Salivary Bpifa1 (splunc1) And Bpifa2 (splunc2 A) Are Modified By Head And Neck Cancer Radiotherapy.

To determine the effects of radiotherapy on salivary BPIFA expression and to investigate the role of BPIFA in the development of known radiotherapy side effects. Unstimulated whole-mouth saliva was collected from 45 cancer patients (1��week before treatment, during the treatment, and 1��week after completion of radiotherapy) and from 20 controls. BPIFA1 and BPIFA2 expression was detected by western blotting and analyzed along with clinicopathologic data and side effects from the radiotherapy. A facial radiation field was associated with lower salivary flow during and after radiotherapy and correlated with side effects, mainly mucositis. Salivary BPIFA1 expression levels were similar between the control group and the patient group before treatment. On the other hand, BPIFA2 levels were higher in the patient group before treatment compared with the control group. BPIFA concentration was modified by radiotherapy as BPIFA1 levels increased (P��=��.0081) and BPIFA2 decreased (P��<��.0001). Higher levels of BPIFA1 were associated with the presence of mucositis (P��=��.0363) and its severity (P��=��.0500). The present study found that levels of BPIFA1 and glycosylated forms of BPIFA2 are affected by radiotherapy, suggesting that these proteins may play a role in the oral microenvironment in irradiated patients with head and neck cancer.

Use of active personal dosemeters in interventional radiology and cardiology: Tests in hospitals - ORAMED project

Although active personal dosemeters (APDs) are not used quite often in hospital environments, the possibility to assess the dose and/or dose rate in real time is particularly interesting in interventional radiology and cardiology (IR/IC) since operators can receive relatively high doses while standing close to the primary radiation field.A study concerning the optimization of the use of APDs in IR/IC was performed in the framework of the ORAMED project, a Collaborative Project (2008-2011) supported by the European Commission within its 7th Framework Program. This paper reports on tests performed with APDs on phantoms using an X-ray facility in a hospital environment and APDs worn by interventionalists during routine practice in different European hospitals.The behaviour of the APDs is more satisfactory in hospitals than in laboratories with respect to the influence of the tube peak high voltage and pulse width, because the APDs are tested in scattered fields with dose equivalent rates generally lower than 1 Sv.h(-1).

Extremal principle of entropy production in the climate system

Paltridge found reasonable values for the most significant climatic variables through maximizing the material transport part of entropy production by using a simple box model. Here, we analyse Paltridge's box model to obtain the energy and the entropy balance equations separately. Derived expressions for global entropy production, which is a function of the radiation field, and even its material transport component, are shown to be different from those used by Paltridge. Plausible climatic states are found at extrema of these parameters. Feasible results are also obtained by minimizing the radiation part of entropy production, in agreement with one of Planck's results, Finally, globally averaged values of the entropy flux of radiation and material entropy production are obtained for two dynamical extreme cases: an earth with uniform temperature, and an earth in radiative equilibrium at each latitudinal point

Transpalpebral proton beam radiotherapy of choroidal melanoma.

BACKGROUND: Collateral damage to upper eyelid margin during proton beam radiotherapy (PBR) for choroidal melanoma may cause squamous metaplasia of the tarsal conjunctiva with keratinisation, corneal irritation, discomfort and, rarely, corneal perforation. We evaluated transpalpebral PBR as a means of avoiding collateral damage to the upper eyelid margin without increasing the risk of failure of local tumour control. METHODS: Retrospective study of consecutive patients who underwent PBR for choroidal melanoma between 1992 and 2007 at the Royal Liverpool University Hospital and the Douglas Cyclotron at Clatterbridge Cancer Centre, UK. RESULTS: Sixty-three patients were included in this study. Mean basal tumour diameter and tumour thickness were 11.8&#8197;mm and 3.6&#8197;mm, respectively. PBR mean beam range and modulation were 26.5&#8197;mm and 16.9&#8197;mm respectively. The eyelid margin was included in the radiation field in 15 (24%) eyes. The median follow-up was 2.5&#8197;years. Local tumour recurrence developed in 2 (3.2%) patients. In these two cases that developed tumour recurrence the transpalpebral treatment did not involve the eyelid margin. Six (9.5%) patients died of metastatic disease. No eyelid or ocular surface problems developed in any of the 48 patients who were treated without eyelid rim involvement, while 7 of the 15 patients with unavoidable irradiation of the eyelid rim developed some degree of madarosis. These seven patients all received more than 26.55 proton Gy to the eyelid margin. Symptoms, such as grittiness occurred in 12% of 48 patients without eyelid margin irradiation as compared with 53% of 15 patients whose lid margin was irradiated. CONCLUSIONS: Transpalpebral PBR of choroidal melanoma avoids eyelid and ocular surface complications without increasing failure of local tumour control.

