64,523 research outputs found
Chemoenzymatic Synthesis of Triazololactams Structurally Related to Pancratistatin
Four tricyclic lactams that structurally resemble alkaloids with the pancratistatin skeleton were synthetized from bromobenzene by a chemoenzymatic strategy. The sequence involved enzymatic dihydroxylation, efficient stereodirected oxidation of double bonds, inter- or intramolecular Huisgen cycloaddition, and a solvent-free cyclization. The complex structures were obtained in high chemical and optical purity and may be good candidates for biological testing.Fil: de la Sovera, Victoria. Universidad de la RepĂşblica. Facultad de QuĂmica. Departamento de QuĂmica Orgánica; UruguayFil: Suescun, Leopoldo. Universidad de la RepĂşblica. Laboratorio de CristalografĂa, Estado SĂłlido y Materiales; UruguayFil: Bellomo Peraza, Ana Ines. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Centro de Investigaciones en Bionanociencias ; ArgentinaFil: González, David. Universidad de la RepĂşblica. Facultad de QuĂmica. Departamento de QuĂmica Orgánica; Urugua
Dry season prevalence of contagious bovine pleuropneumonia based on postmortem examination at Hadejia Abattoir, Jigawa State
The current prevalence study of CBPP was conducted at Hadejia abattoir of Jigawa state, Nigeria using postmortem examination of CBPP lesions in lungs of cattle at slaughter. A total of 172 slaughtered cattle were examined at postmortem over the period of 3 months (March - May, 2014). Of the total, 5(2.9%) were positive for the presence of CBPP lesions. The disease was significantly higher (P<0.05) in females 4(8.3%) than in males 1(1.8%). Cattle within the rage of 3.5 – 4 years 3(9.7%) were significantly (P<0.05) infected than other age groups. Breed specific prevalence was highest 1(6.7%) in Sokoto gudali and lowest 1(3.1%) in white Fulani. This study concluded that CBPP is endemic and its prevalence is on the increase in the study area.Key words: Contagious bovine pleuropneumonia, postmortem, prevalence, vaccination, abattoir, slaughtered
Lagrange Anchor for Bargmann-Wigner equations
A Poincare invariant Lagrange anchor is found for the non-Lagrangian
relativistic wave equations of Bargmann and Wigner describing free massless
fields of spin s > 1/2 in four-dimensional Minkowski space. By making use of
this Lagrange anchor, we assign a symmetry to each conservation law.Comment: A contribution to Proceedings of the XXXI Workshop on the Geometric
Methods in Physic
Vacuum energy in the presence of a magnetic string with delta function profile
We present a calculation of the ground state energy of massive spinor fields
and massive scalar fields in the background of an inhomogeneous magnetic string
with potential given by a delta function. The zeta functional regularization is
used and the lowest heat kernel coefficients are calculated. The rest of the
analytical calculation adopts the Jost function formalism. In the numerical
part of the work the renormalized vacuum energy as a function of the radius
of the string is calculated and plotted for various values of the strength of
the potential. The sign of the energy is found to change with the radius. For
both scalar and spinor fields the renormalized energy shows no logarithmic
behaviour in the limit , as was expected from the vanishing of the heat
kernel coefficient , which is not zero for other types of profiles.Comment: 30 pages, 10 figure
Assessment of hydrogen peroxide in breath condensate as an inflammatory marker in asthmatic children
Background: Asthma is a major global public health problem. Airway inflammation is the primary cause of development and progression of asthma. Activation of inflammatory cells induces a respiratory burst resulting in the production of reactive oxygen species, such as H2O2.Objective: We sought to measure the concentration of H2O2 in exhaled breath condensate in asthmatic children and its correlation to asthmatic triggers, pulmonary function tests, treatment modalities and blood absolute white blood cell counts.Methods: Fifty asthmatic and 35 healthy children were studied. Their ages ranged from 3-14 years. Exhaled H2O2 was measured using a colorimetric assay.Results: In asthmatic children, there was a significant elevation of the mean H2O2 concentration compared to values in normal subjects( p<0.0001). Bad housing showed significant correlation to asthma severity and to number of acute asthmatic attacks. Basal spirometric pulmonary function tests, mean values showed no significant correlation to the level of H2O2 nor to treatment with inhaled steroids. Similarly, neither asthma severity nor the intake of inhaled steroids did show any significant correlation with H2O2 level.Conclusion: Exhaled H2O2 was found significantly elevated in asthmatic children. Measurement of exhaled H2O2 may help to assess airway inflammation and oxidative stress in asthmatic patients.Keywords: Hydrogen peroxide – H2O2 – exhaled breath condensate – asthma – children – oxidative stress – pulmonary function tests
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