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Sample records for leprosum enl reactions

  1. A leprosy clinical severity scale for erythema nodosum leprosum: An international, multicentre validation study of the ENLIST ENL Severity Scale.

    Science.gov (United States)

    Walker, Stephen L; Sales, Anna M; Butlin, C Ruth; Shah, Mahesh; Maghanoy, Armi; Lambert, Saba M; Darlong, Joydeepa; Rozario, Benjamin Jewel; Pai, Vivek V; Balagon, Marivic; Doni, Shimelis N; Hagge, Deanna A; Nery, José A C; Neupane, Kapil D; Baral, Suwash; Sangma, Biliom A; Alembo, Digafe T; Yetaye, Abeba M; Hassan, Belaynesh A; Shelemo, Mohammed B; Nicholls, Peter G; Lockwood, Diana N J

    2017-07-01

    We wished to validate our recently devised 16-item ENLIST ENL Severity Scale, a clinical tool for measuring the severity of the serious leprosy associated complication of erythema nodosum leprosum (ENL). We also wished to assess the responsiveness of the ENLIST ENL Severity Scale in detecting clinical change in patients with ENL. Participants, recruited from seven centres in six leprosy endemic countries, were assessed using the ENLIST ENL Severity Scale by two researchers, one of whom categorised the severity of ENL. At a subsequent visit a further assessment using the scale was made and both participant and physician rated the change in ENL using the subjective categories of "Much better", "somewhat better", "somewhat worse" and "much worse" compared with "No change" or "about the same". 447 participants were assessed with the ENLIST ENL Severity Scale. The Cronbach alpha of the scale and each item was calculated to determine the internal consistency of the scale. The ENLIST ENL Severity Scale had good internal consistency and this improved following removal of six items to give a Cronbach's alpha of 0.77. The cut off between mild ENL and more severe disease was 9 determined using ROC curves. The minimal important difference of the scale was determined to be 5 using both participant and physician ratings of change. The 10-item ENLIST ENL Severity Scale is the first valid, reliable and responsive measure of ENL severity and improves our ability to assess and compare patients and their treatments in this severe and difficult to manage complication of leprosy. The ENLIST ENL Severity Scale will assist physicians in the monitoring and treatment of patients with ENL. The ENLIST ENL Severity Scale is easy to apply and will be useful as an outcome measure in treatment studies and enable the standardisation of other clinical and laboratory ENL research.

  2. Immunological status of ENL (Erythema Nodosum Leprosum patients: its relationship to bacterial load and levels of circulanting IL-2R Perfil imunológico de pacientes com ENL (Erythema Nodosum Leprosum: relação entre carga bacilar e os níveis de IL-2R circulantes

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    Leila M.M. Vieira

    1996-04-01

    Full Text Available Recent data suggest that the clinical course of reactional states in leprosy is closely related to the cytokine profile released locally or systemically by the patients. In the present study, patients with erythema nodosum leprosum (ENL were grouped according to the intensity of their clinical symptoms. Clinical and immunological aspects of ENL and the impact of these parameters on bacterial load were assessed in conjunction with patients' in vitro immune response to mycobacterial antigens. In 10 out of the 17 patients tested, BI (bacterial index was reduced by at least 1 log from leprosy diagnosis to the onset of their first reactional episode (ENL, as compared to an expected 0.3 log reduction in the unreactional group for the same MDT (multidrug therapy period. However, no difference in the rate of BI reduction was noted at the end of MDT among ENL and unreactional lepromatous patients. Accordingly, although TNF-alpha (tumor necrosis factor levels were enhanced in the sera of 70.6% of the ENL patients tested, no relationship was noted between circulating TNF-alpha levels and the decrease in BI detected at the onset of the reactional episode. Evaluation of bacterial viability of M. leprae isolated from the reactional lesions showed no growth in the mouse footpads. Only 20% of the patients demonstrated specific immune response to M. leprae during ENL. Moreover, high levels of soluble IL-2R (interleukin-2 receptor were present in 78% of the patients. Circulating anti-neural (anti-ceramide and anti-galactocerebroside antibodies and anti-mycobacterial antibodies were detected in ENL patients' sera as well, which were not related to the clinical course of disease. Our data suggest that bacterial killing is enhanced during reactions. Emergence of specific immune response to M. leprae and the effective role of TNF-alpha in mediating fragmentation of bacteria still need to be clarified.Dados recentes sugerem que o curso clínico dos estados reacionais

  3. Household costs of leprosy reactions (ENL in rural India.

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    David J Chandler

    2015-01-01

    Full Text Available Erythema nodosum leprosum (ENL is a common immune-mediated complication of lepromatous (LL and borderline lepromatous (BL leprosy. Most patients experience chronic or multiple acute ENL over many years during an economically active period of their lives. Understanding the economic burden of ENL is essential to provide effective patient support, yet this area has not been investigated.Ninety-one patients with LL or BL leprosy attending a leprosy hospital in Purulia district of West Bengal, India, were interviewed using a structured questionnaire. Cases (n = 53 were identified as those who had one or more episodes of ENL within the last 3 years. Controls (n = 38 had LL or BL leprosy but no history of ENL. Data were collected on household income, direct and indirect costs, and coping strategies.The total household cost was Rs 1543 per month or 27.9% (IQR 13.2-52.6 of monthly household income for cases, and Rs 237 per month or 4.9% (IQR 1.7-13.4 of monthly household income for controls. Indirect costs accounted for 65% of total household costs for cases. Direct costs accounted for the remaining 35% of household costs, and resulted almost entirely from treatment-seeking in the private sector. Total household costs exceeded 40% of household income for 37.7% of cases (n = 20 and 2.6% of controls (n = 1 [1 USD = 59 INR].Households affected by ENL face significant economic burden and are at risk of being pushed further into poverty. Health policy should acknowledge the importance of private sector provision and the significant contribution to total household costs of lost productivity (indirect cost. Further work is needed to explore this area and identify solutions.

  4. Expression of CD64 on Circulating Neutrophils Favoring Systemic Inflammatory Status in Erythema Nodosum Leprosum.

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    Veronica Schmitz

    2016-08-01

    Full Text Available Erythema Nodosum Leprosum (ENL is an immune reaction in leprosy that aggravates the patient´s clinical condition. ENL presents systemic symptoms of an acute infectious syndrome with high leukocytosis and intense malaise clinically similar to sepsis. The treatment of ENL patients requires immunosuppression and thus needs to be early and efficient to prevent both disabilities and permanent nerve damage. Some patients experience multiple episodes of ENL and prolonged use of immunosuppressive drugs may lead to serious adverse effects. Thalidomide treatment is extremely effective at ameliorating ENL symptoms. Several mechanisms have been proposed to explain the efficacy of thalidomide in ENL, including the inhibition of TNF production. Given its teratogenicity, thalidomide is prohibitive for women of childbearing age. A rational search for molecular targets during ENL episodes is essential to better understand the disease mechanisms involved, which may also lead to the discovery of new drugs and diagnostic tests. Previous studies have demonstrated that IFN-γ and GM-CSF, involved in the induction of CD64 expression, increase during ENL. The aim of the present study was to investigate CD64 expression during ENL and whether thalidomide treatment modulated its expression. Leprosy patients were allocated to one of five groups: (1 Lepromatous leprosy, (2 Borderline leprosy, (3 Reversal reaction, (4 ENL, and (5 ENL 7 days after thalidomide treatment. The present study demonstrated that CD64 mRNA and protein were expressed in ENL lesions and that thalidomide treatment reduced CD64 expression and neutrophil infiltrates-a hallmark of ENL. We also showed that ENL blood neutrophils exclusively expressed CD64 on the cell surface and that thalidomide diminished overall expression. Patient classification based on clinical symptoms found that severe ENL presented high levels of neutrophil CD64. Collectively, these data revealed that ENL neutrophils express CD64

  5. Rare Atypical Presentations in Type 2 Lepra Reaction: A Case Series

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    Mitra, Debdeep

    2017-01-01

    Abstract Background Leprosy or Hansen’s disease is a chronic mycobacterial infection caused by mycobacterium leprae. Reactions in Leprosy represent an acute inflammataory response during the natural chronic course of infection. Type 2 lepra reaction is a Th2-mediated type III hypersensitivity reaction in leprosy, with a characteristic cutaneous manifestation in the form of erythema nodosum leprosum (ENL). This presentation describes unusual presentations of Type 2 lepra reaction in five patie...

  6. Immune reconstitution inflammatory syndrome unmasking erythema nodosum leprosum: A rare case report

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    Geeta Kiran Arakkal

    2015-01-01

    Full Text Available Immune reconstitution inflammatory syndrome (IRIS occurs as an acute symptomatic expression of a latent infection during the recovery of immune system in response to antiretroviral therapy in HIV patients. IRIS triggers both opportunistic and non-opportunistic infections. We report a case of IRIS in a patient with HIV, presenting as erythema nodosum leprosum (ENL, which led to unmasking of lepromatous leprosy following anti-retroviral therapy (ART.

  7. Using methotrexate to treat patients with ENL unresponsive to steroids and clofazimine: a report on 9 patients.

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    Hossain, Delwar

    2013-03-01

    Erythema nodosum leprosum (ENL) is a chronic recurrent systemic complication of multi-bacillary leprosy frequently associated with the development of neuritis, iritis, orchitis, arthritis and dactylitis. It is well managed by thalidomide, but thalidomide is not available in Bangladesh. The World Health Organization recommends high doses of clofazimine and prednisolone. About 19% of patients do not respond completely to this regimen or experience relapse when reducing steroid dosage. We undertook this study to determine whether oral prednisolone combined with methotrexate was an effective and safe treatment regimen for individuals with ENL resistant to clofazimine and prednisolone. Between September, 2006-June, 2011, we treated nine resistant ENL patients with a combination of prednisolone and methotrexate for 24-36 months with a mean duration of 30 months. We observed improvement leading to persistent remission of ENL in all our patients. Adverse effects were mild weight gain, weight gain with facial swelling, folliculitis and extensive Pityriasis versicolor infection in one patient and crusted scabies in another. A combination of prednisolone and methotrexate was safe and effective in managing ENL not controlled by clofazimine and prednisolone.

  8. Double-blind trial of the efficacy of pentoxifylline vs thalidomide for the treatment of type II reaction in leprosy

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    A.M. Sales

    2007-02-01

    Full Text Available Type II reaction in leprosy, or erythema nodosum leprosum (ENL, is often characterized by severe clinical symptoms together with nerve function impairment leading to permanent disabilities. Thalidomide has been shown to be a highly effective drug for the treatment of ENL. It is, however, contraindicated for women of childbearing age due to its teratogenicity. On the other hand, pentoxifylline, used to treat hypercoagulable states, is not teratogenic and, like thalidomide, can inhibit the synthesis of tumor necrosis factor-a and other cytokines. In the present randomized double-blind clinical study we compared the effectiveness of orally administered pentoxifylline vs thalidomide in treating type II reaction in 44 patients. Daily doses of 300 mg thalidomide or 1.2 g pentoxifylline were administered for 30 days to multibacillary leprosy patients undergoing type II reaction. Randomly chosen patients were included in the study before, during, and after specific multidrug therapy. Clinical evaluations were performed on the 1st, 7th, 14th, 21st, and 30th days of treatment and laboratory tests were carried out on the 1st and 30th days. As expected, overall, thalidomide proved to be more effective in the treatment of type II leprosy reaction. Nevertheless, continuous treatment with pentoxifylline was effective in relieving the clinical signs of ENL, especially limb edema and systemic symptoms, in 62.5% of the patients.

  9. REACTIONAL STATES IN MULTIBACILLARY HANSEN DISEASE PATIENTS DURING MULTIDRUG THERAPY

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    José A.C. NERY

    1998-11-01

    Full Text Available It is well known that reactions are commonplace occurrences during the course of leprosy disease. Stigmatization may even be attributable to reactions which are also responsible for the worsening of neural lesions. A cohort of 162 newly-diagnosed baciloscopically positive patients from the Leprosy Care Outpatient Clinic of the Oswaldo Cruz Foundation (FIOCRUZ was selected for this study. While 46% of the multibacillary (MB patients submitted to the 24 fixed-dose multidrug therapy (MDT regimen suffered reactions during treatment, it was found that all MBs were susceptible and that constant attention and care were required at all times. Fourteen per cent were classified as BB, 52% as BL, and 33% as LL. None of the variables under study, such as, sex, age, clinical form, length of illness, length of dermatological lesions, baciloscopic index (BI, or degree of disability proved to be associate with reaction among the patients studied. Reversal Reaction (RR occurred in 45%, and Erythema Nodosum Leprosum (ENL occurred in 55%. Among BB patients who developed reactions (15 patients, 93% presented RR; while among the LL patients who developed reactions (34 patients, 91% presented ENL. Likewise, ENL was very frequent among those with disseminate lesions, while RR was most often observed in patients with segmentary lesions. RR was also most likely to occur during the initial months of treatment. It was demonstrated that the recurrence rate of ENL was significantly higher than that of RR. Neither grade of disability nor BI was shown to be associated with RR and ENL reaction. However, the RR rate was significantly higher among patients showing BI 3.Reações são ocorrências comuns no curso da hanseníase e são responsáveis pelo agravamento das lesões neurais. Uma coorte de 162 pacientes recém-diagnosticados, baciloscopicamente positivos, em acompanhamento no Ambulatório de Hanseníase da Fundação Oswaldo Cruz (FIOCRUZ foi selecionada para estudo

  10. Study of reproductive toxicity of Combretum leprosum Mart and ...

    African Journals Online (AJOL)

    Study of reproductive toxicity of Combretum leprosum Mart and Eicher in female Wistar rats. Jamylla Mirck Guerra de Oliveira, Denise Barbosa Santos, Francimarne Sousa Cardoso, Márcia de Sousa Silva, Yatta Linhares Boakari, Silvéria Regina de Sousa Lira, Amilton Paulo Raposo Costa ...

  11. Réaction sociale de la population vis-à-vis du phénomène d’enlèvement d’enfants à Abidjan / Social reaction of the population to the phenomenon of abduction of children in Abidjan

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    Okpo N.A.

    2017-12-01

    Full Text Available Cette étude vise à connaître la réaction des abidjanais en ce qui concerne l’enlèvement d’enfants. La théorie de la représentation sociale a été utilisée pour comprendre la réaction des abidjanais. Un questionnaire, des entretiens et l’observation ont permis de recueillir des données dont l’analyse indique une réaction négative, violente et l’exacerbation de la crainte. Celle-ci sous-entend la peur de la résurgence de l’enlèvement et des sacrifices humains qui dominent les pensées et angoissent les abidjanais. Ceux-ci multiplient alors les stratégies de sécurité aboutissant souvent à une réaction primitive et à une justice privée. This study aims to investigate the reaction of Abidjanese people to child abduction. The theory of social representation was used to understand their reaction. A questionnaire, some interviews and observations provided data the analysis of which indicates negative and violent reactions and intensified fear. This last implies the fear of the resurgence of the abduction and of the human sacrifices that dominate the thoughts and anguish Abidjanese people. This then leads to the increase of security strategies often leading to primitive reactions and to private justice.

  12. GERMINAÇAO DE SEMENTES DE Combretum leprosum MART.

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    MAURO VASCONCELOS PACHECO

    2014-01-01

    Full Text Available Combretum leprosum Mart. is a tree species native of the Caatinga, used in the restoration of degraded areas and in folk medicine. Thus, this research aimed to evaluate the germination and vigor of the seeds subjecting them to different pre-germinative treatments, temperatures and substrates. In the first experi- ment, we tested the pre-germinative treatments: mechanical scarification with sandpaper, chemical scarification with H2SO4 for 1, 5, 10 and 20 minutes, immersion in water at 80 oC and imbibition in distilled water for 24 hours, beyond of the control. In the second experiment, after treatment of imbibition in water for 24 hours, the experimental design was completely randomized in a factorial 5 x 4 (five substrates: into paper, sand, coconut fiber, vermiculite and paper towel organized in the form of rolls; and four temperatures: 25, 30, 35 and 20-30 oC. The following parameters were evalueted: seed moisture content, germination, germination speed index, first germination count and seedling length and dry matter weight. The seeds of Combretum leprosum have not coat dormancy. However, pre-germinative treatments of mechanical scarification with sandpaper and imbibi- tion in water for 24 hours allows better expression of seeds vigor. The paper towel and the temperatures of 25, 30 and 20-30 oC provide adequate conditions for evaluating the germination of Combretum leprosum seeds.

  13. Leprosy Reactions Show Increased Th17 Cell Activity and Reduced FOXP3+ Tregs with Concomitant Decrease in TGF-β and Increase in IL-6.

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    Chaman Saini

    2016-04-01

    Full Text Available 50% of leprosy patients suffer from episodes of Type 1/ reversal reactions (RR and Type 2/ Erythema Nodosum Leprosum (ENL reactions which lead to morbidity and nerve damage. CD4+ subsets of Th17 cells and CD25+FOXP3+ regulatory T cells (Tregs have been shown to play a major role in disease associated immunopathology and in stable leprosy as reported by us and others. The aim of our study was to analyze their role in leprosy reactions.Quantitative reverse transcribed PCR (qPCR, flowcytometry and ELISA were used to respectively investigate gene expression, cell phenotypes and supernatant levels of cytokines in antigen stimulated PBMC cultures in patients with stable disease and those undergoing leprosy reactions. Both types of reactions are associated with significant increase of Th17 cells and associated cytokines IL-17A, IL-17F, IL-21, IL-23 and chemokines CCL20, CCL22 as compared to matching stable forms of leprosy. Concurrently patients in reactions show reduction in FOXP3+ Treg cells as well as reduction in TGF-β and increase in IL-6. Moreover, expression of many T cell markers, cytokines, chemokines and signaling factors were observed to be increased in RR as compared to ENL reaction patients.Patients with leprosy reactions show an imbalance in Th17 and Treg populations. The reduction in Treg suppressor activity is associated withhigherTh17cell activity. The combined effect of reduced TGF-β and enhanced IL-6, IL-21 cytokines influence the balance between Th17 or Treg cells in leprosy reactions as reported in the murine models and autoimmune diseases. The increase in Th17 cell associated cytokines may contribute to lesional inflammation.

  14. Leprosy reactions: coinfections as a possible risk factor

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    Ana Carolina F. Motta

    2012-10-01

    Full Text Available OBJECTIVE: This study aimed to determine the frequency of coinfections in leprosy patients and whether there is a relationship between the presence of coinfections and the development of leprosy reactional episodes. METHOD: A cross-sectional study based on an analysis of the medical records of the patients who were treated at the Leprosy Clinics of the Ribeirão Preto Medical School, University of São Paulo, was conducted from 2000 to 2010. Information was recorded regarding the age, sex, clinical status, WHO classification, treatment, presence of reactions and coinfections. Focal and systemic infections were diagnosed based on the history, physical examination, and laboratory tests. Multinomial logistic regression was used to evaluate the associations between the leprosy reactions and the patients' gender, age, WHO classification and coinfections. RESULTS: Two hundred twenty-five patients were studied. Most of these patients were males (155/225 = 68.8% of an average age of 49.31±15.92 years, and the most prevalent clinical manifestation was the multibacillary (MB form (n = 146, followed by the paucibacillary (PB form (n = 79. Erythema nodosum leprosum (ENL was more prevalent (78/122 = 63.9% than the reversal reaction (RR (44/122 = 36.1%, especially in the MB patients (OR 5.07; CI 2.86-8.99; p<0.0001 who exhibited coinfections (OR 2.26; CI 1.56-3.27; p,<0.0001. Eighty-eight (88/225 = 39.1% patients exhibited coinfections. Oral coinfections were the most prevalent (40/88 = 45.5%, followed by urinary tract infections (17/88 = 19.3%, sinusopathy (6/88 = 6.8%, hepatitis C (6/88 = 6.8%, and hepatitis B (6/88 = 6.8%. CONCLUSIONS: Coinfections may be involved in the development and maintenance of leprosy reactions.

  15. Modelo para estimar a área foliar de Combretum leprosum Mart.

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    Willame dos Santos Candido

    2013-01-01

    Full Text Available Combretum leprosum Mart. -Combretaceae es un arbusto utilizado en la medicina popular del noreste de Brasil como antiulceroso, antihemorrágica y antinociceptiva. En este estudio se desarrolló un modelo para el cálculo de área foliar de Combretum leprosum usando mediciones lineales de longitud (C y ancho máximo (L de la hoja. Se recolectaron 200 láminas de hojas de una población de C. leprosum nativo en un área de conservación de la Caatinga en el campus de la Universidad Federal Rural de la Semi árido en Mossoro, Rio Grande do Norte. Las hojas se obtuvieron de árboles adultos y el área foliar se midió utilizando un integrador (LI-3100, LI-COR. El análisis de regresión se hizo con el programa SAEG. Para estimar el área foliar de C. leprosum se puede utilizar la ecuación lineal simple de regresión A = 0.7103 x (C x L, que es equivalente a tomar 71.03% de los productos de la longitud a lo largo de la nervadura central y el ancho máximo, con un coeficiente de determinación de 0.952617.

  16. Mechanitis polymnia casabranca and Ithomia lichyi lichyi (Lepidoptera: Nymphalidae) damaging tree of Solanum granuloso-leprosum (Solanaceae)

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    Tavares,Wagner de Souza; Pereira,Alexandre Igor de Azevedo; Mielke,Olaf Hermann Hendrik; Serrão,José Eduardo; Zanuncio,José Cola

    2014-01-01

    The Zona da Mata region is located in southeastern Minas Gerais State, Brazil with fauna and flora diversified, including herbivorous insects and Solanaceae plants. Ithomiinae caterpillars were observed damaging tree of Solanum granuloso-leprosum Dunal (Solanaceae), used for different purposes and abundant in secondary forest. The objective of this study was to identify defoliating caterpillars of S. granuloso-leprosum at the campus of Universidade Federal de Viçosa (UFV) in Viçosa, Minas Ger...

  17. Activity of the Lupane isolated from Combretum leprosum against Leishmania amazonensis promastigotes

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    Teles, Carolina B.G.; Silva-Jardim, Izaltina; Silva, Alexandre de A.E.; Zuliani, Juliana P.; Stabeli, Rodrigo G., E-mail: izaltina.jardim@pq.cnpq.b [Instituto de Pesquisas em Patologias Tropicais de Rondonia (IPEPATRO), Porto Velho, RO (Brazil); Moreira, Leandro S.; Facundo, Valdir A. [Universidade Federal de Rondonia, Porto Velho, RO (Brazil)

    2011-07-01

    This paper describes the activity of the ethanolic extract (EE), obtained from the fruits of Combretum leprosum, the triterpene 3{beta}, 6{beta}, 16{beta}-trihydroxylup-20(29)-ene (1) and its synthetic derivatives 1a-1d on Leishmania Amazonensis promastigotes. The EE displayed leishmanicidal activity and the IC{sub 50} was 24.8 {mu}g mL{sup -1}. However, the triterpene 3{beta}, 6{beta}, 16{beta}-trihydroxylup-20(29)-ene (1), at a concentration of 5.0 {mu}g mL{sup -1}, showed a potent inhibitory activity on promastigotes proliferation (IC{sub 50} = 3.3 {mu}g mL{sup -1}). Among the synthetic derivatives, only (1b) and (1d) were active against promastigotes (IC{sub 50} = 3.48 {mu}g mL{sup -1} and 5.8 {mu}g mL{sup -1}, respectively). Moreover, the synthetic derivative 1a showed no activity on promastigotes of L. Amazonensis. EE, (1) and the synthetic derivatives 1a-1d showed no cytotoxic effect on mice peritoneal macrophages. These results provide evidence that the ethanolic extract and the lupane isolated from C. leprosum was active against promastigotes of L. amazonensis, and may be used as a tool in the studies of new antileishmanial drugs. (author)

  18. Type 2 lepra reactions (ENL presenting with extensive cutaneous ulcerations

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    Sapnashree Budhnoor Sreekantaiah

    2012-01-01

    Full Text Available A 45 year old lady presented with multiple painful necrotic ulcerations over the trunk, arms, thighs and gluteal areas of two months duration. She also had erythematous papules and pustules over the face since 1 week. History of recurrent papular lesions, some of them undergoing ulceration were present since 3 years. All biochemical parameters were within normal limits. Rheumatoid factor, ANA, Elisa for HIV and VDRL were negative. Pus culture showed growth of Staphylococcus aureus. Smear for AFB showed multiple globi. Skin biopsy showed atrophic epidermis with grenz zone; dermis showed sheets of foamy macrophages and oedematous blood vessels infiltrated with neutrophils and ocasional plasma cells. Patient was admitted and was started on MDT-MB along with thalidomide and prednisolone.

  19. Mechanitis polymnia casabranca and Ithomia lichyi lichyi (Lepidoptera: Nymphalidae damaging tree of Solanum granuloso-leprosum (Solanaceae

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    Wagner de Souza Tavares

    2014-03-01

    Full Text Available The Zona da Mata region is located in southeastern Minas Gerais State, Brazil with fauna and flora diversified, including herbivorous insects and Solanaceae plants. Ithomiinae caterpillars were observed damaging tree of Solanum granuloso-leprosum Dunal (Solanaceae, used for different purposes and abundant in secondary forest. The objective of this study was to identify defoliating caterpillars of S. granuloso-leprosum at the campus of Universidade Federal de Viçosa (UFV in Viçosa, Minas Gerais State, Brazil and review host plants of Mechanitis polymnia L., 1758 (Lepidoptera: Nymphalidae. Thirteen caterpillars found damaging a tree of S. granuloso-leprosum at the campus of UFV were collected and maintained in the Laboratório de Controle Biológico de Insetos (LCBI from UFV until adult emergence. These caterpillars were of two species, being ten of the first and three of the second species. Adult specimens of the latter species were identified as Ithomia lichyi lichyi D'Almeida, 1939 (Lepidoptera: Nymphalidae in the Departamento de Zoologia of Universidade Federal do Paraná (UFPR in Curitiba, Paraná State, Brazil and of the group of ten caterpillars as Mechanitis polymnia casabranca Haensch, 1905 (Lepidoptera: Nymphalidae in the Museu de Zoologia of Universidade de São Paulo (USP in São Paulo State, Brazil. This is the first report of M. polymnia casabranca and I. lichyi lichyi together damaging plant of S. granuloso-leprosum in the Zona da Mata region of Minas Gerais State, Brazil and 57 plants are recorded as host of M. polymnia.

  20. Simultaneous localization of MLL, AF4 and ENL genes in interphase nuclei by 3D-FISH: MLL translocation revisited

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    Sun Jian-Sheng

    2006-01-01

    Full Text Available Abstract Background Haematological cancer is characterised by chromosomal translocation (e.g. MLL translocation in acute leukaemia and two models have been proposed to explain the origins of recurrent reciprocal translocation. The first, established from pairs of translocated genes (such as BCR and ABL, considers the spatial proximity of loci in interphase nuclei (static "contact first" model. The second model is based on the dynamics of double strand break ends during repair processes (dynamic "breakage first" model. Since the MLL gene involved in 11q23 translocation has more than 40 partners, the study of the relative positions of the MLL gene with both the most frequent partner gene (AF4 and a less frequent partner gene (ENL, should elucidate the MLL translocation mechanism. Methods Using triple labeling 3D FISH experiments, we have determined the relative positions of MLL, AF4 and ENL genes, in two lymphoblastic and two myeloid human cell lines. Results In all cell lines, the ENL gene is significantly closer to the MLL gene than the AF4 gene (with P value loci would indicate a greater probability of the occurrence of t(11;19(q23;p13.3 compared to t(4;11(q21;q23. However this is in contradiction to the epidemiology of 11q23 translocation. Conclusion The simultaneous multi-probe hybridization in 3D-FISH is a new approach in addressing the correlation between spatial proximity and occurrence of translocation. Our observations are not consistent with the static "contact first" model of translocation. The recently proposed dynamic "breakage first" model offers an attractive alternative explanation.

  1. Simultaneous localization of MLL, AF4 and ENL genes in interphase nuclei by 3D-FISH: MLL translocation revisited

    International Nuclear Information System (INIS)

    Gué, Michaël; Sun, Jian-Sheng; Boudier, Thomas

    2006-01-01

    Haematological cancer is characterised by chromosomal translocation (e.g. MLL translocation in acute leukaemia) and two models have been proposed to explain the origins of recurrent reciprocal translocation. The first, established from pairs of translocated genes (such as BCR and ABL), considers the spatial proximity of loci in interphase nuclei (static 'contact first' model). The second model is based on the dynamics of double strand break ends during repair processes (dynamic 'breakage first' model). Since the MLL gene involved in 11q23 translocation has more than 40 partners, the study of the relative positions of the MLL gene with both the most frequent partner gene (AF4) and a less frequent partner gene (ENL), should elucidate the MLL translocation mechanism. Using triple labeling 3D FISH experiments, we have determined the relative positions of MLL, AF4 and ENL genes, in two lymphoblastic and two myeloid human cell lines. In all cell lines, the ENL gene is significantly closer to the MLL gene than the AF4 gene (with P value < 0.0001). According to the static 'contact first' model of the translocation mechanism, a minimal distance between loci would indicate a greater probability of the occurrence of t(11;19)(q23;p13.3) compared to t(4;11)(q21;q23). However this is in contradiction to the epidemiology of 11q23 translocation. The simultaneous multi-probe hybridization in 3D-FISH is a new approach in addressing the correlation between spatial proximity and occurrence of translocation. Our observations are not consistent with the static 'contact first' model of translocation. The recently proposed dynamic 'breakage first' model offers an attractive alternative explanation

  2. Acute myeloid leukemia induced by MLL-ENL is cured by oncogene ablation despite acquisition of complex genetic abnormalities.

    Science.gov (United States)

    Horton, Sarah J; Walf-Vorderwülbecke, Vanessa; Chatters, Steve J; Sebire, Neil J; de Boer, Jasper; Williams, Owen

    2009-05-14

    Chromosomal translocations involving 11q23 are frequent in infant acute leukemia and give rise to the formation of MLL fusion genes. The mechanism of leukemic transformation by these fusions has been the subject of numerous investigations. However, the dependence of acute leukemia on MLL fusion activity in vivo and the efficacy of targeting this activity to eliminate disease have not been established. We have developed a model for conditional expression of MLL-ENL in hematopoietic progenitor cells, in which expression of the fusion oncogene is turned off by doxycycline. Conditionally immortalized myeloblast cells derived from these progenitors were found to induce leukemia in vivo. Leukemic cells isolated from primary recipient mice were shown to have acquired additional genetic abnormalities and, when transplanted into secondary recipients, induced leukemia with shortened latencies. However, the leukemic cells remained dependent on MLL-ENL expression in vitro and in vivo, and its ablation resulted in regression of established leukemias. This study demonstrates that even genetically complex leukemias can be reversed on inactivation of the initiating MLL fusion and has important implications for the design of novel leukemia therapies.

  3. La rondelle au bison d'enlène (Montesquieu-Avantès, Ariège

    Directory of Open Access Journals (Sweden)

    R. BÉGOUËN

    2009-10-01

    Full Text Available Une rondelle perforée en os, hors du commun par son décor, a été mise au jour dans une couche du Magdalénien moyen de la grotte d'Enléne. Sur la moitié d'une face un bison entier a été gravé. L'autre face présente un décor beaucoup plus fruste et n'était vraisemblablement pas destinée a étre vue. Cette rondelle, caractéristique du Magdalénien moyen, est replacée par les auteurs dans le contexte des objets de méme nature connus en France et dans les Asturies.

  4. Características biométricas e descrição morfológica de frutos, sementes e plântulas de Combretum leprosum Mart.

    Directory of Open Access Journals (Sweden)

    Renan da Cruz Paulino

    2013-10-01

    Full Text Available 800x600 O mofumbo (Combretum leprosum Mart. é uma planta com uso na apicultura, medicina popular, forrageira, e com grande potencial na recuperação de áreas degradadas, principalmente por ser resistente a queimadas e cortes. Foram conduzidos estudos visando a caracterizar frutos, sementes, plântulas, mudas, germinação e emergência de Combretum leprosum. Foram realizadas medições de frutos e sementes, com paquímetro digital; massa de 1000 frutos e 1000 sementes, em balança semi-analítica; teor de umidade das sementes, pelo método de estufa a 105±3ºC por 24hs; 100 sementes foram colocadas para germinar em bandeja de germinação contendo fibra de coco para descrição da germinação e confecção das ilustrações. A unidade de dispersão é o fruto, seco, indeiscente, castanho, do tipo betulídio com uma semente por fruto. A semente é monospérmica com 4 estrias longitudinais; peso de mil sementes é 117,3g com 11,5% de umidade. A germinação é hipógea criptocotiledonar, com cotilédones de armazenamento. Protófilos e metáfilos apresentam diferenças na filotaxia. Os resultados obtidos podem ser empregados na identificação taxonômica e em trabalhos de tecnologia de sementes. Normal 0 21 false false false PT-BR X-NONE X-NONE MicrosoftInternetExplorer4

  5. Purification and characterization of a new cold active lipase, EnL A ...

    African Journals Online (AJOL)

    SONU

    2015-06-03

    Jun 3, 2015 ... analysis using GC-MS and Fourier transform infrared (FTIR) spectroscopy. Lanka and Latha 1899. GC-MS analysis for FAME's. Fatty acid methyl esters (FAME) content in the reaction mixture was analyzed using GCMSQP2010, SHIMADZU instrument equipped with a ZB-5ms column with 30 m length, 0.25 ...

  6. Vitamin D receptor expression levels determine the severity and complexity of disease progression among leprosy reaction patients

    Directory of Open Access Journals (Sweden)

    D. Mandal

    2015-07-01

    Full Text Available We studied the roles of vitamin D and its receptor, VDR, in the progression of leprosy. The majority of individuals with leprosy from Kolkata, India, with a type 1 or type 2 reaction have low levels of vitamin D3 in serum samples. Interestingly, individuals with a type 2 reaction associated with neuritis/erythema nodosum leprosum had very low VDR mRNA expression levels, ranging from 5% to 10%, compared to that of healthy control subjects; these patients also had a high bacilli index, ranging from 3+ to 5+. This is the first report to indicate that VDR expression levels may determine the complexity and severity of the progression of leprosy.

  7. Analysis of energy poverty in the light of the 2013 National Housing Survey (ENL). Energy poverty in the light of the 2013 National Housing Survey - Synthesis

    International Nuclear Information System (INIS)

    Bernard, Charles-Andre; Teissier, Olivier

    2016-01-01

    This study is based on the results of the French national housing survey (ENL, Enquete Nationale Logement) of 2013 which gives information on the housing stock and on tenure conditions for households in their primary residence. After a brief presentation of this source and of its limitations, this study aims at characterising households in a situation of energy poverty according to indicators defined by the ONPE (national observatory of energy poverty), and at assessing their dwelling conditions. It also aims at highlighting the different aspects of the phenomenon of energy poverty. Evolutions of indicators are considered on the 1996-2013 period, based on the survey results in 1996, 2002, 2006 and 2013. After a recall of the ONPE indicators, the authors discuss statistic results related to these indicators, try to assess the severity of the energy poverty phenomenon, and the impact of the 'energy check'. Social-economic characteristics of households are presented in a table and discussed, as well as housing characteristics, the case of social housing, some behavioural characteristics of households, financial supports for works and works performed by occupying owners. The next part comments evolutions of indicators, their continuities and deviations, by examining their sensitivity to energy prices, and their evolution in time. A synthesis of results is proposed and lessons learned are finally discussed. Appendices address various issues (factors influencing a statement of the cold, methodologies of calculation of indicators), and propose additional results, and values of indicators in time

  8. Circulating levels of insulin-like growth factor-I (IGF-I correlate with disease status in leprosy

    Directory of Open Access Journals (Sweden)

    Rodrigues Luciana

    2011-12-01

    Full Text Available Abstract Background Caused by Mycobacterium leprae (ML, leprosy presents a strong immune-inflammatory component, whose status dictates both the clinical form of the disease and the occurrence of reactional episodes. Evidence has shown that, during the immune-inflammatory response to infection, the growth hormone/insulin-like growth factor-I (GH/IGF-I plays a prominent regulatory role. However, in leprosy, little, if anything, is known about the interaction between the immune and neuroendocrine systems. Methods In the present retrospective study, we measured the serum levels of IGF-I and IGBP-3, its major binding protein. These measurements were taken at diagnosis in nonreactional borderline tuberculoid (NR BT, borderline lepromatous (NR BL, and lepromatous (NR LL leprosy patients in addition to healthy controls (HC. LL and BL patients who developed reaction during the course of the disease were also included in the study. The serum levels of IGF-I, IGFBP-3 and tumor necrosis factor-alpha (TNF-α were evaluated at diagnosis and during development of reversal (RR or erythema nodosum leprosum (ENL reaction by the solid phase, enzyme-labeled, chemiluminescent-immunometric method. Results The circulating IGF-I/IGFBP-3 levels showed significant differences according to disease status and occurrence of reactional episodes. At the time of leprosy diagnosis, significantly lower levels of circulating IGF-I/IGFBP-3 were found in NR BL and NR LL patients in contrast to NR BT patients and HCs. However, after treatment, serum IGF-I levels in BL/LL patients returned to normal. Notably, the levels of circulating IGF-I at diagnosis were low in 75% of patients who did not undergo ENL during treatment (NR LL patients in opposition to the normal levels observed in those who suffered ENL during treatment (R LL patients. Nonetheless, during ENL episodes, the levels observed in RLL sera tended to decrease, attaining similar levels to those found in NR LL patients

  9. Serum uric acid levels during leprosy reaction episodes

    Directory of Open Access Journals (Sweden)

    Yvelise T. Morato-Conceicao

    2016-03-01

    Full Text Available Background. Leprosy reactions are acute inflammatory episodes that occur mainly in the multibacillary forms of the disease. The reactions are classified as type 1 (reverse reaction or type 2 (erythema nodosum leprosum. Leprosy-associated oxidative stress has been widely demonstrated. Several recent studies have shown uric acid (UA to have antioxidative effects under pathologic conditions. The objective of this study was to assess serum levels of UA in patients with leprosy reactions, with the aim of monitoring their levels before and after treatment, compared with levels in leprosy patients without reactions. Methods. The study included patients aged 18–69 years assisted at a leprosy treatment reference center in the Central Region of Brazil. Patients who were pregnant; were using immunosuppressant drugs or immunobiologicals; or had an autoimmune disease, human immunodeficiency virus infection, acquired immune deficiency syndrome, or tuberculosis were excluded. Upon recruitment, all individuals were clinically assessed for skin lesions and neural or systemic impairment. Some patients had already completed treatment for leprosy, while others were still undergoing treatment or had initiated treatment after being admitted. The treatment of the reactional episode was started only after the initial evaluation. Laboratory assessments were performed upon admission (baseline and at approximately 30 and 60 days (time points 1 and 2, respectively. Results. A total of 123 leprosy patients were recruited between June 2012 and June 2015; among them, 56, 42, and 25 presented with type 1, type 2, and no reactions, respectively. Serum UA levels were significantly reduced in patients with type 2 leprosy reactions compared with patients in the control group and remained lower in the two subsequent assessments, after initiation of anti-reaction treatments, with similar values to those recorded before the treatment. Discussion. The decreased serum UA levels in

  10. Reaction Automata

    OpenAIRE

    Okubo, Fumiya; Kobayashi, Satoshi; Yokomori, Takashi

    2011-01-01

    Reaction systems are a formal model that has been introduced to investigate the interactive behaviors of biochemical reactions. Based on the formal framework of reaction systems, we propose new computing models called reaction automata that feature (string) language acceptors with multiset manipulation as a computing mechanism, and show that reaction automata are computationally Turing universal. Further, some subclasses of reaction automata with space complexity are investigated and their la...

  11. Nuclear reactions

    International Nuclear Information System (INIS)

    Lane, A.M.

    1980-01-01

    In reviewing work at Harwell over the past 25 years on nuclear reactions it is stated that a balance has to be struck in both experiment and theory between work on cross-sections of direct practical relevance to reactors and on those relevant to an overall understanding of reaction processes. The compound nucleus and direct process reactions are described. Having listed the contributions from AERE, Harwell to developments in nuclear reaction research in the period, work on the optical model, neutron capture theory, reactions at doorway states with fine structure, and sum-rules for spectroscopic factors are considered in more detail. (UK)

  12. Estudo da toxicidade reprodutiva de Combretum leprosum Mart ...

    African Journals Online (AJOL)

    *

    2013-04-17

    Apr 17, 2013 ... albino rats. Indian. J. Med. Res. 58(9):1285-9. Ghandi M, Lal R, Sankaranarayanan A, Sharma PL (1991). Post-coital antifertility activity of Ruta gravoleolens in female rats and hamsters. J. Ethnopharmacol. 34: 49-59. Goodman HM (1994). Basic medical endocrinology. 2 ed. New York;. Raven Press, p.299.

  13. Transesophageal echocardiography. 3. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Lambertz, Heinz; Lethen, Harald

    2013-01-01

    The book on transesophageal echocardiography covers the following issues: Development of transesophageal echocardiography, technical advances; indications and contraindication for transesophageal echocardiography; systematic of the medical examination process; cardiac valves and valve prostheses; mitral and aortic valvuloplasty, TAVI and interventional treatment of mitral regurgitation; infectious endocarditis; one-way and effluence disturbances of the left and right ventricle; diseases of the thoracic aorta; undefined right ventricle enlargement; lung embolism, acute infarct complications; TEE during anesthesia and perioperative intensive medicine, cardiac sources of embolism; cardiac tumors, mediastinal lymph nodes; pericardiac diseases; congenital heart diseases in childhood and adulthood; catheter interventions and heart valve reconstruction; surgically corrected congenital cardiac defects; intracavitary versus transesophageal echocardiography; three-dimensional TEE; coronary diagnostics; ischemia and vitality diagnostics.

  14. Reaction mechanisms

    International Nuclear Information System (INIS)

    Nguyen Trong Anh

    1988-01-01

    The 1988 progress report of the Reaction Mechanisms laboratory (Polytechnic School, France), is presented. The research topics are: the valence bond methods, the radical chemistry, the modelling of the transition states by applying geometric constraints, the long range interactions (ion - molecule) in gaseous phase, the reaction sites in gaseous phase and the mass spectroscopy applications. The points of convergence between the investigations of the mass spectroscopy and the theoretical chemistry teams, as well as the purposes guiding the research programs, are discussed. The published papers, the conferences, the congress communications and the thesis, are also reported [fr

  15. Capture reactions

    NARCIS (Netherlands)

    Endt, P.M.

    1956-01-01

    Capture reactions will be considered here from the viewpoint of the nuclear spectroscopist. Especially important to him are the capture of neutrons, protons, and alpha particles, which may proceed through narrow resonances, offering a well defined initial state for the subsequent deexcitation

  16. Allergic reactions

    Science.gov (United States)

    ... that don't bother most people (such as venom from bee stings and certain foods, medicines, and pollens) can ... person. If the allergic reaction is from a bee sting, scrape the ... more venom. If the person has emergency allergy medicine on ...

  17. cycloaddition reactions

    Indian Academy of Sciences (India)

    Unknown

    ... has shown very severe limitations in predicting the regioselectivity. In comparison,. DFT-based descriptors are better suited to model the regioselectivity of cycloaddition reactions. Acknowledgements. GG thanks the Council of Scientific and Industrial. Research for a fellowship. References. 1. Winkler J D 1996 Chem. Rev.

  18. Spallation reactions

    International Nuclear Information System (INIS)

    Cugon, J.

    1996-01-01

    Spallation reactions dominate the interactions of hadrons with nuclei in the GeV range (from ∼ 0.1 to ∼ 10 GeV). They correspond to a sometimes important ejection of light particles leaving most of the time a residue of mass commensurate with the target mass. The main features of the experimental data are briefly reviewed. The most successful theoretical model, namely the intranuclear cascade + evaporation model, is presented. Its physical content, results and possible improvements are critically discussed. Alternative approaches are shortly reviewed. (author)

  19. Nuclear reactions

    International Nuclear Information System (INIS)

    Corner, J.; Richardson, K.; Fenton, N.

    1990-01-01

    Nuclear reactions' marks a new development in the study of television as an agency of public policy debate. During the Eighties, nuclear energy became a major international issue. The disasters at Three-mile Island and Chernobyl created a global anxiety about its risks and a new sensitivity to it among politicians and journalists. This book is a case-study into documentary depictions of nuclear energy in television and video programmes and into the interpretations and responses of viewers drawn from many different occupational groupings. How are the complex and specialist arguments about benefit, risk and proof conveyed through the different conventions of commentary, interview and film sequence? What symbolic associations does the visual language of television bring to portrayals of the issue? And how do viewers make sense of various and conflicting accounts, connecting what they see and hear on the screen with their pre-existing knowledge, experience and 'civic' expectations. The authors examine some of the contrasting forms and themes which have been used by programme makers to explain and persuade, and then give a sustained analysis of the nature and sources of viewers' own accounts. 'Nuclear Reactions' inquires into the public meanings surrounding energy and the environment, spelling out in its conclusion some of the implications for future media treatments of this issue. It is also a key contribution to the international literature on 'television knowledge' and the processes of active viewing. (author)

  20. Hypnotherapy: A useful adjunctive therapeutic modality in hansen′s disease

    Directory of Open Access Journals (Sweden)

    E N Abdul Latheef

    2014-01-01

    Full Text Available Hypnotherapy is a useful adjunctive psychotherapeutic procedure used in various conditions such as pain disorders, atopic dermatitis, and alopecia areata. However, it is less utilized in the field of dermatology. Only limited data exist on its role in the management of various skin diseases. There is dearth of literature on the role of hypnotherapy in Hansen′s disease (HD. We report two cases of HD, one with very resistant neuralgia and the other with recurrent erythema nodosum leprosum (ENL. Both the patients were assessed using hospital anxiety and depression scale, dermatology life quality index and the neuralgia was assessed using the visual analog scale. Three sessions of hypnotherapy were given to both the patients. There was dramatic improvement in the incidence of ENL and neuralgia and we could rapidly reduce the dose of drugs used for both conditions.

  1. Chain reaction

    International Nuclear Information System (INIS)

    Balogh, Brian.

    1991-01-01

    Chain Reaction is a work of recent American political history. It seeks to explain how and why America came to depend so heavily on its experts after World War II, how those experts translated that authority into political clout, and why that authority and political discretion declined in the 1970s. The author's research into the internal memoranda of the Atomic Energy Commission substantiates his argument in historical detail. It was not the ravages of American anti-intellectualism, as so many scholars have argued, that brought the experts back down to earth. Rather, their decline can be traced to the very roots of their success after World War II. The need to over-state anticipated results in order to garner public support, incessant professional and bureaucratic specialization, and the sheer proliferation of expertise pushed arcane and insulated debates between experts into public forums at the same time that a broad cross section of political participants found it easier to gain access to their own expertise. These tendencies ultimately undermined the political influence of all experts. (author)

  2. Estimation of serum level of interleukin-17 and interleukin-4 in leprosy, towards more understanding of leprosy immunopathogenesis

    Directory of Open Access Journals (Sweden)

    Marwa Abdallah

    2013-01-01

    Full Text Available Background: Combating Mycobacterium leprae is known to be via T-helper1 response. However, other T-helper effector cells; T-helper17 and T-helper2; play a role, particularly in the context of disease type. Aims: We aimed to evaluate serum levels of interleukin (IL-17 (T-helper17 cytokine and IL-4 (T-helper2 cytokine in untreated patients with different types of leprosy, compared to controls. Methods: Using enzyme-linked immunosorbent assay, serum IL-17 and IL-4 levels were estimated in 43 leprotic patients and 43 controls. Patients were divided into six groups; tuberculoid, borderline cases, lepromatous, erythema nodosum leprosum (ENL, type 1 reactional leprosy, and pure neural leprosy. Patients were also categorized according to bacillary load and the presence or absence of reactions. Results: Serum IL-17 was significantly lower in cases (4-61.5 pg/mL; median 19, compared to controls (26-55 pg/mL; median 36 (P < 0.001, and was significantly lower in each type of leprosy compared to controls, with the lowest level in lepromatous leprosy (4-61.5 pg/mL; median 12.5. Significantly elevated serum IL-4 was found in patients (1.31-122.4 pg/mL; median 2.31 compared to controls (1.45-5.72 pg/mL; median 2.02 (P = 0.008, with the highest level among lepromatous leprosy patients (2-87.2 pg/mL; median 28.9, and the lowest in type 1 reactional leprosy (1.4-2.5 pg/mL; median 1.87 (P = 0.006. Conclusion: Defective secretion of IL-17 is related to disease acquisition as well as progression toward lepromatous pole in leprosy patients. The overproduction of IL-4 in patients with lepromatous leprosy may infer their liability to develop ENL. Nevertheless, the small number of the studied population is a limitation.

  3. Catalysis of Photochemical Reactions.

    Science.gov (United States)

    Albini, A.

    1986-01-01

    Offers a classification system of catalytic effects in photochemical reactions, contrasting characteristic properties of photochemical and thermal reactions. Discusses catalysis and sensitization, examples of catalyzed reactions of excepted states, complexing ground state substrates, and catalysis of primary photoproducts. (JM)

  4. On Thermonuclear Reaction Rates

    OpenAIRE

    Haubold, H. J.; Mathai, A. M.

    1996-01-01

    Nuclear reactions govern major aspects of the chemical evolution of galaxies and stars. Analytic study of the reaction rates and reaction probability integrals is attempted here. Exact expressions for the reaction rates and reaction probability integrals for nuclear reactions in the cases of nonresonant, modified nonresonant, screened nonresonant and resonant cases are given. These are expressed in terms of H-functions, G-functions and in computable series forms. Computational aspects are als...

  5. [Adverse reactions to insulin].

    Science.gov (United States)

    Liñana, J J; Montoro, F J; Hernández, M D; Basomba, A

    1997-07-01

    The prevalence of allergic reactions to insuline has decreased during the last few years. Probably this is due to the use of the newly-developed recombinant human insuline. At present, adverse reactions to insuline occur in 5-10% of patients on therapy with insuline. Adverse reactions may be local (more frequent) or systemic (rare). Insuline resistance consists in a different type of immunological reaction. Diagnosis of allergy to insuline is based on clinical history and cutaneous and serological tests. Treatment depends upon the severity of the reaction. When insuline is indispensable despite a previous allergic reaction, a desensitization protocol may be implemented.

  6. Preequilibrium Nuclear Reactions

    International Nuclear Information System (INIS)

    Strohmaier, B.

    1988-01-01

    After a survey on existing experimental data on precompound reactions and a description of preequilibrium reactions, theoretical models and quantum mechanical theories of preequilibrium emission are presented. The 25 papers of this meeting are analyzed separately

  7. Microfluidic chemical reaction circuits

    Science.gov (United States)

    Lee, Chung-cheng [Irvine, CA; Sui, Guodong [Los Angeles, CA; Elizarov, Arkadij [Valley Village, CA; Kolb, Hartmuth C [Playa del Rey, CA; Huang, Jiang [San Jose, CA; Heath, James R [South Pasadena, CA; Phelps, Michael E [Los Angeles, CA; Quake, Stephen R [Stanford, CA; Tseng, Hsian-rong [Los Angeles, CA; Wyatt, Paul [Tipperary, IE; Daridon, Antoine [Mont-Sur-Rolle, CH

    2012-06-26

    New microfluidic devices, useful for carrying out chemical reactions, are provided. The devices are adapted for on-chip solvent exchange, chemical processes requiring multiple chemical reactions, and rapid concentration of reagents.

  8. Oral Hypersensitivity Reactions

    Science.gov (United States)

    ... such as cinnamon, peppermint, eugenol and menthol. Even dental floss and denture cleansers may contain ingredients known to cause a hypersensitivity reaction. Q: How can dental treatment trigger a hypersensitivity reaction? A: Some dental ...

  9. Chemical transport reactions

    CERN Document Server

    Schäfer, Harald

    2013-01-01

    Chemical Transport Reactions focuses on the processes and reactions involved in the transport of solid or liquid substances to form vapor phase reaction products. The publication first offers information on experimental and theoretical principles and the transport of solid substances and its special applications. Discussions focus on calculation of the transport effect of heterogeneous equilibria for a gas motion between equilibrium spaces; transport effect and the thermodynamic quantities of the transport reaction; separation and purification of substances by means of material transport; and

  10. Thermonuclear reaction rates. III

    International Nuclear Information System (INIS)

    Harris, M.J.; Fowler, W.A.; Caughlan, G.R.; Zimmerman, B.A.

