep venous thrombosis and vena cava aplasia treated with local thrombolysis

    DEFF Research Database (Denmark)

    Pelta, A.M.; Jørgensen, Maja; Just, Sven Richardt Lundgren; Jensen, Leif Pandora

    2008-01-01

    In this case report the treatment of a young man with bilateral iliaco-femoral DVT and vena cava aplasia is presented. The patient was treated with catheter-directed thrombolysis; the catheters were introduced in the thrombus of both legs via v. popliteae. The treatment led to almost complete thr...... thrombus resolution and no valvular incompetence at three months follow-up. In our opinion this treatment should be offered even in complex cases of acute proximal deep venous thrombosis Udgivelsesdato: 2008/5/19......In this case report the treatment of a young man with bilateral iliaco-femoral DVT and vena cava aplasia is presented. The patient was treated with catheter-directed thrombolysis; the catheters were introduced in the thrombus of both legs via v. popliteae. The treatment led to almost complete...

  14. Pulmonary Sequestration with Renal Aplasia and Elevated SUV Level in PET/CT

    Directory of Open Access Journals (Sweden)

    Serdar Şen

    2012-01-01

    Full Text Available Extralobar sequestration with other bronchopulmonary malformations is commonly seen; however, the association of extralobar sequestration with renal aplasia is very rare. A 75-year-old female patient was admitted with back pain. Ultrasonography revealed aplasia of the left kidney and tomography showed 6×4.5 cm sized tumor in the left hemithorax at the posterobasal area. The lesion has focally increased glycolytic activity (SUVmax: 3.2 at the left upper pole on positron emission tomography scan (PET/CT. Sequestrectomy was performed after the confirmation by frozen section that the lesion was benign and of extrapulmonary sequestration. No complication occurred during postoperative and 50-month follow-up period.

  15. Segmental aplasia of the uterine horn with ipsilateral renal agenesis in a cat.

    Science.gov (United States)

    Chang, Jinhwa; Jung, Joo-hyun; Yoon, Junghee; Choi, Min-cheol; Park, Jae Hak; Seo, Kang-Moon; Jeong, Seong Mok

    2008-06-01

    A nine-month-old domestic short haired cat was admitted with the history of acute vomiting, depression and shivering. Abdominal ultrasonography revealed minimum enlargement of the right uterine horn filled with anechoic fluid. On excretory urography, functionally and anatomically normal, enlarged left kidney was found, but right kidney was absent. It was preliminary diagnosed as hydrometra with right renal agenesis. Aiming at the correction of hydrometra, we performed ovariohysterectomy. During spaying, we found a missing segment of distal part of the right uterine horn and absence of ipsilateral kidney and ureter. Compressed uterine structure and segmental aplasia of right uterine horn were found in histopathological investigation. Taken together, it was diagnosed as a segmental aplasia of uterine horn with ipsilateral renal agenesis. PMID:18628611

  16. Anti-Erythropoietin Antibody Associated Pure Red Cell Aplasia Resolved after Liver Transplantation

    OpenAIRE

    Hung, Annie K.; Jennifer Guy; Behler, Caroline M.; Lee, Eugene E.

    2015-01-01

    Patients undergoing antiviral therapy for chronic hepatitis C often develop anemia secondary to ribavirin and interferon. Recombinant erythropoietin has been used to improve anemia associated with antiviral therapy and to minimize dose reductions, which are associated with decreased rates of sustained virologic response. A rare potential side effect of recombinant erythropoietin is anti-erythropoietin antibody associated pure red cell aplasia. In chronic kidney disease patients with this enti...

  17. Etanercept-Associated Transient Bone Marrow Aplasia: A Review of the Literature and Pathogenetic Mechanisms

    OpenAIRE

    Kozak, Natasha; Friedman, Joshua; Schattner, Ami

    2014-01-01

    A patient with rheumatoid arthritis presented with increasing fatigue, fever, gingival bleeding, and petechial rash. Her symptoms started 1 week after the first injection of etanercept (Enbrel). Her only other medications (methotrexate and hydroxychloroquine) had been unchanged for years. Tests revealed severe pancytopenia and bone marrow aplasia. She recovered with supportive treatment within 12 days. The literature on serious blood dyscrasias associated with anti-tumor necrosis factor-α the...

  18. Ideally Efficient Irreversible Molecular Gears

    OpenAIRE

    Sokolov, I. M.

    2000-01-01

    Typical man-made locomotive devices use reversible gears, as cranks, for transforming reciprocating motion into directed one. Such gears are holonomic and have the transduction efficiency of unity. On the other hand, a typical gear of molecular motors is a ratchet rectifier, which is irreversible. We discuss what properties of rectifier mostly influence the transduction efficiency and show that an apliance which locks under backwards force can achieve the energetic efficiency of unity, withou...

  19. Irreversible Does Not Mean Unavoidable

    OpenAIRE

    Matthews, H.D.; Solomon, Susan

    2013-01-01

    Understanding how decreases in CO[subscript 2] emissions would affect global temperatures has been hampered in recent years by confusion regarding issues of committed warming and irreversibility. The notion that there will be additional future warming or “warming in the pipeline” if the atmospheric concentrations of carbon dioxide were to remain fixed at current levels (1) has been misinterpreted to mean that the rate of increase in Earth's global temperature is inevitable, regardless of how ...

  20. Irreversible Electroporation of Hepatic Malignancy

    OpenAIRE

    Narayanan, Govindarajan; Froud, Tatiana; Suthar, Rekhaben; Barbery, Katuska

    2013-01-01

    Hepatocellular carcinoma (HCC) is a worldwide problem of epidemic proportions, best treated in a multidisciplinary setting. Major advances have been made in all specialties that manage patients with HCC, with surgical options at one end of the spectrum and palliative chemotherapy on the other, and the vast majority of patients require the involvement and expertise of interventional oncology. Several ablative and transarterial technologies are currently available. Irreversible electroporation ...

  1. Thermodynamic optimization of irreversible refrigerators

    International Nuclear Information System (INIS)

    Highlights: • Dimensionless equation that links COP, entropy rate variation and heat exchange. • Maximum COP as function of parameter controlling thermal exchanges. • Application at irreversible vapor compression refrigerator based on literature data. • Results show the analysis is useful in diagnostic and designing of refrigerators. - Abstract: An irreversible inverse cycle, operating at steady state conditions with finite thermal capacity heat sources, is analyzed in order to obtain an expression for the coefficient of performance accounting for the Second Law. Some dimensionless parameters are proposed to link the entropy variation rate and the temperature differences at the heat exchangers to the cycle efficiency. A maximum for efficiency appears when a parameter depending only on the temperature of the inlet streams at each heat exchanger is used. The influence of dimensionless parameters and irreversibilities on the maximum cycle efficiency is analyzed. A graphical analysis, based on data from literature, is presented to show the use of this thermodynamic optimization criteria in design and verification process of refrigerators

  2. Irreversibility in asymptotic manipulations of entanglement

    OpenAIRE

    Vidal, G.; Cirac, J. I.

    2001-01-01

    We show that the process of entanglement distillation is irreversible by showing that the entanglement cost of a bound entangled state is finite. Such irreversibility remains even if extra pure entanglement is loaned to assist the distillation process.

  3. Ecological optimization for generalized irreversible Carnot refrigerators

    International Nuclear Information System (INIS)

    The optimal ecological performance of a Newton's law generalized irreversible Carnot refrigerator with the losses of heat resistance, heat leakage and internal irreversibility is derived by taking an ecological optimization criterion as the objective, which consists of maximizing a function representing the best compromise between the exergy output rate and exergy loss rate (entropy production rate) of the refrigerator. Numerical examples are given to show the effects of heat leakage and internal irreversibility on the optimal performance of generalized irreversible refrigerators

  4. Information symmetries in irreversible processes

    Science.gov (United States)

    Ellison, Christopher J.; Mahoney, John R.; James, Ryan G.; Crutchfield, James P.; Reichardt, Jörg

    2011-09-01

    We study dynamical reversibility in stationary stochastic processes from an information-theoretic perspective. Extending earlier work on the reversibility of Markov chains, we focus on finitary processes with arbitrarily long conditional correlations. In particular, we examine stationary processes represented or generated by edge-emitting, finite-state hidden Markov models. Surprisingly, we find pervasive temporal asymmetries in the statistics of such stationary processes. As a consequence, the computational resources necessary to generate a process in the forward and reverse temporal directions are generally not the same. In fact, an exhaustive survey indicates that most stationary processes are irreversible. We study the ensuing relations between model topology in different representations, the process's statistical properties, and its reversibility in detail. A process's temporal asymmetry is efficiently captured using two canonical unifilar representations of the generating model, the forward-time and reverse-time ɛ-machines. We analyze example irreversible processes whose ɛ-machine representations change size under time reversal, including one which has a finite number of recurrent causal states in one direction, but an infinite number in the opposite. From the forward-time and reverse-time ɛ-machines, we are able to construct a symmetrized, but nonunifilar, generator of a process—the bidirectional machine. Using the bidirectional machine, we show how to directly calculate a process's fundamental information properties, many of which are otherwise only poorly approximated via process samples. The tools we introduce and the insights we offer provide a better understanding of the many facets of reversibility and irreversibility in stochastic processes.

  5. Niche Applications of Irreversible Electroporation.

    Science.gov (United States)

    Bhatia, Shivank S; Arya, Rahul; Narayanan, Govindarajan

    2015-09-01

    Irreversible electroporation (IRE) induces cell death by exposing it to high-voltage, low-energy DC current pulses. The mechanism of cell death and healing is a departure from the other existing technologies such as radiofrequency ablation, microwave ablation, and cryoablation. These thermal ablative technologies have several applications in oncology but have limitations that have also been established. IRE has shown promise to overcome some of these limitations and has enabled the use of an ablative technology in treating lesions close to the bile ducts and vasculature and in organs such as the pancreas. This review highlights some of the niche applications of IRE and the data so far. PMID:26365547

  6. Quantum mechanical irreversibility and measurement

    CERN Document Server

    Grigolini, P

    1993-01-01

    This book is intended as a tutorial approach to some of the techniques used to deal with quantum dissipation and irreversibility, with special focus on their applications to the theory of measurements. The main purpose is to provide readers without a deep expertise in quantum statistical mechanics with the basic tools to develop a critical judgement on whether the major achievements in this field have to be considered a satisfactory solution of quantum paradox, or rather this ambitious achievement has to be postponed to when a new physics, more general than quantum and classical physics, will

  7. A case of severe congenital kyphoscoliosis secondary to multiple bilateral thoracic pedicle aplasia

    Energy Technology Data Exchange (ETDEWEB)

    Geoffray, Anne; Leloutre, Beatrice; Albertario, Marco; Bechard-Sevette, Nancy [Fondation Lenval Children' s Hospital, Department of Pediatric Imaging, Nice (France); Clement, Jean-Luc [Fondation Lenval Children' s Hospital, Department of Orthopedic and Spine Surgery, Nice (France)

    2008-07-15

    A 9-month-old boy with congenital kyphoscoliosis secondary to multiple bilateral thoracic pedicle aplasias is presented. This anomaly has rarely been described in the literature. Plain films showed absence of thoracic pedicles bilaterally from T2 to T9, which was better demonstrated on CT multiplanar and 3-D reformatted images. There were no neurological symptoms even though the deformity progressed rapidly. Congenital kyphosis or kyphoscoliosis is often related to spinal anomalies that are located on the anterior aspect of the vertebrae. However, posterior anomalies may also be responsible and should be recognized before neurological complications occur. (orig.)

  8. [Aplasia and hypoplasia of the side of the nose in the Mocha Period and today].

    Science.gov (United States)

    Pirsig, W

    1989-01-01

    In earthenware vessels from the Moche period (200-700 A.D.) pathological findings of nasal deformities have been depicted in a realistic manner. By means of two recent casuistics and of two portrait vessels of Old Peru it is demonstrated how exactly the nasal pathology was observed by the artists of the Moche period. The first example shows a unilateral hypoplasia of the nasal ala due to injury in early childhood, the second example shows a bilateral aplasia of the nasal alae due to an intrauterine growth disturbance. PMID:2690796

  9. Prenatal ultrasonography of trisomy 18 with radial aplasia: A case report

    International Nuclear Information System (INIS)

    Trisomy 18 (Edward syndrome) is the second most common chromosomal anomaly of the autosomal trisomy. Prenatal diagnosis of trisomy 18 is extremely important because of the complex malformations and lethal prognosis. Prenatal sonographic findings at 17 weeks of gestation showing radial aplasia with upper limb contracture, omphalocele, and suspicious esophageal atresia suggested the diagnosis and led to amniocentesis. Karyotyping revealed trisomy 18 (47 XX, +18, and characteristic autopsy findings were identified. We report a case of prenatally diagnosed trisomy 18 with a review of literatures.

  10. Prenatal ultrasonography of trisomy 18 with radial aplasia: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jee Young; Lee, Yeon Hee [Dankook University College of Medicine, Seoul (Korea, Republic of)

    2002-06-15

    Trisomy 18 (Edward syndrome) is the second most common chromosomal anomaly of the autosomal trisomy. Prenatal diagnosis of trisomy 18 is extremely important because of the complex malformations and lethal prognosis. Prenatal sonographic findings at 17 weeks of gestation showing radial aplasia with upper limb contracture, omphalocele, and suspicious esophageal atresia suggested the diagnosis and led to amniocentesis. Karyotyping revealed trisomy 18 (47 XX, +18, and characteristic autopsy findings were identified. We report a case of prenatally diagnosed trisomy 18 with a review of literatures.

  11. Pure red cell aplasia due to azathioprine therapy for Crohn′s disease

    Directory of Open Access Journals (Sweden)

    Nagesh Kamath

    2016-01-01

    Full Text Available Various mechanisms contribute to anemia in inflammatory bowel diseases (IBD, drug-related causes being less frequent. The hematological and other adverse events of azathioprine (AZA therapy are well documented, but drug-associated pure red cell aplasia (PRCA is an uncommon event. We hereby describe two cases of AZA-associated PRCA in patients with Crohn′s disease. The diagnosis was supported by pathological reports, and prompt hematological recovery was seen with discontinuation of the offending drug. This report highlights the need to consider this rare entity in IBD patients in appropriate settings and for adopting adequate precautionary measures.

  12. Lyapunov decay in quantum irreversibility.

    Science.gov (United States)

    García-Mata, Ignacio; Roncaglia, Augusto J; Wisniacki, Diego A

    2016-06-13

    The Loschmidt echo-also known as fidelity-is a very useful tool to study irreversibility in quantum mechanics due to perturbations or imperfections. Many different regimes, as a function of time and strength of the perturbation, have been identified. For chaotic systems, there is a range of perturbation strengths where the decay of the Loschmidt echo is perturbation independent, and given by the classical Lyapunov exponent. But observation of the Lyapunov decay depends strongly on the type of initial state upon which an average is carried out. This dependence can be removed by averaging the fidelity over the Haar measure, and the Lyapunov regime is recovered, as has been shown for quantum maps. In this work, we introduce an analogous quantity for systems with infinite dimensional Hilbert space, in particular the quantum stadium billiard, and we show clearly the universality of the Lyapunov regime. PMID:27140966

  13. Irreversibility of electrical insulating material properties

    OpenAIRE

    Radek Polansky; Vaclav Mentlik

    2007-01-01

    Property changes in electrical insulating materials that appear during repeated voltage stress (e. g. in an applied voltage test) are an often discussed problem. The voltage exposure leads to irreversible changes in a negative sense as this investigation clearly demonstrates. A slow deterioration appears even in the case of the above mentioned applied voltage test when the irreversible effects of particular measurements superimpose. These are the effects of irreversible behavior of the insula...

  14. Time series irreversibility: a visibility graph approach

    CERN Document Server

    Lacasa, Lucas; Roldán, Édgar; Parrondo, Juan M R; Luque, Bartolo

    2011-01-01

    We propose a method to measure real-valued time series irreversibility which combines two differ- ent tools: the horizontal visibility algorithm and the Kullback-Leibler divergence. This method maps a time series to a directed network according to a geometric criterion. The degree of irreversibility of the series is then estimated by the Kullback-Leibler divergence (i.e. the distinguishability) between the in and out degree distributions of the associated graph. The method is computationally effi- cient, does not require any ad hoc symbolization process, and naturally takes into account multiple scales. We find that the method correctly distinguishes between reversible and irreversible station- ary time series, including analytical and numerical studies of its performance for: (i) reversible stochastic processes (uncorrelated and Gaussian linearly correlated), (ii) irreversible stochastic pro- cesses (a discrete flashing ratchet in an asymmetric potential), (iii) reversible (conservative) and irreversible (di...

  15. A class of internally irreversible refrigeration cycles

    Science.gov (United States)

    Ait-Ali, Mohand A.

    1996-03-01

    A Carnot-like irreversible refrigeration cycle is modelled with two isothermal and two non-adiabatic, irreversible processes. The generic source of internal irreversibility, measured by the Clausius inequality, is a general irreversibility term which could include any heat leaks into the Joule - Thompson expansion valve, the evaporator and compressor cold boxes. This cycle is optimized first for maximum refrigeration power and maximum refrigeration load, then for maximum coefficient of performance. Its performances are compared with those of the endoreversible refrigeration cycle, based on a propane stage of a classical cascade liquefaction cycle example. Both cycle models achieve optimum power and maximum refrigeration load at nearly the same refrigeration temperature, but only the coefficient of performance of the irreversible refrigeration cycle reaches a maximum. Moreover, its prediction of heat conductance allocation between evaporator and condenser appears to be not only more conservative, but also more realistic for actual design considerations of refrigeration cycles.

  16. New experimental approach to treatment of radiation-induced bone marrow aplasia: ex vivo expansion of hematopoietic cells

    International Nuclear Information System (INIS)

    The management of bone marrow aplasia secondary to accidental exposure to high doses of ionizing radiations requires new therapeutic protocols in addition to cytokine therapy. The in vitro incubation of hematopoietic stem and progenitor cells from irradiated nonhuman primates with negative and positive regulators of hematopoiesis may lead to helpful products of transfusion. (author)

  17. Application of Irreversible Thermodynamics to Distillation

    Directory of Open Access Journals (Sweden)

    Signe Kjelstrup

    2004-09-01

    Full Text Available We compare three different ways of modelling tray distillation to each other, and to experimental data: the most common way that assumes equilibrium between the liquid and vapour phases at the outlets of each tray, and two more precise methods that use irreversible thermodynamics. Irreversible thermodynamics determines the driving forces and fluxes of a system in agreement with the second law. It is shown that the methods using irreversible thermodynamics (Maxwell-Stefan equations are superior to the method that assumes that equilibrium is reached on each tray. The Soret effect must be included to have a good description of the heat flux.

  18. Post renal transplant pure red cell aplasia-is tacrolimus a culprit?

    Science.gov (United States)

    Patil, Malagouda R; Choudhury, Arpita Roy; Chohwanglim, Manong; Divyaveer, Smita; Mahajan, Chetan; Pandey, Rajendra

    2016-08-01

    Anemia is not uncommon in the post-renal transplant period and has been reported in up to 40% of renal transplant recipients. It is commonly due to drugs and infections. While post-transplantation anemia is usually due to graft dysfunction and drugs such as mycophenolate and cotrimoxazole, tacrolimus is an uncommon cause. Tacrolimus is usually not believed to be significantly myelosuppressive, but it can cause anemia due to thrombotic microangiopathy. A literature review shows a very small number of reported cases of pure red cell aplasia (PRCA) where tacrolimus seemed to be a causative agent. We report a case series of three renal transplant recipients who were on tacrolimus and presented with chronic transfusion requiring anemia due to PRCA. PMID:27478605

  19. Aplasia cutis congenita of the scalp with large underlying skull defect: a case report

    International Nuclear Information System (INIS)

    Localised agenesis of the scalp is the most frequent patern in aplasia cutis congenita (ACC), a congenital absence of the skin and occasionally of deeper layers. Several clinical groups are characterised by the location and pattern of skin defects, associated malformations and the mode of inheritance. Death occurs in 20 % of cases, secondary to the associated anomalies, to infections or to haemorrhage from ulceration of the sagittal sinus when there is also a defect of the underlying skull. In this latter case, we close the defect by two rotational scalp flaps (Orticochea technique) at birth. A three-dimensional CT study is useful for showing the extent of the skull defect and the deformity of the craniofacial complex and the changes in the bone after treatment. (orig.)

  20. Irreversible thermal denaturation of Torpedo californica acetylcholinesterase.

    OpenAIRE

    Kreimer, D. I.; Shnyrov, V. L.; Villar, E.; Silman, I.; Weiner, L

    1995-01-01

    Thermal denaturation of Torpedo californica acetylcholinesterase, a disulfide-linked homodimer with 537 amino acids in each subunit, was studied by differential scanning calorimetry. It displays a single calorimetric peak that is completely irreversible, the shape and temperature maximum depending on the scan rate. Thus, thermal denaturation of acetylcholinesterase is an irreversible process, under kinetic control, which is described well by the two-state kinetic scheme N-->D, with activation...

  1. Port contact systems for irreversible thermodynamical systems

    OpenAIRE

    Eberard, D.; Maschke, B. M.; Schaft, A.J. van der

    2005-01-01

    In this paper we propose a definition of control contact systems, generalizing input-output Hainiltonian systems, to cope with models arising from irreversible Thermodynamics. We exhibit a particular subclass of these systems, called conservative, that leaves invariant some Legendre submanifold (the geometric structures associated with thermodynamic properties). These systems, both energy-preserving and irreversible, are then used to analyze the loss-lessness of these systems with respect to ...

  2. Fluctuation, Dissipation and Irreversibility in Cosmology

    OpenAIRE

    Hu, B. L.

    1993-01-01

    We discuss the appearance of time-asymmetric behavior in physical processes in cosmology and in the dynamics of the Universe itself. We begin with an analysis of the nature and origin of irreversibility in well-known physical processes such as dispersion, diffusion, dissipation and mixing, and make the distinction between processes whose irreversibility arises from the stipulation of special initial conditions, and those arising from the system's interaction with a coarse-grained environment....

  3. Recurrence of thymoma with pleural invasion in a patient with myasthenia gravis and pure red blood cell aplasia: a case report

    International Nuclear Information System (INIS)

    Thymoma are thymic tumors that arise from epithelial cells, they have different morphological characteristics. It is known for its association with autoimmune diseases such as myasthenia gravis, pure red cell aplasia, systemic lupus erythematosus, or hipogamaglobulinemia pemphigus foliaceus. The association thymoma-myasthenia gravis-pure red cell aplasia is a rare one; there will be a case report with the corresponding discussion and review of the literature

  4. Bacterial, fungal and yeast contamination in six brands of irreversible hydrocolloid impression materials Contaminação por bactérias, fungos e leveduras em seis marcas comerciais de materiais de moldagem à base de hidrocolóide irreversível

    OpenAIRE

    Luciana Assirati Casemiro; Carlos Henrique Gomes Martins; Fernanda de Carvalho Panzeri Pires de Souza; Heitor Panzeri; Isabel Yoko Ito

    2007-01-01

    This study assessed the level of contamination of six commercially available irreversible hydrocolloids (two containing chlorhexidine) and identified the contamination present in the materials. Petri dishes containing selective and enriched culture media were inoculated with alginate powder (0.06 g), in triplicate. After incubation (37°C/7 days), the colony-forming units (CFU) were counted and Gram stained. Biochemical identification of the different morphotypes was also performed. The co...

  5. Incidental finding of unilateral isolated aplasia of serratus anterior muscle and winged scapula on chest radiograph: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Joon Sung; Park, Hyun Jin; Ko, Jeong Min [Dept. of Radiology, St. Vincent' s Hospital, College of Medicine, The Catholic University of Korea, Suwon (Korea, Republic of)

    2014-10-15

    The isolated aplasia of the serratus anterior muscle with winging of scapula is very rare, and only a few cases are reported. Here, we present a case of a 30-year-old Korean male who initially presented with a left flank pain. His physical exam did not show any significant finding in his right shoulder. However, his chest radiograph showed absence of right serratus anterior muscle and slightly elevated and medially rotated right scapula. Subsequent CT scan showed the right serratus anterior muscle aplasia and medial winging of the right scapula. This case is unique in two aspects. First, the combination of abnormalities is different from the typical congenital abnormalities involving shoulder girdle, such as Sprengel deformity or Poland syndrome. Secondly, this was incidentally diagnosed with chest radiograph, without clinical impression. Careful reading of chest radiograph can help the radiologists to detect such clinically silent abnormalities.

  6. MURCS (Müllerian duct aplasia-renal agenesis-cervicothoracic somite dysplasia): a rare cause of primary amenorrhoea.

    Science.gov (United States)

    Kumar, Sunil; Sharma, Shruti

    2016-04-01

    The agenesis of the Müllerian duct is the second most common cause of primary amenorrhoea after Turner syndrome. The abnormal development of Müllerian duct often associates with the urinary tract and skeletal abnormalities. MURCS (Müllerian duct aplasia-renal agenesis-cervicothoracic somite dysplasia) association is a unique and rare developmental disorder with four common features of uterine hypoplasia or aplasia, renal agenesis or ectopy, vertebral anomalies and short stature. We report a case of young female with primary amenorrhoea. She had well-developed secondary sexual characteristics along with multiple congenital developmental abnormalities such as the absence of uterus, ectopic kidney, cervical vertebral fusion, hemivertebrae, scoliosis, cervical rib, facial asymmetry and growth retardation. Our case highlights the rarity and clinical importance of this syndrome. For the evaluation of primary amenorrhoea in a female with well-developed secondary sexual characteristics, congenital anomalies should be ruled out before hormone and karyotype analyses. PMID:27099773

  7. Incidental finding of unilateral isolated aplasia of serratus anterior muscle and winged scapula on chest radiograph: A case report

    International Nuclear Information System (INIS)

    The isolated aplasia of the serratus anterior muscle with winging of scapula is very rare, and only a few cases are reported. Here, we present a case of a 30-year-old Korean male who initially presented with a left flank pain. His physical exam did not show any significant finding in his right shoulder. However, his chest radiograph showed absence of right serratus anterior muscle and slightly elevated and medially rotated right scapula. Subsequent CT scan showed the right serratus anterior muscle aplasia and medial winging of the right scapula. This case is unique in two aspects. First, the combination of abnormalities is different from the typical congenital abnormalities involving shoulder girdle, such as Sprengel deformity or Poland syndrome. Secondly, this was incidentally diagnosed with chest radiograph, without clinical impression. Careful reading of chest radiograph can help the radiologists to detect such clinically silent abnormalities.

  8. Ex vivo expansion of haematopoietic cells in the treatment of accidental irradiation-induced aplasia. Feasibility Studies

    International Nuclear Information System (INIS)

    The lessons learnt from the treatment of previous radiation accidents using either bone marrow transplantation or growth factor therapy suggest that it is of importance to investigate new therapeutic regiments. Ex vivo expansion of haematopoietic stem cells, precursors and differentiated cells is a new approach of growth factor therapy which may be of interest for the treatment of patients with irradiation-induced bone marrow aplasia. Ex vivo expanded maturing cells could be used to limit the early risks bound to aplasia (infections related to granulocytopaenia, bleedings associated with thrombocytopaenia), whereas expanded immature cells could hasten haematopoietic recovery. Indeed, it is possible to culture from the blood or bone marrow the cells able to proliferate and differentiate. A sufficient quantity of cells to cover the transfusion needs of a radiation victim through an aplasia episode can be produced, in presence of a specific growth factor combination. Qualitative studies shows that the expanded cells exhibit a close to normal functionality. Long-term culture techniques demonstrate the expansion of immature cells. We have set up a high dose total body irradiation non-human primate model in order to study the therapeutic potential of ex vivo expansion of autologous progenitors and differentiating cells. All the steps of the process (sampling, positive selection of the immature cells, ex vivo expansion, irradiation of the animals, reinjection of the cultured cells and study of the outcome) are established. In order to allow the long term follow up of the ex vivo expanded haematopoietic cells (homing to the bone marrow or localization to specific organs for example), a retroviral gene transfer technique for transduction of green fluorescence protein (GFP) gene toward the selected immature blood or bone marrow cells is under development in this model. Taken together these elements will allow establishing the feasibility of ex vivo expansion of

  9. Ostwald ripening of precipitates and irreversible phenomena

    International Nuclear Information System (INIS)

    In principle, the manner according to which a phase transformation proceeds should be determinable by irreversible thermodynamics just as well as by appropriate kinetic equations embodying the transport of matter or energy. In practice, however, the former is seldom invoked and the latter approach provides the exclusive description of the transformation leaving one wondering what role the former plays. In this paper, the problem of Ostwald ripening of precipitates is studied to throw light on the underlying irreversible thermodynamics. From a path integral solution, it is shown that the size distribution evolves in such a manner that a Lagrangian is minimized. This Lagrangian is the sum of the dissipation potentials in the flux and force representations minus the rate of entropy production. The coarsening process proceeds in accordance with Onsager's principle of least dissipation. The implications of this study in relation to other irreversible phenomena are also discussed

  10. Fluctuation, Dissipation and Irreversibility in Cosmology

    CERN Document Server

    Hu, B L

    1993-01-01

    We discuss the appearance of time-asymmetric behavior in physical processes in cosmology and in the dynamics of the Universe itself. We begin with an analysis of the nature and origin of irreversibility in well-known physical processes such as dispersion, diffusion, dissipation and mixing, and make the distinction between processes whose irreversibility arises from the stipulation of special initial conditions, and those arising from the system's interaction with a coarse-grained environment. We then study the irreversibility associated with quantum fluctuations in cosmological processes like particle creation and the `birth of the Universe'. We suggest that the backreaction effect of such quantum processes can be understood as the manifestation of a fluctuation-dissipation relation relating fluctuations of quantum fields to dissipations in the dynamics of spacetime. For the same reason it is shown that dissipation is bound to appear in the dynamics of minisuperspace cosmologies. This provides a natural cours...

  11. Absence of Clinical and Hemodynamic Consequences due to Posterior Tibial Artery Congenital Aplasia

    Directory of Open Access Journals (Sweden)

    Georgios Karaolanis

    2015-01-01

    Full Text Available The exact knowledge of popliteal artery and its branches’ anatomic variations is important for the clinical practice of angiology, vascular surgery, and interventional procedures. Congenital absence of the artery leads, in some cases, to early malformations of the extremity in the childhood; however, it may also remain asymptomatic. We present an unusual case of a 76-year-old male patient complaining of paraesthesia in both limbs and bilateral aplasia of posterior tibial artery (PTA. Physical examination, ankle-brachial indexes, before and after exercise, arterial duplex scan, and magnetic resonance arteriography were performed. Arterial pulses for PTA at the level of the ankle were normal; arterial duplex study showed biphasic arterial flow at the level of the ankle. Color duplex ultrasound as well as magnetic resonance arteriography revealed the absence of the PTA in both limbs. The vascularization of the fibula was bilaterally normal. The patient underwent also neurological examination and electromyography, which were normal. The evaluation of the possible clinical signs and symptoms and the hemodynamic consequences of this condition are further discussed.

  12. Spontaneous hematologic recovery from bone marrow aplasia after accidental tenfold overdosage with radiophosphorus

    Energy Technology Data Exchange (ETDEWEB)

    Gmuer, J.; Bischof, B.; Coninx, S.; Bucher, U.; Poretti, G.; Henrichs, K.; Kaul, A.; Roedler, H.D.; Buettner, K.; Frick, P.G.

    1983-04-01

    Two patients with polycythemia vera received intravenously an accidental tenfold overdosage of radiophosphorus therapy (60 and 50 mCi 32P, respectively). In both patients, the occurrence of hemorrhagic complications 3 wk after the 32P medication led to detection of the error and referral to our hospital. Upon admission they showed an agranulocytosis, severe thrombocytopenia, and bone marrow aplasia. In both cases, spontaneous recovery of the hematopoiesis was observed from day 40 posttreatment onward. In one patient, a slow but ultimately complete normalization of blood counts and marrow morphology took place, whereas in the other, a mild thrombocytopenia persists. Nearly 5 yr after the accidental overdosage, both patients are clinically well. Symptoms of polycythemia vera have not reappeared up to now. Attempts were made to evaluate the radiation dose absorbed by the bone marrow. In the first patient, the daily 32P excretion was determined from day 22 to day 60, whereas in the other patient a whole body count was performed on day 78 after administration. From these results, an approximate cumulative bone marrow dose of 10 Sv (1000 rem) could be calculated.

  13. Unilateral multifocal testicular biopsies in 320 patients with germ cell aplasia

    Directory of Open Access Journals (Sweden)

    D Jamali Zavareii. M

    2007-05-01

    Full Text Available Background: Germ cell aplasia (G.C.A is one of the most important testicular causes of infertility and azospermia.In this condition the seminiferous tubules are only lined by a single layer of sertoli cell. In some cases, there is focal area with spermatogenic activity. Methods: We studied infertile men with G.C.A referred to Jahade Daneshgahi of Iran during 1381-82, retrospectively. All the cases had more than one biopsy of one testis. Results: In 11.6٪ of 320 cases, comparison of multiple biopsy sites of a testis revealed: when one site showed G.C.A, another site revealed areas with spermatogenic activity. Considering the cases who showed germ cells in both sites, 15.3٪ of cases multiple biopsy sites appeared to have focal spermatogenesis, better maturation of germ cells or higher scoring area for urologic operation. Conclusion: According to new techniques in treatment of infertility with ICSI (intra cytoplasmic sperm injection in which fertility is possible with one spermatozoa or even spermatid (after recovery, biopsy of multiple sites instead of only one site is highly recommended in azospermic patient.

  14. The reverse control of irreversible biological processes.

    Science.gov (United States)

    Cho, Kwang-Hyun; Joo, Jae Il; Shin, Dongkwan; Kim, Dongsan; Park, Sang-Min

    2016-09-01

    Most biological processes have been considered to be irreversible for a long time, but some recent studies have shown the possibility of their reversion at a cellular level. How can we then understand the reversion of such biological processes? We introduce a unified conceptual framework based on the attractor landscape, a molecular phase portrait describing the dynamics of a molecular regulatory network, and the phenotype landscape, a map of phenotypes determined by the steady states of particular output molecules in the attractor landscape. In this framework, irreversible processes involve reshaping of the phenotype landscape, and the landscape reshaping causes the irreversibility of processes. We suggest reverse control by network rewiring which changes network dynamics with constant perturbation, resulting in the restoration of the original phenotype landscape. The proposed framework provides a conceptual basis for the reverse control of irreversible biological processes through network rewiring. WIREs Syst Biol Med 2016, 8:366-377. doi: 10.1002/wsbm.1346 For further resources related to this article, please visit the WIREs website. PMID:27327189

  15. Risk Aversion, Price Uncertainty and Irreversible Investments

    NARCIS (Netherlands)

    van den Goorbergh, R.W.J.; Huisman, K.J.M.; Kort, P.M.

    2003-01-01

    This paper generalizes the theory of irreversible investment under uncertainty by allowing for risk averse investors in the absence of com-plete markets.Until now this theory has only been developed in the cases of risk neutrality, or risk aversion in combination with complete markets.Within a gener

  16. Mathematical Models and Equilibrium in Irreversible Microeconomics

    OpenAIRE

    Anatoly M. Tsirlin; Sergey A. Amelkin

    2010-01-01

    A set of equilibrium states in a system consisting of economic agents, economic reservoirs, and firms is considered. Methods of irreversible microeconomics are used. We show that direct sale/purchase leads to an equilibrium state which depends upon the coefficients of supply/demand functions. To reach the unique equilibrium state it is necessary to add either monetary exchange or an intermediate firm.

  17. GROUPOIDS AND IRREVERSIBLE DISCRETE DYNAMICAL SYSTEMS II

    Directory of Open Access Journals (Sweden)

    Mădălina Roxana Buneci

    2012-05-01

    Full Text Available The purpose of this paper is to study the topology of the orbit space of an irreversible discrete dynamical system (X,  seen as a principal groupoid associated to the groupoid G(X,,E introduced in [1] (where E is an equivalence relation on X.

  18. Epoetin-associated pure red cell aplasia: past, present, and future considerations

    Science.gov (United States)

    McKoy, June M.; Stonecash, Robin E.; Cournoyer, Denis; Rossert, Jerome; Nissenson, Allen R.; Raisch, Dennis W.; Casadevall, Nicole; Bennett, Charles L.

    2009-01-01

    BACKGROUND Since 1988, millions of patients have received epoetin products intravenously (IV) and subcutaneously. In 1998, epoetin-associated pure red cell aplasia (PRCA) was first reported and causation was attributed to formulations without human serum albumin (HSA), subcutaneous administration, and uncoated rubber stoppers. STUDY DESIGN AND METHODS Data on erythropoietin (EPO)-associated PRCA were obtained from the Food and Drug Administration (FDA), regulatory authorities in other countries, and the manufacturers of epoetin alfa, epoetin beta, and darbepoetin. The data included information on numbers of PRCA cases and estimated exposure-adjusted incidence rates by EPO product, anemia etiology, administration route, country of PRCA identification, and date reported. RESULTS In 1999, academicians in Paris identified 12 EPO-treated patients with antibody-mediated PRCA; 11 of these patients were on hemodialysis and had received subcutaneous Eprex (Johnson & Johnson). In 2002, authorities in Europe, Australia, Singapore, and Canada mandated Eprex by IV route to hemodialysis patients, and the relevant manufacturers added Teflon coating to prefilled syringes of Eprex; PRCA cases subsequently decreased by 90 percent. By 2003, 180 Eprex-associated PRCA cases were identified in Europe, Canada, Australia, and Asia, despite improvements in handling. Since 2002, FDA safety databases include information on 59 new cases of antibody-associated PRCA, primarily associated with subcutaneous epoetin alfa and darbepoetin that does not contain HSA. CONCLUSION Independent actions by regulatory authorities, manufacturers, and academic researchers identified significant numbers of PRCA cases between 1998 and 2003 and characterized the probable etiology. Today, antibody-mediated PRCA is an infrequent class toxicity occurring among some hemodialysis patients on EPOs. PMID:18482185

  19. Aplasia cutis congenita in a setting of fetus papyraceus associated with small fetal abdominal circumference and high alpha-fetoprotein and amniotic acetylcholinesterase.

    Science.gov (United States)

    Mazza, Joni M; Klein, Janice F; Christopher, Kurt; Silverberg, Nanette B

    2015-01-01

    Fetus papyraceus is the fetal death of one or more fetuses in a multiparous pregnancy. The surviving infants can experience extensive aplasia cutis in an H-shaped distribution over the flanks and abdomen as a consequence of the loss of their fetal sibling. We report the case of a monochorionic, diamniotic pregnancy complicated by a single fetal death at 13 weeks of gestational age. Aplasia cutis of the surviving twin was suggested in utero by three criteria: high amniotic and maternal alpha-fetoprotein, detectable acetylcholinesterase, and small abdominal circumference on prenatal ultrasound. This constellation of findings in the setting of fetus papyraceus can be an indicator of aplasia cutis in the surviving fetus. PMID:24118049

  20. Metrics and Energy Landscapes in Irreversible Thermodynamics

    OpenAIRE

    Bjarne Andresen

    2015-01-01

    We describe how several metrics are possible in thermodynamic state space but that only one, Weinhold’s, has achieved widespread use. Lengths calculated based on this metric have been used to bound dissipation in finite-time (irreversible) processes be they continuous or discrete, and described in the energy picture or the entropy picture. Examples are provided from thermodynamics of heat conversion processes as well as chemical reactions. Even losses in economics can be bounded using a therm...

  1. Corporate Tax Asymmetries under Investment Irreversibility

    OpenAIRE

    Panteghini, Paolo

    2001-01-01

    This article studies the effects of corporate tax asymmetries on irreversible investment. We discuss an asymmetric tax scheme where the tax base is given by the firm's return, net of an imputation rate. When the firm's return is less than this rate, however, no tax refunds are allowed. Contrary to common winsdom, this asymmetric scheme may be neutral even when assuming a long-lasting income uncertainty. Neutrality holds even if we add both capital and political uncertainty.

  2. Simulations of kinetically irreversible protein aggregate structure.

    OpenAIRE

    Patro, S Y; Przybycien, T M

    1994-01-01

    We have simulated the structure of kinetically irreversible protein aggregates in two-dimensional space using a lattice-based Monte-Carlo routine. Our model specifically accounts for the intermolecular interactions between hydrophobic and hydrophilic protein surfaces and a polar solvent. The simulations provide information about the aggregate density, the types of inter-monomer contacts and solvent content within the aggregates, the type and extent of solvent exposed perimeter, and the short-...

  3. Mathematical models and equilibrium in irreversible microeconomics

    Directory of Open Access Journals (Sweden)

    Anatoly M. Tsirlin

    2010-07-01

    Full Text Available A set of equilibrium states in a system consisting of economic agents, economic reservoirs, and firms is considered. Methods of irreversible microeconomics are used. We show that direct sale/purchase leads to an equilibrium state which depends upon the coefficients of supply/demand functions. To reach the unique equilibrium state it is necessary to add either monetary exchange or an intermediate firm.

  4. Water Management in France: Delegation and Irreversibility

    OpenAIRE

    Ephraim Clark; Gérard Mondello

    2000-01-01

    The problem that we address in this paper stems from the trend to delegation in the water management field. It refers to the municipality’s negotiating disadvantage in the face of cartelized water management firms that makes delegation, once undertaken, virtually irreversible. We show why the characteristics of the delegation auction render is useless as a tool for collective welfare maximization. We also show that the remaining tool for achieving collective welfare maximization, i.e. the mun...

  5. Dapsone-induced pure red cell aplasia and cholestatic jaundice: A new experience for diagnosis and management.

    Science.gov (United States)

    Sawlani, Kamal Kumar; Chaudhary, Shyam Chand; Singh, Jitendra; Raja, Deep Chandh; Mishra, Sanjay; Goel, Madhu Mati

    2016-01-01

    Dapsone (4,4'- diaminodiphenylsulfone) is the parent compound of the sulfones, and it has potent antiparasitic, anti-inflammatory, and immunomodulatory effects. It is used in the treatment of leprosy, dermatitis herpetiformis, and prophylactically to prevent Pneumocystis pneumonia and toxoplasmosis in patients unable to tolerate trimethoprim with sulfamethoxazole. We hereby report a case of dapsone toxicity who developed pure red cell aplasia and cholestatic jaundice in a suspected case of dermatitis herpetiformis. Patient had an excellent response to corticosteroids after withdrawal of dapsone. PMID:27512715

  6. Extended irreversible thermodynamics revisited (1988-98)

    Science.gov (United States)

    Jou, D.; Casas-Vázquez, J.; Lebon, G.

    1999-07-01

    We review the progress made in extended irreversible thermodynamics during the ten years that have elapsed since the publication of our first review on the same subject (Rep. Prog. Phys. 1988 51 1105 - 72). During this decade much effort has been devoted to achieving a better understanding of the fundamentals and a broadening of the domain of applications. The macroscopic formulation of extended irreversible thermodynamics is reviewed and compared with other non-equilibrium thermodynamic theories. The foundations of EIT are discussed on the bases of information theory, kinetic theory, stochastic phenomena and computer simulations. Several significant applications are presented, some of them of considerable practical interest (non-classical heat transport, polymer solutions, non-Fickian diffusion, microelectronic devices, dielectric relaxation), and some others of special theoretical appeal (superfluids, nuclear collisions, cosmology). We also outline some basic problems which are not yet completely solved, such as the definitions of entropy and temperature out of equilibrium, the selection of the relevant variables, and the status to be reserved to the H-theorem and its relation to the second law. In writing this review, we had four objectives in mind: to show (i) that extended irreversible thermodynamics stands at the frontiers of modern thermodynamics; (ii) that it opens the way to new and useful applications; (iii) that much progress has been achieved during the last decade, and (iv) that the subject is far from being exhausted.

  7. Hematopoiesis stimulation test by interleukin 1α gene transfer in the Cynomolgus macaque: application to secondary medullary aplasia from an accidental irradiation

    International Nuclear Information System (INIS)

    After a description of the context of medullary aplasia (haematological radiobiology, radiation acute syndrome, therapeutic care), and an overview of knowledge about the interleukin-1 and medullary stroma cells, this research thesis aims at investigating therapeutic alternatives for radio-accidental aplasia. More precisely, it aims at defining means to get cytokines which are efficient for haematopoiesis. Interleukin-1 is chosen for its properties and tests are performed on a macaque with two approaches for gene transfer: an ex vivo transfer by retroviral vector enabling an integration in the target cell genome, and an in situ transfer by adeno-viral vector directly applied in the animal osseous medulla

  8. Linear irreversible thermodynamic performance analyses for a generalized irreversible thermal Brownian refrigerator

    Directory of Open Access Journals (Sweden)

    Zemin Ding, Lingen Chen, Yanlin Ge, Fengrui Sun

    2015-01-01

    Full Text Available On the basis of a generalized model of irreversible thermal Brownian refrigerator, the Onsager coefficients and the analytical expressions for maximum coefficient of performance (COP and the COP at maximum cooling load are derived by using the theory of linear irreversible thermodynamics (LIT. The influences of heat leakage and the heat flow via the kinetic energy change of the particles on the LIT performance of the refrigerator are analyzed. It is shown that when the two kinds of irreversible heat flows are ignored, the Brownian refrigerator is built with the condition of tight coupling between fluxes and forces and it will operate in a reversible regime with zero entropy generation. Moreover, the results obtained by using the LIT theory are compared with those obtained by using the theory of finite time thermodynamics (FTT. It is found that connection between the LIT and FTT performances of the refrigerator can be interpreted by the coupling strength, and the theory of LIT and FTT can be used in a complementary way to analyze in detail the performance of the irreversible thermal Brownian refrigerators. Due to the consideration of several irreversibilities in the model, the results obtained about the Brownian refrigerator are of general significance and can be used to analyze the performance of several different kinds of Brownian refrigerators.

  9. An action principle of classical irreversible thermodynamics - Irreversible thermodynamic cycles and embodied bits of information

    CERN Document Server

    Hanel, Rudolf A

    2016-01-01

    Despite its simplicity, it seems to my best of knowledge that the possibly simplest approach towards deriving equations governing irreversible thermodynamics from gas-kinetic considerations within the framework of classical mechanics has never been pursued. In this paper we address this omission and derive the equations describing the irreversible thermodynamics of a gas in a piston and associated thermodynamic cycles performed in finite time. What we find is a thermodynamic action principle: The irreversible work we require for performing a thermodynamic cycle in finite time times the time we require to run through the cycle, a isothermal compression/decompression cycle for instance, will always be larger or equal to a lower bound given by a system specific constant with the dimension of an action. This process specific action constants can take values of the order of Plank's constant for microscopic processes, such as displacing a Hydrogen atom by one atom diameter. For macroscopic processes (e.g. a bicycle...

  10. Thermodynamics of irreversible plant cell growth

    Directory of Open Access Journals (Sweden)

    Mariusz Pietruszka

    2011-04-01

    Full Text Available The time-irreversible cell enlargement of plant cells at a constant temperature results from two independent physical processes, e.g. water absorption and cell wall yielding. In such a model cell growth starts with reduction in wall stress because of irreversible extension of the wall. The water absorption and physical expansion are spontaneous consequences of this initial modification of the cell wall (the juvenile cell vacuolate, takes up water and expands. In this model the irreversible aspect of growth arises from the extension of the cell wall. Such theory expressed quantitatively by time-dependent growth equation was elaborated by Lockhart in the 60's.The growth equation omit however a very important factor, namely the environmental temperature at which the plant cells grow. In this paper we put forward a simple phenomenological model which introduces into the growth equation the notion of temperature. Moreover, we introduce into the modified growth equation the possible influence of external growth stimulator or inhibitor (phytohormones or abiotic factors. In the presence of such external perturbations two possible theoretical solutions have been found: the linear reaction to the application of growth hormones/abiotic factors and the non-linear one. Both solutions reflect and predict two different experimental conditions, respectively (growth at constant or increasing concentration of stimulator/inhibitor. The non-linear solution reflects a common situation interesting from an environmental pollution point of view e.g. the influence of increasing (with time concentration of toxins on plant growth. Having obtained temperature modified growth equations we can draw further qualitative and, especially, quantitative conclusions about the mechanical properties of the cell wall itself. This also concerns a new and interesting result obtained in our model: We have calculated the magnitude of the cell wall yielding coefficient (T [m3 J-1•s-1] in

  11. Magnetic Irreversibility in VO2/Ni Bilayers

    Science.gov (United States)

    de La Venta, Jose; Lauzier, Josh; Sutton, Logan

    The temperature dependence of the coercivity and magnetization of VO2/Ni bilayers was studied. VO2 exhibits a well-known Structural Phase Transition (SPT) at 330-340 K, from a low temperature monoclinic (M) to a high temperature rutile (R) structure. The SPT of VO2 induces an inverse magnetoelastic effect that strongly modifies the coercivity and magnetization of the Ni films. In addition, the growth conditions allow tuning of the magnetic properties. Ni films deposited on top of VO2 (M) show an irreversible change in the coercivity after the first cycle through the high temperature phase, with a corresponding change in the surface morphology of VO2. On the other hand, the Ni films grown on top of VO2 (R) do not show this irreversibility. These results indicate that properties of magnetic films are strongly affected by the strain induced by materials that undergo SPT and that it is possible to control the magnetic properties by tuning the growth conditions.

  12. Irreversible electroporation: state of the art

    Directory of Open Access Journals (Sweden)

    Wagstaff PGK

    2016-04-01

    Full Text Available Peter GK Wagstaff,1 Mara Buijs,1 Willemien van den Bos,1 Daniel M de Bruin,2 Patricia J Zondervan,1 Jean JMCH de la Rosette,1 M Pilar Laguna Pes1 1Department of Urology, 2Department of Biomedical Engineering and Physics, Academic Medical Center, Amsterdam, the Netherlands Abstract: The field of focal ablative therapy for the treatment of cancer is characterized by abundance of thermal ablative techniques that provide a minimally invasive treatment option in selected tumors. However, the unselective destruction inflicted by thermal ablation modalities can result in damage to vital structures in the vicinity of the tumor. Furthermore, the efficacy of thermal ablation intensity can be impaired due to thermal sink caused by large blood vessels in the proximity of the tumor. Irreversible electroporation (IRE is a novel ablation modality based on the principle of electroporation or electropermeabilization, in which electric pulses are used to create nanoscale defects in the cell membrane. In theory, IRE has the potential of overcoming the aforementioned limitations of thermal ablation techniques. This review provides a description of the principle of IRE, combined with an overview of in vivo research performed to date in the liver, pancreas, kidney, and prostate. Keywords: irreversible electroporation, IRE, tumor, ablation, focal therapy, cancer

  13. The Value of Fighting Irreversible Demise by Softening the Irreversible Cost

    NARCIS (Netherlands)

    Magis, P.; Sbuelz, A.

    2005-01-01

    We study a novel issue in the real-options-based technology innovation literature by means of double barrier contingent claims analysis.We show how much a ¯rm with the monopoly over a project is willing to spend in investment technology innovation that softens the irreversible cost of accessing the

  14. Bacterial, fungal and yeast contamination in six brands of irreversible hydrocolloid impression materials Contaminação por bactérias, fungos e leveduras em seis marcas comerciais de materiais de moldagem à base de hidrocolóide irreversível

    Directory of Open Access Journals (Sweden)

    Luciana Assirati Casemiro

    2007-06-01

    Full Text Available This study assessed the level of contamination of six commercially available irreversible hydrocolloids (two containing chlorhexidine and identified the contamination present in the materials. Petri dishes containing selective and enriched culture media were inoculated with alginate powder (0.06 g, in triplicate. After incubation (37°C/7 days, the colony-forming units (CFU were counted and Gram stained. Biochemical identification of the different morphotypes was also performed. The contamination levels for the materials were: Jeltrate - 389 CFU/g; Jeltrate Plus - 516 CFU/g; Jeltrate Chromatic - 135 CFU/g; Hydrogum - 1,455 CFU/g; Kromopan - 840 CFU/g; and Greengel - 59 CFU/g. Gram staining revealed the presence of Gram-positive bacillus and Gram-positive cocci. The bacteria Staphylococcus epidermidis, Bacillus subtilis, Bacillus sp., Bacillus coagulans, Bacillus licheniformis, Bacillus cereus, Micrococcus luteus, and Nocardia sp.; the filamentous fungi Aspergillus niger, Aspergillus flavus, Rhizopus sp., Neurospora sp.; and the yeast Candida sp. were isolated. The contamination detected in the impression materials points out the need for adopting measures to improve the microbiological quality of these materials. The use of contaminated materials in the oral cavity goes against the basic principles for controlling cross-contamination and may represent a risk for debilitated or immunocompromised patients.Este estudo avaliou o nível de contaminação de seis marcas comerciais de alginato (duas contendo clorexidina e identificou a contaminação presente nesses materiais. Alíquotas de alginato (0,06 g foram semeadas em meios de cultura seletivos e enriquecidos, em triplicata. Após incubação (37°C/7 dias, as unidades formadoras de colônia (UFC foram contadas e foram realizadas as identificações morfotintorial (Gram e bioquímica. Os níveis de contaminação dos materiais foram: Jeltrate - 389 UFC/g; Jeltrate Plus - 516 UFC/g; Jeltrate

  15. Entropy, Extropy and the Physical Driver of Irreversibility

    Directory of Open Access Journals (Sweden)

    Attila Grandpierre

    2012-06-01

    Full Text Available We point out that the fundamental irreversibility of Nature requires the introduction of a suitable measure for the distance from equilibrium. We show that entropy, which is widely held to be such a measure, suffers from the problem that it does not have a physical meaning, since it is introduced on the basis of mathematical arguments. As a consequence, the basic physics beyond irreversibility has remained obscure. We present here a simple but transparent physical approach for solving the problem of irreversibility. This approach shows that extropy, the fundamental thermodynamic variable introduced by Katalin Martinás, is the suitable measure for the distance from equilibrium, since it corresponds to the actual driver of irreversible processes. Since extropy explicitly contains in its definition all the general thermodynamic forces that drive irreversible processes, extropy is the suitable physical measure of irreversibility.

