693 research outputs found
Type O pure radiation metrics with a cosmological constant
In this paper we complete the integration of the conformally flat pure
radiation spacetimes with a non-zero cosmological constant , and , by considering the case . This is a
further demonstration of the power and suitability of the generalised invariant
formalism (GIF) for spacetimes where only one null direction is picked out by
the Riemann tensor. For these spacetimes, the GIF picks out a second null
direction, (from the second derivative of the Riemann tensor) and once this
spinor has been identified the calculations are transferred to the simpler GHP
formalism, where the tetrad and metric are determined. The whole class of
conformally flat pure radiation spacetimes with a non-zero cosmological
constant (those found in this paper, together with those found earlier for the
case ) have a rich variety of subclasses with zero,
one, two, three, four or five Killing vectors
Invariant classification and the generalised invariant formalism: conformally flat pure radiation metrics, with zero cosmological constant
Metrics obtained by integrating within the generalised invariant formalism
are structured around their intrinsic coordinates, and this considerably
simplifies their invariant classification and symmetry analysis. We illustrate
this by presenting a simple and transparent complete invariant classification
of the conformally flat pure radiation metrics (except plane waves) in such
intrinsic coordinates; in particular we confirm that the three apparently
non-redundant functions of one variable are genuinely non-redundant, and easily
identify the subclasses which admit a Killing and/or a homothetic Killing
vector. Most of our results agree with the earlier classification carried out
by Skea in the different Koutras-McIntosh coordinates, which required much more
involved calculations; but there are some subtle differences. Therefore, we
also rework the classification in the Koutras-McIntosh coordinates, and by
paying attention to some of the subtleties involving arbitrary functions, we
are able to obtain complete agreement with the results obtained in intrinsic
coordinates. In particular, we have corrected and completed statements and
results by Edgar and Vickers, and by Skea, about the orders of Cartan
invariants at which particular information becomes available.Comment: Extended version of GRG publication, with some typos etc correcte
Obtaining a class of Type O pure radiation metrics with a cosmological constant, using invariant operators
Using the generalised invariant formalism we derive a class of conformally
flat spacetimes whose Ricci tensor has a pure radiation and a Ricci scalar
component. The method used is a development of the methods used earlier for
pure radiation spacetimes of Petrov types O and N respectively. In this paper
we demonstrate how to handle, in the generalised invariant formalism,
spacetimes with isotropy freedom and rich Killing vector structure. Once the
spacetimes have been constructed, it is straightforward to deduce their
Karlhede classification: the Karlhede algorithm terminates at the fourth
derivative order, and the spacetimes all have one degree of null isotropy and
three, four or five Killing vectors.Comment: 29 page
Literacy and primary school expansion in Portugal: 1940â62
In 1940, the Portuguese government approved a massive primary school construction
plan that projected a 60% increase in the number of primary schools. Based on the
collection of a new dataset, we describe literacy levels in Portugal prior to the plan as
well as the planâs strategy regarding the location of schools. We then estimate the
causal impact of the increase in the number of schools between 1940 and the early 60s
on enrolment and literacy, all at the county level. We conclude the increase in the
number of schools was responsible for 80% of the increase in enrolment and 13% of
the increase in the literacy rate of the affected cohorts
Encapsulation efficiency of Lactobacillus plantarum microencapsulado in Acrycoat S100
Several studies have attributed health benefits to
probiotics, as the contribution to intestinal microflora
activity (Khan et al. 2013). However, adverse conditions
in gastrointestinal transit can reduce the viability of
probiotics as Lactobacillus plantarum.
Acrycoat S100 is a co-polymer from methacrylic acid
and methyl methacrylate, water insoluble and soluble in
pH â„ 7. Therefore, microencapsulation of probiotic in
Acrycoat S100 could allow microorganism protection
until it reach the intestine. The objective of this study
was to determine the encapsulation efficiency of L.
