1,251 research outputs found
Laser Doppler instrument measures fluid velocity without reference beam
Fluid velocity is measured by focusing laser beam on moving fluid and measuring Doppler shift in frequency which results when radiation is scattered by particles either originally present or deliberately injected into moving fluid
Investigation of air-flow velocity by laser backscatter
Laser light backscatter investigation of air flow velocity in contaminated atmospheres for application to clear air turbulence detector
New approaches to the management of adult acute lymphoblastic leukemia
Traditional treatment regimens for adult acute lymphoblastic leukemia, including allogeneic hematopoietic cell transplantation, result in an overall survival of about 40%, a figure hardly comparable with the extraordinary 80-90% cure rate currently reported in children. When translated to the adult setting, modern pediatric-type regimens improve the survival to about 60% in young adults. The addition of tyrosine kinase inhibitors for patients with Philadelphia chromosome positive disease and the measurement of minimal residual disease to guide risk stratification and post-remission approaches has led to further improvements in outcomes. Relapsed disease and treatment toxicity - sparing no patient but representing a major concern especially in the elderly - are the most critical current issues awaiting further therapeutic advancement. Recently, there has been considerable progress in understanding the disease biology, specifically the Philadelphia-like signature as well as other high-risk subgroups. In addition, there are several new agents that will undoubtedly contribute to further improvement in the current outcomes. The most promising agents are new the monoclonal antibodies, immunomodulators, and chimeric antigen receptor T cells and, to a lesser extent, several new drugs targeting key molecular pathways involved in leukemic cell growth and proliferation. This review examines the evidence supporting the increasing role of the new therapeutic tools and treatment options in different disease subgroups, including frontline and relapsed/refractory disease. It is now possible to define the best individual approach based on to the emerging concepts of precision medicine
Extremely Low Loss Phonon-Trapping Cryogenic Acoustic Cavities for Future Physical Experiments
Low loss Bulk Acoustic Wave devices are considered from the point of view of
the solid state approach as phonon-confining cavities. We demonstrate effective
design of such acoustic cavities with phonon-trapping techniques exhibiting
extremely high quality factors for trapped longitudinally-polarized phonons of
various wavelengths. Quality factors of observed modes exceed 1 billion, with a
maximum -factor of 8 billion and product of at
liquid helium temperatures. Such high sensitivities allow analysis of intrinsic
material losses in resonant phonon systems. Various mechanisms of phonon losses
are discussed and estimated
SU(3) Breaking in Hyperon Beta Decays: a Prediction for Xi^0 -> Sigma^+ e nu-bar
On the basis of a previous analysis of hyperon semi-leptonic decay data, a
prediction is presented for g_1/f_1 in the Xi^0 -> Sigma^+ e nu-bar beta-decay.
The analysis takes into account SU(3) breaking in this sector via the inclusion
of mass-driven corrections. A rather precise measurement of the above channel
by the KTeV experiment at Fermilab will shortly be available. Since the
dependence on the SU(3) parameters, F and D, is identical to that of the
neutron beta-decay, such a measurement will provide a rather stringent test of
SU(3) and the models used to describe its violation in these decays. The
prediction given here for the above decay is g_1/f_1=1.17, which leads to a
rate of 0.80 x 10^6 s^-1 and thus a branching fraction of 2.3 x 10^-4.Comment: LaTeX, 7 pages, uses acromake, cite and topcapt packages.
Non-printing extended ascii characters replaced plus minor correction
Isospin Breaking in Neutron -decay and SU(3) Violation in Semi-leptonic Hyperon Decays
Present precision measurements of the neutron life time lead to a CKM matrix
element which is three standard deviations off the value inferred
from heavy quark decays etc. We investigate the possibility whether
isospin-breaking effects in the neutron-to-proton vector current transition
matrix element could eventually close this gap.
For that we calculate in chiral perturbation theory the effect of pion and kaon
loops on the matrix element taking into account the mass
differences of the charged and neutral mesons. We find a negligibly small
isospin-breaking effect of . The crucial
quantity in the analysis of neutron beta-decay precision measurements is thus
the radiative correction term . Furthermore, we calculate in heavy
baryon chiral perturbation theory the SU(3) breaking effects on the vector
transition charges of weak semi-leptonic hyperon decays. We find for these
quantities channel-dependent relative deviations from the SU(3) limit which
range from -10% to .Comment: 6 pages, 1 figure, to be published in Physical Review C (brief
report
Individual training at the undergraduate level to promote competence in breaking bad news in oncology
Training medical students in breaking bad news (BBN) in oncology may be key to improve patient care in an area where many physicians tend to be uncomfortable. Given the lack of evidence in the literature, this study aimed to assess empirically the impact of 2 teaching strategies to prepare students for the task of BBN in oncology: one-to-one simulated patient (SP) training with individual feedback (intervention group) vs small-group SP training with collective feedback (comparison group).
Fourth-year students (N = 236) were randomly assigned to the intervention or comparison group. The SP videotaped interviews were analyzed with respect to BBN communication performance, rated using the Calgary-Cambridge checklist of teaching objectives for BBN; verbal interaction behaviors, coded with the Roter interaction analysis system; and 7 nonverbal behaviors.
Students in the intervention group scored significantly higher after than before the training on the overall evaluation of the interview (P < .001) as well as on process skills (P < .001); they also obtained significantly higher scores compared to students in the comparison group on the overall evaluation of the interview (P < .001) and on process skills (P < .001).
This study supports an individualized BBN teaching strategy and contributes to efforts to find the best way to train and reach the largest number of future physicians to improve communication competences in oncology
La industria petroquímica
La industria petroquímica es un sector de I la industria química que utiliza derivados del petróleo y gas natural como materias primas. Esta definición es sumamente simple y no da lugar a confusiones, pero para ilustrar el campo que corresponde a este sector industrial, en el cuadro N° 1 se indica una clasificación de los principales productos de las industrias petrolera y petroquímica. En la columna A se ubican los productos naturales (petróleo crudo y gas natural) a partir de los cuales se obtiene una serie de derivados utilizados como combustibles, lubricantes, solventes, etc.; parte de los cuales son utilizados como materias primas para la industria petroquímica (columna B). A partir de ellos se obtienen los productos petroquímicos básicos (columna C ). Estos a su vez se utilizan para la elaboración de productos petroquímicos intermedios (columna D ), con los cuales se pueden obtener los productos petroquímieos finales (columna E ): agroquímicos (fertilizantes y plaguicidas), plásticos, fibras sintéticas, cauchos sintéticos, detergentes, etc.Universidad Nacional de La Plat
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