    1983-01-01

    Stellar thermonuclear reaction rates are revised and updated, adding a number of new important reaction rates. Several reactions with large negative Q-values are included, and examples of them are discussed. The importance of the decay rates for Mg-26(p,n) exp 26 Al and Al-26(n,p) exp 26 Mg for stellar studies is emphasized. 19 references

  11. Cluster knockout reactions

    Indian Academy of Sciences (India)

    2014-04-07

    Apr 7, 2014 ... advancements in the area of (α, 2α) reactions and heavy cluster knockout reactions are discussed. Importance of the finite-range vertex and the final-state interactions are brought out. Keywords. Cluster knockout reactions; FR-DWIA calculations; t-matrix effective interaction. PACS Nos 14.20.Pt; 24.10.

  12. ORGANIC REACTION MECHANISM CONTROVERSY ...

    African Journals Online (AJOL)

    Preferred Customer

    However, there are so many chemical reactions notably in organic chemistry where reactions may not directly lead to products. ... There are concepts that support these ideas but can they be proven to the ... Reaction mechanism is one such issue in organic chemistry that has attracted a lot of controversial comments from ...

  13. Maillard Reaction: review

    Directory of Open Access Journals (Sweden)

    Júlia d'Almeida Francisquini

    2017-11-01

    Full Text Available Maillard reaction is an important subject of study in food science and technology and different areas of knowledge are involved such as chemistry, food engineering, nutrition and food technology. The objective of this paper is to present the basic concepts of the Maillard reaction, such as the reaction stages, the main compounds producced and some technological consequences for dairy products.

  14. Resonant thermonuclear reaction rate

    International Nuclear Information System (INIS)

    Haubold, H.J.; Mathai, A.M.

    1986-01-01

    Basic physical principles for the resonant and nonresonant thermonuclear reaction rates are applied to find their standard representations for nuclear astrophysics. Closed-form representations for the resonant reaction rate are derived in terms of Meijer's G-function. Analytic representations of the resonant and nonresonant nuclear reaction rates are compared and the appearance of Meijer's G-function is discussed in physical terms

  15. Nuclear reaction studies

    International Nuclear Information System (INIS)

    Alexander, J.M.; Lacey, R.A.

    1994-01-01

    Research focused on the statistical and dynamical properties of ''hot'' nuclei formed in symmetric heavy-ion reactions. Theses included ''flow'' measurements and the mechanism for multifragment disassembly. Model calculations are being performed for the reactions C+C, Ne+Al, Ar+Sc, Kr+Nb, and Xe+La. It is planned to study 40 Ar reactions from 27 to 115 MeV/nucleon. 2 figs., 41 refs

  16. Sleeve reaction chamber system

    Science.gov (United States)

    Northrup, M Allen [Berkeley, CA; Beeman, Barton V [San Mateo, CA; Benett, William J [Livermore, CA; Hadley, Dean R [Manteca, CA; Landre, Phoebe [Livermore, CA; Lehew, Stacy L [Livermore, CA; Krulevitch, Peter A [Pleasanton, CA

    2009-08-25

    A chemical reaction chamber system that combines devices such as doped polysilicon for heating, bulk silicon for convective cooling, and thermoelectric (TE) coolers to augment the heating and cooling rates of the reaction chamber or chambers. In addition the system includes non-silicon-based reaction chambers such as any high thermal conductivity material used in combination with a thermoelectric cooling mechanism (i.e., Peltier device). The heat contained in the thermally conductive part of the system can be used/reused to heat the device, thereby conserving energy and expediting the heating/cooling rates. The system combines a micromachined silicon reaction chamber, for example, with an additional module/device for augmented heating/cooling using the Peltier effect. This additional module is particularly useful in extreme environments (very hot or extremely cold) where augmented heating/cooling would be useful to speed up the thermal cycling rates. The chemical reaction chamber system has various applications for synthesis or processing of organic, inorganic, or biochemical reactions, including the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction.

  17. Sodium-concrete reactions

    International Nuclear Information System (INIS)

    Gadd, P.G.

    1982-09-01

    Reaction products of all the major constituents of commercial concrete with liquid sodium have been identified using X-Ray Powder Diffraction. Eight different aggregate materials were chosen to represent the main rock classes available and Ordinary Portland Cement was used throughout. A Differential Thermal Analysis apparatus which enabled continuous stirring of the reactants was designed to improve contact between the powdered concrete components and the liquid sodium. Heats of reaction were calculated from peak areas, the apparatus having been calibrated using reactions of sodium with simple binary oxides whose heats of reaction were known. The heat evolution from aggregates was rationalised on the basis of their mineralogical composition, thus providing a means of choosing an optimum aggregate for use in the concrete of a LMFBR. The reaction of SiO 2 with liquid sodium was shown to depend on the oxygen concentration of the sodium. Reaction products are identified. The reaction of Al 2 O 3 with sodium has been shown also to depend on the oxygen concentration. Reaction products are identified. The evolution of hydrogen during a sodium-cement reaction has been studied using an electrochemical hydrogen meter and the penetration of the liquid metal into cement blocks was also investigated. (author)

  18. Tattoo reaction: Case series

    Directory of Open Access Journals (Sweden)

    Muneer Mohamed

    2018-04-01

    Full Text Available Tattoo is going to be a very common practice especially among young people and we are witnessing a gradual increase of numerous potential complications to tattoo placement which are often seen by physicians, but generally unknown to the public. The most common skin reactions to tattoo include a transient acute inflammatory reaction due to trauma of the skin with needles and medical complications such as superficial and deep local infections, systemic infections, allergic contact dermatitis, photodermatitis, granulomatous and lichenoid reactions, and skin diseases localized on tattooed area (eczema, psoriasis, lichen, and morphea. In this series we present three cases of tattoo reaction.

  19. Clock Reaction: Outreach Attraction

    Science.gov (United States)

    Carpenter, Yuen-ying; Phillips, Heather A.; Jakubinek, Michael B.

    2010-01-01

    Chemistry students are often introduced to the concept of reaction rates through demonstrations or laboratory activities involving the well-known iodine clock reaction. For example, a laboratory experiment involving thiosulfate as an iodine scavenger is part of the first-year general chemistry laboratory curriculum at Dalhousie University. With…

  20. Nuclear Reaction Data Centers

    International Nuclear Information System (INIS)

    McLane, V.; Nordborg, C.; Lemmel, H.D.; Manokhin, V.N.

    1988-01-01

    The cooperating Nuclear Reaction Data Centers are involved in the compilation and exchange of nuclear reaction data for incident neutrons, charged particles and photons. Individual centers may also have services in other areas, e.g., evaluated data, nuclear structure and decay data, reactor physics, nuclear safety; some of this information may also be exchanged between interested centers. 20 refs., 1 tab

  1. Hydrogen evolution reaction catalyst

    Science.gov (United States)

    Subbaraman, Ram; Stamenkovic, Vojislav; Markovic, Nenad; Tripkovic, Dusan

    2016-02-09

    Systems and methods for a hydrogen evolution reaction catalyst are provided. Electrode material includes a plurality of clusters. The electrode exhibits bifunctionality with respect to the hydrogen evolution reaction. The electrode with clusters exhibits improved performance with respect to the intrinsic material of the electrode absent the clusters.

  2. Applications of Reaction Rate

    Science.gov (United States)

    Cunningham, Kevin

    2007-01-01

    This article presents an assignment in which students are to research and report on a chemical reaction whose increased or decreased rate is of practical importance. Specifically, students are asked to represent the reaction they have chosen with an acceptable chemical equation, identify a factor that influences its rate and explain how and why it…

  3. Degradations and Rearrangement Reactions

    Science.gov (United States)

    Zhang, Jianbo

    This section deals with recent reports concerning degradation and rearrangement reactions of free sugars as well as some glycosides. The transformations are classified in chemical and enzymatic ways. In addition, the Maillard reaction will be discussed as an example of degradation and rearrangement transformation and its application in current research in the fields of chemistry and biology.

  4. Allergic reactions during anesthesia.

    Science.gov (United States)

    Levy, J H

    1988-01-01

    Any drug or blood product administered in the perioperative period has the potential to produce a life-threatening allergic (immune reaction) called anaphylaxis. Anaphylactic reactions represent adverse reactions mediated by immunospecific antibodies (IgE and IgG) that interact with mast cells, basophils, or the complement system to liberate vasoactive mediators and recruit other inflammatory cells. Activation of humoral and cellular pathways produces characteristic responses in the respiratory (bronchospasm and upper airway edema), cardiovascular (vasodilation and increased capillary permeability), and cutaneous systems (wheal and flare). Other predictable adverse drug reactions may mimic anaphylaxis to produce similar physiologic consequences independent of allergy (immune responses). Rapid and timely cardiopulmonary intervention with airway maintenance, epinephrine, and volume expansion is essential to avoid an adverse outcome. Severe reactions may be protracted, especially during anesthesia, requiring even larger doses of catecholamines and intensive care observation.

  5. Enhancing chemical reactions

    Science.gov (United States)

    Morrey, John R.

    1978-01-01

    Methods of enhancing selected chemical reactions. The population of a selected high vibrational energy state of a reactant molecule is increased substantially above its population at thermal equilibrium by directing onto the molecule a beam of radiant energy from a laser having a combination of frequency and intensity selected to pump the selected energy state, and the reaction is carried out with the temperature, pressure, and concentrations of reactants maintained at a combination of values selected to optimize the reaction in preference to thermal degradation by transforming the absorbed energy into translational motion. The reaction temperature is selected to optimize the reaction. Typically a laser and a frequency doubler emit radiant energy at frequencies of .nu. and 2.nu. into an optical dye within an optical cavity capable of being tuned to a wanted frequency .delta. or a parametric oscillator comprising a non-centrosymmetric crystal having two indices of refraction, to emit radiant energy at the frequencies of .nu., 2.nu., and .delta. (and, with a parametric oscillator, also at 2.nu.-.delta.). Each unwanted frequency is filtered out, and each desired frequency is focused to the desired radiation flux within a reaction chamber and is reflected repeatedly through the chamber while reactants are fed into the chamber and reaction products are removed therefrom.

  6. Respiratory transfusion reactions

    Directory of Open Access Journals (Sweden)

    Ivica Marić

    2017-11-01

    Full Text Available Respiratory transfusion-related reactions are not very frequent, partly also because recognition and reporting transfusion reactions is still underemphasized. Tis article describes the most important respiratory transfusion reactions, their pathophysiology, clinical picture and treatment strategies. Respiratory transfusion related reactions can be primary or secondary. The most important primary transfusion-related reactions are TRALI - transfusion-related acute lung injury, TACO – transfusion-associated circulatory overload, and TAD - transfusion-associated dyspnea. TRALI is immuneassociated injury of alveolar basal membrane, which becomes highly permeable and causes noncardiogenic pulmonary edema. Treatment of TRALI is mainly supportive with oxygen, fluids (in case of hypotension and in cases of severe acute respiratory failure also mechanic ventilation. TACO is caused by volume overload in predisposed individuals, such as patients with heart failure, the elderly, infants, patients with anemia and patients with positive fluid balance. Clinical picture is that of a typical pulmonary cardiogenic edema, and the therapy is classical: oxygen and diuretics, and in severe cases also non-invasive or invasive mechanical ventilation. TAD is usually a mild reaction of unknown cause and cannot be classified as TACO or TRALI, nor can it be ascribed to patient’s preexisting diseases. Although the transfusion-related reactions are not very common, knowledge about them can prevent serious consequences. On the one hand preventive measures should be sought, and on the other early recognition is beneficial, so that proper treatment can take place.

  7. Environmental protection directory. 3. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Schumacher, H.G.

    1993-01-01

    For the first time in this form in Germany, this handbook provides a comprehensive collection of mainly non-commercial environmental protection addresses. It covers the federal, community, scientific and jounalistic areas as well as business and society associations and groups, educational and advisory services and institutions. The addressbook contains the addresses and telephone numbers of the seperate institutions, as well as the names and extension numbers of public officials, representatives and media relations personned of the associations, the party environmental spokesperson and assigned people from the churches, and the ecology editors in media, radio and television. (orig.) [de

  8. EEG. Renewables Act. Comment. 4. new rev. and enl. ed.

    International Nuclear Information System (INIS)

    Frenz, Walter; Cosack, Tilman

    2015-01-01

    Unlike any other Act, the Renewable Energy Sources Act (EEG) changes continuously. Recently it has been fundamentally transformed with the amendment 2014. Comprehensive, readable and practice-oriented. The proven Berliner comment EEG is your reliable companion through the new regulatory regime. All provisions of the EEG 2014 thorough and easy to understand commented by experts of the matter. 2. The EEG Amending Act of 29.6.2015 has already been considered. A detailed introduction and contributions to the relevant European law and the antitrust aspects of the renewable energy sources to guarantee you a broad understanding of the rules. Valuable background information you provide, the digressions of the most important renewable energy technologies, will explain the pictures thanks to numerous the scientific and technical foundations. Moreover you the construction law aspects in the construction of photovoltaic and wind turbines are explained clearly. [de

  9. The effects of nuclear war. 2. rev. enl. ed.

    International Nuclear Information System (INIS)

    Rodejohann, J.

    1982-01-01

    Possible and probable effects of a nuclear war in Europe are described on the basis of a study by the Office of Technology Assessment, US Kongress ('The effects of nuclear war', Wash. D.C. 1979). (HP) [de

  10. Course on radiology and radiation protection. 3. rev. enl. ed.

    International Nuclear Information System (INIS)

    1981-01-01

    This book shall serve as accompanying study text-book for students of medicine, who are in the clinical semesters in the course on radiology and radiation protection. The book deals in general with the field of radiology, starting from the physical and radiobiological fundamentals, through the large field of X-ray diagnostics and radiotherapy to nuclear medicine, including computerized tomography. Broad space is dedicated to radiation protection. A brief, strongly didactically divided text presents this large scientific field of knowledge in systematic order. It is illustrated by numerous tables and sketches, which shall facilitate understanding in cases of difficult problems. The book is completed by a detailed time table, by references to the essential and most important advancing literature and by a comprehensive subject index. (orig./HP) [de

  11. Radioactive waste - wherever to remove? 2. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Stierstadt, Klaus; Fischer, Guenther

    2011-01-01

    The book presents an overview on th actual global situation, but concentrates mainly on Germany. The reader gets to know how dangerous is radioactive waste, how the removal problem is solved reliably, why still today this have not been happened, and wether we need nuclear energy for a long time. The data and facts enable the reader to judge advantages and disadvantages of nuclear energy and discuss about it competently.(orig./GL) [de

  12. Quantum mechanics. Introduction. 6. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Greiner, W.

    2005-01-01

    The following topics are dealt with: Quantization of physical quantities, radiation laws, the wave aspect of matter, mathematical foundations of quantum mechanics, ther Schroedinger equation, the harmonic oscillator, the transition from classical to quantum mechanics, a charged particle in the electromagnetic field, the hydrogen atom, perturbation theory and approximation procedures, spin, a nonrelativistic wave equation with spin, systems of identical particles, the formal scheme of quantum mechanics, conceptions and philosophical problems of quantum mechanics. (HSI)

  13. Quantum physics. 9. tot. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Gasiorowicz, S.

    2005-01-01

    This textbook belongs to the mostly favorite and illustrative introductions to quantum physics. The understandable way of presentation allows the independent access of the physical background of the world of quanta. Starting from the physical phenomena the book mediates the fundamental terms and procedures of quantum mechanics and illustrates them by means of extensive application examples and estimations of orders of magnitude. This proximity tro praxis gives to the book its aliveness. For the better understanding Gasiorowicz includes explaining steps and abandons complicated mathematical derivations. The discussion of the physical connections helps in the illustration of formal calculations. By this the successful transition from a course about modern physics to the purely formal development of quantum mechanics is possible. Numerous exercises are found in the extended part of problems. Furthermore the commented list of literature in the appendix is a valuable orientational aid for the study of quantum physics. The 9th edition was completely surveyed, actualized, and extended

  14. Neurology check list. 5. rev. and enl. ed.; Checkliste Neurologie

    Energy Technology Data Exchange (ETDEWEB)

    Grehl, Holger [Evangelisches und Johanniter Klinikum, Duisburg (Germany). Neurologische Klinik; Reinhardt, Frank

    2013-02-01

    The neurology check list covers the following issues, organized in four parts: Grey part - diagnostic fundamentals, therapeutic principles: clinical neurological examination, liquor puncture, specific laboratory diagnostics, neurophysical diagnostics, imaging techniques, therapeutic principles, legal aspects, neurological assessment. Green Part - leading syndromes and leading symptoms. Blue part - neurological disease appearance: pains in head and face, pain syndrome, congenital and development disturbances, liquor circulation disturbances, ZNS hemorrhages, tumors and neoplasm, paraneoplastic syndromes, inflammatory diseases of the nervous system, dementia diseases, metabolic and other encephalopathy, cerebellum diseases and system surmounting processes, movement degeneration, basal ganglion diseases, epilepsy, non-epileptic attacks, medulla diseases, brain nerve diseases, plexus lesions, radicular lesions, peripheric neuropathy, neuromuscular transfer disturbances, muscular diseases. Red part: neurological intensive medicine.

  15. Diagnostic imaging of the hand. 3. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Schmitt, Rainer; Lanz, Ulrich

    2015-01-01

    The book on diagnostic imaging of the hand covers the following issues: projection radiography, cinematography, MRT and CR arthrography, arthroscopy, arteriography, skeleton scintiscanning, sonography, computerized tomography, magnetic resonance tomography, anatomy of forearm and carpus, anatomy of metacarpus and fingers, carpal function and morphometry, postoperative X-ray diagnostic, growing hand skeleton, normative variants, malformations and deformities, trauma of the distal forearm, lesions of the ulnocarpal complex (TFCC), scaphoid fractures, scaphoid arthrosis, fractures of other carpus bones, carpal luxations and luxation fractures, carpal instabilities, fractures of the metacarpalla, finger fractures, arthrosis deformans, enthesiopathies, sport induced soft tissue lesions, osteonecrosis, impingement syndromes, osteopenic skeletal diseases, metabolis diseases, crystal-induced osteoarthropaties, rheumatoid arthritis, spondyloarthritis, rheumatic fever, collagenoses, infective arthritis, osteomyelitis, soft tissue infections, cystoids bone lesions, skeletal tumors, soft tissue tumors, carpal tunnel syndrome, nerve compression syndrome, arterial perfusion disturbances, differential diagnostic tables on hand lesions.

  16. Angiography. 2. tot. rev. and enl. ed.; Angiographie

    Energy Technology Data Exchange (ETDEWEB)

    Schild, H. (ed.); Born, M.; Eckert, B.; Hofer, U.; Kaltenborn, H.; Kersjes, W.; Malms, J.; Remig, J.; Schunk, K.; Strunk, H.; Urbach, H.; Wilhelm, K.

    2003-07-01

    New features of the second German edition of this standard textbook: a novel, attractive layout supporting the didactic concept, including highlighted important information and compact summaries. - Comparative evaluation with other methods, such as color Doppler sonography and MR angiography. - Comprehensive revision of images and addition of new pictures. (orig./CB) [German] Neu in der 2. Auflage: neues, ansprechendes Layout fuer noch mehr Didaktik und ''Spass am Lernen'' durch Merksaetze und Zusammenfassungen. - Vergleich mit anderen Verfahren wie Farbdoppler-Sonographie und MR-Angiographie. - Umfassende Ueberarbeitung und Erweiterung des Bildmaterials. (orig./AJ)

  17. Stable isotope geochemistry. 3. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Hoefs, J.

    1987-01-01

    Stable Isotope Geochemistry is an authoritative book comprising theoretical and experimental principles; surveying important fractionation mechanisms affecting the most important elements; discussing the natural variations of geologically important reservoirs. This updated 3rd edition, with a completely rewritten and extended main part, contains two new chapters on stable isotope composition of mantle material and on changes of the ocean during the geological past. (orig.)

  18. Wind energy utilisation. 7. enl. and compl. rev. ed.

    International Nuclear Information System (INIS)

    Heier, Siegfried

    2016-01-01

    The use of wind energy register furthermore rapid technological advances. Intensive research efforts in scientific institutions and in industry have led to it that the plants are reliable high technology products today. An overview of these developments give the completely revised BINE reference-book. The focus is on technologies, concepts and the market development of the wind industry. Other topics include network integration, economy and current research perspectives as well as environmental balance and repowering. Planners, investors and students get an overview of the status and development of the technology, the economy and the legal framework. [de

  19. Neuroradiology. 2. tot. rev. and enl. ed.; Neuroradiologie

    Energy Technology Data Exchange (ETDEWEB)

    Sartor, K. (ed.)

    2001-07-01

    This second, totally revised and enlarged German edition of the toolbook in the ''RRR'' series of Thieme Verlag features: Enhanced coverage of MRI techniques. - Emphasis on clinical findings. - Compact summaries of the current specialist knowledge placed at the end of each chapter. - Major portion of illustrations replaced by new images reflecting the state of the art. (orig./CB) [German] Das bewaehrte Darstellungskonzept wurde in der Neuauflage beibehalten und inhaltlich ergaenzt: Noch staerkere Einbeziehung der MRT. - Konzentration auf den klinischen Befund. - Das Facharztwissen ''Neuroradiologie'' am Kapitelende zusammengefasst. - Grossenteils komplett neue Abbildungen. (orig./AJ)

  20. MRT of the locomotor system. 4. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Vahlensieck, Martin; Reiser, Maximilian

    2015-01-01

    The book on MRT of the locomotor system covers the following topics: relevant NMT imaging techniques, spinal cord, shoulder, elbows, wrist and fingers, hip region, knee, lower leg - ankle - foot, temporomandibular joint, skeletal muscles, bone marrow, bone and soft tissue tumors, osteoporosis, sacroiliac joint, jaw and periodontium.

  1. Radiology of haemophilic arthropathies. 2. rev., enl. ed.

    International Nuclear Information System (INIS)

    Forrai, J.

    1979-01-01

    Radiology plays an important role in confirming the diagnosis of haemophilia, in solving differential diagnostic problems, in the indication of surgical intervention and in the care of haemophiliacs. A detailed and accurate description of the X-ray symptomatology is given in this monograph. The author tries to fit the single radiomorphological signs into the entire, long pathological process. (Auth.)

  2. Albert Einstein for beginners. 12. enl. and rev. ed.

    International Nuclear Information System (INIS)

    Karamanolis, Stratis

    2008-01-01

    He was called the most important jew since the birth of Christus. Others however believed however he has came like no other nearer to the gods. Thought is Albrt Einstein, the scientific work of him and especially his relativity theory has the world changed radically both in scientific and in political regard. The present 12th extended and strongly revised edition of the book, which came out firstly above 20 years ago and until today thousands of readers - young and old - has always enthused, describes not only the relativity theory but also the role, which Einstein played in the development of the first atomic bomb. A short biographical part mediates to the reader also something about the man Einstein

  3. Neurology check list. 5. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Grehl, Holger; Reinhardt, Frank

    2013-01-01

    The neurology check list covers the following issues, organized in four parts: Grey part - diagnostic fundamentals, therapeutic principles: clinical neurological examination, liquor puncture, specific laboratory diagnostics, neurophysical diagnostics, imaging techniques, therapeutic principles, legal aspects, neurological assessment. Green Part - leading syndromes and leading symptoms. Blue part - neurological disease appearance: pains in head and face, pain syndrome, congenital and development disturbances, liquor circulation disturbances, ZNS hemorrhages, tumors and neoplasm, paraneoplastic syndromes, inflammatory diseases of the nervous system, dementia diseases, metabolic and other encephalopathy, cerebellum diseases and system surmounting processes, movement degeneration, basal ganglion diseases, epilepsy, non-epileptic attacks, medulla diseases, brain nerve diseases, plexus lesions, radicular lesions, peripheric neuropathy, neuromuscular transfer disturbances, muscular diseases. Red part: neurological intensive medicine.

  4. Environmental protection technology. 4. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Foerstner, U.

    1993-01-01

    The book deals on a broad basis with subjects related to environmental pollution. Both ecological and economic aspects are covered; technical means of avoiding and remedying environmental damage are discussed. Included are also an ethical evaluation and the legal aspects of the environmental pollution problem. (UT). 120 figs [de

  5. Nuclear medicine. 4. new rev. and enl. ed.; Nuklearmedizin

    Energy Technology Data Exchange (ETDEWEB)

    Kuwert, T. [Universitaetsklinikum Erlangen (Germany). Nuklearmedizinische Klinik; Gruenwald, F. [Klinikum der Johann-Wolfgang-Goethe-Univ., Frankfurt (Germany). Klinik fuer Nuklearmedizin; Haberkorn, U. [Universitaetsklinikum Heidelberg (Germany). Abt. Nuklearmedizin; Krause, T. (eds.) [Universitaetsklinik Bern (Switzerland). Dept. Radiologie, Neuroradiologie und Nuklearmedizin

    2008-07-01

    The book on nuclear medicine is devided in three chapters: fundamentals, diagnostics and therapy. The topics within these chapters are the following: 1) fundamentals: molecular imaging; radiation physics, measuring technology and quality control; dosimetry and radiation effects; radiation protection, radiopharmaceutical chemistry; immonoassays and quality control. 2) diagnostics: endocrine organs; oncology; heart, vascular system and blood vessels; brain, lungs, skelton, kidneys, gastrointestine tract; infections; hematology. 3) radiotherapy; radiosynoviorothese; palliative bone pain therapy; radioimmunotherapy; {sup 1}31I-MIBG therapy; therapy with receptor affine peptides; specific nuclear medical therapies.

  6. Introduction to Elementary particles. 2. enl. and rev. ed.

    International Nuclear Information System (INIS)

    Griffiths, D.

    2008-01-01

    In the second, revised edition of a well-established textbook, the author strikes a balance between quantitative rigor and intuitive understanding, using a lively, informal style. The first chapter provides a detailed historical introduction to the subject, while subsequent chapters offer a quantitative presentation of the Standard Model. A simplified introduction to the Feynman rules, based on a ''toy'' model, helps readers learn the calculational techniques without the complications of spin. It is followed by accessible treatments of quantum electrodynamics, the strong and weak interactions, and gauge theories. New chapters address neutrino oscillations and prospects for physics beyond the Standard Model. The book contains a number of worked examples and many end-of-chapter problems. A complete solution manual is available for instructors. - revised edition of well-established text on elementary particle physics; - with a number of worked examples and many end-of-chapter problems; - helps the student to master the Feynman rules; - solution manual available for instructors. (orig.)

  7. The Reaction Wheel Pendulum

    CERN Document Server

    Block, Daniel J; Spong, Mark W

    2007-01-01

    This monograph describes the Reaction Wheel Pendulum, the newest inverted-pendulum-like device for control education and research. We discuss the history and background of the reaction wheel pendulum and other similar experimental devices. We develop mathematical models of the reaction wheel pendulum in depth, including linear and nonlinear models, and models of the sensors and actuators that are used for feedback control. We treat various aspects of the control problem, from linear control of themotor, to stabilization of the pendulum about an equilibrium configuration using linear control, t

  8. Electron transfer reactions

    CERN Document Server

    Cannon, R D

    2013-01-01

    Electron Transfer Reactions deals with the mechanisms of electron transfer reactions between metal ions in solution, as well as the electron exchange between atoms or molecules in either the gaseous or solid state. The book is divided into three parts. Part 1 covers the electron transfer between atoms and molecules in the gas state. Part 2 tackles the reaction paths of oxidation states and binuclear intermediates, as well as the mechanisms of electron transfer. Part 3 discusses the theories and models of the electron transfer process; theories and experiments involving bridged electron transfe

  9. Reactor for exothermic reactions

    Science.gov (United States)

    Smith, L.A. Jr.; Hearn, D.; Jones, E.M. Jr.

    1993-03-02

    A liquid phase process is described for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F. Wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

  10. Bad Reaction to Cosmetics?

    Science.gov (United States)

    ... Consumers Protect Yourself Health Fraud Bad Reactions to Cosmetics? Tell FDA! Share Tweet Linkedin Pin it More ... Radiation-Emitting Products Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products

  11. Transfusion reaction - hemolytic

    Science.gov (United States)

    ... Names Blood transfusion reaction Images Surface proteins causing rejection References Choate JD, Maitta RW, Tormey CA, Wu ... PA: Elsevier Saunders; 2016:chap 177. Hall JE. Blood types; transfusion; tissue and organ transplantation. In: Hall JE, ...

  12. Reaction Qualifications Revisited

    DEFF Research Database (Denmark)

    Lippert-Rasmussen, Kasper

    2009-01-01

    to a person's effectiveness by causing a favourable reaction in customers, co-workers etc. (for short: recipients) - are involved, this assumption is false. Building on work by Wertheimer, Mason, and Miller, this paper proposes an account of the reaction qualifications that count, from the point of view...... preferences, recipients should not respond to the applicant actually hired on the basis of their (the recipients') racial preferences. My account decomposes the meritocratic ideal into four separate norms, one of which applies to recipients rather than to selectors. Finally, it defends the view that reaction...... qualifications based on antimeritocratic reactions, while not unproblematic, are not entirely irrelevant from the point of view of merit. Notably, selectors need not discount them when no one - including the targets of the objectionable preferences - is unfairly disadvantaged. Because not all problematic...

  13. Sequential charged particle reaction

    International Nuclear Information System (INIS)

    Hori, Jun-ichi; Ochiai, Kentaro; Sato, Satoshi; Yamauchi, Michinori; Nishitani, Takeo

    2004-01-01

    The effective cross sections for producing the sequential reaction products in F82H, pure vanadium and LiF with respect to the 14.9-MeV neutron were obtained and compared with the estimation ones. Since the sequential reactions depend on the secondary charged particles behavior, the effective cross sections are corresponding to the target nuclei and the material composition. The effective cross sections were also estimated by using the EAF-libraries and compared with the experimental ones. There were large discrepancies between estimated and experimental values. Additionally, we showed the contribution of the sequential reaction on the induced activity and dose rate in the boundary region with water. From the present study, it has been clarified that the sequential reactions are of great importance to evaluate the dose rates around the surface of cooling pipe and the activated corrosion products. (author)

  14. Firefighter Nozzle Reaction

    DEFF Research Database (Denmark)

    Chin, Selena K.; Sunderland, Peter B.; Jomaas, Grunde

    2017-01-01

    to anchor forces, the hose becomes straight. The nozzle reaction is found to equal the jet momentum flow rate, and it does not change when an elbow connects the hose to the nozzle. A forward force must be exerted by a firefighter or another anchor that matches the forward force that the jet would exert...... on a perpendicular wall. Three reaction expressions are derived, allowing it to be determined in terms of hose diameter, jet diameter, flow rate, and static pressure upstream of the nozzle. The nozzle reaction predictions used by the fire service are 56% to 90% of those obtained here for typical firefighting hand......Nozzle reaction and hose tension are analyzed using conservation of fluid momentum and assuming steady, inviscid flow and a flexible hose in frictionless contact with the ground. An expression that is independent of the bend angle is derived for the hose tension. If this tension is exceeded owing...

  15. Nucleon induced reactions

    International Nuclear Information System (INIS)

    Gmuca, S.; Antalik, R.; Kristiak, J.

    1988-01-01

    The collection contains full texts of 37 contributions; all fall within the INIS Subject Scope. The topics treated include some unsolved problems of nuclear reactions and relevant problems of nuclear structure at low and intermediate energies. (Z.S.)

  16. Jets in hadronic reactions

    Energy Technology Data Exchange (ETDEWEB)

    Paige, F.E.

    1983-01-01

    Recent experimental data on the properties of jets in hadronic reactions are reviewed and compared with theoretical expectations. Jets are clearly established as the dominant process for high E/sub T/ events in hadronic reactions. The cross section and the other properties of these events are in qualitative and even semiquantitative agreement with expectations based on perturbative QCD. However, we can not yet make precise tests of QCD, primarily because there are substantial uncertainties in the theoretical calculations. 45 references. (WHK)

  17. Oxygen evolution reaction catalysis

    Science.gov (United States)

    Haber, Joel A.; Jin, Jian; Xiang, Chengxiang; Gregoire, John M.; Jones, Ryan J.; Guevarra, Dan W.; Shinde, Aniketa A.

    2016-09-06

    An Oxygen Evolution Reaction (OER) catalyst includes a metal oxide that includes oxygen, cerium, and one or more second metals. In some instances, the cerium is 10 to 80 molar % of the metals in the metal oxide and/or the catalyst includes two or more second metals. The OER catalyst can be included in or on an electrode. The electrode can be arranged in an oxygen evolution system such that the Oxygen Evolution Reaction occurs at the electrode.

  18. Anaphylactic reaction to orthoiodohippurate

    Energy Technology Data Exchange (ETDEWEB)

    Stoeckel, M.; Roedbro, P.; Ennow, K.; Kristensen, K.

    1983-02-01

    A case of an anaphylactic reaction following administration of /sup 125/I- and /sup 131/-I-o-iodohippurate in a 32-year-old woman is reported. The patient had a renography performed because of hematuria. She was known to react to an intravenous pyelography previously performed with an anaphylactic shock. The importance of reporting all adverse reactions to radiopharmaceuticals for central registration is stressed.

  19. Adverse drug reactions.

    Science.gov (United States)

    Patton, K; Borshoff, D C

    2018-01-01

    Adverse drug reactions are a cause of significant morbidity and mortality to patients and a source of financial burden to the healthcare system. Of the wide spectrum of adverse drug reactions, the most concerning to the anaesthetist remain anaphylaxis and malignant hyperthermia. Although the incidence of anaphylaxis under anaesthesia is difficult to ascertain, it occurs commonly enough that most anaesthetists will manage at least one case in their career. The wide range of drugs given in the peri-operative period and the variable presentation in the anaesthetised patient can delay diagnosis and treatment, and adversely affect outcome. Furthermore, despite improvements in testing, causative drugs can still be difficult to identify, as adverse reactions may be mediated by mechanisms other than IgE activation. With an increase in the reporting of anaphylaxis to newer anaesthetic drugs such as sugammadex, combined with change over the recent decades in the most likely causative peri-operative agents, it is imperative anaesthetists remain up to date on recent developments. In addition, they should be vigilant to patient characteristics, including pharmacogenetic variations that may predispose to adverse drug reactions, in order to help minimise risks of a reaction. The severity of adverse drug reactions to peri-operative drugs means morbidity and mortality remain high. © 2018 The Association of Anaesthetists of Great Britain and Ireland.

  20. Immediate reaction to clarithromycin.

    Science.gov (United States)

    Gangemi, S; Ricciardi, L; Fedele, R; Isola, S; Purello-D'Ambrosio, F

    2001-01-01

    We present the case of bronchospastic reaction to clarithromycin had during a drug challenge test. Personal allergic history was negative for respiratory allergies and positive for adverse drug reactions to general and regional anesthesia and to ceftriaxone. After the administration of 1/4 of therapeutic dose of clarithromycin the patient showed dyspnea, cough and bronchospasm in all the lung fields. The positivity of the test was confirmed by the negativity to the administration of placebo. The quickness and the clinical characteristic of the adverse reaction suggest a pathogenic mechanism of immediate-type hypersensitivity. On reviewing the literature we have found no reports of bronchospastic reaction to clarithromycin. Macrolides are a class of antibiotics mainly used in the last years in place of beta-lactams because of a broad spectrum of action and a low allergic power. In fact, there are few reports on allergic reactions to these molecules. Clarithromycin is one of the latest macrolides, characterised by the presence of a 14-carbon-atom lactone ring as erythromycin, active on a wide spectrum of pathogens.

  1. Chemical kinetics of gas reactions

    CERN Document Server

    Kondrat'Ev, V N

    2013-01-01

    Chemical Kinetics of Gas Reactions explores the advances in gas kinetics and thermal, photochemical, electrical discharge, and radiation chemical reactions. This book is composed of 10 chapters, and begins with the presentation of general kinetic rules for simple and complex chemical reactions. The next chapters deal with the experimental methods for evaluating chemical reaction mechanisms and some theories of elementary chemical processes. These topics are followed by discussions on certain class of chemical reactions, including unimolecular, bimolecular, and termolecular reactions. The rema

  2. Inflammatory reaction in chondroblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Yamamura, Sigeki [Dept. of Orthopedic Surgery, Nagoya Univ. School of Medicine (Japan); Sato, Keiji [Dept. of Orthopedic Surgery, Nagoya Univ. School of Medicine (Japan); Sugiura, Hideshi [Dept. of Orthopedic Surgery, Nagoya Univ. School of Medicine (Japan); Iwata, Hisashi [Dept. of Orthopedic Surgery, Nagoya Univ. School of Medicine (Japan)

    1996-05-01

    The objective of this study was to evaluate the inflammatory reaction accompanying chondroblastoma and to define the value of the finding in clinical practice. We reviewed the clinical, radiographic, and magnetic resonance (MR) findings in six patients with histologically proven chondroblastoma. In all cases, MR imaging showered marrow and soft tissue edema. In four of six cases, periosteal reaction related to intra-osseous edema was more clearly demonstrated on MR imaging than on radiographs. Follow-up MR studies after surgery were available in three patients and all showed disappearance of inflammatory responses such as marrow and soft tissue edema, and reactive synovitis. We propose that these inflammatory reactions of chondroblastomas are inportant signs for detecting residual tumor in recurrences after surgery, as well as for making a precise diagnosis. The MR changes may also be valuable in demonstrating eradication of the tumor. (orig./MG)

  3. Nanoparticle Reactions on Chip

    Science.gov (United States)

    Köhler, J. M.; Kirner, Th.; Wagner, J.; Csáki, A.; Möller, R.; Fritzsche, W.

    The handling of heterogenous systems in micro reactors is difficult due to their adhesion and transport behaviour. Therefore, the formation of precipitates and gas bubbles has to be avoided in micro reaction technology, in most cases. But, micro channels and other micro reactors offer interesting possibilities for the control of reaction conditions and transport by diffusion and convection due to the laminar flow caused by small Reynolds numbers. This can be used for the preparation and modification of objects, which are much smaller than the cross section of microchannels. The formation of colloidal solutions and the change of surface states of nano particles are two important tasks for the application of chip reactors in nanoparticle technology. Some concepts for the preparation and reaction of nanoparticles in modular chip reactor arrangements will be discussed.

  4. Velocity pump reaction turbine

    Science.gov (United States)

    House, P.A.

    An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

  5. Reactions to dietary tartrazine.

    OpenAIRE

    David, T J

    1987-01-01

    Double blind challenges with tartrazine and benzoic acid were performed in hospital in 24 children whose parents gave a definite history of a purely behavioural immediate adverse reaction to one of these substances. The patients, whose ages ranged from 1.6 to 12.4 years, were on a diet that avoided these items, and in all there was a clear history that any lapse of the diet caused an obvious adverse behavioural reaction within two hours. In no patient was any change in behaviour noted either ...

  6. Allergic reactions in anaesthesia

    DEFF Research Database (Denmark)

    Krøigaard, M; Garvey, L H; Menné, T

    2005-01-01

    match, the right substance being suspected, but investigations showed an additional allergen or several substances, including the right substance being suspected. CONCLUSIONS: An informed guess is not a reliable way of determining the cause of a supposed allergic reaction during anaesthesia and may put...... a significant number of patients at unnecessary risk. Some patients may be labelled with a wrong allergy, leading to unnecessary warnings against harmless substances, and some patients may be put at risk of subsequent re-exposure to the real allergen. Patients with suspected allergic reactions during...

  7. Introduction to nuclear reactions

    International Nuclear Information System (INIS)

    Satchler, G.R.

    1980-01-01

    This introduction to nuclear reaction phenomena is aimed primarily but not exclusively at readers at the undergraduate student level. An overview of the subject is presented in the first two chapters entitled - Some background information and Introduction to nuclear reactions. The third chapter reviews scattering theory with emphasis on the underlying physical ideas and also provides schematic entrees to the more advanced topics. The physical models which have been developed to account for the various aspects of nuclear phenomena are described in more detail in chapter 4. References and exercises are appended to each chapter. (U.K.)

  8. Modeling of Reaction Calorimeter

    OpenAIRE

    Farzad, Reza

    2014-01-01

    The purpose of this project was to model the reaction calorimeter in order to calculate the heat of absorption which is the most important parameter in this work. Reaction calorimeter is an apparatus which is used in measuring the heat of absorption of CO2 as well as the total pressure in vapor phase based on vapor-liquid equilibrium state. Mixture of monoethanolamine (MEA) and water was used as a solvent to absorb the CO2.Project was divided in to three parts in order to make the programming...

  9. Anniversary reactions in therapists.

    Science.gov (United States)

    Granet, R B; Kalman, T P

    1982-12-01

    The authors provide three case examples of anniversary reactions in psychotherapists evoked in the course of treating patients. They note that psychotherapy has always been discussed in terms of time and phases, which lend themselves to periodicities and may provide the potential for anniversary phenomena. The authors recommend that therapists be aware of such phenomena; monitor their own losses, defenses, and dreams; and continue their own supervision. Possible positive aspects of identification of therapists' anniversary reactions are increased empathy with patients and help in completing unresolved therapeutic and personal issues.

  10. Reaction Decoder Tool (RDT): extracting features from chemical reactions

    OpenAIRE

    Rahman, Syed Asad; Torrance, Gilliean; Baldacci, Lorenzo; Mart?nez Cuesta, Sergio; Fenninger, Franz; Gopal, Nimish; Choudhary, Saket; May, John W.; Holliday, Gemma L.; Steinbeck, Christoph; Thornton, Janet M.

    2016-01-01

    Summary: Extracting chemical features like Atom?Atom Mapping (AAM), Bond Changes (BCs) and Reaction Centres from biochemical reactions helps us understand the chemical composition of enzymatic reactions. Reaction Decoder is a robust command line tool, which performs this task with high accuracy. It supports standard chemical input/output exchange formats i.e. RXN/SMILES, computes AAM, highlights BCs and creates images of the mapped reaction. This aids in the analysis of metabolic pathways and...

  11. Reaction Formulation: A Bibliography.

    Science.gov (United States)

    Pedrini, D. T.; Pedrini, Bonnie C.

    Reaction formation was studied by Sigmund Freud. This defense mechanism may be related to repression, substitution, reversal, and compensation (or over-compensation). Alfred Adler considered compensation a basic process in his individual psychology. Anna Freud discussed some defense mechanisms, and Bibring, Dwyer, Huntington, and Valenstein…

  12. Cluster knockout reactions

    Indian Academy of Sciences (India)

    2014-04-07

    Apr 7, 2014 ... Cluster knockout reactions are expected to reveal the amount of clustering (such as that of , d and even of heavier clusters such as 12C, 16O etc.) in the target nucleus. In simple terms, incident medium high-energy nuclear projectile interacts strongly with the cluster (present in the target nucleus) as if it ...

  13. Polymerase chain reaction system

    Science.gov (United States)

    Benett, William J.; Richards, James B.; Stratton, Paul L.; Hadley, Dean R.; Milanovich, Fred P.; Belgrader, Phil; Meyer, Peter L.

    2004-03-02

    A portable polymerase chain reaction DNA amplification and detection system includes one or more chamber modules. Each module supports a duplex assay of a biological sample. Each module has two parallel interrogation ports with a linear optical system. The system is capable of being handheld.

  14. Reaction product imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chandler, D.W. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    Over the past few years the author has investigated the photochemistry of small molecules using the photofragment imaging technique. Bond energies, spectroscopy of radicals, dissociation dynamics and branching ratios are examples of information obtained by this technique. Along with extending the technique to the study of bimolecular reactions, efforts to make the technique as quantitative as possible have been the focus of the research effort. To this end, the author has measured the bond energy of the C-H bond in acetylene, branching ratios in the dissociation of HI, the energetics of CH{sub 3}Br, CD{sub 3}Br, C{sub 2}H{sub 5}Br and C{sub 2}H{sub 5}OBr dissociation, and the alignment of the CD{sub 3} fragment from CD{sub 3}I photolysis. In an effort to extend the technique to bimolecular reactions the author has studied the reaction of H with HI and the isotopic exchange reaction between H and D{sub 2}.

  15. Explaining competitive reaction effects

    NARCIS (Netherlands)

    Leeflang, P.S.H.; Wittink, D.R.

    Changes in promotional expenditure decisions for a brand, as in other marketing decisions, should be based on the expected impact on purchase and consumption behavior as well as on the likely reactions by competitors. Purchase behavior may be predicted from estimated demand functions. Competitive

  16. Cutaneous adverse drug reactions

    African Journals Online (AJOL)

    limiting but they can be the initial presentation of more serious reactions such as Stevens-Johnson and drug hypersensitivity syndromes.3 It is thus important for the clinician to distinguish between self-limiting morbilliform drug eruptions that resolve solely with the withdrawal of the offending drug and the life-threatening ...

  17. Michaelis–Arbuzov reaction

    Indian Academy of Sciences (India)

    agriculture, medicine and synthetic chemistry as cata- lysts and synthetic ... ophile with an electrophilic carbon2 have been found in many synthetic ... problems. Catalytic methods play a special role in synthetic organic chemistry for progress of the reactions in sim- ple fashion. Therefore, researchers have developed var-.

  18. Managing Your Emotional Reactions

    Science.gov (United States)

    ... this situation: Your friends have received promposals (or college acceptances, team places, etc.). But you haven't. Once you identify, ... each one. Which reaction would lead to the best outcome? We always have a ... that work out well. Learning to react well takes practice. But we all ...

  19. [Allergic reactions during anesthesia].

    Science.gov (United States)

    Escolano, F; Sierra, P

    1996-01-01

    Anaphylactic reaction during anesthesia is a constant source of concern for anesthesiologists, given that the rates of death and serious complications are high and predicting which patients will be susceptible is impossible. All substances used in the perioperative period carry a certain risk of releasing histamine and triggering an allergic reaction, though muscle relaxants are the drugs usually implicated. The incidence of serious anaphylaxis ranges between 1:4,000 and 1:23,000 anesthetic procedures, with mortality set at 3-9% and morbidity 10 times higher. Clinical signs vary from mild symptoms to anaphylactic shock and cardiac arrest. The diagnostic procedure to follow upon observing an allergic reaction is to first identify the responsible mechanism and later the responsible agent, as well as drugs that can be used safely. Prophylaxis is based mainly on recognizing predisposed patients before surgery and following recommendations and pharmacological protocols based on better understanding of the pathophysiological mechanisms that cause anaphylactic reaction and on experience in managing them.

  20. Multicomponent reactions in polymer synthesis.

    Science.gov (United States)

    Kakuchi, Ryohei

    2014-01-03

    More participants, yet efficient reactions: Multicomponent reactions (MCRs) have found application in polymer chemistry both in the synthesis of multifunctional monomers and in post-polymerization modification. Examples include the Passerini three-component reaction, the Ugi four-component reaction, and the copper-catalyzed MCR. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. What Is a Reaction Rate?

    Science.gov (United States)

    Schmitz, Guy

    2005-01-01

    The definition of reaction rate is derived and demonstrations are made for the care to be taken while using the term. Reaction rate can be in terms of a reaction property, the extent of reaction and thus it is possible to give a definition applicable in open and closed systems.

  2. Nuclear reactions in astrophysics

    International Nuclear Information System (INIS)

    Cardenas, M.

    1976-01-01

    It is revised the nuclear reactions which present an interest in astrophysics regarding the explanation of some problems such as the relative quantity of the elements, the structure and evolution of the stars. The principal object of the study is the determination of the experimental possibilities in the field of astrophysics, of an accelerator Van de Graaff's 700 KeV type. Two hundred nuclear reactions approximately, were found, and nothing or very little has been done in the intervals of energy which are of interest. Since the bombardment energies and the involved sections are low in some cases, there are real possibilities, for the largest number of stars to obtain important statistical data with the above mentioned accelerator, taking some necessary precautions. (author)

  3. Reactions to dietary tartrazine.

    Science.gov (United States)

    David, T J

    1987-02-01

    Double blind challenges with tartrazine and benzoic acid were performed in hospital in 24 children whose parents gave a definite history of a purely behavioural immediate adverse reaction to one of these substances. The patients, whose ages ranged from 1.6 to 12.4 years, were on a diet that avoided these items, and in all there was a clear history that any lapse of the diet caused an obvious adverse behavioural reaction within two hours. In no patient was any change in behaviour noted either by the parents or the nursing staff after the administration of placebo or active substances. Twenty two patients returned to a normal diet without problems, but the parents of two children insisted on continuing the diet. While popular belief has it that additives may have harmful behavioural effects, objective verification is required to prevent overdiagnosis.

  4. Adverse reactions to antidepressants

    DEFF Research Database (Denmark)

    Uher, Rudolf; Farmer, Anne; Henigsberg, Neven

    2009-01-01

    (74%), constipation (33%) and weight gain (15%) were associated with nortriptyline treatment. Diarrhoea (9%), insomnia (36%) and yawning (16%) were more common during treatment with escitalopram. Problems with urination and drowsiness predicted discontinuation of nortriptyline. Diarrhoea and decreased......Background: Adverse drug reactions are important determinants of non-adherence to antidepressant treatment, but their assessment is complicated by overlap with depressive symptoms and lack of reliable self-report measures. Aims: To evaluate a simple self-report measure and describe adverse...... comparing escitalopram and nortriptyline. Results: There was good agreement between self-report and psychiatrists' ratings. Most complaints listed as adverse reactions in people with depression were more common when they were medication-free rather than during their treatment with antidepressants. Dry mouth...

  5. Concordant Chemical Reaction Networks

    Science.gov (United States)

    Shinar, Guy; Feinberg, Martin

    2015-01-01

    We describe a large class of chemical reaction networks, those endowed with a subtle structural property called concordance. We show that the class of concordant networks coincides precisely with the class of networks which, when taken with any weakly monotonic kinetics, invariably give rise to kinetic systems that are injective — a quality that, among other things, precludes the possibility of switch-like transitions between distinct positive steady states. We also provide persistence characteristics of concordant networks, instability implications of discordance, and consequences of stronger variants of concordance. Some of our results are in the spirit of recent ones by Banaji and Craciun, but here we do not require that every species suffer a degradation reaction. This is especially important in studying biochemical networks, for which it is rare to have all species degrade. PMID:22659063

  6. Enzyme catalysed tandem reactions.

    Science.gov (United States)

    Oroz-Guinea, Isabel; García-Junceda, Eduardo

    2013-04-01

    To transfer to the laboratory, the excellent efficiency shown by enzymes in Nature, biocatalysis, had to mimic several synthetic strategies used by the living organisms. Biosynthetic pathways are examples of tandem catalysis and may be assimilated in the biocatalysis field for the use of isolated multi-enzyme systems in the homogeneous phase. The concurrent action of several enzymes that work sequentially presents extraordinary advantages from the synthetic point of view, since it permits a reversible process to become irreversible, to shift the equilibrium reaction in such a way that enantiopure compounds can be obtained from prochiral or racemic substrates, reduce or eliminate problems due to product inhibition or prevent the shortage of substrates by dilution or degradation in the bulk media, etc. In this review we want to illustrate the developments of recent studies involving in vitro multi-enzyme reactions for the synthesis of different classes of organic compounds. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Reactions to dietary tartrazine.

    Science.gov (United States)

    David, T J

    1987-01-01

    Double blind challenges with tartrazine and benzoic acid were performed in hospital in 24 children whose parents gave a definite history of a purely behavioural immediate adverse reaction to one of these substances. The patients, whose ages ranged from 1.6 to 12.4 years, were on a diet that avoided these items, and in all there was a clear history that any lapse of the diet caused an obvious adverse behavioural reaction within two hours. In no patient was any change in behaviour noted either by the parents or the nursing staff after the administration of placebo or active substances. Twenty two patients returned to a normal diet without problems, but the parents of two children insisted on continuing the diet. While popular belief has it that additives may have harmful behavioural effects, objective verification is required to prevent overdiagnosis. PMID:3548601

  8. Cluster knockout reactions

    Indian Academy of Sciences (India)

    2014-04-07

    Apr 7, 2014 ... (figure 2), the corresponding α–α t-matrix effective interactions are seen to be widely different (figure 3). 2. Formalism. The finite-range transition matrix element T n,l. BA in the triple differential cross-section [13], d3σ d 1d 2dE1. = Fkin × Sl × |T n,l. BA (kf 1, kf 2, ki)|2 for the (α, 2α) cluster knockout reactions is ...