  16. Time evolution of an irreversible recombination process

    International Nuclear Information System (INIS)

    The time evolution of the irreversible catalytic recombination process, A + B → inert is studied both analytically as well as by computer simulation. A rate equation describing this process is derived. For situations where one of the species poisons the catalyst, the minority species, under certain conditions, is found to decay exponentially. Computer simulation results also indicate exponential decay for intermediate times. Near the poisoning transition, xA ≅ xB, the average relaxation time is found to diverge as τ ∼ (1)/(0.5-xA)γ with γ ≅ 1.3. Here xA and xB are the compositions of A and B in the gas. (author). 6 refs, 4 figs

  17. Steady reactive state in an irreversible reaction

    International Nuclear Information System (INIS)

    A simple two component irreversible surface reaction model introduced by Ziff, Gulari and Bershad to study the reaction of carbon monoxide with oxygen has been investigated in detail by monte carlo simulation technique. The Model predicts a first order phase transition at a carbon monoxide feed concentration (Y=0.399) and a second order phase transition at (Y=0.5255). It is found that both the coverage of carbon monoxide and oxygen as well as the production of carbon dioxide with in the window described by the two critical points follows either a linear or an exponential behavior as a function of the concentration. The behavior of these quantities near the critical points is however more complicated. (author)

  18. Work Criteria Function of Irreversible Heat Engines

    Directory of Open Access Journals (Sweden)

    Mahmoud Huleihil

    2014-01-01

    Full Text Available The irreversible heat engine is reconsidered with a general heat transfer law. Three criteria known in the literature—power, power density, and efficient power—are redefined in terms of the work criteria function (WCF, a concept introduced in this study. The formulation enabled the suggestion and analysis of a unique criterion—the efficient power density (which accounts for the efficiency and power density. Practically speaking, the efficient power and the efficient power density could be defined on any order based on the WCF. The applicability of the WCF is illustrated for the Newtonian heat transfer law (n=1 and for the radiative law (n=4. The importance of WCF is twofold: it gives an explicit design and educational tool to analyze and to display graphically the different criteria side by side and thus helps in design process. Finally, the criteria were compared and some conclusions were drawn.

  19. Diffusion of irreversible energy technologies under uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Cacallo, J.D.; Sutherland, R.J.

    1993-09-01

    This paper presents a model of technology diffusion is consistent with characteristics of participants in most energy markets. Whereas the models used most widely for empirical research are based on the assumption that the extended delays in adoption of cost-saving innovations are the result of either lack of knowledge about the new processes or heterogeneity across potential adopters, the model presented in this paper is based on the strategic behavior by firms. The strategic interdependence of the firms` decisions is rooted in spillover effects associated with an inability to exclude others from the learning-by-doing acquired when a firm implements a new technology. The model makes extensive use of recent developments in investment theory as it relates irreversible investments under uncertainty.

  20. Exergetic sustainability evaluation of irreversible Carnot refrigerator

    Science.gov (United States)

    Açıkkalp, Emin

    2015-10-01

    Purpose of this paper is to assess irreversible refrigeration cycle by using exergetic sustainability index. In literature, there is no application of exergetic sustainability index for the refrigerators and, indeed, this index has not been derived for refrigerators. In this study, exergetic sustainability indicator is presented for the refrigeration cycle and its relationships with other thermodynamics parameters including COP, exergy efficiency, cooling load, exergy destruction, ecological function and work input are investigated. Calculations are conducted for endoreversible and reversible cycles and then results obtained from the ecological function are compared. It is found that exergy efficiency, exergetic sustainable index reduce 47.595% and 59.689% and rising at the COP is 99.888% is obtained for endoreversible cycle. Similarly, exergy efficiency and exergetic sustainability index reduce 90.163% and 93.711% and rising of the COP is equal to 99.362%.

  1. Synergetcs - a field beyond irreversible thermodynamics

    International Nuclear Information System (INIS)

    This lecture introduces the reader to synergetics, a very young field of interdisciplinary research, which is devoted to the question of self-organization and, quite generally, to the birth of new qualities. After comparing the role of thermodynamics, irreversible thermodynamics and synergetics in the description of phenomena we give a few examples for self-oragnizing systems. Next we outline the mathematical approach and consider the generalized Ginzburg-Landau equations for non equilibrium phase transitions. We continue by applying these equations to the problem of morphogenesis in biology. We close our lecture by extending the formalism to spatially inhomogeneous or oscillating systems and arrive at order-parameter equations which are capable of describing new large classes of higher bifurcation schemes. (HJ)

  2. Chemical kinetics, stochastic processes, and irreversible thermodynamics

    CERN Document Server

    Santillán, Moisés

    2014-01-01

    This book brings theories in nonlinear dynamics, stochastic processes, irreversible thermodynamics, physical chemistry, and biochemistry together in an introductory but formal and comprehensive manner.  Coupled with examples, the theories are developed stepwise, starting with the simplest concepts and building upon them into a more general framework.  Furthermore, each new mathematical derivation is immediately applied to one or more biological systems.  The last chapters focus on applying mathematical and physical techniques to study systems such as: gene regulatory networks and ion channels. The target audience of this book are mainly final year undergraduate and graduate students with a solid mathematical background (physicists, mathematicians, and engineers), as well as with basic notions of biochemistry and cellular biology.  This book can also be useful to students with a biological background who are interested in mathematical modeling, and have a working knowledge of calculus, differential equatio...

  3. Irreversible electroporation: state of the art.

    Science.gov (United States)

    Wagstaff, Peter Gk; Buijs, Mara; van den Bos, Willemien; de Bruin, Daniel M; Zondervan, Patricia J; de la Rosette, Jean Jmch; Laguna Pes, M Pilar

    2016-01-01

    The field of focal ablative therapy for the treatment of cancer is characterized by abundance of thermal ablative techniques that provide a minimally invasive treatment option in selected tumors. However, the unselective destruction inflicted by thermal ablation modalities can result in damage to vital structures in the vicinity of the tumor. Furthermore, the efficacy of thermal ablation intensity can be impaired due to thermal sink caused by large blood vessels in the proximity of the tumor. Irreversible electroporation (IRE) is a novel ablation modality based on the principle of electroporation or electropermeabilization, in which electric pulses are used to create nanoscale defects in the cell membrane. In theory, IRE has the potential of overcoming the aforementioned limitations of thermal ablation techniques. This review provides a description of the principle of IRE, combined with an overview of in vivo research performed to date in the liver, pancreas, kidney, and prostate. PMID:27217767

  4. Irreversible Electroporation (IRE) in Renal Tumors.

    Science.gov (United States)

    Narayanan, Govindarajan; Doshi, Mehul H

    2016-02-01

    Small renal masses (SRMs) have been traditionally managed with surgical resection. Minimally invasive nephron-sparing treatment methods are preferred to avoid harmful consequences of renal insufficiency, with partial nephrectomy (PN) considered the gold standard. With increase in the incidence of the SRMs and evolution of ablative technologies, percutaneous ablation is now considered a viable treatment alternative to surgical resection with comparable oncologic outcomes and better nephron-sparing property. Traditional thermal ablative techniques suffer from unique set of challenges in treating tumors near vessels or critical structures. Irreversible electroporation (IRE), with its non-thermal nature and connective tissue-sparing properties, has shown utility where traditional ablative techniques face challenges. This review presents the role of IRE in renal tumors based on the most relevant published literature on the IRE technology, animal studies, and human experience. PMID:26769468

  5. Treatment with misonidazole and high voltage irradiation of xenotransplanted human carcinomas in nu/nu mice with thymic aplasia

    International Nuclear Information System (INIS)

    An investigation was conducted in order to determine the effect of combined high voltage irradiation and the sensitizing drug misonidazole (Ro-07-0582) on human gynecologic carcinoma transplanted into nu/nu mice with thymic aplasia. Two carcinomas of the endometrium, two carcinomas of the ovaries, and one carcinoma of the cervix were submitted to Co-60 irradiation with and without misonidazole. The tumor growth was compared to that of control groups. The dosage and fraction of the high voltage irradiation (2 x 5 Gy/week, total dose 60 Gy) were adapted to clinical data. Misonidazole (1 mg/kg body weight) was administered by intraperitoneal injection 15 minutes before the irradiation. Compared with the control animals, the locally irradiated tumors showed a slower growth or even a regression. The administration of misonidazole, however, did not produce significant differences in our five cases. Some reasons for this absence of the radiosensitizing effect of misonidazole are briefly discussed. (orig.)

  6. Aplasia medular após transplante hepático em pediatria Aplastic anemia after pediatric liver transplantation

    Directory of Open Access Journals (Sweden)

    Marlene P. Garanito

    2009-01-01

    Full Text Available A aplasia de medula é uma das mais raras (Aplastic anemia (AA is one of the rarest (<1% and most serious complications of liver transplantation for fulminant non-A, non-B and non-C hepatitis. It was first described in 1987 by Stock; the mechanism involved is an immunologically mediated condition secondary to an unknown viral infection. The disease is associated with a dismal prognosis. Spontaneous recovery from acquired AA is very rare however some patients (50-70% recover after immunosuppressive therapy, such as Cyclosporin A (CsA and Antithymocyte globulin (ATG, even after liver transplantation. Another treatment option is bone marrow transplantation. We report on a child who developed AA following liver transplantation for fulminant viral hepatitis that was treated with intensive immunosuppression including CsA and ATG and achieved complete recovery.

  7. Investment Irreversibility and Precautionary Savings in General Equilibrium

    DEFF Research Database (Denmark)

    Ejarque, João

    Partial equilibrium models suggest that when uncertainty increases, agents increase savings and at the same time reduce investment in irreversible goods. This paper characterizes this problem in general equilibrium with technology shocks, additive output shocks and shocks to the marginal efficiency...... of investment. Uncertainty is associated with the variance of these random variables, and irreversibility is introduced by a non negativity constraint on investment. I find that irreversibility and changes in uncertainty can be responsible for sizeable movements in aggregate consumption and...

  8. Performance of an irreversible quantum Carnot engine with spin 12.

    Science.gov (United States)

    Wu, Feng; Chen, Lingen; Wu, Shuang; Sun, Fengrui; Wu, Chih

    2006-06-01

    The purpose of this paper is to investigate the effect of quantum properties of the working medium on the performance of an irreversible Carnot cycle with spin 12. The optimal relationship between the dimensionless power output P* versus the efficiency eta for the irreversible quantum Carnot engine with heat leakage and other irreversible losses is derived. Especially, the performances of the engine at low temperature limit and at high temperature limit are discussed. PMID:16774426

  9. A rare presentation of aplasia cutis congenita after feto-reduction in a trichorionic-triamniotic pregnancy.

    Science.gov (United States)

    Vettori, D J; Jairath, P

    2015-01-01

    Aplasia cutis congenita (ACC) is rare skin disorder of newborns that has been linked to both assisted reproductive technology (ART) and feto-reduction procedures. ACC is characterized by well-demarcated lesions that are devoid of all skin layers. Group-V ACC presents with a distinctive and symmetrical distribution pattern. It is thought to result from an insult to the fetus after concomitant twin demise and is almost exclusively reported in monochorionic gestations.A 41-year-old female with an in vitro fertilization (IVF) assisted tri-chorionic gestation subsequently underwent selective feto-reduction of Fetus C. The patient delivered two pre-term neonates secondary to pre-eclampsia. The initial exam of Twin B showed extensive, well-demarcated, symmetrical areas devoid of any skin over the anterior and lateral trunk, extending up the lateral thoracic walls. Chest and abdominal viscera were visible through a thin fibrous membrane. The skin defects were managed conservatively with twice-daily dressings of Aquaphor, and Vaseline gauze. The areas of aplasia slowly contracted, though residual scarring was noted. After four weeks in the NICU, most of the areas were healed.ACC in multi-fetal pregnancies is a rare, but well-described complication. This is, to our knowledge, the first reported case in a tri-chorionic IVF gestation after feto-reduction. With increased incidence of ART-associated pregnancies and the use of feto-reduction for higher order gestations, this may become more common. Neonates often require specialized intensive care. Conservative management usually will suffice, although surgical grafting may be required. Physicians should be aware of this condition and counsel their feto-reduction patients of the risk. PMID:26485557

  10. Therapeutic potential of ex vivo expansion of haematopoietic precursors for the treatment of accidental irradiation-induced aplasia

    International Nuclear Information System (INIS)

    After whole body overexposure, the key issue is the therapeutic decision, i.e. the choice between bone marrow transplantation and other strategies. The indications of bone marrow transplantation cover only a short range of doses, provided the exposure is distributed uniformly within the body; a rare event in accidental settings. The results of the clinical trials for Granulocyte-Colony Stimulating Factor: G-CSF, Granulocyte/Macrophage Colony Stimulating Factor: GM-CSF or Interleukin 3: IL-3, in vivo and in vitro radiobiology experiments suggest that growth factor therapy could be of use after most accidental overexposures to evidence and to stimulate the remaining haematopoietic stem cells in order to shorten the duration of aplasia, although questions have been raised about growth factor infusion real clinical efficiency. Ex vivo expansion of haematopoietic precursor, stem cells and differentiated cells is a new approach of growth factor therapy, which may be of interest for the treatment of patients with accidental radiation-induced aplasia. These studies aim to expand the pool of progenitors and stem cells for transplantation or to expand differentiated cells (mainly granulocytes but also megakaryocytes) for transfusion. This is made possible due to the development of techniques allowing the selection of a population of haematopoietic progenitors and stem cells from the blood (with stimulation by growth factors prior stem cell harvesting) or bone marrow using immature cell positive selection. The next step consisting in their culture with combination of growth factors or additional stroma cells is also under development. Autologous progenitor cells generated ex vivo has been recently used with some success for reconstitution of haematopoiesis after high-dose chemotherapy. (author)

  11. Irreversible magnetic processes under biaxial and uniaxial magnetic anisotropies

    Science.gov (United States)

    Pokharel, S.; Akioya, O.; Alqhtany, N. H.; Dickens, C.; Morgan, W.; Wuttig, M.; Lisfi, A.

    2016-05-01

    Irreversible magnetic processes have been investigated in magnetic systems with two different anisotropy symmetries (uniaxial and biaxial) through angular measurement of the switching field, the irreversible susceptibility and the magnetic viscosity. These two systems consist of two-dimensional cobalt ferrite hetero-structures epitaxially grown on (100) and (110) MgO substrate. It is found that for uniaxial anisotropy the irreversible characteristics of the magnetization are large and display a strong angular dependence, which exhibits its maximum at the easy axis and drops quickly to vanish at the hard axis. However, for biaxial anisotropy the magnetization irreversible characteristics are considerably reduced and are less sensitive to the field angle.

  12. Guinea pig ductus arteriosus. II - Irreversible closure after birth.

    Science.gov (United States)

    Fay, F. S.; Cooke, P. H.

    1972-01-01

    To investigate the mechanism underlying irreversibility of ductal closure after birth, studies were undertaken to determine the exact time course for the onset of irreversible closure of the guinea pig ductus arteriosus. Parallel studies of the reactivity of ductal smooth muscle to oxygen and studies of the postpartum cellular changes within the vessel were also carried out.

  13. Combustion irreversibilities: Numerical simulation and analysis

    Science.gov (United States)

    Silva, Valter; Rouboa, Abel

    2012-08-01

    An exergy analysis was performed considering the combustion of methane and agro-industrial residues produced in Portugal (forest residues and vines pruning). Regarding that the irreversibilities of a thermodynamic process are path dependent, the combustion process was considering as resulting from different hypothetical paths each one characterized by four main sub-processes: reactant mixing, fuel oxidation, internal thermal energy exchange (heat transfer), and product mixing. The exergetic efficiency was computed using a zero dimensional model developed by using a Visual Basic home code. It was concluded that the exergy losses were mainly due to the internal thermal energy exchange sub-process. The exergy losses from this sub-process are higher when the reactants are preheated up to the ignition temperature without previous fuel oxidation. On the other hand, the global exergy destruction can be minored increasing the pressure, the reactants temperature and the oxygen content on the oxidant stream. This methodology allows the identification of the phenomena and processes that have larger exergy losses, the understanding of why these losses occur and how the exergy changes with the parameters associated to each system which is crucial to implement the syngas combustion from biomass products as a competitive technology.

  14. Irreversible Electroporation for Colorectal Liver Metastases.

    Science.gov (United States)

    Scheffer, Hester J; Melenhorst, Marleen C A M; Echenique, Ana M; Nielsen, Karin; van Tilborg, Aukje A J M; van den Bos, Willemien; Vroomen, Laurien G P H; van den Tol, Petrousjka M P; Meijerink, Martijn R

    2015-09-01

    Image-guided tumor ablation techniques have significantly broadened the treatment possibilities for primary and secondary hepatic malignancies. A new ablation technique, irreversible electroporation (IRE), was recently added to the treatment armamentarium. As opposed to thermal ablation, cell death with IRE is primarily induced using electrical energy: electrical pulses disrupt the cellular membrane integrity, resulting in cell death while sparing the extracellular matrix of sensitive structures such as the bile ducts, blood vessels, and bowel wall. The preservation of these structures makes IRE attractive for colorectal liver metastases (CRLM) that are unsuitable for resection and thermal ablation owing to their anatomical location. This review discusses different technical and practical issues of IRE for CRLM: the indications, patient preparations, procedural steps, and different "tricks of the trade" used to improve safety and efficacy of IRE. Imaging characteristics and early efficacy results are presented. Much is still unknown about the exact mechanism of cell death and about factors playing a crucial role in the extent of cell death. At this time, IRE for CRLM should only be reserved for small tumors that are truly unsuitable for resection or thermal ablation because of abutment of the portal triad or the venous pedicles. PMID:26365546

  15. Irreversible properties of YBCO coated conductors

    CERN Document Server

    Vostner, A

    2001-01-01

    dependence of the irreversibility fields up to 6 T. To gain more insight into the defect structure of the films, neutron irradiation studies were performed on some samples. The introduction of these artificial pinning centers causes large enhancements of the magnetic J sub c in LPE specimens for the field parallel to the c-axis (H//c) at higher temperatures and magnetic fields. The granular structure of the samples does not change up to the highest neutron fluences. However, the enhancements of the transport J sub c 's are not as pronounced as observed in the magnetic measurements. The optimum defect cascade density is determined by sequential irradiation. Especially at higher fluences, the damage caused by the irradiation dominates over the additional pinning force and results in a reduction of the transport J sub c 's. This effect is even more pronounced for fields perpendicular to the c-axis (H//ab). A comparison of irradiation studies between samples deposited by LPE and by PLD shows that LPE films have a...

  16. Irreversible energy flow in forced Vlasov dynamics

    KAUST Repository

    Plunk, Gabriel G.

    2014-10-01

    © EDP Sciences, Società Italiana di Fisica, Springer-Verlag. The recent paper of Plunk [G.G. Plunk, Phys. Plasmas 20, 032304 (2013)] considered the forced linear Vlasov equation as a model for the quasi-steady state of a single stable plasma wavenumber interacting with a bath of turbulent fluctuations. This approach gives some insight into possible energy flows without solving for nonlinear dynamics. The central result of the present work is that the forced linear Vlasov equation exhibits asymptotically zero (irreversible) dissipation to all orders under a detuning of the forcing frequency and the characteristic frequency associated with particle streaming. We first prove this by direct calculation, tracking energy flow in terms of certain exact conservation laws of the linear (collisionless) Vlasov equation. Then we analyze the steady-state solutions in detail using a weakly collisional Hermite-moment formulation, and compare with numerical solution. This leads to a detailed description of the Hermite energy spectrum, and a proof of no dissipation at all orders, complementing the collisionless Vlasov result.

  17. Irreversible work in a thermal medium with colored noise

    International Nuclear Information System (INIS)

    Irreversible work and its fluctuations in a classical system governed by non-Markovian stochastic dynamics are investigated. The production of irreversible work depends not only on the protocol of an operation but also on the details of the non-Markovian memory. We consider a generalized Langevin equation with a memory kernel and derive an expression for the irreversible work in the case of slow operations by carrying out an expansion of this memory kernel in the parameter representing the length of the memory. We apply our formulation to a harmonically trapped system and demonstrate the efficiency of a cycle by evaluating the irreversible work. It is found that a decrease in the irreversible work due to the memory effect can occur for an operation through which the trap is squeezed. The results for this harmonic system are verified exactly in the case that the memory kernel has exponential decay

  18. Irreversible Electroporation in a Swine Lung Model

    International Nuclear Information System (INIS)

    Purpose: This study was designed to evaluate the safety and tissue effects of IRE in a swine lung model. Methods: This study was approved by the institutional animal care committee. Nine anesthetized domestic swine underwent 15 percutaneous irreversible electroporation (IRE) lesion creations (6 with bipolar and 3 with 3–4 monopolar electrodes) under fluoroscopic guidance and with pancuronium neuromuscular blockade and EKG gating. IRE electrodes were placed into the central and middle third of the right mid and lower lobes in all animals. Postprocedure PA and lateral chest radiographs were obtained to evaluate for pneumothorax. Three animals were sacrificed at 2 weeks and six at 4 weeks. Animals underwent high-resolution CT scanning and PA and lateral radiographs 1 h before sacrifice. The treated lungs were removed en bloc, perfused with formalin, and sectioned. Gross pathologic and microscopic changes after standard hematoxylin and eosin staining were analyzed within the areas of IRE lesion creation. Results: No significant adverse events were identified. CT showed focal areas of spiculated high density ranging in greatest diameter from 1.1–2.2 cm. On gross inspection of the sectioned lung, focal areas of tan discoloration and increased density were palpated in the areas of IRE. Histological analysis revealed focal areas of diffuse alveolar damage with fibrosis and inflammatory infiltration that respected the boundaries of the interlobular septae. No pathological difference could be discerned between the 2- and 4-week time points. The bronchioles and blood vessels within the areas of IRE were intact and did not show signs of tissue injury. Conclusion: IRE creates focal areas of diffuse alveolar damage without creating damage to the bronchioles or blood vessels. Short-term safety in a swine model appears to be satisfactory.

  19. CD19 CAR-targeted T cells induce long-term remission and B Cell Aplasia in an immunocompetent mouse model of B cell acute lymphoblastic leukemia.

    Directory of Open Access Journals (Sweden)

    Marco L Davila

    Full Text Available Although many adults with B cell acute lymphoblastic leukemia (B-ALL are induced into remission, most will relapse, underscoring the dire need for novel therapies for this disease. We developed murine CD19-specific chimeric antigen receptors (CARs and an immunocompetent mouse model of B-ALL that recapitulates the disease at genetic, cellular, and pathologic levels. Mouse T cells transduced with an all-murine CD3ζ/CD28-based CAR that is equivalent to the one being used in our clinical trials, eradicate B-ALL in mice and mediate long-term B cell aplasias. In this model, we find that increasing conditioning chemotherapy increases tumor eradication, B cell aplasia, and CAR-modified T cell persistence. Quantification of recipient B lineage cells allowed us to estimate an in vivo effector to endogenous target ratio for B cell aplasia maintenance. In mice exhibiting a dramatic B cell reduction we identified a small population of progenitor B cells in the bone marrow that may serve as a reservoir for long-term CAR-modified T cell stimulation. Lastly, we determine that infusion of CD8+ CAR-modified T cells alone is sufficient to maintain long-term B cell eradication. The mouse model we report here should prove valuable for investigating CAR-based and other therapies for adult B-ALL.

  20. Irreversible Sorption of Contaminants During Ferrihydrite Transformation

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, H.L.; Arthur, S.E.; Brady, P.V.; Cygan, R.T.; Nagy, K.L.; Westrich, H.R.

    1999-05-19

    A better understanding of the fraction of contaminants irreversibly sorbed by minerals is necessary to effectively quantify bioavailability. Ferrihydrite, a poorly crystalline iron oxide, is a natural sink for sorbed contaminants. Contaminants may be sorbed/occluded as ferrihydrite precipitates in natural waters or as it ages and transforms to more crystalline iron oxides such as goethite or hematite. Laboratory studies indicate that Cd, Co, Cr, Cu, Ni, Np, Pb, Sr, U, and Zn are irreversibly sorbed to some extent during the aging and transformation of synthetic ferrihydrite. Barium, Ra and Sr are known to sorb on ferrihydrite in the pH range of 6 to 10 and sorb more strongly at pH values above its zero point of charge (pH> 8). We will review recent literature on metal retardation, including our laboratory and modeling investigation of Ba (as an analogue for Ra) and Sr adsorption/resorption, during ferrihydrite transformation to more crystalline iron oxides. Four ferrihydrite suspensions were aged at pH 12 and 50 °C with or without Ba in 0.01 M KN03 for 68 h or in 0.17 M KN03 for 3424 h. Two ferrihydrite suspensions were aged with and without Sr at pH 8 in 0.1 M KN03 at 70°C. Barium or Sr sorption, or resorption, was measured by periodically centrifuging suspension subsamples, filtering, and analyzing the filtrate for Ba or Sr. Solid subsamples were extracted with 0.2 M ammonium oxalate (pH 3 in the dark) and with 6 M HCl to determine the Fe and Ba or Sr attributed to ferrihydrite (or adsorbed on the goethite/hematite stiace) and the total Fe and Ba or Sr content, respectively. Barium or Sr occluded in goethite/hematite was determined by the difference between the total Ba or Sr and the oxalate extractable Ba or Sr. The percent transformation of ferrihydrite to goethite/hematite was estimated from the ratio of oxalate and HC1 extractable Fe. All Ba was retained in the precipitates for at least 20 h. Resorption of Ba reached a maximum of 7 to 8% of the Ba2+ added

  1. Infecção por Chryseobacterium indologenes: relato de um caso Chryseobacterium indologenes infection: a case report

    OpenAIRE

    Renata de Souza Ferreira; Fabiana Ferreira Barbosa Brandão; Suzana Margareth Lobo

    2010-01-01

    Relatamos um caso de infecção por Chryseobacterium indologenes, presente na cultura de aspirado traqueal em paciente sob ventilação mecânica invasiva, revisando os aspectos epidemiológicos, microbiológicos e o tratamento na unidade de terapia intensiva. Paciente do sexo masculino, 30 anos, internado com quadro de aplasia de medula idiopática e neutropenia febril foi transferido para a unidade de terapia intensiva com quadro de broncopneumonia e sepse grave de origem pulmonar. A maioria dos ca...

  2. Clinical importance of digitized chest X-ray for detection of pulmonary infiltrations in bone marrow transplant patients during aplasia

    International Nuclear Information System (INIS)

    Purpose: Evaluation of digitized chest X-ray for the detection of pulmonary infiltrations in bone marrow transplant patients during aplasia. Methods: Digitized chest X-rays of 40 patients (21 female, 19 male) with 'Fever of unknown origin' (FUO) were evaluated concerning radiological signs of pulmonary infiltrations and correlated to clinical findings, blood chemistry, microbiology and bronchoscopy. Additionally, an individual risk profile was established. Results: In 11/40 patients pulmonary infiltrations were detected in digitized chest X-rays (group 1). 10/11 developed an infectious pulmonary infiltration. 29/40 patients developed no pulmonary infiltration (group 2). When fever increased for the first time (initial chest X-ray) a sensitivity, specificity, positive and negative predictive value of 46%, 86%, 56%, 81% and for the chest X-rays in process of 61%, 79%, 68% and 73% was found. C-reactive protein and temperature increase occured statistically significantly earlier (p<0.05) in group 1 compared to group 2. The average latency of digital chest X-rays in comparison to c-reactive protein and temperature increase was 6 days. The incidence of risk factors was significantly higher in group 1 in comparison to group 2 (p<0.05). Conclusion: Digitized chest X-rays are not a reliable method for primary detection of pulmonary infiltrations after bone marrow transplantation. Individual risk factors have to be taken into consideration to indicate further diagnostic methods such as computed tomography at an earlier time. (orig.)

  3. [Changes in bones of the foot and development of inserting tendons of the lower leg musculature in tibial aplasia].

    Science.gov (United States)

    Selke, B; Bogusch, G

    1989-01-01

    Skeleton, muscles and tendons were investigated in 3 lower legs with aplasia of the tibia. The tibiofibular joint appears to be rather a syndesmosis than a diarthrosis. In all 3 cases, talus and calcaneus are connected by a synostosis. Also in the other parts of the skeleton of the feet, synarthroses with different extensions are found. The muscles, normally originating from the tibia, have shifted their origin to the fibula. The proximal part of the inserting tendons under the retinacula is quite normal. Also, their distal part in the region of the metatarsalia and of the digits exhibits no alterations. In the region of the tarsus in which already alterations in bone formation are found, the tendons of the flexor muscles of the toes exhibit some variations. Often the muscles show a new, strong insertion into the bones of the tarsus. The normal connection between the proximal and distal parts of the tendons is sometimes still indicated by a thin bundle of collagenous fibers. In all 3 cases, the tibialis anterior muscle inserts into the distal part of the tendons of the flexor muscles of the toes, indicating that there are also connections between tendons of muscles from different blastemas. PMID:2816255

  4. Kinetic theory of nonequilibrium ensembles, irreversible thermodynamics, and generalized hydrodynamics

    CERN Document Server

    Eu, Byung Chan

    2016-01-01

    This book presents the fundamentals of irreversible thermodynamics for nonlinear transport processes in gases and liquids, as well as for generalized hydrodynamics extending the classical hydrodynamics of Navier, Stokes, Fourier, and Fick. Together with its companion volume on relativistic theories, it provides a comprehensive picture of the kinetic theory formulated from the viewpoint of nonequilibrium ensembles in both nonrelativistic and, in Vol. 2, relativistic contexts. Theories of macroscopic irreversible processes must strictly conform to the thermodynamic laws at every step and in all approximations that enter their derivation from the mechanical principles. Upholding this as the inviolable tenet, the author develops theories of irreversible transport processes in fluids (gases or liquids) on the basis of irreversible kinetic equations satisfying the H theorem. They apply regardless of whether the processes are near to or far removed from equilibrium, or whether they are linear or nonlinear with respe...

  5. Ecolosical optimization of an irreversible harmonic oscillators Carnot heat engine

    Institute of Scientific and Technical Information of China (English)

    LIU XiaoWei; CHEN LinGen; WU Feng; SUN FengRui

    2009-01-01

    A model of an irreversible quantum Carnot heat engine with heat resistance, internal irreversibility and heat leakage and many non-interacting harmonic oscillators is established in this paper. Based on the quantum master equation and semi-group approach, equations of some important performance parameters, such as power output, efficiency, exergy loss rate and ecological function for the irreversible quantum Carnot heat engine are derived. The optimal ecological performance of the heat engine in the classical limit is analyzed with numerical examples. Effects of internal irreversibility and heat leakage on the ecological performance are discussed. A performance comparison of the quantum heat engine under maximum ecological function and maximum power conditions is also performed.

  6. Irreversibility of financial time series: A graph-theoretical approach

    Science.gov (United States)

    Flanagan, Ryan; Lacasa, Lucas

    2016-04-01

    The relation between time series irreversibility and entropy production has been recently investigated in thermodynamic systems operating away from equilibrium. In this work we explore this concept in the context of financial time series. We make use of visibility algorithms to quantify, in graph-theoretical terms, time irreversibility of 35 financial indices evolving over the period 1998-2012. We show that this metric is complementary to standard measures based on volatility and exploit it to both classify periods of financial stress and to rank companies accordingly. We then validate this approach by finding that a projection in principal components space of financial years, based on time irreversibility features, clusters together periods of financial stress from stable periods. Relations between irreversibility, efficiency and predictability are briefly discussed.

  7. Variable Quotas, Irreversible Investment and Optimal Capacity in the Fisheries

    Directory of Open Access Journals (Sweden)

    Sjur D. Flåm

    1986-04-01

    Full Text Available We study the adaptation of a fishing fleet to a situation involving variable quotas of catch and irreversible investment. The theoretical results obtained here are applied to Norwegian industrial fisheries.

  8. Irreversible magnetic processes under biaxial and uniaxial magnetic anisotropies

    Directory of Open Access Journals (Sweden)

    S. Pokharel

    2016-05-01

    Full Text Available Irreversible magnetic processes have been investigated in magnetic systems with two different anisotropy symmetries (uniaxial and biaxial through angular measurement of the switching field, the irreversible susceptibility and the magnetic viscosity. These two systems consist of two-dimensional cobalt ferrite hetero-structures epitaxially grown on (100 and (110 MgO substrate. It is found that for uniaxial anisotropy the irreversible characteristics of the magnetization are large and display a strong angular dependence, which exhibits its maximum at the easy axis and drops quickly to vanish at the hard axis. However, for biaxial anisotropy the magnetization irreversible characteristics are considerably reduced and are less sensitive to the field angle.

  9. Microscopic reversibility and macroscopic irreversibility: A lattice gas model

    Science.gov (United States)

    Pérez-Cárdenas, Fernando C.; Resca, Lorenzo; Pegg, Ian L.

    2016-09-01

    We present coarse-grained descriptions and computations of the time evolution of a lattice gas system of indistinguishable particles, whose microscopic laws of motion are exactly reversible, in order to investigate how or what kind of macroscopically irreversible behavior may eventually arise. With increasing coarse-graining and number of particles, relative fluctuations of entropy rapidly decrease and apparently irreversible behavior unfolds. Although that behavior becomes typical in those limits and within a certain range, it is never absolutely irreversible for any individual system with specific initial conditions. Irreversible behavior may arise in various ways. We illustrate one possibility by replacing detailed integer occupation numbers at lattice sites with particle probability densities that evolve diffusively.

  10. Irreversibility and entanglement spectrum statistics in quantum circuits

    International Nuclear Information System (INIS)

    We show that in a quantum system evolving unitarily under a stochastic quantum circuit the notions of irreversibility, universality of computation, and entanglement are closely related. As the state evolves from an initial product state, it gets asymptotically maximally entangled. We define irreversibility as the failure of searching for a disentangling circuit using a Metropolis-like algorithm. We show that irreversibility corresponds to Wigner–Dyson statistics in the level spacing of the entanglement eigenvalues, and that this is obtained from a quantum circuit made from a set of universal gates for quantum computation. If, on the other hand, the system is evolved with a non-universal set of gates, the statistics of the entanglement level spacing deviates from Wigner–Dyson and the disentangling algorithm succeeds. These results open a new way to characterize irreversibility in quantum systems

  11. Towards irreversibility with a finite bath of oscillators

    International Nuclear Information System (INIS)

    We investigate the routes by which a bath composed of a finite number of oscillators at zero temperature approaches the induction of dissipation when it nears the usual limit of dense spectrum spread in an infinite interval. It is shown that, when this limit is taken, different distributions of environment frequencies can lead to the same irreversible evolution. However, when we move away from it, the dynamics departs from irreversibility in qualitatively different manners.

  12. Hydrodynamic Irreversibility in Particle Suspensions with Non-Uniform Strain

    OpenAIRE

    Guasto, Jeffrey S.; Ross, Andrew S.; Gollub, J. P.

    2010-01-01

    A dynamical phase transition from reversible to irreversible behavior occurs when particle suspensions are subjected to uniform oscillatory shear, even in the Stokes flow limit. We consider a more general situation with non-uniform strain (e.g. oscillatory channel flow), which is observed to exhibit markedly different dynamics. Self-organization and shear-induced migration only partially explain the delayed, simultaneous onset of irreversibility across the channel. The onset of irreversibilit...

  13. Mandatory Unbundling and Irreversible Investment in Telecom Networks

    OpenAIRE

    Robert S. Pindyck

    2004-01-01

    This paper addresses the impact on investment incentives of the network sharing arrangements mandated by the Telecommunications Act of 1996, with a focus on the implications of irreversible investment. Although the goal is to promote competition, the sharing rules now in place reduce incentives to build new networks or upgrade existing ones. Such investments are irreversible -- they involve sunk costs. The basic framework adopted by regulators allows entrants to utilize such facilities at pri...

  14. Irreversible electroporation of lung neoplasm: A case series

    OpenAIRE

    Usman, Mumal; Moore, William; Talati, Ronak; Watkins, Kevin; Bilfinger, Thomas V.

    2012-01-01

    Summary Background Percutaneous irreversible electroporation (IRE) of lung tumors is a new minimally invasive technique which has recently been used in the treatment of soft tissue tumors. Case Reports The case histories are presented of two patients with unresectable malignancies in the lung, who underwent irreversible electroporation as a treatment attempt. The procedure was performed under CT guidance and was uneventful. Conclusions At follow up 6 months later, the tumors both appeared to ...

  15. por valores

    Directory of Open Access Journals (Sweden)

    Jazmín Díaz-Barrios

    2005-01-01

    Full Text Available La era actual se caracteriza por una búsqueda de la identidad del hombre, donde el pivote del cambio organizacional es el individuo; cambiar en este entorno depende, en gran medida, de los valores que imperen en la cultura de la organización. Este trabajo documental intenta identificar aquellos valores, condición sine-qua-non, para el logro de los objetivos de cambio y analizarlos a fin de determinar sus indicadores, con el objeto de presentar una herramienta a las organizaciones que les facilite adaptarse a los nuevos tiempos. Se encontró que los valores: Delegación, Comunicación, Colaboración, Participación y Aprendizaje, son esenciales en los cambios integrales de esta era. Se determinaron 20 indicadores de su presencia. Se concluye que con esta información cada ente puede elaborar instrumentos que le permitan saber si los valores requeridos están presentes y en caso contrario tomar decisiones que alineen a la organización alrededor de los valores humanistas planteados, incrementando así las posibilidades de éxito en el proceso de cambio y por ende, las posibilidades de supervivencia en esta nueva época.

  16. Attribution of irreversible loss to anthropogenic climate change

    Science.gov (United States)

    Huggel, Christian; Bresch, David; Hansen, Gerrit; James, Rachel; Mechler, Reinhard; Stone, Dáithí; Wallimann-Helmer, Ivo

    2016-04-01

    The Paris Agreement (2015) under the UNFCCC has anchored loss and damage in a separate article which specifies that understanding and support should be enhanced in areas addressing loss and damage such as early warning, preparedness, insurance and resilience. Irreversible loss is a special category under loss and damage but there is still missing clarity over what irreversible loss actually includes. Many negative impacts of climate change may be handled or mitigated by existing risk management, reduction and absorption approaches. Irreversible loss, however, is thought to be insufficiently addressed by risk management. Therefore, countries potentially or actually affected by irreversible loss are calling for other measures such as compensation, which however is highly contested in international climate policy. In Paris (2015) a decision was adopted that loss and damage as defined in the respective article of the agreement does not involve compensation and liability. Nevertheless, it is likely that some sort of mechanism will eventually need to come into play for irreversible loss due to anthropogenic climate change, which might involve compensation, other forms of non-monetary reparation, or transformation. Furthermore, climate litigation has increasingly been attempted to address negative effects of climate change. In this context, attribution is important to understand the drivers of change, what counts as irreversible loss due to climate change, and, possibly, who or what is responsible. Here we approach this issue by applying a detection and attribution perspective on irreversible loss. We first analyze detected climate change impacts as assessed in the IPCC Fifth Assessment Report. We distinguish between irreversible loss in physical, biological and human systems, and accordingly identify the following candidates of irreversible loss in these systems: loss of glaciers and ice sheets, loss of subsurface ice (permafrost) and related loss of lake systems; loss

  17. Cyclosporine restores hematopoietic function by compensating for decreased Tregs in patients with pure red cell aplasia and acquired aplastic anemia.

    Science.gov (United States)

    Dao, An T T; Yamazaki, Hirohito; Takamatsu, Hiroyuki; Sugimori, Chiharu; Katagiri, Takamasa; Maruyama, Hiroyuki; Zaimoku, Yoshitaka; Maruyama, Kana; Ly, Trung Q; Espinoza, Luis; Nakao, Shinji

    2016-04-01

    Most patients with acquired pure red cell aplasia (PRCA) and some with acquired aplastic anemia (AA) respond well to cyclosporine (CsA), but thereafter often show CsA dependency. The mechanism underlying this dependency remains unknown. We established a reliable method for measuring the regulatory T cell (Treg) count using FoxP3 and Helios expression as markers and determined the balance between Tregs and other helper T cell subsets in 16 PRCA and 29 AA patients. The ratios of interferon-γ-producing CD4(+) (Th1) T cells to Tregs in untreated patients and CsA-dependent patients were significantly higher (PRCA 5.77 ± 1.47 and 7.38 ± 2.58; AA 6.18 ± 2.35 and 8.94 ± 4.06) than in healthy volunteers (HVs; 3.33 ± 0.90) due to the profound decrease in the percentage of Tregs. In contrast, the ratios were comparable to HVs in convalescent CsA-treated AA patients (4.74 ± 2.10) and AA patients in remission after the cessation of CsA treatment (4.24 ± 1.67). Low-dose CsA (100 ng/ml) inhibited the proliferation of conventional T cells (Tconv) to a similar degree to the inhibition by Tregs in a co-culture with a 1:1 Treg/Tconv ratio. The data suggest that CsA may reverse the hematopoietic suppression in PRCA and AA patients by compensating for the inadequate immune regulatory function that occurs due to a profound decrease in the Treg count. PMID:26968551

  18. A criterion to maximize the irreversible efficiency in heat engines

    International Nuclear Information System (INIS)

    The purpose of this work is to obtain a more precise calculation of the effective limits to the efficiency, of several cyclic heat engines. This calculation is based, first, on the equations describing the irreversible efficiency, and second, on a method which results from a general criterion to maximize this efficiency, applicable to several heat engines. With this method, we apply the criterion to maximize efficiencies; establish lower and upper bounds, corresponding to the efficiencies of Curzon-Ahlborn-like and Carnot-like heat engines; and, finally, find analytical or numerical expressions for the efficiencies ηme and ηmax. ηmax is the maximum irreversible efficiency; ηme is the efficiency in which the irreversible efficiency achieves its maximum, in a similar way to the Curzon-Ahlborn efficiency (maximum work or power). The method was applied to a Brayton cycle, presenting internal dissipations of the working fluid and irreversibilities due to the finite-rate heat transfer between the heat engine and its reservoirs. Also, we applied this method to a Carnot cycle including the irreversibilities of a finite-rate heat transfer between the heat engine and its reservoirs, heat leak between the reservoirs, and internal dissipations of the working fluid. The results obtained for the Brayton cycle are more general and useful than those in the relevant literature

  19. Improvement in Erythropoieis-stimulating Agent-induced Pure Red-cell Aplasia by Introduction of Darbepoetin-α When the Anti-erythropoietin Antibody Titer Declines Spontaneously

    OpenAIRE

    Lee, Hajeong; Yang, Jaeseok; Kim, Hyosang; Kwon, Ju Won; Oh, Kook-Hwan; Joo, Kwon Wook; Kim, Yon Su; Ahn, Curie; Han, Jin Suk; Kim, Suhnggwon

    2010-01-01

    Anti-erythropoietin antibodies usually cross-react with all kinds of recombinant erythropoietins; therefore, erythropoiesis-stimulating agent (ESA)-induced pure red-cell aplasia (PRCA) is not rescued by different ESAs. Here, we present a case of ESA-induced PRCA in a 36-yr-old woman with chronic kidney disease, whose anemic condition improved following reintroduction of darbepoetin-α. The patient developed progressive, severe anemia after the use of erythropoietin-α. As the anemia did not imp...

  20. Coombs-negative Autoimmune Hemolytic Anemia Followed by Anti-erythropoetin Receptor Antibody-associated Pure Red Cell Aplasia: A Case Report and Review of Literature.

    Science.gov (United States)

    Yoshimi, Mayumi; Kadowaki, Yutaka; Kikuchi, Yuji; Takahashi, Tsuyoshi

    2016-01-01

    A 76-year-old woman was referred to our hospital because of anemia. The laboratory findings revealed hemolysis. Although a direct Coombs test was negative, a high titer of RBC-bound IgG was detected, and a diagnosis of Coombs-negative autoimmune hemolytic anemia was made. She was successfully treated with prednisolone. One year and five months later, she again presented anemia and was diagnosed with pure red cell aplasia. Anti-erythropoietin receptor antibody was detected in the serum. She was treated with cyclosporine and obtained prompt recovery. We herein report this rare case and review the pertinent literature. PMID:26935373

  1. Irreversibilidad y pluralismo ontológico Irreversibility and ontological pluralism

    Directory of Open Access Journals (Sweden)

    Martín Labarca

    2007-06-01

    Full Text Available El problema de la irreversibilidad encuentra su origen a fines del siglo xix y comienzos del siglo xx con los trabajos de Maxwell, Boltzmann y Gibbs. La controversia surge al intentar compatibilizar la evolución macroscópica irreversible de los sistemas termodinámicos con la dinámica t-invariante de sus constituyentes microscópicos. En la formulación tradicional de la mecánica estadística, la evolución irreversible se explica mediante la introducción de un grano grueso sobre la dinámica microscópica subyacente. Por este motivo, suele considerarse que la mecánica estadística sólo brinda una descripción subjetiva o meramente gnoseológica de la irreversibilidad. El propósito del presente trabajo consiste en impugnar las interpretaciones tradicionales de la irreversibilidad, poniendo de manifiesto que su único fundamento es la implícita adopción de un realismo metafísico que adjudica prioridad ontológica al mundo microscópico. Argumentaremos que las dificultades se disuelven cuando el problema es abordado sobre la base de un pluralismo ontológico de raíces kantianas, inspirado en el realismo internalista de Putnam. Desde esta perspectiva filosófica, la irreversibilidad macroscópica es una propiedad objetiva que no necesita ser explicada en términos microscópicos para adquirir legitimidad ontológica: el grano grueso que vincula ambas evoluciones no es más que la relación entre dos descripciones igualmente objetivas.The problem of irreversibility finds its roots at the end of 19th century and the beginning of 20th century with the works of Maxwell, Boltzmann and Gibbs. The controversy arises when trying to make compatible the irreversible macroscopic evolution of thermodynamics systems with t-invariant dynamics of its microscopic components. In the traditional approach of statistical mechanics, the irreversible evolution is explained by introducing a coarse grain on the underlying microscopic dynamics. For this reason

  2. Irreversibility of the two-dimensional enstrophy cascade

    CERN Document Server

    Piretto,; Boffetta, G

    2016-01-01

    We study the time irreversibility of the direct cascade in two-dimensional turbulence by looking at the time derivative of the square vorticity along Lagrangian trajectories, a quantity which we call metenstrophy. By means of extensive numerical simulations we measure the time irreversibility from the asymmetry of the PDF of the metenstrophy and we find that it increases with the Reynolds number of the cascade, similarly to what found in three-dimensional turbulence. A detailed analysis of the different contributions to the enstrophy budget reveals a remarkable difference with respect to what observed for the direct cascade, in particular the role of the statistics of the forcing to determine the degree of irreversibility.

  3. Irreversible magnetovolume effect in Nd7Rh3 single crystal

    International Nuclear Information System (INIS)

    Magnetovolume effect in Nd7Rh3 single crystal has been studied by measuring the magnetostriction as a function of external magnetic field at 4.2 K. An irreversible magnetovolume effect having a negative remanent volume magnetostriction was observed when the external magnetic field was applied along the b-axis. The irreversible magnetostrictive effect takes place in the longitudinal magnetostriction along the b-axis. The remanent magnetostriction along the b-axis relaxes after removing external magnetic field for several hours and equilibrium state is stabilized. - Highlights: → Magnetostriction measurements of Nd7Rh3 single crystal at 4.2 K were made. → An irreversible magnetovolume effect having a negative remanent volume magnetostriction was observed. → Magnetic after effect on the remanent magnetostriction was also observed.

  4. Reversible and Irreversible Binding of Nanoparticles to Polymeric Surfaces

    Directory of Open Access Journals (Sweden)

    Wolfgang H. Binder

    2009-01-01

    Full Text Available Reversible and irreversible binding of CdSe-nanoparticles and nanorods to polymeric surfaces via a strong, multiple hydrogen bond (= Hamilton-receptor/barbituric acid is described. Based on ROMP-copolymers, the supramolecular interaction on a thin polymer film is controlled by living polymerization methods, attaching the Hamilton-receptor in various architectures, and concentrations. Strong binding is observed with CdSe-nanoparticles and CdSe-nanorods, whose surfaces are equipped with matching barbituric acid-moieties. Addition of polar solvents, able to break the hydrogen bonds leads to the detachment of the nanoparticles from the polymeric film. Irreversible binding is observed if an azide/alkine-“click”-reaction is conducted after supramolecular recognition of the nanoparticles on the polymeric surface. Thus reversible or irreversible attachment of the nanosized objects can be achieved.

  5. Equilibrium, fluctuation relations and transport for irreversible deterministic dynamics

    CERN Document Server

    Colangeli, Matteo

    2011-01-01

    In a recent paper [M. Colangeli \\textit{et al.}, J.\\ Stat.\\ Mech.\\ P04021, (2011)] it was argued that the Fluctuation Relation for the phase space contraction rate $\\Lambda$ could suitably be extended to non-reversible dissipative systems. We strengthen here those arguments, providing analytical and numerical evidence based on the properties of a simple irreversible nonequilibrium baker model. We also consider the problem of response, showing that the transport coefficients are not affected by the irreversibility of the microscopic dynamics. In addition, we prove that a form of \\textit{detailed balance}, hence of equilibrium, holds in the space of relevant variables, despite the irreversibility of the phase space dynamics. This corroborates the idea that the same stochastic description, which arises from a projection onto a subspace of relevant coordinates, is compatible with quite different underlying deterministic dynamics. In other words, the details of the microscopic dynamics are largely irrelevant, for ...

  6. Hydraulically irreversible fouling on ceramic MF/UF membranes: comparison of fouling indices, foulant composition and irreversible pore narrowing

    KAUST Repository

    Shang, Ran

    2015-05-06

    The application of ceramic membranes in water treatment is becoming increasing attractive because of their long life time and excellent chemical, mechanical and thermal stability. However, fouling of ceramic membranes, especially hydraulically irreversible fouling, is still a critical aspect affecting the operational cost and energy consumption in water treatment plants. In this study, four ceramic membranes with pore sizes or molecular weight cut-off (MWCO) of 0.20 μm, 0.14 μm, 300 kDa and 50 kDa were compared during natural surface water filtration with respect to hydraulically irreversible fouling index (HIFI), foulant composition and narrowing of pore size due to the irreversible fouling. Our results showed that the hydraulically irreversible fouling index (HIFI) was proportional to the membrane pore size (r2=0.89) when the same feed water was filtrated. The UF membranes showed lower HIFI values than the MF membranes. Pore narrowing (internal fouling) was found to be a main fouling pattern of the hydraulically irreversible fouling. The internal fouling was caused by monolayer adsorption of foulants with different sizes that is dependent on the size of the membrane pore.

  7. The thermomechanics of nonlinear irreversible behaviors an introduction

    CERN Document Server

    Maugin, Gérard A

    1999-01-01

    In this invaluable book, macroscopic irreversible thermodynamics is presented in its realm and its splendor by appealing to the notion of internal variables of state. This applies to both fluids and solids with or without microstructures of mechanical or electromagnetic origin. This unmatched richness of essentially nonlinear behaviors is the result of the use of modern mathematical techniques such as convex analysis in a clear-cut framework which allows one to put under the umbrella of "irreversible thermodynamics" behaviors which until now have been commonly considered either not easily cove

  8. Infecção por Chryseobacterium indologenes: relato de um caso Chryseobacterium indologenes infection: a case report

    Directory of Open Access Journals (Sweden)

    Renata de Souza Ferreira

    2010-03-01

    Full Text Available Relatamos um caso de infecção por Chryseobacterium indologenes, presente na cultura de aspirado traqueal em paciente sob ventilação mecânica invasiva, revisando os aspectos epidemiológicos, microbiológicos e o tratamento na unidade de terapia intensiva. Paciente do sexo masculino, 30 anos, internado com quadro de aplasia de medula idiopática e neutropenia febril foi transferido para a unidade de terapia intensiva com quadro de broncopneumonia e sepse grave de origem pulmonar. A maioria dos casos já relatados de pacientes com infecção por Chryseobacterium indologenes apresentavam patologias graves associadas e infecções polimicrobianas que podem dificultar a interpretação da efetividade da terapia antimicrobiana contra este agente.A case of Chryseobacterium indologenes infection is reported, identified in an invasive mechanic ventilation patient's tracheal aspiration material. Epidemiological, microbiological, and intensive care unit therapy aspects are discussed. The patient was a 30 years-old male, admitted with idiopathic medullary aplasia and febrile neutropenia, referred to the intensive care unit with severe bronchopneumonia and sepsis of pulmonary origin. Most of the previously reported Chryseobacterium indologenes infection cases were associated with severe diseases and polymicrobial infections which could make difficult interpreting antimicrobial therapy options against this agent.

  9. Irreversible Encephalopathy After Treatment With High-Dose Intravenous Metronidazole

    NARCIS (Netherlands)

    Groothoff, Miriam V. R.; Hofmeijer, Jannette; Sikma, Maaike A.; Meulenbelt, Jan

    2010-01-01

    Background: Encephalopathy associated with metronidazole is rare and, in most cases, reversible following discontinuation. Objective: We describe a case of fatal encephalopathy after treatment with high-dose intravenous metronidazole and the potential causes of the irreversibility. Case summary: A 3

  10. When an Adiabatic Irreversible Expansion or Compression Becomes Reversible

    Science.gov (United States)

    Anacleto, Joaquim; Ferreira, J. M.; Soares, A. A.