Skin cancer in survivors of childhood and adolescent cancer.

The incidence of basal cell carcinoma (BCC) has been related to ionizing radiation, particularly for exposure occurring at young age. In this study, we considered the incidence of second skin neoplasms in long-term survivors from childhood cancer. We considered second primary cancers occurring among 776 subjects (436 males, 340 females) with first primary cancer diagnosed before age 20 years, between 1974 and 2001, in the Swiss Cantons of Vaud and Neuch��tel (786,000 inhabitants). Five BCC were observed versus 0.43 expected (standardized incidence ratio: 11.6, 95% confidence interval: 3.7-27.1). No case of cutaneous squamous cell carcinoma, nor of malignant melanoma was observed. The estimated radiation doses at 1mm through the skin ranged between 7 and 27 Sv. These data confirm that BCC are strongly related to ionizing radiation exposure in childhood. All the BCC were located within the radiation field, thus indicating that ionizing radiation is the key aetiological factor, even in the absence of any meaningful interaction with UV.

Effects of convection on the removal of the multiplicity of stable states in one-dimensional vertical models

Here I develop a model of a radiative-convective atmosphere with both radiative and convective schemes highly simplified. The atmospheric absorption of radiation at selective wavelengths makes use of constant mass absorption coefficients in finite width spectral bands. The convective regime is introduced by using a prescribed lapse rate in the troposphere. The main novelty of the radiative-convective model developed here is that it is solved without using any angular approximation for the radiation field. The solution obtained in the purely radiation mode (i. e. with convection ignored) leads to multiple equilibria of stable states, being very similar to some results recently found in simple models of planetary atmospheres. However, the introduction of convective processes removes the multiple equilibria of stable states. This shows the importance of taking convective processes into account even for qualitative analyses of planetary atmosphere

The 2010 May Flaring Episode of Cygnus X-3 in Radio, X-rays, and ��-rays

In 2009, Cygnus X-3 (Cyg X-3) became the first microquasar to be detected in the GeV ��-ray regime, via the satellites Fermi and AGILE. The addition of this new band to the observational toolbox holds promise for building a more detailed understanding of the relativistic jets of this and other systems. We present a rich data set of radio, hard and soft X-ray, and ��-ray observations of Cyg X-3 made during a flaring episode in 2010 May. We detect a ~3 day softening and recovery of the X-ray emission, followed almost immediately by a ~1 Jy radio flare at 15 GHz, followed by a 4.3�� ��-ray flare (E > 100 MeV) ~1.5 days later. The radio sampling is sparse, but we use archival data to argue that it is unlikely the ��-ray flare was followed by any significant unobserved radio flares. In this case, the sequencing of the observed events is difficult to explain in a model in which the ��-ray emission is due to inverse Compton scattering of the companion star's radiation field. Our observations suggest that other mechanisms may also be responsible for ��-ray emission from Cyg X-3.