  9. Flora rapid reaction forces

    Directory of Open Access Journals (Sweden)

    Виктор Васильевич Туганаев

    2015-10-01

    Full Text Available Flora rapid reaction forces ­– there are explerents that have high productivity and weak competitiveness. Their innately functional allocation is to plant disturbed acres as soon as possible preventing by that biosphere homeostasis disturbance. Disturbed acres were used to take place in geological history. Nowadays they take especially big areas. Considering a historical line of Dactylis glomerata L. authors suggest to separate out an especial group of anthropochores which they call medieophytes

  10. Photochemical reaction dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Moore, B.C. [Lawrence Berkeley Laboratory, Livermore, CA (United States)

    1993-12-01

    The purpose of the program is to develop a fundamental understanding of unimolecular and bimolecular reaction dynamics with application in combustion and energy systems. The energy dependence in ketene isomerization, ketene dissociation dynamics, and carbonyl substitution on organometallic rhodium complexes in liquid xenon have been studied. Future studies concerning unimolecular processes in ketene as well as energy transfer and kinetic studies of methylene radicals are discussed.

  11. Adverse cutaneous drug reaction

    Directory of Open Access Journals (Sweden)

    Nayak Surajit

    2008-01-01

    Full Text Available In everyday clinical practice, almost all physicians come across many instances of suspected adverse cutaneous drug reactions (ACDR in different forms. Although such cutaneous reactions are common, comprehensive information regarding their incidence, severity and ultimate health effects are often not available as many cases go unreported. It is also a fact that in the present world, almost everyday a new drug enters market; therefore, a chance of a new drug reaction manifesting somewhere in some form in any corner of world is unknown or unreported. Although many a times, presentation is too trivial and benign, the early identification of the condition and identifying the culprit drug and omit it at earliest holds the keystone in management and prevention of a more severe drug rash. Therefore, not only the dermatologists, but all practicing physicians should be familiar with these conditions to diagnose them early and to be prepared to handle them adequately. However, we all know it is most challenging and practically difficult when patient is on multiple medicines because of myriad clinical symptoms, poorly understood multiple mechanisms of drug-host interaction, relative paucity of laboratory testing that is available for any definitive and confirmatory drug-specific testing. Therefore, in practice, the diagnosis of ACDR is purely based on clinical judgment. In this discussion, we will be primarily focusing on pathomechanism and approach to reach a diagnosis, which is the vital pillar to manage any case of ACDR.

  12. Modelling Tethered Enzymatic Reactions

    Science.gov (United States)

    Solis Salas, Citlali; Goyette, Jesse; Coker-Gordon, Nicola; Bridge, Marcus; Isaacson, Samuel; Allard, Jun; Maini, Philip; Dushek, Omer

    Enzymatic reactions are key to cell functioning, and whilst much work has been done in protein interaction in cases where diffusion is possible, interactions of tethered proteins are poorly understood. Yet, because of the large role cell membranes play in enzymatic reactions, several reactions may take place where one of the proteins is bound to a fixed point in space. We develop a model to characterize tethered signalling between the phosphatase SHP-1 interacting with a tethered, phosphorylated protein. We compare our model to experimental data obtained using surface plasmon resonance (SPR). We show that a single SPR experiment recovers 5 independent biophysical/biochemical constants. We also compare the results between a three dimensional model and a two dimensional model. The work gives the opportunity to use known techniques to learn more about signalling processes, and new insights into how enzyme tethering alters cellular signalling. With support from the Mexican Council for Science and Technology (CONACyT), the Public Education Secretariat (SEP), and the Mexican National Autonomous University's Foundation (Fundacion UNAM).

  13. Polyneutron Chain Reactions

    International Nuclear Information System (INIS)

    John C. Fisher

    2000-01-01

    Although helium atoms do not form molecules, a sufficiently large number will bind into a stable liquid droplet. A comparable situation is expected for neutrons, with a sufficiently large number binding into a stable droplet of neutron matter. Such polyneutron droplets can be viewed as isotopes of an element with nuclear charge Z=0, tentatively denoted neutrium, symbol Nt. Because of the relatively weak binding of neutrons compared with that of a mix of neutrons and protons, the minimum number of neutrons required for stability of a droplet is fairly large. Early estimates of ∼60 may be reduced to a dozen or so by the BCS pairing interaction. The Nt entries with N≥12 are new to the table of isotopes. Because all of them are beta-unstable, none is expected to persist as a free particle. Yet, some may occasionally be produced by means to be described below, and it is of interest to examine their decay chains and their interactions with charged nuclei to ascertain how their presence might be revealed. Although these reactions are interesting, they cannot be taken seriously without identifying a source for the initial Nt isotope that begins the chain. Here, we consider possible interactions between 16 O and A Nt. Although there is no strong interaction between them, we can expect a very weak residual attraction that can form a loosely bound 16 O A Nt nuclear molecule. This is not a compound nucleus in the usual sense because, considered as fluids, the 16 O and A Nt droplets are immiscible. For a droplet with fewer than about 60 neutrons, beta decay of A Nt is prevented by the buildup of Coulomb energy associated with transforming A Nt into A H in close proximity to 16 O. Thus, it is possible that 16 O A Nt molecules can persist indefinitely and that a few of them may be present in ordinary water as supermassive oxygen nuclei. Because the binding of these molecules is weak, the A Nt component can tunnel to an adjacent nucleus, and if the adjacent nucleus is 18 O, a

  14. Boron atom reactions

    International Nuclear Information System (INIS)

    Estes, R.; Tabacco, M.B.; Digiuseppe, T.G.; Davidovits, P.

    1982-01-01

    The reaction rates of atomic boron with various epoxides have been measured in a flow tube apparatus. The bimolecular rate constants, in units of cm 3 molecule -1 s -1 , are: 1,2-epoxypropane (8.6 x 10 -11 ), 1,2-epoxybutane (8.8 x 10 -11 ), 1,2,3,4-diepoxybutane (5.5 x 10 -11 ), 1-chloro-2,3-epoxypropane (5.7 x 10 -11 ), and 1,2-epoxy-3,3,3-trichloropropane (1.5 x 10 -11 ). (orig.)

  15. Microfluidic polymerase chain reaction

    Science.gov (United States)

    Maltezos, George; Gomez, Alvaro; Zhong, Jiang; Gomez, Frank A.; Scherer, Axel

    2008-12-01

    We implement microfluidic technology to miniaturize a thermal cycling system for amplifying DNA fragments. By using a microfluidic thermal heat exchanger to cool a Peltier junction, we have demonstrated rapid heating and cooling of small volumes of solution. We use a miniature K-type thermocouple to provide a means for in situ sensing of the temperature inside the microrefrigeration system. By combining the thermocouple, two power supplies controlled by a relay system, and computer automation, we reproduce the function of a commercial polymerase chain reaction thermal cycler and demonstrate amplification of a DNA sample of about 1000 base pairs.

  16. Low Energy Nuclear Reactions?

    CERN Multimedia

    CERN. Geneva; Faccini, R.

    2014-01-01

    After an introduction to the controversial problem of Low Energy Nuclear Reactions (LENR) catalyzed by neutrons on metallic hydride surfaces we present the results of an experiment, made in collaboration with ENEA Labs in Frascati, to search neutrons from plasma discharges in electrolytic cells. The negative outcome of our experiment goes in the direction of ruling out those theoretical models expecting LENR to occur in condensed matter systems under specific conditions. Our criticism on the theoretical foundations of such models will also be presented.

  17. (d,pγ) Reactions and the surrogate reaction technique

    International Nuclear Information System (INIS)

    Cizewski, J.A.; Hatarik, R.; Jones, K.L.; Pain, S.D.; Thomas, J.S.; Johnson, M.S.; Bardayan, D.W.; Blackmon, J.C.; Smith, M.S.; Kozub, R.L.

    2007-01-01

    Neutron-capture reactions on neutron-rich nuclei are important to understand r-process nucleosynthesis, as well as applied needs such as stewardship science and nuclear energy. Because of the short half-lives of these species, it is not possible to measure these reactions directly with neutron beams on unstable targets. The (d,pγ) reaction with radioactive ion beams has been proposed as a surrogate reaction for (n,γ). Experiments to develop (d,pγ) techniques with radioactive ion beams and to demonstrate the efficacy of the (d,pγ) reaction as a surrogate for (n,γ) are discussed

  18. Hydrogen isotope exchange reactions

    International Nuclear Information System (INIS)

    Jones, J.R.

    1980-01-01

    The two most widely used methods for following hydrogen isotope exchange reactions, namely dedeuteriation and detritiation, involve in the first place the synthesis of an appropriately labelled compound. Rates of dedeuteriation are usually followed by measuring changes in the 1 H n.m.r. spectrum of the substrate (examples are given); the method not only gives the rate but also the site(s) of exchange. It is limited to rather slow reactions and is not as accurate as some of the other methods. The development of deuterium n.m.r. spectroscopy means that changes in the 2 H n.m.r. spectrum can also be used to measure rates of dedeuteriation. The development of liquid scintillation counting greatly eased the problem of how to detect weak β emitters; the attractions of tritium as a tracer were thereby much enhanced. Nowadays the study of rates of detritiation constitutes one of the most versatile and accurate methods of following hydrogen isotope exchange. Examples of the technique are given. (U.K.)

  19. The nuclear reaction matrix

    International Nuclear Information System (INIS)

    Krenciglowa, E.M.; Kung, C.L.; Kuo, T.T.S.; Osnes, E.; and Department of Physics, State University of New York at Stony Brook, Stony Brook, New York 11794)

    1976-01-01

    Different definitions of the reaction matrix G appropriate to the calculation of nuclear structure are reviewed and discussed. Qualitative physical arguments are presented in support of a two-step calculation of the G-matrix for finite nuclei. In the first step the high-energy excitations are included using orthogonalized plane-wave intermediate states, and in the second step the low-energy excitations are added in, using harmonic oscillator intermediate states. Accurate calculations of G-matrix elements for nuclear structure calculations in the Aapprox. =18 region are performed following this procedure and treating the Pauli exclusion operator Q 2 /sub p/ by the method of Tsai and Kuo. The treatment of Q 2 /sub p/, the effect of the intermediate-state spectrum and the energy dependence of the reaction matrix are investigated in detail. The present matrix elements are compared with various matrix elements given in the literature. In particular, close agreement is obtained with the matrix elements calculated by Kuo and Brown using approximate methods

  20. Nuclear reaction matrix

    International Nuclear Information System (INIS)

    Krenciglowa, E.M.; Kung, C.L.; Kuo, T.T.S.; Osnes, E.

    1975-01-01

    Different definitions of the reaction matrix G appropriate to the calculation of nuclear structure are reviewed and discussed. Qualitative physical arguments are presented in support of a two-step calculation of the G-matrix for finite nuclei. In the first step the high-energy excitations are included using orthogonalized plane-wave intermediate states, and in the second step the low-energy excitations are added in, using harmonic oscillator intermediate states. Accurate calculations of G-matrix elements for nuclear structure calculations in the A approximately 18 region are performed following this procedure and treating the Pauli exclusion operator Q/sub 2p/ by the method of Tsai and Kuo. The treatment of Q/sub 2p/, the effect of the intermediate-state spectrum and the energy dependence of the reaction matrix are investigated in detail. The present matrix elements are compared with various matrix elements given in the literature. In particular, close argument is obtained with the matrix elements calculated by Kuo and Brown using approximate methods

  1. Reaction Decoder Tool (RDT): extracting features from chemical reactions.

    Science.gov (United States)

    Rahman, Syed Asad; Torrance, Gilliean; Baldacci, Lorenzo; Martínez Cuesta, Sergio; Fenninger, Franz; Gopal, Nimish; Choudhary, Saket; May, John W; Holliday, Gemma L; Steinbeck, Christoph; Thornton, Janet M

    2016-07-01

    Extracting chemical features like Atom-Atom Mapping (AAM), Bond Changes (BCs) and Reaction Centres from biochemical reactions helps us understand the chemical composition of enzymatic reactions. Reaction Decoder is a robust command line tool, which performs this task with high accuracy. It supports standard chemical input/output exchange formats i.e. RXN/SMILES, computes AAM, highlights BCs and creates images of the mapped reaction. This aids in the analysis of metabolic pathways and the ability to perform comparative studies of chemical reactions based on these features. This software is implemented in Java, supported on Windows, Linux and Mac OSX, and freely available at https://github.com/asad/ReactionDecoder : asad@ebi.ac.uk or s9asad@gmail.com. © The Author 2016. Published by Oxford University Press.

  2. Ion-Molecule Reaction Dynamics.

    Science.gov (United States)

    Meyer, Jennifer; Wester, Roland

    2017-05-05

    We review the recent advances in the investigation of the dynamics of ion-molecule reactions. During the past decade, the combination of single-collision experiments in crossed ion and neutral beams with the velocity map ion imaging detection technique has enabled a wealth of studies on ion-molecule reactions. These methods, in combination with chemical dynamics simulations, have uncovered new and unexpected reaction mechanisms, such as the roundabout mechanism and the subtle influence of the leaving group in anion-molecule nucleophilic substitution reactions. For this important class of reactions, as well as for many fundamental cation-molecule reactions, the information obtained with crossed-beam imaging is discussed. The first steps toward understanding micro-solvation of ion-molecule reaction dynamics are presented. We conclude with the presentation of several interesting directions for future research.

  3. Kinetics of Bio-Reactions

    DEFF Research Database (Denmark)

    Villadsen, John

    2015-01-01

    . The models can be used in mass balances for design of processes under process conditions not yet studied experimentally. The value of the predictive kinetic model depends on the quality of the experimental data on which the model is based, and well-founded kinetic models for enzyme reactions have...... a considerable predictive power. This is also true for cell reaction models, when the model is used in its proper context. The chapter first discusses the kinetics for enzymatically catalyzed reactions (“enzyme reactions”). The kinetics can be derived from a mechanistic model. Then, the chapter derives empirical......his chapter predicts the specific rates of reaction by means of a mathematical expression, the kinetics of the reaction. This expression can be derived through a mechanistic interpretation of an enzymatically catalyzed reaction, but it is essentially of empirical nature for cell reactions...

  4. The Glaser–Hay reaction

    DEFF Research Database (Denmark)

    Vilhelmsen, Mie Højer; Jensen, Jonas; Tortzen, Christian

    2013-01-01

    . This unfavorable change in reaction profile could be avoided by adding molecular sieves to the reaction mixture, thereby removing the water that is accumulated from the air and produced in the reaction in which dioxygen acts as the oxidizing agent. Not unexpectedly, the stirring rate, and hence uptake of air (O2......), was found to have a significant effect on the rate of the reaction: The percentage of alkyne remaining after a certain time decreased linearly with the rate of stirring. On the basis of systematic studies, the optimized conditions for the coupling reaction using CuCl/TMEDA as the catalyst system......The oxidative Glaser–Hay coupling of two terminal alkynes to furnish a butadiyne is a key reaction for acetylenic scaffolding. Although the reaction is performed under rather simple conditions [CuCl/TMEDA/O2 (air)], the mechanism is still under debate. Herein we present detailed studies...

  5. Nuclear reactions an introduction

    CERN Document Server

    Paetz gen. Schieck, Hans

    2014-01-01

    Nuclei and nuclear reactions offer a unique setting for investigating three (and in some cases even all four) of the fundamental forces in nature. Nuclei have been shown – mainly by performing scattering experiments with electrons, muons, and neutrinos – to be extended objects with complex internal structures: constituent quarks; gluons, whose exchange binds the quarks together; sea-quarks, the ubiquitous virtual quark-antiquark pairs and, last but not least, clouds of virtual mesons, surrounding an inner nuclear region, their exchange being the source of the nucleon-nucleon interaction.   The interplay between the (mostly attractive) hadronic nucleon-nucleon interaction and the repulsive Coulomb force is responsible for the existence of nuclei; their degree of stability, expressed in the details and limits of the chart of nuclides; their rich structure and the variety of their interactions. Despite the impressive successes of the classical nuclear models and of ab-initio approaches, there is clearly no ...

  6. Chemical Reactions in Nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Levdansky, V.V.; Smolík, Jiří; Moravec, Pavel

    2010-01-01

    Roč. 83, č. 2 (2010), s. 401-405 ISSN 1062-0125 R&D Projects: GA ČR GA101/09/1633; GA AV ČR(CZ) IAA400720804; GA MPO(CZ) FR-TI1/548 Institutional research plan: CEZ:AV0Z40720504 Keywords : nanoparticle * chemical reaction * size effect Subject RIV: CF - Physical ; Theoretical Chemistry http://www.scopus.com/record/display.url?eid=2-s2.0-77955925089&origin=resultslist&sort=plf-f& src =s&st1=smolik%2cj&sid=j7atgxrpM26F0dojYSZsugJ%3a170&sot=b&sdt=b&sl=21&s=AUTHOR-NAME%28smolik%2cj%29&relpos=10&relpos=10&searchTerm=AUTHOR-NAME(smolik,j)

  7. Reversible and irreversible reaction fronts in two competing reactions system

    International Nuclear Information System (INIS)

    Sinder, M.; Taitelbaum, H.; Pelleg, J.

    2002-01-01

    A modeling of the non-equilibrium diffusion phenomena of the impurities in the semiconductors is based on the reaction-diffusion equations for local concentrations of the components. Through this approach a new feature, a reaction front, may be caused by reaction in diffusion profiles of the components. The asymptotic long-time properties of the reaction fronts in the system with initially separated components and two competing reactions: reversible A 1 +B↔C 1 and irreversible A 2 +B→C 2 are studied in this work. It is assumed that the backward constant of the reaction A 1 +B↔C 1 is small. The dynamics of the system is described as a cross-over between the 'irreversible' regime for small times and the 'reversible' regime for large times. It is shown that the 'irreversible' regime is characterized by single reaction zone, in which both reactions occur. The two reaction fronts, reversible A 1 +B↔C 1 and irreversible A 2 +C 1 →A 1 +C 2 appear in the 'reversible' regime. Numerical computing of the mean-field kinetics equations confirms these asymptotic results. The experimental tests of the theoretical predictions relating to the diffusion phenomena in semiconductors are discussed

  8. Immediate hypersensitivity reaction with mango.

    Science.gov (United States)

    Shah, Ashok; Gera, Kamal

    2014-01-01

    Hypersensitivity to the fruit mango is extremely rare and can exhibit either as immediate or delayed reactions. Since 1939, only 22 patients (10 with immediate type I reactions and 12 with delayed) have been documented with allergy to mango. History of atopy and geographical region may influence the type of reaction. Immediate reactions occurred most often in patients with history of atopy, while delayed reactions developed in non-atopic individuals. Clustering of delayed hypersensitivity reports from Australia and immediate reactions from Europe has been documented. We report a 50-year-old man with immediate type I hypersensitivity to mango, who developed cough, wheezing dyspnoea, generalised itching and abdominal discomfort after ingestion of mango. Life threatening event can also happen making it imperative to diagnose on time, so as to prevent significant morbidity and potential mortality.

  9. Adverse Reactions to Biologic Therapy.

    Science.gov (United States)

    Patel, Sheenal V; Khan, David A

    2017-05-01

    Biologic therapies are emerging as a significant therapeutic option for many with debilitating inflammatory and autoimmune conditions. As expansion in the number of FDA-approved agents continue to be seen, more unanticipated adverse reactions are likely to occur. Currently, the diagnostic tools, including skin testing and in vitro testing, to evaluate for immediate hypersensitivity reactions are insufficient. In this review, management strategies for common acute infusion reactions, injection site reactions, and immediate reactions suggestive of IgE-mediated mechanisms are discussed. Desensitization can be considered for reactions suggestive of IgE-mediated mechanisms, but allergists/immunologists should be involved in managing these patients. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. [Adverse cutaneous reactions to drugs].

    Science.gov (United States)

    Suástegui-Rodríguez, Irvin; Campos-Jiménez, Karin Ivette; Domínguez-Cherit, Judith; Méndez-Flores, Silvia

    2018-01-01

    Adverse cutaneous reactions to drugs are any undesirable change in the structure or function of the skin. These are among the adverse side effects to common drugs. The most commonly implicated drugs are antibiotics and anticonvulsants. Cutaneous clinical manifestations are diverse ranging from mild or moderate reactions, such as urticaria and maculopapular rash, to severe cutaneous adverse reactions (SCAR), which are known due to their high morbidity and mortality (among these: Stevens-Johnson syndrome, toxic epidermal necrolysis (TEN), and drug reaction with eosinophilia and systemic symptoms (DRESS). The clinical pattern, etiology, prognosis and treatment differ among these skin reactions, which is why it is necessary a clear diagnosis based on a comprehensive clinical examination, skin biopsy, and specific laboratory tests. The therapeutic options depend on the clinical diagnosis. For all reactions, a symptomatic and adequate supportive therapy is necessary; in some cases, a systemic immunomodulatory therapy can be useful.

  11. Nuclear reactions as structure probes

    International Nuclear Information System (INIS)

    Fernandez, Bernard; Cugnon, Joseph; Roussel-Chomaz, Patricia; Sparenberg, Jean-Marc; Oliveira Santos, Francois de; Bauge, Eric; Poves, Alfredo; Keeley, Nicholas; Simenel, Cedric; Avez, Benoit; Lacroix, Denis; Baye, Daniel; Cortina-Gil, Dolores; Pons, Alexandre

    2007-09-01

    This publication gathers courses which aim at giving a view on new experiments which are performed by using radioactive beams, notably low intensity beams, in different accelerators, and allow the structure of very exotic nuclei to be characterized. Experimental as well as theoretical aspects are thus addressed. The contributions propose: a brief history of nuclear reactions and of instruments used to study them from the discovery of nucleus to the DWBA (Distorted Wave Born Approximation); an overview of nuclear reactions; experimental techniques; the theory of collisions at low energy; resonant elastic scattering, inelastic scattering and astrophysical reactions; to probe nuclear structure with nucleons; shell model and spectroscopic factors; analysis of transfer reactions and determination of spectroscopic factors; microscopic approaches of nuclear dynamics; theoretical aspects of dissociation reactions; experimental aspects of knockout reactions; research in oenology with the chemical characterisation of defective ageing of dry white wines

  12. Nuclear astrophysics from direct reactions

    Energy Technology Data Exchange (ETDEWEB)

    Bertulani, C. [Department of Physics, Texas A and M University, Commerce, TX 75429 (United States)]. e-mail: carlos_bertulani@tamu-commerce.edu

    2008-12-15

    Accurate nuclear reaction rates are needed for primordial nucleosynthesis and hydrostatic burning in stars. The relevant reactions are extremely difficult to measure directly in the laboratory at the small astrophysical energies. In recent years direct reactions have been developed and applied to extract low-energy astrophysical S-factors. These methods require a combination of new experimental techniques and theoretical efforts, which are the subject of this presentation. (Author)

  13. Multistep processes in nuclear reactions

    International Nuclear Information System (INIS)

    Hodgson, P.E.

    1988-01-01

    The theories of nuclear reactions are reviewed with particular attention to the recent work on multistep processes. The evidence for compound nucleus and direct interaction reactions is described together with the results of comparisons between theories and experimental data. These theories have now proved inadequate, and there is evidence for multistep processes that take place after the initial direct stage but long before the attainment of the statistical equilibrium characteristic of compound nucleus processes. The theories of these reactions are described and it is shown how they can account for the experimental data and thus give a comprehensive understanding of nuclear reactions. (author)

  14. Dynamic Reaction Figures: An Integrative Vehicle for Understanding Chemical Reactions

    Science.gov (United States)

    Schultz, Emeric

    2008-01-01

    A highly flexible learning tool, referred to as a dynamic reaction figure, is described. Application of these figures can (i) yield the correct chemical equation by simply following a set of menu driven directions; (ii) present the underlying "mechanism" in chemical reactions; and (iii) help to solve quantitative problems in a number of different…

  15. Free Radical Reactions in Food.

    Science.gov (United States)

    Taub, Irwin A.

    1984-01-01

    Discusses reactions of free radicals that determine the chemistry of many fresh, processed, and stored foods. Focuses on reactions involving ascorbic acid, myoglobin, and palmitate radicals as representative radicals derived from a vitamin, metallo-protein, and saturated lipid. Basic concepts related to free radical structure, formation, and…

  16. Adverse Reactions to Hallucinogenic Drugs.

    Science.gov (United States)

    Meyer, Roger E. , Ed.

    This reports a conference of psychologists, psychiatrists, geneticists and others concerned with the biological and psychological effects of lysergic acid diethylamide and other hallucinogenic drugs. Clinical data are presented on adverse drug reactions. The difficulty of determining the causes of adverse reactions is discussed, as are different…

  17. "Greening up" the Suzuki Reaction

    Science.gov (United States)

    Aktoudianakis, Evangelos; Chan, Elton; Edward, Amanda R.; Jarosz, Isabel; Lee, Vicki; Mui, Leo; Thatipamala, Sonya S.; Dicks, Andrew P.

    2008-01-01

    This article describes the rapid, green synthesis of a biaryl compound (4-phenylphenol) via a Pd(0)-catalyzed Suzuki cross-coupling reaction in water. Mild reaction conditions and operational simplicity makes this experiment especially amenable to both mid- and upper-level undergraduates. The methodology exposes students to purely aqueous…

  18. Effective reaction rates for diffusion-limited reaction cycles.

    Science.gov (United States)

    Nałęcz-Jawecki, Paweł; Szymańska, Paulina; Kochańczyk, Marek; Miękisz, Jacek; Lipniacki, Tomasz

    2015-12-07

    Biological signals in cells are transmitted with the use of reaction cycles, such as the phosphorylation-dephosphorylation cycle, in which substrate is modified by antagonistic enzymes. An appreciable share of such reactions takes place in crowded environments of two-dimensional structures, such as plasma membrane or intracellular membranes, and is expected to be diffusion-controlled. In this work, starting from the microscopic bimolecular reaction rate constants and using estimates of the mean first-passage time for an enzyme-substrate encounter, we derive diffusion-dependent effective macroscopic reaction rate coefficients (EMRRC) for a generic reaction cycle. Each EMRRC was found to be half of the harmonic average of the microscopic rate constant (phosphorylation c or dephosphorylation d), and the effective (crowding-dependent) motility divided by a slowly decreasing logarithmic function of the sum of the enzyme concentrations. This implies that when c and d differ, the two EMRRCs scale differently with the motility, rendering the steady-state fraction of phosphorylated substrate molecules diffusion-dependent. Analytical predictions are verified using kinetic Monte Carlo simulations on the two-dimensional triangular lattice at the single-molecule resolution. It is demonstrated that the proposed formulas estimate the steady-state concentrations and effective reaction rates for different sets of microscopic reaction rates and concentrations of reactants, including a non-trivial example where with increasing diffusivity the fraction of phosphorylated substrate molecules changes from 10% to 90%.

  19. Reaction rates for reaction-diffusion kinetics on unstructured meshes.

    Science.gov (United States)

    Hellander, Stefan; Petzold, Linda

    2017-02-14

    The reaction-diffusion master equation is a stochastic model often utilized in the study of biochemical reaction networks in living cells. It is applied when the spatial distribution of molecules is important to the dynamics of the system. A viable approach to resolve the complex geometry of cells accurately is to discretize space with an unstructured mesh. Diffusion is modeled as discrete jumps between nodes on the mesh, and the diffusion jump rates can be obtained through a discretization of the diffusion equation on the mesh. Reactions can occur when molecules occupy the same voxel. In this paper, we develop a method for computing accurate reaction rates between molecules occupying the same voxel in an unstructured mesh. For large voxels, these rates are known to be well approximated by the reaction rates derived by Collins and Kimball, but as the mesh is refined, no analytical expression for the rates exists. We reduce the problem of computing accurate reaction rates to a pure preprocessing step, depending only on the mesh and not on the model parameters, and we devise an efficient numerical scheme to estimate them to high accuracy. We show in several numerical examples that as we refine the mesh, the results obtained with the reaction-diffusion master equation approach those of a more fine-grained Smoluchowski particle-tracking model.

  20. Reaction path analysis of sodium-water reaction phenomena in support of chemical reaction model development

    International Nuclear Information System (INIS)

    Kikuchi, Shin; Ohshima, Hiroyuki; Hashimoto, Kenro

    2011-01-01

    Computational study of the sodium-water reaction at the gas (water) - liquid (sodium) interface has been carried out using ab initio (first-principle) method. A possible reaction channel has been identified for the stepwise OH bond dissociations of a single water molecule. The energetics including the binding energy of a water molecule to the sodium surface, the activation energies of the bond cleavages, and the reaction energies, have been evaluated, and the rate constants of the first and second OH bond-breakings have been compared. The results are used as the basis for constructing the chemical reaction model used in a multi-dimensional sodium-water reaction code, SERAPHIM, being developed by JAEA toward the safety assessment of the steam generator (SG) in a sodium-cooled fast reactor (SFR). (author)

  1. Integrated Microreactors for Reaction Automation: New Approaches to Reaction Development

    Science.gov (United States)

    McMullen, Jonathan P.; Jensen, Klavs F.

    2010-07-01

    Applications of microsystems (microreactors) in continuous-flow chemistry have expanded rapidly over the past two decades, with numerous reports of higher conversions and yields compared to conventional batch benchtop equipment. Synthesis applications are enhanced by chemical information gained from integrating microreactor components with sensors, actuators, and automated fluid handling. Moreover, miniaturized systems allow experiments on well-defined samples at conditions not easily accessed by conventional means, such as reactions at high pressure and temperatures. The wealth of synthesis information that could potentially be acquired through use of microreactors integrated with physical sensors and analytical chemistry techniques for online reaction monitoring has not yet been well explored. The increased efficiency resulting from use of continuous-flow microreactor platforms to automate reaction screening and optimization encourages a shift from current batchwise chemical reaction development to this new approach. We review advances in this new area and provide application examples of online monitoring and automation.

  2. Fusion chain reaction - a chain reaction with charged particles

    International Nuclear Information System (INIS)

    Peres, A.; Shvarts, D.

    1975-01-01

    When a DT-plasma is compressed to very high density, the particles resulting from nuclear reactions give their energy mostly to D and T ions, by nuclear collisions, rather than to electrons as usual. Fusion can thus proceed as a chain reaction, without the need of thermonuclear temperatures. In this paper, we derive relations for the suprathermal ion population created by a fusion reaction. Numerical integration of these equations shows that a chain reaction can proceed in a cold infinite DT-plasma at densities above 8.4x10 27 ions.cm -3 . Seeding the plasma with a small amount of 6 Li reduces the critical density to 7.2x10 27 ions.cm -3 (140000times the normal solid density). (author)

  3. The Paterno-Buchi reaction

    DEFF Research Database (Denmark)

    Brogaard, Rasmus Yding; Schalk, Oliver; Boguslavskiy, Andrey E.

    2012-01-01

    The Paternò-Büchi (PB) reaction between an excited carbonyl compound and an alkene has been widely studied, but so far little is known about the excited-state dynamics of the reaction. In this investigation, we used a compound in which a formyl and a vinyl group are attached to a [2.2]paracycloph......The Paternò-Büchi (PB) reaction between an excited carbonyl compound and an alkene has been widely studied, but so far little is known about the excited-state dynamics of the reaction. In this investigation, we used a compound in which a formyl and a vinyl group are attached to a [2...... within two picoseconds competes efficiently with the reaction in the singlet manifold. Thus, the PB reaction in this model system takes place in the triplet state on a time scale of nanoseconds. This result stresses the importance of triplet states in the excited-state pathway of the PB reaction...

  4. Palladium-catalyzed coupling reactions

    CERN Document Server

    Molnár, Árpád

    2013-01-01

    This handbook and ready reference brings together all significant issues of practical importance for interested readers in one single volume. While covering homogeneous and heterogeneous catalysis, the text is unique in focusing on such important aspects as using different reaction media, microwave techniques or catalyst recycling. It also provides a comprehensive treatment of modern-day coupling reactions and emphasizes those topics that show potential for future development, such as continuous flow systems, water as a reaction medium, and catalyst immobilization, among others. With i

  5. Catalytic Organometallic Reactions of Ammonia

    Science.gov (United States)

    Klinkenberg, Jessica L.

    2012-01-01

    Until recently, ammonia had rarely succumbed to catalytic transformations with homogeneous catalysts, and the development of such reactions that are selective for the formation of single products under mild conditions has encountered numerous challenges. However, recently developed catalysts have allowed several classes of reactions to create products with nitrogen-containing functional groups from ammonia. These reactions include hydroaminomethylation, reductive amination, alkylation, allylic substitution, hydroamination, and cross-coupling. This Minireview describes examples of these processes and the factors that control catalyst activity and selectivity. PMID:20857466

  6. Chemical potential and reaction electronic flux in symmetry controlled reactions.

    Science.gov (United States)

    Vogt-Geisse, Stefan; Toro-Labbé, Alejandro

    2016-07-15

    In symmetry controlled reactions, orbital degeneracies among orbitals of different symmetries can occur along a reaction coordinate. In such case Koopmans' theorem and the finite difference approximation provide a chemical potential profile with nondifferentiable points. This results in an ill-defined reaction electronic flux (REF) profile, since it is defined as the derivative of the chemical potential with respect to the reaction coordinate. To overcome this deficiency, we propose a new way for the calculation of the chemical potential based on a many orbital approach, suitable for reactions in which symmetry is preserved. This new approach gives rise to a new descriptor: symmetry adapted chemical potential (SA-CP), which is the chemical potential corresponding to a given irreducible representation of a symmetry group. A corresponding symmetry adapted reaction electronic flux (SA-REF) is also obtained. Using this approach smooth chemical potential profiles and well defined REFs are achieved. An application of SA-CP and SA-REF is presented by studying the Cs enol-keto tautomerization of thioformic acid. Two SA-REFs are obtained, JA'(ξ) and JA'' (ξ). It is found that the tautomerization proceeds via an in-plane delocalized 3-center 4-electron O-H-S hypervalent bond which is predicted to exist only in the transition state (TS) region. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  7. Reactions with light exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Lichtenthäler, R.; Faria, P.N. de; Pires, K.C.C.; Lepine-Szily, A.; Guimaraes, V.; Mendes Junior, D.R.; Assuncao, M.; Barioni, A.; Morcelle, V.; Morais, M.C.; Camargo Junior, O.; Alcantara Nuñez, J. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Fisica; Moro, A.M. [Departamento de FAMN, Universidad de Sevilla, Sevilla (Spain); Arazi, A. [Laboratorio Tandar, Departamento de Fisica, Comision Nacional de Energia Atomica (CNEA), Buenos Aires (Argentina); Rodriguez-Gallardo, M. [Instituto de Estructura de la Materia, CSIC, Madrid (Spain)

    2014-07-01

    Experimental cross sections for the {sup 6}He+{sup 120}Sn are analysed. Elastic scattering angular distributions and alpha particle production cross sections have been measured and are compared with the total reaction cross sections. (author)

  8. Method for conducting exothermic reactions

    Science.gov (United States)

    Smith, L. Jr.; Hearn, D.; Jones, E.M. Jr.

    1993-01-05

    A liquid phase process for oligomerization of C[sub 4] and C[sub 5] isoolefins or the etherification thereof with C[sub 1] to C[sub 6] alcohols wherein the reactants are contacted in a reactor with a fixed bed acid cation exchange resin catalyst at an LHSV of 5 to 20, pressure of 0 to 400 psig and temperature of 120 to 300 F. wherein the improvement is the operation of the reactor at a pressure to maintain the reaction mixture at its boiling point whereby at least a portion but less than all of the reaction mixture is vaporized. By operating at the boiling point and allowing a portion of the reaction mixture to vaporize, the exothermic heat of reaction is dissipated by the formation of more boil up and the temperature in the reactor is controlled.

  9. Analysis of kinetic reaction mechanisms

    CERN Document Server

    Turányi, Tamás

    2014-01-01

    Chemical processes in many fields of science and technology, including combustion, atmospheric chemistry, environmental modelling, process engineering, and systems biology, can be described by detailed reaction mechanisms consisting of numerous reaction steps. This book describes methods for the analysis of reaction mechanisms that are applicable in all these fields. Topics addressed include: how sensitivity and uncertainty analyses allow the calculation of the overall uncertainty of simulation results and the identification of the most important input parameters, the ways in which mechanisms can be reduced without losing important kinetic and dynamic detail, and the application of reduced models for more accurate engineering optimizations. This monograph is invaluable for researchers and engineers dealing with detailed reaction mechanisms, but is also useful for graduate students of related courses in chemistry, mechanical engineering, energy and environmental science and biology.

  10. Drug Reactions in Oral Mucosa

    Directory of Open Access Journals (Sweden)

    Emine Derviş

    2012-12-01

    Full Text Available Both immunologic and nonimmunologic drug reactions can be seen in oral mucosa. Since considerable number of these reactions heals spontaneously without being noticed by the patients, exact frequency of the lesions is unknown. Most common lesions are xerostomia, taste disorders, mucosal ulcerations and edema. In this article, oral lesions resulting from drug intake similar to those from oral lesions of local and systemic diseases, and diagnostic problems caused by these similarities, have been reviewed.

  11. Medium effects in direct reactions

    International Nuclear Information System (INIS)

    Karakoc, M; Bertulani, C

    2013-01-01

    We discuss medium corrections of the nucleon-nucleon (NN) cross sections and their influence on direct reactions at intermediate energies ≳50 MeV/nucleon. The results obtained with free NN cross sections are compared with those obtained with a geometrical treatment of Pauli-blocking and Dirac-Bruecker methods. We show that medium corrections may lead to sizable modifications for collisions at intermediate energies and that they are more pronounced in reactions involving weakly bound nuclei.

  12. Late reaction, persistent reaction and doubtful allergic reaction: The problems of interpretation

    Directory of Open Access Journals (Sweden)

    Sarma Nilendu

    2009-01-01

    Full Text Available The standard method of patch test reading is to read the test site for any positive allergy at 48hr and then again at 72/96 hr. A late reading on the seventh day is also advised to exclude the irritant reaction (IR and to notice some delayed development of allergic reaction. However, multiple visits are often difficult for the patient; therefore, this late reading is sometimes omitted. Here a case of plantar hyperkeratosis, due to allergic contact dermatitis, is reported with some insight into interpretation of the patch test. The patient showed delayed patch test reaction to formaldehyde and colophony, which has never been reported before.

  13. Reciprocity theory of homogeneous reactions

    Science.gov (United States)

    Agbormbai, Adolf A.

    1990-03-01

    The reciprocity formalism is applied to the homogeneous gaseous reactions in which the structure of the participating molecules changes upon collision with one another, resulting in a change in the composition of the gas. The approach is applied to various classes of dissociation, recombination, rearrangement, ionizing, and photochemical reactions. It is shown that for the principle of reciprocity to be satisfied it is necessary that all chemical reactions exist in complementary pairs which consist of the forward and backward reactions. The backward reaction may be described by either the reverse or inverse process. The forward and backward processes must satisfy the same reciprocity equation. Because the number of dynamical variables is usually unbalanced on both sides of a chemical equation, it is necessary that this balance be established by including as many of the dynamical variables as needed before the reciprocity equation can be formulated. Statistical transformation models of the reactions are formulated. The models are classified under the titles free exchange, restricted exchange and simplified restricted exchange. The special equations for the forward and backward processes are obtained. The models are consistent with the H theorem and Le Chatelier's principle. The models are also formulated in the context of the direct simulation Monte Carlo method.

  14. Nuclear Reactions for Astrophysics and Other Applications

    Energy Technology Data Exchange (ETDEWEB)

    Escher, J E; Burke, J T; Dietrich, F S; Scielzo, N D; Ressler, J J

    2011-03-01

    Cross sections for compound-nuclear reactions are required for many applications. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

  15. Reaction rates for mesoscopic reaction-diffusion kinetics.

    Science.gov (United States)

    Hellander, Stefan; Hellander, Andreas; Petzold, Linda

    2015-02-01

    The mesoscopic reaction-diffusion master equation (RDME) is a popular modeling framework frequently applied to stochastic reaction-diffusion kinetics in systems biology. The RDME is derived from assumptions about the underlying physical properties of the system, and it may produce unphysical results for models where those assumptions fail. In that case, other more comprehensive models are better suited, such as hard-sphere Brownian dynamics (BD). Although the RDME is a model in its own right, and not inferred from any specific microscale model, it proves useful to attempt to approximate a microscale model by a specific choice of mesoscopic reaction rates. In this paper we derive mesoscopic scale-dependent reaction rates by matching certain statistics of the RDME solution to statistics of the solution of a widely used microscopic BD model: the Smoluchowski model with a Robin boundary condition at the reaction radius of two molecules. We also establish fundamental limits on the range of mesh resolutions for which this approach yields accurate results and show both theoretically and in numerical examples that as we approach the lower fundamental limit, the mesoscopic dynamics approach the microscopic dynamics. We show that for mesh sizes below the fundamental lower limit, results are less accurate. Thus, the lower limit determines the mesh size for which we obtain the most accurate results.

  16. Reaction rates for a generalized reaction-diffusion master equation.

    Science.gov (United States)

    Hellander, Stefan; Petzold, Linda

    2016-01-01

    It has been established that there is an inherent limit to the accuracy of the reaction-diffusion master equation. Specifically, there exists a fundamental lower bound on the mesh size, below which the accuracy deteriorates as the mesh is refined further. In this paper we extend the standard reaction-diffusion master equation to allow molecules occupying neighboring voxels to react, in contrast to the traditional approach, in which molecules react only when occupying the same voxel. We derive reaction rates, in two dimensions as well as three dimensions, to obtain an optimal match to the more fine-grained Smoluchowski model and show in two numerical examples that the extended algorithm is accurate for a wide range of mesh sizes, allowing us to simulate systems that are intractable with the standard reaction-diffusion master equation. In addition, we show that for mesh sizes above the fundamental lower limit of the standard algorithm, the generalized algorithm reduces to the standard algorithm. We derive a lower limit for the generalized algorithm which, in both two dimensions and three dimensions, is of the order of the reaction radius of a reacting pair of molecules.

  17. Concordant Chemical Reaction Networks and the Species-Reaction Graph

    Science.gov (United States)

    Shinar, Guy; Feinberg, Martin

    2015-01-01

    In a recent paper it was shown that, for chemical reaction networks possessing a subtle structural property called concordance, dynamical behavior of a very circumscribed (and largely stable) kind is enforced, so long as the kinetics lies within the very broad and natural weakly monotonic class. In particular, multiple equilibria are precluded, as are degenerate positive equilibria. Moreover, under certain circumstances, also related to concordance, all real eigenvalues associated with a positive equilibrium are negative. Although concordance of a reaction network can be decided by readily available computational means, we show here that, when a nondegenerate network’s Species-Reaction Graph satisfies certain mild conditions, concordance and its dynamical consequences are ensured. These conditions are weaker than earlier ones invoked to establish kinetic system injectivity, which, in turn, is just one ramification of network concordance. Because the Species-Reaction Graph resembles pathway depictions often drawn by biochemists, results here expand the possibility of inferring significant dynamical information directly from standard biochemical reaction diagrams. PMID:22940368

  18. Carbonitriding reactions of diatomaceous earth: phase evolution and reaction mechanisms

    Directory of Open Access Journals (Sweden)

    BRANKO MATOVIC

    2006-06-01

    Full Text Available The possibility of using diatomaceous earth as Si precursor for low temperature synthesis of non-oxide powders by carbothermal reduction-nitridation was studied. It was found that carbonitriding reactions produce phases of the Si–Al–O–N system. Already at 1300 °C, nanosized, non-oxide powders were obtained. The comparatively low reaction temperatures is attributred to the nano-porous nature of the raw material. The evolution of crystalline phases proceeded via many intermediate stages. The powders were characterized by X-ray and SEM investigations. The results showed that diatomaceous earth can be a very effective source for obtaining non-oxide powders.

  19. A comprehensive survey of nuclear reactions; Panorama des reactions nucleaires

    Energy Technology Data Exchange (ETDEWEB)

    Cugnon, J. [Liege Univ., IFPA, AGO Dept. (Belgium)

    2007-07-01

    The various mechanisms of nuclear reactions are surveyed and classified in different regimes, based on the notions of coherent mechanisms and hard versus soft processes. The emphasis is put on the concepts at the basis of the understanding of these regimes and on the elements of nuclear structure which are involved in these different regimes, as well as the on the possibility of extracting this information. Due to lack of space and for pedagogical reasons, the discussion is limited to nucleon-induced and light-ion-induced reactions. However, a few remarks are given concerning some specific probes, such as weakly bound projectiles or neutron-rich nuclei. (author)

  20. Biomarkers of adverse drug reactions.

    Science.gov (United States)

    Carr, Daniel F; Pirmohamed, Munir

    2018-02-01

    Adverse drug reactions can be caused by a wide range of therapeutics. Adverse drug reactions affect many bodily organ systems and vary widely in severity. Milder adverse drug reactions often resolve quickly following withdrawal of the casual drug or sometimes after dose reduction. Some adverse drug reactions are severe and lead to significant organ/tissue injury which can be fatal. Adverse drug reactions also represent a financial burden to both healthcare providers and the pharmaceutical industry. Thus, a number of stakeholders would benefit from development of new, robust biomarkers for the prediction, diagnosis, and prognostication of adverse drug reactions. There has been significant recent progress in identifying predictive genomic biomarkers with the potential to be used in clinical settings to reduce the burden of adverse drug reactions. These have included biomarkers that can be used to alter drug dose (for example, Thiopurine methyltransferase (TPMT) and azathioprine dose) and drug choice. The latter have in particular included human leukocyte antigen (HLA) biomarkers which identify susceptibility to immune-mediated injuries to major organs such as skin, liver, and bone marrow from a variety of drugs. This review covers both the current state of the art with regard to genomic adverse drug reaction biomarkers. We also review circulating biomarkers that have the potential to be used for both diagnosis and prognosis, and have the added advantage of providing mechanistic information. In the future, we will not be relying on single biomarkers (genomic/non-genomic), but on multiple biomarker panels, integrated through the application of different omics technologies, which will provide information on predisposition, early diagnosis, prognosis, and mechanisms. Impact statement • Genetic and circulating biomarkers present significant opportunities to personalize patient therapy to minimize the risk of adverse drug reactions. ADRs are a significant heath issue

  1. Spallation reactions - physics and applications

    International Nuclear Information System (INIS)

    Kelic, A.; Ricciardi, M.; Schmidt, K-H.

    2009-01-01

    Spallation reactions have become an ideal tool for studying the equation of state and thermal instabilities of nuclear matter. In astrophysics, the interactions of cosmic rays with the interstellar medium have to be understood in detail for deducing their original composition and their production mechanisms. Renewed interest in spallation reactions with protons around 1 GeV came up recently with the developments of spallation neutron sources. The project of an accelerator-driven system (ADS) as a technological solution for incinerating the radioactive waste even intensified the efforts for better understanding the physics involved in the spallation process. Experiments on spallation reactions were performed for determining the production cross sections and properties of particles, fragments and heavy residues. Traditional experiments on heavy residues, performed in direct kinematics, were limited to the direct observation of long-lived radioactive nuclides and did not provide detailed information on the kinematics of the reaction. Therefore, an innovative experimental method has been developed, based on inverse kinematics, which allowed to identify all reaction residues in-flight, using the high resolution magnetic spectrometer FRS of GSL Darmstadt. It also gives direct access to the reaction kinematics. An experimental campaign has been carried out in a Europe-wide collaboration, investigating the spallation of several nuclei ranging from 56 Fe to 238 U Complementary experiments were performed with a full-acceptance detection system, yielding total fission cross sections. Recently, another detection system using the large acceptance ALADIN dipole and the LAND neutron detector was introduced to measure light particles in coincidence with the heavy residues. Another intense activity was dedicated to developing codes, which cover nuclear reactions occurring in an ADS. The first phase of the reaction is successfully described by a sequence of quasi-free nucleon

  2. [Histopathology of cutaneous drug reactions].

    Science.gov (United States)

    Ortonne, Nicolas

    2018-02-01

    There are many different types of cutaneous adverse reactions. The most classical reactions are driven by T lymphocytes that specifically react towards a drug, with an individual genetic susceptibility linked to certain type I major histocompatibility complex alleles. These reactions are characterized by a wide variety of clinical and histopathological presentations, and a wide range of severity. The most frequent entity is the maculopapular rash, while the most aggressive forms are the Steven-Johnson syndrome and toxic epidermal necrolysis (SJS-TEN). The histopathological alterations associated to each of these syndromes have been better described in the literature during the past 10 years, encompassing non-specific lesions, as in most drug induced maculopapular rashes, to more specific inflammatory patterns. The finding of confluent apoptotic keratinocytes with epidermal detachment is the prototypical aspect of SJS-TEN. There are however numerous pitfalls, and a similar aspect to those observed in each cutaneous drug reactions entities can be found in other diseases. DRESS syndrome can indeed present with dense and epidermotropic T-cell infiltrate, sometimes with nuclear atypias, and thus can be difficult to distinguish from a primary or secondary cutaneous T-cell lymphoma. The diagnosis of cutaneous adverse reactions relies on a clinical-pathological confrontation and requires an accurate evaluation of drug imputability. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Fatal anaphylactic reaction during anesthesia

    Directory of Open Access Journals (Sweden)

    Izidor Kern

    2012-01-01

    Full Text Available Background: Incidence of anaphylactic reactions occuring during anesthesia is not known. They occur most often in the induction  phase and can present with different levels of severity, also as an anaphylactic shock. Neuromuscular blocking drugs are the most frequently involved substances.Case presentation: We  report a case of a 77-year old female patient with granulomatous inflammation of unknown etiology. Surgical  biopsy of a neck lymph node was indicated. During the induction of anesthesia using propofol and succinylcholine she developed severe anaphylactic reaction presented with bronchospasm and cardiac arrest. Despite 80 min continous cardiopulmonary resuscitation the patient died. Elevated tryptase level in the patient’s blood sample taken before death confirmed anaphylactic reaction. On autopsy we confirmed the tuberculous etiology of generalized granulomatous inflammation.Conclusions: It is important to recognize anaphylactic reaction during anesthesia early and to take adequate measures in order to prevent unfavorable outcome. Tryptase assay of a blood sample taken during life or postmortem may help to identify anaphylactic reaction.

  4. Topics in heavy ion reactions

    International Nuclear Information System (INIS)

    Feshbach, H.

    1980-01-01

    Methods are discussed which, by straightforward extensions of currently available concepts and procedures, can be used for the description of reactions induced by heavy ions. The first section describes a nuclear Weiszaecker-Williams method for peripheral collisions of nuclei which is here extended to pion production in peripheral collisions. The second section emphasizes the relationship between the collision of an energetic proton and that of an energetic heavy ion with a nucleus. The comparatively remarkable behavior of the observed energy dependence of the angular distribution and average energy of the fragments produced in proton collision is described and a qualitative explanation offered. The third section is concerned with the'pre-equilibrium' reactions as well as the multi-step direct reactions which are known to play an important role in heavy ion collisions. A statistical theory of multi-step direct and multi-step compound reactions providing explicit expressions for the energy and angular distributions is formulated. A diffusion equation in momentum space is obtained as an approximation to these formulas. The extension of these results to heavy ion reactions in which phenomena involving deformation, mass and charge transfer and multi-particle final states are important, is made. (author)

  5. Combustion kinetics and reaction pathways

    Energy Technology Data Exchange (ETDEWEB)

    Klemm, R.B.; Sutherland, J.W. [Brookhaven National Laboratory, Upton, NY (United States)

    1993-12-01

    This project is focused on the fundamental chemistry of combustion. The overall objectives are to determine rate constants for elementary reactions and to elucidate the pathways of multichannel reactions. A multitechnique approach that features three independent experiments provides unique capabilities in performing reliable kinetic measurements over an exceptionally wide range in temperature, 300 to 2500 K. Recent kinetic work has focused on experimental studies and theoretical calculations of the methane dissociation system (CH{sub 4} + Ar {yields} CH{sub 3} + H + Ar and H + CH{sub 4} {yields} CH{sub 3} + H{sub 2}). Additionally, a discharge flow-photoionization mass spectrometer (DF-PIMS) experiment is used to determine branching fractions for multichannel reactions and to measure ionization thresholds of free radicals. Thus, these photoionization experiments generate data that are relevant to both reaction pathways studies (reaction dynamics) and fundamental thermochemical research. Two distinct advantages of performing PIMS with high intensity, tunable vacuum ultraviolet light at the National Synchrotron Light Source are high detection sensitivity and exceptional selectivity in monitoring radical species.

  6. Inorganic Reaction Mechanisms Part II: Homogeneous Catalysis

    Science.gov (United States)

    Cooke, D. O.