    2009-01-01

    This paper aims to contribute to a better understanding of the concepts of a "reversible process" and "entropy". For this purpose, an adiabatic irreversible expansion or compression is analysed, by considering that an ideal gas is expanded (compressed), from an initial pressure P[subscript i] to a final pressure P[subscript f], by being placed in…

  11. Intrinsic Decoherence and Irreversibility in the Quasiperiodic Kicked Rotor

    CERN Document Server

    Shifino, A C S; Siri, R; Romanelli, A; Donangelo, R J

    2003-01-01

    We show that some classically chaotic quantum systems uncoupled from noisy environments may generate intrinsic decoherence with all its associated effects. In particular, we have observed time irreversibility and high sensitivity to small perturbations in the initial conditions in a quasiperiodic version of the kicked rotor. The existence of simple quantum systems with intrinsic decoherence clarifies the quantum--classical correspondence in chaotic systems.

  12. Percutaneous Approach to Irreversible Electroporation of the Pancreas: Miami Protocol.

    Science.gov (United States)

    Venkat, Shree; Hosein, Peter J; Narayanan, Govindarajan

    2015-09-01

    Despite advances in the treatment of unresectable locally advanced pancreatic cancer, outcomes remain poor. Irreversible electroporation is a nonthermal ablative modality whose role in the management of locally advanced pancreatic cancer is being studied. This review highlights patient selection, preparation, and follow-up as well as discusses the techniques to achieve safe and effective tumor ablation in this challenging location. PMID:26365545

  13. A criterion to maximize the irreversible efficiency in heat engines

    CERN Document Server

    Aragon-Gonzalez, G; Leon-Galicia, A; Musharrafie-Martinez, M

    2003-01-01

    The purpose of this work is to obtain a more precise calculation of the effective limits to the efficiency, of several cyclic heat engines. This calculation is based, first, on the equations describing the irreversible efficiency, and second, on a method which results from a general criterion to maximize this efficiency, applicable to several heat engines. With this method, we apply the criterion to maximize efficiencies; establish lower and upper bounds, corresponding to the efficiencies of Curzon-Ahlborn-like and Carnot-like heat engines; and, finally, find analytical or numerical expressions for the efficiencies eta sub m sub e and eta sub m sub a sub x. eta sub m sub a sub x is the maximum irreversible efficiency; eta sub m sub e is the efficiency in which the irreversible efficiency achieves its maximum, in a similar way to the Curzon-Ahlborn efficiency (maximum work or power). The method was applied to a Brayton cycle, presenting internal dissipations of the working fluid and irreversibilities due to th...

  14. Preparation of irreversible hydrocolloids to improve retention of complete dentures

    Directory of Open Access Journals (Sweden)

    Aleksov Ljiljana

    2008-01-01

    Full Text Available Introduction Precise reproduction of anatomical-morphological details of dentures support on working models presupposes adequate application of modern impression materials and casting procedure, as well as minimal dimensional change of these materials. The aim of the study: experimental and clinical research is connected to irreversible hydrocolloids and the objective was to examine the most suitable consistency of the alginate as the impression mass for the purpose of improving retention of complete dentures. Material and methods This research included 35 completely toothless patients, most of who had already had complete dentures, 40-80 years of age and of both sexes. Static adhesion was measured with aery late plates made of adequate corresponding and various models depending on consistency of the irreversible hydrocolloids. Each model was cut into three parts, the cuts obtained were mutually compared, and computerized graphic charts of each section were made. Results The results of the research show that there is a greater retention force in the acrylate plates obtained on models castled on an anatomical impression base taken with irreversible hydrocolloides of solid consistency. Analysis of the results shows such quality of impressed tissues that they are practically slightly displaced by the impressions regardless of the consistency of the material impressed. Conclusion In conclusion it is pointed out that the preparation of irreversible hydrocolloides must be carried out by strictly obeying the powder-water weight ratios. The sections of the models obtained by irreversible hydrocolloides of various consistencies, that is by applying different pressures, point to minimal displacement of tissues and great differences in the retention force in favor of the compressive impression.

  15. BNNT-mediated irreversible electroporatio: its potential on cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Vittoria Raffa, Cristina Riggio, Michael W. Smith, Kevin C. Jordan, Wei Cao, Alfred Cuschieri

    2012-10-01

    Tissue ablation, i.e., the destruction of undesirable tissues, has become an important minimally invasive technique alternative to resection surgery for the treatment of tumours. Several methods for tissue ablation are based on thermal techniques using cold, e.g. cryosurgery [1] or heat, e.g. radiofrequency [2] or high-intensity focused ultrasound [3] or nanoparticle-mediated irradiation [4]. Alternatively, irreversible electroporation (IRE) has been proposed as non thermal technique for minimally invasive tissue ablation based on the use of electrical pulses. When the electric field is applied to a cell, a change in transmembrane potential is induced, which can cause biochemical and physiological changes of the cell. When the threshold value of the transmembrane potential is exceeded, the cell membrane becomes permeable, thus allowing entrance of molecules that otherwise cannot cross the membrane [5]. A further increase in the electric field intensity may cause irreversible membrane permeabilization and cell death. These pulses create irreversible defects (pores) in the cell membrane lipid bilayer, causing cell death through loss of cell homeostasis [6]. This is desirable in tumour ablation in order to produce large cell death, without the use of cytostatic drugs. A study of Davalos, Mir and Rubinsky showed that IRE can ablate substantial volumes of tissue without inducing a thermal effect and therefore serve as an independent and new tissue ablation modality; this opened the way to the use of IRE in surgery [7]. Their finding was subsequently confirmed in studies on cells [8], small animal models [9] and in large animal models in the liver [10] and the heart [11]. The most important finding in these papers is that irreversible electroporation produces precisely delineated ablation zones with cell scale resolution between ablated and non-ablated areas, without zones in which the extent of damage changes gradually as during thermal ablation. Furthermore, it is

  16. Determinación irreversible a la floración del aguacate 'Hass' en Michoacán Irreversible determination to flowering for 'Hass' avocado in Michoacán

    Directory of Open Access Journals (Sweden)

    José Luis Rocha-Arroyo

    Full Text Available El objetivo de este estudio, fue precisar los periodos en que ocurre la determinación irreversible a la floración en yemas apicales de brotes vegetativos de los flujos de invierno, primavera y verano en huertos de aguacate con y sin riego establecidos en cuatro condiciones climáticas. El estudio se realizó durante 2006-2008, en seis huertos comerciales de aguacate 'Hass' en el estado de Michoacán, México. En cada huerto se seleccionaron 20 árboles y cada uno se etiquetaron 30 brotes de cada flujo vegetativo. Los tratamientos consistieron en anillado y defoliación de un brote por árbol cada quince días para cada flujo vegetativo. El clima, influyó sobre la fecha en que ocurrió la determinación irreversible a la floración en los brotes de los tres flujos vegetativos, ésta ocurrió más temprano en clima templado que en cálido. Después de la emergencia, los brotes del flujo de invierno requirieron más tiempo para alcanzar la determinación irreversible a la floración que en primavera y verano. La determinación irreversible a la floración en brotes de los flujos de invierno, primavera y verano ocurrió del 30 de mayo al 23 de julio, del 28 de mayo al 26 de septiembre y del 10 de junio al 15 de septiembre, respectivamente, y de 29 a 42 días más temprano en los huertos sin riego. En el desarrollo floral, el número de yemas determinadas irreversiblemente a la floración variaron de 3 a 4 en los brotes de invierno, de 3 a 5 en primavera y de 1 a 4 en verano.The aim of this study was to specify periods in which occurs irreversible determination to flowering in apical bud of vegetative sprout for winter, spring and summer flows in avocado orchards with and without irrigation set under four climatic conditions. The study was carried out during 2006-2008, in six commercial orchards for avocado 'Hass' in State of Michoacán, Mexico. In each orchard 20 trees were selected and in each one 30 sprouts of each vegetative flow were labeled

  17. Uncertainty, Irreversibility and the Timing Problems of Environmental Policy

    Institute of Scientific and Technical Information of China (English)

    Yang Haisheng; Jia Jia; Zhou Yongzhang

    2006-01-01

    Most environmental issues and policy designing are uncertain and irreversible; therefore, the timing of environmental policy implementation becomes especially important. This paper establishes a random dynamic programming model and analyzes the optimal timing problems in environmental policy under uncertain variables. This model results indicate that two variables have a significant impact on the timing of environmental policy implementation and they work in opposite direcfons: on one hand, the more uncertain the economy is, the higher the cost of policies implementation will be, and consequently the incentive to immediately adopt the policy will be stronger. On the other hand, the higher the uncertainty of the environment is, the stronger the irreversibility of ecological harm caused by pollutants per unit will be. Therefore, the government should implement new environmental policies as early as possible in order to gain more ecological benefits.

  18. A unified viscoplasticity constitutive model based on irreversible thermodynamics

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    A unified viscoplasticity constitutive model for metal materials is developed within the framework of irreversible thermodynamics, and an expression for the Helmholtz free energy function involving the parameters reflecting kinematic hardening and isotropic hardening is given. At the same time a non-associated flow potential function including the corresponding state variables is also given, from which the flow equation and the evolution equations of the internal state variables are derived. Thus, a general theoretical framework constructing a unified viscoplasticity constitutive model is given. Compared with the typical unified viscoplasticity constitutive models, the presented model evidently satisfies the irreversible thermodynamics laws. Moreover, this method not only provides a new theoretical foundation for further development of the unified viscoplasticity constitutive model, but also gives a new theoretical framework for the stress-strain analysis of more materials.

  19. Irreversible adsorption of phenolic compounds by activated carbons

    International Nuclear Information System (INIS)

    Studies were undertaken to determine the reasons why phenolic sorbates can be difficult to remove and recover from activated carbons. The chemical properties of the sorbate and the adsorbent surface, and the influences of changes in the adsorption and desorption conditions were investigated. Comparison of isotherms established after different contact times or at different temperatures indicated that phenolic compounds react on carbon surfaces. The reaction rate is a strong function of temperature. Regeneration of carbons by leaching with acetone recovered at least as much phenol as did regeneration with other solvents or with displacers. The physiochemical properties of adsorbents influences irreversible uptakes. Sorbates differed markedly in their tendencies to undergo irreversible adsorption. 64 refs., 47 figs., 32 tabs

  20. Dynamics of polydisperse irreversible adsorption: a pharmacological example

    CERN Document Server

    Erban, R; Fisher, K D; Kevrekidis, Yu G; Seymour, L W; Chapman, Jonathan; Erban, Radek; Fisher, Kerry D.; Kevrekidis, Ioannis G.; Seymour, Leonard W.

    1999-01-01

    Many drug delivery systems suffer from undesirable interactions with the host immune system. It has been experimentally established that covalent attachment (irreversible adsorption) of suitable macromolecules to the surface of the drug carrier can reduce such undesirable interactions. A fundamental understanding of the adsorption process is still lacking. In this paper, the classical random irreversible adsorption model is generalized to capture certain essential processes involved in pharmacological applications, allowing for macromolecules of different sizes, partial overlapping of the tails of macromolecules, and the influence of reactions with the solvent on the adsorption process. Working in one dimension, an integro-differential evolution equation for the adsorption process is derived and the asymptotic behaviour of the surface area covered and the number of molecules attached to the surface is studied. Finally, equation-free dynamic renormalization tools are applied to study the asymptotically self-si...

  1. Ecological optimization for an irreversible magnetic Ericsson refrigeration cycle

    Institute of Scientific and Technical Information of China (English)

    Wang Hao; Wu Guo-Xing

    2013-01-01

    An irreversible Ericsson refrigeration cycle model is established,in which multi-irreversibilities such as finite-rate heat transfer,regenerative loss,heat leakage,and the efficiency of the regenerator are taken into account.Expressions for several important performance parameters,such as the cooling rate,coefficient of performance (COP),power input,exergy output rate,entropy generation rate,and ecological function are derived.The influences of the heat leakage and the time of the regenerative processes on the ecological performance of the refrigerator are analyzed.The optimal regions of the ecological function,cooling rate,and COP are determined and evaluated.Furthermore,some important parameter relations of the refrigerator are revealed and discussed in detail.The results obtained here have general significance and will be helpful in gaining a deep understanding of the magnetic Ericsson refrigeration cycle.

  2. Thermodynamic Analysis of the Irreversibilities in Solar Absorption Refrigerators

    Directory of Open Access Journals (Sweden)

    Emma Berrich Betouche

    2016-03-01

    Full Text Available A thermodynamic analysis of the irreversibility on solar absorption refrigerators is presented. Under the hierarchical decomposition and the hypothesis of an endoreversible model, many functional and practical domains are defined. The effect of external heat source temperature on the entropy rate and on the inverse specific cooling load (ISCL multiplied by the total area of the refrigerator A/Qe are studied. This may help a constructor to well dimension the solar machine under an optimal technico-economical criterion A/Qe and with reasonable irreversibility on the refrigerator. The solar concentrator temperature effect on the total exchanged area, on the technico-economical ratio A/Qe, and on the internal entropy rate are illustrated and discussed. The originality of these results is that they allow a conceptual study of a solar absorption refrigeration cycle.

  3. Comparison of reversible and irreversible dipolar assemblies in a ferrofluid

    Energy Technology Data Exchange (ETDEWEB)

    Klokkenburg, M. [Van' t Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute, Utrecht University, Padualaan 8, 3584 CH Utrecht (Netherlands)]. E-mail: m.klokkenburg@chem.uu.nl; Erne, B.H. [Van' t Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute, Utrecht University, Padualaan 8, 3584 CH Utrecht (Netherlands)

    2006-11-15

    Zero-field aggregation of magnetic nanoparticles in a ferrofluid can either be irreversible or result from a dynamic equilibrium; the two cases can be distinguished by measurements of the complex magnetic susceptibility and by cryogenic transmission electron microscopy (cryo-TEM). We demonstrate this by comparing two colloidal systems that show dipolar structure formation in zero field. A dispersion of magnetic iron nanoparticles is gradually oxidized to decrease the magnetic moments, and despite the vanishing dipolar attractions, thermal motion does not break up the dipolar structures into single particles. Instead, the dipolar structures become chemically fixed during the oxidation process, an example of irreversible aggregation. In contrast, the zero-field dipolar structures in a chemically stable magnetite dispersion are found to disintegrate upon dilution, indicating that the structures are reversible and result from a dynamic equilibrium.

  4. Thermodynamic irreversibility and performance characteristics of thermoelectric power generator

    International Nuclear Information System (INIS)

    Thermodynamic irreversibility and performance characteristics of a thermoelectric power generator are investigated. The influence of the external load parameter, the thermal conductivity ratio, the figure of Merit, and the conductance ratio on the efficiency, the output power, and the entropy generation rate is predicted for various device operating parameters. It is found that the device efficiency increases to reach its maximum at the critical value of the output power and operating the device beyond the critical output power lowers the thermal efficiency and enhances the entropy generation rate significantly in the device. - Highlights: • The thermodynamic irreversibility in thermoelectric generator is studied. • Thermodynamic characteristics of thermoelectric device are investigated. • Influence of various parameters on performance is presented. • The device efficiency reaches its maximum at a critical output power. • The entropy generation increases beyond the critical output power

  5. Ecological optimization for an irreversible magnetic Ericsson refrigeration cycle

    International Nuclear Information System (INIS)

    An irreversible Ericsson refrigeration cycle model is established, in which multi-irreversibilities such as finite-rate heat transfer, regenerative loss, heat leakage, and the efficiency of the regenerator are taken into account. Expressions for several important performance parameters, such as the cooling rate, coefficient of performance (COP), power input, exergy output rate, entropy generation rate, and ecological function are derived. The influences of the heat leakage and the time of the regenerative processes on the ecological performance of the refrigerator are analyzed. The optimal regions of the ecological function, cooling rate, and COP are determined and evaluated. Furthermore, some important parameter relations of the refrigerator are revealed and discussed in detail. The results obtained here have general significance and will be helpful in gaining a deep understanding of the magnetic Ericsson refrigeration cycle. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  6. Irreversible Electroporation of Human Primary Uveal Melanoma in Enucleated Eyes

    OpenAIRE

    Mandel, Yossi; Laufer, Shlomi; Belkin, Michael; Rubinsky, Boris; Pe'er, Jacob; Frenkel, Shahar

    2013-01-01

    Uveal melanoma (UM) is the most common primary intraocular tumor in adults and is characterized by high rates of metastatic disease. Although brachytherapy is the most common globe-sparing treatment option for small- and medium-sized tumors, the treatment is associated with severe adverse reactions and does not lead to increased survival rates as compared to enucleation. The use of irreversible electroporation (IRE) for tumor ablation has potential advantages in the treatment of tumors in com...

  7. Thermodynamic Analysis of the Irreversibilities in Solar Absorption Refrigerators

    OpenAIRE

    Emma Berrich Betouche; Ali Fellah; Ammar Ben Brahim; Fethi Aloui; Michel Feidt

    2016-01-01

    A thermodynamic analysis of the irreversibility on solar absorption refrigerators is presented. Under the hierarchical decomposition and the hypothesis of an endoreversible model, many functional and practical domains are defined. The effect of external heat source temperature on the entropy rate and on the inverse specific cooling load (ISCL) multiplied by the total area of the refrigerator A/Qe are studied. This may help a constructor to well dimension the solar machine under an optimal tec...

  8. Study of irreversible thermochromic ink application on textiles

    OpenAIRE

    Canal Barnils, Cristina; Villeger, Sandrine; Erra Serrabasa, Pilar; Ricard, André

    2009-01-01

    In the development of new products or new applications of known products, investigations have to be carried out concerning the choice of the kind of thermochromic matter, support, application form, concerning the evolution of colour change and stability versus imposed external parameters. The present paper studies the application of an irreversible thermochromic ink for the development of new high added value textiles, which may be prone to applications such as plasma treatments at low ...

  9. Irreversible Investment, Capacity Choice, and the Value of the Firm

    OpenAIRE

    Robert S. Pindyck

    1986-01-01

    A model of capacity choice and utilization is developed consistent with value maximization when investment is irreversible and future demand is uncertain. Investment requires the full value of a marginal unit of capacity to be at least as large as its full cost. The former includes the value of the firms option not to utilize the unit, and the latter includes the opportunity cost of exercising the investment option. We show that for moderate amounts of uncertainty, the firm's optimal capacity...

  10. Cell Death Characterization In Tumor Constructs Using Irreversible Electroporation

    OpenAIRE

    Prokop, Katherine Jane

    2013-01-01

    Cell Death Characterization in Tumor Constructs Using Irreversible Electroporation Katherine Jane Prokop ABSTRACT Pancreatic and prostate cancer are both prevalent cancers in the United States with pancreatic being one of the most aggressive of all cancers and prostate cancer being one of the most common, ranking as the number one cancer in men. Treatment of both cancers can be quite challenging as the anatomy of the pancreas and prostate, as well as the development and diagnos...

  11. Advancements in Irreversible Electroporation for the Treatment of Cancer

    OpenAIRE

    Arena, Christopher Brian

    2013-01-01

        Irreversible electroporation has recently emerged as an effective focal ablation technique. When performed clinically, the procedure involves placing electrodes into, or around, a target tissue and applying a series of short, but intense, pulsed electric fields. Oftentimes, patient specific treatment plans are employed to guide procedures by merging medical imaging with algorithms for determining the electric field distribution in the tissue. The electric field dictates treatment outcomes...

  12. Irreversible Electroporation: A Novel Image-Guided Cancer Therapy

    OpenAIRE

    Lee, Edward W.; Thai, Susan; Kee, Stephen T.

    2010-01-01

    Irreversible electroporation (IRE) is a novel tumor ablation technique using a non-thermal energy to create innumerable permanent nanopores in the cell membrane to disrupt cellular homeostasis. This disruption of cellular homeostasis initiates apoptosis which leads to permanent cell death. In our translational research, we have demonstrated that IRE can be a safe, fast and powerful method of tumor treatment. In this review, we present an overview of IRE ablation including a brief history of I...

  13. Irreversibility and complex network behavior of stream flow fluctuations

    Science.gov (United States)

    Serinaldi, Francesco; Kilsby, Chris G.

    2016-05-01

    Exploiting the duality between time series and networks, directed horizontal visibility graphs (DHVGs) are used to perform an unprecedented analysis of the dynamics of stream flow fluctuations with focus on time irreversibility and long range dependence. The analysis relies on a large quality-controlled data set consisting of 699 daily time series recorded in the continental United States (CONUS) that are not affected by human activity and primarily reflects meteorological conditions. DHVGs allow a clear visualization and quantification of time irreversibility of flow dynamics, which can be interpreted as a signature of nonlinearity, and long range dependence resulting from the interaction of atmospheric, surface and underground processes acting at multiple spatio-temporal scales. Irreversibility is explored by mapping the time series into ingoing, outgoing, and undirected graphs and comparing the corresponding degree distributions. Using surrogate data preserving up to the second order linear temporal dependence properties of the observed series, DHVGs highlight the additional complexity introduced by nonlinearity into flow fluctuation dynamics. We show that the degree distributions do not decay exponentially as expected, but tend to follow a subexponential behavior, even though sampling uncertainty does not allow a clear distinction between apparent or true power law decay. These results confirm that the complexity of stream flow dynamics goes beyond a linear representation involving for instance the combination of linear processes with short and long range dependence, and requires modeling strategies accounting for temporal asymmetry and nonlinearity.

  14. Irreversibility in energy processes: Non-dimensional quantification and balance

    Science.gov (United States)

    Pons, Michel

    2004-06-01

    The concept of thermodynamic efficiency (ratio of real cycle efficiency by Carnot efficiency) is well-known. The concept of numbers of entropy-production and of exergy-loss proposed by A. Bejan are also known, but rarely used. The present study firstly evidences that these two last numbers are actually identical, thus being a common number of irreversibility, independent of the method used for obtaining it. The study also evidences a non-dimensional irreversibility balance that applies to any energy conversion process. This balance correlates the thermodynamic efficiency of a whole process (which in most cases equals the exergetic efficiency) and the numbers of irreversibility of the different components or sub-processes involved in this process. Moreover, the basic additivity of entropy-productions and exergy-losses is maintained in this balance. This balance applies to the basic cycles (heat-engines, refrigerators, heat-pumps and heat-transformers), either work- or heat-powered. It also applies to more complex cycles (heat-powered cycles consuming electricity, four-temperature heat-powered cycles, cogeneration processes), thus giving a robust framework for analyzing these cycles.

  15. Irreversible Electroporation for Focal Ablation at the Porta Hepatis

    International Nuclear Information System (INIS)

    Patients with chemotherapy-refractory liver metastases who are not candidates for surgery may be treated with focal ablation techniques with established survival benefits. Irreversible electroporation is the newest of these and has the putative advantages of a nonthermal action, preventing damage to adjacent biliary structures and bowel. This report describes the use of irreversible electroporation in a 61-year-old man with a solitary chemoresistant liver metastasis unsuitable for radiofrequency ablation as a result of its proximity to the porta hepatis. At 3 months, tumor size was decreased on computed tomography from 28 × 19 to 20 × 17 mm, representing stable disease according to the response evaluation criteria in solid tumors. This corresponded to a decrease in tumor volume size from 5.25 to 3.16 cm3. There were no early or late complications. Chemoresistant liver metastases in the proximity of the porta hepatis that are considered to be too high a risk for conventional surgery or thermal ablation may be considered for treatment by the novel ablation technique of irreversible electroporation.

  16. Irreversible Electroporation for Focal Ablation at the Porta Hepatis

    Energy Technology Data Exchange (ETDEWEB)

    Kasivisvanathan, Veeru, E-mail: vk103@ic.ac.uk [Imperial College London, Department of Radiology (United Kingdom); Thapar, Ankur, E-mail: a.thapar09@imperial.ac.uk; Oskrochi, Youssof, E-mail: Youssof.Oskrochi09@imperial.ac.uk [Imperial College London, Department of Surgery and Cancer (United Kingdom); Picard, John, E-mail: John.picard@imperial.nhs.uk [Imperial College Healthcare NHS Trust, Department of Anaesthesia (United Kingdom); Leen, Edward L. S., E-mail: Edward.leen@imperial.ac.uk [Imperial College London, Department of Radiology (United Kingdom)

    2012-12-15

    Patients with chemotherapy-refractory liver metastases who are not candidates for surgery may be treated with focal ablation techniques with established survival benefits. Irreversible electroporation is the newest of these and has the putative advantages of a nonthermal action, preventing damage to adjacent biliary structures and bowel. This report describes the use of irreversible electroporation in a 61-year-old man with a solitary chemoresistant liver metastasis unsuitable for radiofrequency ablation as a result of its proximity to the porta hepatis. At 3 months, tumor size was decreased on computed tomography from 28 Multiplication-Sign 19 to 20 Multiplication-Sign 17 mm, representing stable disease according to the response evaluation criteria in solid tumors. This corresponded to a decrease in tumor volume size from 5.25 to 3.16 cm{sup 3}. There were no early or late complications. Chemoresistant liver metastases in the proximity of the porta hepatis that are considered to be too high a risk for conventional surgery or thermal ablation may be considered for treatment by the novel ablation technique of irreversible electroporation.

  17. IRREVERSIBLE ASSETS ARE IN THE SYSTEM TO CIRCULATION OF CAPITAL OF ENTERPRISE

    OpenAIRE

    V. Shvets; Borisiyk, O.

    2010-01-01

    Essence of irreversible assets is considered. Circulation of irreversible assets is exposed. Certainly factor which influences on the size of capital of enterprise. The cost of the fixed assets of Ukraine is represented in 2000-2008 years.

  18. Irreversible dynamics, Onsager-Casimir symmetry, and an application to turbulence.

    Science.gov (United States)

    Ottinger, Hans Christian

    2014-10-01

    Irreversible contributions to the dynamics of nonequilibrium systems can be formulated in terms of dissipative, or irreversible, brackets. We discuss the structure of such irreversible brackets in view of a degeneracy implied by energy conservation, where we consider different types of symmetries of the bracket corresponding to the Onsager and Casimir symmetries of linear irreversible thermodynamics. Slip and turbulence provide important examples of antisymmetric irreversible brackets and offer guidance for the more general modeling of irreversible dynamics without entropy production. Conversely, turbulence modeling could benefit from elucidating thermodynamic structure. The examples suggest constructing antisymmetric irreversible brackets in terms of completely antisymmetric functions of three indices. Irreversible brackets without well-defined symmetry properties can arise for rare events, causing big configurational changes. PMID:25375452

  19. Ecological Optimization and Parametric Study of an Irreversible Regenerative Modified Brayton Cycle with Isothermal Heat Addition

    OpenAIRE

    Vivek Tiwari; Subhash Chandra Kaushik; Sudhir Kumar Tyagi

    2003-01-01

    Abstract: An ecological optimization along with a detailed parametric study of an irreversible regenerative Brayton heat engine with isothermal heat addition have been carried out with external as well as internal irreversibilities. The ecological function is defined as the power output minus the power loss (irreversibility) which is ambient temperature times the entropy generation rate. The external irreversibility is due to finite temperature difference between the heat engine and the exter...

  20. Dimensional Stability of Color-Changing Irreversible Hydrocolloids after Disinfection

    Directory of Open Access Journals (Sweden)

    Khaledi AAR

    2015-03-01

    Full Text Available Statement of Problem: Disinfection of dental impressions is a weak point in the dental hygiene chain. In addition, dental office personnel and dental technicians are endangered by cross-contamination. Objectives: This study aimed to investigate the dimensional stability of two color-changing irreversible hydrocolloid materials (IH after disinfection with glutaraldehyde. Materials and Methods: In this in vitro study, impressions were made of a master maxillary arch containing three reference inserts on the occlucal surface of the left and right maxillary second molars and in the incisal surface of the maxillary central incisors. Two types of color-changing irreversible hydrocolloid (tetrachrom, cavex were used. Glutaraldehyde 2% was used in two methods of spraying and immersion to disinfect the impressions. The control group was not disinfected. Casts were made of type IV gypsum. The linear dimensional change of the stone casts was measured with a profile projector. For statistical analysis, Kruskall-Wallis and Mann-Witney tests were used (α=0.05. Results: By immersion method, the casts fabricated from tetrachrom were 0.36% larger in the anteroposterior (AP and 0.05% smaller in cross arch (CA dimensions; however, the casts prepared after spraying of tetrachrom were 0.44% larger in the AP and 0.10% smaller in CA dimensions. The casts made from Cavex were 0.05% smaller in the AP and 0.02% smaller in CA dimensions after spraying and 0.01% smaller in the AP and 0.003% smaller in CA dimensions after immersion. Generally there were not significant differences in AP and CA dimensions of the experimental groups compared to the control (p > 0.05. Conclusions: Disinfection of the tested color-changing irreversible hydrocolloids by glutaraldahyde 2% did not compromise the accuracy of the obtained casts.

  1. Advertising and irreversible opinion spreading in complex social networks

    OpenAIRE

    Candia, Julián

    2009-01-01

    Irreversible opinion spreading phenomena are studied on small-world and scale-free networks by means of the magnetic Eden model, a nonequilibrium kinetic model for the growth of binary mixtures in contact with a thermal bath. In this model, the opinion of an individual is affected by those of their acquaintances, but opinion changes (analogous to spin flips in an Ising-like model) are not allowed. We focus on the influence of advertising, which is represented by external magnetic fields. The ...

  2. Irreversible inhibition of epithelial sodium channels by ultraviolet irradiation.

    OpenAIRE

    Cuthbert, A W; Fanestil, D. D.; Herrera, F. C.; Pryn, S. J.

    1982-01-01

    1 The effects of u.v. irradiation at 254 nm and 350 nm on sodium transport across frog skin epithelium have been investigated. 2 Irradiation at 254 nm but not at 350 nm produces a dose-dependent, functionally selective blockade of sodium transport. The effect is apparently due to the irreversible closure of apical sodium channels. 3 The amiloride-sensitive conductance was directly related to sodium transport as measured by short circuit current (SCC) both in normal and irradiated tissues, alt...

  3. Irreversible Electroporation in the Treatment of Hepatocellular Carcinoma.

    Science.gov (United States)

    Lencioni, Riccardo; Crocetti, Laura; Narayanan, Govindarajan

    2015-09-01

    Irreversible electroporation (IRE) is a new nonthermal ablation modality that can be used to treat primary and metastatic lesions in the liver. This article describes the way IRE works, reviews safety and efficacy data, and presents strategies and recommendations for its use in everyday practice. In a series of liver lesions of various histologies, initial success was 100%; local recurrence rates were greater in larger lesions. In another series of hepatocellular carcinoma only, there was a 79% complete response rate overall and 93% in lesions less than 3 cm. Safety is comparable with those of other ablation modalities. IRE has advantages over other ablation modalities with comparable success rates. PMID:26365542

  4. Intrinsic irreversibility limits the efficiency of multidimensional molecular motors

    Science.gov (United States)

    Jack, M. W.; Tumlin, C.

    2016-05-01

    We consider the efficiency limits of Brownian motors able to extract work from the temperature difference between reservoirs or from external thermodynamic forces. These systems can operate in a variety of modes, including as isothermal engines, heat engines, refrigerators, and heat pumps. We derive analytical results showing that certain classes of multidimensional Brownian motor, including the Smoluchowski-Feynman ratchet, are unable to attain perfect efficiency (Carnot efficiency for heat engines). This demonstrates the presence of intrinsic irreversibilities in their operating mechanism. We present numerical simulations showing that in some cases the loss process that limits efficiency is associated with vortices in the probability current.

  5. From Maximum Entropy Models to Non-Stationarity and Irreversibility

    Science.gov (United States)

    Cofre, Rodrigo; Cessac, Bruno; Maldonado, Cesar

    The maximum entropy distribution can be obtained from a variational principle. This is important as a matter of principle and for the purpose of finding approximate solutions. One can exploit this fact to obtain relevant information about the underlying stochastic process. We report here in recent progress in three aspects to this approach.1- Biological systems are expected to show some degree of irreversibility in time. Based on the transfer matrix technique to find the spatio-temporal maximum entropy distribution, we build a framework to quantify the degree of irreversibility of any maximum entropy distribution.2- The maximum entropy solution is characterized by a functional called Gibbs free energy (solution of the variational principle). The Legendre transformation of this functional is the rate function, which controls the speed of convergence of empirical averages to their ergodic mean. We show how the correct description of this functional is determinant for a more rigorous characterization of first and higher order phase transitions.3- We assess the impact of a weak time-dependent external stimulus on the collective statistics of spiking neuronal networks. We show how to evaluate this impact on any higher order spatio-temporal correlation. RC supported by ERC advanced Grant ``Bridges'', BC: KEOPS ANR-CONICYT, Renvision and CM: CONICYT-FONDECYT No. 3140572.

  6. Introduction to Irreversible Electroporation--Principles and Techniques.

    Science.gov (United States)

    Thomson, Kenneth R; Kavnoudias, Helen; Neal, Robert E

    2015-09-01

    Irreversible electroporation (IRE) is a novel nonthermal focal ablation technique that uses a series of brief but intense electric pulses delivered by paired electrodes into a targeted region of tissue, killing the cells by irreversibly disrupting cellular membrane integrity. Unlike other ablation methods, IRE has relatively little effect on connective tissues and nerves and has a low patient effect. The ability of IRE to achieve cell death immediately adjacent to large vessels without effect on the vessels themselves has raised the possibility of better treatment of advanced pancreatic cancer. Because of the low effect on the patient, IRE is well suited for use in conjunction with chemotherapeutic agents. The IRE effect is not uniform and is dependent on the intrinsic conductivity of the tissue, the number of pulses delivered, the current flow achieved, and the total time for the treatment. It is currently under investigation for a wide range of solid tumors and prostate cancer in humans and in animals in the breast, brain, and spinal cord. In clinical practice, IRE can be administered either percutaneously under imaging guidance or at open operation under direct vision. In animals there is some evidence of an immune response presumably due to exposure of the intracellular target material, resulting in a greater therapeutic effect. Unlike many other cancer treatments, IRE has been introduced for human clinical use at a very early stage of development of the technique and much of the basic understanding of how and when to use IRE is still under investigation. PMID:26365541

  7. Irreversible entropy model for damage diagnosis in resistors

    Science.gov (United States)

    Cuadras, Angel; Crisóstomo, Javier; Ovejas, Victoria J.; Quilez, Marcos

    2015-10-01

    We propose a method to characterize electrical resistor damage based on entropy measurements. Irreversible entropy and the rate at which it is generated are more convenient parameters than resistance for describing damage because they are essentially positive in virtue of the second law of thermodynamics, whereas resistance may increase or decrease depending on the degradation mechanism. Commercial resistors were tested in order to characterize the damage induced by power surges. Resistors were biased with constant and pulsed voltage signals, leading to power dissipation in the range of 4-8 W, which is well above the 0.25 W nominal power to initiate failure. Entropy was inferred from the added power and temperature evolution. A model is proposed to understand the relationship among resistance, entropy, and damage. The power surge dissipates into heat (Joule effect) and damages the resistor. The results show a correlation between entropy generation rate and resistor failure. We conclude that damage can be conveniently assessed from irreversible entropy generation. Our results for resistors can be easily extrapolated to other systems or machines that can be modeled based on their resistance.

  8. Ecological optimisation of an irreversible Stirling heat engine

    Energy Technology Data Exchange (ETDEWEB)

    He, J.; Chen, J. [Xiamen Univ. (China). Dept. of Physics; Wu, C. [US Naval Academy, Annapolis, MD (United States). Dept. of Mechanical Engineering

    2001-10-01

    A general cycle model of an irreversible Stirling heat engine using an ideal or Van der Waals gas as the working substance is established. It includes three main sources of the irreversibility such as the heat transfer across finite-temperature differences in the isothermal processes, the regenerative loss resulting from the non-perfect regeneration in the regenerator, and the heat leak loss between the external heat reservoirs. The ecological function is taken as an objective function for optimisation. The performance characteristics of the Stirling heat engine at maximum ecological function are revealed. They are compared with other performance characteristics of the Stirling heat engine at maximum power output and efficiency in order to expound the significance of the ecological objective function. The results obtained here are of importance in the optimal design and operation of real Stirling heat engines. Finally, it is pointed out that the results obtained in this paper are very general, from which the optimal performance of the Ericsson heat engine using an ideal gas as the working substance and the Carnot heat engine can be derived directly. (author)

  9. Carnot's cycle for small systems: irreversibility and cost of operations

    Science.gov (United States)

    Sekimoto; Takagi; Hondou

    2000-12-01

    In the thermodynamic limit, the existence of a maximal efficiency of energy conversion attainable by a Carnot cycle consisting of quasistatic isothermal and adiabatic processes precludes the existence of a perpetual machine of the second kind, whose cycles yield positive work in an isothermal environment. We employ the recently developed framework of the energetics of stochastic processes (called "stochastic energetics") to reanalyze the Carnot cycle in detail, taking account of fluctuations, without taking the thermodynamic limit. We find that in this nonmacroscopic situation both processes of connection to and disconnection from heat baths and adiabatic processes that cause distortion of the energy distribution are sources of inevitable irreversibility within the cycle. Also, the so-called null-recurrence property of the cumulative efficiency of energy conversion over many cycles and the irreversible property of isolated, purely mechanical processes under external "macroscopic" operations are discussed in relation to the impossibility of a perpetual machine, or Maxwell's demon. This analysis may serve as the basis for the design and analysis of mesoscopic energy converters in the near future. PMID:11138050

  10. When an adiabatic irreversible expansion or compression becomes reversible

    International Nuclear Information System (INIS)

    This paper aims to contribute to a better understanding of the concepts of a reversible process and entropy. For this purpose, an adiabatic irreversible expansion or compression is analysed, by considering that an ideal gas is expanded (compressed), from an initial pressure Pi to a final pressure Pf, by being placed in contact with a set of N work reservoirs with pressures decreasing (increasing) in a geometric or arithmetic progression. The gas entropy change ΔS is evaluated and it is clearly shown that ΔS > 0 for any finite N, but as the number of work reservoirs goes to infinity the entropy change goes to zero, i.e. the process becomes reversible. Additionally, this work draws attention to the work reservoir concept, which is virtually ignored in the literature, and to its analogy with the commonly used heat reservoir concept. Finally, it complements and reinforces an earlier study dealing with irreversible cooling or heating so that the synergy created by the two studies is important from both theoretical and educational standpoints

  11. Magnetic irreversibility and zero resistance in granular Y358 superconductor

    International Nuclear Information System (INIS)

    We report on magnetization and magnetoresistance measurements of polycrystalline Y3Ba5Cu8O18 superconductor (Y358), prepared by solid state reaction in order to study the correlation between the magnetic irreversibility line and the zero electric resistance as a function of applied field. The magnetization measurements were performed using a MPMS-XL SQUID magnetometer and the magnetoresistance measurements were made using a PPMS, both from Quantum Design, up to 1 T. The granular microstructure was confirmed by scanning electron microscopy. In this case the grain junctions are weaker than in the Y123 system and the effect of the applied field on the grain couplings is much stronger. Consequently, in our sample the zero resistance line shifts away from the irreversibility line and is lower by more than 15 K at 1 T. We explain our results in terms of the superconducting glass model and in comparison with results obtained in other materials from the YBaCuO family

  12. Irreversible entropy model for damage diagnosis in resistors

    Energy Technology Data Exchange (ETDEWEB)

    Cuadras, Angel, E-mail: angel.cuadras@upc.edu; Crisóstomo, Javier; Ovejas, Victoria J.; Quilez, Marcos [Instrumentation, Sensor and Interfaces Group, Electronic Engineering Department, Escola d' Enginyeria de Telecomunicació i Aeronàutica de Castelldefels EETAC, Universitat Politècnica de Catalunya, Barcelona Tech (UPC), Castelldefels-Barcelona (Spain)

    2015-10-28

    We propose a method to characterize electrical resistor damage based on entropy measurements. Irreversible entropy and the rate at which it is generated are more convenient parameters than resistance for describing damage because they are essentially positive in virtue of the second law of thermodynamics, whereas resistance may increase or decrease depending on the degradation mechanism. Commercial resistors were tested in order to characterize the damage induced by power surges. Resistors were biased with constant and pulsed voltage signals, leading to power dissipation in the range of 4–8 W, which is well above the 0.25 W nominal power to initiate failure. Entropy was inferred from the added power and temperature evolution. A model is proposed to understand the relationship among resistance, entropy, and damage. The power surge dissipates into heat (Joule effect) and damages the resistor. The results show a correlation between entropy generation rate and resistor failure. We conclude that damage can be conveniently assessed from irreversible entropy generation. Our results for resistors can be easily extrapolated to other systems or machines that can be modeled based on their resistance.

  13. Linking Drugs to Obscure Illnesses: Lessons from Pure Red Cell Aplasia, Nephrogenic Systemic Fibrosis, and Reye’s Syndrome. A Report From the Southern Network on Adverse Reactions (SONAR)

    OpenAIRE

    Bennett, Charles L.; Starko, Karen M.; Thomsen, Henrik S; Cowper, Shawn; Sartor, Oliver; Macdougall, Iain C.; Qureshi, Zaina P; Bookstaver, P. Brandon; Miller, April D; Norris, LeAnn B.; Xirasagar, Sudha; Trenery, Alyssa; Lopez, Isaac; Kahn, Adam; Murday, Alanna

    2012-01-01

    Identification of serious adverse drug reactions (sADRS) associated with commonly used drugs can elude detection for years. Reye’s syndrome (RS), nephrogenic systemic fibrosis (NSF), and pure red cell aplasia (PRCA) among chronic kidney disease (CKD) patients were recognized in 1951, 2000, and 1998, respectively. Reports associating these syndromes with aspirin, gadodiamide, and epoetin, were published 29, 6, and 4 years later, respectively. We obtained primary information from clinicians who...

  14. Application of exergy method to an irreversible inter-cooled refrigeration cycle

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C-K. [National Cheng-Kung University, Tainan (Taiwan). Department of Mechanical Engineering; Su, Y-F. [Far East College, Tainan (Taiwan). Department of Automation and Control Engineering

    2005-12-15

    The exergy method, based on the maximum exergetic efficiency criterion, has been applied to an irreversible inter-cooled refrigeration cycle. The exergetic efficiency defined as the ratio of the rate of exergy output to the rate of exergy input is taken as the objective function to be maximized. Multi-irreversibilities include finite-rate heat transfer, internal dissipation of the working fluid, and heat leaks between heat reservoirs. The maximum exergetic efficiency can be determined analytically by introducing the internal irreversibility parameter, which represents the degree of internal irreversibility. The corresponding performances of the irreversible refrigeration system are obtained simultaneously. The results show that the exergy method can be used as an effective criterion in designing an irreversible inter-cooled refrigeration system. (author)

  15. Irreversible Kidney Damage due to Multicentric Castleman’s Disease

    Directory of Open Access Journals (Sweden)

    Mårten Segelmark

    2008-01-01

    Full Text Available Castleman’s Disease (CD is a rare lymphoproliferative disorder accompanied by marked systemic inflammatory response. Morphological diagnosis of CD requires biopsy of the whole of the involved lymph node tissue. Three histologic variants have already been described in CD morphology (hyaline vascular, plasma-cell, and mixed. In this study, we report a case of a multicentric Castleman’s disease of the plasma cell variant type with negative Herpes Virus 8. The clinical presentation of this patient was of systemic amyloidosis as a result of both a delayed diagnosis and medical management. Previously described cases of CD with secondary amyloidosis have been of the localized type. Regardless, long-standing clinical remission of CD by cytotoxic drugs and anti-CD20 antibody therapy was achieved, but the nephrotic syndrome remained irreversible.

  16. Advertising and Irreversible Opinion Spreading in Complex Social Networks

    Science.gov (United States)

    Candia, Julián

    Irreversible opinion spreading phenomena are studied on small-world and scale-free networks by means of the magnetic Eden model, a nonequilibrium kinetic model for the growth of binary mixtures in contact with a thermal bath. In this model, the opinion of an individual is affected by those of their acquaintances, but opinion changes (analogous to spin flips in an Ising-like model) are not allowed. We focus on the influence of advertising, which is represented by external magnetic fields. The interplay and competition between temperature and fields lead to order-disorder transitions, which are found to also depend on the link density and the topology of the complex network substrate. The effects of advertising campaigns with variable duration, as well as the best cost-effective strategies to achieve consensus within different scenarios, are also discussed.

  17. Posterior encephalopathy subsequent to cyclosporin A presenting as irreversible abulia.

    Science.gov (United States)

    Nishie, Makoto; Kurahashi, Kozo; Ogawa, Masaya; Yoshida, Yasuji; Midorikawa, Hiroshi

    2003-08-01

    A case of cyclosporin A (Cys A)-induced posterior encephalopathy developed into persistent abulia despite rapid and marked improvement of abnormal T2- and FLAIR MRI hyperintense regions. Diffusion-weighted MRI signal intensity was also high at the onset. This change is atypical in Cys A-induced encephalopathy and was thought to predict poor recovery from the encephalopathy. Persistent abulia was probably due to marked hypoperfusion in the whole cortex including bilateral frontal lobes and basal ganglia as detected by SPECT. Apart from the breakdown of the blood-brain barrier, direct toxicity of Cys A to the brain may play a role in the pathogenesis of chronic, irreversible encephalopathy. PMID:12924507

  18. Focal Therapy of Prostate Cancer Using Irreversible Electroporation.

    Science.gov (United States)

    Valerio, Massimo; Ahmed, Hashim U; Emberton, Mark

    2015-09-01

    Focal therapy is a novel strategy that attempts to enhance the therapeutic ratio of standard radical treatment in prostate cancer. Irreversible electroporation (IRE) has some inherent characteristics that may be ideal for focal therapy. Precise confined ablation in the treatment area obtained via nonthermal damage with potential for minimal toxicity to surrounding structures may lead to optimal treatment with improved preservation of continence and erectile function. Initial data of focal IRE of the prostate are encouraging although further assessment is awaited to confirm these findings using robust methodology. In this article, we provide a comprehensive step-by-step description of our technique to deliver focal IRE in selected men with localized prostate cancer located in a discrete area of the prostate. PMID:26365544

  19. Irreversible degradation of quantum coherence under relativistic motion

    Science.gov (United States)

    Wang, Jieci; Tian, Zehua; Jing, Jiliang; Fan, Heng

    2016-06-01

    We study the dynamics of quantum coherence under Unruh thermal noise and seek under which condition the coherence can be frozen in a relativistic setting. We find that the frozen condition is either (i) the initial state is prepared as an incoherence state or (ii) the detectors have no interaction with the external field. That is to say, the decoherence of the detectors' quantum state is irreversible under the influence of thermal noise induced by Unruh radiation. It is shown that quantum coherence approaches zero only in the limit of an infinite acceleration, while quantum entanglement could reduce to zero for a finite acceleration. It is also demonstrated that the robustness of quantum coherence is better than entanglement under the influence of the atom-field interaction for an extremely large acceleration. Therefore, quantum coherence is more robust than entanglement in an accelerating system and the coherence-type quantum resources are more accessible for relativistic quantum information processing tasks.

  20. Irreversible Collective Migration of Cyanobacteria in Eutrophic Conditions

    CERN Document Server

    Dervaux, Julien; Brunet, Philippe

    2015-01-01

    In response to natural or anthropocentric pollutions coupled to global climate changes, microorganisms from aquatic environments can suddenly accumulate on water surface. These dense suspensions, known as blooms, are harmful to ecosystems and significantly degrade the quality of water resources. In order to determine the physico-chemical parameters involved in their formation and quantitatively predict their appearance, we successfully reproduced irreversible cyanobacterial blooms in vitro. By combining chemical, biochemical and hydrodynamic evidences, we identify a mechanism, unrelated to the presence of internal gas vesicles, allowing the sudden collective upward migration in test tubes of several cyanobacterial strains (Microcystis aeruginosa PCC 7005, Microcystis aeruginosa PCC 7806 and Synechocystis sp. PCC 6803). The final state consists in a foamy layer of biomass at the air-liquid interface, in which micro-organisms remain alive for weeks, the medium lying below being almost completely depleted of cya...

  1. Structural transition models for a class or irreversible aggregates

    International Nuclear Information System (INIS)

    A progress report on two recent theoretical approaches proposed to understand the physics of irreversible fractal aggregates showing up a structural transition from a rather dense to a more multibranched growth is presented. In the first approach the transition is understood by solving the Poisson equation on a squared lattice. The second approach is based on the discretization of the Biharmonic equation. Within these models the transition appears when the growth velocity at the fractal surface presents a minimum. The effects of the surrounding medium and geometrical constraints for the seed particles are considered. By using the optical diffraction method, the structural transition is further characterized by a decrease in the fractal dimension for this peculiar class of aggregates. (author). 17 refs, 4 figs

  2. Irreversible Work and Inner Friction in Quantum Thermodynamic Processes

    Science.gov (United States)

    Plastina, F.; Alecce, A.; Apollaro, T. J. G.; Falcone, G.; Francica, G.; Galve, F.; Lo Gullo, N.; Zambrini, R.

    2014-12-01

    We discuss the thermodynamics of closed quantum systems driven out of equilibrium by a change in a control parameter and undergoing a unitary process. We compare the work actually done on the system with the one that would be performed along ideal adiabatic and isothermal transformations. The comparison with the latter leads to the introduction of irreversible work, while that with the former leads to the introduction of inner friction. We show that these two quantities can be treated on an equal footing, as both can be linked with the heat exchanged in thermalization processes and both can be expressed as relative entropies. Furthermore, we show that a specific fluctuation relation for the entropy production associated with the inner friction exists, which allows the inner friction to be written in terms of its cumulants.

  3. Rat liver regeneration following ablation with irreversible electroporation.

    Science.gov (United States)

    Golberg, Alexander; Bruinsma, Bote G; Jaramillo, Maria; Yarmush, Martin L; Uygun, Basak E

    2016-01-01

    During the past decade, irreversible electroporation (IRE) ablation has emerged as a promising tool for the treatment of multiple diseases including hepatic cancer. However, the mechanisms behind the tissue regeneration following IRE ablation have not been investigated. Our results indicate that IRE treatment immediately kills the cells at the treatment site preserving the extracellular architecture, in effect causing in vivo decellularization. Over the course of 4 weeks, progenitor cell differentiation, through YAP and notch pathways, together with hepatocyte expansion led to almost complete regeneration of the ablated liver leading to the formation of hepatocyte like cells at the ablated zone. We did not observe significant scarring or tumor formation at the regenerated areas 6 months post IRE. Our study suggests a new model to study the regeneration of liver when the naïve extracellular matrix is decellularized in vivo with completely preserved extracellular architecture. PMID:26819842

  4. Sub-kBT micro-electromechanical irreversible logic gate

    Science.gov (United States)

    López-Suárez, M.; Neri, I.; Gammaitoni, L.

    2016-06-01

    In modern computers, computation is performed by assembling together sets of logic gates. Popular gates like AND, OR and XOR, processing two logic inputs and yielding one logic output, are often addressed as irreversible logic gates, where the sole knowledge of the output logic value is not sufficient to infer the logic value of the two inputs. Such gates are usually believed to be bounded to dissipate a finite minimum amount of energy determined by the input-output information difference. Here we show that this is not necessarily the case, by presenting an experiment where a OR logic gate, realized with a micro-electromechanical cantilever, is operated with energy well below the expected limit, provided the operation is slow enough and frictional phenomena are properly addressed.

  5. Constructal theory through thermodynamics of irreversible processes framework

    Energy Technology Data Exchange (ETDEWEB)

    Tescari, S.; Mazet, N. [PROMES-CNRS, Rambla de la Thermodynamique, Tecnosud, 66100 Perpignan (France); Neveu, P., E-mail: neveu@univ-perp.fr [PROMES-CNRS, Rambla de la Thermodynamique, Tecnosud, 66100 Perpignan (France); Universite de Perpignan Via Domitia, 52 Avenue Paul Alduy, 66860 Perpignan (France)

    2011-09-15

    Highlights: {yields} Point to area flow problem is solved through Thermodynamics of irreversible processes. {yields} A new optimisation criterion is defined: the exergy or entropy impedance. {yields} Optimisation is performed following two different routes, constructal or global. {yields} Global optimisation is more efficient than constructal optimisation. {yields} Global optimisation enhances the domain of construct benefits. - Abstract: Point to volume flow problem is revisited on a thermodynamics of irreversible processes (TIP) basis. The first step consists in evaluating the local entropy production of the system, and deducing from this expression the phenomenological laws. Then, the total entropy production can be simply evaluated. It is demonstrated that total entropy production can be written in a remarkable form: the product of the so-called entropy impedance with the square of the heat flux. As the heat flux is given, optimisation consists in minimising the entropy impedance. It is also shown that minimising entropy impedance minimises the maximum temperature difference. Applied to the elemental volume, this optimisation process leads to a shape factor close to the one already published. For the first construction, the equivalent system is defined as stated by Prigogine: when subjected to the same constraints, two systems are thermodynamically equivalent if their entropy production is equal. Two optimisation routes are then investigated: a global optimisation where all scales are taken into account and the constructal optimisation where the system is optimised scale by scale. In this second case, results are close to Ghodossi's work. When global optimisation is performed, it is demonstrated that conductive paths have to be spread uniformly in the active material (i.e. the number of elemental volumes must go to infinite). Comparing the two routes, global optimisation leads to better performance than constructal optimisation. Moreover, global

  6. Constructal theory through thermodynamics of irreversible processes framework

    International Nuclear Information System (INIS)

    Highlights: → Point to area flow problem is solved through Thermodynamics of irreversible processes. → A new optimisation criterion is defined: the exergy or entropy impedance. → Optimisation is performed following two different routes, constructal or global. → Global optimisation is more efficient than constructal optimisation. → Global optimisation enhances the domain of construct benefits. - Abstract: Point to volume flow problem is revisited on a thermodynamics of irreversible processes (TIP) basis. The first step consists in evaluating the local entropy production of the system, and deducing from this expression the phenomenological laws. Then, the total entropy production can be simply evaluated. It is demonstrated that total entropy production can be written in a remarkable form: the product of the so-called entropy impedance with the square of the heat flux. As the heat flux is given, optimisation consists in minimising the entropy impedance. It is also shown that minimising entropy impedance minimises the maximum temperature difference. Applied to the elemental volume, this optimisation process leads to a shape factor close to the one already published. For the first construction, the equivalent system is defined as stated by Prigogine: when subjected to the same constraints, two systems are thermodynamically equivalent if their entropy production is equal. Two optimisation routes are then investigated: a global optimisation where all scales are taken into account and the constructal optimisation where the system is optimised scale by scale. In this second case, results are close to Ghodossi's work. When global optimisation is performed, it is demonstrated that conductive paths have to be spread uniformly in the active material (i.e. the number of elemental volumes must go to infinite). Comparing the two routes, global optimisation leads to better performance than constructal optimisation. Moreover, global optimisation enlarges the domain of

  7. Multiple linear analysis methods for the quantification of irreversibly binding radiotracers

    OpenAIRE

    Kim, Su Jin; Lee, Jae Sung; Kim, Yu Kyeong; Frost, James; Wand, Gary; McCaul, Mary E.; Lee, Dong Soo

    2008-01-01

    Gjedde–Patlak graphical analysis (GPGA) has commonly been used to quantify the net accumulations (Kin) of radioligands that bind or are taken up irreversibly. We suggest an alternative approach (MLAIR: multiple linear analysis for irreversible radiotracers) for the quantification of these types of tracers. Two multiple linear regression model equations were derived from differential equations of the two-tissue compartment model with irreversible binding. Multiple linear analysis for irreversi...

