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1.
Strahlenther Onkol ; 200(6): 544-548, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38180493

RESUMEN

Recent advancements in large language models (LMM; e.g., ChatGPT (OpenAI, San Francisco, California, USA)) have seen widespread use in various fields, including healthcare. This case study reports on the first use of LMM in a pretreatment discussion and in obtaining informed consent for a radiation oncology treatment. Further, the reproducibility of the replies by ChatGPT 3.5 was analyzed. A breast cancer patient, following legal consultation, engaged in a conversation with ChatGPT 3.5 regarding her radiotherapy treatment. The patient posed questions about side effects, prevention, activities, medications, and late effects. While some answers contained inaccuracies, responses closely resembled doctors' replies. In a final evaluation discussion, the patient, however, stated that she preferred the presence of a physician and expressed concerns about the source of the provided information. The reproducibility was tested in ten iterations. Future guidelines for using such models in radiation oncology should be driven by medical professionals. While artificial intelligence (AI) supports essential tasks, human interaction remains crucial.


Asunto(s)
Inteligencia Artificial , Neoplasias de la Mama , Consentimiento Informado , Humanos , Femenino , Neoplasias de la Mama/radioterapia , Relaciones Médico-Paciente , Oncología por Radiación , Persona de Mediana Edad
2.
Phys Rev Lett ; 125(2): 021301, 2020 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-32701326

RESUMEN

On January 14, 2019, the Major Atmospheric Gamma Imaging Cherenkov telescopes detected GRB 190114C above 0.2 TeV, recording the most energetic photons ever observed from a gamma-ray burst. We use this unique observation to probe an energy dependence of the speed of light in vacuo for photons as predicted by several quantum gravity models. Based on a set of assumptions on the possible intrinsic spectral and temporal evolution, we obtain competitive lower limits on the quadratic leading order of speed of light modification.

3.
Ann Surg Oncol ; 27(5): 1700-1707, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31873929

RESUMEN

BACKGROUND: While "no tumour on ink" is an accepted margin width for R0 resection in primary surgery, it's unclear if it's oncologically safe after neoadjuvant chemotherapy (NAC). Only limited data demonstrate that surgery within new margins in cases of a pathological complete response (pCR) is safe. We therefore investigated the influence of different margins and pCR on local recurrence and survival rates after NAC. METHODS: We retrospectively analysed data of 406 women with invasive breast cancer, treated with NAC and breast-conserving therapy between 1994 and 2014 in two certified Austrian breast health centres. We compared R ≤ 1 mm, R > 1 mm and RX (pCR) for local recurrence-free survival (LRFS), disease-free survival (DFS) and overall survival (OS). RESULTS: After a median follow-up of 84.3 months, the 5-year LRFS (R ≤ 1 mm: 94.2%, R > 1 mm: 90.6%, RX: 95.0%; p = 0.940), the 5-year DFS (R ≤ 1 mm: 71.9%, R > 1 mm: 74.1%, RX: 87.2%; p = 0.245) and the 5-year OS (R ≤ 1 mm: 85.1%, R > 1 mm: 88.0%, RX: 96.4%; p = 0.236) did not differ significantly between narrow, wide, nor RX resections. Regarding DFS and OS, a negative nodal status reduced the hazard ratio significantly. CONCLUSION: There is no significant difference in LRFS, DFS and OS comparing close, wide or unknown margins after pCR. We suggest that resection in new margins after NAC is safe according to "no tumour on ink". Resection of the clipped area in cases of pCR is emphasized.


Asunto(s)
Neoplasias de la Mama/terapia , Quimioterapia Adyuvante , Márgenes de Escisión , Mastectomía Segmentaria , Recurrencia Local de Neoplasia/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Austria/epidemiología , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Terapia Combinada , Femenino , Humanos , Persona de Mediana Edad , Recurrencia Local de Neoplasia/mortalidad , Estadificación de Neoplasias , Cuidados Preoperatorios , Pronóstico , Estudios Retrospectivos , Análisis de Supervivencia , Adulto Joven
4.
Science ; 346(6213): 1080-4, 2014 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-25378461

RESUMEN

Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) telescopes, revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20% of the gravitational radius of its central black hole. We suggest that the emission is associated with pulsar-like particle acceleration by the electric field across a magnetospheric gap at the base of the radio jet.