plantarum microencapsulated in Acrycoat S100.info:eu-repo/semantics/publishedVersio
Elevated hypercoagulability markers in hemoglobin sc disease
Hemoglobin SC disease is a very prevalent hemoglobinopathy, however very little is known specifically about this condition. There appears to be an increased risk of thromboembolic events in hemoglobin SC disease, but studies evaluating the hemostatic alterations are lacking. We describe a cross-sectional observational study evaluating coagulation activation markers in adult hemoglobin SC patients, in comparison with sickle cell anemia patients and healthy controls. A total of 56 hemoglobin SC and 39 sickle cell anemia patients were included in the study, all in steady state, and 27 healthy controls. None of the patients were in use of hydroxyurea. Hemoglobin SC patients presented a significantly up-regulated relative expression of tissue factor, as well as elevations in thrombin-antithrombin complex and D-dimer, in comparison to controls (p<0.01). Hemoglobin SC patients presented lower tissue factor expression, and thrombin-antithrombin complex and D-dimer levels when compared to sickle cell anemia patients (p<0.05). Endothelial activation (soluble thrombomodulin and soluble vascular cell adhesion molecule-1), and inflammation (tumor necrosis factor-alpha) markers were both significantly elevated in hemoglobin SC patients when compared to controls, being as high as the levels seen in sickle cell anemia. Overall, in hemoglobin SC patients, higher hemolytic activity and inflammation were associated with a more intense activation of coagulation, and hemostatic activation was associated with two very prevalent chronic complications seen in hemoglobin SC disease: retinopathy and osteonecrosis. In summary, our results demonstrate that hemoglobin SC patients present a hypercoagulable state, although this manifestation was not as intense as that seen in sickle cell anemia.Hemoglobin SC disease is a very prevalent hemoglobinopathy, however very little is known specifically about this condition. There appears to be an increased risk of thromboembolic events in hemoglobin SC disease, but studies evaluating the hemostatic alte1004466471CNPQ - CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICOFAPESP - FUNDAĂĂO DE AMPARO Ă PESQUISA DO ESTADO DE SĂO PAULOsem informaçãosem informaçã
Studying conformally flat spacetimes with an elastic stress energy tensor using 1+3 formalism
Conformally flat spacetimes with an elastic stress energy tensor given by a
diagonal trace-free anisotropic pressure tensor are investigated using 1+3
formalism. We show how the null tetrad Ricci components are related to the
pressure components and energy density. The 1+3 Bianchi and Jacobi identities
and Einstein field equations are written for this particular case. In general
the commutators must be considered since they supply potentially new
information on higher order derivatives of the 1+3 quantities. We solve the
system for the non rotating case which consist of ODEs of a spatial coordinate
Determination of tranexamic acid in human plasma by UHPLC coupled with tandem mass spectrometry targeting sub-microgram per milliliter levels
Tranexamic acid (TXA) is an antifibrinolytic drug, with the ability to inhibit lysine binding at plasminogen receptors, used in adult trauma patients with on-going or at risk of significant haemorrhage. To understand the pharmacokinetics and pharmacodynamics of this drug in variable age groups undergoing surgeries with high blood loss, effective methods for determination of TXA in biological samples at sub-ÎŒgâŻmLâ1 are still required. We describe herein the development and validation of a method based on ultra-high performance liquid chromatography coupled to triple quadrupole-tandem mass spectrometry to quantify TXA in human plasma. An inexpensive, simple and efficient sample clean-up was implemented, not requiring matrix-matching calibration. Sample preparation consisted in protein precipitation using acetonitrile containing 0.5% (v/v) formic acid, followed by hydrophilic interaction based chromatographic separation, with elution in isocratic mode using a combination of acetonitrile and water (75:25, v/v), with quantification of TXA based on selected reaction monitoring. Good linearity was achieved (r2âŻ>âŻ0.997) for TXA concentrations ranging from 30 to 600âŻngâŻmLâ1, with LOD of 18âŻngâŻmLâ1 in plasma. The developed method proved to be selective, sensitive, accurate (96.4â105.7% of nominal values) and precise (RSDâŻâ€âŻ4.5%). TXA was found to be stable in plasma extracts standing 24âŻh at room temperature (20âŻÂ°C) or in the autosampler, and after three freeze-thawing cycles. Mean recovery values of TXA spiked plasma samples were â„91.9%. No significant matrix effects were observed. The proposed methodology was successfully applied to the clinical study of plasma samples recovered during scoliosis surgery of pediatric patients pretreatment with TXA.info:eu-repo/semantics/publishedVersio
Monitoring Of Bcr-abl Levels In Chronic Myeloid Leukemia Patients Treated With Imatinib In The Chronic Phase - The Importance Of A Major Molecular Response