  8. Irreversible injury of isolated adult rat myocytes. Osmotic fragility during metabolic inhibition.

    OpenAIRE

    Ganote, C. E.; Vander Heide, R. S.

    1988-01-01

    Isolated myocytes can be established as a valid model for studying changes in cytoskeletal proteins during the development of irreversible injury only if isolated cells develop lesions similar to those that occur during irreversible injury to intact hearts, specifically osmotic fragility and subsarcolemmal blebs. In the first experiment, isolated cells were irreversibly injured by metabolic inhibition with 5 mM Iodoacetic acid (IAA) and 6 mM amobarbital (Amy). Osmotic fragility of control and...

  9. Efficiency at maximum power output of linear irreversible Carnot-like heat engines

    OpenAIRE

    Wang, Yang; Tu, Z. C.

    2011-01-01

    The efficiency at maximum power output of linear irreversible Carnot-like heat engines is investigated based on the assumption that the rate of irreversible entropy production of working substance in each "isothermal" process is a quadratic form of heat exchange rate between the working substance and the reservoir. It is found that the maximum power output corresponds to minimizing the irreversible entropy production in two "isothermal" processes of the Carnot-like cycle, and that the efficie...

  10. Cooling load and COP optimization of an irreversible Carnot refrigerator with spin-1/2 systems

    OpenAIRE

    Xiaowei Liu, Lingen Chen, Feng Wu, Fengrui Sun

    2011-01-01

    A model of an irreversible quantum refrigerator with working medium consisting of many non-interacting spin-1/2 systems is established in this paper. The quantum refrigeration cycle is composed of two isothermal processes and two irreversible adiabatic processes and is referred to as a spin quantum Carnot refrigeration cycle. Expressions of some important performance parameters, such as cycle period, cooling load and coefficient of performance (COP) for the irreversible spin quantum Carnot re...

  11. Optimal fundamental characteristic of a quantum harmonic oscillator Carnot refrigerator with multi-irreversibilities

    OpenAIRE

    Xiaowei Liu, Lingen Chen, Feng Wu, Fengrui Sun

    2015-01-01

    The optimal performance of an irreversible quantum Carnot refrigerator with working medium consisting of many non-interacting harmonic oscillators is investigated in this paper. The quantum refrigerator cycle is composed of two isothermal processes and two irreversible adiabatic processes, and the irreversibilities of heat resistance, internal friction and bypass heat leakage are considered. By using the quantum master equation, semi-group approach and finite time thermodynamics (FTT), this p...

  12. Palliative treatment of presacral recurrence of endometrial cancer using irreversible electroporation: a case report

    OpenAIRE

    Niessen, Christoph; Jung, Ernst-Michael; Schreyer, Andreas G; Wohlgemuth, Walter A; Trabold, Benedikt; Hahn, Joachim; Rechenmacher, Michael; Stroszczynski, Christian; Wiggermann, Philipp

    2013-01-01

    INTRODUCTION: Irreversible electroporation (IRE) is a new minimally invasive tumor ablation technique which induces irreversible disruption of cell membrane integrity by changing the transmembrane potential resulting in cell death. Irreversible electroporation is currently undergoing clinical investigation as local tumor therapy for malignant liver and lung lesions. This is the first case report to describe the successful palliative ablation of a presacral recurrence of an endometrial canc...

  13. An irreversible Markov-chain Monte Carlo method with skew detailed balance conditions

    International Nuclear Information System (INIS)

    An irreversible Markov-chain Monte Carlo (MCMC) method based on a skew detailed balance condition is discussed. Some recent theoretical works concerned with the irreversible MCMC method are reviewed and the irreversible Metropolis-Hastings algorithm for the method is described. We apply the method to ferromagnetic Ising models in two and three dimensions. Relaxation dynamics of the order parameter and the dynamical exponent are studied in comparison to those with the conventional reversible MCMC method with the detailed balance condition. We also examine how the efficiency of exchange Monte Carlo method is affected by the combined use of the irreversible MCMC method

  14. Pure red cell aplasia due to parvovirus B19 infection after liver transplantation: A case report and review of the literature

    Institute of Scientific and Technical Information of China (English)

    Ting-Bo Liang; Shu-Sen Zheng; Dong-Lin Li; Jun Yu; Xue-Li Bai; Liang Liang; Shi-Guo Xu; Wei-Lin Wang; Yan Shen; Min Zhang

    2007-01-01

    Pure red cell aplasia (PRCA) due to parvovirus B19(PVB19) infection after solid organ transplantation has been rarely reported and most of the cases were renal transplant recipients. Few have been described after liver transplantation. Moreover, little information on the management of this easily recurring disease is available at present. We describe the first case of a Chinese liver transplant recipient with PVB19-induced PRCA during immunosuppressive therapy. The patient suffered from progressive anemia with the lowest hemoglobin level of 21 g/L. Bone marrow biopsy showed selectively inhibited erythropoiesis with giant pronormoblasts. Detection of PVB19-DNA in serum with quantitative polymerase chain reaction (PCR) revealed a high level of viral load.After 2 courses of intravenous immunoglobulin (IVIG)therapy, bone marrow erythropoiesis recovered with his hemoglobin level increased to 123 g/L. He had a lowlevel PVB19 load for a 5-mo follow-up period without recurrence of PRCA, and finally the virus was cleared.Our case indicates that clearance of PVB19 by IVIG in transplant recipients might be delayed after recovery of anemia.

  15. Neumonitis por hipersensibilidad asociado al cuidado de aves

    Directory of Open Access Journals (Sweden)

    Ana María González-Zúñiga

    2015-01-01

    Full Text Available La neumonitis por hipersensibilidad asociada al cuidado de las aves es uno de los tipos más frecuentes de esta que se presentan. Aunque no se tienen datos epidemiológicos claros sobre su prevalencia, en los hospitales llegan casos de este tipo. No es una patología muy común; sin embargo, una muestra representativa de la población se encuentra expuesta a las aves y, consecuentemente, a los antígenos que causan la enfermedad. Su diagnóstico temprano puede significar para el paciente evitar daños, al dejar de exponerse al antígeno; por el contrario, si no se realiza un diagnóstico temprano, puede generarse un daño pulmonar irreversible. En este artículo, se presenta un caso clínico de neumonitis por hipersensibilidad al cuidado de aves.

  16. Miocarditis por dengue

    OpenAIRE

    Ricardo Amador García Hernández; Fidel Espinosa Rivera; Lianet Rivero Seriel

    2013-01-01

    El dengue es un arbovirus transmitido por el Aedes aegypti, produce los cuadros clínicos de dengue clásico, dengue hemorrágico y síndrome de choque por dengue, aisladamente se reportan casos de miocarditis. Se presentó un paciente con antecedentes de dengue clásico que manifestó dolor precordial asociado a cambios electrocardiográficos y fue ingresado en este hospital por síndrome coronario agudo probable, al cual se le diagnosticó clínicamente miocarditis por dengue.

  17. Inertial effects during irreversible meniscus reconfiguration in angular pores

    Science.gov (United States)

    Ferrari, Andrea; Lunati, Ivan

    2014-12-01

    In porous media, the dynamics of the invading front between two immiscible fluids is often characterized by abrupt reconfigurations caused by local instabilities of the interface. As a prototype of these phenomena we consider the dynamics of a meniscus in a corner as it can be encountered in angular pores. We investigate this process in detail by means of direct numerical simulations that solve the Navier-Stokes equations in the pore space and employ the Volume of Fluid method (VOF) to track the evolution of the interface. We show that for a quasi-static displacement, the numerically calculated surface energy agrees well with the analytical solutions that we have derived for pores with circular and square cross sections. However, the spontaneous reconfigurations are irreversible and cannot be controlled by the injection rate: they are characterized by the amount of surface energy that is spontaneously released and transformed into kinetic energy. The resulting local velocities can be orders of magnitude larger than the injection velocity and they induce damped oscillations of the interface that possess their own time scales and depend only on fluid properties and pore geometry. In complex media (we consider a network of cubic pores) reconfigurations are so frequent and oscillations last long enough that increasing inertial effects leads to a different fluid distribution by influencing the selection of the next pore to be invaded. This calls into question simple pore-filling rules based only on capillary forces. Also, we demonstrate that inertial effects during irreversible reconfigurations can influence the work done by the external forces that is related to the pressure drop in Darcy's law. This suggests that these phenomena have to be considered when upscaling multiphase flow because local oscillations of the menisci affect macroscopic quantities and modify the constitutive relationships to be used in macro-scale models. These results can be extrapolated to other

  18. ESTIMATION OF IRREVERSIBLE DAMAGEABILITY AT FATIGUE OF CARBON STEEL

    Directory of Open Access Journals (Sweden)

    I. O. Vakulenko

    2014-04-01

    Full Text Available Purpose. Damageability estimation of carbon steel in the conditions of cyclic loading. Methodology. The steel fragments of railway wheel rim and rail head served as material for research with chemical composition 0.65 % С, 0.67 % Mn, 0.3 % Si, 0.027 % P, 0.028 % S и 0.7 % C, 0.82 % Mn, 0.56 % Si, 0.025 % P, 0.029 % S accordingly. The microstructure of tested steels corresponded to the state of metal after a hot plastic deformation. The fatigue research was conducted in the conditions of symmetric bend using the proof-of-concept machine of type «Saturn-10». Full Wohler diagrams and the lines corresponding to forming of sub-and micro cracks were constructed. The distribution analysis of internal stresses in the metal under cyclic loading was carried out using the microhardness tester of PMT-3 type.Findings. On the basis of fatigue curves for high-carbon steels analysis the positions of borders dividing the areas of convertible and irreversible damages were determined. The article shows that with the growth of carbon concentration in the steel at invariability of the structural state an increase of fatigue limit is observed. At the same time the acceleration of processes, which determine transition terms from the stage of forming of submicrocracks to the microcracks occurs. The research of microhardness distribution in the metal after destruction confirmed the nature of carbon amount influence on the carbon steel characteristics. Originality. Regardless on the stages of breakdown site forming the carbon steels behavior at a fatigue is determined by the ration between the processes of strengthening and softening. At a cyclic loading the heterogeneity of internal stresses distribution decreases with the increase of distance from the destruction surface. Analysis of metal internal restructuring processes at fatigue loading made it possible to determine that at the stages prior to incubation period in the metal microvolumes the cells are already

  19. Lipoxygenase is irreversibly inactivated by the hydroperoxides formed from the enynoic analogues of linoleic acid

    NARCIS (Netherlands)

    Vliegenthart, J.F.G.; Nieuwenhuizen, W.F.; Kerk-van Hoof, A. van der; Lenthe, J.H. van; Schaik, R.C. van; Versluis, K.; Veldink, G.A.

    1997-01-01

    Triple bond analogues of natural fatty acids irreversibly inactivate lipoxygenase during their enzymatic conversion [Nieuwenhuizen, W. F., et al. (1995) Biochemistry 34, 10538-10545]. To gain insight into the mechanism of the irreversible inactivation of soybean lipoxygenase-1, we studied the enzyma

  20. A minimal dissipation type-based classification in irreversible thermodynamics and microeconomics

    Science.gov (United States)

    Tsirlin, A. M.; Kazakov, V.; Kolinko, N. A.

    2003-10-01

    We formulate the problem of finding classes of kinetic dependencies in irreversible thermodynamic and microeconomic systems for which minimal dissipation processes belong to the same type. We show that this problem is an inverse optimal control problem and solve it. The commonality of this problem in irreversible thermodynamics and microeconomics is emphasized.

  1. A Minimal Dissipation Type-Based Classification in Irreversible Thermodynamics and Microeconomics

    OpenAIRE

    A. M. Tsirlin; Valdimir Kazakov; N. A. Kolinko

    2003-01-01

    We formulate the problem of finding classes of kinetic dependencies in irreversible thermodynamic and microeconomic systems for which minimal dissipation processes belong to the same type. We show that this problem is an inverse optimal control problem and solve it. The commonality of this problem in irreversible thermodynamics and microeconomics is emphasized.

  2. Reversibility and irreversibility from an initial value formulation

    Energy Technology Data Exchange (ETDEWEB)

    Muriel, A., E-mail: amadormuriel@fas.harvard.edu

    2013-07-15

    From a time evolution equation for the single particle distribution function derived from the N-particle distribution function (A. Muriel, M. Dresden, Physica D 101 (1997) 297), an exact solution for the 3D Navier–Stokes equation – an old problem – has been found (A. Muriel, Results Phys. 1 (2011) 2). In this Letter, a second exact conclusion from the above-mentioned work is presented. We analyze the time symmetry properties of a formal, exact solution for the single-particle distribution function contracted from the many-body Liouville equation. This analysis must be done because group theoretic results on time reversal symmetry of the full Liouville equation (E.C.G. Sudarshan, N. Mukunda, Classical Mechanics: A Modern Perspective, Wiley, 1974). no longer applies automatically to the single particle distribution function contracted from the formal solution of the N-body Liouville equation. We find the following result: if the initial momentum distribution is even in the momentum, the single particle distribution is reversible. If there is any asymmetry in the initial momentum distribution, no matter how small, the system is irreversible.

  3. Fuel starvation. Irreversible degradation mechanisms in PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Rangel, Carmen M.; Silva, R.A.; Travassos, M.A.; Paiva, T.I.; Fernandes, V.R. [LNEG, National Laboratory for Energy and Geology, Lisboa (Portugal). UPCH Fuel Cells and Hydrogen Unit

    2010-07-01

    PEM fuel cell operates under very aggressive conditions in both anode and cathode. Failure modes and mechanism in PEM fuel cells include those related to thermal, chemical or mechanical issues that may constrain stability, power and lifetime. In this work, the case of fuel starvation is examined. The anode potential may rise to levels compatible with the oxidization of water. If water is not available, oxidation of the carbon support will accelerate catalyst sintering. Diagnostics methods used for in-situ and ex-situ analysis of PEM fuel cells are selected in order to better categorize irreversible changes of the cell. Electrochemical Impedance Spectroscopy (EIS) is found instrumental in the identification of fuel cell flooding conditions and membrane dehydration associated to mass transport limitations / reactant starvation and protonic conductivity decrease, respectively. Furthermore, it indicates that water electrolysis might happen at the anode. Cross sections of the membrane catalyst and gas diffusion layers examined by scanning electron microscopy indicate electrode thickness reduction as a result of reactions taking place during hydrogen starvation. Catalyst particles are found to migrate outwards and located on carbon backings. Membrane degradation in fuel cell environment is analyzed in terms of the mechanism for fluoride release which is considered an early predictor of membrane degradation. (orig.)

  4. Use of irreversible electroporation in unresectable pancreatic cancer.

    Science.gov (United States)

    Martin, Robert C G

    2015-06-01

    Irreversible electroporation is a non-thermal injury ablative modality that has been in clinical use since 2008 in the treatment of locally advanced soft tissue tumors. It has been reported to be utilized intraoperatively, laparoscopically or percutaneously. The method of action of IRE relies on a high voltage (maximum 3,000 volts) small microsecond pulse lengths (70 to 90 microseconds) to induce cell membrane porosity which leads to slow/protracted cell death over time. One of the largest unmet needs in oncology that IRE has been utilized is in locally advanced (stage III) pancreatic cancer. Recent studies have demonstrated the safety and palliation with encouraging improvement in overall survival. Its inherent limitation still remains tissue heterogeneity and the unique settings based on tumor histology and prior induction therapy. There remains a high technical demand of the end-user and the more extensive knowledge transfer which makes the learning curve longer in order to achieve appropriate and safe utilization. PMID:26151062

  5. Alkylating derivatives of oxotremorine have irreversible actions on muscarinic receptors

    International Nuclear Information System (INIS)

    The authors describe some irreversible muscarinic receptor binding characteristics of BM 123 and MB 130, as well as the persistent inhibitory effect of BM 123 on acetylcholine release from the myenteric plexus of the ginea pig ileum. Binding assays were run on homogenates of the cerebral cortex and heart from male Sprague Dawley rate and the longitudinal muscle of the ileum from male guinea pigs. The minced hear and ileum were homogenized and the final pellets were frozen and thawed for measurement of specific tritium-30quinuclidinyl benzilate. The pellets from cerebral cortex, ileum, and heart were re-suspended to a concentration representing 10, 20, and 100 mg original wet tissue weight per ml 0.05 M phosphate buffer, respectively. The results of tritium-QNB binding measurements made at a single tritium-ligand concentration of 0.4 nM in homogenates of the rat cerebral cortex and heart and the longitudinal muscle of the guinea pig ileum that had been exposed to the indicated concentrations of BM 123 and BM 130 for 20 min

  6. Parametric optimum design of an irreversible spin quantum refrigeration cycle

    Institute of Scientific and Technical Information of China (English)

    Lin Bi-Hong; Chen Jin-Can

    2005-01-01

    The general performance characteristics of an irreversible quantum refrigeration cycle using many non-interacting spin-1/2 systems as the working substance and consisting of two adiabatic and two isomagnetic field processes are investigated, based on the quantum master equation and semi-group approach. Expressions for several important performance parameters such as the coefficient of performance, cooling rate and power input are derived. By using numerical solutions, the cooling rate of the refrigeration cycle subject to the finite cycle duration is optimized. The maximum cooling rate and the corresponding parameters are calculated numerically. The optimal region of the coefficient of performance and the optimal ranges of the temperatures of the working substance and the times spent on the two isomagnetic field processes are determined. Moreover, the optimal performance of the cycle in the high-temperature limit is also analysed in detail. The results obtained here are further generalized, so that they may be directly used to describe the performance of the quantum refrigeration cycle using spin-J systems as the working substance.

  7. Eutectic solidification as explained by the thermodynamics of irreversible processes

    Directory of Open Access Journals (Sweden)

    W. Wołczyński

    2009-01-01

    Full Text Available The grain size diameter is the main parameter characterizing a given metallic alloy. In the case of Al-Si or Fe-C eutectic alloy theaverage inter-lamellar spacing is a good parameter which seems to be adequate to describe this irregular structure. To define the averageinter-lamellar spacing the regular areas within generally irregular structure has been distinguished.It has been postulated that the formation of regular structure could be related to the minimum entropy production criterion. From theother side the maximum destabilization of the non-faceted phase interface could be referred to marginal stability.The criterion of minimum entropy production allows to formulate the growth law for regular lamellar structure solidifying understationary state. It defines the regular eutectic spacing versus growth rate. The marginal stability concept allows to define the maximum wavelength which can be developed at the solid / liquid interface of non-faceted (Al phase. It defines the maximum spacing within irregular structure taking into account the wavelength of instability (marginal stability created at the non-faceted phase interface.An average inter-lamellar spacing results from the relationship formulated on the basis of both spacings. It should beemphasized that both conditions (criteria are deduced from the thermodynamics of irreversible processes.The simplified scheme of irregular structure incorporates, additionally the intermediate lamella of faceted phase that is also taken into account in the definition of average inter-lamellar spacing,

  8. Irreversible electroporation of human primary uveal melanoma in enucleated eyes.

    Directory of Open Access Journals (Sweden)

    Yossi Mandel

    Full Text Available Uveal melanoma (UM is the most common primary intraocular tumor in adults and is characterized by high rates of metastatic disease. Although brachytherapy is the most common globe-sparing treatment option for small- and medium-sized tumors, the treatment is associated with severe adverse reactions and does not lead to increased survival rates as compared to enucleation. The use of irreversible electroporation (IRE for tumor ablation has potential advantages in the treatment of tumors in complex organs such as the eye. Following previous theoretical work, herein we evaluate the use of IRE for uveal tumor ablation in human ex vivo eye model. Enucleated eyes of patients with uveal melanoma were treated with short electric pulses (50-100 µs, 1000-2000 V/cm using a customized electrode design. Tumor bioimpedance was measured before and after treatment and was followed by histopathological evaluation. We found that IRE caused tumor ablation characterized by cell membrane disruption while sparing the non-cellular sclera. Membrane disruption and loss of cellular capacitance were also associated with significant reduction in total tumor impedance and loss of impedance frequency dependence. The effect was more pronounced near the pulsing electrodes and was dependent on time from treatment to fixation. Future studies should further evaluate the potential of IRE as an alternative method of uveal melanoma treatment.

  9. The effects of irreversible electroporation (IRE on nerves.

    Directory of Open Access Journals (Sweden)

    Wei Li

    Full Text Available BACKGROUND: If a critical nerve is circumferentially involved with tumor, radical surgery intended to cure the cancer must sacrifice the nerve. Loss of critical nerves may lead to serious consequences. In spite of the impressive technical advancements in nerve reconstruction, complete recovery and normalization of nerve function is difficult to achieve. Though irreversible electroporation (IRE might be a promising choice to treat tumors near or involved critical nerve, the pathophysiology of the nerve after IRE treatment has not be clearly defined. METHODS: We applied IRE directly to a rat sciatic nerve to study the long term effects of IRE on the nerve. A sequence of 10 square pulses of 3800 V/cm, each 100 µs long was applied directly to rat sciatic nerves. In each animal of group I (IRE the procedure was applied to produce a treated length of about 10 mm. In each animal of group II (Control the electrodes were only applied directly on the sciatic nerve for the same time. Electrophysiological, histological, and functional studies were performed on immediately after and 3 days, 1 week, 3, 5, 7 and 10 weeks following surgery. FINDINGS: Electrophysiological, histological, and functional results show the nerve treated with IRE can attain full recovery after 7 weeks. CONCLUSION: This finding is indicative of the preservation of nerve involving malignant tumors with respect to the application of IRE pulses to ablate tumors completely. In summary, IRE may be a promising treatment tool for any tumor involving nerves.

  10. Irreversible collective migration of cyanobacteria in eutrophic conditions.

    Directory of Open Access Journals (Sweden)

    Julien Dervaux

    Full Text Available In response to natural or anthropocentric pollutions coupled to global climate changes, microorganisms from aquatic environments can suddenly accumulate on water surface. These dense suspensions, known as blooms, are harmful to ecosystems and significantly degrade the quality of water resources. In order to determine the physico-chemical parameters involved in their formation and quantitatively predict their appearance, we successfully reproduced irreversible cyanobacterial blooms in vitro. By combining chemical, biochemical and hydrodynamic evidences, we identify a mechanism, unrelated to the presence of internal gas vesicles, allowing the sudden collective upward migration in test tubes of several cyanobacterial strains (Microcystis aeruginosa PCC 7005, Microcystis aeruginosa PCC 7806 and Synechocystis sp. PCC 6803. The final state consists in a foamy layer of biomass at the air-liquid interface, in which micro-organisms remain alive for weeks, the medium lying below being almost completely depleted of cyanobacteria. These "laboratory blooms" start with the aggregation of cells at high ionic force in cyanobacterial strains that produce anionic extracellular polymeric substances (EPS. Under appropriate conditions of nutrients and light intensity, the high photosynthetic activity within cell clusters leads the dissolved oxygen (DO to supersaturate and to nucleate into bubbles. Trapped within the EPS, these bubbles grow until their buoyancy pulls the biomass towards the free surface. By investigating a wide range of spatially homogeneous environmental conditions (illumination, salinity, cell and nutrient concentration we identify species-dependent thresholds and timescales for bloom formation. We conclude on the relevance of such results for cyanobacterial bloom formation in the environment and we propose an efficient method for biomass harvesting in bioreactors.

  11. Immunologic response to tumor ablation with irreversible electroporation.

    Directory of Open Access Journals (Sweden)

    Xiaoxiang Li

    Full Text Available BACKGROUND: Irreversible electroporation (IRE is a promising technique for the focal treatment of pathologic tissues, which involves placing minimally invasive electrodes within the targeted region. However, the knowledge about the therapeutic efficacy and immune reactions in response to IRE remains in its infancy. METHODS: In this work, to detect whether tumor ablation with IRE could trigger the immunologic response, we developed an osteosarcoma rat model and applied IRE directly to ablate the tumor. In the experiment, 118 SD rats were randomized into 4 groups: the control, sham operation, surgical resection, and IRE groups. Another 28 rats without tumor cell implantation served as the normal non-tumor-bearing group. We analyzed the changes in T lymphocyte subsets, sIL-2R and IL-10 levels in the peripheral blood one day before operation, as well as at 1, 3, 7,14 and 21 days after the operation. Moreover, splenocytes were assayed for IFN-γ and IL-4 production using intracellular cytokine staining one day before the operation, as well as at 7 and 21 days after operation. RESULTS: We found that direct IRE completely ablated the tumor cells. A significant increase in peripheral lymphocytes, especially CD3(+ and CD4(+ cells, as well as an increased ratio of CD4(+/CD8(+ were detectable 7 days after operation in both the IRE and surgical resection groups. Compared with the surgical resection group, the IRE group exhibited a stronger cellular immune response. The sIL-2R level of the peripheral blood in the IRE group decreased with time and was significantly different from that in the surgical resection group. Moreover, ablation with IRE significantly increased the percentage of IFN-γ-positive splenocytes. CONCLUSION: These findings indicated that IRE could not only locally destroy the tumor but also change the status of cellular immunity in osteosarcoma-bearing rats. This provides experimental evidence for the clinical application of IRE in

  12. Fundamental optimal relation of a generalized irreversible Carnot heat pump with complex heat transfer law

    Indian Academy of Sciences (India)

    Jun Li; Lingen Chen; Fengrui Sun

    2010-02-01

    The fundamental optimal relation between heating load and coefficient of performance (COP) of a generalized irreversible Carnot heat pump is derived based on a new generalized heat transfer law, which includes the generalized convective heat transfer law and generalized radiative heat transfer law, $q \\varpropto ( T^{n})^{m}$. The generalized irreversible Carnot heat pump model incorporates several internal and external irreversibilities, such as heat resistance, bypass heat leakage, friction, turbulence and other undesirable irreversibility factors. The added irreversibilities besides heat resistance are characterized by a constant parameter and a constant coefficient. The effects of heat transfer laws and various loss terms are analysed. The heating load vs. COP characteristic of a generalized irreversible Carnot heat pump is a parabolic-like curve, which is consistent with the experimental result of thermoelectric heat pump. The obtained results include those obtained in many literatures and indicated that the analysis results of the generalized irreversible Carnot heat pump were more suitable for engineering practice than those of the endoreversible Carnot heat pump.

  13. Multiscale time irreversibility of heart rate and blood pressure variability during orthostasis

    International Nuclear Information System (INIS)

    Time irreversibility is a characteristic feature of non-equilibrium, complex systems such as the cardiovascular control mediated by the autonomic nervous system (ANS). Time irreversibility analysis of heart rate variability (HRV) and blood pressure variability (BPV) represents a new approach to assess cardiovascular regulatory mechanisms. The aim of this paper was to assess the changes in HRV and BPV irreversibility during the active orthostatic test (a balance of ANS shifted towards sympathetic predominance) in 28 healthy young subjects. We used three different time irreversibility indices—Porta’s, Guzik's and Ehler's indices (P%, G% and E, respectively) derived from data segments containing 1000 beat-to-beat intervals on four timescales. We observed an increase in the HRV and a decrease in the BPV irreversibility during standing compared to the supine position. The postural change in irreversibility was confirmed by surrogate data analysis. The differences were more evident in G% and E than P% and for higher scale factors. Statistical analysis showed a close relationship between G% and E. Contrary to this, the association between P% and G% and P% and E was not proven. We conclude that time irreversibility of beat-to-beat HRV and BPV is significantly altered during orthostasis, implicating involvement of the autonomous nervous system in its generation. (paper)

  14. Cooling load optimization of an irreversible refrigerator with combined heat transfer

    Energy Technology Data Exchange (ETDEWEB)

    El Haj Assad, M. [Aalto University School of Science and Technology, Department of Energy Technology, P. O. Box 14100, 00076 Aalto (Finland)

    2013-07-01

    In this work a mathematical model to study the performance of an irreversible refrigerator has been presented with the consideration of heat exchange by combined convection and radiation. The external irreversibility effects due to finite rate heat transfer as well as the effects of internal dissipations have been considered in the analysis. The relation between the cooling load and the coefficient of performance of the refrigerator has been derived. Furthermore an expression for the maximum cooling rate has been derived. The parameters that affect the cooling load have been investigated. The cooling load has been discussed and the effect of internal irreversibility has been investigated.

  15. A Fingerprint Encryption Scheme Based on Irreversible Function and Secure Authentication

    Science.gov (United States)

    Yu, Jianping; Zhang, Peng; Wang, Shulan

    2015-01-01

    A fingerprint encryption scheme based on irreversible function has been designed in this paper. Since the fingerprint template includes almost the entire information of users' fingerprints, the personal authentication can be determined only by the fingerprint features. This paper proposes an irreversible transforming function (using the improved SHA1 algorithm) to transform the original minutiae which are extracted from the thinned fingerprint image. Then, Chinese remainder theorem is used to obtain the biokey from the integration of the transformed minutiae and the private key. The result shows that the scheme has better performance on security and efficiency comparing with other irreversible function schemes. PMID:25873989

  16. A Fingerprint Encryption Scheme Based on Irreversible Function and Secure Authentication

    Directory of Open Access Journals (Sweden)

    Yijun Yang

    2015-01-01

    Full Text Available A fingerprint encryption scheme based on irreversible function has been designed in this paper. Since the fingerprint template includes almost the entire information of users’ fingerprints, the personal authentication can be determined only by the fingerprint features. This paper proposes an irreversible transforming function (using the improved SHA1 algorithm to transform the original minutiae which are extracted from the thinned fingerprint image. Then, Chinese remainder theorem is used to obtain the biokey from the integration of the transformed minutiae and the private key. The result shows that the scheme has better performance on security and efficiency comparing with other irreversible function schemes.

  17. Cooling load optimization of an irreversible refrigerator with combined heat transfer

    Directory of Open Access Journals (Sweden)

    M. El Haj Assad

    2013-01-01

    Full Text Available In this work a mathematical model to study the performance of an irreversible refrigerator has been presented with the consideration of heat exchange by combined convection and radiation. The external irreversibility effects due to finite rate heat transfer as well as the effects of internal dissipations have been considered in the analysis. The relation between the cooling load and the coefficient of performance of the refrigerator has been derived. Furthermore an expression for the maximum cooling rate has been derived. The parameters that affect the cooling load have been investigated. The cooling load has been discussed and the effect of internal irreversibility has been investigated.

  18. Hematopoiesis stimulation test by interleukin 1{alpha} gene transfer in the Cynomolgus macaque: application to secondary medullary aplasia from an accidental irradiation; Essais de stimulation de l'hematopoiese par le transfert de gene de l'interleukine-1{alpha} chez le macaque cynomolgus: application a l'aplasie medullaire secondaire a une irradiation accidentelle

    Energy Technology Data Exchange (ETDEWEB)

    De Revel, Th.

    2002-12-15

    After a description of the context of medullary aplasia (haematological radiobiology, radiation acute syndrome, therapeutic care), and an overview of knowledge about the interleukin-1 and medullary stroma cells, this research thesis aims at investigating therapeutic alternatives for radio-accidental aplasia. More precisely, it aims at defining means to get cytokines which are efficient for haematopoiesis. Interleukin-1 is chosen for its properties and tests are performed on a macaque with two approaches for gene transfer: an ex vivo transfer by retroviral vector enabling an integration in the target cell genome, and an in situ transfer by adeno-viral vector directly applied in the animal osseous medulla

  19. Treatise on irreversible and statistical thermodynamics an introduction to nonclassical thermodynamics

    CERN Document Server

    Yourgrau, Wolfgang; Raw, Gough

    2002-01-01

    Extensively revised edition of a much-respected work examines thermodynamics of irreversible processes, general principles of statistical thermodynamics, assemblies of noninteracting structureless particles, and statistical theory. 1966 edition.

  20. Cooling Load and COP optimization of an irreversible carnot refrigerator with spin-1/2 systems

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaowie; Chen, Lingen; Sun, Fengrui [College of Naval Architecture and Power, Naval University of Engineering, Wuhan 430033 (China); Wu, Feng [School of Science, Wuhan Institute of Technology, Wuhan 430074 (China); College of Naval Architecture and Power, Naval University of Engineering, Wuhan 430033 (China)

    2011-07-01

    A model of an irreversible quantum refrigerator with working medium consisting of many non-interacting spin-1/2 systems is established in this paper. The quantum refrigeration cycle is composed of two isothermal processes and two irreversible adiabatic processes and is referred to as a spin quantum Carnot refrigeration cycle. Expressions of some important performance parameters, such as cycle period, cooling load and coefficient of performance (COP) for the irreversible spin quantum Carnot refrigerator are derived, and detailed numerical examples are provided. The optimal performance of the quantum refrigerator at high temperature limit is analyzed with numerical examples. Effects of internal irreversibility and heat leakage on the performance are discussed in detail. The endoreversible case, frictionless case and the case without heat leakage are discussed in brief.

  1. Ecological optimization of an irreversible quantum Carnot heat engine with spin-1/2 systems

    International Nuclear Information System (INIS)

    A model of a quantum heat engine with heat resistance, internal irreversibility and heat leakage and many non-interacting spin-1/2 systems is established in this paper. The quantum heat engine cycle is composed of two isothermal processes and two irreversible adiabatic processes and is referred to as a spin quantum Carnot heat engine. Based on the quantum master equation and the semi-group approach, equations of some important performance parameters, such as power output, efficiency, entropy generation rate and ecological function (a criterion representing the optimal compromise between exergy output rate and exergy loss rate), for the irreversible spin quantum Carnot heat engine are derived. The optimal ecological performance of the heat engine in the classical limit is analyzed with numerical examples. The effects of internal irreversibility and heat leakage on ecological performance are discussed in detail.

  2. Cooling load and COP optimization of an irreversible Carnot refrigerator with spin-1/2 systems

    Directory of Open Access Journals (Sweden)

    Xiaowei Liu, Lingen Chen, Feng Wu, Fengrui Sun

    2011-09-01

    Full Text Available A model of an irreversible quantum refrigerator with working medium consisting of many non-interacting spin-1/2 systems is established in this paper. The quantum refrigeration cycle is composed of two isothermal processes and two irreversible adiabatic processes and is referred to as a spin quantum Carnot refrigeration cycle. Expressions of some important performance parameters, such as cycle period, cooling load and coefficient of performance (COP for the irreversible spin quantum Carnot refrigerator are derived, and detailed numerical examples are provided. The optimal performance of the quantum refrigerator at high temperature limit is analyzed with numerical examples. Effects of internal irreversibility and heat leakage on the performance are discussed in detail. The endoreversible case, frictionless case and the case without heat leakage are discussed in brief.

  3. The Effects of Internal and External Irreversibility of a Vapor Compression Refrigeration Cycle

    Science.gov (United States)

    Wang, Fu-Jen; Chiou, Jeng-Shing

    The concept of finite-time thermodynamics is employed to investigate the optimal refrigeration rate for an irreversible refrigeration cycle. The heat transfer between the system (internal) fluid and cooling (external) fluid takes place at the actual heat exchanger, which has the finite-size heat transfer area and the realistic heat transfer effectiveness. The internal irreversibility results from the compression process and the expansion process are also considered. The optimal refrigeration rate is calculated and expressed in terms of the irreversibility parameter (Ir), coefficient of performance (COP), the time ratio(γ) of heat transfer processes and the effectiveness of heat exchanger. The derived COP which consider both the external and internal irreversibility can thus be considered as the benchmark value for a practical refrigeration cycle, and the parametric study can provide the basis for both determination of optimal operating conditions and design of a practical refrigeration cycle.

  4. The maximum coefficient of performance of internally irreversible refrigerators and heat pumps

    Science.gov (United States)

    Ait-Ali, Mohand A.

    1996-04-01

    A class of irreversible refrigeration cycles is investigated to determine the maximum coefficient of performance in the heat pump mode and the refrigerator mode. For the purpose of generality and simplicity of the results, finite-time heat transfer in the condenser and evaporator is expressed in terms of arithmetic mean temperature differences. The generic source of internal irreversibility is measured by a single irreversibility factor which transforms the Clausius inequality into an equality to simplify the cycle model. These optimum cycle performances are obtained as closed form analytical expressions in which the irreversibility factor has been shown to be simply related to the ratio of the actual and endoreversible cycle coefficients of performance.

  5. Irreversible Electroporation of a Hepatocellular Carcinoma Lesion Adjacent to a Transjugular Intrahepatic Portosystemic Shunt Stent Graft

    International Nuclear Information System (INIS)

    We report in a 65-year-old man hepatocellular carcinoma adjacent to a transjugular intrahepatic portosystemic shunt stent-graft which was successfully treated with irreversible electroporation (IRE). IRE is a new non-thermal tissue ablation technique which uses electrical pulses to induce cell necrosis by irreversible membrane poration. IRE proved to be more advantageous in the ablation of perivascular tumor with little injury to the surrounding structures

  6. Irreversible Electroporation of a Hepatocellular Carcinoma Lesion Adjacent to a Transjugular Intrahepatic Portosystemic Shunt Stent Graft

    Energy Technology Data Exchange (ETDEWEB)

    Niessen, Christoph; Jung, Ernst Michael; Wohlgemuth, Walter A. [Department of Radiology, University Medical Center Regensburg, Regensburg D-93053 (Germany); Trabold, Benedikt [Department of Anaesthesia, University Medical Center Regensburg, Regensburg D-93053 (Germany); Haimerl, Michael; Schreyer, Andreas; Stroszczynski, Christian; Wiggermann, Philipp [Department of Radiology, University Medical Center Regensburg, Regensburg D-93053 (Germany)

    2013-07-01

    We report in a 65-year-old man hepatocellular carcinoma adjacent to a transjugular intrahepatic portosystemic shunt stent-graft which was successfully treated with irreversible electroporation (IRE). IRE is a new non-thermal tissue ablation technique which uses electrical pulses to induce cell necrosis by irreversible membrane poration. IRE proved to be more advantageous in the ablation of perivascular tumor with little injury to the surrounding structures.

  7. Maximum power, ecological function and efficiency of an irreversible Carnot cycle. A cost and effectiveness optimization

    OpenAIRE

    Aragon-Gonzalez, G.; Canales-Palma, A.; Leon-Galicia, A.; Morales-Gomez, J. R.

    2007-01-01

    In this work we include, for the Carnot cycle, irreversibilities of linear finite rate of heat transferences between the heat engine and its reservoirs, heat leak between the reservoirs and internal dissipations of the working fluid. A first optimization of the power output, the efficiency and ecological function of an irreversible Carnot cycle, with respect to: internal temperature ratio, time ratio for the heat exchange and the allocation ratio of the heat exchangers; is performed. For the ...

  8. Nature of the irreversibility line in Bi2Sr2CaCu2O8

    International Nuclear Information System (INIS)

    Local vortex dynamics in Bi2Sr2CaCu2O8 single crystals was studied using novel microscopic GaAs/AlGaAs Hall-sensor arrays. The irreversibility line (IL) is found to exist in the absence of bulk pinning. At high temperatures the IL is due to geometrical barriers whereas at intermediate temperatures the irreversible behavior is determined by surface barriers. Bulk pinning governs the IL only at T < 22 K. (orig.)

  9. A review on thermodynamic optimization of irreversible refrigerator and verification with transcritical CO2 system

    OpenAIRE

    Sarkar, Jahar

    2014-01-01

    The transcritical vapor compression refrigeration cycle consists of isothermal heat addition process and isobaric non-isothermal heat rejection process with highly variable heat capacity unlike to the subcritical cycle. Hence, it is quite interesting whether the analysis and optimization results of irreversible Carnot-like refrigerator are applicable for this case. The present study consists of two parts: the detailed review on theoretical analysis and analytical optimizations of irreversible...

  10. Irreversibility analysis for gravity driven non-Newtonian liquid film along an inclined isothermal plate

    International Nuclear Information System (INIS)

    In this paper, the first and second law of thermodynamics are employed in order to study the inherent irreversibility for a gravity driven non-Newtonian Ostwald-de Waele power law liquid film along an inclined isothermal plate. Based on some simplified assumptions, the governing equations are obtained and solved analytically. Expressions for fluid velocity, temperature, volumetric entropy generation numbers, irreversibility distribution ratio and the Bejan number are also determined. (author)

  11. Thermodynamic efficiency of the cardiac cycle and irreversibility in the interbeat interval time series

    OpenAIRE

    Alejandro Muñoz-Diosdado; Gonzalo Gálvez-Coyt; Alejandro Alonso Martínez

    2010-01-01

    Cardiac cycle can be analyzed as a thermodynamic cycle, however, the inherent variability of this cycle implies that, although in the short term the cycle is quasi-reversible, in the long term is irreversible. This work discusses two important aspects of the cardiac cycle related with thermodynamic concepts: the calculation of the cycles efficiency and the quantification of the irreversibility of interbeat interval time series. The results show that there is a variability of cardiac eff...

  12. Thermostability of Irreversible Unfolding alpha-Amylases Analyzed by Unfolded Kinetics

    OpenAIRE

    Duy, C.; Fitter, J.

    2005-01-01

    For most multidomain proteins the thermal unfolding transitions are accompanied by an irreversible step, often related to aggregation at elevated temperatures. As a consequence the analysis of thermostabilities in terms of equilibrium thermodynamics is not applicable, at least not if the irreversible process is fast with respect the structural unfolding transition. In a comparative study we investigated aggregation effects and unfolding kinetics for five homologous alpha-amylases, all from me...

  13. A statistical model for multidimensional irreversible electroporation cell death in tissue

    OpenAIRE

    Rubinsky Boris; Golberg Alex

    2010-01-01

    Abstract Background Irreversible electroporation (IRE) is a minimally invasive tissue ablation technique which utilizes electric pulses delivered by electrodes to a targeted area of tissue to produce high amplitude electric fields, thus inducing irreversible damage to the cell membrane lipid bilayer. An important application of this technique is for cancer tissue ablation. Mathematical modelling is considered important in IRE treatment planning. In the past, IRE mathematical modelling used a ...

  14. Irreversible and reversible topoisomerase II DNA cleavage stimulated by clerocidin: sequence specificity and structural drug determinants.

    Science.gov (United States)

    Binaschi, M; Zagotto, G; Palumbo, M; Zunino, F; Farinosi, R; Capranico, G

    1997-05-01

    In contrast to other topoisomerase II poisons, the microbial terpenoid clerocidin was shown to stimulate irreversible topoisomerase II-mediated DNA cleavage. To establish the structural determinants for drug activity, in this study we have investigated intensity patterns and sequence specificity of clerocidin-stimulated DNA cleavage using 5'-end 32P-labeled DNA fragments. At a majority of the sites, clerocidin-stimulated cleavage did not revert upon NaCl addition; nevertheless, at some sites, cleavage completely reverted. Statistical analyses showed that drug-preferred bases were different in the two cases: guanine and cytosine were highly preferred at position -1 at irreversible and reversible sites, respectively. These results demonstrated that cleavage irreversibility was site selective and required a guanine at the 3' end of the cut. Further experiments revealed that some irreversible sites showed an abnormal electrophoretic mobility in sequencing gels with respect to cleaved bands generated by 4-(9-acridinylamino)methanesulfon-m-anisidide, suggesting a chemical alteration of the DNA strand. Interestingly, the ability to stimulate irreversible cleavage progressively decreased over time when clerocidin was stored in ethanol. Under these conditions, nuclear magnetic resonance measurements demonstrated that the drug underwent structural modifications that involved the C-12-C-15 side chain. Thus, the results indicate that a specific moiety of clerocidin may react with the DNA (guanine at -1) in the ternary complex, resulting in cleavage irreversibility and in altered DNA mobility in sequencing gels. PMID:9135013

  15. The use of TiO2 nanoparticles to reduce refrigerator ir-reversibility

    International Nuclear Information System (INIS)

    Highlights: ► COP of hydrocarbons mixture VCRSs increases less when compared to R134a. ► Compressor ir-reversibility of VCRSs decreases by 33% (R134a), 14% (R436A and R436B). ► Total ir-reversibility of selected VCRSs decreases. ► Exergy efficiency of R134a is exceptionally low at lower reference temperature. ► Exergy efficiency of selected VCRSs increases. - Abstract: The ir-reversibility at the process of a vapour-compression refrigeration system (VCRS) with nanoparticles in the working fluid was investigated experimentally. Mineral oil (MO) with 0.1 g L−1 TiO2 nanoparticles mixture were used as the lubricant instead of Polyol-ester (POE) oil in the R134a, R436A (R290/R600a-56/44-wt.%) and R436B (R290/R600a-52/48-wt.%)VCRSs. The VCRS ir-reversibility at the process with the nanoparticles was investigated using second law of thermodynamics. The results indicate that R134a, R436A and R436B and MO with TiO2 nanoparticles work normally and safely in the VCRS. The VCRSs total ir-reversibility (529, 588 and 570 W) at different process was better than the R134a, R436A and R436B and POE oil system (777, 697 and 683 W). The same tests with Al2O3 nanoparticles showed that the different nanoparticles properties have little effect on the VCRS ir-reversibility. Thus, TiO2 nanoparticles can be used in VCRS with reciprocating compressor to considerably reduce ir-reversibility at the process.

  16. Entransy analyses of heat-work conversion systems with inner irreversible thermodynamic cycles

    Science.gov (United States)

    Cheng, Xue-Tao; Liang, Xin-Gang

    2015-12-01

    In this paper, we try to use the entransy theory to analyze the heat-work conversion systems with inner irreversible thermodynamic cycles. First, the inner irreversible thermodynamic cycles are analyzed. The influences of different inner irreversible factors on entransy loss are discussed. We find that the concept of entransy loss can be used to analyze the inner irreversible thermodynamic cycles. Then, we analyze the common heat-work conversion systems with inner irreversible thermodynamic cycles. As an example, the heat-work conversion system in which the working fluid of the thermodynamic cycles is heated and cooled by streams is analyzed. Our analyses show that larger entransy loss leads to larger output work when the total heat flow from the high temperature heat source and the corresponding equivalent temperature are fixed. Some numerical cases are presented, and the results verify the theoretical analyses. On the other hand, it is also found that larger entransy loss does not always lead to larger output work when the preconditions are not satisfied. Project supported by the National Natural Science Foundation of China (Grant Nos. 51376101 and 51356001).

  17. Inequalities for trace anomalies, length of the RG flow, distance between the fixed points and irreversibility

    CERN Document Server

    Anselmi, D

    2004-01-01

    I argue that in quantum field theory: i) the scheme-invariant area Delta(a') of the graph of the effective beta function between the fixed points defines the length of the RG flow; ii) the minimum of Delta(a') in the space of flows connecting the same UV and IR fixed points defines the (oriented) distance between the fixed points; iii) in even dimensions, the distance between the fixed points is equal to Delta(a)=a_UV-a_IR. These statements imply, in even dimensions, the inequalities 0 =< Delta(a) =< Delta(a'), the irreversibility of the RG flow and the inequality a =< c for free scalars and fermions (but not vectors). I elaborate the axiomatic set-up of irreversibility, based on the notion of oriented distance and the "oriented-triangle inequalities". I show that these axioms imply the irreversibility of the RG flow without a global "a" function. I argue that the RG flow is irreversible in odd dimensions (without a global "a" function) and, in support of this, I check the axioms of irreversibility i...

  18. Irreversible compressible work and available potential energy dissipation in turbulent stratified fluids

    International Nuclear Information System (INIS)

    Although it plays a key role in the theory of stratified turbulence, the concept of available potential energy (APE) dissipation has remained until now a rather mysterious quantity, owing to the lack of rigorous result about its irreversible character or energy conversion type. Here, we show by using rigorous energetics considerations rooted in the analysis of the Navier–Stokes for a fully compressible fluid with a nonlinear equation of state that the APE dissipation is an irreversible energy conversion that dissipates kinetic energy into internal energy, exactly as viscous dissipation. These results are established by showing that APE dissipation contributes to the irreversible production of entropy, and by showing that it is a part of the work of expansion/contraction. Our results provide a new interpretation of the entropy budget, that leads to a new exact definition of turbulent effective diffusivity, which generalizes the Osborn–Cox model, as well as a rigorous decomposition of the work of expansion/contraction into reversible and irreversible components. In the context of turbulent mixing associated with parallel shear flow instability, our results suggests that there is no irreversible transfer of horizontal momentum into vertical momentum, as seems to be required when compressible effects are neglected, with potential consequences for the parameterizations of momentum dissipation in the coarse-grained Navier–Stokes equations. (paper)

  19. Partial purification of the mu opioid receptor irreversibly labeled with [3H]b-funaltrexamine

    International Nuclear Information System (INIS)

    The mu opioid receptor in bovine striatal membranes was specifically and irreversibly labeled by incubation with 5 nM [3H]β-funaltrexamine (approx.-FNA) at 370C for 90 min in the presence of 100 mM NaCl. The specific and irreversible binding of [3H]β-FNA as defined by that blocked by 1 +M naloxone was about 60% of total irreversible binding. The specific irreversible binding was saturable, stereospecific, time-, temperature, and tissue-dependent. Mu opioid ligands were much more potent than delta or kappa ligands in inhibiting the specific irreversible labeling. SDS polyacrylamide gel electrophoresis of solubilized membranes in the presence of 2-mercaptoethanol yielded a major radiolabeled broad band of MW 68-97K daltons, characteristic of a glycoprotein band. This band was not observed in membranes labeled in the presence of excess unlabeled naloxone. The glycoprotein nature of the [3H]β-FNA-labeled opioid receptor was confirmed by its binding to a wheat germ agglutinin-Sepharose column and its elution with N-acetylglucosamine

  20. Osteomielitis por salmonella

    Directory of Open Access Journals (Sweden)

    Alicia Velázquez Pérez

    2014-08-01

    Full Text Available Se presenta el caso de una paciente femenina de color blanco y dos años de edad, con diagnóstico prenatal de sicklemia, que desde edades tempranas tiene problemas de la enfermedad. Ingresó en esta ocasión por una de las complicaciones infecciosas que ocasiona este padecimiento, una osteomielitis del húmero izquierdo, aislándose el germen en el hemocultivo realizado, una salmonella. Necesitó de tratamiento enérgico y prolongado; se obtuvo un resultado satisfactorio en la evolución de la enfermedad y se sigue sistemáticamente por consulta externa en la actualidad

  1. tirados por tractores

    Directory of Open Access Journals (Sweden)

    Ciro E. Iglesias Coronel

    2006-01-01

    Full Text Available En el presente trabajo se brinda la metodología de realización y evaluación de los principales indicadores energéticos de los agregados de transporte agrícola, formados por tractores y remolques con el uso de la tensometría como herramienta para la toma de los datos experimentales de campo.

  2. Irreversible models with Boltzmann–Gibbs probability distribution and entropy production

    International Nuclear Information System (INIS)

    We analyze irreversible interacting spin models evolving according to a master equation with spin flip transition rates that do not obey detailed balance but obey global balance with a Boltzmann–Gibbs probability distribution. Spin flip transition rates with up–down symmetry are obtained for a linear chain, a square lattice, and a cubic lattice with a stationary state corresponding to the Ising model with nearest neighbor interactions. We show that these irreversible dynamics describes the contact of the system with particle reservoirs that cause a flux of particles through the system. Using a microscopic definition, we determine the entropy production rate of these irreversible models and show that it can be written as a macroscopic bilinear form in the forces and fluxes. Exact expressions for this property are obtained for the linear chain and the square lattice. In this last case the entropy production rate displays a singularity at the phase transition point of the same type as the entropy itself

  3. Performance Optimization of Generalized Irreversible Refrigerator Based on a New Ecological Criterion

    Directory of Open Access Journals (Sweden)

    Jie Xu

    2013-11-01

    Full Text Available On the basis of the exergy analysis, a performance optimization is carried out for a generalized irreversible refrigerator model, which takes into account the heat resistance, heat leakage and internal irreversibility losses. A new ecological criterion, named coefficient of performance of exergy (COPE, defined as the dimensionless ratio of the exergy output rate to the exergy loss rate, is proposed as an objective function in this paper. The optimal performance factors which maximize the ecological objective function have been discussed. Numerical examples are given to explain the influences of heat leakage and internal irreversibility on the generalized and optimal performances. This new ecological criterion may be beneficial for determining the reasonable design of refrigerators.