5.
Phys Med Biol ; 54(8): 2585-95, 2009 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-19349657

RESUMEN

Pulsed dose rate brachytherapy (PDR) was compared to external beam radiation therapy (EBRT) in the case of breast cancer. The benefits were figured out by evaluation of dosimetric parameters and calculating the normal tissue complication probability (NTCP). PDR plans were set up for five randomly chosen left-sided breast cancer patients delivering a total dose of 50.4 Gy to the target (dose rate 0.8 Gy h(-1)). For EBRT five left-sided breast cancer patients were planned using 3D-conformal tangential photon beams with a prescribed total dose of 50 Gy (2 Gy/fraction) to the total breast volume. For plan ranking and NTCP calculation the physical dose was first converted into the biologically effective dose (BED) and then into the normalized total dose (NTD) using the linear quadratic model with an alpha/beta ratio of 3 Gy. In PDR the relative effectiveness (RE) was calculated for each dose bin of the differential dose volume histogram to get the BED. NTCPs were calculated for the ipsilateral lung and the heart as contoured on CT slices based on the Lyman model and the Kutcher reduction scheme. Dosimetric parameters as V(th) (percentage of the total volume exceeding a threshold dose) and Jackson's f(dam) (fraction of the organ damaged) were also used to figure out the benefits. The comparison of calculated NTCPs in PDR and EBRT showed no difference between these two modalities. All values were below 0.01%. f(dam) derived from EBRT was always higher (mean value 8.95% versus 1.21% for the lung). The mean V(10) and V(20) of the lung related to BED were 6.32% and 1.72% for PDR versus 11.72% and 9.59% for EBRT. When using dosimetric parameters as V(th) and f(dam), PDR was mostly superior to EBRT in respect of sparing normal tissues. NTCP calculation as a single method of modality ranking showed a lack of information, especially when normal tissue was exposed to low radiation doses.


Asunto(s)
Braquiterapia/métodos , Neoplasias de la Mama/radioterapia , Braquiterapia/efectos adversos , Corazón/efectos de la radiación , Humanos , Pulmón/efectos de la radiación , Probabilidad , Radiometría , Dosificación Radioterapéutica
6.
Science ; 322(5905): 1221-4, 2008 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-18927358

RESUMEN

One fundamental question about pulsars concerns the mechanism of their pulsed electromagnetic emission. Measuring the high-end region of a pulsar's spectrum would shed light on this question. By developing a new electronic trigger, we lowered the threshold of the Major Atmospheric gamma-ray Imaging Cherenkov (MAGIC) telescope to 25 giga-electron volts. In this configuration, we detected pulsed gamma-rays from the Crab pulsar that were greater than 25 giga-electron volts, revealing a relatively high cutoff energy in the phase-averaged spectrum. This indicates that the emission occurs far out in the magnetosphere, hence excluding the polar-cap scenario as a possible explanation of our measurement. The high cutoff energy also challenges the slot-gap scenario.

7.
Science ; 320(5884): 1752-4, 2008 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-18583607

RESUMEN

The atmospheric Cherenkov gamma-ray telescope MAGIC, designed for a low-energy threshold, has detected very-high-energy gamma rays from a giant flare of the distant Quasi-Stellar Radio Source (in short: radio quasar) 3C 279, at a distance of more than 5 billion light-years (a redshift of 0.536). No quasar has been observed previously in very-high-energy gamma radiation, and this is also the most distant object detected emitting gamma rays above 50 gigaelectron volts. Because high-energy gamma rays may be stopped by interacting with the diffuse background light in the universe, the observations by MAGIC imply a low amount for such light, consistent with that known from galaxy counts.

8.
Science ; 312(5781): 1771-3, 2006 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-16709745

RESUMEN

Microquasars are binary star systems with relativistic radio-emitting jets. They are potential sources of cosmic rays and can be used to elucidate the physics of relativistic jets. We report the detection of variable gamma-ray emission above 100 gigaelectron volts from the microquasar LS I 61 + 303. Six orbital cycles were recorded. Several detections occur at a similar orbital phase, which suggests that the emission is periodic. The strongest gamma-ray emission is not observed when the two stars are closest to one another, implying a strong orbital modulation of the emission or absorption processes.