Background: Real time PCR has become the most common technique to monitor BCR-ABL transcript levels of patients treated with kinase inhibitors. The aim of this study was to evaluate BCR-ABL levels of chronic myeloid leukemia patients treated with imatinib in the chronic phase and correlate the response to therapy and event-free survival. Methods: BCR-ABL levels were measured in peripheral blood cell samples using Real time PCR at diagnosis and then every 3 months after starting therapy with imatinib. Major molecular response was defined as a three-log reduction from the standardized baseline value. Major molecular response values were adjusted to international scale using a conversion factor of 1.19. The results are reported as a BCR-ABL/ABL ratio (%). Results: Hematological, major cytogenetic and complete cytogenetic responses were achieved by 57 (95%), 45 (75%) and 38 (63%) patients, respectively. Twenty-four out of sixty patients achieved a major molecular response (40%) in a median time of 8.5 months. Overall survival and event free survival were higher for patients with (100%) versus patients without (77%) a complete cytogenetic response (p-value = 0.01) at 48 months. Patients with complete cytogenetic response and major molecular response had a higher event free survival compared to patients with complete cytogenetic response but without major molecular response (p-value = 0.007). Conclusion: In conclusion, the prognostic impact of achieving complete cytogenetic response and a major molecular response and also the importance of molecular monitoring in the follow-up of chronic myeloid leukemia patients were demonstrated.333211215Melo, J.V., The molecular biology of chronic myeloid leukaemia (1996) Leukemia, 10 (5), pp. 751-756Wang, L., Pearson, K., Pillitteri, L., Ferguson, J.E., Clark, R.E., Serial monitoring of BCR-ABL by peripheral blood real-time polymerase chain reaction predicts the marrow cytogenetic response to imatinib mesylate in chronic myeloid leukaemia (2002) Br J Haematol, 118 (3), pp. 771-777Muller, M.C., Gattermann, N., Lahaye, T., Deininger, M.W., Berndt, A., Fruehauf, S., Dynamics of BCR-ABL mRNA expression in firstline therapy of chronic myelogenous leukemia patients with imatinib or interferon alpha/ara-C (2003) Leukemia, 17 (12), pp. 2392-2400Branford, S., Hughes, T.P., Rudzki, Z., Monitoring chronic myeloid leukaemia therapy by real-time quantitative PCR in blood is a reliable alternative to bone marrow cytogenetics (1999) Br J Haematol, 107 (3), pp. 587-599Radich, J.P., Gooley, T., Bryant, E., Chauncey, T., Clift, R., Beppu, L., The significance of bcr-abl molecular detection in chronic myeloid leukemia patients late, 18 months or more after transplantation (2001) Blood, 98 (6), pp. 1701-1707Hughes, T.P., Kaeda, J., Branford, S., Rudzki, Z., Hochhaus, A., Hensley, M.L., Frequency of major molecular responses to imatinib or interferon-alpha plus cytarabine in newly diagnosed chronic myeloid leukemia (2003) N Engl J Med, 349 (15), pp. 1423-1432Press, R.D., Love, Z., Tronnes, A.A., Yang, R., Tran, T., Mongoue- tchokote, S., BCR-ABL mRNA levels at and after the time of a complete cytogenetic response predict the duration of CCR in imatinib mesylate-treated patients with CML (2006) Blood, 107 (11), pp. 4250-4256Cortes, J., Talpaz, M., O'Brien, S., Jones, D., Luthra, R., Shan, J., Molecular responses in patients with chronic myelogenous leukemia in chronic phase treated with imatinib mesylate (2005) Clin Cancer Res, 11 (9), pp. 3425-3432Iacobucci, I., Saglio, G., Rosti, G., Testoni, N., Pane, F., Amabile, M., Achieving a major molecular response at the time of a complete cytogenetic response (CCgR) predicts a better duration of CCgR in imatinib-treated chronic myeloid leukemia patients (2006) Clin Cancer Res, 12 (10), pp. 3037-3042Baccarani, M., Saglio, G., Goldman, J., Hochhaus, A., Simonsson, B., Appelbaum, F., Evolving concepts in the management of chronic myeloid leukemia: Recommendations from an expert panel on behalf of the European LeukemiaNet (2006) Blood, 108 (6), pp. 1809-1820Hughes, T., Deininger, M., Hochhaus, A., Branford, S., Radich, J., Kaeda, J., Monitoring CML patients responding to treatment with tyrosine kinase inhibitors: Review and recommendations for harmonizing current methodology for detecting BCR-ABL transcripts and kinase domain mutations and for expressing results (2006) Blood, 108 (1), pp. 28-37Branford, S., Cross, N.C., Hochhaus, A., Radich, J., Saglio, G., Kaeda, J., Rationale for the recommendations for harmonizing current methodology for detecting BCR-ABL transcripts in patients with chronic myeloid leukaemia (2006) Leukemia, 20 (11), pp. 1925-1930Cortes, J., Baccarani, M., Fea, G., (2008) A Phase III, Randomized, Openlabel Study of 400 Mg Versus 800 Mg of Imatinib Mesylate (IM) in Patients With Newly Diagnosed, Previously Untreated Chronic Myeloid Leukemia in Chronic Phase (CML-CP), Using Molecular Endpoints: One Year Results of TOPS (Tyrosine Kinase Inhibitor Optimization and Selectivity) Study, , 50th ASH Annual Meeting and Exposition Online program and Abstracts. San Francisco, CABranford, S., Fletcher, L., Cross, N.C., Muller, M.C., Hochhaus, A., Kim, D.W., Desirable performance characteristics for BCR-ABL measurement on an international reporting scale to allow consistent interpretation of individual patient response and comparison of response rates between clinical trials (2008) Blood, 112 (8), pp. 3330-3338O'Brien, S.G., Guilhot, F., Larson, R.A., Gathmann, I., Baccarani, M., Cervantes, F., Imatinib compared with interferon and lowdose cytarabine for newly diagnosed chronic-phase chronic myeloid leukemia (2003) N Engl J Med, 348 (11), pp. 994-1004Marin, D., Milojkovic, D., Olavarria, E., Khorashad, J.S., de Lavallade, H., Reid, A.G., European LeukemiaNet criteria for failure or suboptimal response reliably identify patients with CML in early chronic phase treated with imatinib whose eventual outcome is poor (2008) Blood, 112 (12), pp. 4437-444
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