  4. Simplification of irreversible Markov chains by removal of states with fast leaving rates.

    Science.gov (United States)

    Jia, Chen

    2016-07-01

    In the recent work of Ullah et al. (2012a), the authors developed an effective method to simplify reversible Markov chains by removal of states with low equilibrium occupancies. In this paper, we extend this result to irreversible Markov chains. We show that an irreversible chain can be simplified by removal of states with fast leaving rates. Moreover, we reveal that the irreversibility of the chain will always decrease after model simplification. This suggests that although model simplification can retain almost all the dynamic information of the chain, it will lose some thermodynamic information as a trade-off. Examples from biology are also given to illustrate the main results of this paper. PMID:27067245

  5. Mechanism for membrane electroporation irreversibility under high-intensity, ultrashort electrical pulse conditions

    Science.gov (United States)

    Joshi, R. P.; Schoenbach, K. H.

    2002-11-01

    An improved electroporation model is used to address membrane irreversibility under ultrashort electric pulse conditions. It is shown that membranes can survive a strong electric pulse and recover provided the pore distribution has a relatively large spread. If, however, the population consists predominantly of larger radii pores, then irreversibility can result. Physically, such a distribution could arise if pores at adjacent sites coalesce. The requirement of close proximity among the pore sites is more easily satisfied in smaller organelles than in outer cell membranes. Model predictions are in keeping with recent observations of cell damage to intracellular organelles (e.g., mitochondria), without irreversible shock at the outer membranes, by a nanosecond, high-intensity electric pulse. This mechanism also explains the greater damage from multiple electric shocks.

  6. EXERGY-BASED ECOLOGICAL ANALYSIS OF GENERALIZED IRREVERSIBLE HEAT PUMP SYSTEM

    Directory of Open Access Journals (Sweden)

    GOVIND MAHESHWARI

    2011-10-01

    Full Text Available A reverse Carnot cycle forms the basis of all heat-pump cycles in providing heating and cooling loads. The optimal exergy-based Ecological analysis of an irreversible Heat-pump system with the losses of heat resistance, heat leak and internal irreversibility has been carried out by taking into account Exergy based ecological function (E as an objective in the viewpoint of Finite-Time-Thermodynamics (FTT or Entropy Generation Minimization (EGM. Exergy is defined here as the power required minus the lost power. The effects of irreversibilities along with internal heat leakage on coefficient on the performance of the system are investigated. The exergy based Ecological function decreases steadily with irreversibilites and heat leakages in the system. COP in such a system increases with the cycle temperature ratio. If a heat pump cycle is optimized with above mentioned criterion, there is a trade-off between its coefficient of Performance and the heating load it provides.

  7. Thermo-economic modeling and optimization of an irreversible solar-driven heat engine

    International Nuclear Information System (INIS)

    Highlights: • An irreversible solar-driven heat engine is optimized. • Developed multi objective evolutionary approaches is used. • Power output, ecological function and thermal efficiency are optimized. - Abstract: The present paper illustrates a new thermo-economic performance analysis of an irreversible solar-driven heat engine. Moreover, aforementioned irreversible solar-driven heat engine is optimized by employing thermo-economic functions. With the help of the first and second laws of thermodynamics, an equivalent system is initially specified. To assess this goal, three objective functions that the normalized objective function associated to the power output (FP) and Normalized ecological function (FE) and thermal efficiency (ηth) are involved in optimization process simultaneously. Three objective functions are maximized at the same time. A multi objective evolutionary approaches (MOEAs) on the basis of NSGA-II method is employed in this work

  8. Maximum power, ecological function and efficiency of an irreversible Carnot cycle. A cost and effectiveness optimization

    CERN Document Server

    Aragon-Gonzalez, G; Leon-Galicia, A; Morales-Gomez, J R

    2007-01-01

    In this work we include, for the Carnot cycle, irreversibilities of linear finite rate of heat transferences between the heat engine and its reservoirs, heat leak between the reservoirs and internal dissipations of the working fluid. A first optimization of the power output, the efficiency and ecological function of an irreversible Carnot cycle, with respect to: internal temperature ratio, time ratio for the heat exchange and the allocation ratio of the heat exchangers; is performed. For the second and third optimizations, the optimum values for the time ratio and internal temperature ratio are substituted into the equation of power and, then, the optimizations with respect to the cost and effectiveness ratio of the heat exchangers are performed. Finally, a criterion of partial optimization for the class of irreversible Carnot engines is herein presented.

  9. Optimal fundamental characteristic of a quantum harmonic oscillator Carnot refrigerator with multi-irreversibilities

    Directory of Open Access Journals (Sweden)

    Xiaowei Liu, Lingen Chen, Feng Wu, Fengrui Sun

    2015-01-01

    Full Text Available The optimal performance of an irreversible quantum Carnot refrigerator with working medium consisting of many non-interacting harmonic oscillators is investigated in this paper. The quantum refrigerator cycle is composed of two isothermal processes and two irreversible adiabatic processes, and the irreversibilities of heat resistance, internal friction and bypass heat leakage are considered. By using the quantum master equation, semi-group approach and finite time thermodynamics (FTT, this paper derives the cooling load and coefficient of performance (COP of the quantum refrigeration cycle and provides detailed numerical examples. At high temperature limit, the cooling load versus COP characteristic curves are plotted, and effects of internal friction and bypass heat leakage on the optimal performance of the quantum refrigerator are discussed. Three special cases, i.e., endoreversible, frictionless and without bypass heat leakage, are discussed in brief.

  10. Optimization of the performance characteristics in an irreversible regeneration magnetic Brayton refrigeration cycle

    Science.gov (United States)

    Wang, Hao; Wu, GuoXing

    2012-02-01

    A model of the irreversible regenerative Brayton refrigeration cycle working with paramagnetic materials is established, in which the regeneration problem in two constant-magnetic field processes and the irreversibility in two adiabatic processes are considered synthetically. Expressions for the COP, cooling rate, power input, the minimum ratio of the two magnetic fields, etc., are derived. It is found that the influence of the irreversibility and the regeneration on the main performance parameters of the magnetic Brayton refrigerator is remarkable. It is important that we have obtained several optimal criteria, which may provide some theoretical basis for the optimal design and operation of the Brayton refrigerator. The results obtained in the paper can provide some new theoretical information for the optimal design and performance improvement of real Brayton refrigerators.

  11. Reconsideration of Criteria and Modeling in Order to Optimize the Efficiency of Irreversible Thermomechanical Heat Engines

    Directory of Open Access Journals (Sweden)

    Michel Feidt

    2010-12-01

    Full Text Available The purpose of this work is to precise and complete one recently proposed in the literature and relative to a general criterion to maximize the first law efficiency of irreversible heat engines. It is shown that the previous proposal seems to be a particular case. A new proposal has been developed for a Carnot irreversible thermomechanical heat engine at steady state associated to two infinite heat reservoirs (hot source, and cold sink: this constitutes the studied system. The presence of heat leak is accounted for, with the most simple form, as is done generally in the literature. Irreversibility is modeled through , created internal entropy rate in the converter (engine, and , total created entropy rate in the system. Heat transfer laws are represented as general functions of temperatures. These concepts are particularized to the most common heat transfer law (linear one. Consequences of the proposal are examined; some new analytical results are proposed for efficiencies.

  12. Consequences of irreversibilities on optimal intertemporal CO2 emission policies under uncertainty

    International Nuclear Information System (INIS)

    This paper investigates how irreversibilities affect the optimal intertemporal accumulation of greenhouse gases in the atmosphere under uncertainty. More precisely, the evolution of the future temperature is assumed to follow an Ito-process with the drift provided by greenhouse gas emissions. This paper considers two different kinds of irreversibilities: of emissions (i.e., CO2 once dissolved into the air cannot be collected later) and of stopping. These issues are investigated first (in the tradition of the real option literature) as pure stopping problems and then allowing for a continuous choice of emissions. Implications for global warming are: an irreversible stopping of greenhouse gas emissions is never optimal in a continuous framework and yields in the real option framework a less conservationist stopping rule in which uncertainty increases the stopping threshold (i.e. works against conservation). (author)

  13. Reversible and irreversible sorption of perfluorinated compounds (PFCs) by sediments of an urban reservoir.

    Science.gov (United States)

    Chen, Huiting; Reinhard, Martin; Nguyen, Viet Tung; Gin, Karina Yew-Hoong

    2016-02-01

    Uncertainty about the extent to which contaminant sorption by suspended solids and bed sediments is irreversible is a major impediment for modeling and managing the water quality of surface water resources. This study examined reversible and irreversible sorption of several perfluorinated compounds (PFCs) to bed sediments from an urban reservoir. PFCs investigated include C4, C6, C8, C9 and C10 perfluoroalkanoate homologues (PFBA, PFHxA, PFOA, PFNA and PFDA, respectively) and perfluorooctane and hexane sulfonate (PFOS and PFHxS, respectively). Although sorption branches of the PFOS, PFNA and PFDA isotherms were nearly linear (implying a partitioning-like process), desorption experiments indicated that a fraction of the sorbed PFCs were entrapped and resistant to desorption. The hysteretic desorption branches were approximately linear. Irreversibility increased with chain length and was nearly complete for PFDA (thermodynamic irreversibility index (TII) 0.98). For the weakly sorbing PFOA and PFHxS, sorption was largely reversible. Data suggest that (1) for the strongly sorbing PFCs, e.g. PFNA, PFDA and PFOS, bed sediments acted predominantly as irreversible sinks, (2) aqueous concentrations of the moderately sorbing PFCs (PFOA and PFHxS) are buffered by reversibly sorbing suspended solids, and (3) the short-chain PFCs (PFBA and PFHxA) are not significantly sorbed and therefore not expected to be significantly influenced by sediment transport. Situations in which highly contaminated particles entering relatively clean water bodies, equilibrium is approached from the reverse (desorption) direction. For irreversibly sorbed contaminants field-based K(D) values will be higher than the K(D) values derived from laboratory sorption data obtained from forward sorption experiments. PMID:26521093

  14. Experimental studies on irreversibility of electrostatic adsorption of silica nanoparticles at solid-liquid interface.

    Science.gov (United States)

    Li, Xue; Niitsoo, Olivia; Couzis, Alexander

    2014-04-15

    Adsorption of colloidal nanoparticles (NPs) at solid-liquid interface is a scientifically interesting and technologically important phenomenon due to its fundamental importance in many industrial, environmental, and biological processes, such as wastewater treatment, printing, coating of surfaces, chromatography, papermaking, or biocompatibility. The process is well understood theoretically by the random sequential adsorption (RSA) model, based on the assumption of irreversible adsorption. Irreversible adsorption is defined as a process in which, once adsorbed, a particle can neither desorb, nor to move laterally on the surface. However, published experimental data that verifies the irreversibility of particle adsorption are very limited. In this study, we demonstrate the irreversibility of electrostatically driven nanoparticle adsorption utilizing a carefully selected set of experiments. A simple method was employed by uniquely introducing Ag@SiO2 core/shell NPs to perform exchange adsorptions experiments. Stöber SiO2 NPs with a diameter of 50-80 nm were initially electrostatically adsorbed onto amino-functionalized silicon wafer substrates followed by the subsequent adsorption of Ag@SiO2 NPs. The Ag@SiO2 NPs have the same surface chemistry as the neat SiO2 NPs. For the second step the adsorption time was varied from 1 min to 1 week so as to get a thorough understanding of the process irreversibility. Surface coverage quantification has shown that the surface coverage of the initially adsorbed SiO2 NPs stays the same independent of the duration of the second step adsorption using the Ag@SiO2 core/shell NPs. This observation directly confirms the irreversibility of electrostatic adsorption of NPs. PMID:24559699

  15. Canonical formalism, fundamental equation, and generalized thermomechanics for irreversible fluids with heat transfer

    International Nuclear Information System (INIS)

    A Lagrangian with dissipative (e.g., Onsager's) potentials is constructed for the field description of irreversible heat-conducting fluids, off local equilibrium. Extremum conditions of action yield Clebsch representations of temperature, chemical potential, velocities, and generalized momenta, including a thermal momentum introduced recently [R. L. Selinger and F. R. S. Whitham, Proc. R. Soc. London, Ser. A 302, 1 (1968); S. Sieniutycz and R. S. Berry, Phys. Rev. A 40, 348 (1989)]. The basic question asked is ''To what extent may irreversibility, represented by a given form of the entropy source, influence the analytical form of the conservation laws for the energy and momentum?'' Noether's energy for a fluid with heat flow is obtained, which leads to a fundamental equation and extended Hamiltonian dynamics obeying the second law of thermodynamics. While in the case of the Onsager potentials this energy coincides numerically with the classical energy E, it contains an extra term (vanishing along the path) still contributing to an irreversible evolution. Components of the energy-momentum tensor preserve all terms regarded standardly as ''irreversible'' (heat, tangential stresses, etc.) generalized to the case when thermodynamics includes the state gradients and the so-called thermal phase, which we introduce here. This variable, the Lagrange multiplier of the entropy generation balance, is crucial for consistent treatment of irreversible processes via an action formalism. We conclude with the hypothesis that embedding the first and second laws in the context of the extremal behavior of action under irreversible conditions may imply accretion of an additional term to the classical energy

  16. Effect of heat transfer law on the finite-time exergoeconomic performance of a generalized irreversible carnot heat engine

    Directory of Open Access Journals (Sweden)

    Yi Zhang, Lingeng Chen, Guozhong Chai

    2014-01-01

    Full Text Available The analytical expression for profit rate of a generalized irreversible Carnot heat engine cycle based on a generalized radiative heat transfer law is derived by applying the finite time exergoeconomic method, taking into account several additional irreversibilities, such as heat resistance, heat leakage and other undesirable irreversible factors. The compromise optimization between economics (profit rate and the efficiency was obtained by searching the efficiency at maximum profit rate, which is termed as the finite time exergoeconomic performance bound.

  17. Effect of heat transfer law on the finite-time exergoeconomic performance of a generalized irreversible carnot heat engine

    OpenAIRE

    Yi Zhang, Lingeng Chen, Guozhong Chai

    2014-01-01

    The analytical expression for profit rate of a generalized irreversible Carnot heat engine cycle based on a generalized radiative heat transfer law is derived by applying the finite time exergoeconomic method, taking into account several additional irreversibilities, such as heat resistance, heat leakage and other undesirable irreversible factors. The compromise optimization between economics (profit rate) and the efficiency was obtained by searching the efficiency at maximum profit rate, whi...

  18. The universal power and efficiency characteristics for irreversible reciprocating heat engine cycles

    International Nuclear Information System (INIS)

    The performance of irreversible reciprocating heat engine cycles with heat transfer loss and friction-like term loss is analysed using finite-time thermodynamics. The universal relations between the power output and the compression ratio, between the thermal efficiency and the compression ratio, and the optimal relation between power output and the efficiency of the cycles are derived. Moreover, analysis and optimization of the model were carried out in order to investigate the effect of cycle processes on the performance of the cycle using numerical examples. The results obtained herein include the performance characteristics of irreversible reciprocating Diesel, Otto, Atkinson and Brayton cycles

  19. Irreversibility and the Arrow of Time in a Quenched Quantum System.

    Science.gov (United States)

    Batalhão, T B; Souza, A M; Sarthour, R S; Oliveira, I S; Paternostro, M; Lutz, E; Serra, R M

    2015-11-01

    Irreversibility is one of the most intriguing concepts in physics. While microscopic physical laws are perfectly reversible, macroscopic average behavior has a preferred direction of time. According to the second law of thermodynamics, this arrow of time is associated with a positive mean entropy production. Using a nuclear magnetic resonance setup, we measure the nonequilibrium entropy produced in an isolated spin-1/2 system following fast quenches of an external magnetic field. We experimentally demonstrate that it is equal to the entropic distance, expressed by the Kullback-Leibler divergence, between a microscopic process and its time reversal. Our result addresses the concept of irreversibility from a microscopic quantum standpoint. PMID:26588367

  20. Ecological performance of a generalized irreversible Carnot heat engine with complex heat transfer law

    Directory of Open Access Journals (Sweden)

    Jun Li, Lingen Chen, Fengrui Sun

    2011-01-01

    Full Text Available The optimal ecological performance of a generalized irreversible Carnot heat engine with the losses of heat-resistance, heat leakage and internal irreversibility, in which the transfer between the working fluid and the heat reservoirs obeys a complex heat transfer law, including generalized convective heat transfer law and generalized radiative heat transfer law is derived by taking an ecological optimization criterion as the objective, which consists of maximizing a function representing the best compromise between the power and entropy production rate of the heat engine. The effects of heat transfer laws and various loss terms are analyzed. The obtained results include those obtained in many literatures.

  1. Percutaneous Irreversible Electroporation for Recurrent Thyroid Cancer--A Case Report.

    Science.gov (United States)

    Meijerink, Martijn R; Scheffer, Hester J; de Bree, Remco; Sedee, Robert-Jan

    2015-08-01

    A 74-year-old man presented with a small locoregional, histopathologically proven, fluorodeoxyglucose positron emission tomography/computed tomography-avid recurrence of follicular thyroid carcinoma in the left subglottic space after extensive surgical resection, adjuvant radioactive iodine therapy, and external beam radiation therapy. Because all established focal therapies were contraindicated, percutaneous irreversible electroporation was performed without complications. Follow-up imaging at 7 months showed a small ablation scar without signs for residual vital tumor tissue. Irreversible electroporation may be a viable treatment option for selected cases of recurring head and neck tumors that are unsuitable for other local treatments. PMID:26210244

  2. Eigenvalue analysis of an irreversible random walk with skew detailed balance conditions

    Science.gov (United States)

    Sakai, Yuji; Hukushima, Koji

    2016-04-01

    An irreversible Markov-chain Monte Carlo (MCMC) algorithm with skew detailed balance conditions originally proposed by Turitsyn et al. is extended to general discrete systems on the basis of the Metropolis-Hastings scheme. To evaluate the efficiency of our proposed method, the relaxation dynamics of the slowest mode and the asymptotic variance are studied analytically in a random walk on one dimension. It is found that the performance in irreversible MCMC methods violating the detailed balance condition is improved by appropriately choosing parameters in the algorithm.

  3. Comparative performance analysis of irreversible Dual and Diesel cycles under maximum power conditions

    International Nuclear Information System (INIS)

    In this study, a comparative performance analysis and optimisation based on maximum power and maximum thermal efficiency criteria have been performed for irreversible Dual and Diesel cycles. Optimal performance and design parameters, such as pressure ratio, cut-off ratio and extreme temperature ratio, of the cycles has been derived analytically and compared with each other based on maximum power (MP) and the corresponding thermal efficiency criteria. The effects of the internal irreversibilities of the cycles on overall performance in terms of isentropic efficiencies for the compression and expansion processes are also investigated. The obtained results may provide a general theoretical tool for the optimal design and operation of real engines

  4. Irreversible H2-antagonism of the four isomeric butyl analogues of mifentidine.

    Science.gov (United States)

    Bastiaans, H M; Donetti, A; Kramer, K; Bietti, G; Cereda, E; Dubini, D; Mondini, M; Bast, A; Timmerman, H

    1990-04-01

    It has been hypothesized that bidentate hydrogen bonding plays an important role in the interaction of imidazolylphenylformamidines with the H2-receptor. The present study, in which the degree of pseudo-irreversible H2-antagonism of the four isomeric butyl substituted mifentidine analogues was determined on the spontaneously beating right atrium of the male guinea-pig, lends further support to this hypothesis. In solution the EE/EZ ratio is different for the four isomeric butylated mifentidine analogues. The rank order of the percentage of E,E conformation, which favors a bidentate interaction, of the formamidine moiety parallels the rank order of pseudo-irreversible H2-antagonism. PMID:1973582

  5. Lysine acetylation can generate highly charged enzymes with increased resistance toward irreversible inactivation

    OpenAIRE

    Shaw, Bryan F; Schneider, Gregory F.; Bilgiçer, Başar; Kaufman, George K.; Neveu, John M.; Lane, William S.; Whitelegge, Julian P.; Whitesides, George M.

    2008-01-01

    This paper reports that the acetylation of lysine ε-NH3 + groups of α-amylase—one of the most important hydrolytic enzymes used in industry—produces highly negatively charged variants that are enzymatically active, thermostable, and more resistant than the wild-type enzyme to irreversible inactivation on exposure to denaturing conditions (e.g., 1 h at 90°C in solutions containing 100-mM sodium dodecyl sulfate). Acetylation also protected the enzyme against irreversible inactivation by the ...

  6. The protein irreversible denaturation studied by means of the bending vibrational mode

    Science.gov (United States)

    Mallamace, Domenico; Corsaro, Carmelo; Vasi, Cirino; Vasi, Sebastiano; Dugo, Giacomo; Mallamace, Francesco

    2014-10-01

    We study by means of the infrared bending vibrational mode the microscopic mechanisms that are at the base of protein irreversible denaturation. In particular, we follow the thermal evolution of the Amide I and II vibrational modes of lysozyme residuals from ambient temperature toward the temperature of irreversible unfolding. Our results indicate that the thermal changes of the coupling, by means of the hydrogen bond, between hydration water molecules and the different chemical groups of the protein are the main microscopic mechanisms underlying the unfolding process.

  7. Irreversibility and the Arrow of Time in a Quenched Quantum System

    Science.gov (United States)

    Batalhão, T. B.; Souza, A. M.; Sarthour, R. S.; Oliveira, I. S.; Paternostro, M.; Lutz, E.; Serra, R. M.

    2015-11-01

    Irreversibility is one of the most intriguing concepts in physics. While microscopic physical laws are perfectly reversible, macroscopic average behavior has a preferred direction of time. According to the second law of thermodynamics, this arrow of time is associated with a positive mean entropy production. Using a nuclear magnetic resonance setup, we measure the nonequilibrium entropy produced in an isolated spin-1 /2 system following fast quenches of an external magnetic field. We experimentally demonstrate that it is equal to the entropic distance, expressed by the Kullback-Leibler divergence, between a microscopic process and its time reversal. Our result addresses the concept of irreversibility from a microscopic quantum standpoint.

  8. Miotoxicidade por organofosforados

    Directory of Open Access Journals (Sweden)

    Cavaliere Maria J.

    1996-01-01

    Full Text Available Os organofosforados são um grupo de compostos químicos amplamente utilizados em agropecuária como inseticidas, ocasionando intoxicações acidentais em animais e humanos, e mesmo sendo utilizados em tentativas de suicídio. A toxicidade desses produtos decorre sobretudo de insuficiência cárdio-respiratória por compromentimento do sistema nervoso autônomo. Sabe-se que alguns destes compostos induzem em animais de experimentação e em humanos, uma miopatia caracterizada por degeneração de células musculares, comprometendo sobretudo a musculatura respiratória. Baseado no fato de que este comprometimento contribui para a piora da função respiratória, propõe-se um protocolo de avaliação rotineira de miotoxicidade por compostos organofosforados, através de uma bateria mínima e suficiente de colorações e reações histoquímicas para quantificação da necrose muscular. Utilizaram-se como modelo experimental, grupos de ratos albinos (Wistar intoxicados com o organofosforado paraoxon, com e sem antídotos (atropina ou pralidoxima. Verificou-se nos grupos tratados com paraoxon e paraoxon mais atropina, necrose de fibras musculares no diafragma, que atingia em determinadas áreas até 15% das fibras. No grupo tratado com paraoxon mais pralidoxima, a necrose foi mínima, evidenciando o papel mioprotetor deste último antídoto.

  9. Nucleotomia por laser

    OpenAIRE

    Cabral, oão José Lobato Guimarães Ferreira

    2009-01-01

    A hérnia de disco intervertebral com compressão nervosa que não cede ao tratamento médico, tradicionalmente, é indicação para tratamento cirúrgico. No entanto, técnicas minimamente invasivas e os procedimentos percutâneos têm sido usados e desenvolvidos nas últimas duas décadas, tanto como procedimentos alternativos, bem como possibilidades terapêuticas que antecedem o tratamento cirúrgico convencional, podendo adiar o mesmo por tempo indeterminado. De entre estas opções técnicas, surge a Nuc...

  10. Por mil devaluados pesos

    Directory of Open Access Journals (Sweden)

    Annie Rodríguez Collázos

    2013-03-01

    Full Text Available El estudio de lo popular y lo urbano hasta ahora se ha centrado en el comportamiento y en algunas relaciones de los habitantes con su entorno. “Por mil devaluados pesos. Publicidad popular y urbana”, pretende explorar las formas de publicidad, dispersas en diferentes espacios populares y urbanos en Bogotá, identificando esquemas y formas características de sus propios códigos comunicativos; se centran en un objeto de estudio consistente en las estrategias publicitarias y los códigos comunicativos en los mensajes publicitarios populares en las subculturas de San Victorino, 7 de Agosto y Sanandresito de San José.

  11. Superpositions in Prigogine's approach to irreversibility for physical and financial applications

    OpenAIRE

    Carfi', David

    2008-01-01

    In this paper we apply the theory of superpositions for Radon measures on compact subsets of the real Euclidean n-space Rn to Prigogine's approach in the study of irreversible processes, which emerge in physics and in economics, showing that the superposition is a natural rigorous tool feasible to face the problem.

  12. Relativistic thermodynamics of irreversible processes I. Heat conduction, diffusion, viscous flow and chemical reactions; formal part

    NARCIS (Netherlands)

    Kluitenberg, G.A.; Groot, S.R. de; Mazur, P.

    1953-01-01

    The relativistic thermodynamics of irreversible processes is developed for an isotropic mixture in which heat conduction, diffusion, viscous flow, chemical reactions and their cross-phenomena may occur. The four-vectors, representing the relative flows of matter, are defined in such a way that, in t

  13. Pulpitis irreversible como forma de presentación de un odontoma

    OpenAIRE

    Berástegui, Esther; Buenechea Imaz, Ramón

    1997-01-01

    Se presenta un caso de odontoma compuesto que provocó pulpitis irreversible en el incisivo central superior derecho (1,1) en una joven de 20 años. El tratamiento fue la biopulpectomía total y extirpación quirúrgica del tumor.

  14. Revisiting the Glansdorff–Prigogine criterion for stability within irreversible thermodynamics

    Czech Academy of Sciences Publication Activity Database

    Maes, C.; Netočný, Karel

    2015-01-01

    Roč. 159, č. 6 (2015), s. 1286-1299. ISSN 0022-4715 R&D Projects: GA ČR GAP204/12/0897 Institutional support: RVO:68378271 Keywords : irreversible processes * thermodynamic stability * excess entropy production * nonequilibrium free energy * Clausius heat theorem Subject RIV: BE - Theoretical Physics Impact factor: 1.202, year: 2014

  15. Irreversibility and multiplicity: two criteria for the disposal of nuclear wastes

    International Nuclear Information System (INIS)

    Two criteria are suggested for comparing waste management methods: technical irreversibility and site multiplicity. These criteria can be used to reduce future risk in the face of inherent uncertainty and to provide for safe disposal without requiring guaranteed future ability to recognize, detect or repair areas of failure

  16. Unifying principles of irreversibility minimization for efficiency maximization in steady-flow chemically-reactive engines

    International Nuclear Information System (INIS)

    Systems research has led to the conception and development of various steady-flow, chemically-reactive, engine cycles for stationary power generation and propulsion. However, the question that remains unanswered is: What is the maximum-efficiency steady-flow chemically-reactive engine architecture permitted by physics? On the one hand the search for higher-efficiency cycles continues, often involving newer processes and devices (fuel cells, carbon separation, etc.); on the other hand the design parameters for existing cycles are continually optimized in response to improvements in device engineering. In this paper we establish that any variation in engine architecture—parametric change or process-sequence change—contributes to an efficiency increase via one of only two possible ways to minimize total irreversibility. These two principles help us unify our understanding from a large number of parametric analyses and cycle-optimization studies for any steady-flow chemically-reactive engine, and set a framework to systematically identify maximum-efficiency engine architectures. - Highlights: • A unified thermodynamic model to study chemically-reactive engine architectures is developed. • All parametric analyses of efficiency are unified by two irreversibility-minimization principles. • Variations in internal energy transfers yield a net work increase that is greater than engine irreversibility reduced. • Variations in external energy transfers yield a net work increase that is lesser than engine irreversibility reduced

  17. How to account for irreversibility in integrated assessment of climate change?

    International Nuclear Information System (INIS)

    How to account for irreversibility in integrated assessment of climate change? This Ph. D. thesis in Economics balances discounting, technical progress and the inertia of existing capital stock against uncertainty and the inertia of socio-economic systems to examine the issue of near term limitations of greenhouse gases emissions. After a general overview in chapter 2, and a more historical presentation of the debates in chapter 3, chapter 4 proceeds to review a large number of integrated assessment models. Chapter 5 introduces a Model on the Dynamics of Inertia and Adaptability of energy systems: DIAM, used to discuss how much previous studies might have overestimated the long term costs of CO2 limitations and underestimated adjustment costs. It shows that, given a target date for atmospheric CO2 concentration stabilisation, a higher inertia implies a lower optimal concentration trajectory. In a sequential decision framework, chapter 6 shows that current uncertainties about which CO2 concentration ceiling would not present dangerous interference with the climate system justifies precautionary action. Finally, chapter 7 uses the irreversibility effect theory to define formally situations of decision under controversy and compare the irreversibility of CO2 accumulation with the irreversibility of investments needed to moderate it. An option value for greenhouse gases emissions limitations is computed. (author)

  18. Ecological optimization and performance study of irreversible Stirling and Ericsson heat engines

    International Nuclear Information System (INIS)

    The concept of finite time thermodynamics is used to determine the ecological function of irreversible Stirling and Ericsson heat engine cycles. The ecological function is defined as the power output minus power loss (irreversibility), which is the ambient temperature times, the entropy generation rate. The ecological function is maximized with respect to cycle temperature ratio and the expressions for the corresponding power output and thermal efficiency are derived at the optimal operating conditions. The effect of different operating parameters, the effectiveness on the hot, cold and the regenerative side heat exchangers, the cycle temperature ratio, heat capacitance ratio and the internal irreversibility parameter on the maximum ecological function are studied. It is found that the effect of regenerator effectiveness is more than the hot and cold side heat exchangers and the effect of the effectiveness on cold side heat exchanger is more than the effectiveness on the hot side heat exchanger on the maximum ecological function. It is also found that the effect of internal irreversibility parameter is more than the other parameters not only on the maximum ecological function but also on the corresponding power output and the thermal efficiency

  19. Use of atomic force microscopy to quantify slip irreversibility in a nickel-base superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Risbet, M.; Feaugas, X.; Guillemer-Neel, C.; Clavel, M

    2003-09-15

    Atomic force microscopy was used to study the evolution of surface deformation during cyclic loading in a nickel-base superalloy. Cyclic slip irreversibility has been investigated using quantitative evaluation of extrusion heights and inter-band spacing. This approach is applied to formulate a microscopic crack initiation law, compared to a classical Manson-Coffin relationship.

  20. Use of atomic force microscopy to quantify slip irreversibility in a nickel-base superalloy

    International Nuclear Information System (INIS)

    Atomic force microscopy was used to study the evolution of surface deformation during cyclic loading in a nickel-base superalloy. Cyclic slip irreversibility has been investigated using quantitative evaluation of extrusion heights and inter-band spacing. This approach is applied to formulate a microscopic crack initiation law, compared to a classical Manson-Coffin relationship

  1. A computational workflow for the design of irreversible inhibitors of protein kinases.

    Science.gov (United States)

    Del Rio, Alberto; Sgobba, Miriam; Parenti, Marco Daniele; Degliesposti, Gianluca; Forestiero, Rosetta; Percivalle, Claudia; Conte, Pier Franco; Freccero, Mauro; Rastelli, Giulio

    2010-03-01

    Design of irreversible inhibitors is an emerging and relatively less explored strategy for the design of protein kinase inhibitors. In this paper, we present a computational workflow that was specifically conceived to assist such design. The workflow takes the form of a multi-step procedure that includes: the creation of a database of already known reversible inhibitors of protein kinases, the selection of the most promising scaffolds that bind one or more desired kinase templates, the modification of the scaffolds by introduction of chemically reactive groups (suitable cysteine traps) and the final evaluation of the reversible and irreversible protein-ligand complexes with molecular dynamics simulations and binding free energy predictions. Most of these steps were automated. In order to prove that this is viable, the workflow was tested on a database of known inhibitors of ERK2, a protein kinase possessing a cysteine in the ATP site. The modeled ERK2-ligand complexes and the values of the estimated binding free energies of the putative ligands provide useful indicators of their aptitude to bind reversibly and irreversibly to the protein kinase. Moreover, the computational data are used to rank the ligands according to their computed binding free energies and their ability to bind specific protein residues in the reversible and irreversible complexes, thereby providing a useful decision-making tool for each step of the design. In this work we present the overall procedure and the first proof of concept results. PMID:20306284

  2. Thermodynamics of Irreversible Processes. Physical Processes in Terrestrial and Aquatic Ecosystems, Transport Processes.

    Science.gov (United States)

    Levin, Michael; Gallucci, V. F.

    These materials were designed to be used by life science students for instruction in the application of physical theory to ecosystem operation. Most modules contain computer programs which are built around a particular application of a physical process. This module describes the application of irreversible thermodynamics to biology. It begins with…

  3. Irreversible thermodynamics of dark energy on the entropy-corrected apparent horizon

    Energy Technology Data Exchange (ETDEWEB)

    Karami, K; Sahraei, N [Department of Physics, University of Kurdistan, Pasdaran Street, Sanandaj (Iran, Islamic Republic of); Jamil, M, E-mail: KKarami@uok.ac.i, E-mail: mjamil@camp.nust.edu.p [Center for Advanced Mathematics and Physics (CAMP), National University of Sciences and Technology (NUST), Islamabad (Pakistan)

    2010-10-15

    We study the irreversible (non-equilibrium) thermodynamics of the Friedmann-Robertson-Walker (FRW) universe containing only dark energy. Using the modified entropy-area relation that is motivated by loop quantum gravity, we calculate the entropy-corrected form of the apparent horizon of the FRW universe.

  4. Chemical introduction of the green fluorescence: imaging of cysteine cathepsins by an irreversibly locked GFP fluorophore.

    Science.gov (United States)

    Frizler, Maxim; Yampolsky, Ilia V; Baranov, Mikhail S; Stirnberg, Marit; Gütschow, Michael

    2013-09-21

    An activity-based probe, containing an irreversibly locked GFP-like fluorophore, was synthesized and evaluated as an inhibitor of human cathepsins and, as exemplified with cathepsin K, it proved to be suitable for ex vivo imaging and quantification of cysteine cathepsins by SDS-PAGE. PMID:23912233

  5. Imaging of irreversible loss of brain function; Bildgebende Verfahren zur Diagnostik des irreversiblen Hirnfunktionsausfalles

    Energy Technology Data Exchange (ETDEWEB)

    Lanfermann, H. [Hannover Medical School (Germany). Inst. of Diagnostic and Interventional Neuroradiology; Schober, O. [University Hospital Muenster (Germany). Dept. of Nuclear Medicine

    2016-01-15

    The updated guidelines for the determination of irreversible loss of brain function include a substantial innovation, i. e., the use of CT angiography as a supplementary technical examination. Adherence to a standardized protocol is the prerequisite for the application of CT angiography. The guidelines for standardized execution of perfusion scintigraphy are unchanged and still valid. Requirements regarding the quality of examining physicians are specified.

  6. Profit rate performance optimization for a generalized irreversible combined refrigeration cycle

    Indian Academy of Sciences (India)

    Kang Ma; Lingen Chen; Fengrui Sun

    2009-10-01

    Finite-time exergoeconomic performance of a Newtonian heat transfer law system generalized irreversible combined refrigeration cycle model with finite-rate heat transfer, heat leakage and internal irreversibility is presented in this paper. The operation of the generalized irreversible combined refrigeration cycle is viewed as a production process with exergy as its output. The performance optimization of the cycle is performed by taking profit as the objective. The optimal profit rate, optimal COP (coefficient of performance), as well as the relation between the optimal profit rate and COP of the cycle are derived. The focus of this paper is to obtain the compromise optimization between economics (profit rate) and the energy utilization factor (COP) for the cycle, by searching the optimum COP at maximum profit rate, which is termed as the finite time exergoeconomic performance bound. Moreover, the effects of various factors, including heat leakage, internal irreversibility and the price ratio, on the profit rate performance of the cycle are analysed by detailed numerical examples.

  7. A Parametric Study Delineating Irreversible Electroporation from Thermal Damage Based on a Minimally Invasive Intracranial Procedure

    OpenAIRE

    Ellis Thomas L; Neal Robert E; Rossmeisl John H; Garcia Paulo A; Davalos Rafael V

    2011-01-01

    Abstract Background Irreversible electroporation (IRE) is a new minimally invasive technique to kill undesirable tissue in a non-thermal manner. In order to maximize the benefits from an IRE procedure, the pulse parameters and electrode configuration must be optimized to achieve complete coverage of the targeted tissue while preventing thermal damage due to excessive Joule heating. M...

  8. Portable exhausters POR-004 SKID B, POR-005 SKID C, POR-006 SKID D storage plan

    International Nuclear Information System (INIS)

    This document provides a storage plan for portable exhausters POR-004 SKID B, POR-005 SKID C, AND POR-006 SKID D. The exhausters will be stored until they are needed by the TWRS (Tank Waste Remediation Systems) Saltwell Pumping Program. The storage plan provides criteria for portable exhauster storage, periodic inspections during storage, and retrieval from storage

  9. Quantum thermodynamics: Microscopic foundations of entropy and of entropy generation by irreversibility

    Directory of Open Access Journals (Sweden)

    Beretta, Gian Paolo

    2008-02-01

    Full Text Available What is the physical significance of entropy? What is the physical origin of irreversibility? Do entropy and irreversibility exist only for complex and macroscopic systems? Most physicists still accept and teach that the rationalization of these fundamental questions is given by Statistical Mechanics. Indeed, for everyday laboratory physics, the mathematical formalism of Statistical Mechanics (canonical and grand-canonical, Boltzmann, Bose-Einstein and Fermi-Dirac distributions allows a successful description of the thermodynamic equilibrium properties of matter, including entropy values. However, as already recognized by Schrodinger in 1936, Statistical Mechanics is impaired by conceptual ambiguities and logical inconsistencies, both in its explanation of the meaning of entropy and in its implications on the concept of state of a system. An alternative theory has been developed by Gyftopoulos, Hatsopoulos and the present author to eliminate these stumbling conceptual blocks while maintaining the mathematical formalism so successful in applications. To resolve both the problem of the meaning of entropy and that of the origin of irreversibility we have built entropy and irreversibility into the laws of microscopic physics. The result is a theory, that we call Quantum Thermodynamics, that has all the necessary features to combine Mechanics and Thermodynamics uniting all the successful results of both theories, eliminating the logical inconsistencies of Statistical Mechanics and the paradoxes on irreversibility, and providing an entirely new perspective on the microscopic origin of irreversibility, nonlinearity (therefore including chaotic behavior and maximal-entropy-generation nonequilibrium dynamics. In this paper we discuss the background and formalism of Quantum Thermodynamics including its nonlinear equation of motion and the main general results. Our objective is to show in a not-too-technical manner that this theory provides indeed a

  10. Using irreversible compression in digital radiology: a preliminary study of the opinions of radiologists

    Science.gov (United States)

    Seeram, Euclid

    2006-03-01

    The large volumes of digital images produced by digital imaging modalities in Radiology have provided the motivation for the development of picture archiving and communication systems (PACS) in an effort to provide an organized mechanism for digital image management. The development of more sophisticated methods of digital image acquisition (Multislice CT and Digital Mammography, for example), as well as the implementation and performance of PACS and Teleradiology systems in a health care environment, have created challenges in the area of image compression with respect to storing and transmitting digital images. Image compression can be reversible (lossless) or irreversible (lossy). While in the former, there is no loss of information, the latter presents concerns since there is a loss of information. This loss of information from diagnostic medical images is of primary concern not only to radiologists, but also to patients and their physicians. In 1997, Goldberg pointed out that "there is growing evidence that lossy compression can be applied without significantly affecting the diagnostic content of images... there is growing consensus in the radiologic community that some forms of lossy compression are acceptable". The purpose of this study was to explore the opinions of expert radiologists, and related professional organizations on the use of irreversible compression in routine practice The opinions of notable radiologists in the US and Canada are varied indicating no consensus of opinion on the use of irreversible compression in primary diagnosis, however, they are generally positive on the notion of the image storage and transmission advantages. Almost all radiologists are concerned with the litigation potential of an incorrect diagnosis based on irreversible compressed images. The survey of several radiology professional and related organizations reveals that no professional practice standards exist for the use of irreversible compression. Currently, the

  11. Multi-objective optimization of an irreversible Stirling cryogenic refrigerator cycle

    International Nuclear Information System (INIS)

    Highlights: • A parametric investigation of irreversible Stirling cryogenic refrigerator cycles is presented. • Both internal and external irreversibilities are included in this study, moreover, heat capacities of external reservoirs are involved. • Multi-objective evolutionary algorithm based on NSGA-II approach is utilized. • Three robust decision making approaches are utilized to determine final optimum solution. - Abstract: The main aim of this research article is a parametric demonstration of irreversible Stirling cryogenic refrigerator cycles that includes irreversibilities such as external and internal irreversibilities. In addition, through this study, finite heat capacities of external reservoirs are considered accordingly. To reach the addressed goal of this research, three objective functions that include the input power of the Stirling refrigerator, the coefficient of performance (COP) and cooling load (RL) have been involved in optimization process simultaneously. The first aforementioned objective function has to minimize; the rest objective functions, on the other hand, have to maximize in parallel optimization process. Developed multi objective evolutionary approaches (MOEAs) based on NSGA-II algorithm is implemented throughout this work. Moreover, cold-side’s effectiveness of the heat exchanger, hot-side’s effectiveness of the heat exchanger, heat source’s heat capacitance rate, heat sink’s capacitance rate, temperature ratio ((Th)/(Tc) ), temperature of cold side are assigned as decision variables for decision making procedure. To gain a robust decision, different decision making approaches that include TOPSIS, LINMAP and fuzzy Bellman–Zadeh are used. Pareto optimal frontier was determined precisely and then three final outputs have been gained by means of the mentioned decision making approaches

  12. Reversible and irreversible electroporation of cell suspensions flowing through a localized DC electric field.

    Science.gov (United States)

    Korohoda, Włodzimierz; Grys, Maciej; Madeja, Zbigniew

    2013-03-01

    Experiments on reversible and irreversible cell electroporation were carried out with an experimental setup based on a standard apparatus for horizontal electrophoresis, a syringe pump with regulated cell suspension flow velocity and a dcEF power supply. Cells in suspension flowing through an orifice in a barrier inserted into the electrophoresis apparatus were exposed to defined localized dcEFs in the range of 0-1000 V/cm for a selected duration in the range 10-1000 ms. This method permitted the determination of the viability of irreversibly electroperforated cells. It also showed that the uptake by reversibly electroperforated cells of fluorescent dyes (calcein, carboxyfluorescein, Alexa Fluor 488 Phalloidin), which otherwise do not penetrate cell membranes, was dependent upon the dcEF strength and duration in any given single electrical field exposure. The method yields reproducible results, makes it easy to load large volumes of cell suspensions with membrane non-penetrating substances, and permits the elimination of irreversibly electroporated cells of diameter greater than desired. The results concur with and elaborate on those in earlier reports on cell electroporation in commercially available electroporators. They proved once more that the observed cell perforation does not depend upon the thermal effects of the electric current upon cells. In addition, the method eliminates many of the limitations of commercial electroporators and disposable electroporation chambers. It permits the optimization of conditions in which reversible and irreversible electroporation are separated. Over 90% of reversibly electroporated cells remain viable after one short (less than 400 ms) exposure to the localized dcEF. Experiments were conducted with the AT-2 cancer prostate cell line, human skin fibroblasts and human red blood cells, but they could be run with suspensions of any cell type. It is postulated that the described method could be useful for many purposes in

  13. [Determination of irreversibility of clinical brain death. Electroencephalography and evoked potentials].

    Science.gov (United States)

    Buchner, H; Ferbert, A

    2016-02-01

    Principally, in the fourth update of the rules for the procedure to finally determine the irreversible cessation of function of the cerebrum, the cerebellum and the brainstem, the importance of an electroencephalogram (EEG), somatosensory evoked potentials (SEP) and brainstem auditory evoked potentials (BAEP) are confirmed. This paper presents the reliability and validity of the electrophysiological diagnosis, discusses the amendments in the fourth version of the guidelines and introduces the practical application, problems and sources of error.An EEG is the best established supplementary diagnostic method for determining the irreversibility of clinical brain death syndrome. It should be noted that residual brain activity can often persist for many hours after the onset of brain death syndrome, particularly in patients with primary brainstem lesions. The derivation and analysis of an EEG requires a high level of expertise to be able to safely distinguish artefacts from primary brain activity. The registration of EEGs to demonstrate the irreversibility of clinical brain death syndrome is extremely time consuming.The BAEPs can only be used to confirm the irreversibility of brain death syndrome in serial examinations or in the rare cases of a sustained wave I or sustained waves I and II. Very often, an investigation cannot be reliably performed because of existing sound conduction disturbances or failure of all potentials even before the onset of clinical brain death syndrome. This explains why BAEPs are only used in exceptional cases.The SEPs of the median nerve can be very reliably derived, are technically simple and with few sources of error. A serial investigation is not required and the time needed for examination is short. For these reasons SEPs are given preference over EEGs and BAEPs for establishing the irreversibility of clinical brain death syndrome. PMID:26785843

  14. Ojo por ojo

    OpenAIRE

    Ramón del Llano Ibáñez

    2011-01-01

    Nuestro pan y café de la mañana se acompaña de noticias alrededor de ejecuciones, de fosas clandestinas, de batallas del ejército, de balaceras en las calles y civiles caídos por balas perdidas : la muerte acompaña nuestro desayuno. Las calaveras de azúcar del día de muertos hoy son calaveras reales y amargas : 40 000 muertos en cuatro años después que el Presidente Calderón declaró la guerra a los narcotraficantes. Se han apresado a varios e importantes miembros de los cárteles : pero han si...

  15. A vida por segundos

    OpenAIRE

    Silva, Pedro Miguel Paiva da

    2010-01-01

    A Enfermagem regista evolução a vários níveis, o que torna imperioso reconhecer como de significativo valor o papel do enfermeiro. A Especialização em Enfermagem Médico-Cirúrgica visa o desenvolvimento de competências para a assistência de Enfermagem avançada ao doente adulto e idoso em estado crítico, revelando uma maior apropriação, por parte dos enfermeiros especialistas de uma concepção de cuidados sustentada numa conceptualização científica dos cuidados, daí infere-se o contributo num...

  16. Ojo por ojo

    Directory of Open Access Journals (Sweden)

    Ramón del Llano Ibáñez

    2011-12-01

    Full Text Available Nuestro pan y café de la mañana se acompaña de noticias alrededor de ejecuciones, de fosas clandestinas, de batallas del ejército, de balaceras en las calles y civiles caídos por balas perdidas : la muerte acompaña nuestro desayuno. Las calaveras de azúcar del día de muertos hoy son calaveras reales y amargas : 40 000 muertos en cuatro años después que el Presidente Calderón declaró la guerra a los narcotraficantes. Se han apresado a varios e importantes miembros de los cárteles : pero han si...

  17. Onicomicosis por hongos fuliginosos

    Directory of Open Access Journals (Sweden)

    Ingrid Salas-Campos

    2009-12-01

    Full Text Available Justificación y objetivo: Las infecciones de las uñas producidas por hongos son un problema de frecuente consulta dermatológica. Los dermatofitos son la mayor causa de estas infecciones, siendo Trichophyton rubrum el agente etiológico más importante. Sin embargo, los hongos no dermatofitos, tanto hialinos como fuliginosos, pueden ser también responsables de estos cuadros clínicos. Debido a que estos hongos tienden a ser resistentes a los antimicóticos comúnmente usados para tratar las onicomicosis, es que se hace indispensable que el clínico se asegure por medio de un examen de laboratorio de la etiología de la infección. Métodos: Se estudiaron tres casos de pacientes con lesiones en uñas, que acudieron al laboratorio de Micología Médica, Facultad de Microbiología, Universidad de Costa Rica. Se realizaron los análisis de rutina para aislamiento e identificación de hongos patógenos. Resultados: En los tres casos estudiados se observó al examen directo micelio fuliginoso. En uno de los casos se aisló e identificó Scytalidium dimidiatum, hongo que presenta resistencia a los antifúngicos utilizados para tratar onicomicosis. Conclusión. El reporte de hongos diferentes a los dermatofitos como agentes etiológicos de onicomicosis es importante para que el médico pueda elegir el tratamiento más recomendado para este tipo de infección.

  18. Lie-Admissible Invariant Origin of Irreversibility for Matter and Antimatter at the Classical and Operator Levels

    CERN Document Server

    Santilli, R M

    2006-01-01

    It was generally believed throughout the 20-th century that irreversibility is a purely classical event without operator counterpart. However, a classical irreversible system cannot be consistently decomposed into a finite number of reversible quantum particles (and, vice versa), thus establishing that the origin of irreversibility is basically unknown at the dawn of the 21-th century. To resolve this problem, we adopt the historical an- alytic representation of irreversibility by Lagrange and Hamilton with external terms in their analytic equations; we show that, when properly written, the brackets of the time evolution characterize covering Lie-admissible algebras; we show that the for- malism has a fully consistent operator counterpart given by the Lie-admissible branch of hadronic mechanics; we identify catastrophic mathematical and physical inconsis- tencies when irreversible formulations are treated with the conventional mathematics used for reversible systems; and show that, when the dynamical equation...

  19. Sociedad por Acciones Simplificada

    Directory of Open Access Journals (Sweden)

    Carlos Andrés Arcila Salazar

    2009-07-01

    Full Text Available En Colombia, aspectos como la responsabilidad limitada; supresión de la llamada doctrina de ultra vires; duración ilimitada; eliminación de la regla, una acción, un voto; remedios al abuso de los derechos; posibilidad de eliminar prohibiciones a los administradores, libertad de establecer restricciones para la transferencia de acciones y la simplificación de los procedimientos de fusión; son inviables bajo nuestra legislación. Sin embargo, la Ley 1258 de 2008, ha incorporado al derecho societario colombiano un nuevo tipo societario híbrido, llamado “Sociedad por Acciones Simplificada”. Esta forma societaria híbrida se basa en un principio básico: garantizar amplia libertad a los empresarios en la estructuración de sus relaciones a través de disposiciones contractuales. La S.A.S. provee a los empresarios significativa flexibilidad contractual, a la vez que preserva beneficios como la limitación de la responsabilidad.

  20. Sociedad por Acciones Simplificada

    Directory of Open Access Journals (Sweden)

    Carlos Andrés Arcila Salazar

    2009-06-01

    Full Text Available En Colombia, aspectos como la responsabilidad limitada; supresión de la llamada doctrina de ultra vires; duración ilimitada; eliminación de la regla, una acción, un voto; remedios al abuso de los derechos; posibilidad de eliminar prohibiciones a los administradores, libertad de establecer restricciones para la transferencia de acciones y la simplificación de los procedimientos de fusión; son inviables bajo nuestra legislación. Sin embargo, la Ley 1258 de 2008, ha incorporado al derecho societario colombiano un nuevo tipo societario híbrido, llamado “Sociedad por Acciones Simplificada”. Esta forma societaria híbrida se basa en un principio básico: garantizar amplia libertad a los empresarios en la estructuración de sus relaciones a través de disposiciones contractuales. La S.A.S. provee a los empresarios significativa flexibilidad contractual, a la vez que preserva beneficios como la limitación de la responsabilidad.

  1. Suppression of irreversible capacity loss in Li-rich layered oxide by fluorine doping

    Science.gov (United States)

    Song, Jay Hyok; Kapylou, Andrei; Choi, Hee Sung; Yu, Byong Yong; Matulevich, Evegeniya; Kang, Sun Ho

    2016-05-01

    Li[Li1/6Ni1/6Co1/6Mn1/2]O2-xFx (x = 0.00 to 0.07) materials were synthesized with low temperature heat treatment (700 °C) and their electrochemical performances were evaluated. With the addition of fluorine, the reversible capacity significantly increased as the irreversibility was suppressed during the first cycle. The reduction of irreversibility was mainly attributed to the enhanced first cycle efficiency of Li2MnO3-like component after the fluorine addition. By combining results of the X-ray diffraction (XRD), secondary ion mass spectrometry (SIMS), In-situ X-ray absorption spectroscopy (XAS) analyses, and first principle calculations, it was proposed that the presence of fluorine facilitated the reduction of cobalt and manganese ions in Li-rich layered oxide, and that the reduced transition metal (TM) ions suppressed structural changes.

  2. Irreversible electrical manipulation of magnetization on BiFeO{sub 3}-based heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qingyu, E-mail: xuqingyu@seu.edu.cn, E-mail: jdu@nju.edu.cn; Xu, Zhenyu [Department of Physics, Southeast University, Nanjing 211189 (China); Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 210096 (China); Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, Suzhou 215123 (China); He, Maocheng; Du, Jun, E-mail: xuqingyu@seu.edu.cn, E-mail: jdu@nju.edu.cn [Department of Physics and National Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093 (China); Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); Cao, Yanqiang [Department of Materials Science and Engineering, Nanjing University, Nanjing 210008 (China)

    2015-05-07

    We prepared several heterostructures, Co/Bi{sub 0.90}La{sub 0.10}FeO{sub 3} on surface oxidized Si or (111) SrTiO{sub 3} and NiFe/Bi{sub 0.90}La{sub 0.10}FeO{sub 3} on (001) SrTiO{sub 3} substrates using LaNiO{sub 3} as bottom electrode. With different strategies of voltage application, the exchange bias field H{sub E} decreased with increasing voltage irreversibly for all the heterostructures at room temperature. The chemical state at the NiFe/Bi{sub 0.90}La{sub 0.10}FeO{sub 3} interface was studied by X-ray photoelectron spectroscopy before and after the electrical manipulation. The oxidization of the metallic ferromagnetic layer at interface after the electrical manipulation has been confirmed, which might explain the irreversibility.