9.
Cell ; 107(2): 183-94, 2001 Oct 19.
Artículo en Inglés | MEDLINE | ID: mdl-11672526

RESUMEN

In Drosophila, distinct mechanisms orient asymmetric cell division along the apical-basal axis in neuroblasts and along the anterior-posterior axis in sensory organ precursor (SOP) cells. Here, we show that heterotrimeric G proteins are essential for asymmetric cell division in both cell types. The G protein subunit G(alpha)i localizes apically in neuroblasts and anteriorly in SOP cells before and during mitosis. Interfering with G protein function by G(alpha)i overexpression or depletion of heterotrimeric G protein complexes causes defects in spindle orientation and asymmetric localization of determinants. G(alpha)i is colocalized and associated with Pins, a protein that induces the release of the betagamma subunit and might act as a receptor-independent G protein activator. Thus, asymmetric activation of heterotrimeric G proteins by a receptor-independent mechanism may orient asymmetric cell divisions in different cell types.


Asunto(s)
Proteínas de Ciclo Celular , División Celular , Proteínas de Drosophila , Proteínas de Unión al GTP/metabolismo , Sistema Nervioso/metabolismo , Animales , Animales Modificados Genéticamente , Proteínas del Citoesqueleto/metabolismo , Drosophila , Proteínas de Unión al GTP/fisiología , Proteínas de Unión al GTP Heterotriméricas/metabolismo , Proteínas de Insectos/metabolismo , Microscopía Fluorescente , Mitosis , Modelos Biológicos , Mutación , Neuronas/metabolismo , Neuropéptidos , Unión Proteica , Transgenes
12.
Wien Med Wochenschr ; 149(13): 388-91, 1999.
Artículo en Alemán | MEDLINE | ID: mdl-10568022

RESUMEN

Even in present times and given the current state of medical science, an influenza pandemic may be expected to occur in addition to the usual annual epidemic of the disease. A pandemic is defined as a concentrated worldwide occurrence of a disease within a short period. Such a pandemic has been registered three times in this century. The influenza epidemic of 1918 to 1919 ("Spanish flu") killed 20 to 40 million people. A similar pandemic occurred in 1957 to 1958 (Hong Kong) and in 1968 (Asia). Although the current state of medicine is such that the high morbidity and mortality of 1918 is unlikely to recur, adequate preventive measures are warranted in health care as well as in social and political fields. In the event of such a pandemic, a large number of persons in Austria may be expected to be affected by the disease. In contrast to other countries, a detailed plan of prevention does not exist in Austria at the present time. A sudden influenza pandemic would give rise to a number of grave problems in the medical field (increase in mortality rates) as well as in social and political areas (maintaining the infrastructure of the country). In light of this fact it appears necessary to investigate the possibility of an influenza pandemic and to take suitable precautionary measures.


Asunto(s)
Brotes de Enfermedades/prevención & control , Urgencias Médicas , Gripe Humana/prevención & control , Salud Pública , Austria , Humanos , Gripe Humana/mortalidad , Factores de Riesgo
13.
Strahlenther Onkol ; 175(5): 232-8, 1999 May.
Artículo en Alemán | MEDLINE | ID: mdl-10356613

RESUMEN

BACKGROUND: As known from the literature, prostate motion depends on different bladder and/or rectum fillings. The aim of this study was to analyze the influence of a rectum balloon catheter, used as an internal immobilization device, on prostate and rectum motion during the treatment course. Moreover we have analyzed if the balloon enables an increase of the distance between the prostate and the posterior rectum wall. PATIENTS AND METHODS: Ten patients with localized prostate cancer (T1 to T3) underwent computed tomographic examinations with and without rectal balloon (filled with 40 ml air) at 3 times during treatment course (at the start, middle and end of treatment). Edges of prostate, rectum and bladder were measured in relation to bony reference structures and compared for both examination series (with and without balloon). RESULTS: An increase of the distance between the prostate and the posterior rectal wall of 8 mm was observed at the base of the prostate when using the rectum balloon (Figures 1a,b and 2). Moreover prostate motion in the ventrodorsal direction > or = 4 mm (1 SD) was reduced from 6/10 patients (60%) to 1/10 patients (10%) using the rectal balloon (Table 3, Figure 3). In general, deviations in the latero-lateral and cranio-caudal directions were less (mean < or = 2 mm, 1 SD), no difference between both examination series (with and without balloon) was observed. CONCLUSION: Rectal balloon catheter offers a possibility to reduce prostate motion and rectum filling variations during treatment course. In addition it enables an increase in the distance between prostate and posterior rectal wall, which could enable an improved protection of the posterior rectal wall.