    1976-01-01

    Suggests several mechanisms for catalysis by metal ion complexes. Discusses the principal factors of importance in these catalysis reactions and suggests reactions suitable for laboratory study. (MLH)

  7. A unified diabatic description for electron transfer reactions, isomerization reactions, proton transfer reactions, and aromaticity.

    Science.gov (United States)

    Reimers, Jeffrey R; McKemmish, Laura K; McKenzie, Ross H; Hush, Noel S

    2015-10-14

    While diabatic approaches are ubiquitous for the understanding of electron-transfer reactions and have been mooted as being of general relevance, alternate applications have not been able to unify the same wide range of observed spectroscopic and kinetic properties. The cause of this is identified as the fundamentally different orbital configurations involved: charge-transfer phenomena involve typically either 1 or 3 electrons in two orbitals whereas most reactions are typically closed shell. As a result, two vibrationally coupled electronic states depict charge-transfer scenarios whereas three coupled states arise for closed-shell reactions of non-degenerate molecules and seven states for the reactions implicated in the aromaticity of benzene. Previous diabatic treatments of closed-shell processes have considered only two arbitrarily chosen states as being critical, mapping these states to those for electron transfer. We show that such effective two-state diabatic models are feasible but involve renormalized electronic coupling and vibrational coupling parameters, with this renormalization being property dependent. With this caveat, diabatic models are shown to provide excellent descriptions of the spectroscopy and kinetics of the ammonia inversion reaction, proton transfer in N2H7(+), and aromaticity in benzene. This allows for the development of a single simple theory that can semi-quantitatively describe all of these chemical phenomena, as well as of course electron-transfer reactions. It forms a basis for understanding many technologically relevant aspects of chemical reactions, condensed-matter physics, chemical quantum entanglement, nanotechnology, and natural or artificial solar energy capture and conversion.

  8. Redox reactions in food fermentations

    DEFF Research Database (Denmark)

    Hansen, Egon Bech

    2018-01-01

    Food fermentations are typically performed without actively supplying air. Except for possible surface microorganisms, oxygen will only be transiently available and the redox reactions during the fermentation need to be in balance. Production of ATP from fermentation of carbohydrates typically in...... of the redox properties of strains used to compose food cultures.......Food fermentations are typically performed without actively supplying air. Except for possible surface microorganisms, oxygen will only be transiently available and the redox reactions during the fermentation need to be in balance. Production of ATP from fermentation of carbohydrates typically...... involves oxidative steps in the early part of the pathways whereas a multitude of different reactions are used as compensating reductions. Much of the diversity seen between food fermentations arise from the different routes and the different electron acceptors used by microorganisms to counterbalance...

  9. Two Paired "Le Chatelier" Reactions

    Science.gov (United States)

    Cawley, John J.

    1995-07-01

    We have created a two-week, two hour-per-week cyclic experiment, which pairs two reactions. These reactions, the acid catalyzed esterification to yield n-amyl acetate and the base catalyzed hydrolysis of n-amyl acetate are intended to serve as a first and last experiment respectively, of the second-semester laboratory for liberal arts students. Because of time constraints, we have modified these experiments so that no distillation is performed as a purification step. The notion of achieving yields beyond the equilibrium value is discussed in terms of the pragmatics of removing one of the products of an equilibrium. Because of this "Le Chatelier" aspect of each reaction, each of them may be pushed in practicality to completion, which is well beyond the equilibrium value expectation. Because of the cycle, the chemistry may be done on a scale well beyond the microscale approach with little loss of material.

  10. Anaphylactic reactions to novel foods

    DEFF Research Database (Denmark)

    Ballardini, Natalia; Nopp, Anna; Hamsten, Carl

    2017-01-01

    Availability of "exotic" foods is steadily increasing. In this report, we describe the first case of anaphylaxis to crocodile meat. The patient was a 13-year-old boy with severe immunoglobulin E-mediated allergy to chicken meat. When tasting crocodile meat for the first time, he developed...... an anaphylactic reaction. Cross-reactivity between chicken and crocodile meat was suspected to have triggered this reaction. Basophil activation and immunoglobulin E testing confirmed the boy's allergic reaction to crocodile meat proteins. Molecular analysis identified a crocodile a-parvalbumin, with extensive...... sequence homology to chicken a-parvalbumin, as the main cross-reactive allergen. We conclude that crocodile meat can be a potent food allergen and patients with allergy to chicken meat should be advised to avoid intake of meat from crocodile species. Both foods and people travel around the world...

  11. Dynamic effects in fragmentation reactions

    International Nuclear Information System (INIS)

    Bertsch, G. F.; Esbensen, H.

    2002-01-01

    Fragmentation reactions offer a useful tool to study the spectroscopy of halo nuclei, but the large extent of the halo wave function makes the reaction theory more difficult. The simple reaction models based on the eikonal approximation for the nuclear interaction or first-order perturbation theory for the Coulomb interaction have systematic errors that they investigate here, comparing to the predictions of complete dynamical calculations. They find that stripping probabilities are underpredicted by the eikonal model, leading to extracted spectroscopy strengths that are two large. In contrast, the Coulomb excitation is overpredicted by the simple theory. They attribute this to a screening effect, as is well known in the Barkas effect on stopping powers. The errors decrease with beam energy as E(sub beam)(sup -1), and are not significant at beam energies above 50 MeV/u. At lower beam energies, the effects should be taken into account when extracting quantitative spectroscopic strengths

  12. Effective dynamics along given reaction coordinates, and reaction rate theory.

    Science.gov (United States)

    Zhang, Wei; Hartmann, Carsten; Schütte, Christof

    2016-12-22

    In molecular dynamics and related fields one considers dynamical descriptions of complex systems in full (atomic) detail. In order to reduce the overwhelming complexity of realistic systems (high dimension, large timescale spread, limited computational resources) the projection of the full dynamics onto some reaction coordinates is examined in order to extract statistical information like free energies or reaction rates. In this context, the effective dynamics that is induced by the full dynamics on the reaction coordinate space has attracted considerable attention in the literature. In this article, we contribute to this discussion: we first show that if we start with an ergodic diffusion process whose invariant measure is unique then these properties are inherited by the effective dynamics. Then, we give equations for the effective dynamics, discuss whether the dominant timescales and reaction rates inferred from the effective dynamics are accurate approximations of such quantities for the full dynamics, and compare our findings to results from approaches like Mori-Zwanzig, averaging, or homogenization. Finally, by discussing the algorithmic realization of the effective dynamics, we demonstrate that recent algorithmic techniques like the "equation-free" approach and the "heterogeneous multiscale method" can be seen as special cases of our approach.

  13. Miniaturized continuous flow reaction vessels: influence on chemical reactions

    NARCIS (Netherlands)

    Brivio, M.; Verboom, Willem; Reinhoudt, David

    2006-01-01

    This review offers an overview of the relatively young research area of continuous flow lab-on-a-chip for synthetic applications. A short introduction on the basic aspects of lab-on-a-chip is given in the first part. Subsequently, the effects of downscaling reaction vessels as well as the advantages

  14. Reaction rate of propene pyrolysis.

    Science.gov (United States)

    Han, Peipei; Su, Kehe; Liu, Yan; Wang, Yanli; Wang, Xin; Zeng, Qingfeng; Cheng, Laifei; Zhang, Litong

    2011-10-01

    The reaction rate of propene pyrolysis was investigated based on the elementary reactions proposed in Qu et al., J Comput Chem 2009, 31, 1421. The overall reaction rate was developed with the steady-state approximation and the rate constants of the elementary reactions were determined with the variational transition state theory. For the elementary reaction having transition state, the vibrational frequencies of the selected points along the minimum energy path were calculated with density functional theory at B3PW91/6-311G(d,p) level and the energies were improved with the accurate model chemistry method G3(MP2). For the elementary reaction without transition state, the frequencies were calculated with CASSCF/6-311G(d,p) and the energies were refined with the multireference configuration interaction method MRCISD/6-311G(d,p). The rate constants were evaluated within 200-2000 K and the fitted three-parameter expressions were obtained. The results are consistent with those in the literatures in most cases. For the overall rate, it was found that the logarithm of the rate and the reciprocal temperature have excellent linear relationship above 400 K, predicting that the rate follows a typical first-order law at high temperatures of 800-2000 K, which is also consistent with the experiments. The apparent activation energy in 800-2000 K is 317.3 kJ/mol from the potential energy surface of zero Kelvin. This value is comparable with the energy barriers, 365.4 and 403.7 kJ/mol, of the rate control steps. However, the apparent activation energy, 215.7 kJ/mol, developed with the Gibbs free energy surface at 1200 K is consistent with the most recent experimental result 201.9 ± 0.6 kJ/mol. Copyright © 2011 Wiley Periodicals, Inc.

  15. Clozapine-associated extrapyramidal reaction.

    Science.gov (United States)

    Elliott, E S; Marken, P A; Ruehter, V L

    2000-05-01

    To report a case of extrapyramidal reaction associated with a dosage increase of clozapine. A 44-year-old white man with a 20-year history of chronic paranoid schizophrenia was admitted to an inpatient psychiatric facility. His prior medications restarted on admission were clozapine 650 mg at bedtime, haloperidol 10 mg at bedtime, clonazepam 2 mg/d, and aspirin 325 mg/d. Two days after admission (hospital day 3), clozapine and clonazepam were discontinued, and he was prescribed haloperidol 5 mg every morning and 10 mg every evening. Stabilization occurred over the following 24 days, with progressively lower dosages of haloperidol and increasing dosages of clozapine. Haloperidol was discontinued on day 24. On day 47, the patient was agitated and making bizarre statements; thus, the morning dose of clozapine was increased by 50 mg (total 450 mg/d). On day 48 at 2200, a dystonic reaction was diagnosed; he received intramuscular diphenhydramine 50 mg, which caused the reaction to subside. At the time of the adverse reaction, he was prescribed clozapine 450 mg/d, vitamin E 400 IU three times daily, aspirin 325 mg/d, and acetaminophen, milk of magnesia, and Maalox as needed. Although the risk of extrapyramidal symptoms (EPS) is significantly lower with clozapine than with conventional agents, elevated clozapine blood concentrations have been reported to cause EPS; other reports have cited severe dystonias and dyskinesias on abrupt clozapine withdrawal. Considering the medications prescribed at the time and the discontinuation of haloperidol 24 days before the event, clozapine was the most likely cause of the extrapyramidal reaction. Regardless of anticipated safety associated with novel antipsychotics such as clozapine, reports of dystonic reactions must be taken into account and patients monitored appropriately.

  16. Allergic reactions occurring during anaesthesia.

    Science.gov (United States)

    Mertes, P M; Laxenaire, M C

    2002-04-01

    Anaphylactic reactions to anaesthetic and associated agents used during the perioperative period have been reported with increasing frequency in most developed countries. Any drug administered in the perioperative period can potentially produce life-threatening immune-mediated anaphylaxis. Most published reports on the incidence of anaphylaxis come from France, Australia, the UK and New Zealand. These reflect an active policy of systematic clinical and/or laboratory investigation of suspected immune-mediated reactions. The estimated incidence of anaphylaxis ranges from 1:10,000 to 1:20,000. Muscle relaxants (69.1%) and latex (12.1%) were the most frequently involved drugs according to the most recent French epidemiological survey. Clinical symptoms do not afford an easy distinction between immune-mediated anaphylactic reactions and anaphylactoid reactions resulting from direct non-specific histamine release. Moreover, when restricted to a single clinical symptom, anaphylaxis can easily be misdiagnosed. Pre- and postoperative investigation must be performed to confirm the nature of the reaction, the responsibility of the suspected drugs and to provide precise recommendations for future anaesthetic procedures. These include plasma histamine, tryptase and specific IgE concentration determination at the time of the reaction and at skin tests 6 weeks later. In addition, since no specific treatment has been shown reliably to prevent the occurrence of anaphylaxis, allergy assessment must be performed in all high-risk patients. Treatment of anaphylaxis is aimed at interrupting contact with the responsible antigen, inhibiting mediator production and release, and modulating the effects of released mediators. It must be initiated as quickly as possible and relies on widely accepted principles. Finally, the need for proper epidemiological studies and the relative complexity of allergy investigation should be underscored. They represent an incentive for further development of

  17. Internal friction in enzyme reactions.

    Science.gov (United States)

    Rauscher, Anna; Derényi, Imre; Gráf, László; Málnási-Csizmadia, András

    2013-01-01

    The empirical concept of internal friction was introduced 20 years ago. This review summarizes the results of experimental and theoretical studies that help to uncover the nature of internal friction. After the history of the concept, we describe the experimental challenges in measuring and interpreting internal friction based on the viscosity dependence of enzyme reactions. We also present speculations about the structural background of this viscosity dependence. Finally, some models about the relationship between the energy landscape and internal friction are outlined. Alternative concepts regarding the viscosity dependence of enzyme reactions are also discussed. Copyright © 2012 International Union of Biochemistry and Molecular Biology, Inc.

  18. Vision 2020. Reaction Engineering Roadmap

    Energy Technology Data Exchange (ETDEWEB)

    Klipstein, David H. [Reaction Design, San Diego, CA (United States); Robinson, Sharon [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2001-01-01

    The Reaction Engineering Roadmap is a part of an industry- wide effort to create a blueprint of the research and technology milestones that are necessary to achieve longterm industry goals. This report documents the results of a workshop focused on the research needs, technology barriers, and priorities of the chemical industry as they relate to reaction engineering viewed first by industrial use (basic chemicals; specialty chemicals; pharmaceuticals; and polymers) and then by technology segment (reactor system selection, design, and scale-up; chemical mechanism development and property estimation; dealing with catalysis; and new, nonstandard reactor types).

  19. Dynamics of traveling reaction pulses

    International Nuclear Information System (INIS)

    Dovzhenko, A. Yu.; Rumanov, E. N.

    2007-01-01

    The growth of activator losses is accompanied by the decay of a traveling reaction pulse. In a ring reactor, this propagation threshold is present simultaneously with a threshold related to the ring diameter. The results of numerical experiments with pulses of an exothermal reaction reveal the transition from pulse propagation to a homogeneous hot regime, established regimes with periodic variations of the pulse velocity, and oscillatory decay of the pulse. When the medium becomes 'bistable' as a result of the variation in parameters, this factor does not prevent the propagation of pulses, but leads to changes in the pulse structure

  20. Reaction

    African Journals Online (AJOL)

    raoul

    12 janv. 2012 ... Key words: Métastase, rate, colon, carcinome. Received: 28/12/2011 - Accepted: 09/01/2012 - Published: ... tomodensitométriques au moment du diagnostic du cancer primitif ou lors du suivi radiologique régulier des patients atteints de cancers. Le recours à la TEP-FDG couplée au scanner serait d'un ...

  1. Reaction

    African Journals Online (AJOL)

    abp

    19 oct. 2017 ... Axillary block is an easy and recommended technique in children. Its use in children with acute hepatitis A is not risk free especially when associated with sedation using remifentanil and propofol. Similarly, the presence of a single hydatid cyst allows general anesthesia with mono- pulmonary ventilation.

  2. Reaction

    African Journals Online (AJOL)

    abp

    2013-03-05

    Mar 5, 2013 ... define direct costs to include the out-of pocket (monetary) expenditures such as payments for ... elevated blood pressure is more of the late middle age and elderly group. It also suggests that at this age they ... definition, the study showed that about 53% of the household of the patients incurred catastrophic ...

  3. Palladium-Catalysed Coupling Reactions

    NARCIS (Netherlands)

    de Vries, Johannes G.; Beller, M; Blaser, HU

    2012-01-01

    Palladium-catalysed coupling reactions have gained importance as a tool for the production of pharmaceutical intermediates and to a lesser extent also for the production of agrochemicals, flavours and fragrances, and monomers for polymers. In this review only these cases are discussed where it seems

  4. The Pitfalls of Precipitation Reactions.

    Science.gov (United States)

    Slade, Peter W.; Rayner-Canham, Geoffrey W.

    1990-01-01

    Described are some of the difficulties presented in these reactions by competing equilibria that are usually ignored. Situations involving acid-base equilibria, solubility product calculations, the use of ammonia as a complexing agent, and semiquantitative comparisons of solubility product values are discussed. (CW)

  5. Engineering reactors for catalytic reactions

    Indian Academy of Sciences (India)

    ... improvements in reactor performance. In this article, application of recent (and not so recent) developments in engineering reactors for catalytic reactions is discussed. Some examples where performance enhancement was realized by catalyst design, appropriate choice of reactor, better injection and dispersion strategies ...

  6. Apparent tunneling in chemical reactions

    DEFF Research Database (Denmark)

    Henriksen, Niels Engholm; Hansen, Flemming Yssing; Billing, G. D.

    2000-01-01

    A necessary condition for tunneling in a chemical reaction is that the probability of crossing a barrier is non-zero, when the energy of the reactants is below the potential energy of the barrier. Due to the non-classical nature (i.e, momentum uncertainty) of vibrational states this is, however...

  7. Reactions of ethanol on Ru

    NARCIS (Netherlands)

    Sturm, Jacobus Marinus; Liu, Feng; Lee, Christopher James; Bijkerk, Frederik

    2012-01-01

    The adsorption and reactions of ethanol on Ru(0001) were studied with temperatureprogrammed desorption (TPD) and reflection-absorption infrared spectroscopy (RAIRS). Ethanol was found to adsorb intact onto Ru(0001) below 100 K. Heating to 250 K resulted in formation of ethoxy groups, which undergo

  8. Engineering reactors for catalytic reactions

    Indian Academy of Sciences (India)

    on selectivity can make substantial impact on process viability and economics. Extensive studies have been conducted to establish sound basis for design and engineering of reactors for practising such catalytic reactions and for realizing improvements in reactor performance. In this article, application of recent (and not so ...

  9. Engineering reactors for catalytic reactions

    Indian Academy of Sciences (India)

    cation strategies for effective translation of laboratory process to practise. ... control). Several tools for modelling of chemical kinetics and reactions are already well-developed and routinely used in practice for facilitating engineering of reactors. Sev- eral excellent ... in absence of catalyst and is often controlled by mix-.

  10. Organic Reaction Mechanism Controversy: Pedagogical ...

    African Journals Online (AJOL)

    The paper investigated the pedagogical implications of the controversy generated by the nature of reaction mechanism in organic chemistry as to whether it can be proven or not. A conference of a chemist, chemical educator, a graduate chemistry teacher and a graduate assistant was organized. The conference lasted for ...

  11. Reaction rates when barriers fluctuate

    OpenAIRE

    Reimann, Peter

    1999-01-01

    Reaction rates when barriers fluctuate : a path integral approach / P. Hänggi and P. Reimann. - In: International Conference on Path Integrals from peV to TeV : Proceedings of the ... / eds.: R. Casalbuoni ... - Singapore u.a. : World Scientific, 1999. - S. 407-409

  12. Reduction of chemical reaction models

    Science.gov (United States)

    Frenklach, Michael

    1991-01-01

    An attempt is made to reconcile the different terminologies pertaining to reduction of chemical reaction models. The approaches considered include global modeling, response modeling, detailed reduction, chemical lumping, and statistical lumping. The advantages and drawbacks of each of these methods are pointed out.

  13. Reactants encapsulation and Maillard Reaction

    NARCIS (Netherlands)

    Troise, A.D.; Fogliano, V.

    2013-01-01

    In the last decades many efforts have been addressed to the control of Maillard Reaction products in different foods with the aim to promote the formation of compounds having the desired color and flavor and to reduce the concentration of several potential toxic molecules. Encapsulation, already

  14. Humanism and science: a reaction.

    Science.gov (United States)

    Wampold, Bruce E

    2012-12-01

    Authors in this section have noted that humanism is intrinsic to psychotherapy, although disagreements remain. One of the disagreements is about the role of science in humanism. In this reaction, I contend that humanism, as discussed in these articles, is a legitimate theory to be subjected to scientific scrutiny. (c) 2012 APA, all rights reserved.

  15. Immediate hypersensitivity reactions to corticosteroids.

    Science.gov (United States)

    Patel, Adesh; Bahna, Sami L

    2015-09-01

    To review the literature on immediate hypersensitivity reactions to corticosteroids and classify them according to manifestations, routes of exposure, causative preparations, diagnostic tests, and management. PubMed search for English-language publications from January 1, 2004 through December 31, 2014 using search terms corticosteroid, glucocorticoid, or steroid combined with hypersensitivity, allergy, or anaphylaxis. Only reports of immediate hypersensitivity reactions that occurred sooner than 24 hours after administration of a corticosteroid were included. Excluded were reports on patients with delayed reactions, including contact dermatitis. Forty-eight articles fulfilled the criteria, reporting 120 reactions in 106 patients 2 to 90 years of age (55 male and 51 female). The most commonly reported manifestation was anaphylaxis in 60.8% (73 of 120) followed by urticaria and/or angioedema in 26.7%. Exposure to corticosteroid was through any route, with intravenous being the most common (44.2%, 53 of 120), followed by oral in 25.8% and intra-articular in 11.7%. Methylprednisolone was the most commonly implicated (40.8%) followed by prednisolone (20.0%). Some reacted to more than 1 preparation. Pharmacologically-inactive ingredients were implicated in 28.3%. Diagnosis was based primarily on medical history and in most cases was confirmed by challenge testing. Skin tests were positive in 74.1%. The vast majority of patients tolerated at least 1 alternative preparation, and very rarely desensitization was required. Corticosteroids seem to be rare causes of immediate hypersensitivity reactions but possibly are misdiagnosed or under-reported relative to their worldwide use. Physicians should be cognizant of this entity and identify safe alternative preparations. Copyright © 2015 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  16. KINETICS AND MECHANISM OF REACTION OF ACIDIC ...

    African Journals Online (AJOL)

    For both Nile blue and Meldola\\'s blue reactions the rates have first-order dependence on each substrate, chlorite and acid. Both reactions showed negative salt effect indicating the reaction is between the oppositely charged species, likely the substrate cation and chlorite anion. The acidic chlorite reaction with MB+ was ...

  17. Use of Isotopes for Studying Reaction Mechanisms

    Indian Academy of Sciences (India)

    would help us optimize reaction conditions to effect higher yields, minimize reaction times, etc. The transformation ... effect of the isotope on the reaction rate. In the following. Uday Maitra and. J Chandrasekhar .... to the reaction, the rate of isotope exchange was unaltered, but the rate of racemization (of the reactant) became ...

  18. Reaction of hydrogen atoms with acrylaldehyde

    International Nuclear Information System (INIS)

    Koda, Seiichiro; Nakamura, Kazumoto; Hoshino, Takashi; Hikita, Tsutomu

    1978-01-01

    The reaction of hydrogen atoms with acrylaldehyde was investigated in a fast flow reactor equipped with a time-of-flight type mass spectrometer under reduced pressure. Main reaction products were carbon monoxide, ethylene, ethane, methane, and propanal. Consideration of the distributions of the reaction products under various reaction conditions showed that hydrogen atoms attacked the C=C double bond, especially its inner carbon side under reduced pressure. Resulting hot radicals caused subsequent reactions. The relative value of the apparent bimolecular rate constant of the reaction against that of trans-2-butene with hydrogen atoms was 1.6+-0.2, which supported the above-mentioned initial reaction. (auth.)

  19. Optimizing Chemical Reactions with Deep Reinforcement Learning.

    Science.gov (United States)

    Zhou, Zhenpeng; Li, Xiaocheng; Zare, Richard N

    2017-12-27

    Deep reinforcement learning was employed to optimize chemical reactions. Our model iteratively records the results of a chemical reaction and chooses new experimental conditions to improve the reaction outcome. This model outperformed a state-of-the-art blackbox optimization algorithm by using 71% fewer steps on both simulations and real reactions. Furthermore, we introduced an efficient exploration strategy by drawing the reaction conditions from certain probability distributions, which resulted in an improvement on regret from 0.062 to 0.039 compared with a deterministic policy. Combining the efficient exploration policy with accelerated microdroplet reactions, optimal reaction conditions were determined in 30 min for the four reactions considered, and a better understanding of the factors that control microdroplet reactions was reached. Moreover, our model showed a better performance after training on reactions with similar or even dissimilar underlying mechanisms, which demonstrates its learning ability.

  20. Resonance phenomena in few-body reactions

    International Nuclear Information System (INIS)

    Micek, S.

    1976-01-01

    In this work resonant states observed in two-body (p,p) reactions are compared. Theoretical analysis gives agreement in the resonant parameters in both types of the reactions for 41 Sc and 59 Cu nuclei. The excitation of states with higher angular momenta in the three-body reactions allows one to use this reaction as an supplementary to the two-body reaction in the investigations of resonant states. (author)

  1. Reaction engineering of urea alcoholysis: Alkyl carbamates

    OpenAIRE

    Mote, Dhananjay R.; Ranade, Vivek V.

    2017-01-01

    Urea alcoholysis is a reversible reaction generating alkyl carbamate and ammonia as products. The reaction can be performed non-catalytically or in presence of catalyst. The first step in Reaction engineering analysis is to finalize the reactor configuration. In this case it is important to determine the necessity of reactive separation (simultaneous reaction and separation). This has been addressed by first establishing the reversibility of the reaction through theoretical and experimental i...

  2. Thermodynamics of Enzyme-Catalyzed Reactions Database

    Science.gov (United States)

    SRD 74 Thermodynamics of Enzyme-Catalyzed Reactions Database (Web, free access)   The Thermodynamics of Enzyme-Catalyzed Reactions Database contains thermodynamic data on enzyme-catalyzed reactions that have been recently published in the Journal of Physical and Chemical Reference Data (JPCRD). For each reaction the following information is provided: the reference for the data, the reaction studied, the name of the enzyme used and its Enzyme Commission number, the method of measurement, the data and an evaluation thereof.

  3. Multiresponse modelling of the caramelisation reaction

    OpenAIRE

    Quintas, Mafalda; Guimarães, Carla; Baylina, João; Brandão, Teresa R. S.; Silva, Cristina L.M.

    2007-01-01

    Multiresponse modelling is a powerful tool for studying complex kinetics of reactions occurring in food products. This modelling technique uses information of reactants and products involved, allowing insightful kinetic parameters estimation and helping in clarifying reaction mechanisms. One example of a complex reaction that occurs in food processing is the caramelisation reaction. Caramelisation is the common name for a group of reactions observed when carbohydrates are exposed to high temp...

  4. Limits for Stochastic Reaction Networks

    DEFF Research Database (Denmark)

    Cappelletti, Daniele

    at a certain time are stochastically modelled by means of a continuous-time Markov chain. Our work concerns primarily stochastic reaction systems, and their asymptotic properties. In Paper I, we consider a reaction system with intermediate species, i.e. species that are produced and fast degraded along a path...... network tends to that of the original one. In particular, we prove a uniform punctual convergence in distribution and weak convergence of the integrals of continuous functions along the paths of the two models. Under some extra conditions, we also prove weak convergence of the two processes. The result....... Such species, in the deterministic modelling regime, assume always the same value at any positive steady state. In the stochastic setting, we prove that, if the initial condition is a point in the basin of attraction of a positive steady state of the corresponding deterministic model and tends to innity...

  5. MEANS FOR TERMINATING NUCLEAR REACTIONS

    Science.gov (United States)

    Cooper, C.M.

    1959-02-17

    An apparatus is presented for use in a reactor of the heterogeneous, fluid cooled type for the purpose of quickly terminating the reaction, the coolant being circulated through coolant tubes extending through the reactor core. Several of the tubes in the critical region are connected through valves to a tank containing a poisoning fluid having a high neutron capture crosssection and to a reservoir. When it is desired to quickly terminate the reaction, the valves are operated to permit the flow of the poisoning fluid through these particular tubes and into the reservoir while normal coolant is being circulated through the remaining tubes. The apparatus is designed to prevent contamination of the primary coolant by the poisoning fluid.

  6. Theoretical aspects of surface reactions

    Science.gov (United States)

    Nørskov, J. K.; Stoltze, P.

    1987-10-01

    A short review is given of our present understanding of the trends in the chemisorption energies and activation energies for dissociation of simple gas molecules on the transition metals. The effect of adsorbed alkali atoms on the activation energy for dissociation is also discussed. This is then used to explain the trends in activity along the transition metal rows and the promoting effect of K for the ammonia synthesis reaction. The basis for the description is the development of a kinetic model for the ammonia synthesis which can describe quantitatively the macroscopic kinetics of a commercial catalyst under industrial conditions. The model relates the reaction rate directly to the properties of the chemisorbed reactants, intermediates and product as measured for model single crystal systems under ultrahigh vacuum conditions.

  7. Electrochemical promotion of catalytic reactions

    Science.gov (United States)

    Imbihl, R.

    2010-05-01

    The electrochemical promotion of heterogeneously catalyzed reactions (EPOC) became feasible through the use of porous metal electrodes interfaced to a solid electrolyte. With the O 2- conducting yttrium stabilized zirconia (YSZ), the Na + conducting β″-Al 2O 3 (β-alumina), and several other types of solid electrolytes the EPOC effect has been demonstrated for about 100 reaction systems in studies conducted mainly in the mbar range. Surface science investigations showed that the physical basis for the EPOC effect lies in the electrochemically induced spillover of oxygen and alkali metal, respectively, onto the surface of the metal electrodes. For the catalytic promotion effect general concepts and mechanistic schemes were proposed but these concepts and schemes are largely speculative. Applying surface analytical tools to EPOC systems the proposed mechanistic schemes can be verified or invalidated. This report summarizes the progress which has been achieved in the mechanistic understanding of the EPOC effect.

  8. Allergic reactions in red tattoos

    DEFF Research Database (Denmark)

    Hutton Carlsen, K; Køcks, M; Sepehri, M

    2016-01-01

    AIM: The aim of this study was to assess the feasibility of Raman spectroscopy as a screening technique for chemical characterisation of tattoo pigments in pathologic reacting tattoos and tattoo ink stock products to depict unsafe pigments and metabolites of pigments. MATERIALS/METHODS: Twelve...... to be feasible for chemical analysis of red pigments in allergic reactions. Raman spectroscopy has a major potential for fingerprint screening of problematic tattoo pigments in situ in skin, ex vivo in skin biopsies and in tattoo ink stock products, thus, to eliminate unsafe ink products from markets....... dermatome shave biopsies from allergic reactions in red tattoos were analysed with Raman spectroscopy (A 785-nm 300 mW diode laser). These were referenced to samples of 10 different standard tattoo ink stock products, three of these identified as the culprit inks used by the tattooist and thus by history...

  9. Vanadocene reactions with hydroxy acids

    International Nuclear Information System (INIS)

    Latyaeva, V.N.; Lineva, A.N.; Zimina, S.V.; Ehllert, O.G.; Arsen'eva, T.I.

    1984-01-01

    To prepare a series of vanadium cyclopentadienylcarboxylates soluble in water, the vanadocene reactions with lactic, γ-oxybutyric-, salicylic,- gallic-, orotic-, and acetylsalicylic acids have been studied. To determine the influence of cyclopentadienyl groups, bound with a vanadium atom, on the physiological activity of the complexes formed, vanadium halides are made to react with lactic acid. Only the vanadocene reaction with orotic acid was conducted in an aqueous medium, other interactions were realized in the diethyl ether, toluene, T, H, P medium. The interaction of vanadocene and vanadium halides with lactic-, salicylic-, acetylsalicylic- and gallic acids was found to lead to the formation of water-soluble vanadium complexes of Cp 2 , VOCOR or CpV (OCOR) 2 type. The data on the produced compounds yield, their IR spectra, decomposition temperatures, solubility, effective magnetic moments are presented

  10. Statistical theory of breakup reactions

    Energy Technology Data Exchange (ETDEWEB)

    Bertulani, Carlos A., E-mail: carlos.bertulani@tamuc.edu [Department of Physics and Astronomy, Texas A and M University-Commerce, Commerce, TX (United States); Descouvemont, Pierre, E-mail: pdesc@ulb.ac.be [Physique Nucleaire Theorique et Physique Mathematique, Universite Libre de Bruxelles (ULB), Brussels (Belgium); Hussein, Mahir S., E-mail: hussein@if.usp.br [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil). Instituto de Estudos Avancados

    2014-07-01

    We propose an alternative for Coupled-Channels calculations with loosely bound exotic nuclei (CDCC), based on the the Random Matrix Model of the statistical theory of nuclear reactions. The coupled channels equations are divided into two sets. The first set, described by the CDCC, and the other set treated with RMT. The resulting theory is a Statistical CDCC (CDCC{sub s}), able in principle to take into account many pseudo channels. (author)

  11. Stickland reactions of dental plaque.

    Science.gov (United States)

    Curtis, M A; Kemp, C W; Robrish, S A; Bowen, W H

    1983-01-01

    Dental plaque samples from monkeys (Macaca fascicularis) were shown to contain proline reduction activity in coupled Stickland reactions with other amino acids and also with certain end products of bacterial glucose metabolism. The unusually high concentration of bound and free proline in the oral environment may be of importance in both the production of base and in the removal of acid from the tooth surface after dietary carbohydrate ingestion. PMID:6618673

  12. Anaphylactic reaction after artificial insemination.

    Science.gov (United States)

    Orta, Marta; Ordoqui, Elena; Aranzábal, Ascensión; Fernández, Cristina; Bartolomé, Borja; Sanz, Maria Luisa

    2003-04-01

    Bovine seroalbumin is known as an allergen for human beings, but reactions to it in an artificial insemination procedure are much rarer. We report a case of anaphylaxis after intrauterine insemination (IUI) in which sensitization to bovine serum albumin (BSA) is demonstrated. Report the allergy evaluation performed in a patient who suffered a severe reaction immediately after an IUI procedure. A 33-year-old woman was referred because of an anaphylactic reaction after a second trial of IUI. She developed pruritus, abdominal pain, nausea and vomiting, bronchospasm, and generalized urticaria. She had an atopic medical history of pollen allergy and sensitization to cat epithelium. She had never had trouble with minor surgery and she usually uses latex material. She had never received heterologous sera before. Her husband's semen for the IUI was processed in a standard fluid medium called upgraded INRA B 2 (Laboratoires CCD, Paris, France), which contains amino acids, lipids, vitamins, BSA, penicillin, and streptomycin in addition to inorganic salts. Skin prick tests with the medium and BSA 10 mg/mL were positive. In vitro studies demonstrated an immunoglobulin E binding protein of 60 to 65 kDa and mast cells and basophil activation (CD63 expression) against BSA contained in the medium. Cutaneous and challenge tests with penicillin and streptomycin were negative. We consider the BSA in the semen culture medium to be the factor which triggered the anaphylactic reaction. This case supports the authors who state that media free from heterologous proteins should be used for human application, especially on atopic patients, to avoid sensitization.

  13. When the chain reaction started

    International Nuclear Information System (INIS)

    1968-01-01

    It was 2 December 1942. Just as the band of distinguished scientists were waiting for the world's first chain reaction to start in the first atomic pile Enrico Fermi looked at his watch and said 'Gentlemen, time for lunch'. This incident was part of the first-hand story related to members of the Agency staff on 3 September this year by Professor Herbert L. Anderson of Chicago University, one of the team engaged in the project. (author)

  14. Tuberculin reaction and BCG scar

    DEFF Research Database (Denmark)

    Timmermann, Clara Amalie Gade; Biering-Sørensen, Sofie; Aaby, Peter

    2015-01-01

    rate ratio (MRR) comparing children with a BCG scar with those without was 0.42 (95% CI = 0.19; 0.93). There was a similar tendency for TST positivity: MRR = 0.47 (95% CI = 0.14; 1.54). For LBW children who had both a positive TST reaction and a scar, the MRR was 0.22 (95% CI = 0.05; 0.87). For NBW...

  15. Statistical theory of breakup reactions

    International Nuclear Information System (INIS)

    Bertulani, Carlos A.; Descouvemont, Pierre; Hussein, Mahir S.

    2014-01-01

    We propose an alternative for Coupled-Channels calculations with loosely bound exotic nuclei (CDCC), based on the the Random Matrix Model of the statistical theory of nuclear reactions. The coupled channels equations are divided into two sets. The first set, described by the CDCC, and the other set treated with RMT. The resulting theory is a Statistical CDCC (CDCC s ), able in principle to take into account many pseudo channels. (author)

  16. Anaphylactoid Reaction Against to Atropine

    Directory of Open Access Journals (Sweden)

    Melike Korkmaz Toker

    2014-08-01

    Full Text Available In this case report, the anaphylactoid reaction against to atropine had been reported in a 51 years old woman patient who had undertaken to total abdominal hystrectomy and bilateral salphingooferectomy surgery. At the end of the surgery, the anesthesia maintenance finished during the extubation procedure consequtively atropine had given intravenously 0,01 mg.kg-1 for preventing the neostigmine’s cholinergic effects. After the enjection of atropine tachycardia occured, nonpitting edema, maculopapular skin rash beginning from the periferal veins especially head and neck region spread out althrough the body observed. Anaphylactoid reaction developing like angioedema at the head and neck region threated the airway safety, therefore methylprednisolone 4 mg.kg-1, ranitidine 50 mg and feniramine maleat 1 mg.kg-1 intravenously administered. For safety of the airway the patient transferred to intensive care unit as intubated. After 24 hours follow up patient had clinically recovered and extubated. With our case report we try to emphasise the anaphylactoid reaction against to atropine and raise awareness of the anesthesiologists.

  17. Modulation of spermatozoon acrosome reaction

    Directory of Open Access Journals (Sweden)

    Pilar Vigil

    2011-01-01

    Full Text Available Spermatozoon acrosome reaction is an exocytotic event of the utmost importance for the development of mammalian fertilisation. Current evidence shows that the triggering of the acrosome reaction (AR could be regulated by the action of diverse compounds, namely, metabolites, neurotransmitters and hormones. The aim of the present review is to describe the modulating effects of several compounds that have been classified as inductors or inhibitors of acrosome reaction. Among AR inductors, it is necessary to mention progesterone, angiotensin II, atrial natriuretic peptide, cathecolamines, insulin, leptin, relaxin and other hormones. Regarding the inhibitors, oestradiol and epidermal growth factor are among the substances that retard AR. It is worth mentioning that gamma-aminobutyric acid, a neurotransmitter known to be an inhibitor in the central nervous system, has been shown to induce AR. The multiple hormones located in the fluids of the female reproductive tract are also likely to act as subtle regulators of AR, constituting a fundamental aspect for the development of successful fertilisation. Finally, it is necessary to emphasise that the study of regulation exerted by hormones and other compounds on AR is essential for further understanding of mammalian reproductive biology, especially spermatozoon physiology.

  18. Microfabricated electrochemiluminescence cell for chemical reaction detection

    Science.gov (United States)

    Northrup, M. Allen; Hsueh, Yun-Tai; Smith, Rosemary L.

    2003-01-01

    A detector cell for a silicon-based or non-silicon-based sleeve type chemical reaction chamber that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The detector cell is an electrochemiluminescence cell constructed of layers of silicon with a cover layer of glass, with spaced electrodes located intermediate various layers forming the cell. The cell includes a cavity formed therein and fluid inlets for directing reaction fluid therein. The reaction chamber and detector cell may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The ECL cell may also be used in synthesis instruments, particularly those for DNA amplification and synthesis.

  19. Chlorination of Amino Acids: Reaction Pathways and Reaction Rates.

    Science.gov (United States)

    How, Zuo Tong; Linge, Kathryn L; Busetti, Francesco; Joll, Cynthia A

    2017-05-02

    Chlorination of amino acids can result in the formation of organic monochloramines or organic dichloramines, depending on the chlorine to amino acid ratio (Cl:AA). After formation, organic chloramines degrade into aldehydes, nitriles and N-chloraldimines. In this paper, the formation of organic chloramines from chlorination of lysine, tyrosine and valine were investigated. Chlorination of tyrosine and lysine demonstrated that the presence of a reactive secondary group can increase the Cl:AA ratio required for the formation of N,N-dichloramines, and potentially alter the reaction pathways between chlorine and amino acids, resulting in the formation of unexpected byproducts. In a detailed investigation, we report rate constants for all reactions in the chlorination of valine, for the first time, using experimental results and modeling. At Cl:AA = 2.8, the chlorine was found to first react quickly with valine (5.4 × 10 4 M -1 s -1 ) to form N-monochlorovaline, with a slower subsequent reaction with N-monochlorovaline to form N,N-dichlorovaline (4.9 × 10 2 M -1 s -1 ), although some N-monochlorovaline degraded into isobutyraldehyde (1.0 × 10 -4 s -1 ). The N,N-dichlorovaline then competitively degraded into isobutyronitrile (1.3 × 10 -4 s -1 ) and N-chloroisobutyraldimine (1.2 × 10 -4 s -1 ). In conventional drinking water disinfection, N-chloroisobutyraldimine can potentially be formed in concentrations higher than its odor threshold concentration, resulting in aesthetic challenges and an unknown health risk.

  20. Chemical reactions in solvents and melts

    CERN Document Server

    Charlot, G

    1969-01-01

    Chemical Reactions in Solvents and Melts discusses the use of organic and inorganic compounds as well as of melts as solvents. This book examines the applications in organic and inorganic chemistry as well as in electrochemistry. Organized into two parts encompassing 15 chapters, this book begins with an overview of the general properties and the different types of reactions, including acid-base reactions, complex formation reactions, and oxidation-reduction reactions. This text then describes the properties of inert and active solvents. Other chapters consider the proton transfer reactions in

  1. [Reactions to insect stings and bites].

    Science.gov (United States)

    Ljubojević, Suzana; Lipozencić, Jasna

    2011-01-01

    Reaction to insect sting and bite may be local, such as erythema, edema and pruritus, or systemic, such as anaphylactic reaction. Diagnosis can be made by patient history, clinical picture, skin testing, total and specific IgE level, and provocation test. Local reactions are treated with cold compresses, topical corticosteroids and oral antihistamines. Oral and intramuscular antihistamines and corticosteroids are used for the treatment of mild systemic reactions, and in severe reaction epinephrine injections are added. Hyposensitization is indicated in patients with severe systemic reaction, positive skin tests and high level of specific IgE antibodies.

  2. Metal-catalyzed asymmetric aldol reactions

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Luiz C.; Lucca Junior, Emilio C. de; Ferreira, Marco A. B.; Polo, Ellen C., E-mail: ldias@iqm.unicamp.br [Universidade de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica

    2012-12-15

    The aldol reaction is one of the most powerful and versatile methods for the construction of C-C bonds. Traditionally, this reaction was developed in a stoichiometric version; however, great efforts in the development of chiral catalysts for aldol reactions were performed in recent years. Thus, in this review article, the development of metal-mediated chiral catalysts in Mukaiyama-type aldol reaction, reductive aldol reaction and direct aldol reaction are discussed. Moreover, the application of these catalysts in the total synthesis of complex molecules is discussed. (author)

  3. Substrate-Directed Catalytic Selective Chemical Reactions.

    Science.gov (United States)

    Sawano, Takahiro; Yamamoto, Hisashi

    2018-03-06

    The development of highly efficient reactions at only the desired position is one of the most important subjects in organic chemistry. Most of the reactions in current organic chemistry are reagent- or catalyst-controlled reactions, and the regio- and stereoselectivity of the reactions are determined by the inherent nature of the reagent or catalyst. In sharp contrast, substrate-directed reaction determines the selectivity of the reactions by the functional group on the substrate and can strictly distinguish sterically and electronically similar multiple reaction sites in the substrate. In this Perspective, three topics of substrate-directed reaction are mainly reviewed: (1) directing group-assisted epoxidation of alkenes, (2) ring-opening reactions of epoxides by various nucleophiles, and (3) catalytic peptide synthesis. Our newly developed synthetic methods with new ligands including hydroxamic acid derived ligands realized not only highly efficient reactions but also pinpointed reactions at the expected position, demonstrating the substrate-directed reaction as a powerful method to achieve the desired regio- and stereoselective functionalization of molecules from different viewpoints of reagent- or catalyst-controlled reactions.

  4. Microfabricated sleeve devices for chemical reactions

    Science.gov (United States)

    Northrup, M. Allen

    2003-01-01

    A silicon-based sleeve type chemical reaction chamber that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The reaction chamber combines a critical ratio of silicon and non-silicon based materials to provide the thermal properties desired. For example, the chamber may combine a critical ratio of silicon and silicon nitride to the volume of material to be heated (e.g., a liquid) in order to provide uniform heating, yet low power requirements. The reaction chamber will also allow the introduction of a secondary tube (e.g., plastic) into the reaction sleeve that contains the reaction mixture thereby alleviating any potential materials incompatibility issues. The reaction chamber may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The reaction chamber may also be used in synthesis instruments, particularly those for DNA amplification and synthesis.

  5. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2000-01-01

    Full text: During last year the physicists of the Department of Nuclear Reactions were involved in many experiments and projects: -Low energy nuclear reactions: For the first time a heavy ion beam from the Warsaw Cyclotron C-200 was used to investigate elastic and inelastic scattering of 12 C ions from 12 C target. The experiment is a part of a long range programme devoted to study the energy dependence of the nucleus-nucleus interactions. -Multifragmentation of relativistic heavy ions: Multifragmentation reactions induced by 12 C on different heavy targets and at different energies were studied in experiments performed at Gesellschaft fuer Schwerionenforschung by the ALADIN Collaboration. These asymmetric systems were investigated in order to study the interplay between preequilibrium and equilibrium phenomena in the nuclear liquid - gas phase transition. -The structure of nucleons: A novel, two-structure description of the Roper resonance was proposed on the basis of the α-p scattering data reanalysed by means of a T-matrix formalism. -Atomic physics: Emission of the X-rays by fast heavy ions (S, Ti, Fe) as they traverse the matter (thin carbon or other light element foil) was investigated in a series of experiments performed at University of Erlangen. It was demonstrated, that the characteristic K α X-rays emitted by a heavy ion can serve as a tool for Z-value control of the ion. -Material research: Semiconductor heterostructures were investigated by means of Rutherford Back Scattering and Channeling methods using the 2 MeV α particles from the Van de Graaff accelerator ''Lech'' at the Department. The following reports present the results and major successes which were achieved in 1999. (author)

  6. Neutral currents in semileptonic reactions

    International Nuclear Information System (INIS)

    Paschos, E.A.

    1975-05-01

    The evidence for weak neutral currents is analyzed in semileptonic reactions with special emphasis on their Lorentz and internal symmetry structure. It is found that present observations are consistent with the expectations of gauge theories, but other possibilities can not be ruled out. Of particular interest in this respect is the presence of a large isoscalar component. The excitation of the Δ-resonance by neutral currents is analyzed, and pion-nucleon mass distributions are presented. Charge asymmetries sensitive to isoscalar-isovector interferences are discussed. (U.S.)

  7. The first nuclear chain reaction

    International Nuclear Information System (INIS)

    Zinn, W.H.

    1989-01-01

    The author offers his recollections of the experimental efforts beginning in 1939 which culminated in the Chain Reaction in the squash court on December 2, 1942. Recalled are Columbia University experiments which did much to establish the feasibility of the chain in natural uranium and which stimulated the creation of the Manhattan District. The Columbia group moved to the University of Chicago, where, in early summer of 1942, construction and analysis of a number of subcritical reactors (piles) gave assurance with a high probability that only a reasonable amount of uranium and moderator would be required

  8. Giant resonances: reaction theory approach

    International Nuclear Information System (INIS)

    Toledo Piza, A.F.R. de; Foglia, G.A.

    1989-09-01

    The study of giant resonances through the use of reaction theory approach is presented and discussed. Measurements of cross-sections to the many available decay channels following excitation of giant multipole resonances (GMR) led one to view these phenomena as complicated dynamical syndromes so that theoretical requirements for their study must be extended beyond the traditional bounds of nuclear structure models. The spectra of decay products following GMR excitation in heavy nuclei are well described by statistical model (Hauser-Feshback, HF) predictions indicated that spreading of the collective modes plays a major role in shaping exclusive cross-sections. (A.C.A.S.) [pt

  9. Kinetics of heterogeneous catalytic reactions

    CERN Document Server

    Boudart, Michel

    2014-01-01

    This book is a critical account of the principles of the kinetics of heterogeneous catalytic reactions in the light of recent developments in surface science and catalysis science. Originally published in 1984. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase acc

  10. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2002-01-01

    Full text: Department of Nuclear Reactions has had a very productive year. We have carried out our work in close collaborations with physicists from many laboratories, home and foreign. The following reports cover three major domains of our activities: nuclear, material and atomic physics. * Nuclear physics: In collaboration with scientists from Ukraine experimental studies of nuclear reaction induced by heavy ions from the Warsaw Cyclotron have been performed. The aim of the experiments is to study nuclear reactions leading to the exotic light nuclei in exit channels and energy dependence of the nucleus - nucleus interactions. Proton induced charge-exchange reactions were investigated theoretically by means of multistep-direct model. Good agreement with the experimental data was achieved. A novel approach to the problem of the nuclear liquid → gas phase transition was proposed, based on synergetics - a domain of science dealing with self-organization in macroscopic systems. Decay properties of the Roper resonance were studied. Final analysis of the analysing powers for the polarized deuterons scattered on protons was accomplished. Experimental programme of the near-threshold meson production in proton - proton scattering has been started in collaboration with Forschungszentrum. Juelich. * Atomic physics: Spectra of the X-rays emitted by energetic sulphur ions scattered off carbon atoms were analysed in order to study the role of the multiple charge states of the inner shells in the dynamics of the collision process. Ionization probabilities in collision of oxygen ions with gold atoms were measured. The observed disagreement of the experimental data with the theoretical predictions suggest a strong effect generated by the sub-shell couplings. * Materials research: Ion channelling method was applied to investigate transformation of the defects in Al x Ga 1-x As crystalline layers. Activities of our colleagues in didactics have grown considerably. Lectures

  11. Anaphylactic reaction to intravenous cefazolin.

    Science.gov (United States)

    Faulk, D; Rodosevich, K; Katz, R L; Calmes, S H

    1993-12-01

    Allergic responses to cefazolin occur in approximately 3% to 5% of patients. The responsibility of the health care professional includes developing an awareness that histamine release in varying degrees can occur with the administration of a variety of drugs utilized throughout the perioperative period. The authors discuss the cardiopulmonary manifestations resulting from the release of histamine during an allergic reaction. Differentiation of diagnosis of the causative agent, the effective treatment of the anaphylactic response during anesthesia, and preventive measures to reduce anesthesia morbidity are examined.

  12. Dibaryon resonances in photon induced reactions

    International Nuclear Information System (INIS)

    Schwille, W.J.

    1981-11-01

    The author gives a review about the production of dibaryon resonances in photon reactions on deuterium targets. Especially he considers the reactions γ + d → p + n, γ + d → p + X, and γ + d → p + N + π. (HSI)

  13. Catalyst Initiation in the Oscillatory Carbonylation Reaction

    Directory of Open Access Journals (Sweden)

    Katarina Novakovic

    2011-01-01

    Full Text Available Palladium(II iodide is used as a catalyst in the phenylacetylene oxidative carbonylation reaction that has demonstrated oscillatory behaviour in both pH and heat of reaction. In an attempt to extract the reaction network responsible for the oscillatory nature of this reaction, the system was divided into smaller parts and they were studied. This paper focuses on understanding the reaction network responsible for the initial reactions of palladium(II iodide within this oscillatory reaction. The species researched include methanol, palladium(II iodide, potassium iodide, and carbon monoxide. Several chemical reactions were considered and applied in a modelling study. The study revealed the significant role played by traces of water contained in the standard HPLC grade methanol used.

  14. Organic chemistry - Fast reactions 'on water'

    NARCIS (Netherlands)

    Klijn, JE; Engberts, JBFN

    2005-01-01

    Efficient reactions in aqueous organic chemistry do not require soluble reactants, as had been thought. A newly developed ‘on-water’ protocol is characterized by short reaction times, and the products are easy to isolate.

  15. Amazing variational approach to chemical reactions

    OpenAIRE

    Fernández, Francisco M.

    2009-01-01

    In this letter we analyse an amazing variational approach to chemical reactions. Our results clearly show that the variational expressions are unsuitable for the analysis of empirical data obtained from chemical reactions.

  16. The mechanism of the modified Ullmann reaction

    NARCIS (Netherlands)

    Sperotto, Elena; Klink, Gerard P.M. van; Koten, Gerard van; Vries, Johannes G. de

    2010-01-01

    The copper-mediated aromatic nucleophilic substitution reactions developed by Fritz Ullmann and Irma Goldberg required stoichiometric amounts of copper and very high reaction temperatures. Recently, it was found that addition of relatively cheap ligands (diamines, aminoalcohols, diketones, diols)

  17. Scattering and transfer reactions with heavy ions

    International Nuclear Information System (INIS)

    Hussein, M.S.