  3. Local Stability Analysis for a Thermo-Economic Irreversible Heat Engine Model under Different Performance Regimes

    Directory of Open Access Journals (Sweden)

    Marco A. Barranco-Jiménez

    2015-12-01

    Full Text Available A recent work reported a local stability analysis of a thermo-economical model of an irreversible heat engine working under maximum power conditions. That work showed that after small perturbations to the working temperatures, the system decreases exponentially to the steady state characterized by two different relaxation times. This work extends the local stability analysis considering other performance regimes: the Maximum Efficient Power (MEP and the Ecological Function (EF regimes. The relaxation time was shown under different performance regimes as functions of the temperature ratio τ = T2/T1, with T1 > T2, the fractional fuel cost f and a lumped parameter R related to the internal irreversibilities degree. Under Maximum Efficient Power conditions the relaxation times are less than the relaxation times under both Maximum Ecological function and Maximum Power. At Maximum Power Efficient conditions, the model gives better stability conditions than for the other two regimes.

  4. Coefficient of performance under optimized figure of merit in minimally nonlinear irreversible refrigerator

    Science.gov (United States)

    Izumida, Y.; Okuda, K.; Calvo Hernández, A.; Roco, J. M. M.

    2013-01-01

    We apply the model of minimally nonlinear irreversible heat engines developed by Izumida and Okuda (EPL, 97 (2012) 10004) to refrigerators. The model assumes extended Onsager relations including a new nonlinear term accounting for dissipation effects. The bounds for the optimized regime under an appropriate figure of merit and the tight-coupling condition are analyzed and successfully compared with those obtained previously for low-dissipation Carnot refrigerators in the finite-time thermodynamics framework. Besides, we study the bounds for the nontight-coupling case numerically. We also introduce a leaky low-dissipation Carnot refrigerator and show that it serves as an example of the minimally nonlinear irreversible refrigerator, by calculating its Onsager coefficients explicitly.

  5. Thermo-economic and thermodynamic analysis and optimization of a two-stage irreversible heat pump

    International Nuclear Information System (INIS)

    Highlights: • Thermodynamic modeling of a two-stage irreversible heat pump is performed. • The latter is achieved using NSGA algorithm and thermodynamic analysis. • 3 answers given by the decision-making methods selected. - Abstract: This research study mainly deals with a comprehensive thermodynamic modeling and thermo-economic optimization of an irreversible absorption heat pump. For the optimization goal, various objective functions are considered comprising the specific heating load, coefficient of performance (COP) and the thermo-economic benchmark (F). In order to specify the optimum design variables, non-dominant sorting genetic algorithm (NSGA) is applied satisfying some restrictions. In this optimization study, all three objective functions (e.g. COP, F and specific heating load) are maximized. In addition, decision making is carried out using three well-suited approaches namely LINAMP and TOPSIS and FUZZY. Finally, sensitivity analysis and error analysis are conducted in order to improve understanding of the system performance

  6. Irreversible Evolution of a Wave Packet in The Rigged Hilbert Space Quantum Mechanics

    CERN Document Server

    Marcucci, Giulia

    2016-01-01

    It is well known that a state with complex energy cannot be the eigenstate of a self-adjoint operator, like the Hamiltonian. Resonances, i.e. states with exponentially decaying observables, are not vectors belonging to the conventional Hilbert space. One can describe these resonances in an unusual mathematical formalism, based on the so-called Rigged Hilbert Space (RHS). In the RHS, the states with complex energy are denoted as Gamow Vectors (GV), and they model decay processes. We study GV of the Reversed Harmonic Oscillator (RHO), and we analytically and numerically investigate the unstable evolution of wave packets. We introduce the background function to study initial data not composed only by a summation of GV and we analyse different wave packets belonging to specific function spaces. Our work furnishes support to the idea that irreversible wave propagations can be investigated by means of Rigged Hilbert Space Quantum Mechanics and provides insights for the experimental investigation of irreversible dyn...

  7. Effects of Detunings on Dynamically Induced Irreversibility in Coherently Driven Systems

    Institute of Scientific and Technical Information of China (English)

    HU Xiang-Ming; PENG Jin-Sheng

    2000-01-01

    Effects of detunings on dynamically induced irreversibilityis studied for coherently driven V systems in which there is no conventional source of irreversible population pumping. For atomic barium (γ1/γ2 = 400 》 1, where γ1 and γ2 are the rates of the spontaneous decay from the excited states 6s6p 1P1 and 6s6p 3p1 to the ground state 6s2 1So, espectively), the strong irreversibility is found to lead to a maximum inversion of 0.77 [only 0.1 in Phys. Rev. Lett. 71 (1993) 4311]. The maximum population inversion requires relatively strong fields coupled respectively to two transitions, a disparity in two atomic decay rates, and the atom-field detunings of opposite signs. However, it is also shown that even in the cases where two detunings have the same sign, or where two decay rates are equal, population inversion takes place.

  8. Irreversible Change of the Pore Structure of ZIF-8 in Carbon Dioxide Capture with Water Coexistence

    DEFF Research Database (Denmark)

    Liu, Huang; Guo, Ping; Regueira Muñiz, Teresa;

    2016-01-01

    showed an irreversible change of its framework, which occurs during the CO2 capture process. It was found that there is an irreversible chemical reaction among ZIF-8, water, and CO2, which creates both zinc carbonate (or zinc carbonate hydroxides) and single 2-methylimidazole crystals, and therefore the......The performance of zeolitic imidazolate framework 8 (ZIF-8) for CO2 capture under three different conditions (wetted ZIF-8, ZIF-8/water slurry, and ZIF-8/water-glycol slurry) was systemically investigated. This investigation included the study of the pore structure stability of ZIF-8 by using X...... pore structure of ZIF-8 collapses. It is suggested therefore that care must be taken when using ZIF-8 or products containing ZIF-8 for gas capture, gas separation, or other applications where both water and acid gases coexist....

  9. Problems of saturation of the excitation and creation of irreversible changes in solid after laser irradiation

    International Nuclear Information System (INIS)

    The problem of modeling of processes of the irreversible interaction light and solid is discussed. This problem is connected with the processes of the saturation the excitation of respective scattering centers. The possible cascades of these processes are analyzed. The correlation between nonequilibrium and irreversible phenomena are analyzed. Two-dimensional sphalerite lattice of InSb was used for the kinetic modeling of the hierarchic processes of saturation of the excitation respective chemical bonds. The cascade characteristics of these processes were estimated for the cylindrical form of 'zone of energy scattering' of photon. The comparative analyses these results with results, which were received with the help straight method and method the spherical form of 'zone of energy scattering' of photon, is represented too. The good concordance of experimental and theoretical data was received. (authors)

  10. Lagrangian formulation of irreversible thermodynamics and the second law of thermodynamics

    International Nuclear Information System (INIS)

    We show that the equations which describe irreversible evolution of a system can be derived from a variational principle. We suggest a Lagrangian, which depends on the properties of the normal and the so-called “mirror-image” system. The Lagrangian is symmetric in time and therefore compatible with microscopic reversibility. The evolution equations in the normal and mirror-imaged systems are decoupled and describe therefore independent irreversible evolution of each of the systems. The second law of thermodynamics follows from a symmetry of the Lagrangian. Entropy increase in the normal system is balanced by the entropy decrease in the mirror-image system, such that there exists an “integral of evolution” which is a constant. The derivation relies on the property of local equilibrium, which states that the local relations between the thermodynamic quantities in non-equilibrium are the same as in equilibrium

  11. Lagrangian formulation of irreversible thermodynamics and the second law of thermodynamics.

    Science.gov (United States)

    Glavatskiy, K S

    2015-05-28

    We show that the equations which describe irreversible evolution of a system can be derived from a variational principle. We suggest a Lagrangian, which depends on the properties of the normal and the so-called "mirror-image" system. The Lagrangian is symmetric in time and therefore compatible with microscopic reversibility. The evolution equations in the normal and mirror-imaged systems are decoupled and describe therefore independent irreversible evolution of each of the systems. The second law of thermodynamics follows from a symmetry of the Lagrangian. Entropy increase in the normal system is balanced by the entropy decrease in the mirror-image system, such that there exists an "integral of evolution" which is a constant. The derivation relies on the property of local equilibrium, which states that the local relations between the thermodynamic quantities in non-equilibrium are the same as in equilibrium. PMID:26026433

  12. Labile phytochrome and photoperiodic flower induction in Pharbitis nil Chois. The irreversible phytochrome hypothesis

    Directory of Open Access Journals (Sweden)

    Mariusz Cymerski

    2014-02-01

    Full Text Available Seedlings of Pharbitis nil cultivated under non-inductive conditions of white light were subjected to generative induction applying one 16-hour-long period of inductive night. During the eighth hour the night was interrupted with 1 min of red light pulse which completely inhibited the flowering. Treating the plants with KCN blocked the inhibiting effect of red light. Because KCN lowers considerably the rate of destruction of labile Pfd in some plant systems, it seems probable that red light night-break irradiation (without KCN, which blocked the flowering, leads also to the accumulation of unknown Pfd destruction products (irreversible phytochrome. It also suggests that it is not the labile PfrI itself but the products of its irreversible transformation that could be active in the photoperiodic control of flowering.

  13. Irreversible and irretrievable commitments of material resources (Revision 1) - June 1976

    International Nuclear Information System (INIS)

    In accordance with 10 CFR Part 51, Licensing and Regulatory Policy and Procedures for Environmental Protection, applicants are required to discuss any irreversible and irretrievable commitments of resources that would be involved in a proposed action, should it be implemented. The construction and operation of nuclear power stations involve commitments of such resources as water, fuel and materials. The guide presented identifies a report on material resources that forms a basis acceptable to the NRC staff for required discussions of irreversible and irretrievable commitments of material resources involved in the construction of a 1000 MWe pressurized water reactor. The guide describes numerical estimates useful in all such discussions. It also provides methods of computation that may be referenced

  14. Optimum criteria of an irreversible quantum Brayton refrigeration cycle with an ideal Bose gas

    International Nuclear Information System (INIS)

    An irreversible cycle model of the quantum Brayton refrigeration cycle is established, in which finite-time processes and irreversibility in the two adiabatic processes are taken into account. On the basis of the thermodynamic properties of an ideal Bose gas, by using the optimal control-theory, the mathematical expressions for several important performance parameters, such as the coefficient of performance, power input and cooling load, are derived and some important performance parameters, e.g., the temperatures of the working substance at several important state-points, are optimized. By means of numerical predictions, the optimal performance characteristic curves of a Bose-Brayton refrigeration cycle are obtained and analyzed. Furthermore, some optimal operating regions including those for the cooling load, coefficient of performance and the temperatures of the cyclic working substance at the two important state-points are determined and evaluated. Finally, several special cases are discussed in detail

  15. Peptidyl cyclopropenones: Reversible inhibitors, irreversible inhibitors, or substrates of cysteine proteases?

    OpenAIRE

    Cohen, Meital; Bretler, Uriel; Albeck, Amnon

    2013-01-01

    Peptidyl cyclopropenones were previously introduced as selective cysteine protease reversible inhibitors. In the present study we synthesized one such peptidyl cyclopropenone and investigated its interaction with papain, a prototype cysteine protease. A set of kinetics, biochemical, HPLC, MS, and 13C-NMR experiments revealed that the peptidyl cyclopropenone was an irreversible inhibitor of the enzyme, alkylating the catalytic cysteine. In parallel, this cyclopropenone also behaved as an alter...

  16. TRPM8 axonal expression is decreased in painful human teeth with irreversible pulpitis and cold hyperalgesia

    OpenAIRE

    Alvarado, Lisa T.; Perry, Griffin M.; Hargreaves, Kenneth M.; Henry, Michael A.

    2007-01-01

    Pulpitis pain may be triggered by a cold stimulus, yet the cellular mechanisms responsible for this phenomenon are largely unknown. One possible mechanism involves the direct activation of cold-responsive thermoreceptors. The purpose of this study was to evaluate the possible role of the TRPM8 thermoreceptor in cold-mediated noxious pulpal pain mechanisms by comparing expression patterns in pulpal nerves from healthy control molars to cold-sensitive painful molars with irreversible pulpitis. ...

  17. Fourteenβ-(bromoacetamido)morphine irreversibly labels μ opioid receptors in rat brain membranes

    International Nuclear Information System (INIS)

    The binding properties of 14β-(bromoacetamido)morphine (BAM) and the ability of BAM to irreversibly inhibit opioid binding to rat brain membranes were examined to characterize the affinity and selectivity of BAM as an irreversible affinity ligand for opioid receptors. BAM had the same receptor selectivity as morphine, with a 3-5-fold decrease in affinity for the different types of opioid receptors. When brain membranes were incubated with BAM, followed by extensive washing, opioid binding was restored to control levels. However, when membranes were incubated with dithiothreitol (DTT), followed by BAM, and subsequently washed, 90% of the 0.25 nM [3H][D-Ala2,(Me)Phe4,Gly(ol)5]enkephalin (DAGO) binding was irreversibly inhibited as a result of the specific alkylation of a sulfhydryl group at the μ binding site. This inhibition was dependent on the concentrations of both DTT and BAM. The μ receptor specificity of BAM alkylation was demonstrated by the ability of BAM alkylated membranes to still bind the δ-selective peptide [3H][D-penicillamine2,D-penicillamine5]enkephalin (DPDPE) and (-)-[3H]bremazocine in the presence of μ and δ blockers, selective for κ binding sites. Morphine and naloxone partially protected the binding site from alkylation with BAM, while ligands that did not bind to the μs site did not afford protection. These studies have demonstrated that when a disulfide bond at or near μ opioid binding sites was reduced, BAM could then alkylate this site, resulting in the specific irreversible labeling of μ opioid receptors

  18. The Market for Used Capital: Endogenous Irreversibility and Reallocation over the Business Cycle

    OpenAIRE

    Andrea Lanteri

    2013-01-01

    This paper explains the procyclicality of capital reallocation documented by Eisfeldt and Rampini (2006) and Cui (2012) by endogenising the resale price of capital in a dynamic general equilibrium model with heterogeneous firms hit by aggregate and idiosyncratic productivity shocks. I build a simple theory of endogenous investment irreversibility by assuming that used investment goods are imperfect substitutes for newly produced ones because of firm-level capital specificity. This creates a d...

  19. IRREVERSIBLE INVESTMENT DECISIONS IN PERENNIAL CROPS WITH YIELD AND PRICE UNCERTAINTY

    OpenAIRE

    Price, T. Jeffrey; Wetzstein, Michael E.

    1999-01-01

    Optimal entry and exit thresholds for Georgia commercial peach production are calculated when both price and yield follow a Brownian motion process. The thresholds are based on an irreversible sunk-cost investment model, where revenue from peach production is affected by the timing of when to enter production. Results indicate stability in Georgia peach production, with growers who are currently producing peaches remaining in production and potential peach growers delaying investment unless t...

  20. The Influence of a Metal Stent on the Distribution of Thermal Energy during Irreversible Electroporation

    OpenAIRE

    Scheffer, Hester J.; Vogel, Jantien A; Willemien van den Bos; Neal, Robert E.; van Lienden, Krijn P; Besselink, Marc G. H.; van Gemert, Martin J. C.; van der Geld, Cees W. M.; Meijerink, Martijn R; Klaessens, John H.; Rudolf M. Verdaasdonk

    2016-01-01

    Purpose Irreversible electroporation (IRE) uses short duration, high-voltage electrical pulses to induce cell death via nanoscale defects resulting from altered transmembrane potential. The technique is gaining interest for ablations in unresectable pancreatic and hepatobiliary cancer. Metal stents are often used for palliative biliary drainage in these patients, but are currently seen as an absolute contraindication for IRE due to the perceived risk of direct heating of the metal and its sur...

  1. A relation between irreversibility and unlinkability for biometric template protection algorithms

    OpenAIRE

    井沼, 学

    2014-01-01

    For biometric recognition systems, privacy protection of enrolled users’ biometric information, which are called biometric templates, is a critical problem. Recently, various template protection algorithms have been proposed and many related previous works have discussed security notions to evaluate the protection performance of these protection algorithms. Irreversibility and unlinkability are important security notions discussed in many related previous works. In this paper, we prove that u...

  2. Irreversible photo- and radiation-induced effects in amorphous films of arsenic trisulfide

    International Nuclear Information System (INIS)

    It is found that irreversible photo- and radiation-induced effects in virgin As2S3 thin films are accompined by the similar changes of their optical properties. The process of homopolar chemical bond breaking in the thin layer alongside with the creation of the differently charged diamagnetic defects associated with the non-equilibrium breaking of chemical bonds is proper in radiation induced effects, only

  3. Fourteen. beta. -(bromoacetamido)morphine irreversibly labels. mu. opioid receptors in rat brain membranes

    Energy Technology Data Exchange (ETDEWEB)

    Bidlack, J.M.; Frey, D.K.; Seyed-Mozaffari, A.; Archer, S. (Univ. of Rochester School of Medicine and Dentistry, NY (USA))

    1989-05-16

    The binding properties of 14{beta}-(bromoacetamido)morphine (BAM) and the ability of BAM to irreversibly inhibit opioid binding to rat brain membranes were examined to characterize the affinity and selectivity of BAM as an irreversible affinity ligand for opioid receptors. BAM had the same receptor selectivity as morphine, with a 3-5-fold decrease in affinity for the different types of opioid receptors. When brain membranes were incubated with BAM, followed by extensive washing, opioid binding was restored to control levels. However, when membranes were incubated with dithiothreitol (DTT), followed by BAM, and subsequently washed, 90% of the 0.25 nM ({sup 3}H)(D-Ala{sup 2},(Me)Phe{sup 4},Gly(ol){sup 5})enkephalin (DAGO) binding was irreversibly inhibited as a result of the specific alkylation of a sulfhydryl group at the {mu} binding site. This inhibition was dependent on the concentrations of both DTT and BAM. The {mu} receptor specificity of BAM alkylation was demonstrated by the ability of BAM alkylated membranes to still bind the {delta}-selective peptide ({sup 3}H)(D-penicillamine{sup 2},D-penicillamine{sup 5})enkephalin (DPDPE) and (-)-({sup 3}H)bremazocine in the presence of {mu} and {delta} blockers, selective for {kappa} binding sites. Morphine and naloxone partially protected the binding site from alkylation with BAM, while ligands that did not bind to the {mu}s site did not afford protection. These studies have demonstrated that when a disulfide bond at or near {mu} opioid binding sites was reduced, BAM could then alkylate this site, resulting in the specific irreversible labeling of {mu} opioid receptors.

  4. Boltzmann-Equation Based Derivation of Balance Laws in Irreversible Thermodynamics

    OpenAIRE

    Hong, Liu; Yang, Zaibao; Zhu, Yi; Yong, Wen-An

    2014-01-01

    In this paper we propose a novel approach to construct macroscopic balance equations and constitutive equations describing various irreversible phenomena. It is based on the general principles of non-equilibrium thermodynamics and consists of four basic steps: picking suitable state variables, choosing a strictly concave entropy function, separating entropy fluxes and production rates properly, and determining a dissipation matrix. Our approach takes the advantage of both EIT and GENERIC form...

  5. Rapid irreversible encephalopathy associated with anti-D immune globulin treatment for idiopathic thrombocytopenic purpura.

    Science.gov (United States)

    Christopher, Kenneth; Horkan, Clare; Barb, Ilie T; Arbelaez, Christian; Hodgdon, Travis A; Yodice, Paul C

    2004-11-01

    Intravenous Rho (D) immune globulin (IV RhIG, WinRho SDF) has been shown to be a safe treatment for idiopathic thrombocytopenic purpura (ITP). Common side effects of IV RhIG include mild hemolysis, febrile reaction, and headache. Significant hemolysis with renal impairment following IV RhIG has been reported. We report a case of irreversible encephalopathy 48 hr following an infusion of IV RhIG for treatment of ITP. PMID:15495245

  6. A Three-Dimensional In Vitro Tumor Platform for Modeling Therapeutic Irreversible Electroporation

    OpenAIRE

    Arena, Christopher B.; Szot, Christopher S.; Garcia, Paulo A.; Rylander, Marissa Nichole; Davalos, Rafael V.

    2012-01-01

    Irreversible electroporation (IRE) is emerging as a powerful tool for tumor ablation that utilizes pulsed electric fields to destabilize the plasma membrane of cancer cells past the point of recovery. The ablated region is dictated primarily by the electric field distribution in the tissue, which forms the basis of current treatment planning algorithms. To generate data for refinement of these algorithms, there is a need to develop a physiologically accurate and reproducible platform on which...

  7. Uncertainty, instability, and irreversible investment : theory, evidence, and lessons for Africa

    OpenAIRE

    Serven, Luis

    1997-01-01

    A recent (but rapidly growing) literature has focused on how uncertainty and instability affect the adoption of fixed investment projects. That literature shows that if fixed investment projects are costly or impossible to reverse, uncertainty can become a powerful deterrent to investment. The author reviews the literature on irreversible investment to identify the implications for macroeconomic policy and to gauge the practical importance, especially for sub-Saharan Africa, of the link betwe...

  8. The Carnot Cycle for Small Systems: Irreversibility and the Cost of Operations

    OpenAIRE

    Sekimoto, Ken; Takagi, Fumiko; Hondou, Tsuyoshi

    1999-01-01

    We employ the recently developed framework of the energetics of stochastic processes (called `stochastic energetics'), to re-analyze the Carnot cycle in detail, taking account of fluctuations, without taking the thermodynamic limit. We find that both processes of connection to and disconnection from heat baths and adiabatic processes that cause distortion of the energy distribution are sources of inevitable irreversibility within the cycle. Also, the so-called null-recurrence property of the ...

  9. Broken versus Non-Broken Time Reversal Symmetry: Irreversibility and Response

    Directory of Open Access Journals (Sweden)

    Sara Dal Cengio

    2016-07-01

    Full Text Available We review some approaches to macroscopic irreversibility from reversible microscopic dynamics, introducing the contribution of time dependent perturbations within the framework of recent developments in non-equilibrium statistical physics. We show that situations commonly assumed to violate the time reversal symmetry (presence of magnetic fields, rotating reference frames, and some time dependent perturbations in reality do not violate this symmetry, and can be treated with standard theories and within standard experimental protocols.

  10. Irreversible-thermodynamic Analysis of the Efficienty of PEM Transport Processes

    Czech Academy of Sciences Publication Activity Database

    Němec, Tomáš; Maršík, František

    Bialystok : Bialystok Technical University, 2008 - (Butrymowicz, D.; Goscik, J.; Skiepko, T.), s. 479-482 [HEAT 2008 /5./. Bialystok (PL), 30.06.2008-03.07.2008] R&D Projects: GA AV ČR KJB400760701; GA MŠk(CZ) 1M06031; GA ČR(CZ) GA101/07/1612 Institutional research plan: CEZ:AV0Z20760514 Keywords : PEM fuel cell * efficiency * irreversible thermodynamics Subject RIV: BJ - Thermodynamics

  11. A general kinetic method to predict sequence length distributions for non-linear irreversible multicomponent polymerizations

    OpenAIRE

    Dias, Rolando; Costa, Mário Rui

    2006-01-01

    A method to predict the sequence length distribution (SLD) for homogeneous non-linear irreversible multicomponent polymerizations is described. With more than two monomers, it also predicts chain length distributions of the sub-domains containing a prescribed sub-set of the repeating units, but in all possible orderings. Its goal is the analysis of polymerization systems involving complex kinetic schemes in an automated way. The radical terpolymerization of two vinyl monomers with a divinyl m...

  12. Irreversible Denaturation of Maltodextrin Glucosidase Studied by Differential Scanning Calorimetry, Circular Dichroism, and Turbidity Measurements

    OpenAIRE

    Goyal, Megha; Chaudhuri, Tapan K; Kuwajima, Kunihiro

    2014-01-01

    Thermal denaturation of Escherichia coli maltodextrin glucosidase was studied by differential scanning calorimetry, circular dichroism (230 nm), and UV-absorption measurements (340 nm), which were respectively used to monitor heat absorption, conformational unfolding, and the production of solution turbidity. The denaturation was irreversible, and the thermal transition recorded at scan rates of 0.5–1.5 K/min was significantly scan-rate dependent, indicating that the thermal denaturation was ...

  13. Irreversible thermodynamic description of interacting dark energy - dark matter cosmological models

    OpenAIRE

    Harko, Tiberiu; Lobo, Francisco S N

    2012-01-01

    We investigate the interaction between dark energy and dark matter in the framework of irreversible thermodynamics of open systems with matter creation/annihilation. We consider dark energy and dark matter as an interacting two component (scalar field and "ordinary" dark matter) cosmological fluid in a homogeneous spatially flat and isotropic Friedmann-Robertson-Walker (FRW) Universe. The thermodynamics of open systems as applied together with the gravitational field equations to the two comp...

  14. Microbiome of Deep Dentinal Caries Lesions in Teeth with Symptomatic Irreversible Pulpitis

    Science.gov (United States)

    Rôças, Isabela N.; Rachid, Caio T. C. C.; Lima, Kenio C.; Assunção, Isauremi V.; Gomes, Patrícia N.; Siqueira, José F.

    2016-01-01

    This study used a next-generation sequencing approach to identify the bacterial taxa occurring in the advanced front of caries biofilms associated with pulp exposure and irreversible pulpitis. Samples were taken from the deepest layer of dentinal caries lesions associated with pulp exposure in 10 teeth diagnosed with symptomatic irreversible pulpitis. DNA was extracted and the microbiome was characterized on the basis of the V4 hypervariable region of the 16S rRNA gene by using paired-end sequencing on Illumina MiSeq device. Bacterial taxa were mapped to 14 phyla and 101 genera composed by 706 different OTUs. Three phyla accounted for approximately 98% of the sequences: Firmicutes, Actinobacteria and Proteobacteria. These phyla were also the ones with most representatives at the species level. Firmicutes was the most abundant phylum in 9/10 samples. As for genera, Lactobacillus accounted for 42.3% of the sequences, followed by Olsenella (13.7%), Pseudoramibacter (10.7%) and Streptococcus (5.5%). Half of the samples were heavily dominated by Lactobacillus, while in the other half lactobacilli were in very low abundance and the most dominant genera were Pseudoramibacter, Olsenella, Streptococcus, and Stenotrophomonas. High bacterial diversity occurred in deep dentinal caries lesions associated with symptomatic irreversible pulpitis. The microbiome could be classified according to the relative abundance of Lactobacillus. Except for Lactobacillus species, most of the highly prevalent and abundant bacterial taxa identified in this study have been commonly detected in infected root canals. The detected taxa can be regarded as candidate pathogens for irreversible pulpitis and possibly the pioneers in pulp invasion to initiate endodontic infection. PMID:27135405

  15. Irreversible electroporation in the treatment of locally advanced pancreas and liver metastases of colorectal carcinoma

    OpenAIRE

    Wichtowski, Mateusz; Nowaczyk, Piotr; Kocur, Jacek; Murawa, Dawid

    2016-01-01

    Aim of the study Irreversible electroporation is a new, non-thermal ablation technique in the treatment of parenchymal organ tumors which uses short high voltage pulses of electricity in order to induce apoptosis of targeted cells. In this paper the application of this method of treatment in locally advanced pancreatic cancer (LAPC) and liver cancer is analyzed. Material and methods Between 04.2014 and 09.2014 two patients with LAPC and one with colorectal liver metastasis (CRLM) were qualifi...

  16. A statistical model describing combined irreversible electroporation and electroporation-induced blood-brain barrier disruption

    Directory of Open Access Journals (Sweden)

    Sharabi Shirley

    2016-03-01

    Full Text Available Electroporation-based therapies such as electrochemotherapy (ECT and irreversible electroporation (IRE are emerging as promising tools for treatment of tumors. When applied to the brain, electroporation can also induce transient blood-brain-barrier (BBB disruption in volumes extending beyond IRE, thus enabling efficient drug penetration. The main objective of this study was to develop a statistical model predicting cell death and BBB disruption induced by electroporation. This model can be used for individual treatment planning.

  17. A statistical model describing combined irreversible electroporation and electroporation-induced blood-brain barrier disruption

    OpenAIRE

    Sharabi Shirley; Kos Bor; Last David; Guez David; Daniels Dianne; Harnof Sagi; Mardor Yael; Miklavcic Damijan

    2016-01-01

    Background Electroporation-based therapies such as electrochemotherapy (ECT) and irreversible electroporation (IRE) are emerging as promising tools for treatment of tumors. When applied to the brain, electroporation can also induce transient blood-brain-barrier (BBB) disruption in volumes extending beyond IRE, thus enabling efficient drug penetration. The main objective of this study was to develop a statistical model predicting cell death and BBB disruption induced by electroporation. This m...

  18. Local Ablative Strategies for Ductal Pancreatic Cancer (Radiofrequency Ablation, Irreversible Electroporation): A Review

    OpenAIRE

    Salvatore Paiella; Roberto Salvia; Marco Ramera; Roberto Girelli; Isabella Frigerio; Alessandro Giardino; Valentina Allegrini; Claudio Bassi

    2016-01-01

    Pancreatic ductal adenocarcinoma (PDAC) has still a dismal prognosis. Locally advanced pancreatic cancer (LAPC) accounts for the 40% of the new diagnoses. Current treatment options are based on chemo- and radiotherapy regimens. Local ablative techniques seem to be the future therapeutic option for stage-III patients with PDAC. Radiofrequency Ablation (RFA) and Irreversible Electroporation (IRE) are actually the most emerging local ablative techniques used on LAPC. Initial clinical studies on ...

  19. Exergetic efficiency optimization for an irreversible heat pump working on reversed Brayton cycle

    Indian Academy of Sciences (India)

    Yuehong Bi; Lingen Chen; Fengrui Sun

    2010-03-01

    This paper deals with the performance analysis and optimization for irreversible heat pumps working on reversed Brayton cycle with constant-temperature heat reservoirs by taking exergetic efficiency as the optimization objective combining exergy concept with finite-time thermodynamics (FTT). Exergetic efficiency is defined as the ratio of rate of exergy output to rate of exergy input of the system. The irreversibilities considered in the system include heat resistance losses in the hot- and cold-side heat exchangers and non-isentropic losses in the compression and expansion processes. The analytical formulas of the heating load, coefficient of performance (COP) and exergetic efficiency for the heat pumps are derived. The results are compared with those obtained for the traditional heating load and coefficient of performance objectives. The influences of the pressure ratio of the compressor, the allocation of heat exchanger inventory, the temperature ratio of two reservoirs, the effectiveness of the hot- and cold-side heat exchangers and regenerator, the efficiencies of the compressor and expander, the ratio of hot-side heat reservoir temperature to ambient temperature, the total heat exchanger inventory, and the heat capacity rate of the working fluid on the exergetic efficiency of the heat pumps are analysed by numerical calculations. The results show that the exergetic efficiency optimization is an important and effective criterion for the evaluation of an irreversible heat pump working on reversed Brayton cycle.

  20. Calcium-Enriched Mixture Pulpotomy of Primary Molar Teeth with Irreversible Pulpitis. A Clinical Study

    Science.gov (United States)

    Memarpour, Mahtab; Fijan, Soleiman; Asgary, Saeed; Keikhaee, Marzieh

    2016-01-01

    Objectives: To evaluate the outcome of vital pulp therapy in primary teeth with irreversible pulpitis by using calcium-enriched mixture (CEM) cement according to clinical and radiographic assessment. Participants and Methods: Fifty primary molar teeth with irreversible pulpitis in 50 children aged 6-8 years underwent pulpotomy using CEM cement as the dressing material. Following pulpotomy, pain intensity was evaluated by use of a visual analog scale at 1 and 7 days from the treatment and in clinical appointments at 3, 6 and 12 months after baseline. Radiographic evaluation was performed at 6 and 12 months. Data were analyzed using the McNemar test. Results: A total of 42 children (mean age 7.26 ± 0.82 year) completed the study. After one day treatment 56 % of children reported complete relief of pain and after 7 days 62% reported the same. However, two children complained of increased pain 1 day after treatment. None of the children reported pain in the subsequent appointments. One child complained of tenderness in percussion after 6 months. Pulp canal obliteration was the most common change in the radiographic assessment. There was no significant difference between clinical (92.8%) and radiographic (90.4%) success (p=0.990). Conclusion: Pulpotomy using CEM cement could present a successful treatment in primary molar teeth with irreversible pulpitis. PMID:27326265

  1. Magnetic irreversibility and relaxation in CuFe{sub 2}O{sub 4} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Goya, G.F. E-mail: goya@macbeth.if.usp.br; Rechenberg, H.R.; Jiang, J.Z

    2000-08-01

    In this work, we present a study on the magnetic behavior of CuFe{sub 2}O{sub 4} nanoparticles with different particle sizes. Magnetic particle size distribution obtained from M(H) curves in the superparamagnetic (SPM) state showed good agreement with data obtained from X-ray powder diffraction. Field-cooled and zero-field-cooled magnetization data showed a blocking temperature T{sub B}{approx}225 K, independent of particle size, which is associated to interparticle interactions. It was observed that T{sub B} and the irreversibility temperature T{sub irr}, shift to lower temperature with increasing applied fields, both with an H{sup -1} dependence. Strong training effects were observed from relaxation data, assigned to the irreversible behavior of the spin-disordered particle surface. The magnetic viscosity at T=4.2 K was analyzed for sample with D{sub mean}=7.7 nm, revealing strong irreversibility after each major hysteresis loop. These results are discussed in terms of multiple spin-disordered configurations, at particle surface, with quasidegenerate states.

  2. Non-Equilibrium Thermodynamic Analysis on the Performance of AN Irreversible Thermally Driven Brownian Motor

    Science.gov (United States)

    Gao, Tianfu; Chen, Jincan

    Based on the general model of thermally-driven Brownian motors, an equivalent cycle system is established and the Onsager coefficients and efficiency at the maximum power output of the system are analytically calculated from non-equilibrium thermodynamics. It is found that the Onsager reciprocity relation holds and the Onsager coefficients are affected by the main irreversibilities existing in practical systems. Only when the heat leak and the kinetic energy change of the particle in the system are negligible, can the determinant of the Onsager matrix vanish. It is also found that in the frame of non-equilibrium thermodynamics, the power output and efficiency of an irreversible Brownian motor can be expressed to be the same form as those of an irreversible Carnot heat engine, so the results obtained here are of general significance. Moreover, these results are used to analyze the performance characteristics of a class of thermally-driven Brownian motors so that some important conclusions in literature may be directly derived from the present paper.

  3. Note on magnesite formation (Studies on irreversible geochemical reactions N° 9

    Directory of Open Access Journals (Sweden)

    Deelmann John C.

    2003-12-01

    Full Text Available In recent laboratory experiments magnesite (MgC03 has been synthesized at a temperature of 313°K (= 40°C. The experiments have demonstrated that irreversible reactions are involved in the low-temperature formation of magnesite. Fundamental to such irreversible reactions is a requirement for fluctuations, i.e., alternations between precipitation and dissolution. But unequivocal evidence for the necessity for fluctuations in order to produce such irreversible geochemical reactions can be demonstrated only by static control experiments. The present note describes several static control experiments on the low-temperature synthesis of magnesite. The first experiment consisted of adding the total amount of ammonia (used in the original experiment in 14 different titration steps in a single action: only magnesium hydroxide carbonate formed, not magnesite. In the second experiment the possible reaction between magnesium chloride, ammonia and carbon dioxide in solution was studied at 318°K (= 45°C: magnesium hydroxide formed, not magnesite. The third static control experiment involved the reaction between magnesium chloride and ammonium carbamate; this time nesquehonite formed, not magnesite. The implications of these static control experiments in relation to the low-temperature formation of magnesite and dolomite in the sedimentary environment are discussed.

  4. Influence of defects on the irreversible phase transition in Fe–Pd ferromagnetic shape memory alloys

    International Nuclear Information System (INIS)

    In Fe–Pd ferromagnetic shape memory alloys a face-centered tetragonal (fct) martensite can be obtained when cooling the face-centered cubic austenite through the martensite transition. Nevertheless, further irreversible transformation on cooling into a body-centered tetragonal (bct) martensite needs to be prevented in order to retain the shape memory properties. Differential scanning calorimetry experiments demonstrate that high temperature thermal treatments stabilize the fct phase, reducing the fct–bct transformation temperature. A large misfit between the cell parameters of fct and bct phases was determined by neutron diffraction, pointing to the critical role of dislocations in the accommodation of both phases. The presence of dislocations and its dynamics was analyzed by mechanical spectroscopy, and a relaxation peak at ∼443 K related to the dislocation movement was identified. The driving force of the relaxation process can be proposed as a dislocation dragging mechanism controlled by the migration of vacancies without break-away. Defects such as dislocations and vacancies have been shown to play an important role in changing the irreversible phase transformation temperature. A reduction in the dislocation density reduces the irreversible transformation temperature and so increases the stability range of the alloy

  5. Novel Selective and Irreversible Mosquito Acetylcholinesterase Inhibitors for Controlling Malaria and Other Mosquito-Borne Diseases

    Science.gov (United States)

    Dou, Dengfeng; Park, Jewn Giew; Rana, Sandeep; Madden, Benjamin J.; Jiang, Haobo; Pang, Yuan-Ping

    2013-01-01

    We reported previously that insect acetylcholinesterases (AChEs) could be selectively and irreversibly inhibited by methanethiosulfonates presumably through conjugation to an insect-specific cysteine in these enzymes. However, no direct proof for the conjugation has been published to date, and doubts remain about whether such cysteine-targeting inhibitors have desirable kinetic properties for insecticide use. Here we report mass spectrometric proof of the conjugation and new chemicals that irreversibly inhibited African malaria mosquito AChE with bimolecular inhibition rate constants (kinact/KI) of 3,604-458,597 M-1sec-1 but spared human AChE. In comparison, the insecticide paraoxon irreversibly inhibited mosquito and human AChEs with kinact/KI values of 1,915 and 1,507 M-1sec-1, respectively, under the same assay conditions. These results further support our hypothesis that the insect-specific AChE cysteine is a unique and unexplored target to develop new insecticides with reduced insecticide resistance and low toxicity to mammals, fish, and birds for the control of mosquito-borne diseases.

  6. Understanding Irreversible Degradation of Nb3Sn Wires with Fundamental Fracture Mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Yuhu [PPPL; Calzolaio, Ciro [Univ of Geneva; Senatore, Carmine [Univ of Geneva

    2014-08-01

    Irreversible performance degradation of advanced Nb3Sn superconducting wires subjected to transverse or axial mechanical loading is a critical issue for the design of large-scale fusion and accelerator magnets such as ITER and LHC. Recent SULTAN tests indicate that most cable-in-conduit conductors for ITER coils made of Nb3Sn wires processed by various fabrication techniques show similar performance degradation under cyclic loading. The irreversible degradation due to filament fracture and local strain accumulation in Nb3Sn wires cannot be described by the existing strand scaling law. Fracture mechanic modeling combined with X-ray diffraction imaging of filament micro-crack formation inside the wires under mechanical loading may reveal exciting insights to the wire degradation mechanisms. We apply fundamental fracture mechanics with a singularity approach to study influence of wire filament microstructure of initial void size and distribution to local stress concentration and potential crack propagation. We report impact of the scale and density of the void structure on stress concentration in the composite wire materials for crack initiation. These initial defects result in an irreversible degradation of the critical current beyond certain applied stress. We also discuss options to minimize stress concentration in the design of the material microstructure for enhanced wire performance for future applications.

  7. Irreversibility behavior in Ag-sheathed Bi-based superconducting wires

    Energy Technology Data Exchange (ETDEWEB)

    Dou, S.X.; Liu, H.K.; Guo, Y.C.; Wang, J.; Jin, X.J.; Hu, Q.Y. (New South Wales Univ., Kensington (Australia)); Shi, D.L.; Salem-Sugui, S.; Wang, Z. (Argonne National Lab., IL (United States))

    1992-04-01

    Irreversibility lines for Ag/(Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub y}(2223) wires prepared through a phase formation- decomposition-recovery (PFDR) process and normal annealing process were determined using both AC susceptibility measurements under DC fields and magnetisation measurements. It was found that flux pinning was enhanced in the PFDR processed samples over the normal processed samples, in particular at temperature above 77 K. The PFDR process results in high mass density, grain alignment, uniform distribution of impurity precipitates and high density of defects. The irreversibility temperatures scaled with the applied field according to H{sup 1/3}, which is in contrast to H{sup 2/3} law for YBa{sub 2}Cu{sub 3}O{sub 7-x} and conventional superconductors. The irreversibility lines for PFDR processed tapes showed a crossover with those for normal processed tapes at temperature below {Tc} of the (Bi,Pb){sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+x} (2212), suggesting that at temperature above {Tc} of the 2212 phase, the 2212 as nonsuperconducting region, may serve as effective pinning sites for fluxoids.

  8. Irreversibility behavior in Ag-sheathed Bi-based superconducting wires

    Science.gov (United States)

    Dou, S. X.; Liu, H. K.; Guo, Y. C.; Wang, J.; Jin, X. J.; Hu, Q. Y.; Shi, D. L.; Salem-Sugui, S.; Wang, Z.

    1992-04-01

    Irreversibility lines for Ag/(Bi,Pb)2Sr2Ca2Cu3O(y)(2223) wires prepared through a phase formation- decomposition-recovery (PFDR) process and normal annealing process were determined using both AC susceptibility measurements under DC fields and magnetization measurements. It was found that flux pinning was enhanced in the PFDR processed samples over the normal processed samples, in particular at temperatures above 77 K. The PFDR process results in high mass density, grain alignment, uniform distribution of impurity precipitates, and high density of defects. The irreversibility temperatures scaled with the applied field according to H(sup 1/3), which is in contrast to H(sup 2/3) law for YBa2Cu3O(7-x) and conventional superconductors. The irreversibility lines for PFDR processed tapes showed a crossover with those for normal processed tapes at temperatures below T(sub c) of the (Bi,Pb)2Sr2CaCu2O(8+x) (2212), suggesting that at temperatures above T(sub c) of the 2212 phase, the 2212 as a nonsuperconducting region, may serve as effective pinning sites for fluxoids.

  9. Generalization of the singular normal mode method for isothermal irreversible Vlasov systems

    International Nuclear Information System (INIS)

    Irreversible Vlasov systems, i.e. systems governed by a Vlasov-type kinetic equation including entropy-producing collision terms, are treated by the techniques of singular normal modes and singular integral equations using a new indirect method which renders possible a straightforward generalization of the Case formalism as developed originally for collision-free Vlasov plasmas. This method is in contrast to a more complex method given by the present authors for the first application of the singular normal mode expansion to irreversible Vlasov systems (1970). The linearized Vlasov operator supplemented by complete Bhatnagar-Gross-Krook collision integrals as the most important model collision terms is analyzed in detail for a nonrelativistic, nondegenerate, stationary electron gas with neutralizing positive ions and neutral particles without a magnetic field at constant temperature, generalizations for more complex irreversible Vlasov systems being possible. The key of the indirect method given is the introduction of a transformed electron distribution function containing as an additive term an integral over the usual distribution function. The new kinetic equation and its adjoint equation become again linear integral equations and yield a set of regular and singular normal modes which are proved to be orthogonal and complete. The initial value problem is solved exactly. A comparison is made with the Laplace transform theory of Landau which for the full Vlasov-BGK equation is recast into a compact form. The time-behaviour of the solutions is discussed. (author)

  10. Climate Change and the Irreversibility Effect. Combining Expected Utility and MaxiMin

    Energy Technology Data Exchange (ETDEWEB)

    Lange, A. [Centre for European Economic Research (ZEW), P.O.Box 103443, D-68034 Mannheim (Germany)

    2003-08-01

    This paper analyzes decisions on emissions of a stock pollutant under uncertainty in a two period model. Decisions are based on a weighted average of expected utility (EU) and the MaxiMin criterion. I first show that more weight on the worst case (less weight on EU) may lead to increased first period emissions. The effect of learning possibilities on emissions is not clear in general, but depends qualitatively on the weight given to MaxiMin: For the quadratic utility case, considering prospective learning increases today's abatement effort, i.e. the ``irreversibility effect'' holds, if the weight on EU is small. This contrasts standard results on the irreversibility effect for EU which translates to small weights on MaxiMin. There is, however, the possibility of a negative value of learning. It is shown that the irreversibility effect holds if and only if the value of learning is negative. Consequences for the applicability of generalized EU-MaxiMin are discussed.

  11. New hierarchy for the Liouville equation, irreversibility and Fokker-Planck-like structures

    International Nuclear Information System (INIS)

    The issue of irreversibility is revisited for a closed system formed by N classical non-relativistic particles inside a volume Ω, interacting through two-body potentials, for large N and Ω. The classical phase-space distribution function f, multiplied by suitable Hermite polynomials and integrated over all momenta, yields new moments. The Liouville equation and the initial distribution fin imply a new non-equilibrium linear infinite hierarchy for the moments. That hierarchy differs from the BBGKY one for distribution functions and displays some suggestive Fokker-Planck-like structures. A physically motivated ansatz for fin (which introduces statistical assumptions), used by previous authors, is chosen. All moments of order n ≥ n0 are expressed in terms of those of order n0 - 1 and of fin. The properties of the Fokker-Planck-like structures (hermiticity, non-negative eigenvalues) allow for implementing a natural long-time approximation in the hierarchy, so as to introduce relaxation to equilibrium and irreversibility, consistently with the hydrodynamical balance equations. Further (more restrictive) assumptions and approximations lead to new irreversible models, generalizing non-trivially the Fokker-Planck equation. They are described through a truncated hierarchy of linear equations for moments of order n ≤ n0 - 1 (n0 being finite). The connections with Brownian particle dynamics and Fluid Dynamics are analyzed, for consistency. (orig.)

  12. Endothelial dysfunction and atherosclerosis in children with irreversible pulmonary hypertension due to congenital heart disease

    International Nuclear Information System (INIS)

    To assess endothelial dysfunction and the risk for coronary atherosclerosis in children with irreversible pulmonary hypertension due to congenital heart disease (CHD). The study included 18 cyanotic patients (the mean age was 12.28 ± 3.26 years) who developed irreversible pulmonary hypertension due to cyanotic and acyanotic CHDs, and 18 control patients (the mean age was 11.78 ± 3.00 years). Study groups were compared for flow-mediated dilatation (FMD), carotid intima media thickness (CIMT) and atherosclerotic risk factors. Compared to the control group, the mean FMD was significantly reduced in the cyanotic group (5.26 ± 2.42% and 9.48 ± 2.60%, respectively; P-value < 0.001). No significant difference was observed between the groups in CIMT (0.41 ± 0.08 mm and 0.39 ± 0.06 mm, respectively; P-value = 0.299). The levels of total cholesterol, low-density lipoprotein–cholesterol and very low-density lipoprotein–cholesterol were statistically significantly lower compared tothe control group (P-value = 0.001, 0.006 and 0.014, respectively), whereas no statistically significant difference was found in the levels of high-density lipoprotein–cholesterol and triglycerides (P-value = 0.113 and 0.975, respectively). Systemic endothelial dysfunction in children with irreversible pulmonary hypertension due to CHD was noted but there was no increased risk for atherosclerosis

  13. Rules to transform concentrations and currents for irreversible reactions to those of quasireversible reactions

    International Nuclear Information System (INIS)

    Highlights: • Simple rules convert irreversible analytical solutions to quasireversible ones • These work for many common convective diffusion situations • Rules involve substitution of kf by kf + kb then scaling and constant addition • Irreversible numerical solutions can be converted to quasireversible ones - Abstract: Transformation rules are given that take the concentration or current expressions for the simple irreversible electron-transfer reaction R → P + e− and convert them to the corresponding quantities for the quasireversible reaction. They apply for many standard electrochemical mass-transport cases, including simple diffusion and convection-diffusion for the rotating disk or channel flow, provided that the diffusivities of the two species are equal. The forward rate constant is replaced by the sum of the forward and reverse rate constants, the result is scaled and then a constant added. Rules are also given for some cases where the diffusivities are unequal. As an application, a new solution of the concentration profile for a channel electrode within the Lévêque approximation neglecting axial diffusion is given

  14. Influence of irreversible losses on the performance of a two-stage magnetic Brayton refrigeration cycle

    International Nuclear Information System (INIS)

    The general performance characteristics of a two-stage magnetic Brayton refrigeration cycle consisting of three constant magnetic fields and three irreversible adiabatic processes are investigated. Based on the thermodynamic properties of a magnetic material and the irreversible cycle model of a two-stage Brayton refrigerator, expressions for the cooling load and coefficient of performance of the refrigeration system are derived. The influence of the finite-rate heat transfer in the heat exchange processes, irreversibilities in the three adiabatic processes, ratios of two magnetic fields in the three constant magnetic field processes, and heat leak losses between two heat reservoirs on the performance of the two-stage magnetic Brayton refrigeration cycle are analyzed in detail. Some important performance curves, which can reveal the general characteristics of the refrigeration system, are presented and the maximum values of cooling load and coefficient of performance are numerically calculated. The optimal choices and matches of other parameters at the maximum cooling load or the maximum coefficient of performance are discussed and the optimally operating regions of some important parameters in the refrigeration system are determined. The results obtained here are compared with those derived from other models of the magnetic Brayton refrigeration cycles, and consequently, the advantage of an inter-cooled process is expounded.

  15. Performance analysis and parametric optimal criteria of an irreversible magnetic Brayton-refrigerator

    International Nuclear Information System (INIS)

    An irreversible magnetic Brayton refrigeration-cycle model is established, in which the thermal resistance and irreversibility in the two adiabatic processes are taken into account. Based on the model, the performance characteristics of the magnetic Brayton refrigeration-cycle are investigated and the effects of the irreversibilities and the ratio of the magnetic fields in the two iso-field processes on the performance of the refrigeration cycle are revealed. On the basis of the thermodynamic properties of a paramagnetic material, by using the optimal control-theory, the mathematical expressions for the cooling load and the coefficient of performance are derived and some important performance parameters, e.g., the temperatures of the working substance at several important state-points, are optimized. By means of numerical predictions, the optimal performance characteristic curves of the magnetic Brayton refrigeration-cycle are obtained and analyzed. Furthermore, some optimal operating-regions including those for the cooling load, coefficient of performance and the temperatures of the cyclic working substance at the two important state-points are determined and evaluated. Finally, several special cases are discussed in detail

  16. In vivo imaging of irreversible electroporation by means of electrical impedance tomography

    International Nuclear Information System (INIS)

    Electroporation, the increased permeability of cell membranes due to a large transmembrane voltage, is an important clinical tool. Both reversible and irreversible in vivo electroporation are used for clinical applications such as gene therapy and solid malignant tumor ablation, respectively. The primary advantage of in vivo electroporation is the ability to treat tissue in a local and minimally invasive fashion. The drawback is the current lack of control over the process. This paper is the first report of a new method for real-time three-dimensional imaging of an in vivo electroporation process. Using two needle electrodes for irreversible electroporation and a set of electrodes for reconstructing electrical impedance tomography (EIT) images of the treated tissue, we were able to demonstrate electroporation imaging in rodent livers. Histology analysis shows good correlation between the extent of tissue damage caused by irreversible electroporation and the EIT images. This new method may lead the way to real-time control over genetic treatment of diseases in tissue and tissue ablation.

  17. In vivo imaging of irreversible electroporation by means of electrical impedance tomography

    Energy Technology Data Exchange (ETDEWEB)

    Granot, Yair; Maor, Elad; Rubinsky, Boris [Biophysics Graduate Group, University of California at Berkeley, Berkeley, CA 94720 (United States); Ivorra, Antoni [Departments of Mechanical Engineering and Bioengineering, University of California at Berkeley, Berkeley, CA 94720 (United States)], E-mail: yair.granot@gmail.com

    2009-08-21

    Electroporation, the increased permeability of cell membranes due to a large transmembrane voltage, is an important clinical tool. Both reversible and irreversible in vivo electroporation are used for clinical applications such as gene therapy and solid malignant tumor ablation, respectively. The primary advantage of in vivo electroporation is the ability to treat tissue in a local and minimally invasive fashion. The drawback is the current lack of control over the process. This paper is the first report of a new method for real-time three-dimensional imaging of an in vivo electroporation process. Using two needle electrodes for irreversible electroporation and a set of electrodes for reconstructing electrical impedance tomography (EIT) images of the treated tissue, we were able to demonstrate electroporation imaging in rodent livers. Histology analysis shows good correlation between the extent of tissue damage caused by irreversible electroporation and the EIT images. This new method may lead the way to real-time control over genetic treatment of diseases in tissue and tissue ablation.

  18. In vivo imaging of irreversible electroporation by means of electrical impedance tomography

    Science.gov (United States)

    Granot, Yair; Ivorra, Antoni; Maor, Elad; Rubinsky, Boris

    2009-08-01

    Electroporation, the increased permeability of cell membranes due to a large transmembrane voltage, is an important clinical tool. Both reversible and irreversible in vivo electroporation are used for clinical applications such as gene therapy and solid malignant tumor ablation, respectively. The primary advantage of in vivo electroporation is the ability to treat tissue in a local and minimally invasive fashion. The drawback is the current lack of control over the process. This paper is the first report of a new method for real-time three-dimensional imaging of an in vivo electroporation process. Using two needle electrodes for irreversible electroporation and a set of electrodes for reconstructing electrical impedance tomography (EIT) images of the treated tissue, we were able to demonstrate electroporation imaging in rodent livers. Histology analysis shows good correlation between the extent of tissue damage caused by irreversible electroporation and the EIT images. This new method may lead the way to real-time control over genetic treatment of diseases in tissue and tissue ablation.

