Search results for "RADIATION"
showing 10 items of 5298 documents
Cytogenetic study of angiosarcoma of the breast.
1994
Angiosarcoma of the breast is quite rare, and the development of cutaneous angiosarcoma after segmental mastectomy and radiation therapy is even less common. A cytogenetic analysis of a mammary angiosarcoma arising in a breast after previous irradiation and segmental mastectomy for infiltrating ductal carcinoma revealed multiple clonal rearrangements involving chromosomes X, 1, 2, 3, 4, 5, 6, 7, 8, 9, 15, 17, 20, and 22. No cytogenetically analyzed angiosarcomas of the breast have been reported before. Genes Chromosom Cancer 10:210–212 (1994). © 1994 Wiley-Liss, Inc.
Eradicating Mosquitoes using Translocations
1969
CHROMOSOMAL translocations have been suggested1,2 as useful mechanisms for genetic control: translocation heterozygotes produce fewer offspring because some of their gametes do not receive a full chromosomal complement. The resultant semisterility has been observed in many plants and animals, chiefly after irradiation or other treatments of laboratory stocks but only rarely in natural populations. Spontaneous translocations originating in a field population are usually eliminated3 quickly because of the lower productivity they confer on the heterozygotes. They can become fixed in all members of a population only if it is small and isolated4.
Inherited semisterility for control of harmful insects. I. Productions of semisterility due to translocation in the mosquito,Culex pipiens L., by X-r…
1971
In Anbetracht der theoretischen und in einem Freilandexperiment bereits erwiesenen Moglichkeit der Bekampfung von Schadinsekten durch Freilassung semisteriler Tiere wurde die Produktion von Translokationen und damit verbundener Semisterilitat bei der StechmuckeCulex pipiens untersucht. Die Totalrate der erzeugten Translokationen liegt bei Stechmucken im Vergleich zuDrosophila auffallend hoch. Es besteht offenbar eine Korrelation zwischen der Gesamtlange der Chromosomen und der Translokationsrate.
Fistulae (Rectovaginal, Rectovesical)
1979
The clinical manifestations of a fistula — stool from the vagina, air from the urethra — are often difficult to recognize because the fistulous opening is hidden by the edematous and swollen mucosa. Larger defects occur particularly after radiation therapy and with Crohn’s disease.
Chronic exposure to a GSM-like signal (mobile phone) does not stimulate the development of DMBA-induced mammary tumors in rats: results of three cons…
2002
Certain epidemiological and experimental studies raised concerns about the safety of radiofrequency (RF) electromagnetic fields because of a possible increased risk of leukemia and lymphoma. In this study, an RF field used in mobile telecommunication was tested using 7,12-dimethylbenz[a]anthracene (DMBA)-induced mammary tumors in female Sprague-Dawley rats as a model for human breast cancer. Three experiments were carried out under strictly standardized conditions and were started on the same day of three consecutive years. The field consisted of a GSM-like signal (900 MHz pulsed at 217 Hz, pulse width 577 micros) of relatively low power flux density (100 microW/cm(2) +/- 3 dB) and was appl…
Detailed study of SNR G306.3–0.9 using XMM-Newton and Chandra observations
2016
Aims. We aim to study the spatial distribution of the physical and chemical properties of the X-ray emitting plasma of the supernova remnant (SNR) G306.3-0.9 in detail to obtain constraints on its ionization stage, the progenitor supernova explosion, and the age of the remnant. Methods. We used combined data from XMM-Newton and Chandra observatories to study the X-ray morphology of G306.3-0.9 in detail. A spatially resolved spectral analysis was used to obtain physical and geometrical parameters of different regions of the remnant. Spitzer infrared observations, available in the archive, were also used to constrain the progenitor supernova and study the environment in which the remnant evol…
Antennas for the detection of radio emission pulses from cosmic-ray induced air showers at the Pierre Auger Observatory.
2012
The Pierre Auger Observatory is exploring the potential of the radio detection technique to study extensive air showers induced by ultra-high energy cosmic rays. The Auger Engineering Radio Array (AERA) addresses both technological and scientific aspects of the radio technique. A first phase of AERA has been operating since September 2010 with detector stations observing radio signals at frequencies between 30 and 80 MHz. In this paper we present comparative studies to identify and optimize the antenna design for the final configuration of AERA consisting of 160 individual radio detector stations. The transient nature of the air shower signal requires a detailed description of the antenna s…
Measurement of the radiation energy in the radio signal of extensive air showers as a universal estimator of cosmic-ray energy
2016
We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8±0.7(stat)±6.7(syst) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principles calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the d…
SHOCK-CLOUD INTERACTION AND PARTICLE ACCELERATION IN THE SOUTHWESTERN LIMB OF SN 1006
2014
The supernova remnant SN 1006 is a powerful source of high-energy particles and evolves in a relatively tenuous and uniform environment despite interacting with an atomic cloud in its northwestern limb. The X-ray image of SN 1006 reveals an indentation in the southwestern part of the shock front and the H I maps show an isolated (southwestern) cloud, having the same velocity as the northwestern cloud, whose morphology fits perfectly in the indentation. We performed spatially resolved spectral analysis of a set of small regions in the southwestern nonthermal limb and studied the deep X-ray spectra obtained within the XMM-Newton SN 1006 Large Program. We also analyzed archive H I data, obtain…
Unveiling Electronic Transitions in Three Novel Chiral Azo-Compounds Using Linear and Nonlinear Circular Dichroism: A Theoretical−Experimental Study
2011
Herein, we report on the experimental and theoretically study of the linear absorption, electronic circular dichroism (ECD) spectra, as well as the two-photon absorption circular-linear dichroism measurements of three different chiral azo derivatives in dimethylsulfoxide solution. Using potential energy surfaces and frontier orbital analysis, we established the most stable conformation for each molecule and elucidated their different electronic transitions. Our theoretical calculations allowed us to unambiguously identify the spectral position of such transitions and correlate them with the spectral profiles observed in the two-photon absorption spectra. To further elucidate the characteris…