    From the elastic scattering analysis the input parameters are found for the inelastic scattering analysis and the transfer reactions of the heavy ion reactions. The main theme reported is the likeness and conection among these processes. (L.C.) [pt

  18. Competing reaction channels in IR-laser-induced unimolecular reactions

    International Nuclear Information System (INIS)

    Berman, M.R.

    1981-01-01

    The competing reaction channels in the unimolecular decomposition of two molecules, formaldehyde and tetralin were studied. A TEA CO 2 laser was used as the excitation source in all experiments. The dissociation of D 2 CO was studied by infrared multiphoton dissociation (MPD) and the small-molecule nature of formaldehyde with regard to MPD was explored. The effect of collisions in MPD were probed by the pressure dependence of the MPD yield and ir fluorescence from multiphoton excited D 2 CO. MPD yield shows a near cubic dependence in pure D 2 CO which is reduced to a 1.7 power dependence when 15 torr of NO is added. The peak amplitude of 5 μm ir fluorescence from D 2 CO is proportional to the square of the D 2 CO pressure in pure D 2 CO or in the presence of 50 torr of Ar. Results are explained in terms of bottlenecks to excitation at the v = 1 level which are overcome by a combination of vibrational energy transfer and rotational relaxation. The radical/molecule branching ratio in D 2 CO MPD was 0.10 +- 0.02 at a fluence of 125 J/cm 2 at 946.0 cm -1 . The barrier height to molecular dissociation was calculated to be 3.6 +- 2.0 kcal/mole below the radical threshold or 85.0 +- 3.0 kcal/mole above the ground state of D 2 CO. In H 2 CO, this corresponds to 2.5 +- 2.0 kcal/mole below the radical threshold or 83.8 +- 3.0 kcal/mole above the ground state. Comparison with uv data indicate that RRKM theory is an acceptable description of formaldehyde dissociation in the 5 to 10 torr pressure range. The unimolecular decomposition of tetralin was studied by MPD and SiF 4 - sensitized pyrolysis. Both techniques induce decomposition without the interference of catalytic surfaces. Ethylene loss is identified as the lowest energy reaction channel. Dehydrogenation is found to result from step-wise H atom loss. Isomerization via disproportionation is also identified as a primary reaction channel

  19. Catalysis of Nuclear Reactions by Electrons

    Science.gov (United States)

    Lipoglavšek, Matej

    2018-01-01

    Electron screening enhances nuclear reaction cross sections at low energies. We studied the nuclear reaction 1H(19F,αγ)16O in inverse kinematics in different solid hydrogen targets. Measured resonance strengths differed by up to a factor of 10 in different targets. We also studied the 2H(p,γ)3He fusion reaction and observed electrons emitted as reaction products instead of γ rays. In this case electron screening greatly enhances internal conversion probability.

  20. Nuclear reaction rates and the primordial nucleosynthesis

    OpenAIRE

    Mishra, Abhishek; Basu, D. N.

    2011-01-01

    The theoretical predictions of the primordial abundances of elements in the big-bang nucleosynthesis (BBN) are dominated by uncertainties in the input nuclear reaction rates. We investigate the effect of modifying these reaction rates on light element abundance yields in BBN by replacing the thirty-five reaction rates out of the existing eighty-eight. We have studied these yields as functions of evolution time or temperature. We find that using these new reaction rates results in only a littl...

  1. Catalysis of Nuclear Reactions by Electrons

    Directory of Open Access Journals (Sweden)

    Lipoglavšek Matej

    2017-01-01

    Full Text Available Electron screening enhances nuclear reaction cross sections at low energies. We studied the nuclear reaction 1H(19F,αγ16O in inverse kinematics in different solid hydrogen targets. Measured resonance strengths differed by up to a factor of 10 in different targets. We also studied the 2H(p,γ3He fusion reaction and observed electrons emitted as reaction products instead of γ rays. In this case electron screening greatly enhances internal conversion probability.

  2. The Reaction of Oxy Hemoglobin with Nitrite

    DEFF Research Database (Denmark)

    Hathazi, Denisa; Scurtu, Florina; Bischin, Cristina

    2018-01-01

    -peroxynitrate. Density functional theory (DFT) calculations support this latter assignment. The reaction allows for differentiating between the reactivities of various chemically modified hemoglobins, including candidates for blood substitutes. Polymerization of hemoglobin slows the nitrite-induced oxidation, in sharp...... contrast to oxidative-stress type reactions which are generally accelerated, not inhibited. Sheep hemoglobin is found to be distinctly more resistant to reaction with nitrite compared to bovine Hb, at large nitrite concentrations (stopped-flow experiments directly observing the oxy + nitrite reaction...

  3. Multi-step direct reactions

    International Nuclear Information System (INIS)

    Koning, A.J.

    1992-07-01

    In recent years a variety of statistical theories has been developed concerning multistep direct (MSD) nuclear reactions. In addition, dominant in applications is a whole class of semiclassical models that may be subsumed under the heading of 'generalized exciton models'; these are basically MSD-type extensions on top of compound-like concepts. In this report the relation between their underlying statistical MSD-postulates are highlighted. A command framework is sketched that enables to generate the various MSD theories through assigning statistical properties to different parts of the nuclear Hamiltonian. Then it is shown that distinct forms of nuclear randomness are embodied in the mentioned theories. All these theories appear to be very similar at a qualitative level. In order to explain the high energy-tails and forward-peaked angular distribution typical for particles emitted in MSD reactions, it is imagined that the incident continuum particle stepwise looses its energy and direction in a sequence of collisions, thereby creating new particle-hole pairs in the target system. At each step emission may take place. The statistical aspect comes in because many continuum states are involved in the process. These are supposed to display chaotic behavior, the associated randomness assumption giving rise to important simplifications in the expression for MSD emission cross sections. This picture suggests that mentioned MSD models can be interpreted as a variant of essentially one and the same theory. 113 refs.; 25 figs.; 9 tabs

  4. Enantioselective solvent-free Robinson annulation reactions

    Indian Academy of Sciences (India)

    Unknown

    The use of proline or any other amino acid in asymmetric annulation reactions in a solid–liquid phase reaction in the absence of solvents to effect an asymmetric synthesis is an important step forward towards cleaner synthesis 2. ... Reports on solvent-free reactions have become increasingly frequent and the field has.

  5. Infrared laser-induced chemical reactions

    International Nuclear Information System (INIS)

    Katayama, Mikio

    1978-01-01

    The experimental means which clearly distinguishes between infrared ray-induced reactions and thermal reactions has been furnished for the first time when an intense monochromatic light source has been obtained by the development of infrared laser. Consequently, infrared laser-induced chemical reactions have started to develop as one field of chemical reaction researches. Researches of laser-induced chemical reactions have become new means for the researches of chemical reactions since they were highlighted as a new promising technique for isotope separation. Specifically, since the success has been reported in 235 U separation using laser in 1974, comparison of this method with conventional separation techniques from the economic point of view has been conducted, and it was estimated by some people that the laser isotope separation is cheaper. This report briefly describes on the excitation of oscillation and reaction rate, and introduces the chemical reactions induced by CW laser and TEA CO 2 laser. Dependence of reaction yield on laser power, measurement of the absorbed quantity of infrared ray and excitation mechanism are explained. Next, isomerizing reactions are reported, and finally, isotope separation is explained. It was found that infrared laser-induced chemical reactions have the selectivity for isotopes. Since it is evident that there are many examples different from thermal and photo-chemical reactions, future collection of the data is expected. (Wakatsuki, Y.)

  6. Reaction-Map of Organic Chemistry

    Science.gov (United States)

    Murov, Steven

    2007-01-01

    The Reaction-Map of Organic Chemistry lists all the most commonly studied reactions in organic chemistry on one page. The discussed Reaction-Map will act as another learning aide for the students, making the study of organic chemistry much easier.

  7. Reaction Order Ambiguity in Integrated Rate Plots

    Science.gov (United States)

    Lee, Joe

    2008-01-01

    Integrated rate plots are frequently used in reaction kinetics to determine orders of reactions. It is often emphasised, when using this methodology in practice, that it is necessary to monitor the reaction to a substantial fraction of completion for these plots to yield unambiguous orders. The present article gives a theoretical and statistical…

  8. Allergic reactions seen in orthodontic treatment

    Directory of Open Access Journals (Sweden)

    Hande Görücü Coşkuner

    2016-01-01

    Full Text Available Allergy can be defined as inappropriate and harmful response to harmless and ordinary materials. Allergic reactions, like in other fields of dentistry, can also be seen in the field of orthodontics. The reactions that occur against orthodontic materials can be seen as irritant or hypersensitivity reactions. The main reason of the irritant reactions is friction between soft tissues and orthodontic appliances. However, the reason of the hypersensitivity reactions is usually the antigenicity of the materials. Hypersensitivity reactions are usually seen as allergic contact dermatitis on face and neck; the occurrence of mucosal-gingival reactions and dermal and systemic reactions are rare. Latex, metal and acrylic resins are the most common allergens in orthodontics. Apart from these materials, allergic reactions can occur against bonding materials, extraoral appliances, disinfectants and antimicrobial agents. The reactions that occur against extraoral appliances usually result from metallic and elastic parts of the appliances or the appliance parts that are in contact with skin. Orthodontists should be aware of the allergic reactions to protect their patients’ health. The aim of this review was to evaluate the allergic reactions seen in orthodontic patients and discuss the cautions that orthodontists can take.

  9. Modelling Students' Visualisation of Chemical Reaction

    Science.gov (United States)

    Cheng, Maurice M. W.; Gilbert, John K.

    2017-01-01

    This paper proposes a model-based notion of "submicro representations of chemical reactions". Based on three structural models of matter (the simple particle model, the atomic model and the free electron model of metals), we suggest there are two major models of reaction in school chemistry curricula: (a) reactions that are simple…

  10. Method of controlling fusion reaction rates

    Science.gov (United States)

    Kulsrud, Russell M.; Furth, Harold P.; Valeo, Ernest J.; Goldhaber, Maurice

    1988-01-01

    A method of controlling the reaction rates of the fuel atoms in a fusion reactor comprises the step of polarizing the nuclei of the fuel atoms in a particular direction relative to the plasma confining magnetic field. Fusion reaction rates can be increased or decreased, and the direction of emission of the reaction products can be controlled, depending on the choice of polarization direction.

  11. Parental Reactions to Cleft Palate Children.

    Science.gov (United States)

    Vanpoelvoorde, Leah

    This literature review examines parental reactions following the birth of a cleft lip/palate child, focusing primarily on the mother's reactions. The research studies cited have explored such influences on maternal reactions as her feelings of lack of control over external forces and her feelings of guilt that the deformity was her fault. Delays…

  12. The Rate Laws for Reversible Reactions.

    Science.gov (United States)

    King, Edward L.

    1986-01-01

    Provides background information for teachers on the rate laws for reversible reactions. Indicates that although prediction of the form of the rate law for a reverse reaction given the rate law for the forward reaction is not certain, the number of possibilities is limited because of relationships described. (JN)

  13. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2001-01-01

    Full text: The last year of the twentieth-century was productive for our Department. Although the name of the Department suggests that we are all involved in investigations of nuclear reactions, in fact our activities are spread over three major domains: nuclear, atomic and material physics. Some of the projects we were involved in the last year have been realized using national facilities and accelerators, like the Van de Graaff accelerator of our Department at 69 Hoza Street, Warsaw Cyclotron U-200P of Warsaw University, and compact C30 cyclotron of our Institute at Swierk. Other projects were done abroad, using facilities of the Gesellschaft fuer Schwerionenforschung in Darmstadt, Institute de Physique Nucleaire at Orsay, and Universitaet Erlangen-Nuernberg in Erlangen. We carried out our work in close collaborations with physicists from many laboratories, Polish and foreign. - Low energy nuclear reactions. In collaboration with scientists from Ukraine experiments, using heavy ion beam provided by the Warsaw Cyclotron, were started. The aim of the experiments is to study nuclear reactions leading to the exotic light nuclei in exit channels and energy dependence of the nucleus - nucleus interaction. Efforts were made to develop a multistep direct model of nuclear reactions. In the model contributions due to the low energy collective excitations were taken into account. Good agreement with the experimental data was achieved. - Multifragmentation of relativistic heavy ions. ALADIN Collaboration studied multifragmentation reactions induced by relativistic heavy ions. The main activities of our scientists concentrated on an upgrade of the detecting system in order to replace photo multipliers with large area avalanche photodiodes in the central section of the TOF-wall. Some tests of the photodiodes manufactured by Advanced Photonix Inc. were performed using standard β - and γ-sources. - Structure of a nucleon. Decay properties of the Roper resonance were studied. A

  14. Reactions of butadiyne. 1: The reaction with hydrogen atoms

    Science.gov (United States)

    Schwanebeck, W.; Warnatz, J.

    1984-01-01

    The reaction of hydrogen (H) atoms with butadiene (C4H2) was studied at room temperature in a pressure range between w mbar and 10 mbar. The primary step was an addition of H to C4H2 which is in its high pressure range at p 1 mbar. Under these conditions the following addition of a second H atom lies in the transition region between low and high pressure range. Vibrationally excited C4H4 can be deactivated to form buten-(1)-yne-(3)(C4H4) or decomposes into two C2H2 molecules. The rate constant at room temperature for primary step is given. The second order rate constant for the consumption of buten-(1)-yne-(3) is an H atom excess at room temperature is given.

  15. Fundamental study on reaction of lead-bismuth eutectic and sodium. Identification of reaction products and examination of reaction behavior

    International Nuclear Information System (INIS)

    Saito, Jun-ichi; Hirakawa, Yasushi

    2003-09-01

    A simplified secondary sodium cooling system utilizing lead-bismuth eutectic as an intermediate coolant has been selected as one of candidate systems for the 'Feasibility Studies on Commercialized Fast Reactor System'. In this study, fundamental reaction experiments have been performed to understand a reaction behavior between sodium and lead-bismuth. In order to identify the reaction products and to elucidate a reaction process, sampling and X-ray diffraction analysis of the reaction products are carried out. Following results are obtained. (1) The principal reaction products which formed in sodium and lead-bismuth ternary system are BiNa 3 and Pb 4 Na 15 intermetallic compounds. These two reaction products are identified irrespective of either primary sample content or sampling temperature. (2) Pb 3 Na intermetallic compound is identified in the reaction products for the first time. (3) The principal reaction product which formed in sodium and bismuth binary system is BiNa 3 intermetallic compound. (4) The reaction products which formed in sodium and lead binary system consist of various intermetallic compounds of sodium and lead system. Single phase of an intermetallic compound can not be obtained in this system. Based on these X-ray diffraction analyses, reaction process models of formation and dissolution are proposed. (author)

  16. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2003-01-01

    Full text: In 2002, the Department has been involved in two new experimental programmes. Our colleagues led by Prof. Pawel Zupranski joined a large international collaboration HERMES and took part in experiments at DESY devoted to the study of the spin structure of the nucleon. Another group directed by Associate Prof. Bogdan Zwieglinski has worked on a conceptual design of a new generation detector PANDA (Proton-Antiproton Detection) which will be used in future experiments at GSI. Moreover, the experimental programmes covering three major domains of our scientific activities: nuclear physics, materials research and atomic physics were continued. - Nuclear physics: Experimental studies of nuclear reactions induced by heavy ions provided by the Warsaw U-200P Cyclotron were performed in collaboration with scientists from the Institute for Nuclear Studies in Kiev, Ukraine. The aim of the experiments was to investigate isotopic effects in the scattering of 11 B from carbon nuclides. Also, excited states of 6 Li predicted theoretically but never seen in experiments were investigated by means of one-neutron transfer reactions. Proton induced reactions were investigated theoretically by means of the multistep-direct model. Good agreement with the experimental data was achieved. The mechanism of fragments production in collisions of 197 Au with a gold target in the wide range of energies was studied by ALADIN and INDRA Collaborations. The production of η mesons from proton - proton collisions was investigated experimentally at the Juelich Cooler Synchrotron COSY. - Atomic physics: The ionisation of Au, Bi, Th and U atoms by Si ions was investigated in collaboration with the Swietokrzyska Academy, Kielce, and the University of Erlangen-Nuernberg. - Materials research: The sensitivity of the Solid State Nuclear Track PM-355 detectors was tested against intensive gamma and electron radiation. Moreover, using a monoenergetic sulphur ion beam from the Warsaw Cyclotron, the

  17. Kinetic studies of elementary chemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Durant, J.L. Jr. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    This program concerning kinetic studies of elementary chemical reactions is presently focussed on understanding reactions of NH{sub x} species. To reach this goal, the author is pursuing experimental studies of reaction rate coefficients and product branching fractions as well as using electronic structure calculations to calculate transition state properties and reaction rate calculations to relate these properties to predicted kinetic behavior. The synergy existing between the experimental and theoretical studies allow one to gain a deeper insight into more complex elementary reactions.

  18. Incidents of chemical reactions in cell equipment

    Energy Technology Data Exchange (ETDEWEB)

    Baldwin, N.M.; Barlow, C.R. [Uranium Enrichment Organization, Oak Ridge, TN (United States)

    1991-12-31

    Strongly exothermic reactions can occur between equipment structural components and process gases under certain accident conditions in the diffusion enrichment cascades. This paper describes the conditions required for initiation of these reactions, and describes the range of such reactions experienced over nearly 50 years of equipment operation in the US uranium enrichment program. Factors are cited which can promote or limit the destructive extent of these reactions, and process operations are described which are designed to control the reactions to minimize equipment damage, downtime, and the possibility of material releases.

  19. Computed potential energy surfaces for chemical reactions

    Science.gov (United States)

    Walch, Stephen P.

    1994-01-01

    Quantum mechanical methods have been used to compute potential energy surfaces for chemical reactions. The reactions studied were among those believed to be important to the NASP and HSR programs and included the recombination of two H atoms with several different third bodies; the reactions in the thermal Zeldovich mechanism; the reactions of H atom with O2, N2, and NO; reactions involved in the thermal De-NO(x) process; and the reaction of CH(squared Pi) with N2 (leading to 'prompt NO'). These potential energy surfaces have been used to compute reaction rate constants and rates of unimolecular decomposition. An additional application was the calculation of transport properties of gases using a semiclassical approximation (and in the case of interactions involving hydrogen inclusion of quantum mechanical effects).

  20. Department of Nuclear Reactions - Overview

    International Nuclear Information System (INIS)

    Budzanowski, A.

    1999-01-01

    Full text: The year 1998 can be considered as very successful both in harvesting important results from the existing collaborations as well as establishing new ones. In the frame of the COSY-11 collaboration cross section for η' production in p-p collision close to the threshold has been measured. In the region of excess energy between 1.5 and 4.1 MeV the η' cross sections are much lower than those of the π 0 and η production. There seems to be no indication that N * resonance doorway-like state governs the reaction mechanisms. The determined coupling constant g η'pp appears to be consistent with the prediction of the simple quark model. Results were published in Phys. Rev. Letters. Using the GEM detector, investigations of the isospin symmetry breaking were performed. Two reactions channels 3 Heπ 0 and 3 Hπ + from the reaction at proton momenta 700, 767, and 825 MeV/c were measured. Data analysis is in progress. The model of the meson cloud in the nucleon which is a speciality of our department has been successfully applied to explain the leading proton and neutron cross sections from the e + or e - proton collisions at the HERA ring. General formulas to calculate polarization of the particles with spin transmitted through the barrier in the presence of strong magnetic fields were obtained. New collaboration between our laboratory and the Institute for Nuclear Research in Kiev has been established. One PhD thesis was completed in the frame of this collaboration. We joined the new collaboration with Lund University concerning studies of hot nuclear matter properties using heavy ions from CELSIUS ring. First test of the phoswich detector for the forward wall was performed in Uppsala. Isoscalar giant dipole resonance strength distribution 3 ℎω has been evaluated in 208 Pb in the space of 1p1h and 2p2h excitation. The centroid energy of this state can directly be related to the nuclear incompressibility module. Our result indicates rather large values of

  1. The OH + HBr reaction revisited

    Science.gov (United States)

    Ravishankara, A. R.; Wine, P. H.; Wells, J. R.

    1985-01-01

    Variable-temperature measurements of the rate coefficient /k(1)/ for the reaction OH + HBr yield Br + H2O are presented. The measurements are verified by two techniques: one involved a 266-nm pulsed-laser photolysis of O3/H2O/HBr/He mixtures in conjunction with time-resolved resonance fluorescence detection of OH, the second comprised pulsed laser-induced fluorescence detection of OH following 248-nm pulsed-laser photolysis of H2O2/HBr/Ar mixtures. It is reported that k(1) = (11.9 + or -1.4 x 10 to the -12th (cu cm)/(molecule)(s) independent of temperature. The measurements are compared with other available results.

  2. Stochastic chemical reactions in microdomains

    Science.gov (United States)

    Holcman, D.; Schuss, Z.

    2005-03-01

    Traditional chemical kinetics may be inappropriate to describe chemical reactions in microdomains involving only a small number of substrate and reactant molecules. Starting with the stochastic dynamics of the molecules, we derive a master-diffusion equation for the joint probability density of a mobile reactant and the number of bound substrate in a confined domain. We use the equation to calculate the fluctuations in the number of bound substrate molecules as a function of initial reactant distribution. A second model is presented based on a Markov description of the binding and unbinding and on the mean first passage time of a molecule to a small portion of the boundary. These models can be used for the description of noise due to gating of ionic channels by random binding and unbinding of ligands in biological sensor cells, such as olfactory cilia, photoreceptors, hair cells in the cochlea.

  3. Selected aspects of fusion reactions

    International Nuclear Information System (INIS)

    Lacroix, D.

    2003-01-01

    In this lecture, we present selected aspects of nuclear fusion. The importance of the initial geometry of the reaction and its relation to fusion barrier are first discussed. The effect of deformation leading to the notion of barrier distribution is then illustrated. After a brief overview of the advantages of macroscopic theories, the dynamics of nuclear system under large amplitude motion is reviewed. The di-nuclear concept is presented to understand the competition between fusion and quasi-fission. This concept is then generalized to account for the dissipative dynamics in multidimensional collective space. The last part of this lecture is devoted to new aspects encountered with radioactive beams specific properties of very extended neutron rich system, influence of pygmy or soft dipole resonances and charge exchange far from stability are discussed. (author)

  4. Cold molecules, collisions and reactions

    Science.gov (United States)

    Hecker Denschlag, Johannes

    2016-05-01

    I will report on recent experiments of my group where we have been studying the formation of ultracold diatomic molecules and their subsequent inelastic/reactive collisions. For example, in one of these experiments we investigate collisions of triplet Rb2 molecules in the rovibrational ground state. We observe fast molecular loss and compare the measured loss rates to predictions based on universality. In another set of experiments we investigate the formation of (BaRb)+ molecules after three-body recombination of a single Ba+ ion with two Rb atoms in an ultracold gas of Rb atoms. Our investigations indicate that the formed (BaRb)+ molecules are weakly bound and that several secondary processes take place ranging from photodissociation of the (BaRb)+ molecule to reactive collisions with Rb atoms. I will explain how we can experimentally distinguish these processes and what the typical reaction rates are. Support from the German Research foundation DFG and the European Community is acknowledged.

  5. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2004-01-01

    Full text: In spite of reduced personnel the number of papers published and in press exceeded fifty, almost ten more than a year ago. Another good sign is the growing number of PhD students. The following short reports cover the three major domains of our scientific activities: nuclear, material and atomic physics. Nuclear physics: The structure of light nuclei was investigated, and studies of nuclear reactions induced by heavy ions were performed including experiments at the Heavy Ion Laboratory of Warsaw University. The experiments were carried out in collaboration with scientists from the Institute of Nuclear Research from Kiev, Ukraine. Proton induced reactions on zirconium were investigated theoretically by means of a multistep-direct model extended for the unbound particle - hole states. Good agreement with the experimental data was achieved. Isospin effects in multifragmentation of relativistic heavy ions were studied by the ALADIN Collaboration. Elements of a new generation detector PANDA were tested experimentally using a proton beam provided by the C-30 compact cyclotron at Swierk. Evidence of a narrow baryon state was found in a quasi - real photoproduction on the deuterium target by the HERMES Collaboration. Atomic physics: Ionisation of selected heavy elements by sulphur ions was investigated in collaboration with the Swietokrzyska Academy, Kielce. Materials research: Hydrogen release from ultrahigh molecular weight polythene was investigated by means of an α - particle beam from the Van de Graaff accelerator of our Department. Last but not least, many of our colleagues have been involved in education. Lectures on nuclear physics, accelerators, detectors used in nuclear research as well as nuclear methods applied in solid state studies for students from many high schools of Warsaw and for students of Warsaw University were given by Dr. Andrzej Korman and Dr. Lech Nowicki. Also, our Department made a significant contribution to the 7 th Science

  6. Subdiffusion-reaction processes with A →B reactions versus subdiffusion-reaction processes with A +B→B reactions

    Science.gov (United States)

    Kosztołowicz, Tadeusz; Lewandowska, Katarzyna D.

    2014-09-01

    We consider the subdiffusion-reaction process with reactions of a type A +B→B (in which particles A are assumed to be mobile, whereas B are assumed to be static) in comparison to the subdiffusion-reaction process with A →B reactions which was studied by Sokolov, Schmidt, and Sagués [Phys. Rev. E 73, 031102 (2006), 10.1103/PhysRevE.73.031102]. In both processes a rule that reactions can only occur between particles which continue to exist is taken into account. Although in both processes a probability of the vanishing of particle A due to a reaction is independent of both time and space variables (assuming that in the system with the A +B→B reactions, particles B are distributed homogeneously), we show that subdiffusion-reaction equations describing these processes as well as their Green's functions are qualitatively different. The reason for this difference is as follows. In the case of the former reaction, particles A and B have to meet with some probability before the reaction occurs in contradiction with the case of the latter reaction. For the subdiffusion process with the A +B→B reactions we consider three models which differ in some details concerning a description of the reactions. We base the method considered in this paper on a random walk model in a system with both discrete time and discrete space variables. Then the system with discrete variables is transformed into a system with both continuous time and continuous space variables. Such a method seems to be convenient in analyzing subdiffusion-reaction processes with partially absorbing or partially reflecting walls. The reason is that within this method we can determine Green's functions without a necessity of solving a fractional differential subdiffusion-reaction equation with boundary conditions at the walls. As an example, we use the model to find the Green's functions for a subdiffusive reaction system (with the reactions mentioned above), which is bounded by a partially absorbing wall

  7. RxnFinder: biochemical reaction search engines using molecular structures, molecular fragments and reaction similarity.

    Science.gov (United States)

    Hu, Qian-Nan; Deng, Zhe; Hu, Huanan; Cao, Dong-Sheng; Liang, Yi-Zeng

    2011-09-01

    Biochemical reactions play a key role to help sustain life and allow cells to grow. RxnFinder was developed to search biochemical reactions from KEGG reaction database using three search criteria: molecular structures, molecular fragments and reaction similarity. RxnFinder is helpful to get reference reactions for biosynthesis and xenobiotics metabolism. RxnFinder is freely available via: http://sdd.whu.edu.cn/rxnfinder. qnhu@whu.edu.cn.

  8. Reaction time variability in ADHD: a review.

    Science.gov (United States)

    Tamm, Leanne; Narad, Megan E; Antonini, Tanya N; O'Brien, Kathleen M; Hawk, Larry W; Epstein, Jeffery N

    2012-07-01

    For the past decade, intra-individual variability in reaction times on computerized tasks has become a central focus of cognitive research on Attention-Deficit/Hyperactivity Disorder (ADHD). Numerous studies document increased reaction time variability among children and adults with ADHD, relative to typically developing controls. However, direct comparisons with other disorders with heightened reaction time variability are virtually nonexistent, despite their potential to inform our understanding of the phenomenon. A growing literature examines the sensitivity of reaction time variability to theoretically and clinically relevant manipulations. There is strong evidence that stimulus treatment reduces reaction time variability during a range of cognitive tasks, but the literature is mixed regarding the impact of motivational incentives and variation in stimulus event rate. Most studies of reaction time variability implicitly assume that heightened reaction time variability reflects occasional lapses in attention, and the dominant neurophysiological interpretation suggests this variability is linked to intrusions of task-negative brain network activity during task performance. Work examining the behavioral and neurophysiological correlates of reaction time variability provides some support for these hypotheses, but considerably more work is needed in this area. Finally, because conclusions from each of domains reviewed are limited by the wide range of measures used to measure reaction time variability, this review highlights the need for increased attention to the cognitive and motivational context in which variability is assessed and recommends that future work always supplement macro-level variability indices with metrics that isolate particular components of reaction time variability.

  9. Explorations into Chemical Reactions and Biochemical Pathways.

    Science.gov (United States)

    Gasteiger, Johann

    2016-12-01

    A brief overview of the work in the research group of the present author on extracting knowledge from chemical reaction data is presented. Methods have been developed to calculate physicochemical effects at the reaction site. It is shown that these physicochemical effects can quite favourably be used to derive equations for the calculation of data on gas phase reactions and on reactions in solution such as aqueous acidity of alcohols or carboxylic acids or the hydrolysis of amides. Furthermore, it is shown that these physicochemical effects are quite effective for assigning reactions into reaction classes that correspond to chemical knowledge. Biochemical reactions constitute a particularly interesting and challenging task for increasing our understanding of living species. The BioPath.Database is a rich source of information on biochemical reactions and has been used for a variety of applications of chemical, biological, or medicinal interests. Thus, it was shown that biochemical reactions can be assigned by the physicochemical effects into classes that correspond to the classification of enzymes by the EC numbers. Furthermore, 3D models of reaction intermediates can be used for searching for novel enzyme inhibitors. It was shown in a combined application of chemoinformatics and bioinformatics that essential pathways of diseases can be uncovered. Furthermore, a study showed that bacterial flavor-forming pathways can be discovered. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    1999-01-01

    Full text: The Department of Nuclear Reactions had a very productive year. The following reports cover three major domains of our activities: nuclear, material and atomic physics. One of the current questions in modern nuclear physics is question of the phase transitions in nuclear matter. Our physicists, the members of the ALADIN Collaboration at Gesellschaft fuer Schwerionenforschung, participated in new experiments exploring properties of highly excited nuclear matter and the phenomenon of the liquid - gas phase transition. The experiments yielded a number of important results. Details can be found in the three short reports presented in this volume. Structure of a nucleon is another important subject of nuclear science research. In the last year energy region of Δ resonance has been investigated by means of charge exchange reaction. The experiment was performed at Laboratory National Saturne in Saclay by SPESIV-π collaboration consisting of physicist from Institute of Nuclear Physics Orsay, Niels Bohr Institute Copenhagen and from our Department. The main achievement of the experiment was evidence for a Δ - hole attraction in the spin longitudinal channel. Reactions induced by radioactive ion beams such as 6 He recently attract a lot of interest. There exist some evidences that the 6 He nucleus has a two-neutron halo structure similar to that well established for 11 Li. An analysis of 6 He + 4 He scattering data reported in this volume revealed some similarities between the loosely bound 6 Li nucleus and the neutron rich 6 He. Research in material physics has focused on two basic topics: a crystallographic model of uranium dioxide, a material currently used as a nuclear fuel and transformations of defects in GaAs crystals at low temperature. The investigations have been carried out in a wide collaboration with scientists from the University of Jena, Research Center Karlsruhe and Centre de Spectrometrie Nucleaire Orsay. Some experiments have been performed at

  11. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    1998-01-01

    (full text) During the last year our activities were spread over the three major domains: nuclear, atomic and material physics. The nuclear physics experimental programme covered a broad range of nuclear reactions induced by light and heavy ions. New experiments were performed at the compact C-30 cyclotron at Swierk, at University of Jyvaeskylae, GSI Darmstadt, LN Saturne. Prospects for future experiments on nucleon structure at Forschungszentrum Juelich were open. The collaboration with INR Kiev was tightened and work was done in order to prepare experiments at the C-200 heavy ion cyclotron in Warsaw. An effort to install the ion guide isotope separator on line (IGISOL) at the C-200 cyclotron has also to be mentioned A half a year stay of Dr. Nicholas Keeley in the Department, who received The Royal Society/Polish Academy of Science grant, resulted in many interesting results on breakup of light nuclei. Details can be found in the short abstracts presented in this report. As far as atomic physics is concerned, the activity of a group lead by Prof. Marian Jaskola yielded various new results. The experiments were performed at the University of Erlangen, in close collaboration with the Pedagogical University in Kielce and the University of Basel. Fast neutrons generated in the 3 H(d,n) 4 He reaction induced by the 2 MeV deuteron beam from the Van der Graaff accelerator at the Department were used to calibrate solid state-nuclear-track detectors. This was a very good year for material physics research: Jan Kaczanowski and Slawomir Kwiatkawski received Ph.D. degrees based on dissertation research performed in the material physics research programme, while Pawel Kolodziej completed his MSc. thesis in collaboration with the Institute of Electronic Materials Technology in Warsaw, Research Center Karlsruhe, University of Jena and CSNSM Orsay many results were obtained. Lech Nowicki and Prof. Andrzej Turos were awarded by the Director of the IPJ prizes for their scientific

  12. ReactionPredictor: prediction of complex chemical reactions at the mechanistic level using machine learning.

    Science.gov (United States)

    Kayala, Matthew A; Baldi, Pierre

    2012-10-22

    Proposing reasonable mechanisms and predicting the course of chemical reactions is important to the practice of organic chemistry. Approaches to reaction prediction have historically used obfuscating representations and manually encoded patterns or rules. Here we present ReactionPredictor, a machine learning approach to reaction prediction that models elementary, mechanistic reactions as interactions between approximate molecular orbitals (MOs). A training data set of productive reactions known to occur at reasonable rates and yields and verified by inclusion in the literature or textbooks is derived from an existing rule-based system and expanded upon with manual curation from graduate level textbooks. Using this training data set of complex polar, hypervalent, radical, and pericyclic reactions, a two-stage machine learning prediction framework is trained and validated. In the first stage, filtering models trained at the level of individual MOs are used to reduce the space of possible reactions to consider. In the second stage, ranking models over the filtered space of possible reactions are used to order the reactions such that the productive reactions are the top ranked. The resulting model, ReactionPredictor, perfectly ranks polar reactions 78.1% of the time and recovers all productive reactions 95.7% of the time when allowing for small numbers of errors. Pericyclic and radical reactions are perfectly ranked 85.8% and 77.0% of the time, respectively, rising to >93% recovery for both reaction types with a small number of allowed errors. Decisions about which of the polar, pericyclic, or radical reaction type ranking models to use can be made with >99% accuracy. Finally, for multistep reaction pathways, we implement the first mechanistic pathway predictor using constrained tree-search to discover a set of reasonable mechanistic steps from given reactants to given products. Webserver implementations of both the single step and pathway versions of Reaction

  13. A clock reaction based on molybdenum blue.

    Science.gov (United States)

    Neuenschwander, Ulrich; Negron, Arnaldo; Jensen, Klavs F

    2013-05-30

    Clock reactions are rare kinetic phenomena, so far limited mostly to systems with ionic oxoacids and oxoanions in water. We report a new clock reaction in cyclohexanol that forms molybdenum blue from a noncharged, yellow molybdenum complex as precursor, in the presence of hydrogen peroxide. Interestingly, the concomitant color change is reversible, enabling multiple clock cycles to be executed consecutively. The kinetics of the clock reaction were experimentally characterized, and by adding insights from quantum chemical calculations, a plausible reaction mechanism was postulated. Key elementary reaction steps comprise sigmatropic rearrangements with five-membered or bicyclo[3.1.0] transition states. Importantly, numerical kinetic modeling demonstrated the mechanism's ability to reproduce the experimental findings. It also revealed that clock behavior is intimately connected to the sudden exhaustion of hydrogen peroxide. Due to the stoichiometric coproduction of ketone, the reaction bears potential for application in alcohol oxidation catalysis.

  14. Delayed reactions to reusable protective gloves.

    Science.gov (United States)

    Pontén, Ann; Dubnika, Inese

    2009-04-01

    The materials in plastic protective gloves are thought to cause less contact allergy than rubber gloves. Our aim was to estimate the frequency of delayed reactions to different types of reusable protective gloves among dermatitis patients. 2 x 2 cm pieces of polyvinyl chloride (PVC) gloves, nitrile gloves, and natural rubber latex (NRL) gloves were tested as is in consecutive dermatitis patients tested with the baseline series. Among 658 patients, 6 patients reacted to PVC gloves and 6 patients to the NRL gloves. None reacted to both these types of gloves. Five of six patients with reactions to rubber gloves reacted to thiuram mix in the baseline series. Delayed reactions to reusable PVC gloves may be as common as to reusable NRL gloves. In contrast to most reactions to the NRL glove, the reactions to the PVC glove had no obvious association with reactions to any allergen(s) in the baseline series.

  15. Ladle Metallurgy Kinetics: Inclusion-Inclusion Reactions

    Science.gov (United States)

    Pistorius, P. Chris

    An example is presented to illustrate the joint effect of local reaction equilibria and mass transfer limitations, for reactions during ladle refining of steel. The example relies on some of the kinetic principles that David Robertson has employed to quantify many metallurgical processes. In calcium treatment of alumina inclusions in aluminum-killed steels, solid CaS forms as an intermediate reaction product. During subsequent reaction, CaS disappears and calcium aluminate forms; at the same time, aluminum and sulfur dissolve in the steel. Kinetic analysis shows that the rate of this reaction is not limited by mass transfer of dissolved aluminum and sulfur away from the reacting inclusions. The reaction rate is likely limited by transport of dissolved calcium. This example also illustrates the use of FactSage macros for kinetic modeling.

  16. Orienting reaction in patients with night terrors.

    Science.gov (United States)

    Rogozea, R; Florea-Ciocoiu, V

    1985-08-01

    A polygraphic study of the somatic (electromyogram), autonomic (finger plethysmogram, galvanic skin reaction, respiration, pulse), and electroencephalographic (acoustic-evoked potential and EEG-blocking reaction) components of the orienting reaction elicited by an auditory stimulus was performed in 36 patients with night terrors and in 72 matched subjects in two control groups. The study showed a significantly more intense orienting reaction in patients with night terrors than in normal subjects (Control Group I). Moreover, the orienting reaction intensity in subjects with night terrors was significantly lower than in patients with symptomatic epilepsy (Control Group II). The orienting reactions of patients with night terrors depended on the patient's age, the history of nocturnal episodes, and their clinical form, as well as on etiology.

  17. Proton transfer reaction - mass spectrometry

    International Nuclear Information System (INIS)

    Cappellin, L.

    2012-01-01

    Proton transfer reaction mass spectrometry (PTR-MS) provides on-line monitoring of volatile organic compounds (VOCs) with a low detection threshold and a fast response time. Commercially available set-ups are usually based on quadrupole analysers but recently new instruments based on time-of-flight (PTR-ToF-MS) analysers have been proposed and commercialized. PTR-MS has been successfully applied to a variety of fields including environmental science, food science and technology, plant physiology and medical science. Many new challenges arise from the newly available PTR-ToF-MS instruments, ranging from mass calibration and absolute VOC concentration determination to data mining and sample classification. This thesis addresses some of these problems in a coherent framework. Moreover, relevant applications in food science and technology are presented. It includes twelve papers published in peer reviewed journals. Some of them address methodological issues regarding PTR-ToF-MS; the others contain applicative studies of PTR-ToF-MS to food science and technology. Among them, there are the first two published applications of PTR-ToF-MS in this field. (author)

  18. Alchemical derivatives of reaction energetics

    Science.gov (United States)

    Sheppard, Daniel; Henkelman, Graeme; von Lilienfeld, O. Anatole

    2010-08-01

    Based on molecular grand canonical ensemble density functional theory, we present a theoretical description of how reaction barriers and enthalpies change as atoms in the system are subjected to alchemical transformations, from one element into another. The change in the energy barrier for the umbrella inversion of ammonia is calculated along an alchemical path in which the molecule is transformed into water, and the change in the enthalpy of protonation for methane is calculated as the molecule is transformed into a neon atom via ammonia, water, and hydrogen fluoride. Alchemical derivatives are calculated analytically from the electrostatic potential in the unperturbed system, and compared to numerical derivatives calculated with finite difference interpolation of the pseudopotentials for the atoms being transformed. Good agreement is found between the analytical and numerical derivatives. Alchemical derivatives are also shown to be predictive for integer changes in atomic numbers for oxygen binding to a 79 atom palladium nanoparticle, illustrating their potential use in gradient-based optimization algorithms for the rational design of catalysts.

  19. Quantum indistinguishability in chemical reactions.

    Science.gov (United States)

    Fisher, Matthew P A; Radzihovsky, Leo

    2018-04-30

    Quantum indistinguishability plays a crucial role in many low-energy physical phenomena, from quantum fluids to molecular spectroscopy. It is, however, typically ignored in most high-temperature processes, particularly for ionic coordinates, implicitly assumed to be distinguishable, incoherent, and thus well approximated classically. We explore enzymatic chemical reactions involving small symmetric molecules and argue that in many situations a full quantum treatment of collective nuclear degrees of freedom is essential. Supported by several physical arguments, we conjecture a "quantum dynamical selection" (QDS) rule for small symmetric molecules that precludes chemical processes that involve direct transitions from orbitally nonsymmetric molecular states. As we propose and discuss, the implications of the QDS rule include ( i ) a differential chemical reactivity of para- and orthohydrogen, ( ii ) a mechanism for inducing intermolecular quantum entanglement of nuclear spins, ( iii ) a mass-independent isotope fractionation mechanism, ( iv ) an explanation of the enhanced chemical activity of "reactive oxygen species", ( v ) illuminating the importance of ortho-water molecules in modulating the quantum dynamics of liquid water, and ( vi ) providing the critical quantum-to-biochemical linkage in the nuclear spin model of the (putative) quantum brain, among others.

  20. Interfacial reactions in lithium batteries

    Science.gov (United States)

    Chen, Zonghai; Amine, Rachid; Ma, Zi-Feng; Amine, Khalil

    2017-08-01

    The lithium-ion battery was first commercially introduced by Sony Corporation in 1991 using LiCoO2 as the cathode material and mesocarbon microbeads (MCMBs) as the anode material. After continuous research and development for 25 years, lithium-ion batteries have been the dominant energy storage device for modern portable electronics, as well as for emerging applications for electric vehicles and smart grids. It is clear that the success of lithium-ion technologies is rooted to the existence of a solid electrolyte interphase (SEI) that kinetically suppresses parasitic reactions between the lithiated graphitic anodes and the carbonate-based non-aqueous electrolytes. Recently, major attention has been paid to the importance of a similar passivation/protection layer on the surface of cathode materials, aiming for a rational design of high-energy-density lithium-ion batteries with extended cycle/calendar life. In this article, the physical model of the SEI, as well as recent research efforts to understand the nature and role of the SEI are summarized, and future perspectives on this important research field will also be presented.

  1. Estimating the Backup Reaction Wheel Orientation Using Reaction Wheel Spin Rates Flight Telemetry from a Spacecraft

    Science.gov (United States)

    Rizvi, Farheen

    2013-01-01

    A report describes a model that estimates the orientation of the backup reaction wheel using the reaction wheel spin rates telemetry from a spacecraft. Attitude control via the reaction wheel assembly (RWA) onboard a spacecraft uses three reaction wheels (one wheel per axis) and a backup to accommodate any wheel degradation throughout the course of the mission. The spacecraft dynamics prediction depends upon the correct knowledge of the reaction wheel orientations. Thus, it is vital to determine the actual orientation of the reaction wheels such that the correct spacecraft dynamics can be predicted. The conservation of angular momentum is used to estimate the orientation of the backup reaction wheel from the prime and backup reaction wheel spin rates data. The method is applied in estimating the orientation of the backup wheel onboard the Cassini spacecraft. The flight telemetry from the March 2011 prime and backup RWA swap activity on Cassini is used to obtain the best estimate for the backup reaction wheel orientation.

  2. ADVERSE DRUG REACTION (ADR) MONITORING AND PHARMACOVIGILANCE

    OpenAIRE

    D. KAVITHA

    2013-01-01

    The need for systematic follow up of medicines for adverse drug reactions once they are introduced into general use has been widely recognised today. Even in developing countries like India, national pharmacovigilance programme has been started for monitoring adverse drug reactions. In its first year this program mainly aimed to foster the culture of ADR notification among health care professionals. As a part of health care team every pharmacist must have knowledge about adverse drug reaction...

  3. Physical organic studies of organometallic reactions

    Energy Technology Data Exchange (ETDEWEB)

    Bergman, Robert G. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

    1981-01-01

    The mechanisms of reactions of organotransition metal complexes have only begun to be understood in detail during the last ten years. The complementary interaction of techniques and concepts developed earlier in studies of organic reaction mechanisms, with those commonly used in inorganic chetnistry, has played a crucial role in helping to elucidate organor.1etall.ic reaction mechanisms. A few systems in which this interaction has proved especially fruitful are discussed in this article.

  4. Molecular dynamics simulation of a chemical reaction

    International Nuclear Information System (INIS)

    Gorecki, J.; Gryko, J.

    1988-06-01

    Molecular dynamics is used to study the chemical reaction A+A→B+B. It is shown that the reaction rate constant follows the Arrhenius law both for Lennard-Jones and hard sphere interaction potentials between substrate particles. A. For the denser systems the reaction rate is proportional to the value of the radial distribution function at the contact point of two hard spheres. 10 refs, 4 figs

  5. Severe allergic reactions to guinea pig

    OpenAIRE

    Zacharisen, Michael C; Levy, Michael B; Shaw, Jeffrey L; Kurup, Viswanath P

    2005-01-01

    Abstract Background Allergic sensitization and reactions to guinea pig (Cavia porcellus) have been well documented in laboratory animal handlers, primarily manifesting as rhinitis, conjunctivitis, and asthma. Severe allergic reactions, however, are rare. Methods We report two patients with severe allergic reactions following non-occupational exposure to guinea pigs. The first patient, an 11-year-old female, developed ocular, nasal, skin and laryngeal edema symptoms immediately after handling ...

  6. Nucleon transfer reactions with radioactive beams

    Science.gov (United States)

    Wimmer, K.

    2018-03-01

    Transfer reactions are a valuable tool to study the single-particle structure of nuclei. At radioactive beam facilities transfer reactions have to be performed in inverse kinematics. This creates a number of experimental challenges, but it also has some advantages over normal kinematics measurements. An overview of the experimental and theoretical methods for transfer reactions, especially with radioactive beams, is presented. Recent experimental results and highlights on shell evolution in exotic nuclei are discussed.

  7. Mukaiyama Aldol Reactions in Aqueous Media

    OpenAIRE

    Kitanosono, Taku; Kobayashi, Shū

    2013-01-01

    Mukaiyama aldol reactions in aqueous media have been surveyed. While the original Mukaiyama aldol reactions entailed stoichiometric use of Lewis acids in organic solvents under strictly anhydrous conditions, Mukaiyama aldol reactions in aqueous media are not only suitable for green sustainable chemistry but are found to produce singular phenomena. These findings led to the discovery of a series of water-compatible Lewis acids such as lanthanide triflates in 1991. Our understanding on these be...

  8. Asian collaboration on nuclear reaction data compilation

    International Nuclear Information System (INIS)

    Aikawa, Masayuki; Furutachi, Naoya; Kato, Kiyoshi; Makinaga, Ayano; Devi, Vidya; Ichinkhorloo, Dagvadorj; Odsuren, Myagmarjav; Tsubakihara, Kohsuke; Katayama, Toshiyuki; Otuka, Naohiko

    2013-01-01

    Nuclear reaction data are essential for research and development in nuclear engineering, radiation therapy, nuclear physics and astrophysics. Experimental data must be compiled in a database and be accessible to nuclear data users. One of the nuclear reaction databases is the EXFOR database maintained by the International Network of Nuclear Reaction Data Centres (NRDC) under the auspices of the International Atomic Energy Agency. Recently, collaboration among the Asian NRDC members is being further developed under the support of the Asia-Africa Science Platform Program of the Japan Society for the Promotion of Science. We report the activity for three years to develop the Asian collaboration on nuclear reaction data compilation. (author)

  9. Experimental Studies of quasi-fission reactions

    International Nuclear Information System (INIS)

    Back, B.B.

    1989-01-01

    A large number of recent experimental studies have shown that a substantial fraction of the total reaction cross section in heavy-ion reactions is found in fission-like processes, which do not result from the fission decay of a completely fused system. Following the suggestion of Swiatecki such processes, which represents a complete relaxation of the relative kinetic energy and a substantial amount of net mass transfer between the two fragments, are denoted quasi-fission reactions. They are distinct from compound fission reactions by bypassing the stage of a completely fused system. This typically means that they are associated with short reaction times, which results in several measurable characteristics such as broken forward-backward symmetries, large anisotropies of the angular distributions and increased widths of the fragment mass distributions. The distinction between quasi-fission and deep inelastic reactions is less stringent and has the character of a gradual evolution from one reaction type to the other, as found also as quasi-elastic reaction evolves into deeply inelastic processes as a function of the total kinetic energy loss. In the present paper some of the experimental data characterizing quasi-fission reactions are reviewed and discussed. (author)

  10. Sodium-concrete reaction model development

    International Nuclear Information System (INIS)

    Nguyen, D.H.; Muhlestein, L.D.; Postma, A.K.

    1982-07-01

    Major observations have been formulated after reviewing test results for over 100 sodium-concrete reaction tests. The observations form the basis for developing a mechanistic model to predict the transient behavior of sodium-concrete reactions. The major observations are listed. Mechanisms associated with sodium and water transport to the reaction zone are identified, and represented by appropriate mathematical expressions. The model attempts to explain large-scale, long-term (100 h) test results were sodium-concrete reactions terminated even in the presence of unreacted sodium and concrete

  11. Catalytic enantioselective Reformatsky reaction with ketones

    NARCIS (Netherlands)

    Fernandez-Ibanez, M. Angeles; Macia, Beatriz; Minnaard, Adriaan J.; Feringa, Ben L.

    2008-01-01

    Chiral tertiary alcohols were obtained with good yields and enantioselectivities via a catalytic Reformatsky reaction with ketones, including the challenging diaryl ketones, using chiral BINOL derivatives.

  12. The unified theory of nuclear reactions

    International Nuclear Information System (INIS)

    Tobocman, W.

    A unified nuclear reaction theory is a formalism for the scattering reactions of many-body nuclear systems which is capable of describing both direct interaction and compound nucleus formation processes. The Feshbach projection operator formalism is the original unified nuclear reaction theory. An alternative unified nuclear reaction theory called the X-matrix formalism is described. The X-matrix formalism is a generalization of the Brown-de Dominicis formalism. It does not require projection operators and is readly applied to rearrangement collisions

  13. Screened Thermonuclear Reaction Rates on Magnetar Surfaces

    International Nuclear Information System (INIS)

    Hong-Lin, Liu; Zhi-Quan, Luo; Jing-Jing, Liu; Xiang-Jun, Lai

    2008-01-01

    Improving Salpeter's method, we discuss the effect of superstrong magnetic fields (such as those of magnetars) on thermonuclear reaction rates. These most interesting reactions, including the hydrogen burning by the CNO cycle and the helium burning by the triple alpha reaction, are investigated as examples on the magnetar surfaces. The obtained result shows that the superstrong magnetic fields can increase the thermonuclear reaction rates by many orders of magnitude. The enhancement may have significant influence for further study research of the magnetars, especially for the x-ray luminosity observation and the evolution of magnetars. (geophysics, astronomy, and astrophysics)

  14. Verification of cold nuclear fusion reaction, (1)

    International Nuclear Information System (INIS)

    Yoshida, Zenko; Aratono, Yasuyuki; Hirabayashi, Takakuni

    1991-01-01

    Can cold nuclear fusion reaction occur as is expected? If it occurs, what extent is its reaction probability? At present after 2 years elapsed since its beginning, the clear solution of these questions is not yet obtained. In many reaction systems employing different means, the experiments to confirm the cold nuclear fusion reaction have been attempted. In order to confirm that the nuclear fusion reaction of deuterium mutually has occurred, the neutrons, He-3, protons, tritium or generated heat, which were formed by the reaction and released from the system, are measured. Since it is considered that the frequency of the occurrence at normal temperature of the reaction is very low, it is necessary to select the most suitable method upon evaluating the limit of detection peculiar to the measuring methods. The methods of measuring neutrons, protons, gamma ray and generated heat, and the reaction systems by electrolytic process and dry process are explained. The detection of plural kinds of the reaction products and the confirmation of synchronism of signals are important. (K.I.)