  19. A derivation of a microscopic entropy and time irreversibility from the discreteness of time

    CERN Document Server

    Riek, Roland

    2014-01-01

    All of the basic microsopic physical laws are time reversible. In contrast, the second law of thermodynamics, which is a macroscopic physical representation of the world, is able to describe irreversible processes in an isolated system through the change of entropy S larger than 0. It is the attempt of the present manuscript to bridge the microscopic physical world with its macrosocpic one with an alternative approach than the statistical mechanics theory of Gibbs and Boltzmann. It is proposed that time is discrete with constant step size. Its consequence is the presence of time irreversibility at the microscopic level if the present force is of complex nature (i.e. not const). In order to compare this discrete time irreversible mechamics (for simplicity a classical, single particle in a one dimensional space is selected) with its classical Newton analog, time reversibility is reintroduced by scaling the time steps for any given time step n by the variable sn leading to the Nose-Hoover Lagrangian. The corresp...

  20. Time-irreversibility of the statistics of a single particle in a compressible turbulence

    CERN Document Server

    Grafke, Tobias; Falkovich, Gregory

    2014-01-01

    We investigate time-irreversibility from the point of view of a single particle in Burgers turbulence. Inspired by the recent work for incompressible flows we analyze the evolution of the kinetic energy for fluid markers and use the fluctuations of the instantaneous power as a measure of time irreversibility. For short times, starting from a uniform distribution of markers, we find the scaling $\\left\\propto t$ and $\\left \\propto \\textrm{Re}^{n-1}$ for the power as a function of the Reynolds number. Both observations can be explained using the "flight-crash" model, suggested by Xu et al. Furthermore, we use a simple model for shocks which reproduces the moments of the energy difference including the pre-factor for $\\left$. To complete the single particle picture for Burgers we compute the moments of the Lagrangian velocity difference and show that they are bi-fractal. This arises in a similar manner to the bi-fractality of Eulerian velocity differences. In the above setting time irreversibility is directly man...

  1. Concerning the study of the irreversible magnetic behaviour of superconductivity; Contribution a l'etude du comportement magnetique irreversible des supraconducteurs

    Energy Technology Data Exchange (ETDEWEB)

    Kuhn, G. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1965-03-01

    The influence of the presence of extended lattice defects on the magnetic behaviour has been studied for the case of type I superconductors, such as Re and Ta, and in a more quantitative manner for the type II superconductor niobium. In this case, measurements of the thermal conductivity have given an estimate of the relative concentration of lattice defects in each specimen. These measurements show that the larger the number of lattice defects, the more irreversible becomes the magnetization curve, and the larger becomes the values of the critical current, which is related by a simple model to the magnetization values. Finally, a study by transmission electron microscopy has confirmed on the one hand the diversity of the extended lattice defects and on the other hand has allowed the formulation of several hypothesis on their respective influence. [French] L'influence de la presence de defauts etendus sur le comportement magnetique a ete etudie pour des supraconducteurs de premiere espece, tels que le rhenium et le tantale, et plus quantitativement pour un supraconducteur de deuxieme espece, le niobium. Dans ce cas, des mesures de conductibilite thermique ont permis d'estimer la concentration relative des defauts du reseau dans chaque echantillon. Ces mesures montrent que plus les defauts du reseau sont nombreux, plus la courbe d'aimantation est irreversible, et plus les valeurs du courant critique, reliees par un modele simple aux valeurs de l'aimantation, sont elevees. Enfin une etude par microscopie electronique en transmission - a permis d'une part de constater la diversite des defauts etendus et d'autre part de formuler quelques hypotheses sur leurs influences respectives.

  2. Relación entre los haplogrupos del ADN mitocondrial y la sordera por cisplatino

    OpenAIRE

    Graterol Torres, Domingo Jesús

    2015-01-01

    • Introducción El cisplatino es un quimioterápico muy eficaz, empleado en múltiples neoplasias de diversos tipos. Sin embargo causa importantes efectos adversos en los pacientes que lo reciben, como por ejemplo: nefrotoxicidad, neurotoxicidad y ototoxicidad. Aproximadamente entre un 20 y 40 % de los pacientes que reciben este fármaco desarrollan ototoxicidad la cual se manifiesta generalmente como pérdida auditiva bilateral, simétrica, irreversible y en frecuencias agudas. Los factores...

  3. Aspergillosis in immunocompromised children acute myeloid leukemia and bone marrow aplasia.: Report of two cases Aspergilose em crianças imunocomprometidas com leucemia mielóide aguda e aplasta de medula óssea: Registro de 2 casos

    Directory of Open Access Journals (Sweden)

    Maria Zilda de Aquino

    1994-10-01

    Full Text Available Two cases of Aspergillosis in immunocompromised children are reported. Both were caused by Aspergillns flavus. Early diagnosis and treatment led to the remission of the process. One patient had acute myeloid leukemia; the fungus was isolated from the blood. The other patient with bone marrow aplasia, presented an invasive aspergillosis of the paranasal sinuses with dissemination of fungal infection; the diagnosis was obtained by histology and culture of biopsied tissue from a palatal ulceration.No presente trabalho são registrados dois casos de aspergilose em crianças imunocomprometidas. O estudo micológico completo identificou Aspergillus flavus como agente dos dois processos. A presença cada vez mais frequente da aspergilose invasiva deve-se ao número crescente de pacientes imunocomprometidos, muitos com hemopatias graves submetidos à quimioterapia. O diagnóstico precoce em um dos casos possibilitou remissão do processo. Tratava-se de paciente com leucemia mielóide aguda, tendo sido isolado o fungo do sangue circulante. O segundo caso evoluiu para óbito, com infecção fúngica generalizada.

  4. Long-term outcome of individuals with pure red cell aplasia and antierythropoietin antibodies in patients treated with recombinant epoetin: a follow-up report from the Research on Adverse Drug Events and Reports (RADAR) Project

    Science.gov (United States)

    Bennett, Charles L.; Cournoyer, Denis; Carson, Kenneth R.; Rossert, Jerome; Luminari, Stefano; Evens, Andrew M.; Locatelli, Francesco; Belknap, Steven M.; McKoy, June M.; Lyons, E. Alison; Kim, Benjamin; Sharma, Rishi; Costello, Stacey; Toffelmire, Edwin B.; Wells, George A.; Messner, Hans A.; Yarnold, Paul R.; Trifilio, Steven M.; Raisch, Dennis W.; Kuzel, Timothy M.; Nissenson, Allen; Lim, Lay-Cheng; Tallman, Martin S.; Casadevall, Nicole

    2005-01-01

    Since its introduction in 1988, recombinant human erythropoietin (epoetin) has been standard treatment for patients with anemia due to chronic kidney disease. From 1998 to 2004, nearly 200 epoetin-treated persons with chronic kidney disease developed antibodies to epoetin, resulting in pure red cell aplasia (PRCA). The majority of these patients received Eprex, an epoetin alfa product marketed exclusively outside the United States. Herein, we report on the long-term outcome of these individuals. For 170 chronic kidney disease patients who developed epoetin-associated PRCA and had 3 months or more follow-up information available, case reports from the Food and Drug Administration and epoetin manufacturers were reviewed for information on clinical characteristics of the patients, immunosuppressive treatments, epoetin responsiveness, and hematologic recovery. Overall, 64% of the PRCA patients received immunosuppressive therapy, including 19 who also underwent a renal transplantation. Thirty-seven percent experienced a hematologic recovery, with higher hematologic recovery rates among PRCA patients who received immunosuppressive therapy (57% vs 2%, P < .001). Among 34 patients who received epoetin after the onset of PRCA, 56% regained epoetin responsiveness. The highest rates of epoetin responsiveness were observed among persons whose antierythropoietin antibodies were undetectable when epoetin was administered (89%). Among chronic kidney disease patients with epoetin-associated PRCA, epoetin discontinuation and immunosuppressive therapy or renal transplantation is necessary for hematologic recovery. Reinitiation of epoetin therapy among individuals could be considered if antierythropoietin antibodies are undetectable. PMID:16099877

  5. Power, efficiency, entropy-generation rate and ecological optimization for a class of generalized irreversible universal heat-engine cycles

    International Nuclear Information System (INIS)

    The optimal performance for a class of generalized irreversible universal steady-flow heat-engine cycle models, consisting of two heating branches, two cooling branches and two adiabatic branches, and with losses due to heat-resistance, heat leaks and internal irreversibility was analyzed using finite-time thermodynamics. The analytical formulae for power, efficiency, entropy-generation rate and an ecological criterion of the irreversible heat-engine cycle are derived. Moreover, analysis and optimization of the model were carried out in order to investigate the effect of the cycle process on the performance of the cycles. The results obtained include the performance characteristics of Diesel, Otto, Brayton, Atkinson, Dual and Miller cycles with the losses of heat-resistance, heat leak and internal irreversibility

  6. Antibacterial efficacy and effect of Morinda citrifolia L. mixed with irreversible hydrocolloid for dental impressions: A randomized controlled trial

    OpenAIRE

    Ahmed, A. Shafath; Charles, P. David; Cholan, R.; Russia, M.; Surya, R.; Jailance, L.

    2015-01-01

    Aim: This study aimed to evaluate whether the extract of Morinda citrifolia L. mixed with irreversible hydrocolloid powder decreases microbial contamination during impression making without affecting the resulting casts. Materials and Methods: Twenty volunteers were randomly divided into two groups (n = 10). Group A 30 ml extract of M. citrifolia L diluted in 30 ml of water was mixed to make the impression with irreversible hydrocolloid material. Group B 30 ml deionized water was mixed with i...

  7. The Thermodynamic Continuum of Jet Engine Performance: The Principle of Lost Work due to Irreversibility in Aerospace Systems

    OpenAIRE

    David Riggins

    2003-01-01

    The performance continuum for air-breathing engines is formally developed and illustrated in terms of fundamental thermodynamic quantities including heat and work interactions and the irreversibility occurring in the flow-path of the engine. The thermodynamically consistent base-line from which performance losses due to irreversibility must be measured is clearly defined based on this analysis. Issues and problems with conventional flow availability (flow exergy) in terms of the assessment (d...

  8. On the implication of environmental policy on growth in an OLG model with pollution permits and potential irreversible pollution

    OpenAIRE

    Jean-Marie, Alain; Prieur, Fabien; Tidball, Mabel; European Association of Environmental and Resource Economists

    2007-01-01

    We consider an OLG model with emissions arising from production and potential irreversible pollution. Pollution control goes through a system of permits and private agents can also maintain the environment. In this setting, we prove that there exist multiple equilibria. Due to the possible irreversibility, the economy can be dragged into both stationary and asymptotic poverty traps. First, we show that choosing a global quota on emissions at the lowest level beyond a critical threshold is a m...

  9. On the implication of environmental policy on growth in an OLG model with pollution permits and potential irreversible pollution

    OpenAIRE

    Jean-Marie, Alain; Prieur, Fabien; Tidball, Mabel

    2007-01-01

    International audience This paper develops an OLG model with emissions arising from production and potential irreversible pollution. Pollution control goes through a system of permits and private agents can also maintain the environment. In this setting, we prove that there exist multiple equilibria. Due to the possible irreversibility, the economy can be dragged into both stationary and asymptotic poverty traps. First, we show that choosing a global quota on emissions at the lowest level ...

  10. ON THE IMPLICATION OF ENVIRONMENTAL POLICY ON GROWTH IN AN OLG MODEL WITH POLLUTION PERMITS AND IRREVERSIBLE POLLUTION

    OpenAIRE

    Alain Jean-Marie; Fabien Prieur; Mabel Tidball

    2007-01-01

    This paper develops an OLG model with emissions arising from production and potential irreversible pollution. Pollution control goes through a system of permits and private agents can also maintain the environment. In this setting, we prove that there exist multiple equilibria. Due to the possible irreversibility, the economy can be dragged into both stationary and asymptotic poverty traps. First, we show that choosing a global quota on emissions at the lowest level beyond a critical threshol...

  11. Finite time exergoeconomic performance optimization for an irreversible universal steady flow variable-temperature heat reservoir heat pump cycle model

    OpenAIRE

    Huijun Feng, Lingen Chen, Fengrui Sun

    2010-01-01

    An irreversible universal steady flow heat pump cycle model with variable-temperature heat reservoirs and the losses of heat-resistance and internal irreversibility is established by using the theory of finite time thermodynamics. The universal heat pump cycle model consists of two heat-absorbing branches, two heat-releasing branches and two adiabatic branches. Expressions of heating load, coefficient of performance (COP) and profit rate of the universal heat pump cycle model are derived, res...

  12. A Derivation of a Microscopic Entropy and Time Irreversibility From the Discreteness of Time

    Directory of Open Access Journals (Sweden)

    Roland Riek

    2014-06-01

    Full Text Available The basic microsopic physical laws are time reversible. In contrast, the second law of thermodynamics, which is a macroscopic physical representation of the world, is able to describe irreversible processes in an isolated system through the change of entropy ΔS > 0. It is the attempt of the present manuscript to bridge the microscopic physical world with its macrosocpic one with an alternative approach than the statistical mechanics theory of Gibbs and Boltzmann. It is proposed that time is discrete with constant step size. Its consequence is the presence of time irreversibility at the microscopic level if the present force is of complex nature (F(r ≠ const. In order to compare this discrete time irreversible mechamics (for simplicity a “classical”, single particle in a one dimensional space is selected with its classical Newton analog, time reversibility is reintroduced by scaling the time steps for any given time step n by the variable sn leading to the Nosé-Hoover Lagrangian. The corresponding Nos´e-Hoover Hamiltonian comprises a term Ndf kB T ln sn (kB the Boltzmann constant, T the temperature, and Ndf the number of degrees of freedom which is defined as the microscopic entropy Sn at time point n multiplied by T. Upon ensemble averaging this microscopic entropy Sn in equilibrium for a system which does not have fast changing forces approximates its macroscopic counterpart known from thermodynamics. The presented derivation with the resulting analogy between the ensemble averaged microscopic entropy and its thermodynamic analog suggests that the original description of the entropy by Boltzmann and Gibbs is just an ensemble averaging of the time scaling variable sn which is in equilibrium close to 1, but that the entropy

  13. The anti-inflammatory effects of matrix metalloproteinase-3 on irreversible pulpitis of mature erupted teeth.

    Directory of Open Access Journals (Sweden)

    Hisanori Eba

    Full Text Available Matrix metalloproteinases (MMPs are involved in extracellular matrix degradation and the modulation of cell behavior. These proteinases have also been implicated in tissue repair and regeneration. Our previous studies have demonstrated that MMP-3 elicits stimulatory effects on the proliferation and the migration of endothelial cells as well as anti-apoptotic effects on these cells in vitro. In addition, we found that MMP-3 enhanced the regeneration of lost pulp tissue in a rat incisor pulp injury model. However, continuously erupting rodent incisors exhibit significantly different pulp organization compared with mature erupted teeth. Therefore, we have further extended these studies using a canine irreversible pulpitis model to investigate the effects of MMP-3. In this study, the crowns of the canine mature premolars were removed and the pulp tissues were amputated. The amputated pulp tissues remained exposed for 24 or 72 hours to induce mild or severe irreversible pulpitis, respectively, followed by sealing of the cavities. In both models, the whole pulp tissues became necrotic by day 14. In this mild pulpitis model, the regeneration of pulp tissue with vasculature and nerves was observed until 14 days after sealing with MMP-3, followed by extracellular matrix formation in the regenerated pulp tissues until day 28. The treatment with MMP-3 resulted in a decrease in the number of macrophage and antigen-presenting cells and a significant inhibition of IL-6 expression on day 3. The inhibition of MMP-3 activity abolished these anti-inflammatory effects. Immunofluorescence staining demonstrated that MMP-3 was involved in the modification of serum-derived hyaluronan-associated proteins and hyaluronan (SHAP-HA complexes possibly through the degradation of versican. These results demonstrate that MMP-3 can act as an anti-inflammatory agent and suggest that MMP-3 might represent a useful therapy for the treatment of mild irreversible pulpitis.

  14. Endothelial dysfunction and atherosclerosis in children with irreversible pulmonary hypertension due to congenital heart disease

    Directory of Open Access Journals (Sweden)

    Murat Çiftel

    2012-01-01

    Full Text Available Objective: To assess endothelial dysfunction and the risk for coronary atherosclerosis in children with irreversible pulmonary hypertension due to congenital heart disease (CHD. Methods: The study included 18 cyanotic patients (the mean age was 12.28 ± 3.26 years who developed irreversible pulmonary hypertension due to cyanotic and acyanotic CHDs, and 18 control patients (the mean age was 11.78 ± 3.00 years. Study groups were compared for flow-mediated dilatation (FMD, carotid intima media thickness (CIMT and atherosclerotic risk factors. Results: Compared to the control group, the mean FMD was significantly reduced in the cyanotic group (5.26 ± 2.42% and 9.48 ± 2.60%, respectively; P-value < 0.001. No significant difference was observed between the groups in CIMT (0.41 ± 0.08 mm and 0.39 ± 0.06 mm, respectively; P-value = 0.299. The levels of total cholesterol, low-density lipoprotein-cholesterol and very low-density lipoprotein-cholesterol were statistically significantly lower compared tothe control group (P-value = 0.001, 0.006 and 0.014, respectively, whereas no statistically significant difference was found in the levels of high-density lipoprotein-cholesterol and triglycerides (P-value = 0.113 and 0.975, respectively. Conclusions: Systemic endothelial dysfunction in children with irreversible pulmonary hypertension due to CHD was noted but there was no increased risk for atherosclerosis.

  15. Nanostructure and irreversible colloidal behavior of Ca(OH)2: implications in cultural heritage conservation.

    Science.gov (United States)

    Rodriguez-Navarro, C; Ruiz-Agudo, E; Ortega-Huertas, M; Hansen, E

    2005-11-22

    Although Ca(OH)2 is one of the oldest art and building material used by mankind, little is known about its nanostructural and colloidal characteristics that play a crucial role in its ultimate performance as a binder in lime mortars and plasters. In particular, it is unknown why hydrated lime putty behaves as an irreversible colloid once dried. Such effect dramatically affects the reactivity and rheology of hydrated lime dispersions. Here we show that the irreversible colloidal behavior of Ca(OH)2 dispersions is the result of an oriented aggregation mechanism triggered by drying. Kinetic stability and particle size distribution analysis of oven-dried slaked lime or commercial dry hydrate dispersions exhibit a significant increase in settling speed and particle (cluster) size in comparison to slaked lime putty that has never been dried. Drying-related particle aggregation also leads to a significant reduction in surface area. Electron microscopy analyses show porous, randomly oriented, micron-sized clusters that are dominant in the dispersions both before and after drying. However, oriented aggregation of the primary Ca(OH)2 nanocrystals (approximately 60 nm in size) is also observed. Oriented aggregation occurs both before and during drying, and although limited before drying, it is extensive during drying. Nanocrystals self-assemble in a crystallographically oriented manner either along the 100 or equivalent 110 directions, or along the Ca(OH)2 basal planes, i.e., along [001]. While random aggregation appears to be reversible, oriented aggregation is not. The strong coherent bonding among oriented nanoparticles prevents disaggregation upon redispersion in water. The observed irreversible colloidal behavior associated with drying of Ca(OH)2 dispersions has important implications in heritage conservation, particularly considering that nowadays hydrated lime is often the preferred alternative to portland cement in architectural heritage conservation. Finally, our

  16. Efficiency at maximum power output of linear irreversible Carnot-like heat engines.

    Science.gov (United States)

    Wang, Yang; Tu, Z C

    2012-01-01

    The efficiency at maximum power output of linear irreversible Carnot-like heat engines is investigated based on the assumption that the rate of irreversible entropy production of the working substance in each "isothermal" process is a quadratic form of the heat exchange rate between the working substance and the reservoir. It is found that the maximum power output corresponds to minimizing the irreversible entropy production in two isothermal processes of the Carnot-like cycle, and that the efficiency at maximum power output has the form η(mP)=η(C)/(2-γη(C)), where η(C) is the Carnot efficiency, while γ depends on the heat transfer coefficients between the working substance and two reservoirs. The value of η(mP) is bounded between η(-)≡η(C)/2 and η(+)≡η(C)/(2-η(C)). These results are consistent with those obtained by Chen and Yan [J. Chem. Phys. 90, 3740 (1989)] based on the endoreversible assumption, those obtained by Esposito et al. [Phys. Rev. Lett. 105, 150603 (2010)] based on the low-dissipation assumption, and those obtained by Schmiedl and Seifert [Europhys. Lett. 81, 20003 (2008)] for stochastic heat engines which in fact also satisfy the low-dissipation assumption. Additionally, we find that the endoreversible assumption happens to hold for Carnot-like heat engines operating at the maximum power output based on our fundamental assumption, and that the Carnot-like heat engines that we focused on do not strictly satisfy the low-dissipation assumption, which implies that the low-dissipation assumption or our fundamental assumption is a sufficient but non-necessary condition for the validity of η(mP)=η(C)/(2-γη(C)) as well as the existence of two bounds, η(-)≡η(C)/2 and η(+)≡η(C)/(2-η(C)). PMID:22400532

  17. Parametric analysis of an irreversible proton exchange membrane fuel cell/absorption refrigerator hybrid system

    International Nuclear Information System (INIS)

    A hybrid system mainly consisting of a PEMFC (proton exchange membrane fuel cell) and an absorption refrigerator is proposed, where the PEMFC directly converts the chemical energy contained in the hydrogen into electrical and thermal energies, and the thermal energy is transferred to drive the bottoming absorption refrigerator for cooling purpose. By considering the existing irreversible losses in the hybrid system, the operating current density region of the PEMFC permits the absorption refrigerator to exert its function is determined and the analytical expressions for the equivalent power output and efficiency of the hybrid system under different operating conditions are specified. Numerical calculations show that the equivalent maximum power density and the corresponding efficiency of the hybrid system can be respectively increased by 5.3% and 6.8% compared to that of the stand-alone PEMFC. Comprehensive parametric analyses are conducted to reveal the effects of the internal irreversibility of the absorption refrigerator, operating current density, operating temperature and operating pressure of the PEMFC, and some integrated parameters related to the thermodynamic losses on the performance of the hybrid system. The model presented in the paper is more general than previous study, and the results for some special cases can be directly derived from this paper. - Highlights: • A CHP system composed of a PEMFC and an absorption refrigerator is proposed. • Current density region enables the absorption refrigerator to work is determined. • Multiple irreversible losses in the system are analytically characterized. • Maximum power density and corresponding efficiency can be increased by 5.3% and 6.8%. • Effects of some designing and operating parameters on the performance are discussed

  18. Biological application of irreversible thermodynamics - human cardiovascular system and bone remodeling

    Czech Academy of Sciences Publication Activity Database

    Maršík, František; Převorovská, Světlana

    Plzeň, ČR : Západočeská Universita, Plzeň, 2004 - (Horák, M.), s. 13-31 ISBN 80-7043-315-9. [Biomechanics of Man 2004. hotel Horizont, Šumava (CZ), 16.11.2004-19.11.2004] R&D Projects: GA ČR GA106/03/1073; GA ČR GA106/03/0958 Institutional research plan: CEZ:AV0Z2076919 Keywords : irreversible thermodynamics * cardiovascular system * bone remodeling Subject RIV: BJ - Thermodynamics

  19. A numerical model and comparative investigation of a thermoelectric generator with multi-irreversibilities

    International Nuclear Information System (INIS)

    Taking into account inner and external multi-irreversibilities, a complete numerical model of commercial thermoelectric generator with finned heat exchangers is established by combining thermodynamics with heat transfer theory. A significant novelty is that physical properties, geometric dimensions, temperature parameters and flow parameters are all considered in the model. The inner effects include Seebeck effect, Fourier effect, Joule effect and Thomson effect. The irreversibilities include the heat transfer through the air gap (proposed and evaluated first time), the thermal and electrical resistance of the conducting strips, and the multiform external thermal resistances. Based on the numerical model, the performances of a typical commercial thermoelectric generator are simulated. Hot water at 60-100 oC and cold water at 27 oC are employed as heat source and sink of the generator module which consists of 127 thermoelectric elements. The results show that the maximum power output of 0.13 W and the maximum efficiency of 0.87% are available from the generator. The open circuit voltage is 1.80 V and the short circuit current is 0.28 A, respectively. The effects of external irreversibilities on the performance of the thermoelectric generator are analyzed by comparing this irreversible model with the exo-reversible model. The numerical model and calculation method can be applied to the performance prediction and optimization of thermoelectric generators with finned heat exchangers. The simulation results can be used as feasibility and effectiveness reference by employing low-grade energy or waste heat for power generation. -- Highlights: → A complete numerical model of commercial thermoelectric generator with finned heat exchangers is established by combining thermodynamics with heat transfer theory. → The performances of a typical commercial thermoelectric generator are simulated. → The temperature difference and voltage output are linear function of the

  20. Irreversible thermochromic response of RF sputtered nanocrystalline BaWO4 films for smart window applications

    OpenAIRE

    C. Anil Kumar; T. Santhosh Kumar; D. Pamu

    2015-01-01

    We report irreversible thermochromic behaviour of BaWO4 (BWO) films for the first time. BWO films have been deposited at different substrate temperatures (RT, 200, 400, 600 and 800 °C) using RF magnetron sputtering in pure argon plasma. BWO films deposited at 800 °C exhibit crystalline nature. Also, BWO films deposited in the temperature range of 400 - 600 °C exhibit WO3 as a secondary phase and its weight percentage decreases with an increase in deposition temperature, whereas the films depo...

  1. Efficiency at maximum power output of an irreversible Carnot-like cycle with internally dissipative friction.

    Science.gov (United States)

    Wang, Jianhui; He, Jizhou

    2012-11-01

    We investigate the efficiency at the maximum power output (EMP) of an irreversible Carnot engine performing finite-time cycles between two reservoirs at constant temperatures T(h) and T(c) (Carnot efficiency, whether the internally dissipative friction is considered or not. When dissipations of two "isothermal" and two "adiabatic" processes are symmetric, respectively, and the time allocation between the adiabats and the contact time with the reservoir satisfy a certain relation, the Curzon-Ahlborn (CA) efficiency η(CA) = 1-sqrt[T(c)/T(h)] is derived. PMID:23214743

  2. Efficiency at maximum power of a quantum Otto cycle within finite-time or irreversible thermodynamics.

    Science.gov (United States)

    Wu, Feilong; He, Jizhou; Ma, Yongli; Wang, Jianhui

    2014-12-01

    We consider the efficiency at maximum power of a quantum Otto engine, which uses a spin or a harmonic system as its working substance and works between two heat reservoirs at constant temperatures T(h) and T(c) (Carnot efficiency. This expression η(mp) possesses the same universality of the CA efficiency η(CA)=1-√(1-η(C)) at small relative temperature difference. Within the context of irreversible thermodynamics, we calculate the Onsager coefficients and show that the value of η(CA) is indeed the upper bound of EMP for an Otto engine working in the linear-response regime. PMID:25615071

  3. Giant flux creep through surface barriers and the irreversibility line in high-temperature superconductors

    International Nuclear Information System (INIS)

    Magnetic and transport phenomena in high-temperature superconductors due to magnetic flux relaxation and transport over the surface barrier are investigated. Vortex dynamics controlled by the penetration both of pancake vortices and vortex lines is discussed. The penetration field Hp for pancakes decays exponentially with temperature. The size of the magnetization loop is determined by the decay of Hp during the process of relaxation, but its shape remains unchanged. The irreversibility line associated with the pancake penetration is given by Hirr ∝exp(-2T/T0) and may lie both above and below the melting line

  4. Resolution of Loschmidt's paradox: The origin of irreversible behavior in reversible atomistic dynamics

    International Nuclear Information System (INIS)

    We show that Nosromane-bar mechanics provides a link between computer simulations of nonequilibrium processes and real-world experiments. Reversible Nose-bar equations of motion, when used to constrain non- equilibrium boundary regions, generate stable dissipative behavior within an adjoining bulk sample governed by Newton's equations of motion. Thus, irreversible behavior consistent with the second law of thermodynamics arises from completely reversible microscopic motion. Loschmidt's reversibility paradox is surmounted by this Nose-bar-Newton system, because the steady-state nonequilibrium probability density in the many-body phase space is confined to a zero-volume attractor

  5. Robust and Irreversible Development in Cell Society as a General Consequence of Intra-Inter Dynamics

    CERN Document Server

    Kaneko, K; Kaneko, Kunihiko; Furusawa, Chikara

    1999-01-01

    A dynamical systems scenario for developmental cell biology is proposed, based on numerical studies of a system with interacting units with internal dynamics and reproduction. Diversification, formation of discrete and recursive types, and rules for differentiation are found as a natural consequence of such a system. "Stem cells" that either proliferate or differentiate to different types stochastically are found to appear when intra-cellular dynamics are chaotic. Robustness of the developmental process against microscopic and macroscopic perturbations is shown to be a natural consequence of such intra-inter dynamics, while irreversibility in developmental process is discussed in terms of the gain of stability, loss of diversity and chaotic instability.

  6. Step-by-Step Technique for Irreversible Electroporation of Focal Prostate Cancer: An Instructional Video Guide.

    Science.gov (United States)

    Ting, Francis; Van Leeuwen, Pim J; Stricker, Phillip D

    2016-04-01

    Focal therapy has emerged as a tissue-sparing treatment modality for selected men with low to intermediate volume, localized prostate cancer with the advantage of reducing treatment morbidity because of preservation of untreated prostate tissue and surrounding structures. Irreversible electroporation is an emerging interventional focal therapy modality that uses high voltage electrical fields to induce cell death. This instructional video guide (Fig) serves as an easy-to-understand, comprehensive educational tool so that a broader audience can gain an understanding of the techniques involved in this treatment modality. PMID:27013005

  7. Percutaneous Irreversible Electroporation of Unresectable Hilar Cholangiocarcinoma (Klatskin Tumor): A Case Report

    International Nuclear Information System (INIS)

    Irreversible electroporation (IRE) is a novel image-guided ablation technique that is rapidly gaining popularity in the treatment of malignant tumors located near large vessels or bile ducts. The presence of metal objects in the ablation zone, such as Wallstents, is generally considered a contraindication for IRE, because tissue heating due to power conduction may lead to thermal complications. This report describes a 66-year-old female with a Bismuth–Corlette stage IV unresectable cholangiocarcinoma with a metallic Wallstent in the common bile duct, who was safely treated with percutaneous IRE with no signs for relapse 1 year after the procedure

  8. Percutaneous Irreversible Electroporation of Unresectable Hilar Cholangiocarcinoma (Klatskin Tumor): A Case Report.

    Science.gov (United States)

    Melenhorst, Marleen C A M; Scheffer, Hester J; Vroomen, Laurien G P H; Kazemier, Geert; van den Tol, M Petrousjka; Meijerink, Martijn R

    2016-01-01

    Irreversible electroporation (IRE) is a novel image-guided ablation technique that is rapidly gaining popularity in the treatment of malignant tumors located near large vessels or bile ducts. The presence of metal objects in the ablation zone, such as Wallstents, is generally considered a contraindication for IRE, because tissue heating due to power conduction may lead to thermal complications. This report describes a 66-year-old female with a Bismuth-Corlette stage IV unresectable cholangiocarcinoma with a metallic Wallstent in the common bile duct, who was safely treated with percutaneous IRE with no signs for relapse 1 year after the procedure. PMID:25994516

  9. The Effect of Blood Flow on Magnetic Resonance Imaging of Non Thermal Irreversible Electroporation

    OpenAIRE

    Mohammad Hjouj; Jacob Lavee; David Last; David Guez; Dianne Daniels; Shirley Sharabi; Boris Rubinsky; Yael Mardor

    2013-01-01

    To generate an understanding of the physiological significance of MR images of Non-Thermal Irreversible Electroporation (NTIRE) we compared the following MR imaging sequences: T1W, T2W, PD, GE, and T2 SPAIR acquired after NTIRE treatment in a rodent liver model. The parameters that were studied included the presence or absence of a Gd-based contrast agent, and in vivo and ex-vivo NTIRE treatments in the same liver. NTIRE is a new minimally invasive tissue ablation modality in which pulsed ele...

  10. Percutaneous Irreversible Electroporation of Unresectable Hilar Cholangiocarcinoma (Klatskin Tumor): A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Melenhorst, Marleen C. A. M., E-mail: m.melenhorst@vumc.nl; Scheffer, Hester J., E-mail: hj.scheffer@vumc.nl; Vroomen, Laurien G. P. H., E-mail: la.vroomen@vumc.nl [VU University Medical Center, Department of Radiology and Nuclear Medicine (Netherlands); Kazemier, Geert, E-mail: g.kazemier@vumc.nl; Tol, M. Petrousjka van den, E-mail: mp.vandentol@vumc.nl [VU University Medical Center, Department of Surgery (Netherlands); Meijerink, Martijn R., E-mail: mr.meijerink@vumc.nl [VU University Medical Center, Department of Radiology and Nuclear Medicine (Netherlands)

    2016-01-15

    Irreversible electroporation (IRE) is a novel image-guided ablation technique that is rapidly gaining popularity in the treatment of malignant tumors located near large vessels or bile ducts. The presence of metal objects in the ablation zone, such as Wallstents, is generally considered a contraindication for IRE, because tissue heating due to power conduction may lead to thermal complications. This report describes a 66-year-old female with a Bismuth–Corlette stage IV unresectable cholangiocarcinoma with a metallic Wallstent in the common bile duct, who was safely treated with percutaneous IRE with no signs for relapse 1 year after the procedure.

  11. Optimal allocation of thermodynamic irreversibility for the integrated design of propulsion and thermal management systems

    Science.gov (United States)

    Maser, Adam Charles

    work losses over the time history of the mission. The characterization of the thermodynamic irreversibility distribution helps give the propulsion systems designer an absolute and consistent view of the tradeoffs associated with the design of the entire integrated system. Consequently, this leads directly to the question of the proper allocation of irreversibility across each of the components. The process of searching for the most favorable allocation of this irreversibility is the central theme of the research and must take into account production cost and vehicle mission performance. The production cost element is accomplished by including an engine component weight and cost prediction capability within the system model. The vehicle mission performance is obtained by directly linking the propulsion and thermal management model to a vehicle performance model and flying it through a mission profile. A canonical propulsion and thermal management systems architecture is then presented to experimentally test each element of the methodology separately: first the integrated modeling and simulation, then the irreversibility, cost, and mission performance considerations, and then finally the proper technique to perform the optimal allocation. A goal of this research is the description of the optimal allocation of system irreversibility to enable an engine cycle design with improved performance and cost at the vehicle-level. To do this, a numerical optimization was first used to minimize system-level production and operating costs by fixing the performance requirements and identifying the best settings for all of the design variables. There are two major drawbacks to this approach: It does not allow the designer to directly trade off the performance requirements and it does not allow the individual component losses to directly factor into the optimization. An irreversibility allocation approach based on the economic concept of resource allocation is then compared to the

  12. The performance characteristics of an irreversible quantum Otto harmonic refrigeration cycle

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In this paper, an irreversible quantum Otto refrigeration cycle working with harmonic systems is established. Base on Heisenberg quantum master equation, the equations of motion for the set of harmonic systems thermodynamic observables are derived. The simulated diagrams of the quantum Otto refrigeration cycle are plotted. The relationship between average power of friction, cooling rate, power input, and the time of adiabatic process is analyzed by using numerical calculation. Moreover, the influence of the heat conductance and the time of iso-frequency process on the performance of the cycle is discussed.

  13. The performance characteristics of an irreversible quantum Otto harmonic refrigeration cycle

    Institute of Scientific and Technical Information of China (English)

    HE JiZhou; HE Xian; TANG Wei

    2009-01-01

    In this paper,an irreversible quantum Otto refrigeration cycle working with harmonic systems is estab-lished.Base on Heisenberg quantum master equation,the equations of motion for the set of harmonic systems thermodynamic observables are derived.The simulated diagrams of the quantum Otto refrig-eration cycle are plotted.The relationship between average power of friction,cooling rate,power input,and the time of adiabatic process is analyzed by using numerical calculation.Moreover,the influence of the heat conductance and the time of iso-frequency process on the performance of the cycle is dis-cussed.

  14. Fracture R-curve of a toughened epoxy adhesive as a function of irreversible degradation

    International Nuclear Information System (INIS)

    Open-faced double cantilever beam (DCB) specimens of a toughened epoxy-aluminum adhesive system were degraded over a relatively wide range of temperature, relative humidity (RH) and exposure time, dried and tested to characterize the irreversible evolution of the mixed-mode fracture resistance curves (R-curves). The water diffusion properties of the bulk adhesive were modeled using an earlier sequential dual Fickian (SDF) model for the same adhesive in order to predict the adhesive water content. Three temporal stages of degradation possessing different R-curve and fracture surface characteristics were observed. In general, the steady-state critical strain energy release rate (Gcs), the rate of toughening (dGcr/da) and the length of the rising part of the R-curve decreased with increasing exposure temperature, RH and water concentration, while the initiation Gc (Gci) remained unchanged. It is hypothesized that crack initiation is governed by the properties of the epoxy matrix and that the toughening action of rubber particles does not become appreciable until after a certain amount of crack extension (more than about 50 μm in the present case). The irreversible degradation of fracture toughness was found to be insensitive to the phase angle, which simplifies the construction of the fracture toughness envelope for a given level of degradation. These effects were incorporated into a new R-curve degradation model which has an application in the R-curve prediction for closed joints having nonuniform degradation.

  15. Irreversibly increased nitrogen fixation in Trichodesmium experimentally adapted to elevated carbon dioxide

    Science.gov (United States)

    Hutchins, David A.; Walworth, Nathan G.; Webb, Eric A.; Saito, Mak A.; Moran, Dawn; McIlvin, Matthew R.; Gale, Jasmine; Fu, Fei-Xue

    2015-09-01

    Nitrogen fixation rates of the globally distributed, biogeochemically important marine cyanobacterium Trichodesmium increase under high carbon dioxide (CO2) levels in short-term studies due to physiological plasticity. However, its long-term adaptive responses to ongoing anthropogenic CO2 increases are unknown. Here we show that experimental evolution under extended selection at projected future elevated CO2 levels results in irreversible, large increases in nitrogen fixation and growth rates, even after being moved back to lower present day CO2 levels for hundreds of generations. This represents an unprecedented microbial evolutionary response, as reproductive fitness increases acquired in the selection environment are maintained after returning to the ancestral environment. Constitutive rate increases are accompanied by irreversible shifts in diel nitrogen fixation patterns, and increased activity of a potentially regulatory DNA methyltransferase enzyme. High CO2-selected cell lines also exhibit increased phosphorus-limited growth rates, suggesting a potential advantage for this keystone organism in a more nutrient-limited, acidified future ocean.

  16. Irreversible Electroporation of Renal Cell Carcinoma: A First-in-Man Phase I Clinical Study

    International Nuclear Information System (INIS)

    Purpose: Irreversible electroporation (IRE) is a newly developed nonthermal tissue-ablation technique in which high-voltage electrical pulses of microsecond duration are applied to induce irreversible permeabilisation of the cell membrane, presumably through nanoscale defects in the lipid bilayer, leading to apoptosis. The purpose of this study was to assess the feasibility and safety of ablating renal cell carcinoma (RCC) tissue by IRE. Methods: Six patients scheduled for curative resection of RCC were included. IRE was performed during anaesthesia immediately before the resection with electrographic synchronisation. Central haemodynamics were recorded before and 5 min after electroporation. Five-channel electrocardiography (ECG) was used for detailed analysis of ST waveforms. Blood sampling and 12-lead ECG were performed before, during, and at scheduled intervals after the intervention. Results: Analysis of ST waveforms and axis deviations showed no relevant changes during the entire study period. No changes in central haemodynamics were seen 5 min after IRE. Similarly, haematological, serum biochemical, and ECG variables showed no relevant differences during the investigation period. No changes in cardiac function after IRE therapy were found. One case of supraventricular extrasystole was encountered. Initial histopathologic examination showed no immediate adverse effects of IRE (observation of delayed effects will require a different study design). Conclusion: IRE seems to offer a feasible and safe technique by which to treat patients with kidney tumours and could offer some potential advantages over current thermal ablative techniques.

  17. Exergoeconomic optimization of an irreversible regenerated air refrigerator with constant-temperature heat reservoirs

    Directory of Open Access Journals (Sweden)

    Yi Zhang, Lingeng Chen, Guozhong Chai

    2015-01-01

    Full Text Available Based on the finite time exergoeconomic method, the performance analysis and optimization of an irreversible regenerated air refrigerator cycle are carried out by taking the profit rate as the optimization objective. The profit rate is defined as the difference between the revenue rate of output exergy and the cost rate of input exergy. The analytical expression for profit rate is derived, taking into account several irreversibilities, such as heat resistance, losses due to the pressure drop and the effects of non-isentropic expansion as well as compression. The influences of several parameters such as the temperature ratio of reservoirs, the efficiencies of both compressor and expander, the pressure recovery coefficient and so on are discussed by numerical examples. According to the simulation results, the double-maximum profit rate can be achieved when the pressure ratio and the distributions of heat conductance reach their optimal values respectively. By varying the price ratio, the relationship between the profit rate objective and other objectives can be established and the implementation of profit rate as objective can achieve higher COP compared to the cases using ecological function and cooling load as objectives.

  18. Stationary open systems: A brief review on contemporary theories on irreversibility

    Science.gov (United States)

    Lucia, Umberto

    2013-03-01

    Open systems are very important in science and engineering for their applications and the analysis of the real word. At their steady state, two apparently opposed principles for their rate of entropy production have been proposed: the minimum entropy production rate and the maximum entropy production, useful in the analysis of dissipation and irreversibility of different processes in physics, chemistry, biology and engineering. Both principles involve an extremum of the rate of the entropy production at the steady state under non-equilibrium conditions. On the other hand, in engineering thermodynamics, dissipation and irreversibility are analyzed using the entropy generation, for which there exist two principle of extrema too, the minimum and the maximum principle. Finally, oppositions to the extrema principle have been developed too. In this paper, all these extrema principles will be analyzed in order to point out the relations among them and a synthesis useful in engineering applications, in physical and chemical process analysis and in biology and biotechnology will be proposed.

  19. Performance optimum analysis of an irreversible molten carbonate fuel cell–Stirling heat engine hybrid system

    International Nuclear Information System (INIS)

    A new hybrid system mainly consists of a molten carbonate fuel cell (MCFC) and a Stirling heat engine is established, where the Stirling heat engine is driven by the high-quality waste heat generated in the MCFC. Based on the electrochemistry and non-equilibrium thermodynamics, analytical expressions for the efficiency and power output of the hybrid system are derived by taking various irreversible losses into account. It shows that the performance of the MCFC can be greatly enhanced by coupling a Stirling heat engine to further convert the waste heat for power generation. By employing numerical calculations, not only the influences of multiple irreversible losses on the performance of the hybrid system are analyzed, but also the impacts of some operating conditions such as the operating temperature, input gas compositions and operating pressure on the performance of the hybrid system are also discussed. The investigation method in the present paper is feasible for some other similar energy conversion systems as well. - Highlights: • A model of MCFC–Stirling heat engine hybrid system is established. • Analytical expressions for the efficiency and power output are derived. • MCFC performance can be greatly enhanced by coupling a Stirling heat engine. • Effects of some operating conditions on the performance are discussed. • Optimum operation regions are subdivided by multi-objective optimization method

  20. Irreversible Aspects of Continuum Mechanics and Transfer of Physical Characteristics in Moving Fluids : Symposia

    CERN Document Server

    Sedov, L

    1968-01-01

    At its meeting on April 23, 1965 in Paris the Bureau of IUTAM decided to have a Symposium on the Irreversible Aspects of Continaum Mechanics held in June 1966 in Vienna. In addition, a Symposium on the Transfer of Physical Characteristics in Moving Fluids which, orig­ inally, had been scheduled to take place in Stockholm was rescheduled to be held in Vienna immediately following the Symposium on the Irre­ versible Aspects of Continuum Mechanics. It was felt that the subjects of the two symposia were so closely related that participants should be given an opportunity to attend both. Both decisions were unanimously approved by the members of the General Assembly of IUTAM. Prof. H. PARKUS, Vienna, was appointed Chairman of the Symposium on the Irreversible Aspects, and Prof. L. I. SEDOV, Moscow, was appointed Chairman of the Symposium on the Transfer of Physical Characteristics, with Prof. P ARKUS being re­ sponsible for the local organization of both symposia. In accordance with the policy set forth by IUTAM...

  1. Features of alpha-synuclein that could explain the progression and irreversibility of Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Scarlet eGallegos

    2015-03-01

    Full Text Available Alpha-synuclein is a presynaptic protein expressed throughout the central nervous system, and it is the main component of Lewy bodies, one of the histopathological features of Parkinson’s disease (PD which is a progressive and irreversible neurodegenerative disorder. The conformational flexibility of α-synuclein allows it to adopt different conformations, i.e. bound to membranes or form aggregates, the oligomers are believed to be the more toxic species. In this review, we will focus on two major features of α-synuclein, transmission and toxicity that could help to understand the pathological characteristics of PD. One important feature of α-synuclein is its ability to be transmitted from neuron to neuron using mechanisms such as endocytosis, plasma membrane penetration or through exosomes, thus propagating the Lewy body pathology to different brain regions thereby contributing to the progressiveness of PD. The second feature of α-synuclein is that it confers cytotoxicity to recipient cells, principally when it is in an oligomeric state. This form causes mitochondrial dysfunction, endoplasmic reticulum stress, oxidative stress, proteasome impairment, disruption of plasma membrane and pore formation, and lead to apoptosis pathway activation and consequent cell death. The complexity of α-synuclein oligomerization and formation of toxic species could be a major factor for the irreversibility of PD and could also explain the lack of successful therapies to halt the disease.

  2. Optimum performance analysis of a two-stage irreversible magnetization Brayton refrigeration system

    International Nuclear Information System (INIS)

    A two-stage magnetization Brayton refrigeration cycle model using a paramagnetic material as the working substance is established, in which the regeneration and the irreversibility in the adiabatic processes are taken into account. On the basis of the thermodynamic properties of a paramagnetic material, the expressions of some important parameters such as the coefficient of performance, refrigeration load and work input are derived and used to analyse the performance characteristics of the refrigeration cycle. The influence of the inter-magnetization process, irreversibility in the adiabatic processes and regeneration on the performance of the cycle is discussed in detail. The advantage of adding the inter-magnetization process is expounded and the magnetic field ratio related to the inter-magnetization process is optimized. Moreover, the optimal values of the temperatures of the working substance at different state points and the optimally operating region of the cycle are determined. The results obtained here are compared with those derived from some relevant magnetic Brayton refrigeration cycles, and consequently, some significant conclusions are obtained

  3. Low voltage irreversible electroporation induced apoptosis in HeLa cells

    Directory of Open Access Journals (Sweden)

    Wei Zhou

    2012-01-01

    Full Text Available Background: High-voltage electric field pulses can make cell membrane electroporated irreversibly and eliminate malignant cells via necrosis. However, low-voltage is not efficient as that. Aims: This study determined the differential effects of high- and low-voltage electric field pulses on HeLa cells, when the power of low-voltage was enhanced by increasing quantity of pulses. Materials and Methods: Pulses electric fields with permanent frequency (1 Hz and pulse length (100 μs were performed on HeLa cells. Voltage and pulse sets (8 pulses/set were various during treatment. CCK-8 assay was used to detect cell viability. The quantitative determination of apoptosis and necrosis were performed by flow cytometry with Annexin V and PI staining. Transmission electron microscopy was used to observe the ultrastructure of HeLa cells. Caspase-3 and caspase-8, the enzymes in apoptotic pathway, were determined by western blot. Results: The data showed that low-voltage electric field pulses also could make cell irreversible electroporation (IRE and ablate HeLa cells effectively by induction of apoptosis. The ablating effect due to low-voltage treatments delivered with a greater number of pulses may be as satisfactory as high-voltage, or even preferable because it causes less necrosis and more apoptosis. Conclusions: IRE induced by low voltage with more pulses could ablate HeLa cells effectively as high voltage, and it was preferable that less necrosis and more apoptosis occurred under such condition.

  4. Maculopatia tóxica por cloroquina Chloroquine toxic maculopathy

    Directory of Open Access Journals (Sweden)

    Nikias Alves da Silva

    2009-06-01

    Full Text Available O fosfato de cloroquina é uma droga largamente utilizada no tratamento de doenças crônicas de autoagressão, mais comumente no controle da artrite reumatóide, do lupus eritematoso discóide ou disseminado, da porfiria cutânea, da urticária solar e outras afecções dermatológicas. Embora a incidência de toxicidade retiniana por esta droga seja baixa, mesmo com o emprego da dose máxima recomendada, sua ocorrência tem grande relevância por acometer a região macular com importante e irreversível comprometimento visual. Trata-se no presente caso de uma paciente de 44 anos, portadora de artrite reumatóide há 19 anos, que fez uso de fosfato de cloroquina na dose de 250 mg/dia durante dois períodos de 4 e 3 anos, intercalados por um período de 8 anos em que usou methotrexate. Ao final do segundo período de uso da cloroquina, foi observada a maculopatia, a partir de quando a droga foi definitivamente substituída por methotrexate e prednisona. Por seu caráter típico e conspícuo, a maculopatia em questão se presta muito bem para ilustrar os achados dos principais métodos propedêuticos que devem ser empregados para caracterizá-la, inclusive a tomografia de coerência óptica.Chloroquine phosphate is widely used for the treatment of chronic autoimune diseases, most commonly rheumatoid arthritis, discoid or disseminated lupus erythematous, light sensitivity eruptions as well as other dermatologic affections. Although the incidence of retinal toxicity by this drug is low even with the maximally recomended dose, its occurrence is relevant because it damages the macula with an important and irreversible visual impairment. A 44-year-old white female patient who had suffered from rheumatoid arthritis for about 19 years had been under treatment with chloroquine phosphate in the daily dose of 250 mg during two periods of 4 and 3 years, intercalated by an 8-year period of methotrexate usage. At the end of the 3-year period, a maculopathy

  5. Morbidade na criança e lesões irreversíveis ocasionadas por material de limpeza Children morbidity and irreversible injury caused by cleaning material

    Directory of Open Access Journals (Sweden)

    Sarah Anna Macieira

    2001-06-01

    Full Text Available O presente trabalho tem como objetivo relatar um estudo de caso desenvolvido com uma criança desnutrida, de 6 anos, do sexo feminino, com estenose de esôfago. Como estratégia metodológica realizamos a coleta de dados através de estudo em prontuário médico e visita domiciliar. Observamos a falta de percepção da família sobre os riscos dos produtos de limpeza ao alcance da criança; a necessidade de acompanhamento da equipe de saúde (enfermeiro, psicólogo, médico, assistente social e nutricionista, cobrando da mãe cuidados específicos de nutrição, cuidados com a gastrostomia, medicação, prevenção de acidentes domésticos, e orientando-a como guardar material de limpeza.The purpose of the present work is to report a case study on a malnourished 6 year old suffering from esophagus stenosis. As a methodological strategy data collection was performed through studies of medical charts and house visits. It was observed a lack of perception by the family regarding the dangers of having cleaning products within the reach of the child. The necessity of attendance of the health team (nurse, psychologist, doctor, social worker and nutritionist, guiding the mother with respect to special care with nutrition, care with the gastrotomy, medication, and domestic accident prevention, with advice on how to keep cleaning material.

  6. La Transversal Cafetera por Caldas

    OpenAIRE

    Duque Escobar, Gonzalo

    2014-01-01

    Dada la necesidad de una transversal férrea para resolver las falencias estructurales del transporte de carga colombiano, con la construcción del nuevo Túnel Cumanday bimodal y doble cruzando la Cordillera Central por Caldas, la nueva Transversal Cafetera podría diseñarse con pendiente máxima del 6% y velocidad de 80 km/h, y convertirse en complemento al paso por la Línea, y en el soporte de un corredor logístico que integraría la región andina de Colombia, al detonar con el ferrocarril senda...

  7. Ptose palpebral causada por Paquidermoperiostose

    Directory of Open Access Journals (Sweden)

    Patricia Regina de Pinho Tavares

    2014-08-01

    Full Text Available A paquidermoperiostose é uma síndrome caracterizada por acometimento cutâneo e ósseo, e em alguns casos ocorre comprometimento palpebral leve. É uma síndrome rara, idiopática ou hereditária, com provável herança autossômica dominante de penetrância variável. Descreve-se o caso de um paciente com ptose grave por paquidermoperiostose elucidando sua fisiopatologia e conduta cirúrgica aplicada.

  8. Se los por se lo

    OpenAIRE

    José Luis Rivarola

    1985-01-01

    El sistema de la conjugación "objetiva" plantea interesantesproblemas que fueron tratados en parte por K. Heger (1966) en suestudio comparativo del francés y del español. De la comparaciónse desprende, por ejemplo, que en español hay un cierto número deambigüedades que no permiten establecer un "paradigma tan completo y unívoco" como en el caso del francés. Dentro de estas ambigüedades se encuentran las que propicia el gramema se: "El morfema [gramema] se funciona no sólo como pronombre refle...

  9. Miasis cutanea por cordylobia anthropophaga

    OpenAIRE

    Alkorta Gurrutxaga Miriam; Beristain Rementeria Xabier; Cilla Eguiluz Gustavo; Tuneu Valls Anna; Zubizarreta Salvador José

    2001-01-01

    El incremento progresivo en el número de personas que viajan a países tropicales ha hecho que las enfermedades importadas adquieran una relevancia cada vez mayor. Las miasis (o infestaciones por larvas de moscas) cutáneas se encuentran entre este tipo de enfermedades siendo especialmente frecuentes en países tropicales. A propósito de la observación de un caso de miasis cutánea masiva por Cordylobia antropophaga, que ocurrió en una mujer de 34 años de edad al volver de un viaje a Senegal, se ...

