3,460 research outputs found
Pulmonary giant cells and traumatic asphyxia
A morphometrical analysis was performed to elucidate the significance of pulmonary polynuclear giant cells as a histological sign of asphyxiation. A total of 13 cases of homicidal strangulation of throttling, 8 cases of traumatic asphyxia due to chest compression and 10 control cases (cause of death: severe head injury, no signs of aspiration or other relevant pulmonary alterations, smokers and non-smokers) were investigated. The number of alveolar macrophages containing 1 or 2 nuclei and of polynuclear giant cells per microscopic field (0.000025 cm2) was estimated and a statistical evaluation was carried out. A considerable individual variation was observed in all groups with a tendency to higher numbers of cells in cases of smokers or advanced individual age. However, no significant differences were detectable in the content of alveolar macrophages and in particular of polynuclear giant cells between the asphyxiated individuals and the controls. Since polynuclear giant cells occurred in similar amounts in healthy, functionally normal lungs of non-asphyxiated individuals, the detection of such cells cannot be regarded as a reliable indicator for asphyxiation
Chemoresistance of glioblastoma cancer stem cells - much more complex than expected
Glioblastomas (GBM) are a paradigm for the investigation of cancer stem cells (CSC) in solid malignancies. The susceptibility of GBM CSC to standard chemotherapeutic drugs is controversial as the existing literature presents conflicting experimental data. Here, we summarize the experimental evidence on the resistance of GBM CSC to alkylating chemotherapeutic agents, with a special focus on temozolomide (TMZ). The data suggests that CSC are neither resistant nor susceptible to chemotherapy per se. Detoxifying proteins such as O6-methylguanine-DNA-methyltransferase (MGMT) confer a strong intrinsic resistance to CSC in all studies. Extrinsic factors may also contribute to the resistance of CSC to TMZ. These may include TMZ concentrations in the brain parenchyma, TMZ dosing schemes, hypoxic microenvironments, niche factors, and the re-acquisition of stem cell properties by non-stem cells. Thus, the interaction of CSC and chemotherapy is more complex than may be expected and it is necessary to consider these factors in order to overcome chemoresistance in the patient
Effects of a synthetic bioactive peptide on neurite growth and nerve growth factor release in chondroitin sulfate hydrogels.
Previous work has revealed robust dorsal root ganglia neurite growth in hydrogels of chondroitin sulfate. In the current work, it was determined whether addition of a synthetic bioactive peptide could augment neurite growth in these matrices via enhanced binding and sequestering of growth factors. Fluorescence recovery after photobleaching studies revealed that addition of peptide slowed nerve growth factor diffusivity in chondroitin sulfate gels, but not in control gels of hyaluronic acid. Furthermore, cultures of chick dorsal root ganglia in gels of hyaluronic acid or chondroitin sulfate revealed enhanced growth in chondroitin sulfate gels only upon addition of peptide. Taken together, these results suggest a synergistic nerve growth factor-binding activity between this peptide and chondroitin sulfate
Spectacular Role of Electron Correlation in the Hyperfine Interactions in States in Alkaline Earth Ions
The low-lying n(=3,4,5)d states alkaline earth ions are of vital
importance in a number of different physical applications. The hyperfine
structure constants of these states are characterized by unusually strong
electron correlation effects. Relativistic coupled-cluster theory has been
employed to carry out {\it ab initio} calculations of these constants. The role
of the all order core-polarization effects was found to be decisive in
obtaining good agreement of the results of our calculations with accurate
measurements. The present work is an apt demonstration of the power of the
coupled-cluster method to cope with strongly interacting configurations.Comment: Submitted to Physical Review Letters, 3 figures and 5 table
Изменение структуры и свойств покрытия на основе стали Р6М5 при воздействии импульсов лазерного излучения
Объектом исследования является покрытие на основе стали Р6М5, подверженное лазерному излучению.
Целью данной работы является исследование влияния параметров режима импульсного лазерного воздействия на структуру и свойства покрытия на основе стали Р6М5.
В процессе исследования подвергали лазерному излучению поверхностный слой образца, замеряли уровень твердости поверхностного слоя образца обработанного лазерным излучением.Das Ziel der Forschung basiert Beschichtung Stahl R6M5, Bestrahlung mit Laserstrahlung.
Das Ziel dieser Arbeit ist der Einfluß der Parameter der gepulsten Lasermode Auswirkungen auf die Struktur und die Eigenschaften der Beschichtung auf der Basis von Stahl R6M5 zu studieren.
Die Studie wurde mit Laserstrahlung mit einer Oberflächenschicht der Probe unterzogen wird, das Niveau der Härte der Oberflächenschicht der Probe mit der Laserstrahlung behandelt gemessen
Toward high-precision values of the self energy of non-S states in hydrogen and hydrogen-like ions
The method and status of a study to provide numerical, high-precision values
of the self-energy level shift in hydrogen and hydrogen-like ions is described.
Graphs of the self energy in hydrogen-like ions with nuclear charge number
between 20 and 110 are given for a large number of states. The self-energy is
the largest contribution of Quantum Electrodynamics (QED) to the energy levels
of these atomic systems. These results greatly expand the number of levels for
which the self energy is known with a controlled and high precision.
Applications include the adjustment of the Rydberg constant and atomic
calculations that take into account QED effects.Comment: Minor changes since previous versio
Conditions of the Development of Logistic Centers in Poland in the Context of European States Experiences
The article is, for the most part, the aftermath of his own examinations carried out in years 2007-2010 and concerning logistic centers development conditioning.Artykuł jest w znacznej mierze pokłosiem badań własnych autora przeprowadzonych w latach: 2007-2010 dotyczących uwarunkowań rozwoju centrów logistycznych
Cascading simulation: A critical perspective on Barack Obama‘s foreign policy during the 2008 presidential election
Entering the 2008 presidential election, Barack Obama had little to no foreign policy experience. On face, this would seem to make Obama an unlikely choice for President. Yet, he was able to defeat Hilary Clinton and John McCain, the two candidates with significant foreign policy experience. My thesis examines Barack Obama\u27s speech A World That Stands as One as a case study for understanding how simulation operates in the context of presidential campaigns. Using Robert Entman\u27s theory of cascading activation, I develop a theory of cascading simulation, arguing that image construction descends downward from the president through the media. In order to make this argument, I examine the text of the speech itself, the CNN broadcast of the event, and then newspaper recounts of the event in the New York Times and Agence France Presse. As a result, these three levels of interpretation work together to simulate foreign policy experience
Screened self-energy correction to the 2p3/2-2s transition energy in Li-like ions
We present an ab initio calculation of the screened self-energy correction
for (1s)^2 2p3/2 and (1s)^2 2s states of Li-like ions with nuclear charge
numbers in the range Z = 12-100. The evaluation is carried out to all orders in
the nuclear-strength parameter Z \alpha. This investigation concludes our
calculations of all two-electron QED corrections for the 2p3/2-2s transition
energy in Li-like ions and thus considerably improves theoretical predictions
for this transition for high-Z ions
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