  15. A study on sodium-concrete reaction

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Jae Heum; Min, Byong Hun [Suwon University, Suwon (Korea, Republic of)

    1997-07-01

    A small sodium-concrete reaction facility was designed, manufactured and installed. this facility has been operated under inert gas(N{sub 2}) with different experimental variables such as sodium injection temperature, injection amount of sodium, aging period of concrete, sodium reservoir temperature. As a result, it was found that sodium injection temperature and injected amount of sodium has little effect on sodium-concrete reaction. However, sodium reservoir temperature and aging period of concrete has relatively high impact on sodium-concrete reaction. Sodium-concrete reaction model has also been developed and compared with experimental results. (Author) 51 refs., 16 tabs., 64 figs.

  16. Bimolecular reactions of carbenes: Proton transfer mechanism

    Science.gov (United States)

    Abu-Saleh, Abd Al-Aziz A.; Almatarneh, Mansour H.; Poirier, Raymond A.

    2018-04-01

    Here we report the bimolecular reaction of trifluoromethylhydroxycarbene conformers and the water-mediated mechanism of the 1,2-proton shift for the unimolecular trans-conformer by using quantum chemical calculations. The CCSD(T)/cc-pVTZ//MP2/cc-pVDZ potential-energy profile of the bimolecular reaction of cis- and trans-trifluoromethylhydroxycarbene, shows the lowest gas-phase barrier height of 13 kJ mol-1 compared to the recently reported value of 128 kJ mol-1 for the unimolecular reaction. We expect bimolecular reactions of carbene's stereoisomers will open a valuable field for new and useful synthetic strategies.

  17. Catalytic Wittig and aza-Wittig reactions

    Directory of Open Access Journals (Sweden)

    Zhiqi Lao

    2016-11-01

    Full Text Available This review surveys the literature regarding the development of catalytic versions of the Wittig and aza-Wittig reactions. The first section summarizes how arsenic and tellurium-based catalytic Wittig-type reaction systems were developed first due to the relatively easy reduction of the oxides involved. This is followed by a presentation of the current state of the art regarding phosphine-catalyzed Wittig reactions. The second section covers the field of related catalytic aza-Wittig reactions that are catalyzed by both phosphine oxides and phosphines.

  18. Catalytic Wittig and aza-Wittig reactions.

    Science.gov (United States)

    Lao, Zhiqi; Toy, Patrick H

    2016-01-01

    This review surveys the literature regarding the development of catalytic versions of the Wittig and aza-Wittig reactions. The first section summarizes how arsenic and tellurium-based catalytic Wittig-type reaction systems were developed first due to the relatively easy reduction of the oxides involved. This is followed by a presentation of the current state of the art regarding phosphine-catalyzed Wittig reactions. The second section covers the field of related catalytic aza-Wittig reactions that are catalyzed by both phosphine oxides and phosphines.

  19. Chemical reactions in low-g

    Science.gov (United States)

    Grodzka, P. G.; Facemire, B. R.

    1978-01-01

    The Apollo-Soyuz flight experiment, 'Chemical Foams' demonstrated that foams and air/liquid dispersions are much more stable in low-gravity than on the ground. It thus should be possible to conduct unique chemical reactions in space foams. The low-g results and subsequent ground work on the formaldehyde clock reaction indicate that the reaction is strongly influenced by (1) dissociated and undissociated solution species being adsorbed at solid/liquid and gas/liquid surfaces and (2) chemical reaction rates apparently being affected by long-range forces determined by the liquid mass and the extent and nature of all surface interfaces.

  20. Road- and civil engineering. 10. rev. and enl. ed.; Strassen- und Tiefbau

    Energy Technology Data Exchange (ETDEWEB)

    Richter, D.; Heindel, M.

    2008-07-01

    In nearly 30 years, this book has become a standard textbook for students of road engineering and civil engineering. It provides a clear and competent introduction to comprehensive knowledge in this field. The 10th edition has been completely revised and edited, with new chapters on semi-rigid roofs, modernisation and repair of pipelines, and shafts and modern concrete road construction. The book contains many pictures, mostly in colour, a bibliography and important internet links. (orig.)

  1. Contemporary health physics. Problems and solutions. 2. upd. and enl. ed.

    International Nuclear Information System (INIS)

    Bevelacqua, Joseph John

    2009-01-01

    This is the first text specifically designed to train potential health physicists to think and respond like professionals, offering a balanced presentation of all the theoretical and practical aspects essential for a full working knowledge of radiation exposure assessments. As the only book to cover the entire radiation protection field, it includes detailed coverage of the medical, university, fuel cycle, power reactor, environmental and accelerator, and nonionizing radiation areas, while exploring key topics in radiation basics, external and internal dosimetry, the biological effects of ionizing radiation, and much more besides. Backed by more than 500 worked examples spanning the full spectrum of real-world challenges, it quickly instills in readers the professional acumen and practical skills needed to perform accurate radiation assessments in virtually any routine or emergency situation. (orig.)

  2. EEG. Renewables Act. Comment. 4. new rev. and enl. ed.; EEG. Erneuerbare-Energien-Gesetz. Kommentar

    Energy Technology Data Exchange (ETDEWEB)

    Frenz, Walter [RWTH Aachen Univ. (Germany). Lehr- und Forschungsgebiet Berg-, Umwelt- und Europarecht; Mueggenborg, Hans-Juergen [Technische Hochschule Aachen (Germany); Kassel Univ. (Germany); Cosack, Tilman [Hochschule Trier, Umwelt-Campus Birkenfeld (Germany). IREK - Inst. fuer das Recht der Erneuerbaren Energien, Energieeffizienzrecht und Klimaschutzrecht; Ekardt, Felix (ed.) [Forschungsstelle Nachhaltigkeit und Klimapolitik, Leipzig (Germany)

    2015-07-01

    Unlike any other Act, the Renewable Energy Sources Act (EEG) changes continuously. Recently it has been fundamentally transformed with the amendment 2014. Comprehensive, readable and practice-oriented. The proven Berliner comment EEG is your reliable companion through the new regulatory regime. All provisions of the EEG 2014 thorough and easy to understand commented by experts of the matter. 2. The EEG Amending Act of 29.6.2015 has already been considered. A detailed introduction and contributions to the relevant European law and the antitrust aspects of the renewable energy sources to guarantee you a broad understanding of the rules. Valuable background information you provide, the digressions of the most important renewable energy technologies, will explain the pictures thanks to numerous the scientific and technical foundations. Moreover you the construction law aspects in the construction of photovoltaic and wind turbines are explained clearly. [German] Wie kaum ein anderes Gesetz veraendert sich das Erneuerbare-Energien-Gesetz (EEG) laufend. Zuletzt wurde es mit der Novelle 2014 grundlegend umgestaltet. Umfassend, verstaendlich und praxisgerecht Der bewaehrte Berliner Kommentar EEG ist Ihr verlaesslicher Begleiter durch das neue Regelungsregime. Alle Vorschriften des EEG 2014 werden gruendlich und leicht verstaendlich von Kennern der Materie kommentiert. Das 2. EEG-Aenderungsgesetz vom 29.06.2015 ist bereits beruecksichtigt. Eine ausfuehrliche Einleitung sowie Beitraege zum einschlaegigen europaeischen Recht und zu den kartellrechtlichen Aspekten der erneuerbaren Energien verhelfen Ihnen zu einem breiten Verstaendnis der Vorschriften. Wertvolles Hintergrundwissen liefern Ihnen auch die Exkurse zu den wichtigsten Erneuerbare-Energien-Technologien, die Ihnen dank zahlreicher Abbildungen die naturwissenschaftlich-technischen Grundlagen erlaeutern. Zudem werden Ihnen die baurechtlichen Aspekte bei der Errichtung von Photovoltaik- und Windenergieanlagen uebersichtlich erklaert.

  3. Purification and characterization of a new cold active lipase, EnL A ...

    African Journals Online (AJOL)

    SONU

    2015-06-03

    Jun 3, 2015 ... SDS PAGE analysis revealed that the protein is monomeric with a MW of ˜54 kDa and zymogram .... Triton X-100 and 10 mg of gum arabic. The mixture was incubated at 30°C for 30 min ... The molecular weight of the purified lipase was determined by SDS-. PAGE using Laemmli method (Laemmli, 1970).

  4. Imaging of the head and neck. 2. rev. and enl. ed

    Energy Technology Data Exchange (ETDEWEB)

    Mafee, M.F.; Valvassori, G.E. [University of Illinois, Chicago, IL (United States); Becker, M. [Geneva University Hospital (Switzerland)

    2004-07-01

    Remarkable advances in medical diagnostic imaging have been made during the past three decades. The development of new imaging techniques and continuous improvements in the display of digital images have opened new horizons in the study of head and neck anatomy and pathology. The American Society of Head and Neck Radiology (ASHNR) and its European and Asiatic counterparts evolved because of the emerging awareness of the roles that head and neck radiologists play in the diagnosis and management of head and neck, base of the skull, neuro-ophthalmologic and neuro-otologic diseases. This edition continues the tradition of excellence set by the first edition of Valvassori's Head and Neck Imaging (which was also the first textbook in head and neck radiology), and provides a comprehensive review of the most pertinent and up-to-date knowledge in the field of head and neck imaging. The content of this edition has been organized into 12 chapters according to anatomic regions. It now includes new material on the temporomandibular joint, the lacrimal drainage system, dental scanning, fibro-osseous and cartilaginous lesions of the head and neck, MRI sialography, MR interventional technique, and thyroid and parathyroid glands. All chapters have been expanded to address new developments in the field and to stress the importance of imaging anatomy, pathologic correlation, and pertinent clinical data. For each anatomic region, the embryology and anatomy are introduced, followed by congenital and developmental disorders, inflammatory processes, benign and malignant neoplastic diseases, trauma, and postoperative changes. The detailed reference lists in each chapter include key references and are as recent as possible. Care has been taken to include exquisitely reproduced illustrations that provide the maximum of pertinent information. It is our hope that this textbook will be useful to students and physicians in the fields of radiology, otolaryngology, neurootology, rhinology, head and neck surgery, ophthalmology, neuroophthalmology, oromaxillofacial-temporomandibular surgery, neurology, neurosurgery, and oncology. (orig.)

  5. Manual for the energy trade. 3. new rev. and enl. ed.; Handbuch Energiehandel

    Energy Technology Data Exchange (ETDEWEB)

    Schwintowski, Hans-Peter (ed.) [Humboldt-Universitaet, Berlin (Germany)

    2014-07-01

    This manual sheds a light on the energy trade from both a legal and an empirical economic perspective. Its focus is on those business fields within the energy trade that are of foremost practical relevance, namely the OTC trade and the exchange trade. It also provides concise coverage of risk management systems in the energy trade along with a competent account of their implications with regard to supervisory regulations. In this, its third edition the manual addresses the latest developments in both the national and the international energy trade, including those seen in the gas storage market and its market access regulations; consideration is here also given to market transparency, market distortion and liquidity. The commentary on standard contracts (EFET) has been updated. The manual also addresses the adaptations made in the minimum requirements for risk management.

  6. Transesophageal echocardiography. 3. rev. and enl. ed.; Transoesophageale Echokardiografie. Lehrbuch und Altlas zur Untersuchungstechnik und Befundinterpretation

    Energy Technology Data Exchange (ETDEWEB)

    Lambertz, Heinz [ECHOECUCT-Akademie, Wiesbaden (Germany); Lethen, Harald (eds.) [Internistische Intensivmedizin, Wiesbaden (Germany). Innere Medizin/Kardiologie

    2013-02-01

    The book on transesophageal echocardiography covers the following issues: Development of transesophageal echocardiography, technical advances; indications and contraindication for transesophageal echocardiography; systematic of the medical examination process; cardiac valves and valve prostheses; mitral and aortic valvuloplasty, TAVI and interventional treatment of mitral regurgitation; infectious endocarditis; one-way and effluence disturbances of the left and right ventricle; diseases of the thoracic aorta; undefined right ventricle enlargement; lung embolism, acute infarct complications; TEE during anesthesia and perioperative intensive medicine, cardiac sources of embolism; cardiac tumors, mediastinal lymph nodes; pericardiac diseases; congenital heart diseases in childhood and adulthood; catheter interventions and heart valve reconstruction; surgically corrected congenital cardiac defects; intracavitary versus transesophageal echocardiography; three-dimensional TEE; coronary diagnostics; ischemia and vitality diagnostics.

  7. The MR trainer. Upper extremities. 2. rev. and enl. ed.; Der MR-Trainer. Obere Extremitaet

    Energy Technology Data Exchange (ETDEWEB)

    Breitenseher, Martin [Landesklinikum Waldviertel Horn (Austria). Inst. fuer Radiologie und Interventionelle Radiologie

    2016-05-01

    The MR (magnetic resonance) trainer covers the indications in NMR images of hands, elbows and shoulder, including fractures and instabilities at the wrist, tendon and ligament lesions, carpal tunnel syndrome, ulnar tunnel syndrome, scaphoid bone fracture, (posttraumatic) osteonecrosis, synovial lesions, luxations, osteocondrosis, soft tissue rumors and bone tumors. The book includes training tasks for each issue.

  8. Imaging of the head and neck. 2. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Mafee, M.F.; Valvassori, G.E.; Becker, M.

    2004-01-01

    Remarkable advances in medical diagnostic imaging have been made during the past three decades. The development of new imaging techniques and continuous improvements in the display of digital images have opened new horizons in the study of head and neck anatomy and pathology. The American Society of Head and Neck Radiology (ASHNR) and its European and Asiatic counterparts evolved because of the emerging awareness of the roles that head and neck radiologists play in the diagnosis and management of head and neck, base of the skull, neuro-ophthalmologic and neuro-otologic diseases. This edition continues the tradition of excellence set by the first edition of Valvassori's Head and Neck Imaging (which was also the first textbook in head and neck radiology), and provides a comprehensive review of the most pertinent and up-to-date knowledge in the field of head and neck imaging. The content of this edition has been organized into 12 chapters according to anatomic regions. It now includes new material on the temporomandibular joint, the lacrimal drainage system, dental scanning, fibro-osseous and cartilaginous lesions of the head and neck, MRI sialography, MR interventional technique, and thyroid and parathyroid glands. All chapters have been expanded to address new developments in the field and to stress the importance of imaging anatomy, pathologic correlation, and pertinent clinical data. For each anatomic region, the embryology and anatomy are introduced, followed by congenital and developmental disorders, inflammatory processes, benign and malignant neoplastic diseases, trauma, and postoperative changes. The detailed reference lists in each chapter include key references and are as recent as possible. Care has been taken to include exquisitely reproduced illustrations that provide the maximum of pertinent information. It is our hope that this textbook will be useful to students and physicians in the fields of radiology, otolaryngology, neurootology, rhinology, head and neck surgery, ophthalmology, neuroophthalmology, oromaxillofacial-temporomandibular surgery, neurology, neurosurgery, and oncology. (orig.)

  9. Dictionary of power engineering and automation. Pt. 1. 3. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Bezner, H.

    1993-01-01

    The dictionary has been prepared by the Translation Department of Siemens AG and essentially covers the following subjects: Basic electrotechnical terms and standards, Electrical machines (including transformers), Switchgear, Electrical systems and networks, Electrical installation practice (including lighting), Power cables, Power electronics, Protective devices and relays, Electrical measuring and analysis technology, Telecontrol, Automotive electronics, Semiconductor devices, integrated circuits, Automation technology (control engineering, programmable and numerical controls, process control), Bus systems, communication networks, data transmission and communication, Test engineering, Quality assurance and reliability. For the third edition, the dictionary has been thoroughly revised and about 2000 terms have been added, primarily referring to the subject of process control, so that the edition in hand contains approximately 65 000 entires. Sources referred to for this dictionary include: VDE specifications, DIN, VDI, IEC, BS, ANSI, CEE and ISO standards, technical literature and descriptions and operating instructions from German, British and American companies. The results of the European harmonization of electrotechnical regulations (DIN/ VDE/IEC/CEE) have been taken into account. (orig./HP) [de

  10. Purification and characterization of a new cold active lipase, EnL A ...

    African Journals Online (AJOL)

    Search of lipase engineering data base (LED) revealed that this protein belongs to a newly introduced super family of Candida antarctica lipase A like and to the homologous family of Aspergillus lipase like. Key words: Cold active lipase, Emericella nidulans, hydrophobic interaction chromatography, Candida antarctica ...

  11. The natural radioactivity of plants, animals and humans. 3. enl. ed.

    International Nuclear Information System (INIS)

    Schewtschenko, I.N.; Danilenko, A.I.

    2007-01-01

    The natural radioactivity of plants, animals and humans are of important scientific relevance for radiobiology and medicine. The possible effects of micro doses during life span are still controversially discussed. Part I of the book (the natural radioactivity of plants, animals and humans for the normal case and in case of pathological changes) covers the following topics: the natural radioisotopes in living organisms (plants, animals, humans) and their environment; methodologies of qualitative and quantitative determination of beta-activity in biological objects; the radioactivity of atmospheric precipitations; the beta-activity of plants; the beta-activity of animals; beta-activity of human organs and tissues. Part II (dynamics of radionuclides in the biological chains in the period 1960 to 2007): the modern conceptions on the biological role of natural radioactive elements, biological indications during early stages of low-dose ionizing irradiation; the radioactivity of the human blood; radiation and carcerogenesis

  12. Foundations of a new possible all-comprehending theory. 4. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Agnotos, A.

    2005-01-01

    Knowledge of sciences concerning a theory for all represent the starting point of the present book. Questions concerning our universe as well as further thinkable universes - among others such, which result from computer simulations - are treated. The hypothesis of the author is that all, what is thinkable and logically consistent, exists. He formulates and studies numerous open questions. At time we live in an extremeously regular universe, i. e. the physical laws are equally valid on the whole earth, additionally we assume that this is also valid in the observed farly removed regions of the universe. If the hypothesis that all exists, what is thinkable and logically consistent, is applied in a too simplified way among others by means of theoretical computer simulations, it would seemingly result that irregular universes wold be, simplifedly expressed, much more abundant than the extremeously regular ones. Also it would seem that extremeously many universes, in which we would also exist, would by for instance in intermediate future completely irregular. If the irregular ones, simpifiedly expressed, would be extremely more abundant, why we just live in an extremely regular univers, which remains also in future such regular? This question calls the author as probability paradoxon of the existence. New kwoledge of the complexity theor suggest the answer to the questions. therefore the hypothesis, that all exists, what is thinkable and logically consistent, remains valid

  13. Doppler ultrasound in obstetrics and gynecology. 2. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Maulik, D.

    2005-01-01

    The second edition of Doppler Ultrasound in Obstetrics and Gynecology has been expanded and comprehensively updated to present the current standards of practice in Doppler ultrasound and the most recent developments in the technology. Doppler Ultrasound in Obstetrics and Gynecology encompasses the full spectrum of clinical applications of Doppler ultrasound for the practicing obstetrician-gynecologist, including the latest advances in 3D and color Doppler and the newest techniques in 4D fetal echocardiography. Written by preeminent experts in the field, the book covers the basic and physical principles of Doppler ultrasound; the use of Doppler for fetal examination, including fetal cerebral circulation; Doppler echocardiography of the fetal heart; and the use of Doppler for postdated pregnancy and in cases of multiple gestation. Chapters on the use of Doppler for gynecologic investigation include ultrasound in ectopic pregnancy, for infertility, for benign disorders and for gynecologic malignancies. (orig.)

  14. Vieweg manual of motor car engineering. 3. tot. new rev. and enl. ed.; Vieweg Handbuch Kraftfahrzeugtechnik

    Energy Technology Data Exchange (ETDEWEB)

    Braess, H.H.; Seiffert, U. (eds.)

    2003-07-01

    This is the 3rd, revised and re-edited edition. Current trends are considered, i.e. DI and variable valve operation, particulate filters, double clutch gears, ESP-Plus, SUN-Fuel, and variable adaptive lighting. There are new chapters on standardisation (e.g. telematics and interface problems), accident research, internals, software, service-friendly design, maintenance and diagnosis, as well as sports and racing cars. Contents: Requirements on motor cars; Innovative technologies; Aerodynamics; Air conditioning; Acoustics; Design; Package; Fuel cell; Electric vehicles; Gas turbine; Spark ignition engine; Diesel engine; Superchargers; Couplings and gears; Four-wheel drives; Brakes and control systems; Two-stroke engines; Car bodies; Materials; Surface protection; Passenger compartment; Safety; Brakes; Tyres; Chassis; Fuels; Electric and electronic systems; Software; Driver assistant systems; Lighting; Sensors; Onboard network; EMP; Materials; Simultaneous engineering; Simulations; Experimental technologies; Motor cars and transportation in the future; Legislation and standardisation; Accident research; Diagnosis and maintenance; Racing cars and sports cars. [German] Fahrzeugingenieure in Praxis und Ausbildung benoetigen den raschen und sicheren Zugriff auf Grundlagen und Details der Fahrzeugtechnik sowie wesentliche zugehoerige industrielle Prozesse. Solche Informationen, die in ganz unterschiedlichen Quellen abgelegt sind, systematisch und bewertend zusammenzufuehren, hat sich dieses Handbuch zum Ziel gesetzt. Die Autoren sind bedeutende Fachleute der deutschen Automobil- und Zuliefererindustrie, sie stellen sicher, dass Theorie und Praxis vernetzt vermittelt werden. Die dritte Auflage wurde neu bearbeitet, aktualisiert und erweitert. Damit haben die aktuellen Entwicklungen von Benzindirekteinspritzung und variabler Ventilbetrieb, sowie Partikelfilter, Doppelkupplungsgetriebe, ESP-Plus, SUN-Fuel oder variable adaptive Beleuchtungssysteme Eingang gefunden. Neu aufgenommen wurden Abschnitte zu Normung (z.B. Telematik und Schnittstellenfragen), Unfallforschung, Innenausstattung, Software, kundendienstgerechte Konstruktion, Instandhaltung und Diagnose sowie zu Wettbewerbs/Rennfahrzeugen. Aus dem Inhalt: Anforderungen an Automobile - Innovative Technologien - Aerodynamik - Klimatisierung - Akustik - Design - Package - Brennstoffzelle - Elektrofahrzeug - Gasturbine - Ottomotor - Dieselmotor - Aufladesysteme - Getriebe und Kupplung - Allrad - Bremsen und Regelsysteme - Zweitakter - Karosseriebauweisen - Materialien - Oberflaechenschutz - Fahrzeuginnenraum - Fahrzeugsicherheit - Bremsen - Reifen - Fahrwerkauslegung - Kraftstoffe - Elektrik/Elektronik - Software - Fahrerassistenzsysteme - Beleuchtung - Sensorik - Bordnetz - EMV - Werkstoffe - Simultaneous Engineering - Simulationstechnik - Versuchstechnik - Automobil und Verkehr der Zukunft - Gesetzgebung und Normen - Unfallforschung - Diagnose und Instandhaltung - Rennsportwagen (orig.)

  15. Diagnostic imaging of the hand. 3. rev. and enl. ed.; Bildgebende Diagnostik der Hand

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, Rainer [Herz und Gefaessklinik GmbH, Bad Neustadt (Germany). Klinik fuer Diagnostische und Interventionelle Radiologie; Lanz, Ulrich

    2015-07-01

    The book on diagnostic imaging of the hand covers the following issues: projection radiography, cinematography, MRT and CR arthrography, arthroscopy, arteriography, skeleton scintiscanning, sonography, computerized tomography, magnetic resonance tomography, anatomy of forearm and carpus, anatomy of metacarpus and fingers, carpal function and morphometry, postoperative X-ray diagnostic, growing hand skeleton, normative variants, malformations and deformities, trauma of the distal forearm, lesions of the ulnocarpal complex (TFCC), scaphoid fractures, scaphoid arthrosis, fractures of other carpus bones, carpal luxations and luxation fractures, carpal instabilities, fractures of the metacarpalla, finger fractures, arthrosis deformans, enthesiopathies, sport induced soft tissue lesions, osteonecrosis, impingement syndromes, osteopenic skeletal diseases, metabolis diseases, crystal-induced osteoarthropaties, rheumatoid arthritis, spondyloarthritis, rheumatic fever, collagenoses, infective arthritis, osteomyelitis, soft tissue infections, cystoids bone lesions, skeletal tumors, soft tissue tumors, carpal tunnel syndrome, nerve compression syndrome, arterial perfusion disturbances, differential diagnostic tables on hand lesions.

  16. Combined scintigraphic and radiographic diagnosis of bone and joint diseases. 3. rev. and enl. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Bahk, Yong-Whee [Sung Ae General Hospital, Seoul (Korea). Dept. of Nuclear Medicine and Radiology

    2007-07-01

    The third edition of Combined Scintigraphic and Radiographic Diagnosis of Bone and Joint Diseases has been comprehensively rewritten and rearranged. It now encompasses, in addition to the bone and joint diseases described in the two earlier editions, hitherto unpublished novel applications of pinhole scanning to the diagnosis of a broader spectrum of skeletal disorders than ever before, including those of the soft tissues. A large number of state-of-the-art scans and corroboratory images obtained using CT, MRI and/or sonography are presented side by side. The book has been considerably expanded to discuss five new themes: Normal Variants and Artifacts, Drug-Induced Osteoporosis, Soft-Tissue Tumors and Tumor-like Conditions, PET/CT in Bone and Joint Diseases and A Genetic Consideration of Skeletal Disorders. Topical chapters on rheumatic skeletal disorders, malignant tumors of bone, benign tumors of bone and traumatic diseases have also been thoroughly rewritten and are complemented by the addition of some 90 recently acquired cases. (orig.)

  17. MRT of the central nervous system. 2. rev. and enl. ed.; MRT des Zentralnervensystems

    Energy Technology Data Exchange (ETDEWEB)

    Forsting, Michael [Universitaetsklinikum Essen (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie und Neuroradiologie; Jansen, Olav (ed.) [Universitaetsklinikum Schleswig-Holstein, Kiel (Germany). Klinik fuer Radiologie und Neuroradiologie

    2014-11-01

    The book on MRT of the central nervous system includes the following chapters: anatomy, vascular diseases, brain tumors, craniocerebral injuries, infectious diseases, multiple sclerosis and related diseases, metabolic diseases, degenerative diseases, malformations and developmental disorders, hydrocephalus and intracranial hypertension, spinal marrow, degenerative caused spinal and foraminal stenosis, traumata, tumors and tumor-like neoplasm, vascular diseases, inflammations, infections and related diseases, diseases of the peripheral nervous system.

  18. Radiology trainer. Surgical ambulance. 2. rev. and enl. ed.; Roentgen-Trainer. Chirurgische Ambulanz

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, Ole [Wedau-Kliniken Duisburg (Germany). Klinik fuer Unfallchirurgie; Ruchholtz, Steffen [Universitaetsklinikum Giessen und Marburg GmbH, Marburg (Germany). Klinik fuer Unfall-, Hand- und Wiederherstellungschirurgie; Siemann, Holger [LVR Klinikum Essen (Germany); Barkhausen, Joerg [Universitaetsklinikum Schleswig-Holstein, Luebeck (Germany). Klinik fuer Radiologie und Nuklearmedizin

    2013-08-01

    The radiology trainer for surgical ambulance includes informative X-ray imaging examples for the following issues: zygoma, nasal bone, spinal cord, clavicle, shoulder, upper arms, elbow, forearms, wrist, hand, phalanx, thorax, sternum, pelvis, abdomen, hips, femur, knee, lower leg, ankle, feet.

  19. EEG. Renewables Act. Comment. 3. new rev. and enl. ed.; EEG. Erneuerbare-Energien-Gesetz. Kommentar

    Energy Technology Data Exchange (ETDEWEB)

    Frenz, Walter [Rheinisch-Westfaelische Technische Hochschule (RWTH), Aachen (Germany). Lehr- und Forschungsgebiet Berg-, Umwelt- und Europarecht; Mueggenborg, Hans-Juergen (eds.) [Kassel Univ. (Germany)

    2013-05-01

    Like hardly any other law, the Renewable Energy Sources Law (EEG) is a subject to continuing modifications. This makes the application of the already complicated regulations even for experts to a special challenge. With the proven Berliner comment EEG, now a reliable companion through the bureaucratic jungle is available. All regulations of the EEG are commented precisely and easily to understand by profound experts. An extensive selection of terminology enables a rapid orientation within this book. In addition to the excursions to renewable energy technologies, this book also describes the structural aspects in the establishment of a photovoltaic system.

  20. Dictionary of power engineering and automation. Pt. 2. 3. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Bezner, H.

    1993-01-01

    This dictionary essentially covers the following subjects: Basic electrotechnical terms and standards; Electrical machines (including transformers); Switchgear; Electrical systems and networks; Electrical installation practice (including lighting); Power cables; Power electronics; Protective devices and relays; Electrical measuring and analysis technology; Telecontrol; Automotive electronics; Semiconductor devices, integrated circuits; Automation technology (control engineering, programmable and numerical controls, process control); Bus systems, communication networks, data transmission and communication; Test engineering; Quality assurance and reliability. (orig./HP) [de

  1. Doppler ultrasound in obstetrics and gynecology. 2. rev. and enl. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Maulik, D. [Winthrop Univ. Hospital, Mineola, NY (United States). Dept. of Obstetrics and Gynecology; Zalud, I. (eds.) [Kapiolani Medical Center for Women and Children, Honolulu, HI (United States)

    2005-07-01

    The second edition of Doppler Ultrasound in Obstetrics and Gynecology has been expanded and comprehensively updated to present the current standards of practice in Doppler ultrasound and the most recent developments in the technology. Doppler Ultrasound in Obstetrics and Gynecology encompasses the full spectrum of clinical applications of Doppler ultrasound for the practicing obstetrician-gynecologist, including the latest advances in 3D and color Doppler and the newest techniques in 4D fetal echocardiography. Written by preeminent experts in the field, the book covers the basic and physical principles of Doppler ultrasound; the use of Doppler for fetal examination, including fetal cerebral circulation; Doppler echocardiography of the fetal heart; and the use of Doppler for postdated pregnancy and in cases of multiple gestation. Chapters on the use of Doppler for gynecologic investigation include ultrasound in ectopic pregnancy, for infertility, for benign disorders and for gynecologic malignancies. (orig.)

  2. Ordinance on the Carriage of Dangerous Goods by Rail (GGVE). 2. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Ridder, K.; Katholnig, F.

    1993-01-01

    The book presents the legislative texts and other legal provisions concerning the transport of dangerous goods by rail: (1) Act on the transport of dangerous goods, full text. (2) Ordinance on the carriage of dangerous goods by rail (GGVE) - GGVE skeleton ordinance; Annex to the skeleton ordinance. (3) Documents - GGVE implementing regulations RE 001; R 002; Ordinance on exeptions GGVE; Extracts from IAEA recommendations concerning safe transport of radioactive materials; catalogue of fines pertaining to section 10 GGVE. (4) Alphabetical list of materials for GGVE/RID and GGVS/ADR. Index terms printed in deep black at the margin of pages allow quick access to the text passages of interest, and there is a subject index for retrieval over the entire book. (orig./HP) [de

  3. Computed tomography of the head and spinal cord. 2. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Hosten, N.; Liebig, T.

    2007-01-01

    This is an everyday reference manual for routine diagnosis and also for critical situations; it is a reliable vademecum for all radiologists, neurologists and neurosurgeons. It contains all information that is required for CT diagnosis of the skull and spinal cord. Detailed information on normal anatomy and standard reference values enable the practician to differentiate between normal and pathological findings. There is a clear and didactically useful structure with sections on pathogenesis, clinical findings and CT morphology for each clinical picture. (orig.)

  4. MRT of the locomotor system. 4. rev. and enl. ed.; MRT des Bewegungsapparats

    Energy Technology Data Exchange (ETDEWEB)

    Vahlensieck, Martin [Praxisnetz Radiologie und Nuklearmedizin Bonn Bad Godesberg - RheinSieg, Bonn (Germany); Reiser, Maximilian (ed.) [Klinikum Grosshadern, Muenchen (Germany). Inst. fuer Klinische Radiologie

    2015-02-01

    The book on MRT of the locomotor system covers the following topics: relevant NMT imaging techniques, spinal cord, shoulder, elbows, wrist and fingers, hip region, knee, lower leg - ankle - foot, temporomandibular joint, skeletal muscles, bone marrow, bone and soft tissue tumors, osteoporosis, sacroiliac joint, jaw and periodontium.

  5. Differential diagnosis of rheumatic illnesses. 4. compl. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Zeidler, Henning; Michel, Beat

    2009-01-01

    The number of the possible differential diagnosis of rheumatic illnesses is extraordinarily high. This circumstance makes the diagnostics a difficult field with numerous pitfalls. The correct and complete diagnosis however is a condition for the correct therapy. This book facilitates this way from the symptom to the diagnosis for the reader: A detailed representation of the fundamentals (anamnesis, investigation findings, laboratory diagnostics and imaging) a detailed description of all important differential diagnosis follows. The meanwhile fourth edition of this standard work was completely revised and updated. An indispensable guide book for all persons which treat patients with rheumatic illnesses [de

  6. Diagnostic radiology of thoracic diseases. Textbook and atlas. 4. compl. rev. and enl. ed.

    International Nuclear Information System (INIS)

    Lange, Sebastian

    2010-01-01

    The book on diagnostic radiology of thoracic diseases covers the following topics: diagnostic techniques and normal diagnostic findings using x-ray radiography, CT, scintigraphy, angiography, bronchography, ultrasonography and NMR imaging; malformations; infections; emphysema, chronic lung diseases and asthma; inhalation damage and pneumoconiosis; neoplasm; vascular diseases; thorax injuries, pleura diseases, heart diseases, mediastinum diseases; midriff diseases; thoracic wall diseases; pathological pattern in CT; radiological indications and differential diagnostics; thoracic interventions.

  7. Manual for the energy trade. 3. new rev. and enl. ed.

    International Nuclear Information System (INIS)

    Schwintowski, Hans-Peter

    2014-01-01

    This manual sheds a light on the energy trade from both a legal and an empirical economic perspective. Its focus is on those business fields within the energy trade that are of foremost practical relevance, namely the OTC trade and the exchange trade. It also provides concise coverage of risk management systems in the energy trade along with a competent account of their implications with regard to supervisory regulations. In this, its third edition the manual addresses the latest developments in both the national and the international energy trade, including those seen in the gas storage market and its market access regulations; consideration is here also given to market transparency, market distortion and liquidity. The commentary on standard contracts (EFET) has been updated. The manual also addresses the adaptations made in the minimum requirements for risk management.

  8. Time scale in quasifission reactions

    Energy Technology Data Exchange (ETDEWEB)

    Back, B.B.; Paul, P.; Nestler, J. [and others

    1995-08-01

    The quasifission process arises from the hindrance of the complete fusion process when heavy-ion beams are used. The strong dissipation in the system tends to prevent fusion and lead the system towards reseparation into two final products of similar mass reminiscent of a fission process. This dissipation slows down the mass transfer and shape transformation and allows for the emission of high energy {gamma}-rays during the process, albeit with a low probability. Giant Dipole {gamma} rays emitted during this time have a characteristic spectral shape and may thus be discerned in the presence of a background of {gamma} rays emitted from the final fission-like fragments. Since the rate of GDR {gamma} emission is very well established, the strength of this component may therefore be used to measure the timescale of the quasifission process. In this experiment we studied the reaction between 368-MeV {sup 58}Ni and a {sup 165}Ho target, where deep inelastic scattering and quasifission processes are dominant. Coincidences between fission fragments (detected in four position-sensitive avalanche detectors) and high energy {gamma} rays (measured in a 10{close_quotes} x 10{close_quotes} actively shielded NaI detector) were registered. Beams were provided by the Stony Brook Superconducting Linac. The {gamma}-ray spectrum associated with deep inelastic scattering events is well reproduced by statistical cooling of projectile and target-like fragments with close to equal initial excitation energy sharing. The y spectrum associated with quasifission events is well described by statistical emission from the fission fragments alone, with only weak evidence for GDR emission from the mono-nucleus. A 1{sigma} limit of t{sub ss} < 11 x 10{sup -21} s is obtained for the mono-nucleus lifetime, which is consistent with the lifetime obtained from quasifission fragment angular distributions. A manuscript was accepted for publication.

  9. Intermediate processes in nuclear reactions

    International Nuclear Information System (INIS)

    Petrovici, M.

    1983-01-01

    The main results presented here cannot be interpreted in terms of the direct reaction model or the statistical models and one can more or less explicitely use some nuclear configurations for their interpretation. The first chapter deals with the so-called second order intermediate structures observed in the elastic and inelastic proton scattering on 66 Zn and 70 Ge targets in the energetic regions of some isobaric analog resonances. A formal theory for their interpretation is developed and the comparison with the experimental data is presented. New experimental results on the resonant structures observed in the elastic and inelastic scattering of 12 C on 24 Mg are presented in the second chapter. Detailed statistical analysis and their interpretation is presented too. Charge equilibration in deep inelastic collisions is the main subject of the third chapter. The experimental results obtained by the 98 Mo + 154 Sm collision at 12 MeV/n, a quantum treatment of a damped harmonic oscillator and the comparison with the experimental data are given. In the last chapter, some results on the existence of two other processes which could candidate to be involved in the main topic are presented. Those processes are: the fast fragmentation and preequilibrium charged particles emission. All these processes originate in the excitation of some simple configurations which can be seen on ''doorway'' states (''Hallway'' in the case of the second intermediate structures). The coupling of these states to other more complicated excitation modes of the nuclei and to outgoing channel=gives the possibility to study the nuclear dynamics. This justifies the interest for their detailed theoretical and experimental investigations. (author)

  10. Evaluation of periprocedural hypersensitivity reactions.

    Science.gov (United States)

    Iammatteo, Melissa; Keskin, Taha; Jerschow, Elina

    2017-10-01

    Identifying the cause of periprocedural hypersensitivity reactions (HSRs) remains challenging because of the multitude of medications involved. Antibiotics are the most common cause in the United States, whereas neuromuscular blocking agents are most common in Europe. To identify causative agents for periprocedural HSRs. This study was a 7-year retrospective medical record review of patients evaluated between December 2009 and January 2017 at a drug allergy center in Bronx, New York for periprocedural HSRs, defined as occurring soon before, during, or soon after a medical procedure or operation with or without general anesthesia. Demographics, description of historical HSRs, results of testing to potential causative medications, and tolerance of subsequent anesthesia were reviewed. Thirty-four patients completed a comprehensive evaluation. Skin testing identified an IgE-mediated cause in 22 patients (64.7%). The most common causative class of medications was induction agents (n = 9 [36%]), with midazolam being the most frequently implicated (n = 6 [3 positive skin test results, 3 equivocal skin test results]). Cefazolin was the most common agent identified (n = 8 [32%]) followed by ondansetron (n = 3 [12%]). Sixteen of 22 contacted patients were exposed to subsequent anesthesia, including 3 patients with negative evaluations. One patient experienced a mild urticarial HSR. Induction agents were the most common causative agents in our patients, which differs from other studies. Given the variability in evaluations of periprocedural HSRs across the United States with data published on small sample sizes, there is a need to establish national guidelines to standardize evaluations and to create a national registry to allow for data sharing. Copyright © 2017 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  11. Catalytic Hydrogenation Reaction of Naringin-Chalcone. Study of the Electrochemical Reaction

    Directory of Open Access Journals (Sweden)

    B. A. López de Mishima

    2000-03-01

    Full Text Available The electrocatalytic hydrogenation reaction of naringin derivated chalcone is studied. The reaction is carried out with different catalysts in order to compare with the classic catalytic hydrogenation.

  12. Entity models for trigger-reaction documents

    NARCIS (Netherlands)

    Khalid, M.A.; Marx, M.; Makkes, M.X.

    2008-01-01

    We define the notion of an entity model for a special kind of document popular on the web: an article followed by a list of reactions on that article, usually by many authors, usually inverse chronologically ordered. We call these documents trigger-reactions pairs. The entity model describes which

  13. Reaction between drug substances and pharmaceutical excipients

    DEFF Research Database (Denmark)

    Larsen, Jesper; Cornett, Claus; Jaroszewski, Jerzy Witold

    2009-01-01

    The reactivity of citric acid towards drug substances in the solid state was examined using the beta-blocker carvedilol as a model compound. The reaction mixtures were analysed by LC-MS, the reaction products were isolated by preparative HPLC, and the structures were elucidated by microprobe NMR...

  14. Enantioselective solvent-free Robinson annulation reactions

    Indian Academy of Sciences (India)

    Unknown

    asymmetric annulation reactions in a solid–liquid phase reaction in the absence of solvents to effect an asymmetric synthesis is an important step forward towards cleaner synthesis 2. Environmental and economic pressures are now forcing the chemical community to search for more efficient ways of performing chemical ...

  15. Reactions to Stranger and Acquaintance Rape.

    Science.gov (United States)

    Tetreault, Patricia A.; Barnett, Mark A.

    1987-01-01

    Investigated reactions to a woman who presumably had been raped by a stranger or an acquaintance. Undergraduates read one of two rape descriptions prior to watching a videotape of the woman who (they were led to believe) had been the victim of the rape. Females and males showed markedly different reactions to stranger and acquaintance rape and…

  16. Rape: The Husband's and Boyfriend's Intital Reactions.

    Science.gov (United States)

    Holmstrom, Lynda Lytle; Burgess, Wolbert

    1979-01-01

    Analyzes the reaction of husbands and boyfriends to the rape of a wife or girlfriend. The man's reaction has two components: his own response and his interaction with the victim. The issues are whether the couple can discuss the rape, deal with the woman's new phobias, and resume sexual relations. (Author)

  17. The Theory of Absolute Reaction Rates

    Indian Academy of Sciences (India)

    Admin

    ... theory overcame all obstacles and is presently the most successful theory for chemical reactions. The Classic in this issue is the paper by Eyring, presented at this meeting. It summarizes the contributions of his group till that date, and is one of the most important papers in the theory of chemical reactions. K L Sebastian ...

  18. Review of fungus-induced asthmatic reactions

    NARCIS (Netherlands)

    Kauffman, H. F.; TOMEE, J. F.; van der Werf, T. S.; de Monchy, J. G.; Koëter, G. K.

    Fungus-induced obstructive airway disease in atopic individuals can be differentiated into two categories: first, uncomplicated asthmatic reactions due to high but transient exposure to fungal spores (fungal asthma), resulting in a T-H2-type response with immunoglobulin E-mediated reactions and

  19. Femtosecond laser control of chemical reactions

    CSIR Research Space (South Africa)

    Du Plessis, A

    2010-08-31

    Full Text Available Femtosecond laser control of chemical reactions is made possible through the use of pulse-shaping techniques coupled to a learning algorithm feedback loop – teaching the laser pulse to control the chemical reaction. This can result in controllable...

  20. Rebinding in biochemical reactions on membranes

    Science.gov (United States)

    Lawley, Sean D.; Keener, James P.

    2017-10-01

    The behavior of many biochemical processes depends crucially on molecules rapidly rebinding after dissociating. In the case of multisite protein modification, the importance of rebinding has been demonstrated both experimentally and through several recent computational studies involving stochastic spatial simulations. As rebinding stems from spatio-temporal correlations, theorists have resorted to models that explicitly include space to properly account for the effects of rebinding. However, for reactions in three space dimensions it was recently shown that well-mixed ordinary differential equation (ODE) models can incorporate rebinding by adding connections to the reaction network. The rate constants for these new connections involve the probability that a pair of molecules rapidly rebinds after dissociation. In order to study biochemical reactions on membranes, in this paper we derive an explicit formula for this rebinding probability for reactions in two space dimensions. We show that ODE models can use the formula to replicate detailed stochastic spatial simulations, and that the formula can predict ultrasensitivity for reactions involving multisite modification of membrane-bound proteins. Further, we compute a new concentration-dependent rebinding probability for reactions in three space dimensions. Our analysis predicts that rebinding plays a much larger role in reactions on membranes compared to reactions in cytoplasm.

  1. Strategies for Innovation in Multicomponent Reaction Design

    OpenAIRE

    Ganem, Bruce

    2009-01-01

    By generating structural complexity in a single step from three or more reactants, multicomponent reactions (MCRs) make it possible to synthesize target compounds with greater efficiency and atom economy. The history of such reactions can be traced to the mid-nineteenth century when Strecker first produced α-aminonitriles from the condensation of aldehydes with ammonia and hydrogen cyanide.

  2. Multicomponent Reactions, Union of MCRs and Beyond

    NARCIS (Netherlands)

    Zarganes-Tzitzikas, Tryfon; Chandgude, Ajay L; Dömling, Alexander

    2015-01-01

    Multicomponent reactions (MCRs), which are located between one- and two-component and polymerization reactions, provide a number of valuable conceptual and synthetic advantages over stepwise sequential approaches towards complex and valuable molecules. To address current limitations in the number of

  3. Analytical Study of Thermonuclear Reaction Probability Integrals

    OpenAIRE

    Chaudhry, M. A.; Haubold, H. J.; Mathai, A. M.

    2000-01-01

    An analytic study of the reaction probability integrals corresponding to the various forms of the slowly varying cross-section factor $S(E)$ is attempted. Exact expressions for reaction probability integrals are expressed in terms of the extended gamma functions.

  4. Parity violation in neutron induced reactions

    International Nuclear Information System (INIS)

    Gudkov, V.P.

    1991-06-01

    The theory of parity violation in neutron induced reactions is discussed. Special attention is paid to the energy dependence and enhancement factors for the various types of nuclear reactions and the information which might be obtained from P-violating effects in nuclei. (author)

  5. Immune reactions in classical Hodgkin's lymphoma

    NARCIS (Netherlands)

    Poppema, S; Potters, M; Emmens, R; Visser, L; van den Berg, A.

    The immune reaction in classical Hodgkin's lymphoma (HL) can be separated into an inflammatory response in the involved tissues and a generalized immune response in the patient. The local immune reaction in HL is by far the most prominent among all tumors, with the exception of so called T-cell-rich

  6. Chemical Reaction: Diagnosis and Towards Remedy of ...

    African Journals Online (AJOL)

    Experience and literature show that most high school students do not have the correct mental models of coefficients and subscripts in chemical reactions. To contribute towards the conceptual reconstruction of scientific mental models of coefficients and subscripts in a chemical reaction a new teaching-learning strategy is ...

  7. reactions of enolisable ketones with dichloroisocyanuric acid

    African Journals Online (AJOL)

    B. S. Chandravanshi

    1Department of Chemistry, TJPS (PG) College, Guntur-522006, India .... Reactions of enolisable ketones with dichloroisocyanuric acid. Bull. Chem. Soc. Ethiop. 2015, 29(1). 131. Figure 2. Plots for first order dependence on oxidant (in ..... Subba Rao, T.L.M.V. Study of chemical dynamics of some oxidation reactions, Ph.D.

  8. Potential energy surfaces for chemical reactions

    International Nuclear Information System (INIS)

    Schaefer, H.F. III.

    1976-01-01

    Research into potential energy surfaces for chemical reactions at Lawrence Berkeley Laboratory during 1976 is described. Topics covered include: the fuzzy interface between surface chemistry catalysis and organometallic chemistry; potential energy surfaces for elementary fluorine hydrogen reactions; structure, energetics, and reactivity of carbenes; and the theory of self-consistent electron pairs

  9. Spallation reactions studied with 4-detector arrays

    Indian Academy of Sciences (India)

    Recently there has been a renewed interest in the study of spallation reactions in basic nuclear physics as well as in potential applications. Spallation reactions induced by light projectiles (protons, antiprotons, pions, etc.) in the GeV range allow the formation of hot nuclei which do not suffer the collective excitations ...

  10. Heavy ion reactions at low energies

    International Nuclear Information System (INIS)

    Nemes, M.C.

    1985-01-01

    Some general features of the heavy ion reactions at low energies are presented. Some kinds of processes are studied, such as: elastic scattering, peripherical reactions, deep inelastic collisions and fusion. Both, theoretical and experimental perspectives on this field are discussed. (L.C.) [pt

  11. Adverse reactions to intravascularly administered contrast media

    International Nuclear Information System (INIS)

    Olin, T.

    1986-01-01

    A hypothesis is formulated about the mechanisms causing adverse reactions to contrast media. Contrast media act in two ways. They stimulate the mast cells to release histamine and leukotrienes, and they inhibit the enzymes which otherwise degrade leukotrienes. Thus individuals, especially those with a history of allergy, are easily exposed to undue amounts of leukotrienes and these are responsible for the adverse reactions. (orig.)

  12. Multicomponent modelling of Portland cement hydration reactions

    NARCIS (Netherlands)

    Ukrainczyk, N.; Koenders, E.A.B.; Van Breugel, K.

    2012-01-01

    The prospect of cement and concrete technologies depends on more in depth understanding of cement hydration reactions. Hydration reaction models simulate the development of the microstructures that can finally be used to estimate the cement based material properties that influence performance and

  13. Chemical reaction due to stronger Ramachandran interaction

    Indian Academy of Sciences (India)

    fulfilling this condition, these atoms still need to have an overall strong attractive interaction (either before or after the collision) to form the required transition state. For example, the transition state by definition gives equal probability for the reaction to go either way (to form reactant atoms, or the reaction product). There-.

  14. Organotellurium ligands–designing and complexation reactions

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 114; Issue 4. Organotellurium ligands - designing and complexation reactions. Ajai K Singh. Volume 114 Issue 4 August ... A variety of tellurium ligands has been designed and studied for their complexation reactions in the last decade. Of these hybrid telluroethers, ...

  15. Reactions the private life of atoms

    CERN Document Server

    Atkins, Peter

    2011-01-01

    Through an innovative, closely integrated design of images and text, and his characteristically clear, precise, and economical exposition, Peter Atkins explains the processes involved in chemical reactions. He begins by introducing a 'tool kit' of basic reactions, such as precipitation, corrosion, and catalysis, and concludes by showing how these building blocks are brought together in more complex processes such as photosynthesis.

  16. Heavy ion transfer reactions: Status and perspectives

    Indian Academy of Sciences (India)

    Abstract. With the large solid angle magnetic spectrometer (PRISMA) coupled to the γ-array (CLARA), extensive investigations of nuclear structure and reaction dynamics have been carried out. In the present paper aspects of these studies will be presented, focussing more closely on the reaction mechanism, in particular on ...

  17. Hydrazine in the Ugi Tetrazole Reaction

    NARCIS (Netherlands)

    Patil, Pravin; Zhang, Ji; Kurpiewska, Katarzyna; Kalinowska-Tłuścik, Justyna; Dömling, Alexander

    2016-01-01

    We describe the hitherto unknown use of N-Boc-protected hydrazine in the Ugi tetrazole reaction to access a library of highly substituted 5-(hydrazinomethyl)-1-methyl-1H-tetrazoles. The reaction is very versatile and good to high yielding. A one-pot, two-step procedure is given.

  18. Entropy Generation in a Chemical Reaction

    Science.gov (United States)

    Miranda, E. N.

    2010-01-01

    Entropy generation in a chemical reaction is analysed without using the general formalism of non-equilibrium thermodynamics at a level adequate for advanced undergraduates. In a first approach to the problem, the phenomenological kinetic equation of an elementary first-order reaction is used to show that entropy production is always positive. A…

  19. Use of Isotopes for Studying Reaction Mechanisms

    Indian Academy of Sciences (India)

    applications of isotopic substitution for studying reaction mechanisms and dynamic structures. Suggested Reading. • B K Carpenter. Determination of Organic Reaction Mechanisms. John. Wiley. New York, 1984. • F A Carey and R J Sundberg. Advanced Organic Chemistry. Part A. 3rd. Ed. Plenum Press. New York, 1990.