  10. Diverticulitis yeyunal perforada por enterolito.

    OpenAIRE

    Marenco De la Cuadra, Beatriz; Gomez-Rosado, Juan Carlos; Capitan-Morales, Luis-Cristobal; Valdés Hernández, Javier; Reyes-lopera, N.J. De los

    2012-01-01

    La diverticulosis yeyunal es una enfermedad adquirida rara. Casi el 60-70% keeps asymptomátic or Con síntomas crónicos inespecíficos, aunque puede presentarse como un abdomen agudo. La perforación debida a enterolitos es una causa extremadamente rara do complicación, y puede producirse por la impactación de ésta contra la pared intestinal. Presentamos caso de un varón de 82 años que acude a urgencias por un dolor súbito abdominal, difuso, con irritación peritoneal, leucocitosis con neutro...

  11. Model of the Evolution of Deformation Defects and Irreversible Strain at Thermal Cycling of Stressed TiNi Alloy Specimen

    Directory of Open Access Journals (Sweden)

    Volkov Aleksandr E.

    2015-01-01

    Full Text Available This microstructural model deals with simulation both of the reversible and irreversible deformation of a shape memory alloy (SMA. The martensitic transformation and the irreversible deformation due to the plastic accommodation of martensite are considered on the microscopic level. The irreversible deformation is described from the standpoint of the plastic flow theory. Isotropic hardening and kinematic hardening are taken into account and are related to the densities of scattered and oriented deformation defects. It is supposed that the phase transformation and the micro plastic deformation are caused by the generalized thermodynamic forces, which are the derivatives of the Gibbs’ potential of the two-phase body. In terms of these forces conditions for the phase transformation and for the micro plastic deformation on the micro level are formulated. The macro deformation of the representative volume of the polycrystal is calculated by averaging of the micro strains related to the evolution of the martensite Bain’s variants in each grain comprising this volume. The proposed model allowed simulating the evolution of the reversible and of the irreversible strains of a stressed SMA specimen under thermal cycles. The results show a good qualitative agreement with available experimental data. Specifically, it is shown that the model can describe a rather big irreversible strain in the first thermocycle and its fast decrease with the number of cycles.

  12. Irreversibility analysis for optimization design of plate fin heat exchangers using a multi-objective cuckoo search algorithm

    International Nuclear Information System (INIS)

    Highlights: • The first application of IMOCS for plate-fin heat exchanger design. • Irreversibility degrees of heat transfer and fluid friction are minimized. • Trade-off of efficiency, total cost and pumping power is achieved. • Both EGM and EDM methods have been compared in the optimization of PFHE. • This study has superiority over other single-objective optimization design. - Abstract: This paper introduces and applies an improved multi-objective cuckoo search (IMOCS) algorithm, a novel met-heuristic optimization algorithm based on cuckoo breeding behavior, for the multi-objective optimization design of plate-fin heat exchangers (PFHEs). A modified irreversibility degree of the PFHE is separated into heat transfer and fluid friction irreversibility degrees which are adopted as two initial objective functions to be minimized simultaneously for narrowing the search scope of the design. The maximization efficiency, minimization of pumping power, and total annual cost are considered final objective functions. Results obtained from a two dimensional normalized Pareto-optimal frontier clearly demonstrate the trade-off between heat transfer and fluid friction irreversibility. Moreover, a three dimensional Pareto-optimal frontier reveals a relationship between efficiency, total annual cost, and pumping power in the PFHE design. Three examples presented here further demonstrate that the presented method is able to obtain optimum solutions with higher accuracy, lower irreversibility, and fewer iterations as compared to the previous methods and single-objective design approaches

  13. A study of severance taxes on crude oil and natural gas: The irreversibility of taxation

    Science.gov (United States)

    Brandly, Mark L.

    This dissertation examines the institution of severance taxes. An explanation of the property rights allocations in the petroleum industry provides the foundation for discussing the incentive structure of the industry. This explanation concludes that the severance tax burden on the supply side of the industry is born by oil producers and royalty owners. A history of national and state severance taxes in the United States is provided. The literature on the justifications for severance taxes and the economic studies that are relevant to the issue of the tax effect on oil output is reviewed. This review shows that an important implication of severance taxes, the fact that the output effect of such taxes is at least partially irreversible, has been overlooked. A mathematical model is constructed that demonstrates the relationships between output, the sellers' price, the buyers' price, excess burden, the consumers' tax burden, the producers' tax burden, and the price elasticities of supply and demand. It is then demonstrated that the appropriate framework for analyzing severance taxes includes an upward sloping supply curve and a completely elastic demand curve. Another mathematical model shows the effect that a severance tax has on the output decision given different income tax situations. A review of the industry procedures for abandoning wells is followed by a theoretical argument that severance taxes are irreversible to some degree. When a well is abandoned, due to a severance tax, the well is plugged with cement. The costs of reentering such a well are large relative to the potential profits to be derived from such a decision. Eliminating the severance tax does not provide the incentive needed to reenter and produce an abandoned well. An empirical examination of the Kansas severance tax imposed in 1983 compares the present value of an abandoned well with the costs of reentering such a well. This comparison leads to the conclusion that, generally, a well that was

  14. A statistical model for multidimensional irreversible electroporation cell death in tissue

    Directory of Open Access Journals (Sweden)

    Rubinsky Boris

    2010-02-01

    Full Text Available Abstract Background Irreversible electroporation (IRE is a minimally invasive tissue ablation technique which utilizes electric pulses delivered by electrodes to a targeted area of tissue to produce high amplitude electric fields, thus inducing irreversible damage to the cell membrane lipid bilayer. An important application of this technique is for cancer tissue ablation. Mathematical modelling is considered important in IRE treatment planning. In the past, IRE mathematical modelling used a deterministic single value for the amplitude of the electric field required for causing cell death. However, tissue, particularly cancerous tissue, is comprised of a population of different cells of different sizes and orientations, which in conventional IRE are exposed to complex electric fields; therefore, using a deterministic single value is overly simplistic. Methods We introduce and describe a new methodology for evaluating IRE induced cell death in tissue. Our approach employs a statistical Peleg-Fermi model to correlate probability of cell death in heterogeneous tissue to the parameters of electroporation pulses such as the number of pulses, electric field amplitude and pulse length. For treatment planning, the Peleg-Fermi model is combined with a numerical solution of the multidimensional electric field equation cast in a dimensionless form. This is the first time in which this concept is used for evaluating IRE cell death in multidimensional situations. Results We illustrate the methodology using data reported in literature for prostate cancer cell death by IRE. We show how to fit this data to a Fermi function in order to calculate the critical statistic parameters. To illustrate the use of the methodology, we simulated 2-D irreversible electroporation protocols and produced 2-D maps of the statistical distribution of cell death in the treated region. These plots were compared to plots produced using a deterministic model of cell death by IRE and

  15. MRI study on reversible and irreversible electroporation induced blood brain barrier disruption.

    Directory of Open Access Journals (Sweden)

    Mohammad Hjouj

    Full Text Available Electroporation, is known to induce cell membrane permeabilization in the reversible (RE mode and cell death in the irreversible (IRE mode. Using an experimental system designed to produce a continuum of IRE followed by RE around a single electrode we used MRI to study the effects of electroporation on the brain. Fifty-four rats were injected with Gd-DOTA and treated with a G25 electrode implanted 5.5 mm deep into the striata. MRI was acquired immediately after treatment, 10 min, 20 min, 30 min, and up to three weeks following the treatment using: T1W, T2W, Gradient echo (GE, serial SPGR (DCE-MRI with flip angles ranging over 5-25°, and diffusion-weighted MRI (DWMRI. Blood brain barrier (BBB disruption was depicted as clear enhancement on T1W images. The average signal intensity in the regions of T1-enhancement, representing BBB disruption, increased from 1887±83 (arbitrary units immediately post treatment to 2246±94 20 min post treatment, then reached a plateau towards the 30 min scan where it reached 2289±87. DWMRI at 30 min showed no significant effects. Early treatment effects and late irreversible damage were clearly depicted on T2W. The enhancing volume on T2W has increased by an average of 2.27±0.27 in the first 24-48 hours post treatment, suggesting an inflammatory tissue response. The permanent tissue damage, depicted as an enhancing region on T2W, 3 weeks post treatment, decreased to an average of 50±10% of the T2W enhancing volumes on the day of the treatment which was 33±5% of the BBB disruption volume. Permanent tissue damage was significantly smaller than the volume of BBB disruption, suggesting, that BBB disruption is associated with RE while tissue damage with IRE. These results demonstrate the feasibility of applying reversible and irreversible electroporation for transient BBB disruption or permanent damage, respectively, and applying MRI for planning/monitoring disruption volume/shape by optimizing electrode positions

  16. DESAJUSTE EDUCATIVO POR REGIONES EN COLOMBIA: ¿COMPETENCIA POR SALARIOS O POR PUESTOS DE TRABAJO?

    Directory of Open Access Journals (Sweden)

    Maribel Castillo Caicedo

    2007-06-01

    Full Text Available Este trabajo aporta una perspectiva del fenómeno de la sobreeducación, entendida como un desajuste por exceso, entre el nivel educativo alcanzado por el individuo y el exigido por el puesto de trabajo en el cual se desempeña; esto se debe a que existe una demanda laboral estrecha de puestos de trabajo para personas calificadas en Colombia. Se analizan las contribuciones empíricas existentes y el debate sobre las mismas; se examinan las teorías que permiten explicar la existencia de un desajuste educativo y se realiza una revisión de la literatura internacional y nacional sobre el tema. Adicionalmente, se plantean una serie de hipótesis para desarrollar un esquema que permita determinar el comportamiento del individuo en el fenómeno de la sobreeducación.

  17. Influence of Irreversible Adsorption on the Glass Transition Temperature of Polymer Thin Films as Measured by Fluorescence

    Science.gov (United States)

    Burroughs, Mary; Priestley, Rodney

    2014-03-01

    Polymers confined to the nanometer length scale have been shown to exhibit deviations in the glass transition temperature (Tg) from the bulk. With the increasing use of confined polymers in nanotechnology, understanding and predicting this behavior is extremely relevant to industries ranging from pharmaceuticals to organic electronics. Recent work (Napolitano, Wübbenhorst, Nature Communications, 2, 260 (2011)) has connected deviations in Tg under confinement with irreversible physical adsorption of polymer chains at substrate interfaces. Here we investigate the influence of irreversibly adsorbed layers on the Tg of polystyrene (PS) thin films supported on silica via fluorescence. We examine the Tg of the brushes as a function of annealing time and irreversibly adsorbed layer thickness. By incorporating fluorescently labeled polymer layers into multilayered films of unlabeled polymer, we will examine the influence of brushes on adjacent layers dynamics. Finally, we will compare the results on PS with those of poly(methyl methacrylate).

  18. A continuum model of deformation, transport and irreversible changes in atomic structure in amorphous lithium–silicon electrodes

    International Nuclear Information System (INIS)

    Recent experiments and atomic scale computations indicate that the standard continuum models of diffusion in stressed solids do not accurately describe transport, deformation and stress in Li–Si alloys. We suggest that this is because classical models do not account for the irreversible changes in atomic structure of Si that are known to occur during a charge–discharge cycle. A more general model of diffusion in an amorphous solid is described, which permits unoccupied Si lattice sites to be created or destroyed. This may occur as a thermally activated process; or as a result of irreversible plastic deformation under stress. The model predicts a range of phenomena observed in experiment that cannot be captured using classical models, including irreversible changes in volume resulting from a charge–discharge cycle, asymmetry between the tensile and compressive yield stress, and a slow evolution in mechanical and electrochemical response over many charge–discharge cycles

  19. Irreversible volume growth in polymer-bonded powder systems: effects of crystalline anisotropy, particle size distribution, and binder strength

    Energy Technology Data Exchange (ETDEWEB)

    Maiti, A; Gee, R H; Hoffman, D; Fried, L E

    2007-08-22

    Pressed-powdered crystallites of intrinsically anisotropic materials have been shown to undergo irreversible volume expansion when subjected to repeated cycles of heating and cooling. We develop a coarse-grained (micron-scale) interaction Hamiltonian for this system and perform molecular dynamics simulations, which quantitatively reproduce the experimentally observed irreversible growth. The functional form and values of the interaction parameters at the coarse-grained level are motivated by our knowledge at the atomic/molecular scale, and allows a simple way to incorporate the effect of polymeric binder. We demonstrate that irreversible growth happens only in the presence of intrinsic crystalline anisotropy of the powder material, is mediated by particles much smaller than the average crystallite size, and can be significantly reduced in the presence of high-strength polymeric binder with elevated glass transition temperatures.

  20. Did nonlinear irreversible thermodynamics revolutionize the classical time conception of physics?

    Science.gov (United States)

    von Borzeszkowski, Horst-Heino; Wahsner, Renate

    1984-07-01

    From both physical and epistemological viewpoints, the following theses, which nowadays are often discussed in the literature, are examined: Nonlinear thermodynamics renders it possible to grasp evolutionary physical processes; for thermodynamics it introduces, instead of idealized reversible time, a directed time into physics; thus a science is established that is nearer to reality than classical physics. To analyze these theses, the relation of thermodynamics to dynamical physics is considered. In particular, it is demonstrated that, in classical as well as in modern thermodynamics, irreversibility is introduced via conditions which must be formulated in addition to the dynamical laws. To show the reason for this, the epistemological status of the physical time conception is analyzed, and its character as a physical measurement quantity is established.

  1. Strain induced irreversible critical current degradation in highly dense Bi-2212 round wire

    CERN Document Server

    Bjoerstad, R; Rikel, M.O.; Ballarino, A; Bottura, L; Jiang, J; Matras, M; Sugano, M; Hudspeth, J; Di Michiel, M

    2015-01-01

    The strain induced critical current degradation of overpressure processed straight Bi 2212/Ag wires has been studied at 77 K in self-field. For the first time superconducting properties, lattice distortions, composite wire stress and strain have been measured simultaneously in a high energy synchrotron beamline. A permanent Ic degradation of 5% occurs when the wire strain exceeds 0.60%. At a wire strain of about 0.65% a drastic n value and Ic reduction occur, and the composite stress and the Bi-2212 lattice parameter reach a plateau, indicating Bi-2212 filament fracturing. The XRD measurements show that Bi-2212 exhibits linear elastic behaviour up to the irreversible strain limit.

  2. A non-linear irreversible thermodynamic perspective on organic pigment proliferation and biological evolution

    CERN Document Server

    Michaelian, Karo

    2013-01-01

    The most important thermodynamic work performed by life today is the dissipation of the solar photon flux into heat through organic pigments in water. From this thermodynamic perspective, biological evolution is thus just the dispersal of organic pigments and water throughout Earth's surface, while adjusting the gases of Earth's atmosphere to allow the most intense part of the solar spectrum to penetrate the atmosphere and reach the surface to be intercepted by these pigments. The covalent bonding of atoms in organic pigments provides excited levels compatible with the energies of these photons. Internal conversion through vibrational relaxation to the ground state of these excited molecules when in water leads to rapid dissipation of the solar photons into heat, and this is the major source of entropy production on Earth. A non-linear irreversible thermodynamic analysis shows that the proliferation of organic pigments on Earth is a direct consequence of the pigments catalytic properties in dissipating the so...

  3. Irreversibility in a unitary finite-rate protocol: the concept of internal friction

    Science.gov (United States)

    Çakmak, Selçuk; Altintas, Ferdi; Müstecaplıoğlu, Özgür E.

    2016-07-01

    The concept of internal friction, a fully quantum mechanical phenomena, is investigated in a simple, experimentally accessible quantum system in which a spin-1/2 is driven by a transverse magnetic field in a quantum adiabatic process. The irreversible production of the waste energy due to the quantum friction is quantitatively analyzed in a forward-backward unitary transform of the system Hamiltonian by using the quantum relative entropy between the actual density matrix obtained in a parametric transformation and the one in a reversible adiabatic process. Analyzing the role of total transformation time and the different pulse control schemes on the internal friction reveal the non-monotone character of the internal friction as a function of the total protocol time and the possibility for almost frictionless solutions in finite-time transformations.

  4. Reversible and irreversible thermochromic phase transitions in single crystals of polydiacetylenes substituted with alkyl-urethanes

    Science.gov (United States)

    Koshihara, Shin-ya; Tokura, Yoshinori; Takeda, Kenji; Koda, Takao; Kobayashi, Akiko

    1990-06-01

    Reversible transitions between the two spectroscopically distinct phases (A and B phases) have been investigated for a new family of polydiacetylenes (PDAs) substituted with side groups of alkyl-urethane [-(CH2)4OCONH(CH2)n-1CH3:n =1-10]. Measurements of optical spectra as well as x-ray and calorimetric studies have revealed the first-order-like phase transitions in a series of PDAs with n=1-10 which are associated with an n-dependent thermal hysteresis ranging from 0 to 60 K in width. It has been found that the thermochromic changes become irreversible in all these PDAs once the hydrogen bond chains in the side groups are interrupted by heating beyond the polymer melting temperature.

  5. Irreversible thermochromic behavior in gold and silver nanorod/polymeric ionic liquid nanocomposite films.

    Science.gov (United States)

    Tollan, Christopher M; Marcilla, Rebeca; Pomposo, Jose A; Rodriguez, Javier; Aizpurua, Javier; Molina, Jon; Mecerreyes, David

    2009-02-01

    The novel application of gold and silver nanorods as irreversible thermochromic dyes in polymeric ionic liquid (PIL) nanocomposites is proposed here. These materials have been synthesized by anion exchange of an imidazolium-based PIL in a solution that also contained gold nanorods. This resulted in the entrapment of the nanoobjects within a solid polymer precipitate. In this article, the effect of the temperature was studied in relation to the change of shape and, consequently, color of the gold or silver nanorods within the films. For the nanocomposites studied here, a maximum of two visual thermochromic transitions was observed for gold nanorods and up to three transitions were observed for silver nanorods. PMID:20353222

  6. Estimation of Separation of Electrolytes and Organic Compounds by Nanofiltration Membranes Using an Irreversible Thermodynamic Model

    Institute of Scientific and Technical Information of China (English)

    PallabGhosh

    2003-01-01

    Nanofiltration separation has become a popular technique for removing large organic molecules and inorganic substances from water. It is achieved by a combination of three mechanisms: electrostatic repulsion,sieving and diffusion. In the present work, a model based on irreversible thermodynamics is extended and used to estimate rejection of inorganic salts and organic substances. Binary systems are modeled, where the feed contains an ion that is much less permeable to the membrane as compared with the other ion. The two model parameters are estimated by fitting the model to the experimental data. Variation of these parameters with the composition of the feed is described by an empirical correlation. This work attempts to describe transport through the nanofiltration membranes bv a simple model.

  7. Universality class of the reversible-irreversible transition in sheared suspensions.

    Science.gov (United States)

    Menon, Gautam I; Ramaswamy, Sriram

    2009-06-01

    Collections of non-Brownian particles suspended in a viscous fluid and subjected to oscillatory shear at very low Reynolds number have recently been shown to exhibit a remarkable dynamical phase transition separating reversible from irreversible behavior as the strain amplitude or volume fraction are increased. We present a simple model for this phenomenon, based on which we argue that this transition lies in the universality class of the conserved directed percolation models. This leads to predictions for the scaling behavior of a large number of experimental observables. Non-Brownian suspensions under oscillatory shear may thus constitute the first experimental realization of an inactive-active phase transition which is not in the universality class of conventional directed percolation. PMID:19658474

  8. Criticality and correlated dynamics at the irreversibility transition in periodically driven colloidal suspensions

    Science.gov (United States)

    Tjhung, Elsen; Berthier, Ludovic

    2016-03-01

    One possible framework to interpret the irreversibility transition observed in periodically driven colloidal suspensions is that of a non-equilibrium phase transition towards an absorbing reversible state at low amplitude of the driving force. We consider a simple numerical model for driven suspensions which allows us to characterize in great detail a large body of physical observables that can be experimentally determined to assess the existence and universality class of such a non-equilibrium phase transition. Characterizing the behaviour of static and dynamic correlation functions both in real and Fourier space we determine in particular several critical exponents for our model, which take values that are in good agreement with the universality class of directed percolation. We also provide a detailed analysis of single-particle and collective dynamics of the system near the phase transition, which appear intermittent and spatially correlated over diverging timescales and lengthscales, and provide clear signatures of the underlying criticality.

  9. Irreversible Electroporation of Hepatic and Pancreatic Malignancies: Radiologic-Pathologic Correlation.

    Science.gov (United States)

    Gonzalez-Beicos, Aldo; Venkat, Shree; Songrug, Tanakorn; Poveda, Julio; Garcia-Buitrago, Monica; Poozhikunnath Mohan, Prasoon; Narayanan, Govindarajan

    2015-09-01

    Irreversible electroporation (IRE) is a novel therapy that has shown to be a feasible and promising alternative to conventional ablative techniques when treating tumors near vital structures or blood vessels. The clinical efficacy of IRE has been evaluated using established imaging criteria. This study evaluates the histologic and imaging response of hepatic and pancreatic malignancies that were surgically resected after IRE. In total, 12 lesions ablated with IRE were included, including 3 pancreatic carcinomas, 5 primary tumors of the liver, and 4 metastatic tumors of the liver. The rate of complete response to IRE was 25% based on the histologic evaluation of the resected tumors. Although treatment-related vessel wall changes were noted in several cases in histologic findings, there was no evidence of vascular luminal narrowing or obliteration in any of the specimens. The imaging response to IRE before surgical resection usually resulted in underestimation of disease burden when compared with the histologic response seen on the resected specimens. PMID:26365548

  10. Percutaneous irreversible electroporation of locally advanced pancreatic carcinoma using the dorsal approach: a case report.

    Science.gov (United States)

    Scheffer, Hester J; Melenhorst, Marleen C A M; Vogel, Jantien A; van Tilborg, Aukje A J M; Nielsen, Karin; Kazemier, Geert; Meijerink, Martijn R

    2015-06-01

    Irreversible electroporation (IRE) is a novel image-guided ablation technique that is increasingly used to treat locally advanced pancreatic carcinoma (LAPC). We describe a 67-year-old male patient with a 5 cm stage III pancreatic tumor who was referred for IRE. Because the ventral approach for electrode placement was considered dangerous due to vicinity of the tumor to collateral vessels and duodenum, the dorsal approach was chosen. Under CT-guidance, six electrodes were advanced in the tumor, approaching paravertebrally alongside the aorta and inferior vena cava. Ablation was performed without complications. This case describes that when ventral electrode placement for pancreatic IRE is impaired, the dorsal approach could be considered alternatively. PMID:25288173

  11. Percutaneous Irreversible Electroporation of Locally Advanced Pancreatic Carcinoma Using the Dorsal Approach: A Case Report

    International Nuclear Information System (INIS)

    Irreversible electroporation (IRE) is a novel image-guided ablation technique that is increasingly used to treat locally advanced pancreatic carcinoma (LAPC). We describe a 67-year-old male patient with a 5 cm stage III pancreatic tumor who was referred for IRE. Because the ventral approach for electrode placement was considered dangerous due to vicinity of the tumor to collateral vessels and duodenum, the dorsal approach was chosen. Under CT-guidance, six electrodes were advanced in the tumor, approaching paravertebrally alongside the aorta and inferior vena cava. Ablation was performed without complications. This case describes that when ventral electrode placement for pancreatic IRE is impaired, the dorsal approach could be considered alternatively

  12. Effects of oxymorphazone in frogs: long lasting antinociception in vivo, and apparently irreversible binding in vitro

    International Nuclear Information System (INIS)

    Oxymorphazone was found to be a relatively weak antinociceptive drug in intact frog (Rana esculenta) when acetic acid was used as pain stimulus. Frogs remained analgesic for at least 48 hrs following oxymorphazone administration. The ligand increased the latency of wiping reflex in spinal frogs too. There effects were blocked by naloxone. In equilibrium binding studies (3H)oxymorphazone had high affinity to the opioid receptors of frog brain and spinal cord as well. Kinetic experiments show that only 25% of the bound (3H)oxymorphazone is readily dissociable. Preincubation of the membranes with labeled oxymorphazone results in a washing resistant inhibition of the opioid binding sites. At least 70% of the (3H)oxymorphazone specific binding is apparently irreversible after reaction at 5 nM ligand concentration, and this can be enhanced by a higher concentration of tritiated ligand

  13. Contribution of control theory to the problem of microscopic reversibility-macroscopic irreversibility

    CERN Document Server

    Gumowski, I

    1976-01-01

    The problem of microscopic reversibility-macroscopic irreversibility appears in control theory via the control of a dynamic system containing a subsystem which is not in a state analogous to thermodynamic equilibrium (example: bunch of charged particles in an accelerator). In such a case the appropriate macroscopic description has to be established simultaneously with the control configuration. The macroscopic state of the non-equilibrium subsystem is defined implicitly by a Hamiltonian description valid on the microscopic level (single particles acted upon by collective forces in the example of an accelerator). The excess fine structure of the microscopic state, i.e. the complexity irrelevant for the control problem must be properly smoothed. The problem of proper smoothing coincides with a classical problem of statistical mechanics: determination of the master equation from a given system of Hamiltonian equations. After a short review of some basic assumptions and definitions of control theory, four particu...

  14. Irreversible embrittlement of Alloy 600 in hydrogenated steam at 400 C

    International Nuclear Information System (INIS)

    Intergranular embrittlement of Alloy 600 has been studied by pre-exposing thin foils, 20--30 pm thick, in high-pressure steam/hydrogen at 400 C, then fracturing them at room temperature. Hydrogen egress was believed to be complete before fracture, so any embrittlement was due to irreversible damage at the grain boundaries. Embrittlement was observed in both as-received and cold-worked material, to a depth of a few microns. The kinetics of this embrittlement are insufficient to account for stress corrosion velocities measured in this environment, unless one postulates an improbably frequent crack advance. The most likely cause of embrittlement is selective intergranular oxidation of chromium. Various other internal embrittlement processes are discussed

  15. Percutaneous Irreversible Electroporation of Locally Advanced Pancreatic Carcinoma Using the Dorsal Approach: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Scheffer, Hester J., E-mail: hj.scheffer@vumc.nl; Melenhorst, Marleen C. A. M., E-mail: m.melenhorst@vumc.nl [VU University Medical Center, Department of Radiology and Nuclear Medicine (Netherlands); Vogel, Jantien A., E-mail: j.a.vogel@amc.uva.nl [Academic Medical Center, Department of Surgery (Netherlands); Tilborg, Aukje A. J. M. van, E-mail: a.vantilborg@vumc.nl [VU University Medical Center, Department of Radiology and Nuclear Medicine (Netherlands); Nielsen, Karin, E-mail: k.nielsen@vumc.nl; Kazemier, Geert, E-mail: g.kazemier@vumc.nl [VU University Medical Center, Department of Surgery (Netherlands); Meijerink, Martijn R., E-mail: mr.meijerink@vumc.nl [VU University Medical Center, Department of Radiology and Nuclear Medicine (Netherlands)

    2015-06-15

    Irreversible electroporation (IRE) is a novel image-guided ablation technique that is increasingly used to treat locally advanced pancreatic carcinoma (LAPC). We describe a 67-year-old male patient with a 5 cm stage III pancreatic tumor who was referred for IRE. Because the ventral approach for electrode placement was considered dangerous due to vicinity of the tumor to collateral vessels and duodenum, the dorsal approach was chosen. Under CT-guidance, six electrodes were advanced in the tumor, approaching paravertebrally alongside the aorta and inferior vena cava. Ablation was performed without complications. This case describes that when ventral electrode placement for pancreatic IRE is impaired, the dorsal approach could be considered alternatively.

  16. The irreversibility line of (Hg, Cr)Sr2CuO4+δ superconductor

    International Nuclear Information System (INIS)

    Superconducting (Hg, Cr)-1201 phase was synthesized with a nominal composition Hg0.7, Cr0.3Sr2CuO4+δ by solid state reaction method in vacuum-sealed quartz-tube. X-ray diffraction (XRD) analysis of the sample showed a tetragonal symmetry with lattice parameters a = 3.842 (2) A and c = 8.641 (5) A. Ac-susceptibility, dc-magnetization, and dc-resistivity measurements indicate a Tc of 60 K. The irreversibility line (IRL) was obtained from the merging point of the zero field cooled (ZFC) and field cooled (FC) magnetization measurements at several applied fields. The fit H =A(1 -T / Tc)n gave a value of 2.55 for the exponent n. (author)

  17. Metaphit irreversibly inhibits (/sup 3/H)threo-(+/-)-methylphenidate binding to rat striatal tissue

    Energy Technology Data Exchange (ETDEWEB)

    Schweri, M.M.; Jacobson, A.E.; Lessor, R.A.; Rice, K.C.

    1987-01-01

    Metaphit (1-(1-(3-isothiocyanatophenyl)cyclohexyl)-piperidine), a derivative of phencyclidine that contains an isothiocyanate group on the meta position of the aromatic ring, resembles its parent compound (phencyclidine) in its ability to inhibit the binding of the stimulant drug (/sup 3/H)threo-(+/-)-methylphenidate to crude synaptosomal membranes from rat striatal tissue (IC50 = 1.4 and 6.2 microM for phencyclidine and Metaphit, respectively). Unlike phencyclidine, however, Metaphit appears to inhibit binding of the radiolabeled stimulant in an irreversible manner, as the degree of inhibition of binding of the stimulant does not diminish when the Metaphit-treated tissue is subjected to repeated washings before determination of the binding of (/sup 3/H)threo-(+/-)-methylphenidate. This finding suggests that Metaphit may be a useful tool in the study of the molecular basis of stimulant action.

  18. Graphical Analysis of PET Data Applied to Reversible and Irreversible Tracers

    Energy Technology Data Exchange (ETDEWEB)

    Logan, Jean

    1999-11-18

    Graphical analysis refers to the transformation of multiple time measurements of plasma and tissue uptake data into a linear plot, the slope of which is related to the number of available tracer binding sites. This type of analysis allows easy comparisons among experiments. No particular model structure is assumed, however it is assumed that the tracer is given by bolus injection and that both tissue uptake and the plasma concentration of unchanged tracer are monitored following tracer injection. The requirement of plasma measurements can be eliminated in some cases when a reference region is available. There are two categories of graphical methods which apply to two general types of ligands--those which bind reversibly during the scanning procedure and those which are irreversible or trapped during the time of the scanning procedure.

  19. Mass and Heat Diffusion in Ternary Polymer Solutions: A Classical Irreversible Thermodynamics Approach

    CERN Document Server

    Es-haghi, S Shams

    2016-01-01

    Governing equations for evolution of concentration and temperature in three-component systems were derived in the framework of classical irreversible thermodynamics using Onsager variational principle and were presented for solvent/solvent/polymer and solvent/polymer/polymer systems. The derivation was developed from the Gibbs equation of equilibrium thermodynamics using the local equilibrium hypothesis, Onsager reciprocal relations and Prigogine theorem for systems in mechanical equilibrium. It was shown that the details of mass and heat diffusion phenomena in a ternary system are completely expressed by a 3x3 matrix whose entries are mass diffusion coefficients (4 entries), thermal diffusion coefficients (2 entries) and three entries that describe the evolution of heat in the system. The entries of the diffusion matrix are related to the elements of Onsager matrix that are bounded by some constraints to satisfy the positive definiteness of entropy production in the system. All the elements of diffusion matr...

  20. Analysis of the irreversible process of proton transport in the purple membrane of Halobacterium halobium.

    Science.gov (United States)

    Hong, T; Manqi, T

    1980-04-01

    The proton transport across biological membrane, accompanied by energy transformation, is closely related with many basic processes involved in the maintenance of life. Active researches are carried out in this field, but so far we have not known a complete calculation. This paper presents a model of an open and closed photon-controlled ion pore with a quantitative analysis of the irreversible process of the proton transport across the purple membrane. Upon absorbing photon by the purple membrane, the deprotonation of the Schiff base causes the ion pore to open, but it will close when it returns to bR570. A set of nonlinear differential equations describing this model is given. The stability of the equations is discussed. The results of the numerical calculation for steady state are found in good agreement with the experimental data of Bakker. PMID:6250213

  1. Environment-induced effects on quantum chaos decoherence, delocalization and irreversibility

    CERN Document Server

    Hu, B L; Hu, B L; Shiokawa, K

    1997-01-01

    Decoherence in quantum systems which are classically chaotic is studied. It is well-known that a classically chaotic system when quantized loses many prominent chaotic traits. We show that interaction of the quantum system with an environment can under general circumstances quickly diminish quantum coherence and reenact some characteristic classical chaotic behavior. We use the Feynman-Vernon influence functional formalism to study the effect of an ohmic environment at high temperature on two classically-chaotic systems: The linear Arnold cat map (QCM) and the nonlinear quantum kicked rotor (QKR). Features of quantum chaos such as recurrence in QCM and diffusion suppression leading to localization in QKR are destroyed in a short time due to environment-induced decoherence. Decoherence also undermines localization and induces an apparent transition from reversible to irreversible dynamics in quantum chaotic systems.

  2. Research on the dissipation field of a nonlinear continuum based on the operational irreversible thermodynamics

    International Nuclear Information System (INIS)

    The dissipation field of a nonlinear continuum is studied by a new operational theory of irreversible thermodynamics, the evolution equations of the dissipation field can be obtained under the condition of knowing the phenomenological nonlinear constitutive relation of the continuum. In this theory, the dissipation equation of the basic state, which is corresponding to the minimum dissipation principle, is utilized to solve the distribution of dissipation field regarding the equilibrium problem of quasi-statics, and the dissipation equations of higher order are directly related to the dynamics of dissipation fields. The paper also presents a method showing the dissipation force operator by using Helmholtz's free energy function. This paper will also show important phenomena of the localized deformation, such as the plastic instability of necking and shear band, which are predicted in the form of an analytical formula

  3. Exploring the optimal performances of irreversible single resonance energy selective electron refrigerators

    Science.gov (United States)

    Zhou, Junle; Chen, Lingen; Ding, Zemin; Sun, Fengrui

    2016-05-01

    Applying finite-time thermodynamics (FTT) and electronic transport theory, the optimal performances of irreversible single resonance energy selective electron (ESE) refrigerator are analyzed. The effects of heat leakage between two electron reservoirs on optimal performances are discussed. The influences of system operating parameters on cooling load, coefficient of performance (COP), figure of merit and ecological function are demonstrated using numerical examples. Comparative performance analyses among different objective functions show that performance characteristics at maximum ecological function and maximum figure of merit are of great practical significance. Combining the two optimization objectives of maximum ecological function and maximum figure of merit together, more specific optimal ranges of cooling load and COP are obtained. The results can provide some advices to the design of practical electronic machine systems.

  4. Nonlinear Gamow vectors, shock waves and irreversibility in optically nonlocal media

    CERN Document Server

    Gentilini, Silvia; Marcucci, Giulia; DelRe, Eugenio; Conti, Claudio

    2015-01-01

    Dispersive shock waves dominate wave-breaking phenomena in Hamiltonian systems. In the absence of loss, these highly irregular and disordered waves are potentially reversible. However, no experimental evidence has been given about the possibility of inverting the dynamics of a dispersive shock wave and turn it into a regular wave-front. Nevertheless, the opposite scenario, i.e., a smooth wave generating turbulent dynamics is well studied and observed in experiments. Here we introduce a new theoretical formulation for the dynamics in a highly nonlocal and defocusing medium described by the nonlinear Schroedinger equation. Our theory unveils a mechanism that enhances the degree of irreversibility. This mechanism explains why a dispersive shock cannot be reversed in evolution even for an arbitrarirly small amount of loss. Our theory is based on the concept of nonlinear Gamow vectors, i.e., power dependent generalizations of the counter-intuitive and hereto elusive exponentially decaying states in Hamiltonian sys...

  5. Chemical modeling of irreversible reactions in nuclear waste-water-rock systems

    International Nuclear Information System (INIS)

    Chemical models of aqueous geochemical systems are usually built on the concept of thermodynamic equilibrium. Though many elementary reactions in a geochemical system may be close to equilibrium, others may not be. Chemical models of aqueous fluids should take into account that many aqueous redox reactions are among the latter. The behavior of redox reactions may critically affect migration of certain radionuclides, especially the actinides. In addition, the progress of reaction in geochemical systems requires thermodynamic driving forces associated with elementary reactions not at equilibrium, which are termed irreversible reactions. Both static chemical models of fluids and dynamic models of reacting systems have been applied to a wide spectrum of problems in water-rock interactions. Potential applications in nuclear waste disposal range from problems in geochemical aspects of site evaluation to those of waste-water-rock interactions. However, much further work in the laboratory and the field will be required to develop and verify such applications of chemical modeling

  6. Local Ablative Strategies for Ductal Pancreatic Cancer (Radiofrequency Ablation, Irreversible Electroporation): A Review.

    Science.gov (United States)

    Paiella, Salvatore; Salvia, Roberto; Ramera, Marco; Girelli, Roberto; Frigerio, Isabella; Giardino, Alessandro; Allegrini, Valentina; Bassi, Claudio

    2016-01-01

    Pancreatic ductal adenocarcinoma (PDAC) has still a dismal prognosis. Locally advanced pancreatic cancer (LAPC) accounts for the 40% of the new diagnoses. Current treatment options are based on chemo- and radiotherapy regimens. Local ablative techniques seem to be the future therapeutic option for stage-III patients with PDAC. Radiofrequency Ablation (RFA) and Irreversible Electroporation (IRE) are actually the most emerging local ablative techniques used on LAPC. Initial clinical studies on the use of these techniques have already demonstrated encouraging results in terms of safety and feasibility. Unfortunately, few studies on their efficacy are currently available. Even though some reports on the overall survival are encouraging, randomized studies are still required to corroborate these findings. This study provides an up-to-date overview and a thematic summary of the current available evidence on the application of RFA and IRE on PDAC, together with a comparison of the two procedures. PMID:26981115

  7. The Effect of Blood Flow on Magnetic Resonance Imaging of Non Thermal Irreversible Electroporation

    Science.gov (United States)

    Hjouj, Mohammad; Lavee, Jacob; Last, David; Guez, David; Daniels, Dianne; Sharabi, Shirley; Rubinsky, Boris; Mardor, Yael

    2013-10-01

    To generate an understanding of the physiological significance of MR images of Non-Thermal Irreversible Electroporation (NTIRE) we compared the following MR imaging sequences: T1W, T2W, PD, GE, and T2 SPAIR acquired after NTIRE treatment in a rodent liver model. The parameters that were studied included the presence or absence of a Gd-based contrast agent, and in vivo and ex-vivo NTIRE treatments in the same liver. NTIRE is a new minimally invasive tissue ablation modality in which pulsed electric fields cause molecularly selective cell death while, the extracellular matrix and large blood vessels remain patent. This attribute of NTIRE is of major clinical importance as it allows treatment of undesirable tissues near critical blood vessels. The presented study results suggest that MR images acquired following NTIRE treatment are all directly related to the unique pattern of blood flow after NTIRE treatment and are not produced in the absence of blood flow.

  8. Local Ablative Strategies for Ductal Pancreatic Cancer (Radiofrequency Ablation, Irreversible Electroporation: A Review

    Directory of Open Access Journals (Sweden)

    Salvatore Paiella

    2016-01-01

    Full Text Available Pancreatic ductal adenocarcinoma (PDAC has still a dismal prognosis. Locally advanced pancreatic cancer (LAPC accounts for the 40% of the new diagnoses. Current treatment options are based on chemo- and radiotherapy regimens. Local ablative techniques seem to be the future therapeutic option for stage-III patients with PDAC. Radiofrequency Ablation (RFA and Irreversible Electroporation (IRE are actually the most emerging local ablative techniques used on LAPC. Initial clinical studies on the use of these techniques have already demonstrated encouraging results in terms of safety and feasibility. Unfortunately, few studies on their efficacy are currently available. Even though some reports on the overall survival are encouraging, randomized studies are still required to corroborate these findings. This study provides an up-to-date overview and a thematic summary of the current available evidence on the application of RFA and IRE on PDAC, together with a comparison of the two procedures.

  9. Effects of oxymorphazone in frogs: long lasting antinociception in vivo, and apparently irreversible binding in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Benyhe, S.; Hoffman, G.; Varga, E.; Hosztafi, S.; Toth, G.; Borsodi, A.; Wollemann, M.

    1989-01-01

    Oxymorphazone was found to be a relatively weak antinociceptive drug in intact frog (Rana esculenta) when acetic acid was used as pain stimulus. Frogs remained analgesic for at least 48 hrs following oxymorphazone administration. The ligand increased the latency of wiping reflex in spinal frogs too. There effects were blocked by naloxone. In equilibrium binding studies (/sup 3/H)oxymorphazone had high affinity to the opioid receptors of frog brain and spinal cord as well. Kinetic experiments show that only 25% of the bound (/sup 3/H)oxymorphazone is readily dissociable. Preincubation of the membranes with labeled oxymorphazone results in a washing resistant inhibition of the opioid binding sites. At least 70% of the (/sup 3/H)oxymorphazone specific binding is apparently irreversible after reaction at 5 nM ligand concentration, and this can be enhanced by a higher concentration of tritiated ligand.

  10. A novel alkylating agent Melflufen induces irreversible DNA damage and cytotoxicity in multiple myeloma cells.

    Science.gov (United States)

    Ray, Arghya; Ravillah, Durgadevi; Das, Deepika S; Song, Yan; Nordström, Eva; Gullbo, Joachim; Richardson, Paul G; Chauhan, Dharminder; Anderson, Kenneth C

    2016-08-01

    Our prior study utilized both in vitro and in vivo multiple myeloma (MM) xenograft models to show that a novel alkylator melphalan-flufenamide (Melflufen) is a more potent anti-MM agent than melphalan and overcomes conventional drug resistance. Here we examined whether this potent anti-MM activity of melflufen versus melphalan is due to their differential effect on DNA damage and repair signalling pathways via γ-H2AX/ATR/CHK1/Ku80. Melflufen-induced apoptosis was associated with dose- and time-dependent rapid phosphorylation of γ-H2AX. Melflufen induces γ-H2AX, ATR, and CHK1 as early as after 2 h exposure in both melphalan-sensitive and -resistant cells. However, melphalan induces γ-H2AX in melphalan-sensitive cells at 6 h and 24 h; no γ-H2AX induction was observed in melphalan-resistant cells even after 24 h exposure. Similar kinetics was observed for ATR and CHK1 in meflufen- versus melphalan-treated cells. DNA repair is linked to melphalan-resistance; and importantly, we found that melphalan, but not melflufen, upregulates Ku80 that repairs DNA double-strand breaks. Washout experiments showed that a brief (2 h) exposure of MM cells to melflufen is sufficient to initiate an irreversible DNA damage and cytotoxicity. Our data therefore suggest that melflufen triggers a rapid, robust, and an irreversible DNA damage which may account for its ability to overcome melphalan-resistance in MM cells. PMID:27098276

  11. A facile route for irreversible bonding of plastic-PDMS hybrid microdevices at room temperature.

    Science.gov (United States)

    Tang, Linzhi; Lee, Nae Yoon

    2010-05-21

    Plastic materials do not generally form irreversible bonds with poly(dimethylsiloxane) (PDMS) regardless of oxygen plasma treatment and a subsequent thermal process. In this paper, we perform plastic-PDMS bonding at room temperature, mediated by the formation of a chemically robust amine-epoxy bond at the interfaces. Various plastic materials, such as poly(methylmethacrylate) (PMMA), polycarbonate (PC), polyimide (PI), and poly(ethylene terephthalate) (PET) were adopted as choices for plastic materials. Irrespective of the plastic materials used, the surfaces were successfully modified with amine and epoxy functionalities, confirmed by the surface characterizations such as water contact angle measurements and X-ray photoelectron spectroscopy (XPS), and chemically robust and irreversible bonding was successfully achieved within 1 h at room temperature. The bonding strengths of PDMS with PMMA and PC sheets were measured to be 180 and 178 kPa, respectively, and their assemblies containing microchannel structures endured up to 74 and 84 psi (510 and 579 kPa) of introduced compressed air, respectively, without destroying the microdevices, representing a robust and highly stable interfacial bonding. In addition to microchannel-molded PDMS bonded with flat plastic substrates, microchannel-embossed plastics were also bonded with a flat PDMS sheet, and both types of bonded assemblies displayed sufficiently robust bonding, tolerating an intense influx of liquid whose per-minute injection volume was nearly 1000 to 2000 times higher than the total internal volume of the microchannel used. In addition to observing the bonding performance, we also investigated the potential of surface amine and epoxy functionalities as durable chemical adhesives by observing their storage-time-dependent bonding performances. PMID:20445880

  12. Irreversible effects of calcium ions on the plasma membrane calcium pump.

    Science.gov (United States)

    Ward, D G; Walton, T J; Cavieres, J D

    1993-12-01

    The calcium pump of human red cells can be irreversibly activated by preincubation of the membranes in the presence of calcium ions, with a pattern reminiscent of that produced by controlled trypsin attack. With 1 mM Ca2+, the activity of the basal enzyme increases three to fourfold over 30 to 60 min, to levels about half those obtained in the presence of calmodulin. On the whole, the effect occurs slowly, with a very low Ca2+ affinity at 37 degrees C and is unaffected by serine-protease inhibitors. The activation caused by 1 mM Ca2+ is little affected by leupeptin (a thiol-protease inhibitor) and that obtained at 10 microM Ca2+ is not inhibited. Preincubations at 0 degrees C also lead to activation, to a level up to half that seen at 37 degrees C, and the effect is not affected by leupeptin or antipain. No activation is observed by preincubating soluble purified Ca,Mg-ATPase in Ca(2+)-containing solutions at 37 degrees C. Instead, calcium ions protect the detergent-solubilized enzyme from thermal inactivation, the effect being half-maximal between 10 and 20 microM Ca2+. We conclude that the activation of the membrane-bound Ca,Mg-ATPase by Ca2+ should result from an irreversible conformational change in the enzyme and not from attack by a membrane-bound protease, and that this change presumably arises from the release of inhibitory particles existing in the original membrane preparations. PMID:8114081

  13. Thermomagnetic behaviour and compositional irreversibility on (Fe/Si){sub 3} multilayer films

    Energy Technology Data Exchange (ETDEWEB)

    Badía-Romano, L., E-mail: lbadia@unizar.es [Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, E-50009 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Rubín, J. [Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, E-50009 Zaragoza (Spain); Departamento de Ciencia de Materiales e Ingeniería Metalúrgica, Universidad de Zaragoza, E-50018 Zaragoza (Spain); Magén, C. [Departamento de Física de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Laboratorio de Microscopías Avanzadas (LMA), Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, E-50018 Zaragoza (Spain); Fundación ARAID, E-50004 Zaragoza (Spain); Bartolomé, F. [Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, E-50009 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Sesé, J.; Ibarra, M.R. [Departamento de Física de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza (Spain); Laboratorio de Microscopías Avanzadas (LMA), Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, E-50018 Zaragoza (Spain); Bartolomé, J. [Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, E-50009 Zaragoza (Spain); Departamento de Física de la Materia Condensada, Universidad de Zaragoza, E-50009 Zaragoza (Spain); and others

    2014-09-01

    This work presents the correlation between the morphology and magnetic properties of (Fe/Si){sub 3} multilayers with different Fe layer thicknesses and fixed Si spacer thickness in a broad temperature range (5irreversible thermal process as temperature increases from 300 to 450 K that is correlated to the formation of a ferromagnetic silicide phase. At higher temperature this phase transforms into a paramagnetic Fe–Si phase. - Highlights: • A thermomagnetic study on (Fe/Si){sub 3} multilayers is performed by in situ annealing. • We assess on the Fe layer thickness dependence, while the Si spacer is fixed. • 90° and AF interlayer exchange couplings are found depending on the Fe thickness. • We report an irreversible thermal process, correlated to chemical transformations. • The integrity of these (Fe/Si){sub 3} films is conserved just till T≈410K.

  14. Towards the creation of decellularized organ constructs using irreversible electroporation and active mechanical perfusion

    Directory of Open Access Journals (Sweden)

    Robertson John

    2010-12-01

    Full Text Available Abstract Background Despite advances in transplant surgery and general medicine, the number of patients awaiting transplant organs continues to grow, while the supply of organs does not. This work outlines a method of organ decellularization using non-thermal irreversible electroporation (N-TIRE which, in combination with reseeding, may help supplement the supply of organs for transplant. Methods In our study, brief but intense electric pulses were applied to porcine livers while under active low temperature cardio-emulation perfusion. Histological analysis and lesion measurements were used to determine the effects of the pulses in decellularizing the livers as a first step towards the development of extracellular scaffolds that may be used with stem cell reseeding. A dynamic conductivity numerical model was developed to simulate the treatment parameters used and determine an irreversible electroporation threshold. Results Ninety-nine individual 1000 V/cm 100-μs square pulses with repetition rates between 0.25 and 4 Hz were found to produce a lesion within 24 hours post-treatment. The livers maintained intact bile ducts and vascular structures while demonstrating hepatocytic cord disruption and cell delamination from cord basal laminae after 24 hours of perfusion. A numerical model found an electric field threshold of 423 V/cm under specific experimental conditions, which may be used in the future to plan treatments for the decellularization of entire organs. Analysis of the pulse repetition rate shows that the largest treated area and the lowest interstitial density score was achieved for a pulse frequency of 1 Hz. After 24 hours of perfusion, a maximum density score reduction of 58.5 percent had been achieved. Conclusions This method is the first effort towards creating decellularized tissue scaffolds that could be used for organ transplantation using N-TIRE. In addition, it provides a versatile platform to study the effects of pulse

  15. (phoenicopterus roseus por intoxicación aguda por plomo

    Directory of Open Access Journals (Sweden)

    D Romero

    2007-01-01

    Full Text Available La presencia de plomo en el medio ambiente es un hecho indiscutible. Ello es objeto de gran interés sanitario pues repercute tanto en la salud de los animales como en la del ser humano. El plumbismo es una intoxicación que puede afectar a cualquier especie animal. En el ámbito de la fauna silvestre se asocia principalmente a la actividad cinegética en los humedales y a la ingestión de plomo metálico por parte de las aves que frecuentan estos ecosistemas. En España cada año mueren decenas de miles de aves acuáticas como consecuencia de la ingesta de perdigones de plomo. En los individuos capturados enfermos se pueden observar signos clínicos, mientras que a partir de muestras de cadáveres se obtienen datos sobre niveles tisulares de plomo. Sin embargo la evaluación de lesiones anatomopatológicas en animales de vida silvestre es difícil de realizar por la dificultad de encontrar animales recién muertos o afectados de un cuadro agudo mortal. La reproducción de esta patología en animales de experimentación se suele realizar en cisnes, palomas o patos, pero no en flamencos, por lo que no es usual disponer de datos histológicos en esta especie. En este trabajo presentamos la clínica, analítica y estudio microscópico de diferentes tejidos de un flamenco común (Phoenicopterus roseus muerto por plumbismo.

  16. Impact of pseudo-gap states on the pinning energy and irreversibility field of high temperature superconductors

    Directory of Open Access Journals (Sweden)

    Guy Deutscher

    2014-09-01

    Full Text Available The existence of pseudo-gap states at energies larger than the coherence energy scale is shown to be at the origin of the difficulties encountered in achieving strong vortex pinning in the high Tc cuprates. Reduction or elimination of the pseudo-gap states by overdoping is effective in increasing the condensation energy and the irreversibility field. In YBa2Cu3O7, a full BCS state, with a single energy scale, can be restored, leading to the highest known irreversibility field and pinning strength. In the bismuthates, the detrimental effect of the pseudo-gap states can only be mitigated to some extent by overdoping.

  17. First order phase transition at the irreversibility line of Bi2Sr2CaCu2O8

    Science.gov (United States)

    Pastoriza, H.; Goffman, M. F.; Arribére, A.; de La Cruz, F.

    1994-05-01

    Magnetization and susceptibility measurements show a first order phase transition in the magnetic flux structure at the irreversibility line of Bi2Sr2CaCu2O8+δ single crystals, in the field range 0irreversibility line has the known frequency dependence.

  18. Interaction effect detected by compared of the irreversible and remanent initial magnetization curves in Ni-Cu-Zn ferrites

    OpenAIRE

    Goev, G.; Masheva, V.

    2013-01-01

    A new technique for estimation of magnetic interaction effects of initial magnetization curves has been proposed. It deals with remanence, and initial irreversible magnetization, curves. The method is applied for single-phase polycrystalline Ni0.85-xCu0.15ZnxFe2O4, (x = 0, 0.2, 0.4 and 0.6), which were synthesized by a standard ceramic technology. A study of the initial reversible and irreversible magnetization processes in ferrite materials was carried out. The field dependence of the irreve...

  19. Use of cadmium in solution in the EL 4 reactor moderator irreversible fixing of cadmium on the metallic surfaces

    International Nuclear Information System (INIS)

    In the framework of research into the poisoning of the EL-4 reactor by cadmium sulphate, measurements have been made by two different methods of the residual amounts of cadmium liable to be fixed irreversibly on the surfaces in contact with the heavy water. A marked influence of the pH has been noticed. The mechanism of the irreversible fixing is compatible with the hypothesis of an ion-exchange in the surface oxide layer. In a sufficiently wide range of pH the cadmium thus fixed causes very little residual poisoning. The stability of the cadmium sulphate solutions is however rather low in the conditions of poisoning. (authors)

  20. Application of exergetic sustainable index to the quantum irreversible Diesel refrigerator cycles for 1D box system

    Science.gov (United States)

    Açıkkalp, Emin; Caner, Necmettin

    2015-04-01

    In this paper, an irreversible quantum Diesel refrigerator for a 1D-box system is described and analyzed. The exergetic sustainability index that is the rate of the exergy output from the system to the total exergetic losses including exergy destruction and exergy loss from the system is applied for the first time to an irreversible quantum engine. Other thermodynamic parameters including work input, cooling load, exergy destruction, COP and exergy efficiency are investigated according to the cycle temperatures and numerical results are presented.