Asunto(s)
Cateterismo , Próstata/efectos de la radiación , Neoplasias de la Próstata/radioterapia , Radioterapia Conformacional , Recto/efectos de la radiación , Humanos , Inmovilización , Masculino , Peristaltismo , Próstata/fisiología , Neoplasias de la Próstata/diagnóstico por imagen , Dosificación Radioterapéutica , Planificación de la Radioterapia Asistida por Computador , Recto/fisiología , Tomografía Computarizada por Rayos X
14.
Ergonomics ; 36(11): 1345-60, 1993 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8262028

RESUMEN

In this study we investigate the behaviour and the performance of experimental subjects, who had to solve a series of tasks of 'strategic thinking' under a stress and a non-stress condition. No significant differences between the conditions could be found with respect to performance and improvement of performance within the series of tasks, but the experimental subjects exhibited under the different conditions different forms of behaviour. Unexpectedly the Ss working under the stress-condition exhibited a more 'analytical' behaviour and increased their workload, instead of decreasing it. Additionally they exhibited a tendency for measures with salient effects and proved to be better in finding the right points of main effort. The results are discussed with respect to a general theory of action regulation.


Asunto(s)
Estrés Fisiológico/psicología , Análisis y Desempeño de Tareas , Pensamiento , Humanos
15.
Z Psychol Z Angew Psychol ; 201(2): 167-202, 1993.
Artículo en Alemán | MEDLINE | ID: mdl-8101677

RESUMEN

This paper concerns the interaction of emotion and knowledge in action regulation. First a new theory of emotions is developed. Emotions are considered as modulations of cognitive processes. Such a modulation is for instance the change of the resolution level of cognitive processes. Another modulation is the change of the "updating rate" of the image of the environment. A theory is developed how these modulations are dependent on "context parameters". Action regulation is a process, which is considered as consisting of three levels. The first one is the level of the automatisms. The second level is reasoning and planning, the third level is information collection by observation or trial and error behaviour. The change between these levels is dependent on the state of the knowledge about the respective domain of reality. It can be shown, that the concept of emotion and emotional change as consisting on a context dependent change of the modulation of cognitive processes and the three stage theory of action regulation is sufficient to explain emotional forms of behaviour.


Asunto(s)
Conducta , Formación de Concepto , Emociones , Solución de Problemas , Humanos , Motivación
17.
Philos Trans R Soc Lond B Biol Sci ; 327(1241): 463-73, 1990 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-1970892

RESUMEN

Unlike other living creatures, humans can adapt to uncertainty. They can form hypotheses about situations marked by uncertainty and can anticipate their actions by planning. They can expect the unexpected and take precautions against it. In numerous experiments, we have investigated the manner in which humans deal with these demands. In these experiments, we used computer simulated scenarios representing, for example, a small town, ecological or economic systems or political systems such as a Third World country. Within these computer-simulated scenarios, the subjects had to look for information, plan actions, form hypotheses, etc.


Asunto(s)
Desastres , Lógica , Inanición , África Occidental , Animales , Humanos , Modelos Teóricos , Psicología
20.
J Vasc Surg ; 1(1): 50-6, 1984 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-6481871

RESUMEN

Nine hundred forty carotid endarterectomies were performed without the use of a temporary indwelling shunt. Six patients (0.6%) died, all from stroke; 17 other patients (1.8%) had another stroke, and 21 patients (2.2%) had temporary neurologic symptoms. Complete x-ray films detailing the opposite internal carotid artery and carotid artery back pressure were available for 783 operations. Correlation of stroke to back pressure, status of the contralateral internal carotid artery, preoperative neurologic deficit, and carotid clamp time was examined. Statistical analysis demonstrated significantly increased neurologic complications only if the systolic carotid back pressure was less than or equal to 50 mm Hg or the contralateral internal carotid artery was occluded. Analysis to determine if these factors were dependently related showed that when both a contralateral carotid occlusion and a carotid back pressure of less than or equal to 50 mm Hg coexisted (82 patients), the rate of permanent deficit was 11.0% compared with 2.8% when either factor was singly present and 0.9% when neither factor was present. No statistical difference exists between the group with only a single factor and those with neither factor. When a temporary shunt is not used during carotid endarterectomy, the risk of neurologic complication is increased if both a contralateral internal carotid artery occlusion and a carotid back pressure of less than or equal to 50 mm Hg coexist. The use of a shunt in this patient population may be beneficial.


Asunto(s)
Derivación Arteriovenosa Quirúrgica , Arterias Carótidas/cirugía , Trastornos Cerebrovasculares/cirugía , Endarterectomía/métodos , Adulto , Anciano , Enfermedades de las Arterias Carótidas/cirugía , Femenino , Humanos , Ataque Isquémico Transitorio/cirugía , Masculino , Persona de Mediana Edad
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