  20. Infliximab-Related Infusion Reactions: Systematic Review

    Science.gov (United States)

    Ron, Yulia; Kivity, Shmuel; Ben-Horin, Shomron; Israeli, Eran; Fraser, Gerald M.; Dotan, Iris; Chowers, Yehuda; Confino-Cohen, Ronit; Weiss, Batia

    2015-01-01

    Objective: Administration of infliximab is associated with a well-recognised risk of infusion reactions. Lack of a mechanism-based rationale for their prevention, and absence of adequate and well-controlled studies, has led to the use of diverse empirical administration protocols. The aim of this study is to perform a systematic review of the evidence behind the strategies for preventing infusion reactions to infliximab, and for controlling the reactions once they occur. Methods: We conducted extensive search of electronic databases of MEDLINE [PubMed] for reports that communicate various aspects of infusion reactions to infliximab in IBD patients. Results: We examined full texts of 105 potentially eligible articles. No randomised controlled trials that pre-defined infusion reaction as a primary outcome were found. Three RCTs evaluated infusion reactions as a secondary outcome; another four RCTs included infusion reactions in the safety evaluation analysis; and 62 additional studies focused on various aspects of mechanism/s, risk, primary and secondary preventive measures, and management algorithms. Seven studies were added by a manual search of reference lists of the relevant articles. A total of 76 original studies were included in quantitative analysis of the existing strategies. Conclusions: There is still paucity of systematic and controlled data on the risk, prevention, and management of infusion reactions to infliximab. We present working algorithms based on systematic and extensive review of the available data. More randomised controlled trials are needed in order to investigate the efficacy of the proposed preventive and management algorithms. PMID:26092578

  1. Catalysis and Multi-Component Reactions

    Science.gov (United States)

    Shibasaki, Masakatsu; Yus, Miguel; Bremner, Stacy; Comer, Eamon; Shore, Gjergji; Morin, Sylvie; Organ, Michael G.; van der Eycken, Erik; Merkul, Eugen; Dorsch, Dieter; Müller, Thomas J. J.; Ryabukhin, Sergey V.; Ostapchuk, Eugeniy N.; Plaskon, Andrey S.; Volochnyuk, Dmitriy M.; Shivanyuk, Alexander N.; Tolmachev, Andrey A.; Sheibani, Hassan; Babaie, Maryam; Behzadi, Soheila; Dabiri, Minoo; Bahramnejad, Mahboobeh; Bashiribod, Sahareh; Hekmatshoar, Rahim; Sadjadi, Sodeh; Khorasani, Mohammad; Polyakov, Anatoliy I.; Eryomina, Vera A.; Medvedeva, Lidiya A.; Tihonova, Nadezhda I.; Listratova, Anna V.; Voskressensky, Leonid G.; Merkul, Eugen; Dorsch, Dieter; Müller, Thomas J. J.; Sheibani, Hassan; Esfandiarpoor, Zeinab; Behzadi, Soheila; Titova, Julia A.; Fedorova, Olga V.; Ovchinnikova, Irina G.; Valova, Marina S.; Koryakova, Olga V.; Rusinov, Gennady L.; Charushin, Valery N.; Hekmatshoar, Rahim; Sadjadi, Sodeh

    We have been studying the development of new asymmetric two-center catalysis using rare earth alkoxides and bifunctional sugar and related ligands. In The Fourth International Conference on Multi-Component Reactions and Related Chemistry (MCR 2009), new catalytic asymmetric reactions using catalysts 1 and 2 and catalytic asymmetric syntheses of ranirestat 3 and tamiflu 4 will be presented.

  2. Chemical Principles Revisited: Annotating Reaction Equations.

    Science.gov (United States)

    Tykodi, R. J.

    1987-01-01

    Urges chemistry teachers to have students annotate the chemical reactions in aqueous-solutions that they see in their textbooks and witness in the laboratory. Suggests this will help students recognize the reaction type more readily. Examples are given for gas formation, precipitate formation, redox interaction, acid-base interaction, and…

  3. TRIMOLECULAR REACTIONS OF URANIUM HEXAFLUORIDE WITH WATER

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, M.; Becnel, J.; Garrison, S.

    2010-02-25

    The hydrolysis reaction of uranium hexafluoride (UF{sub 6}) is a key step in the synthesis of uranium dioxide (UO{sub 2}) powder for nuclear fuels. Mechanisms for the hydrolysis reactions are studied here with density functional theory and the Stuttgart small-core scalar relativistic pseudopotential and associated basis set for uranium. The reaction of a single UF{sub 6} molecule with a water molecule in the gas phase has been previously predicted to proceed over a relatively sizeable barrier of 78.2 kJ {center_dot} mol{sup -1}, indicating this reaction is only feasible at elevated temperatures. Given the observed formation of a second morphology for the UO{sub 2} product coupled with the observations of rapid, spontaneous hydrolysis at ambient conditions, an alternate reaction pathway must exist. In the present work, two trimolecular hydrolysis mechanisms are studied with density functional theory: (1) the reaction between two UF{sub 6} molecules and one water molecule, and (2) the reaction of two water molecules with a single UF{sub 6} molecule. The predicted reaction of two UF{sub 6} molecules with one water molecule displays an interesting 'fluorine-shuttle' mechanism, a significant energy barrier of 69.0 kJ {center_dot} mol{sup -1} to the formation of UF{sub 5}OH, and an enthalpy of reaction ({Delta}H{sub 298}) of +17.9 kJ {center_dot} mol{sup -1}. The reaction of a single UF{sub 6} molecule with two water molecules displays a 'proton-shuttle' mechanism, and is more favorable, having a slightly lower computed energy barrier of 58.9 kJ {center_dot} mol{sup -1} and an exothermic enthalpy of reaction ({Delta}H{sub 298}) of -13.9 kJ {center_dot} mol{sup -1}. The exothermic nature of the overall UF{sub 6} + 2 {center_dot} H{sub 2}O trimolecular reaction and the lowering of the barrier height with respect to the bimolecular reaction are encouraging; however, the sizable energy barrier indicates further study of the UF{sub 6} hydrolysis reaction

  4. Selective immediate hypersensitivity reactions to NSAIDs.

    Science.gov (United States)

    Canto, Maria Gabriela; Andreu, Isabel; Fernandez, Javier; Blanca, Miguel

    2009-08-01

    Selective immediate reactions to NSAIDs imply that patients develop a urticarial/anaphylactic response to a single drug with good tolerance to other compounds. No systematic review of these reactions has yet been made. With the increase in consumption of NSAIDs, these have become one of the most common drugs inducing hypersensitivity reactions. Although cross-intolerance reactions are the most common, a significant proportion is selective responses. As specific IgE antibodies are not always found, there is only indirect evidence supporting an IgE-mediated mechanism in selective NSAID reactors. Selective immediate reactions to NSAIDs must be considered when a patient develops urticaria or anaphylaxis after intake of one drug with good tolerance to drugs from other groups or even a drug from the same group with a slightly different chemical structure. Further research is required to identify the antigenic determinant structures recognized.

  5. Constituent models and large transverse momentum reactions

    International Nuclear Information System (INIS)

    Brodsky, S.J.

    1975-01-01

    The discussion of constituent models and large transverse momentum reactions includes the structure of hard scattering models, dimensional counting rules for large transverse momentum reactions, dimensional counting and exclusive processes, the deuteron form factor, applications to inclusive reactions, predictions for meson and photon beams, the charge-cubed test for the e/sup +-/p → e/sup +-/γX asymmetry, the quasi-elastic peak in inclusive hadronic reactions, correlations, and the multiplicity bump at large transverse momentum. Also covered are the partition method for bound state calculations, proofs of dimensional counting, minimal neutralization and quark--quark scattering, the development of the constituent interchange model, and the A dependence of high transverse momentum reactions

  6. Catalytic Conia-ene and related reactions.

    Science.gov (United States)

    Hack, Daniel; Blümel, Marcus; Chauhan, Pankaj; Philipps, Arne R; Enders, Dieter

    2015-10-07

    Since its initial inception, the Conia-ene reaction, known as the intramolecular addition of enols to alkynes or alkenes, has experienced a tremendous development and appealing catalytic protocols have emerged. This review fathoms the underlying mechanistic principles rationalizing how substrate design, substrate activation, and the nature of the catalyst work hand in hand for the efficient synthesis of carbocycles and heterocycles at mild reaction conditions. Nowadays, Conia-ene reactions can be found as part of tandem reactions, and the road for asymmetric versions has already been paved. Based on their broad applicability, Conia-ene reactions have turned into a highly appreciated synthetic tool with impressive examples in natural product synthesis reported in recent years.

  7. Mechanisms of inorganic and organometallic reactions

    CERN Document Server

    The purpose of this series is to provide a continuing critical review of the literature concerned with mechanistic aspects of inorganic and organo­ metallic reactions in solution, with coverage being complete in each volume. The papers discussed are selected on the basis of relevance to the elucidation of reaction mechanisms and many include results of a nonkinetic nature when useful mechanistic information can be deduced. The period of literature covered by this volume is July 1982 through December 1983, and in some instances papers not available for inclusion in the previous volume are also included. Numerical results are usually reported in the units used by the original authors, except where data from different papers are com­ pared and conversion to common units is necessary. As in previous volumes material included covers the major areas of redox processes, reactions of the nonmetallic elements, reaction of inert and labile metal complexes and the reactions of organometallic compounds. While m...

  8. Low energy ion-molecule reactions

    Energy Technology Data Exchange (ETDEWEB)

    Farrar, J.M. [Univ. of Rochester, NY (United States)

    1993-12-01

    This project is concerned with elucidating the dynamics of elementary ion-molecule reactions at collision energies near and below 1 eV. From measurements of the angular and energy distributions of the reaction products, one can infer intimathe details about the nature of collisions leading to chemical reaction, the geometries and lifetimes of intermediate complexes that govern the reaction dynamics, and the collision energy dependence of these dynamical features. The author employs crossed-beam low energy mass spectrometry technology developed over the last several years, with the focus of current research on proton transfer and hydrogen atom transfer reactions of te O{sup {minus}} ion with species such as HF, H{sub 2}O, and NH{sub 3}.

  9. Snake antivenoms: adverse reactions and production technology

    Directory of Open Access Journals (Sweden)

    VM Morais

    2009-01-01

    Full Text Available Antivenoms have been widely used for more than a century for treating snakebites and other accidents with poisonous animals. Despite their efficacy, the use of heterologous antivenoms involves the possibility of adverse reactions due to activation of the immune system. In this paper, alternatives for antivenom production already in use were evaluated in light of their ability to minimize the occurrence of adverse reactions. These effects were classified according to their molecular mechanism as: anaphylactic reactions mediated by IgE, anaphylactoid reactions caused by complement system activation, and pyrogenic reactions produced mainly by the presence of endotoxins in the final product. In the future, antivenoms may be replaced by humanized antibodies, specific neutralizing compounds or vaccination. Meanwhile, improvements in antivenom quality will be focused on the obtainment of a more purified and specific product in compliance with good manufacturing practices and at an affordable cost.

  10. Intramolecular and Transannular Diels-Alder Reactions

    DEFF Research Database (Denmark)

    Tanner, David Ackland; Ascic, Erhad

    2014-01-01

    Few reactions can compete with the Diels-Alder (DA) [4+2] cycloaddition for the rapid and efficient generation of molecular complexity. The DA reaction is atom-economic and stereospecific, as well as diastereo- and regioselective. The intramolecular version (IMDA) of the DA cycloaddition and its...... and dienophile, methods for acceleration of IMDA reactions (such as use of high pressure) and catalysis (using oxophilic or carbophilic metal complexes, Brønsted acids, and enzymes). The use of furans as diene components (IMDAF), intramolecular hetero-DA (IMHDA) and IMDA reactions with inverse electron demand...... are also covered. Applications of IMDA to asymmetric synthesis (from substrate control through to enantioselective catalysis, including organocatalysis) are presented, along with tandem sequences involving IMDA cycloaddition. A theme pervading the whole chapter is the use of IMDA reactions for the total...

  11. Nature-Inspired Chemical Reaction Optimisation Algorithms.

    Science.gov (United States)

    Siddique, Nazmul; Adeli, Hojjat

    2017-01-01

    Nature-inspired meta-heuristic algorithms have dominated the scientific literature in the areas of machine learning and cognitive computing paradigm in the last three decades. Chemical reaction optimisation (CRO) is a population-based meta-heuristic algorithm based on the principles of chemical reaction. A chemical reaction is seen as a process of transforming the reactants (or molecules) through a sequence of reactions into products. This process of transformation is implemented in the CRO algorithm to solve optimisation problems. This article starts with an overview of the chemical reactions and how it is applied to the optimisation problem. A review of CRO and its variants is presented in the paper. Guidelines from the literature on the effective choice of CRO parameters for solution of optimisation problems are summarised.

  12. Ultracold 4-center reactions of KRb molecules

    Science.gov (United States)

    Hu, Ming-Guang; Liu, Yu; Gheorghe, Andrei; Lin, Yen-Wei; Ni, Kang-Kuen

    2017-04-01

    Chemical reactions at the fundamental level obey the laws of quantum mechanics. However, reactions are often far from the regime where the quantum motions of the reagents play an important role. Ultracold reactions of KRb is a good candidate, where the unusual 4-center reactions between two KRb molecules is expected to produce K2 and Rb2 molecules with 10 cm-1 (or 14.4 K) excess energy. To directly measure reaction products and to fully map out their quantum states, we are designing and constructing a novel quantum degenerate gas apparatus with the integration of REMPI and ion velocity mapping imaging. Our work aims to open up new directions for physical chemistry studies with AMO techniques.

  13. [Allergic reaction during anesthesia: two case reports].

    Science.gov (United States)

    Okamoto, Shinji; Futagawa, Koichi; Sugiura, Junko; Uchida, Tomohisa; Okuda, Takahiko; Koga, Yoshihisa

    2009-10-01

    We experienced two cases of serious and potentially life-threatening allergic reactions. The first patient was a 28-year-old male patient scheduled for surgery for cerebral arteriovenous malformations and another patient was a 66-year-old male patient scheduled for hepatic resection. After uneventful anesthetic induction, anesthesia was maintained with sevoflurane, air and oxygen. Both patients developed allergic reactions characterized by cardiovascular failure during anesthesia. Resuscitative treatment included rapid fluid infusion, administration of adrenaline and steroid. Both patients were successfully resuscitated without any lasting sequelae. The causative agent in one of these cases was probably a prophylactically used antibiotic, while that of the other case was a reaction to latex. Both patients showed elevated histamine and tryptase concentrations in blood samples. Recently, the incidence of allergic reactions to antibiotics and latex during anesthesia is increasing. Anesthesiologists should, therefore, be aware of the possibility of allergic reactions to all drugs and substances, especially to latex, during the perioperative period.

  14. Cascade enzymatic reactions for efficient carbon sequestration.

    Science.gov (United States)

    Xia, Shunxiang; Zhao, Xueyan; Frigo-Vaz, Benjamin; Zheng, Wenyun; Kim, Jungbae; Wang, Ping

    2015-04-01

    Thermochemical processes developed for carbon capture and storage (CCS) offer high carbon capture capacities, but are generally hampered by low energy efficiency. Reversible cascade enzyme reactions are examined in this work for energy-efficient carbon sequestration. By integrating the reactions of two key enzymes of RTCA cycle, isocitrate dehydrogenase and aconitase, we demonstrate that intensified carbon capture can be realized through such cascade enzymatic reactions. Experiments show that enhanced thermodynamic driving force for carbon conversion can be attained via pH control under ambient conditions, and that the cascade reactions have the potential to capture 0.5 mol carbon at pH 6 for each mole of substrate applied. Overall it manifests that the carbon capture capacity of biocatalytic reactions, in addition to be energy efficient, can also be ultimately intensified to approach those realized with chemical absorbents such as MEA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Nuclear Reaction Data File for Astrophysics (NRDF/A) in Hokkaido University Nuclear Reaction Data Center

    International Nuclear Information System (INIS)

    Kato, Kiyoshi; Kimura, Masaaki; Furutachi, Naoya; Makinaga, Ayano; Togashi, Tomoaki; Otuka, Naohiko

    2010-01-01

    The activities of the Japan Nuclear Reaction Data Centre is explained. The main task of the centre is data compilation of Japanese nuclear reaction data in collaboration of the International Network of Nuclear Reaction Data Centres. As one of recent activities, preparation of a new database (NRDF/A) and evaluation of astronuclear reaction data are reported. Collaboration in the nuclear data activities among Asian countries is proposed.

  16. Comparison of DSMC Reaction Models with QCT Reaction Rates for Nitrogen

    Science.gov (United States)

    2016-07-17

    include area code) N/A Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std. 239.18 Comparison of DSMC Reaction Models with QCT Reaction Rates ...controls vibration coupling A is adjusted to match thermal reaction rate Simplest to implement, not tied to any other model Distribution A: Approved for...General trend: reaction rate increases with v • TCE, QK: lack of vibrational favoring results in much lower slope as compared to the benchmark QCT • VFD: φ

  17. The dynamics of the Hg + Br2 reaction: elucidation of the reaction mechanism for the Br exchange reaction.

    Science.gov (United States)

    Jambrina, P G; Menéndez, M; Aoiz, F J

    2017-06-28

    In spite of its importance in the Hg atmospheric chemistry, the dynamics of the Hg + Br 2 → HgBr + Br reaction is poorly understood. In this article, we have carried out a comprehensive study of the reaction mechanism of this reaction by means of quasiclassical trajectories (QCTs) on an existing ab initio potential energy surface (PES). The reaction has a non trivial dynamics, as a consequence of its large endothermicity, the presence of a deep potential well, and the competition between the Br exchange and the collision induced dissociation processes. Our calculations demonstrate that insertion is only relevant at energies just above the reaction threshold and that, at energies above 2.3 eV, HgBr formation typically takes place via a sort of frustrated dissociation. In order to compare directly with the results obtained in extensive cross molecular beam experiments for the homologous reaction with I 2 , angular distributions in the laboratory frame for Hg + Br 2 have been simulated under similar experimental conditions. The lack of agreement at the highest energies considered suggests that either the two reactions have substantially different mechanisms or that calculations on a single PES cannot account for the dynamics at those energies.

  18. Connecting localized DNA strand displacement reactions

    Science.gov (United States)

    Mullor Ruiz, Ismael; Arbona, Jean-Michel; Lad, Amitkumar; Mendoza, Oscar; Aimé, Jean-Pierre; Elezgaray, Juan

    2015-07-01

    Logic circuits based on DNA strand displacement reactions have been shown to be versatile enough to compute the square root of four-bit numbers. The implementation of these circuits as a set of bulk reactions faces difficulties which include leaky reactions and intrinsically slow, diffusion-limited reaction rates. In this paper, we consider simple examples of these circuits when they are attached to platforms (DNA origamis). As expected, constraining distances between DNA strands leads to faster reaction rates. However, it also induces side-effects that are not detectable in the solution-phase version of this circuitry. Appropriate design of the system, including protection and asymmetry between input and fuel strands, leads to a reproducible behaviour, at least one order of magnitude faster than the one observed under bulk conditions.Logic circuits based on DNA strand displacement reactions have been shown to be versatile enough to compute the square root of four-bit numbers. The implementation of these circuits as a set of bulk reactions faces difficulties which include leaky reactions and intrinsically slow, diffusion-limited reaction rates. In this paper, we consider simple examples of these circuits when they are attached to platforms (DNA origamis). As expected, constraining distances between DNA strands leads to faster reaction rates. However, it also induces side-effects that are not detectable in the solution-phase version of this circuitry. Appropriate design of the system, including protection and asymmetry between input and fuel strands, leads to a reproducible behaviour, at least one order of magnitude faster than the one observed under bulk conditions. Electronic supplementary information (ESI) available. See DOI: 10.1039/C5NR02434J

  19. Electrode reactions in slowly relaxing media

    Science.gov (United States)

    Matyushov, Dmitry V.; Newton, Marshall D.

    2017-11-01

    Standard models of reaction kinetics in condensed materials rely on the Boltzmann-Gibbs distribution for the population of reactants at the top of the free energy barrier separating them from the products. While energy dissipation and quantum effects at the barrier top can potentially affect the transmission coefficient entering the rate pre-exponential factor, much stronger dynamical effects on the reaction barrier are caused by the breakdown of ergodicity for populating the reaction barrier (violation of the Boltzmann-Gibbs statistics). When the spectrum of medium modes coupled to the reaction coordinate includes fluctuations slower than the reaction rate, such nuclear motions dynamically freeze on the reaction time scale and do not contribute to the activation barrier. Here we consider the consequences of this scenario for electrode reactions in slowly relaxing media. Changing the electrode overpotential speeds the electrode electron transfer up, potentially cutting through the spectrum of nuclear modes coupled to the reaction coordinate. The reorganization energy of electrochemical electron transfer becomes a function of the electrode overpotential, switching between the thermodynamic value at low rates to the nonergodic limit at higher rates. The sharpness of this transition depends on the relaxation spectrum of the medium. The reorganization energy experiences a sudden drop with increasing overpotential for a medium with a Debye relaxation but becomes a much shallower function of the overpotential for media with stretched exponential dynamics. The latter scenario characterizes the electron transfer in ionic liquids. The analysis of electrode reactions in room-temperature ionic liquids shows that the magnitude of the free energy of nuclear solvation is significantly below its thermodynamic limit. This result applies to reaction times faster than microseconds and is currently limited by the available dielectric relaxation data.

  20. The quantum normal form approach to reactive scattering : The cumulative reaction probability for collinear exchange reactions

    NARCIS (Netherlands)

    Goussev, Arseni; Schubert, Roman; Waalkens, Holger; Wiggins, Stephen

    2009-01-01

    The quantum normal form approach to quantum transition state theory is used to compute the cumulative reaction probability for collinear exchange reactions. It is shown that for heavy-atom systems such as the nitrogen-exchange reaction, the quantum normal form approach gives excellent results and

  1. Effect of Reaction Developing Training on Audio-Visual Feet Reaction Time in Wrestlers

    Science.gov (United States)

    Kaya, Mustafa

    2016-01-01

    Reaction time is one of the most determinative elements for a successful sports performance. The purpose of this study was to investigate the effect of 12-week feet reaction developing trainings upon feet reaction time of females at 11-13 age interval. Volunteer sportsmen between 11 and 13 age interval who were active in Tokat Provincial…

  2. Model Experiment of Thermal Runaway Reactions Using the Aluminum-Hydrochloric Acid Reaction

    Science.gov (United States)

    Kitabayashi, Suguru; Nakano, Masayoshi; Nishikawa, Kazuyuki; Koga, Nobuyoshi

    2016-01-01

    A laboratory exercise for the education of students about thermal runaway reactions based on the reaction between aluminum and hydrochloric acid as a model reaction is proposed. In the introductory part of the exercise, the induction period and subsequent thermal runaway behavior are evaluated via a simple observation of hydrogen gas evolution and…

  3. The oxygen evolution reaction on cobalt Part I. Reaction order experiments and impedance measurements

    NARCIS (Netherlands)

    Kobussen, A.G.C.; Willems, H.; Wit, J.H.W. de; Broers, G.H.J.

    1984-01-01

    It was found that the oxygen evolution reaction on cobalt in concentrated KOH solutions can be described differently for low and high overpotentials. In the overpotential range from 150 to 280 mV, the reaction has a Tafel slope of approximately 40 mV and a reaction order with respect to the KOH

  4. Synthesis and Reactions of Acenaphthenequinones-Part-2. The Reactions of Acenaphthenequinones

    Directory of Open Access Journals (Sweden)

    Mahmoud Shoukry

    2002-02-01

    Full Text Available The reactions of acenaphthenequinone and its derivatives with different nucleophiles, organic and inorganic reagents are reviewed. This survey also covers their oxidation and reduction reactions, in addition to many known reactions such as Friedel Crafts, Diels-Alder, bromination and thiolation.

  5. A Green Multicomponent Reaction for the Organic Chemistry Laboratory: The Aqueous Passerini Reaction

    Science.gov (United States)

    Hooper, Matthew M.; DeBoef, Brenton

    2009-01-01

    Water is the ideal green solvent for organic reactions. However, most organic molecules are insoluble in it. Herein, we report a laboratory module that takes advantage of this property. The Passerini reaction, a three-component coupling involving an isocyanide, aldehyde, and carboxylic acid, typically requires [similar to] 24 h reaction times in…

  6. High-precision (p,t) reactions to determine reaction rates of explosive stellar processes

    NARCIS (Netherlands)

    Matić, Andrija

    2007-01-01

    The aim of my study was to investigate the nuclear structure of 22Mg and 26Si. These two nuclei play a significant role in stellar reaction processes at high temperatures. On base of the obtained nuclear structure we calculated the stellar reaction rates for the following reactions: 18Ne(α,p)21Na,

  7. Trend to equilibrium for a reaction-diffusion system modelling reversible enzyme reaction

    OpenAIRE

    Elias, Jan

    2016-01-01

    20 pages; A spatio-temporal evolution of chemicals appearing in a reversible enzyme reaction and modelled by a four component reaction-diffusion system with the reaction terms obtained by the law of mass action is considered. The large time behaviour of the system is studied by means of entropy methods.

  8. Trend to Equilibrium for a Reaction-Diffusion System Modelling Reversible Enzyme Reaction.

    Science.gov (United States)

    Eliaš, Ján

    2018-01-01

    A spatio-temporal evolution of chemicals appearing in a reversible enzyme reaction and modelled by a four-component reaction-diffusion system with the reaction terms obtained by the law of mass action is considered. The large time behaviour of the system is studied by means of entropy methods.

  9. Severe catastrophes and public reactions

    International Nuclear Information System (INIS)

    Osmachkin, Vitaly

    2002-01-01

    nuclear opposition. Economical basis of nuclear energy stagnation is in not very successful competition of nuclear engineering with fossil energy production technologies. Much money has been spent for improvement of safety of NPPs. Social roots of the opposition are linked with a bad experience of the public with demonstration of the nuclear energy- The explosion of atomic bombs, some contamination of the territories after nuclear arm tests, misfortunes with TMI-2 and Chernobyl have created a stable enmity and non-acceptance of the all connected with 'atom'. The mass media have strongly promoted the dissemination of the fear of radiation exposures. There is also an influence on that attitude the radiation protection regulation via the declaration of the linear no-threshold dependence of the radiation detriments and dose of exposure. Such concept ignores the adoptive features of all living. But modem studies have showed that protracted irradiation at the same dose is much less dangerous compared with sharp one. It could change public attitude to nuclear energy in the society. Role of nuclear communication for public informing: The reactions of public on various technological and man-made events differ significantly and are being determined not scales of catastrophes but the mental impression and a multiplication of psychological stresses in the society by mass -media. In present situation a nuclear community has to improve the contacts with the pubic, to launch more effective campaign for explanation of real adventures of nuclear power. It needs to compare the risks of climate warming and health detriments from different electricity production technologies and to show that nuclear power is a single alternative all fossil burning techniques of electricity production. It's the truth the nuclear power is a real method of fight for suppression of emission the greenhouse gases, isn't it? (author)

  10. Department of Nuclear Reactions - Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2008-01-01

    . Jaskola joined a collaboration of many Polish institutions and performed a series of experiments at the Heavy Ion Laboratory of Warsaw University devoted to a study of cell survival after irradiation by ions from the Warsaw Cyclotron. Finally, I would like to warmly welcome drs H.P. Morsch and N. Keeley who joined us last year. Dr Morsch is collaborating with Assoc. Prof. P. Zupranski on a multi-gluon field approach within Quantum Chromodynamics. Dr Keeley's interest is in low energy nuclear reactions. I would also like to welcome our new PhD students, Ms I. Strojek, Mr l. Standylo and Mr Shaaban Abd El Aal. With Mr Abd El Aal we are opening a new field of applications of nuclear methods, studying ancient Egyptian frescos by means of proton induced X-ray emission (PIXE). As every year, apart from purely scientific activities, a few of our colleagues have been involved in education, giving lectures to students from highs Schools in Warsaw and to students of Warsaw University. (author)

  11. Department of Nuclear Reactions: Overview

    International Nuclear Information System (INIS)

    Rusek, K.

    2005-01-01

    Full text: It is surprising how so few under-paid scientists could do so much. During 2004 the number of papers published or being in press exceeded fifty, making almost three papers per person employed in our department. Furthermore, among these papers one was published in Nature, the World's highest-ranked scientific journal. This is a result that will be difficult to beat. It is my pleasure to mention that one of our PhD students, Mr Sergiy Mezhevych, won a prestigious Heavy Ion Laboratory Prize founded by Prof. Inamura, for his experimental work using a beam from the Warsaw Cyclotron. Thanks to the effort of our colleagues the Hermes Collaboration Meeting organized by IPJ in Kazimierz Dolny (June 25 - July 1) turned out a success. The following short reports cover the three major domains of our scientific activities: nuclear, materials and atomic physics. -Nuclear physics - The structure of light nuclei, including exotic radioactive isotopes, was investigated both experimentally and theoretically. Some experimental studies were performed at the Heavy Ion Laboratory of Warsaw University in collaboration with scientists from the Institute of Nuclear Research in Kiev, Ukraine. The two reports present interesting results for the rare carbon isotope, 14 C. In the framework of Feshbach, Kerman and Koonin theory the multistep emission of one particle as well as more complicated direct processes were studied. It was found that these more complex processes play an important role in proton induced reactions. Experimental data from projectile-multifragmentation experiments with stable and radioactive beams were analysed. Some preliminary results are presented. Using a proton beam provided by the C-30 compact cyclotron at Swierk, detectors consisting of a PWO scintillator coupled to avalanche photodiodes were tested. The aim of these tests was to find the best detectors for the large electromagnetic calorimeter which will be used in future PANDA Collaboration experiments

  12. Resonant elastic scattering, inelastic scattering and astrophysical reactions; Diffusion elastique resonante, diffusion inelastique et reactions astrophysiques

    Energy Technology Data Exchange (ETDEWEB)

    De Oliveira Santos, F. [Grand Accelerateur National d' Ions Lourds, UMR 6415, 14 - Caen (France)

    2007-07-01

    Nuclear reactions can occur at low kinetic energy. Low-energy reactions are characterized by a strong dependence on the structure of the compound nucleus. It turns out that it is possible to study the nuclear structure by measuring these reactions. In this course, three types of reactions are treated: Resonant Elastic Scattering (such as N{sup 14}(p,p)N{sup 14}), Inelastic Scattering (such as N{sup 14}(p,p')N{sup 14*}) and Astrophysical reactions (such as N{sup 14}(p,{gamma})O{sup 15}). (author)

  13. Kiss-induced severe anaphylactic reactions

    Directory of Open Access Journals (Sweden)

    Atanasković-Marković Marina

    2010-01-01

    Full Text Available Introduction. Ingestion is the principal route for food allergens to trigger allergic reaction in atopic persons. However, in some highly sensitive patients severe symptoms may develop upon skin contact and by inhalation. The clinical spectrum ranges from mild facial urticaria and angioedema to life-threatening anaphylactic reactions. Outline of Cases. We describe cases of severe anaphylactic reactions by skin contact, induced by kissing in five children with prior history of severe anaphylaxis caused by food ingestion. These cases were found to have the medical history of IgE mediated food allergy, a very high total and specific serum IgE level and very strong family history of allergy. Conclusion. The presence of tiny particles of food on the kisser's lips was sufficient to trigger an anaphylactic reaction in sensitized children with prior history of severe allergic reaction caused by ingestion of food. Allergic reaction provoked with food allergens by skin contact can be a risk factor for generalized reactions. Therefore, extreme care has to be taken in avoiding kissing allergic children after eating foods to which they are highly allergic. Considering that kissing can be a cause of severe danger for the food allergic patient, such persons should inform their partners about the risk factor for causing their food hypersensitivity.

  14. Spontaneous Hedonic Reactions to Social Media Cues.

    Science.gov (United States)

    van Koningsbruggen, Guido M; Hartmann, Tilo; Eden, Allison; Veling, Harm

    2017-05-01

    Why is it so difficult to resist the desire to use social media? One possibility is that frequent social media users possess strong and spontaneous hedonic reactions to social media cues, which, in turn, makes it difficult to resist social media temptations. In two studies (total N = 200), we investigated less-frequent and frequent social media users' spontaneous hedonic reactions to social media cues using the Affect Misattribution Procedure-an implicit measure of affective reactions. Results demonstrated that frequent social media users showed more favorable affective reactions in response to social media (vs. control) cues, whereas less-frequent social media users' affective reactions did not differ between social media and control cues (Studies 1 and 2). Moreover, the spontaneous hedonic reactions to social media (vs. control) cues were related to self-reported cravings to use social media and partially accounted for the link between social media use and social media cravings (Study 2). These findings suggest that frequent social media users' spontaneous hedonic reactions in response to social media cues might contribute to their difficulties in resisting desires to use social media.

  15. Prevention of allergic reactions in anesthetized patients.

    Science.gov (United States)

    Caffarelli, C; Stringari, G; Miraglia Del Giudice, M; Crisafulli, G; Cardinale, F; Peroni, D G; Bernardini, R

    2011-01-01

    Hypersensitivity reactions during perioperative period are increasing and may be potentially life-threatening. Therefore, major emphasis is given to prevention. We perform a review to examine which measures should be taken to prevent reactions to products used in elective and emergency surgery. Any patient with a history of previous anaphylaxis or severe reaction during anaesthesia should be referred to allergist for detection of the offending compound. However, the identification of the triggering agent is not always feasible because of the low accuracy of diagnostic tests. In these cases and when emergency surgery is required, it should be considered to replace all drugs administered before the onset of the reaction with alternatives. Furthermore, any cross-reacting agent and latex, especially in patients belonging to populations at-risk for latex allergy should be avoided. In susceptible patients, premedication with antihistamines and corticosteroids might reduce the severity of reaction to drugs or contrast material while it is unclear whether pre-treatment decreases incidence of anaphylactic reactions. There is no evidence that premedication prevents allergic reactions to latex. Overall, physicians should not rely on the efficacy of premedication.

  16. Photogeochemical reactions of manganese under anoxic conditions

    Science.gov (United States)

    Liu, W.; Yee, N.; Piotrowiak, P.; Falkowski, P. G.

    2017-12-01

    Photogeochemistry describes reactions involving light and naturally occurring chemical species. These reactions often involve a photo-induced electron transfer that does not occur in the absence of light. Although photogeochemical reactions have been known for decades, they are often ignored in geochemical models. In particular, reactions caused by UV radiation during an ozone free early Earth could have influenced the available oxidation states of manganese. Manganese is one of the most abundant transition metals in the crust and is important in both biology and geology. For example, the presence of manganese (VI) oxides in the geologic record has been used as a proxy for oxygenic photosynthesis; however, we suggest that the high oxidation state of Mn can be produced abiotically by photochemical reactions. Aqueous solutions of manganese (II) as well as suspensions of rhodochrosite (MnCO3) were irradiated under anoxic condition using a 450 W mercury lamp and custom built quartz reaction vessels. The photoreaction of the homogeneous solution of Mn(II) produced H2 gas and akhtenskite (ɛ-MnO2) as the solid product . This product is different than the previously identified birnessite. The irradiation of rhodochrosite suspensions also produced H2 gas and resulted in both a spectral shift as well as morphology changes of the mineral particles in the SEM images. These reactions offer alternative, abiotic pathways for the formation of manganese oxides.

  17. ReactionMap: an efficient atom-mapping algorithm for chemical reactions.

    Science.gov (United States)

    Fooshee, David; Andronico, Alessio; Baldi, Pierre

    2013-11-25

    Large databases of chemical reactions provide new data-mining opportunities and challenges. Key challenges result from the imperfect quality of the data and the fact that many of these reactions are not properly balanced or atom-mapped. Here, we describe ReactionMap, an efficient atom-mapping algorithm. Our approach uses a combination of maximum common chemical subgraph search and minimization of an assignment cost function derived empirically from training data. We use a set of over 259,000 balanced atom-mapped reactions from the SPRESI commercial database to train the system, and we validate it on random sets of 1000 and 17,996 reactions sampled from this pool. These large test sets represent a broad range of chemical reaction types, and ReactionMap correctly maps about 99% of the atoms and about 96% of the reactions, with a mean time per mapping of 2 s. Most correctly mapped reactions are mapped with high confidence. Mapping accuracy compares favorably with ChemAxon's AutoMapper, versions 5 and 6.1, and the DREAM Web tool. These approaches correctly map 60.7%, 86.5%, and 90.3% of the reactions, respectively, on the same data set. A ReactionMap server is available on the ChemDB Web portal at http://cdb.ics.uci.edu .

  18. Local and general anesthetics immediate hypersensitivity reactions.

    Science.gov (United States)

    Volcheck, Gerald W; Mertes, Paul Michel

    2014-08-01

    Intraoperative anaphylaxis and hypersensitivity reactions in the setting of anesthesia contribute significantly to the morbidity and mortality of surgeries and surgical procedures. Because multiple medications and products are given in a short period of time, identifying the specific cause can be difficult. Neuromuscular blocking agents, antibiotics, and latex are the most common causes of anesthesia-related reactions, though other medications or exposures could be involved. Careful review of anesthetic charts and allergy testing can help identify the underlying cause. The identification of the cause and subsequent prevention of reactions are critical to reduce overall mortality and morbidity related to anesthesia. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Polar reactions of acyclic conjugated bisallenes

    Directory of Open Access Journals (Sweden)

    Reiner Stamm

    2013-01-01

    Full Text Available The chemical behaviour of various alkyl-substituted, acyclic conjugated bisallenes in reactions involving polar intermediates and/or transition states has been investigated on a broad scale for the first time. The reactions studied include lithiation, reaction of the thus formed organolithium salts with various electrophiles (among others, allyl bromide, DMF and acetone, oxidation to cyclopentenones and epoxides, hydrohalogenation (HCl, HBr addition, halogenation (Br2 and I2 addition, and [2 + 2] cycloaddition with chlorosulfonyl isocyanate. The resulting adducts were fully characterized by spectroscopic and analytical methods; they constitute interesting substrates for further organic transformations.

  20. Rates of Thermonuclear Reactions in Dense Plasmas

    International Nuclear Information System (INIS)

    Tsytovich, V.N.; Bornatici, M.

    2000-01-01

    The problem of plasma screening of thermonuclear reactions has attracted considerable scientific interest ever since Salpeter's seminal paper, but it is still faced with controversial statements and without any definite conclusion. It is of relevant importance to thermonuclear reactions in dense astrophysical plasmas, for which charge screening can substantially affect the reaction rates. Whereas Salpeter and a number of subsequent investigations have dealt with static screening, Carraro, Schafer, and Koonin have drawn attention to the fact that plasma screening of thermonuclear reactions is an essentially dynamic effect. In addressing the issue of collective plasma effects on the thermonuclear reaction rates, the first critical overview of most of the work carried out so far is presented and the validity of the test particle approach is assessed. In contrast to previous investigations, we base our description on the kinetic equation for nonequilibrium plasmas, which accounts for the effects on the rates of thermonuclear reactions of both plasma fluctuations and screening and allows one to analyze explicitly the effects of the fluctuations on the reaction rates. Such a kinetic formulation is more general than both Salpeter's approach and the recently developed statistical approaches and makes it possible to obtain a more comprehensive understanding of the problem. A noticeable result of the fluctuation approach is that the static screening, which affects both the interaction and the self-energy of the reacting nuclei, does not affect the reaction rates, in contrast with the results obtained so far. Instead, a reduction of the thermonuclear reaction rates is obtained as a result of the effect of plasma fluctuations related to the free self-energy of the reacting nuclei. A simple physical explanation of the slowing down of the reaction rates is given, and the relation to the dynamically screened test particle approach is discussed. Corrections to the reaction rates

  1. Flows and chemical reactions in heterogeneous mixtures

    CERN Document Server

    Prud'homme, Roger

    2014-01-01

    This book - a sequel of previous publications 'Flows and Chemical Reactions' and 'Chemical Reactions in Flows and Homogeneous Mixtures' - is devoted to flows with chemical reactions in heterogeneous environments.  Heterogeneous media in this volume include interfaces and lines. They may be the site of radiation. Each type of flow is the subject of a chapter in this volume. We consider first, in Chapter 1, the question of the generation of environments biphasic individuals: dusty gas, mist, bubble flow.  Chapter 2 is devoted to the study at the mesoscopic scale: particle-fluid exchange of mom

  2. Lithium induced nuclear reactions of astrophysical interest

    Energy Technology Data Exchange (ETDEWEB)

    Liu, W.P. [CIAE, China Institute of Atomic Energy, P. O. Box 275(1), Beijing 102413 (China); Li, Z.H.; Bai, X.X.; Wang, Y.B.; Lian, G.; Guo, B.; Su, J.; Zeng, S.; Wang, B.X.; Yan, S.Q.; Li, Y.J.; Li, E.T. [CIAE, China Institute of Atomic Energy, P. O. Box 275(46), Beijing 102413 (China)

    2010-03-01

    Systematic studies of nuclear astrophysical reactions induced by lithium isotopes using the unstable ion beam facility GIRAFFE in CIAE were performed. We have measured the angular distributions of some single nucleon transfer reactions, such as {sup 8}Li(d,p){sup 9}Li, {sup 8}Li(d,n){sup 9}Be and {sup 8}Li(p,d){sup 7}Li in inverse kinematics, and derived the astrophysical S-factors or reaction rates for {sup 8}Li(n,gamma){sup 9}Li and {sup 8}Li(p,gamma){sup 9}Be by using asymptotic normalization coefficient (ANC) or spectroscopic factor.

  3. Nuclear reaction inputs based on effective interactions

    Energy Technology Data Exchange (ETDEWEB)

    Hilaire, S.; Peru, S.; Dubray, N.; Dupuis, M.; Bauge, E. [CEA, DAM, DIF, Arpajon (France); Goriely, S. [Universite Libre de Bruxelles, Institut d' Astronomie et d' Astrophysique, CP-226, Brussels (Belgium)

    2016-11-15

    Extensive nuclear structure studies have been performed for decades using effective interactions as sole input. They have shown a remarkable ability to describe rather accurately many types of nuclear properties. In the early 2000 s, a major effort has been engaged to produce nuclear reaction input data out of the Gogny interaction, in order to challenge its quality also with respect to nuclear reaction observables. The status of this project, well advanced today thanks to the use of modern computers as well as modern nuclear reaction codes, is reviewed and future developments are discussed. (orig.)

  4. Supercritical Fluid Reactions for Coal Processing

    Energy Technology Data Exchange (ETDEWEB)

    Charles A. Eckert

    1997-11-01

    Exciting opportunities exist for the application of supercritical fluid (SCF) reactions for the pre-treatment of coal. Utilizing reactants which resemble the organic nitrogen containing components of coal, we developed a method to tailor chemical reactions in supercritical fluid solvents for the specific application of coal denitrogenation. The tautomeric equilibrium of a Schiff base was chosen as one model system and was investigated in supercritical ethane and cosolvent modified supercritical ethane. The Diels-Alder reaction of anthracene and 4-phenyl-1,2,4-triazoline-3,5-dione (PTAD) was selected as a second model system, and it was investigated in supercritical carbon dioxide.

  5. Morphing of the Dissipative Reaction Mechanism

    International Nuclear Information System (INIS)

    Schroeder, W.U.; Toke, J.; Gawlikowicz, W.; Houck, M.A.; Lu, J.; Pienkowski, L.

    2003-01-01

    Important trends in the evolution of heavy-ion reaction mechanisms with bombarding energy and impact parameter are reviewed. Essential features of dissipative reactions appear preserved at E/A = 50-62 MeV, such as dissipative orbiting and multi-nucleon exchange. The relaxation of the A/Z asymmetry with impact parameter is slow. Non-equilibrium emission of light particles and clusters is an important process accompanying the evolution of the mechanism. Evidence is presented for a new mechanism of statistical cluster emission from hot, metastable primary reaction products, driven by surface entropy. These results suggest a plausible reinterpretation of multi-fragmentation. (authors)

  6. Conservation Laws in Biochemical Reaction Networks

    DEFF Research Database (Denmark)

    Mahdi, Adam; Ferragut, Antoni; Valls, Claudia

    2017-01-01

    We study the existence of linear and nonlinear conservation laws in biochemical reaction networks with mass-action kinetics. It is straightforward to compute the linear conservation laws as they are related to the left null-space of the stoichiometry matrix. The nonlinear conservation laws...... are difficult to identify and have rarely been considered in the context of mass-action reaction networks. Here, using the Darboux theory of integrability, we provide necessary structural (i.e., parameterindependent) conditions on a reaction network to guarantee the existence of nonlinear conservation laws...

  7. Reactions of nitrogen oxides with polymers

    Energy Technology Data Exchange (ETDEWEB)

    Pariiskii, Georgii B; Gaponova, I S; Davydov, Evgenii Ya [N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow (Russian Federation)

    2000-11-30

    The mechanisms of the reactions of nitrogen oxides and different classes of solid polymers are considered. Particular emphasis is given to the analysis of the mechanisms of the formation of stable nitroxyl radicals. Double bonds and amide groups of macromolecules, as well as hydroperoxides and peroxide macroradicals are shown to be involved in the reactions with nitrogen oxides. The application of nitrogen oxides for the preparation of spin-labelled polymers and the use of the ESR imaging technique (ESR tomography) for the investigation of the structure of the reaction front during nitration of solid polymers are considered. The bibliography includes 111 references.

  8. Nuclear chain reaction: forty years later

    International Nuclear Information System (INIS)

    Sachs, R.G.

    1984-01-01

    The proceedings from a 1982 symposium 40 years after the first controlled nuclear chain reaction took place in Chicago covers four sessions and public discussion. The session covered the history of the chain reaction; peaceful uses in technology, medicine, and biological science; peaceful uses in power generation; and nuclear weapons control. Among the speakers were Eugene Wigner, Glenn Seaborg, Alvin Weinberg, and others who participated in the first chain reaction experiments. The proceedings reflect differences of opinion among the scientists as well as the general public. References, slides, and tables used to illustrate the individual talks are included with the papers

  9. Radiative capture reactions via indirect methods

    Science.gov (United States)

    Mukhamedzhanov, A. M.; Rogachev, G. V.

    2017-10-01

    Many radiative capture reactions of astrophysical interest occur at such low energies that their direct measurement is hardly possible. Until now the only indirect method, which was used to determine the astrophysical factor of the astrophysical radiative capture process, was the Coulomb dissociation. In this paper we address another indirect method, which can provide information about resonant radiative capture reactions at astrophysically relevant energies. This method can be considered an extension of the Trojan horse method for resonant radiative capture reactions. The idea of the suggested indirect method is to use the indirect reaction A (a ,s γ )F to obtain information about the radiative capture reaction A (x ,γ )F , where a =(s x ) and F =(x A ) . The main advantage of using the indirect reactions is the absence of the penetrability factor in the channel x +A , which suppresses the low-energy cross sections of the A (x ,γ )F reactions and does not allow one to measure these reactions at astrophysical energies. A general formalism to treat indirect resonant radiative capture reactions is developed when only a few intermediate states contribute and a statistical approach cannot be applied. The indirect method requires coincidence measurements of the triple differential cross section, which is a function of the photon scattering angle, energy, and the scattering angle of the outgoing spectator particle s . Angular dependence of the triple differential cross section at fixed scattering angle of the spectator s is the angular γ -s correlation function. Using indirect resonant radiative capture reactions, one can obtain information about important astrophysical resonant radiative capture reactions such as (p ,γ ) , (α ,γ ) , and (n ,γ ) on stable and unstable isotopes. The indirect technique makes accessible low-lying resonances, which are close to the threshold, and even subthreshold bound states located at negative energies. In this paper, after

  10. Tryptase in diagnosing adverse suspected anaphylactic reaction.

    Science.gov (United States)

    Michalska-Krzanowska, Grazyna

    2012-01-01

    Determination of serum mast cell tryptase (MCT) is becoming more widely used in diagnosing allergic reactions involving mast cells. It can help evaluate the allergenic effects of drugs administered during anesthesia and the perioperative period. Until now, data about the role of tryptase in the body has not been clarified yet. Patients with elevated MCT levels should undergo further testing to find out the causative agent of a potential allergic reaction. Patients with normal tryptase concentration should also undergo further diagnosis if they manifest clinical symptoms of a severe anaphylactic reaction.

  11. Photochemical Hexadehydro-Diels-Alder Reaction.

    Science.gov (United States)

    Xu, Feng; Xiao, Xiao; Hoye, Thomas R

    2017-06-28

    We demonstrate that the hexadehydro-Diels-Alder (HDDA) cycloisomerization reaction to produce reactive benzyne derivatives can be initiated photochemically. As with the thermal variant of the HDDA process, the reactive intermediates are formed in the absence of reagents or the resulting byproducts required for the generation of benzynes by traditional methods. This photo-HDDA (or hν-HDDA) reaction occurs at much lower temperatures (including even at -70 °C) than the thermal HDDA, but the benzynes produced behave in the same fashion with respect to their trapping reactions, suggesting they are of the same electronic state.

  12. Thermonuclear reaction rates for proton induced reactions on 41K and neutron induced reactions on 41Ca

    International Nuclear Information System (INIS)

    Sevior, M.E.; Anderson, M.R.; Mitchell, L.W.; Kennett, S.R.; Sargood, D.G.

    1981-01-01

    The yield of γ-rays from the reaction 41 K(p,γ) 42 Ca has been measured as a function of bombarding energy over the range 0.68-2.48 MeV and from the reaction 41 K(p,αγ) 38 Ar over the range 1.20-2.48 MeV, and the yield of neutrons from the reaction 41 K(p,n) 41 Ca has been measured from threshold to a bombarding energy of 2.48 MeV. The energy dependence of the cross sections is compared with statistical-model calculations with global optical model parameters in all particle channels. The calculations seriously overestimate the cross section for the neutron channel and underestimate those for the other channels. A reduction in the imaginary well depth in the neutron channel leads to good agreement with all the data. Statistical-model calculations with this modified set of parameters are then carried out to provide cross sections for the astrophysically interesting reactions 41 Ca(n,p) 41 K, 41 Ca(n,α) 38 Ar, and 41 Ca(n,γ) 42 Ca. Thermonuclear reaction rates are calculated for all six reactions over the temperature range 5 x 10 8 - 10 1 0K which includes the range of temperatures of interest in nucleosynthesis calculations

  13. Kinetics interpretation model of isothermal martensite reactions

    International Nuclear Information System (INIS)

    Guimaraes, J.R.C.

    1976-01-01

    It was discussed details associated to the interpretation of kinetics of martencite heterogeneous nucleation in isothermal reactions. It was proposed a model which allows compute the variation of concentration of preferencial sites nucleation with a volumetric martencite fraction [pt

  14. Injection site reactions after subcutaneous oligonucleotide therapy

    NARCIS (Netherlands)

    van Meer, L. (Leonie); M. Moerland (Matthijs); Gallagher, J. (Jolie); M.B.A. van Doorn (Martijn); E.P. Prens (Errol); A.F. Cohen; Rissmann, R. (Robert); J. Burggraaf (Jacobus)

    2016-01-01

    textabstractOligonucleotides (ONs) are short fragments of nucleic acids, currently being investigated as therapeutic agents. When administered subcutaneously (sc), ONs cause a specific local reaction originating around the injection site, such as erythema, itching, discomfort and pain, including

  15. Polymerase chain reaction identification of Trypanosoma brucei ...

    African Journals Online (AJOL)

    Polymerase chain reaction identification of Trypanosoma brucei rhodesiense in wild tsetse flies from Nkhotakota Wildlife Reserve, Malawi. Janelisa Musaya, John Chisi, Edward Senga, Peter Nambala, Emmanuel Maganga, Enock Matovu, John Enyaru ...

  16. Chemical Reactions at Surfaces. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    Freud, Hans-Joachim [Max-Planck-Gesellschaft, Berlin (Germany). Fritz-Haber-Inst.

    2003-02-21

    The Gordon Research Conference (GRC) on Chemical Reactions at Surfaces was held at Holiday Inn, Ventura, California, 2/16-21/03. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  17. Adverse drug reactions: classification, susceptibility and reporting.

    Science.gov (United States)

    Kaufman, Gerri

    2016-08-10

    Adverse drug reactions (ADRs) are increasingly common and are a significant cause of morbidity and mortality. Historically, ADRs have been classified as type A or type B. Type A reactions are predictable from the known pharmacology of a drug and are associated with high morbidity and low mortality. Type B reactions are idiosyncratic, bizarre or novel responses that cannot be predicted from the known pharmacology of a drug and are associated with low morbidity and high mortality. Not all ADRs fit into type A and type B categories; therefore, additional categories have been developed. These include type C (continuing), type D (delayed use), and type E (end of use) reactions. Susceptibility to ADRs is influenced by age, gender, disease states, pregnancy, ethnicity and polypharmacy. Drug safety is reliant on nurses and other healthcare professionals being alert to the possibility of ADRs, working with patients to optimise medicine use and exercising vigilance in the reporting of ADRs through the Yellow Card Scheme.

  18. Multistage reaction pathways in detonating high explosives

    International Nuclear Information System (INIS)

    Li, Ying; Kalia, Rajiv K.; Nakano, Aiichiro; Nomura, Ken-ichi; Vashishta, Priya

    2014-01-01

    Atomistic mechanisms underlying the reaction time and intermediate reaction products of detonating high explosives far from equilibrium have been elusive. This is because detonation is one of the hardest multiscale physics problems, in which diverse length and time scales play important roles. Here, large spatiotemporal-scale reactive molecular dynamics simulations validated by quantum molecular dynamics simulations reveal a two-stage reaction mechanism during the detonation of cyclotrimethylenetrinitramine crystal. Rapid production of N 2 and H 2 O within ∼10 ps is followed by delayed production of CO molecules beyond ns. We found that further decomposition towards the final products is inhibited by the formation of large metastable carbon- and oxygen-rich clusters with fractal geometry. In addition, we found distinct unimolecular and intermolecular reaction pathways, respectively, for the rapid N 2 and H 2 O productions

  19. An Elegant Example of Chemoselective Reaction

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 10. An Elegant Example of a Chemoselective Reaction - The Preparation of Sulfonamide Drugs. Gopalpur Nagendrappa. General Article Volume 13 Issue 10 October ... Keywords. Chemoselectivity; sulfa drugs; sulfonamides; amide hydrolysis.

  20. Study of solid metal/ceramic reactions

    International Nuclear Information System (INIS)

    Mehan, R.L.; Jackson, M.R.

    1981-01-01

    In advanced energy systems, ceramics may allow higher operating temperatures for greater efficiency. However, compressive contacts at joints with metals are required by the poor tensile behavior of ceramics. Compression at these interfaces excludes oxygen, and oxides do not form. Reactions under inert or reducing conditions (as in metal matrix composites) have been studied, as have reactions of complex superalloys with SiC, Si/SiC and Si 3 N 4 . The reactions were complex, dictating a phenomenological study with no treatment of their basic nature or the phase equilibria. With a model alloy containing only Ni, Cr and Al, the present experiments and analyses are an attempt to gain a more basic understanding of metal/ceramic reactions

  1. Hadron--hadron reactions, high multiplicity

    International Nuclear Information System (INIS)

    Diebold, R.

    1978-09-01

    A coverage of results on high energy and high multiplicity hadron reactions, charm searches and related topics, ultrahigh energy events and exotic phenomena (cosmic rays), and the nuclear effects in high energy collisions and related topics is discussed. 67 references

  2. Method for predicting enzyme-catalyzed reactions

    Science.gov (United States)

    Hlavacek, William S.; Unkefer, Clifford J.; Mu, Fangping; Unkefer, Pat J.

    2013-03-19

    The reactivity of given metabolites is assessed using selected empirical atomic properties in the potential reaction center. Metabolic reactions are represented as biotransformation rules. These rules are generalized from the patterns in reactions. These patterns are not unique to reactants but are widely distributed among metabolites. Using a metabolite database, potential substructures are identified in the metabolites for a given biotransformation. These substructures are divided into reactants or non-reactants, depending on whether they participate in the biotransformation or not. Each potential substructure is then modeled using descriptors of the topological and electronic properties of atoms in the potential reaction center; molecular properties can also be used. A Support Vector Machine (SVM) or classifier is trained to classify a potential reactant as a true or false reactant using these properties.

  3. The serology of febrile transfusion reactions

    NARCIS (Netherlands)

    de Rie, M. A.; van der Plas-van Dalen, C. M.; Engelfriet, C. P.; von dem Borne, A. E.

    1985-01-01

    Sera from 40 patients with febrile, nonhemolytic transfusion reactions were tested for the presence of alloantibodies using a number of techniques, including immuno-fluorescence tests on granulocytes, lymphocytes and platelets, a modified NIH lymphocytotoxicity test and the leukocyte agglutination

  4. Dynamical dipole mode in fusion reactions

    Science.gov (United States)

    Pierroutsakou, D.; Martin, B.; Agodi, C.; Alba, R.; Baran, V.; Boiano, A.; Cardella, G.; Colonna, M.; Coniglione, R.; De Filippo, E.; Del Zoppo, A.; Di Toro, M.; Inglima, G.; Glodariu, T.; La Commara, M.; Maiolino, C.; Mazzocco, M.; Pagano, A.; Piattelli, P.; Pirrone, S.; Rizzo, C.; Romoli, M.; Sandoli, M.; Santonocito, D.; Sapienza, P.; Signorini, C.

    2009-05-01

    We investigated the dynamical dipole mode, related with entrance channel charge asymmetry effects, in the 40Ar+92Zr and 36Ar+96Zr fusion reactions at Elab = 15.1 A and 16 A MeV, respectively. These reactions populate, through entrance channels having different charge asymmetries, a compound nucleus in the A = 126 mass energy region, identical spin distribution at an average excitation energy of about 280 MeV. The compound nucleus average excitation energy and average mass were deduced by the analysis of the light charged particle energy spectra. By studying the γ-ray energy spectra and the γ-ray angular distributions of the considered reactions, the dynamical nature of the prompt radiation related to the dynamical dipole mode was evidenced. The data are compared with calculations based on a collective bremsstrahlung analysis of the reaction dynamics.

  5. Dynamical dipole mode in fusion reactions

    International Nuclear Information System (INIS)

    Pierroutsakou, D.; Boiano, A.; Romoli, M.; Martin, B.; Inglima, G.; La Commara, M.; Sandoli, M.; Agodi, C.; Alba, R.; Coniglione, R.; Zoppo, A. Del; Maiolino, C.; Piattelli, P.; Santonocito, D.; Sapienza, P.; Baran, V.; Glodariu, T.; Cardella, G.; De Filippo, E.; Pagano, A.

    2009-01-01

    We investigated the dynamical dipole mode, related with entrance channel charge asymmetry effects, in the 40 Ar+ 92 Zr and 36 Ar+ 96 Zr fusion reactions at E lab = 15.1 A and 16 A MeV, respectively. These reactions populate, through entrance channels having different charge asymmetries, a compound nucleus in the A = 126 mass energy region, identical spin distribution at an average excitation energy of about 280 MeV. The compound nucleus average excitation energy and average mass were deduced by the analysis of the light charged particle energy spectra. By studying the γ-ray energy spectra and the γ-ray angular distributions of the considered reactions, the dynamical nature of the prompt radiation related to the dynamical dipole mode was evidenced. The data are compared with calculations based on a collective bremsstrahlung analysis of the reaction dynamics.

  6. The investigation on CNO burning reaction rate

    International Nuclear Information System (INIS)

    He Jianhua; Yang Jinqing; Peng Qiuhe

    1992-01-01

    The Barrier Penetration Model has been used to calculate the heavy ion fusion cross section and it does give a good description of the experimental data in existence. Based on this, the reaction rates of CNO fusion at various temperature have been calculated and the approximated analytic expressions of the reaction rates versus temperature have also been given. For the reaction rates of 12 C + 12 C and 16 O + 16 O, our results are evidently smaller than the results given by Caughlan et al. in 1985. Especially for the reaction 16 O + 16 O, its new rate is only a small fraction (1/7-1/20 depending on the temperature) of the rate by Caughlan et al. at the temperature range T a = 0.5-5.0. Our results are very important for the studies of stellar evolution of massive stars, supernovae and nucleosynthesis

  7. Reaction Wheel with Embedded MEMS IMU Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reaction wheels are used to stabilize satellites and to slew their orientation from object to object with precision and accuracy by varying the rotational speed of...

  8. Immune Reactions Among Marine and Other Invertebrates

    Science.gov (United States)

    Bang, Frederik B.

    1973-01-01

    Discusses the defense mechanisms and immune reaction found in invertebrates, and examines the wealth of related biological problems that need study and many of the leads that have recently been developed. (JR)

  9. Ritter Reaction in Liquid Sulfur Dioxide

    OpenAIRE

    Posevins, D; Kumpiņš, V; Turks, M

    2015-01-01

    Ritter reaction is associated with a one-pot process for amide bond formation, that involves nitrile and a group, capable of giving a relatively stable carbenium ion (originally - alcohol or alkene) in strongly ionizing acidic medium.

  10. Computed potential energy surfaces for chemical reactions

    Science.gov (United States)

    Walch, Stephen P.; Levin, Eugene

    1993-01-01

    A new global potential energy surface (PES) is being generated for O(P-3) + H2 yields OH + H. This surface is being fit using the rotated Morse oscillator method, which was used to fit the previous POL-CI surface. The new surface is expected to be more accurate and also includes a much more complete sampling of bent geometries. A new study has been undertaken of the reaction N + O2 yields NO + O. The new studies have focused on the region of the surface near a possible minimum corresponding to the peroxy form of NOO. A large portion of the PES for this second reaction has been mapped out. Since state to state cross sections for the reaction are important in the chemistry of high temperature air, these studies will probably be extended to permit generation of a new global potential for reaction.

  11. Reaction Wheel Disturbance Model Extraction Software Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reaction wheel mechanical noise is one of the largest sources of disturbance forcing on space-based observatories. Such noise arises from mass imbalance, bearing...

  12. Fluorination reaction uranium dioxide by fluorine

    International Nuclear Information System (INIS)

    Ogata, Shinji; Homma, Shunji; Koga, Jiro; Matsumoto, Shiro; Sasahira, Akira; Kawamura, Fumio

    2004-01-01

    Kinetics of the fluorination reaction of uranium dioxide is studied using un-reacted core model with shrinking particles. The model includes the film mass transfer of fluorine gas and its diffusion in the particle. The rate constants of the model are determined by fitting the experimental data for 370-450degC. The model successfully represents the fluorination in this temperature range. The rate control step is identified by examining the rate constants of the model for 300-1,800degC. For temperature range up to 900degC, the fluorination reaction is rate controlling. For over 900degC, both mechanisms of the mass transfer of fluorine and the fluorination reaction control the rate of the fluorination. With further increase of the temperature, however, the fluorination reaction becomes so fast that the mass transfer of fluorine eventually controls the rate of the fluorination. (author)

  13. Reaction rate of hydrolysis of iodine

    International Nuclear Information System (INIS)

    Miyake, Yoshikazu; Eguchi, Wataru; Adachi, Motonari

    1979-01-01

    Absorption rates of dilute iodine vapor contained in air by aqueous mixtures of sodium hydroxide and boric acid were measured using a laminar liquid jet column absorber at 298 K. Absorption rates in this system are controlled by a series of complex reactions taking place in the liquid phase. The reaction rate constant of iodine hydrolysis in the aqueous phase was determined from the absorption rates observed under the conditions that the base-catalytic hydrolysis reaction of iodine can be considered to be irreversible and that other reactions can be neglected. The absorption rates calculated theoretically with the rate constant value obtained above were in good accordance with the whole experimental data observed for a wide range of experimental conditions. (author)

  14. Reconstitution of Low Bandwidth Reaction History

    International Nuclear Information System (INIS)

    May, M.; Clancy, T.; Fittinghoff, D.; Gennaro, P.; Hagans, K.; Halvorson, G.; Lowry, M.; Perry, T.; Roberson, P.; Smith, D.; Teruya, A.; Blair, J.; Davis, B.; Hunt, E.; Emkeit, B.; Galbraith, J.; Kelly, B.; Montoya, R.; Nickel, G.; Ogle, J.; Wilson, K.; Wood, M.

    2004-01-01

    The goal of the Test Readiness Program is to transition to a 24 month test readiness posture and if approved move to an 18-month posture. One of the key components of the Test Readiness Program necessary to meet this goal is the reconstitution of the important diagnostics. Since the end of nuclear testing, the ability to field diagnostics on a nuclear test has deteriorated. Reconstitution of diagnostics before those who had experience in nuclear testing either retire or leave is essential to achieving a shorter test readiness posture. Also, the data recording systems have not been used since the end of testing. This report documents the reconstitution of one vital diagnostic: the low bandwidth reaction history diagnostic for FY04. Reaction history is one of the major diagnostics that has been used on all LLNL and LANL tests since the early days of nuclear testing. Reaction history refers to measuring the time history of the gamma and neutron output from a nuclear test. This gives direct information on the nuclear reactions taking place in the device. The reaction history measurements are one of the prime measurements the nuclear weapon scientists use to validate their models of device performance. All tests currently under consideration require the reaction history diagnostic. Thus moving to a shorter test readiness posture requires the reconstitution of the ability to make reaction history measurements. Reconstitution of reaction history was planned to be in two steps. Reaction history measurements that have been used in the past can be broadly placed into two categories. The most common type of reaction history and the one that has been performed on virtually all nuclear tests is termed low bandwidth reaction history. This measurement has a time response that is limited by the bandpass of kilometer length coaxial cables. When higher bandwidth has been required for specific measurements, fiber optic techniques have been used. This is referred to as high

  15. The reaction index and positivity ratio revisited

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Andersen, Flemming

    2008-01-01

    BACKGROUND AND OBJECTIVES: Assessing the quality of patch test preparations continues to be a challenge. 2 parameters, the reaction index (RI) and positivity ratio (PR), have been proposed as quality indicators by the Information Network of Departments of Dermatology (IVDK). The value...... of the IVDK and our department. Calculation of RI's and PR's for patch test allergens is of limited value as a measure of quality of the patch test materials, because it predominantly reflects differences in scoring and reading of patch test reactions. Further, questionable reactions (+?) may be clinically...... relevant and very important for the individual patient. Focus on standardization of patch test materials, patch test technique, and reading of patch test reactions is mandatory....

  16. Cyanohydrin reactions enhance glycolytic oscillations in yeast

    DEFF Research Database (Denmark)

    Hald, Bjørn Olav; Nielsen, Astrid Gram; Tortzen, Christian

    2015-01-01

    Synchronous metabolic oscillations can be induced in yeast by addition of glucose and removal of extracellular acetaldehyde (ACAx). Compared to other means of ACAx removal, cyanide robustly induces oscillations, indicating additional cyanide reactions besides ACA to lactonitrile conversion. Here...

  17. Reaction Wheel Disturbance Model Extraction Software Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Reaction wheel disturbances are some of the largest sources of noise on sensitive telescopes. Such wheel-induced mechanical noises are not well characterized....

  18. Reaction-diffusion with stochastic decay rates.

    Science.gov (United States)

    Lapeyre, G John; Dentz, Marco

    2017-07-26

    Understanding anomalous transport and reaction kinetics due to microscopic physical and chemical disorder is a long-standing goal in many fields including geophysics, biology, and engineering. We consider reaction-diffusion characterized by fluctuations in both transport times and decay rates. We introduce and analyze a model framework that explicitly connects microscopic fluctuations with the mescoscopic description. For broad distributions of transport and reaction time scales we compute the particle density and derive the equations governing its evolution, finding power-law decay of the survival probability, and spatially varying decay that leads to subdiffusion and an asymptotically stationary surviving-particle density. These anomalies are clearly attributable to non-Markovian effects that couple transport and chemical properties in both reaction and diffusion terms.

  19. Reaction path simulations in multicomponent materials

    International Nuclear Information System (INIS)

    Seifert, H.J.

    1999-01-01

    The CALPHAD (calculation of phase diagrams) method is used in combination with selected experimental investigations to derive reaction paths in multicomponent systems. The method is illustrated by applying computerized thermodynamic databases and suitable software to explain quantitatively the thermal degradation of precursor-derived Si-C-N ceramics and the nitridation of titanium carbide. Reaction sequences in the Si 3 N 4 -SiC-TiC x N l-x -C-N system are illustrated by graphical representation of compatibility regions and indicated reaction paths. From these results the experimentally known microstructure development of TiC reinforced Si 3 N 4 ceramics is explained and quantitative information is provided to optimize the microstructure of such materials. The concept of reaction paths for the understanding of rapid solidification processes is shown by the example of AZ type Mg casting alloys. (orig.)

  20. Kaon-nucleus reactions and hypernuclei

    International Nuclear Information System (INIS)

    Dover, C.B.

    1987-01-01

    Recent advances in hypernuclear physics and kaon-nucleus scattering are discussed, with emphasis on the spectroscopy of Λ single particle states in heavy systems, as revealed by the (π + ,K + ) reaction. 26 refs., 8 figs

  1. Reaction sintering of ceramic-metal composites

    International Nuclear Information System (INIS)

    Botta Filho, W.J.; Rodrigues, J.A.; Tomasi, R.; Pandolfelli, V.C.; Passos, J.F.S.S.; Folgueras, M.V.

    1990-01-01

    Reaction sintering experiments have been carried out in the system Al 2 O 3 -ZrAl 2 -Nb 2 O 5 with the objective of producing ceramic-metal composites of improved toughness. The sintering treatments have been done in the temperature range of 700 0 C to 1400 0 C under different conditions of vacuum and in air and argon atmospheres. The treated samples have been analysed by X-ray diffraction and analytical electron microscopy. The results are discussed in function of the degree of reaction, the development of microstructure and the densification. These results have shown that although an exchange reaction can occur to produce a composite, the control of the reaction to obtain a dense microstructure has not been possible yet. (author) [pt

  2. Habituation of orienting reaction in night terrors.

    Science.gov (United States)

    Rogozea, R; Florea-Ciocoiu, V

    1985-01-01

    A polygraphic study on resistance to habituation of the somatic (EMG), autonomic (finger vasoconstriction, galvanic skin reaction, respiration, pulse) and EEG (acoustic-evoked potential, EEG-blocking reaction) components of the orienting reaction elicited by a repetitive auditory stimulus was performed in 36 patients with night terrors and in 72 matched subjects in two control groups. The study evidenced a significantly higher resistance to habituation of the orienting reaction in patients with night terrors than in normal subjects (control group I) but significantly lower than in patients with symptomatic epilepsy (control group II). The severity of these habituation disturbances in patients with night terrors depended on the patients' age, the history of nocturnal events and their clinical form, as well as on the etiology of episodes. The habituation changes found in patients with night terrors may be ascribed to the nervous disorders of functional and/or organic nature which generated also the night terrors episodes.

  3. The Pozzolanic reaction of silica fume

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede

    2012-01-01

    Silica fume is a very important supplementary cementitious binder in High-Performance and Ultra High-Performance Concretes. Through its pozzolanic reaction the silica fume densifies the concrete micro-structure, in particular it strengthens the paste-aggregate interfacial transition zone....... In the present paper different aspects of the pozzolanic reaction of silica fume are investigated. These include chemical shrinkage, isothermal heat development and strength development. Key data for these are given and compared with theoretical calculations, and based on presented measurements the energy...... of activation of the pozzolanic reaction of silica fume is estimated. The results show that the pozzolanic reaction of silica fume has notable differences from Portland cement hydration....

  4. Medium Effects in Reactions with Rare Isotopes

    International Nuclear Information System (INIS)

    Bertulani, C A; Karakoç, M

    2012-01-01

    We discuss medium effects in knockout reactions with rare isotopes of weakly-bound nuclei at intermediate energies. We show that the poorly known corrections may lead to sizable modifications of knockout cross sections and momentum dsitributions.

  5. Nuclear reaction studies using inverse kinematics

    International Nuclear Information System (INIS)

    Shapira, D.

    1985-01-01

    Reaction studies with reversed kinematics refer to studies of nuclear reactions induced by a heavy projectile colliding with lighter target nuclei. The technique of using reversed kinematics is costly in terms of the available center-of-mass energy. Most of the projectile's energy goes into forward motion of the reaction products in the laboratory system. Examples are presented where the use of reversed kinematics techniques has provided new information on certain reaction processes. A list of kinematic properties and advantages they may afford is shown. Clearly the possible studies listed can be done without using reversed kinematics but because of the difficulty associated with some of these studies they were never performed until more energetic heavier beams have become available and the reversed kinematics technique was utilized

  6. (--SCLAREOL CONVERSION IN RITTER'S REACTION CONDITIONS

    Directory of Open Access Journals (Sweden)

    S. Kovalskaya

    2012-12-01

    Full Text Available The main products of sclareol (1 Ritter’s reaction in mild conditions are (8R,13R-Labd-14(15-en-8,13-diacetamide (2 (8R,13S-Labd-14(15-en-8,13-diacetamide (3 stereoisomeric on C13 atom and having unrearranged native diol skeleton. We present in the current communication the results of sclareol converting (1 into nitrogen-containing labdanes in the Ritter’s reaction conditions.

  7. DSMC Modeling of Flows with Recombination Reactions

    Science.gov (United States)

    2017-06-23

    Reactions S. Gimelshein, I. Wysong Air Force Research Laboratory (AFMC) AFRL/RQRC 10 E. Saturn Blvd. Edwards AFB, CA 93524-7680 Air Force Research...dimensional flows, modeling is usually con- ducted for Knudsen numbers Kn > 0.001, where the impact of recombination reactions is almost always minor, so...prac- tical applicability of the DSMC method. These methods have already been tested for reacting air flows.20 Today, modeling of gas flows at

  8. Adverse drug reactions in hospitalized Colombian children.

    Science.gov (United States)

    de Las Salas, Roxana; Díaz-Agudelo, Daniela; Burgos-Flórez, Francisco Javier; Vaca, Claudia; Serrano-Meriño, Dolores Vanessa

    2016-09-30

    The occurrence of adverse drug reactions is an important issue due to the lack of drug safety data in children. To describe the Adverse Drug Reactions in inpatient children under 6 years of age in two general pediatrics wards located in Barranquilla, Colombia. A prospective cohort study based on intensive pharmacovigilance was conducted during six months in order to monitor the emergence of Adverse Drug Reactions in inpatients children under 6 years of age with at least one medication prescribed. The study was conducted in two pediatric wards of two hospitals located in Barranquilla, Colombia. Naranjo´s Algorithm was used to evaluate imputability, the modified Hartwig and Siegel assessment scale to establish severity and the Schumock and Thornton criteria to determine preventability. Of a total of 772 monitored patients, 156 Adverse Drug Reactions were detected on 147 children. The cumulative incidence of Adverse Drug Reactions was 19.0% (147/772); the incidence density was 37.6 Adverse Drug Reactions per 1,000 patients-days (147/3,913). The frequency was higher in children under 2 years of age (12.7%). Emergence of Adverse Drug Reactions was higher in male patients (RR= 1.66; 95% CI= 1.22-2.22, p = 0.001) and in those who used systemic antibiotics (RR= 1.82; 95% CI= 1.17-2.82, p = 0.005). Adverse Drug Reactions are common among hospitalized children and represent an additional burden of morbidity and risk, particularly in those who used several medicines, including antibiotics.

  9. Coulomb dissociation studies for astrophysical thermonuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Motobayashi, T. [Dept. of Physics, Rikkyo Univ., Toshima, Tokyo (Japan)

    1998-06-01

    The Coulomb dissociation method was applied to several radiative capture processes of astrophysical interest. The method has an advantage of high experimental efficiency, which allow measurements with radioactive nuclear beams. The reactions {sup 13}N(p,{gamma}){sup 14}O and {sup 7}Be(p,{gamma}){sup 8}B are mainly discussed. They are the key reaction in the hot CNO cycle in massive stars and the one closely related to the solar neutrino problem, respectively. (orig.)

  10. Cross sections for multistep direct reactions

    International Nuclear Information System (INIS)

    Demetriou, Paraskevi; Marcinkowski, Andrzej; Marianski, Bohdan

    2002-01-01

    Inelastic scattering and charge-exchange reactions have been analysed at energies ranging from 14 to 27 MeV using the modified multistep direct reaction theory (MSD) of Feshbach, Kerman and Koonin. The modified theory considers the non-DWBA matrix elements in the MSD cross section formulae and includes both incoherent particle-hole excitations and coherent collective excitations in the continuum, according to the prescriptions. The results show important contributions from multistep processes at all energies considered. (author)

  11. Enhancing Activity for the Oxygen Evolution Reaction

    DEFF Research Database (Denmark)

    Frydendal, Rasmus; Busch, Michael; Halck, Niels Bendtsen

    2014-01-01

    Electrochemical production of hydrogen, facilitated in electrolyzers, holds great promise for energy storage and solar fuel production. A bottleneck in the process is the catalysis of the oxygen evolution reaction, involving the transfer of four electrons. The challenge is that the binding energies...... that the oxygen evolution reaction overpotential decreases by 100–300 mV for manganese oxides and 100 mV for cobalt oxides....

  12. A Hierarchy of Homodesmotic Reactions for Thermochemistry

    Science.gov (United States)

    Schleyer, Paul v. R.

    2009-01-01

    Chemical equations that balance bond types and atom hybridization to different degrees are often used in computational thermochemistry, for example, to increase accuracy when lower levels of theory are employed. We expose the widespread confusion over such classes of equations and demonstrate that the two most widely used definitions of “homodesmotic” reactions are not equivalent. New definitions are introduced and a consistent hierarchy of reaction classes (RC1 – RC5) for hydrocarbons is constructed: isogyric (RC1) ⊇ isodesmic (RC2) ⊇ hypohomodesmotic (RC3) ⊇ homodesmotic (RC4) ⊇ hyperhomodesmotic (RC5). Each of these successively conserves larger molecular fragments. The concept of isodesmic bond separation reactions is generalized to all classes in this hierarchy, providing a unique sectioning of a given molecule for each reaction type. Several ab initio and density functional methods are applied to the bond separation reactions of 38 hydrocarbons containing five or six carbon atoms. RC4 and RC5 reactions provide bond separation enthalpies with errors consistently less than 0.4 kcal mol−1 across a wide range of theoretical levels, performing significantly better than the other reaction types and far superior to atomization routes. Our recommended bond separation reactions were demonstrated by determining the enthalpies of formation (at 298 K) of 1,3,5-hexatriyne (163.7 ± 0.4 kcal mol−1), 1,3,5,7-octatetrayne (217.6 ± 0.6 kcal mol−1), the larger polyynes C10H2 through C26H2, and an infinite acetylenic carbon chain. PMID:19182999

  13. Multiple heavy-fragment breakup reactions

    International Nuclear Information System (INIS)

    Pelte, D.

    1986-01-01

    Data for heavy ion breakup reactions for projectiles between silicon 28 and argon 40 and targets between carbon 12 and zirconium 90 in the energy range 7 to 15 MeV/n are presented. The experimental method used to cope with the complexity of the exit channels in these reactions is discussed. Data on cross sections, isotopic distribution, charge distribution, energy dependence, Q-value and angular momentum of the target are discussed in relationship to model predictions

  14. Method for preparing small volume reaction containers

    Science.gov (United States)

    Retterer, Scott T.; Doktycz, Mitchel J.

    2017-04-25

    Engineered reaction containers that can be physically and chemically defined to control the flux of molecules of different sizes and charge are disclosed. Methods for constructing small volume reaction containers through a combination of etching and deposition are also disclosed. The methods allow for the fabrication of multiple devices that possess features on multiple length scales, specifically small volume containers with controlled porosity on the nanoscale.

  15. Organosilicon and organogermanium peroxides: synthesis and reactions

    International Nuclear Information System (INIS)

    Terent'ev, Alexander O; Platonov, Maksim M; Levitsky, D O; Dembitsky, V M

    2011-01-01

    The methods of synthesis and reactions of organosilicon and organogermanium peroxides are surveyed. The emphasis is placed on the studies reported in the last two decades, because in this period, the use of singlet oxygen and the Isayama–Mukaiyama reaction for the synthesis of organosilicon peroxides started. The use of these compounds in the development of antiparasitic agents is considered. The bibliography includes 220 references.

  16. Prebiotic significance of the Maillard reaction

    Science.gov (United States)

    Kolb, Vera M.; Bajagic, Milica; Zhu, William; Cody, George D.

    2005-09-01

    The Maillard reaction was studied from a prebiotic point of view. We have shown that the Maillard reaction between ribose and common amino acids occurs readily in the solid state at 65°C. The C-13 NMR spectra of the solid insoluble Maillard products of ribose and serine, or alanine or isoleucine were compared to the spectrum of the insoluble organic carbon on Murchison.

  17. Polycyclic alkaloids via transannular Mannich reactions

    DEFF Research Database (Denmark)

    Vital, Paulo; Hosseini, Masood; Shanmugham, M. S.

    2009-01-01

    The tricyclic compound 13, representing the framework of the cylindricine 4 and lepadiformine 5 alkaloids, was prepared in a single operation via the first example of a transannular Mannich reaction involving a macrocyclic diketoamine 12.......The tricyclic compound 13, representing the framework of the cylindricine 4 and lepadiformine 5 alkaloids, was prepared in a single operation via the first example of a transannular Mannich reaction involving a macrocyclic diketoamine 12....

  18. Potential of metal nanoparticles in organic reactions

    Science.gov (United States)

    Ranu, B. C.; Chattopadhyay, K.; Saha, A.; Adak, L.; Jana, R.; Bhadra, S.; Dey, R.; Saha, D.

    2008-03-01

    Palladium(0) nanoparticle has been used as efficient catalyst for (a) the stereoselective synthesis of (E)- and (Z)-2-alkene-4-ynoates and —nitriles by a simple reaction of vic-diiodo-(E)-alkenes with acrylic esters and nitriles and (b) for the allylation of active methylene compounds by allylacetate and its derivatives. Copper(0) nanoparticle catalyzes aryl-sulfur bond formation very efficiently. All these reactions are ligand-free.

  19. Extension of a Kinetic-Theory Approach for Computing Chemical-Reaction Rates to Reactions with Charged Particles

    Science.gov (United States)

    Liechty, Derek S.; Lewis, Mark J.

    2010-01-01

    Recently introduced molecular-level chemistry models that predict equilibrium and nonequilibrium reaction rates using only kinetic theory and fundamental molecular properties (i.e., no macroscopic reaction rate information) are extended to include reactions involving charged particles and electronic energy levels. The proposed extensions include ionization reactions, exothermic associative ionization reactions, endothermic and exothermic charge exchange reactions, and other exchange reactions involving ionized species. The extensions are shown to agree favorably with the measured Arrhenius rates for near-equilibrium conditions.

  20. Explore the reaction mechanism of the Maillard reaction: a density functional theory study.

    Science.gov (United States)

    Ren, Ge-Rui; Zhao, Li-Jiang; Sun, Qiang; Xie, Hu-Jun; Lei, Qun-Fang; Fang, Wen-Jun

    2015-05-01

    The mechanism of Maillard reaction has been investigated by means of density functional theory calculations in the gaseous phase and aqueous solution. The Maillard reaction is a cascade of consecutive and parallel reaction. In the present model system study, glucose and glycine were taken as the initial reactants. On the basis of previous experimental results, the mechanisms of Maillard reaction have been proposed, and the possibility for the formation of different compounds have been evaluated through calculating the relative energy changes for different steps of reaction under different pH conditions. Our calculations reveal that the TS3 in Amadori rearrangement reaction is the rate-determining step of Maillard reaction with the activation barriers of about 66.7 and 68.8 kcal mol(-1) in the gaseous phase and aqueous solution, respectively. The calculation results are in good agreement with previous studies and could provide insights into the reaction mechanism of Maillard reaction, since experimental evaluation of the role of intermediates in the Maillard reaction is quite complicated.

  1. Silicon-based sleeve devices for chemical reactions

    Science.gov (United States)

    Northrup, M. Allen; Mariella, Jr., Raymond P.; Carrano, Anthony V.; Balch, Joseph W.

    1996-01-01

    A silicon-based sleeve type chemical reaction chamber that combines heaters, such as doped polysilicon for heating, and bulk silicon for convection cooling. The reaction chamber combines a critical ratio of silicon and silicon nitride to the volume of material to be heated (e.g., a liquid) in order to provide uniform heating, yet low power requirements. The reaction chamber will also allow the introduction of a secondary tube (e.g., plastic) into the reaction sleeve that contains the reaction mixture thereby alleviating any potential materials incompatibility issues. The reaction chamber may be utilized in any chemical reaction system for synthesis or processing of organic, inorganic, or biochemical reactions, such as the polymerase chain reaction (PCR) and/or other DNA reactions, such as the ligase chain reaction, which are examples of a synthetic, thermal-cycling-based reaction. The reaction chamber may also be used in synthesis instruments, particularly those for DNA amplification and synthesis.

  2. Analysis of the Hyalinization Reaction in Otosclerosis.

    Science.gov (United States)

    Nelson, Erik G; Hinojosa, Raul

    2014-06-01

    Otosclerotic bone has been observed to penetrate the endosteal layer of the cochlea, resulting in direct contact with the soft-tissue structures of the inner ear. Sensorineural hearing loss has been observed in some, but not all, of these cases. The development of histologic changes occurring in the cochlear soft tissues at the site of otosclerotic endosteal penetration has been descriptively referred to as a hyalinization reaction. The role of the hyalinization reaction in the development of hearing loss is unknown. To evaluate the composition of these hyalinized soft tissues using immunostaining techniques. Retrospective review in a human temporal bone histopathology research laboratory of 3 specimens from patients with endosteal otosclerotic involvement. Evaluation of human temporal bone pathology findings. Human temporal bone sections with endosteal otosclerotic involvement were studied using immunostaining techniques to identify collagen I, chondroitin sulfate, and keratan sulfate deposition in the hyalinization reaction tissue. Intense collagen I staining was demonstrated within the hyalinization reaction in an onionskin-like layered fashion. In addition, dual immunofluorescence-stained sections for proteoglycans revealed both chondroitin sulfate and keratan sulfate deposition in the hyalinized tissue. The tissue of the hyalinization reaction appears to be composed of collagen I, chondroitin sulfate, and keratan sulfate, which are known to act as molecular barriers. This observation suggests that the hyalinization reaction may limit the diffusion of toxic substances produced by otosclerotic bone into the soft tissues and fluids of the cochlea.

  3. Immediate Hypersensitivity Reaction to Chemotherapeutic Agents.

    Science.gov (United States)

    Giavina-Bianchi, Pedro; Patil, Sarita U; Banerji, Aleena

    An increase by 70% in new cases of cancer is expected over the next 2 decades, with more than 8 million people dying each year from the disease, an estimated 13% of all deaths worldwide. Several new chemotherapeutic agents have been rapidly developed and many of them approved through a fast-track process. In parallel, adverse reactions to chemotherapy have increased dramatically worldwide, frequently preventing the use of first-line therapy for cancer and jeopardizing patients' treatment outcomes. The present review focuses on immediate hypersensitivity reactions (IHRs) induced by chemotherapeutic agents. We address general features of these reactions and specific characteristics of the most prevalent agents involved. On the basis of scientific evidence, we suggest classifying acute reactions to chemotherapy as toxic, systemic inflammatory response syndrome, and IHRs (anaphylactic-type reactions). IHRs to chemotherapeutic agents are unpredictable adverse reactions with potentially lethal consequences. Correct diagnosis and proper management of oncologic patients with IHRs are fundamental in order not to deprive them of the first-line treatment for their disease. In this scenario, rapid drug desensitization is a groundbreaking procedure that enables selected patients to receive the drug that induced an IHR in a safe way, minimizing the risks of anaphylaxis and treatment failure. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  4. Nanocatalysts for Suzuki cross-coupling reactions

    KAUST Repository

    Fihri, Aziz

    2011-01-01

    This critical review deals with the applications of nanocatalysts in Suzuki coupling reactions, a field that has attracted immense interest in the chemical, materials and industrial communities. We intend to present a broad overview of nanocatalysts for Suzuki coupling reactions with an emphasis on their performance, stability and reusability. We begin the review with a discussion on the importance of Suzuki cross-coupling reactions, and we then discuss fundamental aspects of nanocatalysis, such as the effects of catalyst size and shape. Next, we turn to the core focus of this review: the synthesis, advantages and disadvantages of nanocatalysts for Suzuki coupling reactions. We begin with various nanocatalysts that are based on conventional supports, such as high surface silica, carbon nanotubes, polymers, metal oxides and double hydroxides. Thereafter, we reviewed nanocatalysts based on non-conventional supports, such as dendrimers, cyclodextrin and magnetic nanomaterials. Finally, we discuss nanocatalyst systems that are based on non-conventional media, i.e., fluorous media and ionic liquids, for use in Suzuki reactions. At the end of this review, we summarise the significance of nanocatalysts, their impacts on conventional catalysis and perspectives for further developments of Suzuki cross-coupling reactions (131 references). © 2011 The Royal Society of Chemistry.

  5. N-Alkylation by Hydrogen Autotransfer Reactions.

    Science.gov (United States)

    Ma, Xiantao; Su, Chenliang; Xu, Qing

    2016-06-01

    Owing to the importance of amine/amide derivatives in all fields of chemistry, and also the green and environmentally benign features of using alcohols as alkylating reagents, the relatively high atom economic dehydrative N-alkylation reactions of amines/amides with alcohols through hydrogen autotransfer processes have received much attention and have developed rapidly in recent decades. Various efficient homogeneous and heterogeneous transition metal catalysts, nano materials, electrochemical methods, biomimetic methods, asymmetric N-alkylation reactions, aerobic oxidative methods, and even certain transition metal-free, catalyst-free, or autocatalyzed methods, have also been developed in recent years. With a brief introduction to the background and developments in this area of research, this chapter focuses mainly on recent progress and technical and conceptual advances contributing to the development of this research in the last decade. In addition to mainstream research on homogeneous and heterogeneous transition metal-catalyzed reactions, possible mechanistic routes for hydrogen transfer and alcohol activation, which are key processes in N-alkylation reactions but seldom discussed in the past, the recent reports on computational mechanistic studies of the N-alkylation reactions, and the newly emerged N-alkylation methods based on novel alcohol activation protocols such as air-promoted reactions and transition metal-free methods, are also reviewed in this chapter. Problems and bottlenecks that remained to be solved in the field, and promising new research that deserves greater future attention and effort, are also reviewed and discussed.

  6. Adverse reactions to iotroxate at intravenous cholangiography

    International Nuclear Information System (INIS)

    Nilsson, U.

    1987-01-01

    The number and type of adverse reactions to meglumine iotroxate at intravenous infusion cholangiography, performed one day prior to elective cholecystectomy, were recorded in a prospective investigation of 196 asymptomatic, anicteric patients. One hundred ml (50 mg I/ml) of contrast medium was infused over a period of 30 minutes. Only 2 minor (1%) and no severe or fatal reactions were noted. A review of the literature on the use of iotroxate in 2492 patients, including those in the present investigation, revealed a complication rate of 3.5% (3.0% minor, 0.3% moderate and 0.2% severe reactions) at infusion of iotroxate (5.0-8.0 g I) over a period of 30 to 120 minutes. This compared favourably with the 5% complication rate (4% minor, 0.5% moderate and 0.5% severe reactions) at infusion of iodoxamate and the 9% complication rate (5% minor, 1% moderate and 3% severe reactions) at infusion of ioglycamide. Irrespective of the contrast agent used, the frequency of adverse reactions at infusion was found to be 3 times lower than when equal amounts (5.0-5.6 g I) of the same medium were injected. It is concluded that, at present, infusion of iotroxate in an amount which approximates to the transportation maximum of the liver is the least toxic way of performing intravenous cholangiography with an optimum filling of the bile ducts. (orig.)

  7. Lagrangian descriptors of driven chemical reaction manifolds.

    Science.gov (United States)

    Craven, Galen T; Junginger, Andrej; Hernandez, Rigoberto

    2017-08-01

    The persistence of a transition state structure in systems driven by time-dependent environments allows the application of modern reaction rate theories to solution-phase and nonequilibrium chemical reactions. However, identifying this structure is problematic in driven systems and has been limited by theories built on series expansion about a saddle point. Recently, it has been shown that to obtain formally exact rates for reactions in thermal environments, a transition state trajectory must be constructed. Here, using optimized Lagrangian descriptors [G. T. Craven and R. Hernandez, Phys. Rev. Lett. 115, 148301 (2015)PRLTAO0031-900710.1103/PhysRevLett.115.148301], we obtain this so-called distinguished trajectory and the associated moving reaction manifolds on model energy surfaces subject to various driving and dissipative conditions. In particular, we demonstrate that this is exact for harmonic barriers in one dimension and this verification gives impetus to the application of Lagrangian descriptor-based methods in diverse classes of chemical reactions. The development of these objects is paramount in the theory of reaction dynamics as the transition state structure and its underlying network of manifolds directly dictate reactivity and selectivity.

  8. Calculation of the energetics of chemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Dunning, T.H. Jr.; Harding, L.B.; Shepard, R.L.; Harrison, R.J.

    1988-01-01

    To calculate the energetics of chemical reactions we must solve the electronic Schroedinger equation for the molecular conformations of importance for the reactive encounter. Substantial changes occur in the electronic structure of a molecular system as the reaction progresses from reactants through the transition state to products. To describe these changes, our approach includes the following three elements: the use of multiconfiguration self-consistent field wave functions to provide a consistent zero-order description of the electronic structure of the reactants, transition state, and products; the use of configuration interaction techniques to describe electron correlation effects needed to provide quantitative predictions of the reaction energetics; and the use of large, optimized basis sets to provide the flexibility needed to describe the variations in the electronic distributions. With this approach we are able to study reactions involving as many as 5--6 atoms with errors of just a few kcal/mol in the predicted reaction energetics. Predictions to chemical accuracy, i.e., to 1 kcal/mol or less, are not yet feasible, although continuing improvements in both the theoretical methodology and computer technology suggest that this will soon be possible, at least for reactions involving small polyatomic species. 4 figs.

  9. Waste-rock interactions and bedrock reactions

    International Nuclear Information System (INIS)

    White, W.B.

    1977-01-01

    The experimental program is designed to discover possible reactions between shale repository rocks and radioactive wastes. The canister can be regarded in three ways: (a) As a source of heat that modifies the mineralogy and therefore the physical properties of the surrounding rock (dry heat). (b) As a source of heat that activates reactions between minerals in the surrounding rock and slowly percolating ground water. (c) As a source of reaction materials of different composition from the surrounding rock and which therefore may react to form completely new ''minerals'' in a contact aureole around the canister. The matrix of interactions contains two composition axes. The waste compositions are defined by the various prototype waste forms usually investigated: glass, calcine, ''spent fuel'' and the ceramic supercalcine. The temperatures and pressures at which these reactions take place must be investigated. Thus each node on the ''wiring diagram'' is itself a matrix of experiments in which the T and to some extent P are varied. Experiments at higher pressure and temperature allow reactions to take place on a laboratory time scale and thus identify what could happen. These reactions are then followed downward in temperature to determine both phase boundaries and kinetic cut-offs below which equilibrium cannot be achieved on a laboratory time scale

  10. Biomixing by chemotaxis and efficiency of biological reactions: The critical reaction case

    Science.gov (United States)

    Kiselev, Alexander; Ryzhik, Lenya

    2012-11-01

    Many phenomena in biology involve both reactions and chemotaxis. These processes can clearly influence each other, and chemotaxis can play an important role in sustaining and speeding up the reaction. In continuation of our work [A. Kiselev and L. Ryzhik, "Biomixing by chemotaxis and enhancement of biological reactions," Comm. Partial Differential Equations 37, 298-318 (2012)], 10.1080/03605302.2011.589879, we consider a model with a single density function involving diffusion, advection, chemotaxis, and absorbing reaction. The model is motivated, in particular, by the studies of coral broadcast spawning, where experimental observations of the efficiency of fertilization rates significantly exceed the data obtained from numerical models that do not take chemotaxis (attraction of sperm gametes by a chemical secreted by egg gametes) into account. We consider the case of the weakly coupled quadratic reaction term, which is the most natural from the biological point of view and was left open in Kiselev and Ryzhik ["Biomixing by chemotaxis and enhancement of biological reactions," Comm. Partial Differential Equations 37, 298-318 (2012)], 10.1080/03605302.2011.589879. The result is that similarly to Kiselev and Ryzhik ["Biomixing by chemotaxis and enhancement of biological reactions," Comm. Partial Differential Equations 37, 298-318 (2012)], 10.1080/03605302.2011.589879, the chemotaxis plays a crucial role in ensuring efficiency of reaction. However, mathematically, the picture is quite different in the quadratic reaction case and is more subtle. The reaction is now complete even in the absence of chemotaxis, but the timescales are very different. Without chemotaxis, the reaction is very slow, especially for the weak reaction coupling. With chemotaxis, the timescale and efficiency of reaction are independent of the coupling parameter.

  11. A Case of a Generalized Lichenoid Tattoo Reaction

    Science.gov (United States)

    Zirwas, Matthew J.; Mosser, Joy L.

    2014-01-01

    Cutaneous reactions to tattoos have been increasing in conjunction with the rise in popularity of tattoos. While localized lichenoid reactions to tattoo inks are fairly common, generalized lichenoid reactions are relatively rare. Herein the authors present a case of a generalized lichenoid reaction to a tattoo containing only black ink. They also present a brief discussion of tattoo reactions and treatment options. PMID:25161761

  12. A detailed test of the statistical theory of nuclear reactions

    NARCIS (Netherlands)

    Spijkervet, Andreas Lambertus

    1978-01-01

    Low-energy nuclear reactions are governed by two principal kinds of mechanisms: direct reaction mechanisms characterized by reaction times of the order of the transit time of the bombarding particle through the nucleus , and compound nucelar reaction mechanisms. The reaction times ot the latter are

  13. Alkali aggregate reactions in concrete: a review of the Ethiopian ...

    African Journals Online (AJOL)

    The reaction of aggregates with alkalis in the cement to produce alkali silica reaction and alkali carbonate reaction is reviewed. The effects of the two reactions on the durability of concrete structures are highlighted. By taking samples of aggregates and cement test results, the potential of alkali silica reaction in Ethiopia is ...

  14. Wang-Landau Reaction Ensemble Method: Simulation of Weak Polyelectrolytes and General Acid-Base Reactions.

    Science.gov (United States)

    Landsgesell, Jonas; Holm, Christian; Smiatek, Jens

    2017-02-14

    We present a novel method for the study of weak polyelectrolytes and general acid-base reactions in molecular dynamics and Monte Carlo simulations. The approach combines the advantages of the reaction ensemble and the Wang-Landau sampling method. Deprotonation and protonation reactions are simulated explicitly with the help of the reaction ensemble method, while the accurate sampling of the corresponding phase space is achieved by the Wang-Landau approach. The combination of both techniques provides a sufficient statistical accuracy such that meaningful estimates for the density of states and the partition sum can be obtained. With regard to these estimates, several thermodynamic observables like the heat capacity or reaction free energies can be calculated. We demonstrate that the computation times for the calculation of titration curves with a high statistical accuracy can be significantly decreased when compared to the original reaction ensemble method. The applicability of our approach is validated by the study of weak polyelectrolytes and their thermodynamic properties.

  15. The Electronic Flux in Chemical Reactions. Insights on the Mechanism of the Maillard Reaction

    Science.gov (United States)

    Flores, Patricio; Gutiérrez-Oliva, Soledad; Herrera, Bárbara; Silva, Eduardo; Toro-Labbé, Alejandro

    2007-11-01

    The electronic transfer that occurs during a chemical process is analysed in term of a new concept, the electronic flux, that allows characterizing the regions along the reaction coordinate where electron transfer is actually taking place. The electron flux is quantified through the variation of the electronic chemical potential with respect to the reaction coordinate and is used, together with the reaction force, to shed light on reaction mechanism of the Schiff base formation in the Maillard reaction. By partitioning the reaction coordinate in regions in which different process might be taking place, electronic reordering associated to polarization and transfer has been identified and found to be localized at specific transition state regions where most bond forming and breaking occur.

  16. Quantum mechanics of chemical reactions: Recent developments in reactive scattering and in reaction path Hamiltonians

    International Nuclear Information System (INIS)

    Miller, W.H.

    1988-12-01

    Two recent developments in the theory of chemical reaction dynamics are reviewed. First, it has recently been discovered that the S- matrix version of the Kohn variational principle is free of the ''Kohn anomalies'' that have plagued other versions and prevented its general use. This has considerably simplified quantum mechanical reactive scattering calculations, which provide the rigorous characterizations of bimolecular reactions. Second, a new kind of reaction path Hamiltonian has been developed, one based on the ''least motion'' path that interpolates linearly between the reactant and product geometry of the molecule (rather than the previously used minimum energy, or ''intrinsic'' reaction path). The form of Hamiltonian which results is much simpler than the original reaction path Hamiltonian, but more important is the fact that it provides a more physically correct description of hydrogen atom transfer reactions. 44 refs., 4 figs

  17. Effects of reaction-kinetic parameters on modeling reaction pathways in GaN MOVPE growth

    Science.gov (United States)

    Zhang, Hong; Zuo, Ran; Zhang, Guoyi

    2017-11-01

    In the modeling of the reaction-transport process in GaN MOVPE growth, the selections of kinetic parameters (activation energy Ea and pre-exponential factor A) for gas reactions are quite uncertain, which cause uncertainties in both gas reaction path and growth rate. In this study, numerical modeling of the reaction-transport process for GaN MOVPE growth in a vertical rotating disk reactor is conducted with varying kinetic parameters for main reaction paths. By comparisons of the molar concentrations of major Ga-containing species and the growth rates, the effects of kinetic parameters on gas reaction paths are determined. The results show that, depending on the values of the kinetic parameters, the gas reaction path may be dominated either by adduct/amide formation path, or by TMG pyrolysis path, or by both. Although the reaction path varies with different kinetic parameters, the predicted growth rates change only slightly because the total transport rate of Ga-containing species to the substrate changes slightly with reaction paths. This explains why previous authors using different chemical models predicted growth rates close to the experiment values. By varying the pre-exponential factor for the amide trimerization, it is found that the more trimers are formed, the lower the growth rates are than the experimental value, which indicates that trimers are poor growth precursors, because of thermal diffusion effect caused by high temperature gradient. The effective order for the contribution of major species to growth rate is found as: pyrolysis species > amides > trimers. The study also shows that radical reactions have little effect on gas reaction path because of the generation and depletion of H radicals in the chain reactions when NH2 is considered as the end species.

  18. Automatic NMR-based identification of chemical reaction types in mixtures of co-occurring reactions.

    Directory of Open Access Journals (Sweden)

    Diogo A R S Latino

    Full Text Available The combination of chemoinformatics approaches with NMR techniques and the increasing availability of data allow the resolution of problems far beyond the original application of NMR in structure elucidation/verification. The diversity of applications can range from process monitoring, metabolic profiling, authentication of products, to quality control. An application related to the automatic analysis of complex mixtures concerns mixtures of chemical reactions. We encoded mixtures of chemical reactions with the difference between the (1H NMR spectra of the products and the reactants. All the signals arising from all the reactants of the co-occurring reactions were taken together (a simulated spectrum of the mixture of reactants and the same was done for products. The difference spectrum is taken as the representation of the mixture of chemical reactions. A data set of 181 chemical reactions was used, each reaction manually assigned to one of 6 types. From this dataset, we simulated mixtures where two reactions of different types would occur simultaneously. Automatic learning methods were trained to classify the reactions occurring in a mixture from the (1H NMR-based descriptor of the mixture. Unsupervised learning methods (self-organizing maps produced a reasonable clustering of the mixtures by reaction type, and allowed the correct classification of 80% and 63% of the mixtures in two independent test sets of different similarity to the training set. With random forests (RF, the percentage of correct classifications was increased to 99% and 80% for the same test sets. The RF probability associated to the predictions yielded a robust indication of their reliability. This study demonstrates the possibility of applying machine learning methods to automatically identify types of co-occurring chemical reactions from NMR data. Using no explicit structural information about the reactions participants, reaction elucidation is performed without structure

  19. Reaction chemistry of nitrogen species in hydrothermal systems: Simple reactions, waste simulants, and actual wastes

    International Nuclear Information System (INIS)

    Dell'Orco, P.; Luan, L.; Proesmans, P.; Wilmanns, E.

    1995-01-01

    Results are presented from hydrothermal reaction systems containing organic components, nitrogen components, and an oxidant. Reaction chemistry observed in simple systems and in simple waste simulants is used to develop a model which presents global nitrogen chemistry in these reactive systems. The global reaction path suggested is then compared with results obtained for the treatment of an actual waste stream containing only C-N-0-H species

  20. An Improved Protocol for the Aldehyde Olefination Reaction Using (bmim ( as Reaction Medium

    Directory of Open Access Journals (Sweden)

    Vivek Srivastava

    2013-01-01

    Full Text Available [Ru(CODCl2]/CuCl2·2H2O/LiCl catalytic system works efficiently in ionic liquid media for aldehyde olefination reaction. It offers good yield and selectivity with the added advantage of 5 times recyclability for [Ru(CODCl2] /CuCl2·2H2O/LiCl catalytic system. We also successfully reduced the reaction time from 12 hours to 9 hours for the aldehyde olefination reaction.