The 2010 May Flaring Episode of Cygnus X-3 in Radio, X-rays, and ��-rays

In 2009, Cygnus X-3 (Cyg X-3) became the first microquasar to be detected in the GeV ��-ray regime, via the satellites Fermi and AGILE. The addition of this new band to the observational toolbox holds promise for building a more detailed understanding of the relativistic jets of this and other systems. We present a rich data set of radio, hard and soft X-ray, and ��-ray observations of Cyg X-3 made during a flaring episode in 2010 May. We detect a ~3 day softening and recovery of the X-ray emission, followed almost immediately by a ~1 Jy radio flare at 15 GHz, followed by a 4.3�� ��-ray flare (E > 100 MeV) ~1.5 days later. The radio sampling is sparse, but we use archival data to argue that it is unlikely the ��-ray flare was followed by any significant unobserved radio flares. In this case, the sequencing of the observed events is difficult to explain in a model in which the ��-ray emission is due to inverse Compton scattering of the companion star's radiation field. Our observations suggest that other mechanisms may also be responsible for ��-ray emission from Cyg X-3.

The Possibilities and Dosimetric Limitations of MLC-Based Intensity-Modulated Radiotherapy Delivery and Optimization Techniques

The use of intensity-modulated radiotherapy (IMRT) has increased extensively in the modern radiotherapy (RT) treatments over the past two decades. Radiation dose distributions can be delivered with higher conformality with IMRT when compared to the conventional 3D-conformal radiotherapy (3D-CRT). Higher conformality and target coverage increases the probability of tumour control and decreases the normal tissue complications. The primary goal of this work is to improve and evaluate the accuracy, efficiency and delivery techniques of RT treatments by using IMRT. This study evaluated the dosimetric limitations and possibilities of IMRT in small (treatments of head-and-neck, prostate and lung cancer) and large volumes (primitive neuroectodermal tumours). The dose coverage of target volumes and the sparing of critical organs were increased with IMRT when compared to 3D-CRT. The developed split field IMRT technique was found to be safe and accurate method in craniospinal irradiations. By using IMRT in simultaneous integrated boosting of biologically defined target volumes of localized prostate cancer high doses were achievable with only small increase in the treatment complexity. Biological plan optimization increased the probability of uncomplicated control on average by 28% when compared to standard IMRT delivery. Unfortunately IMRT carries also some drawbacks. In IMRT the beam modulation is realized by splitting a large radiation field to small apertures. The smaller the beam apertures are the larger the rebuild-up and rebuild-down effects are at the tissue interfaces. The limitations to use IMRT with small apertures in the treatments of small lung tumours were investigated with dosimetric film measurements. The results confirmed that the peripheral doses of the small lung tumours were decreased as the effective field size was decreased. The studied calculation algorithms were not able to model the dose deficiency of the tumours accurately. The use of small sliding window apertures of 2 mm and 4 mm decreased the tumour peripheral dose by 6% when compared to 3D-CRT treatment plan. A direct aperture based optimization (DABO) technique was examined as a solution to decrease the treatment complexity. The DABO IMRT technique was able to achieve treatment plans equivalent with the conventional IMRT fluence based optimization techniques in the concave head-and-neck target volumes. With DABO the effective field sizes were increased and the number of MUs was reduced with a factor of two. The optimality of a treatment plan and the therapeutic ratio can be further enhanced by using dose painting based on regional radiosensitivities imaged with functional imaging methods.

Neutronis��teilylle altistuminen k��ytetyn polttoaineen siirrossa Olkiluodon voimalaitoksella

T��ss�� ty��ss�� on tutkittu OL1/OL2-ydinvoimalaitosten k��ytetyn polttoaineen siirrossa aiheutuvaa altistusta neutronis��teilylle. K��ytetty polttoaine siirret����n vedell�� t��ytetyss�� k��ytetyn polttoaineen siirtos��ili��ss�� Castor TVO:ssa OL1/OL2-laitoksilta k��ytetyn polttoaineen varastolle. Siirtoty��n aikana useat eri ammattiryhmiin kuuluvat henkil��t ty��skentelev��t siirtos��ili��n v��litt��m��ss�� l��heisyydess��, altistuen k��ytetyst�� polttoaineesta emittoituvalle fotoni- ja neutronis��teilylle. Aikaisemmista neutronis��teilyannosten mittauksista on todettu, ettei jatkuvalle altistuksen seurannalle ole ollut tarvetta. T��m��n ty��n tarkoitus on selvitt���� teoreettisilla laskelmilla siirtoty��h��n osallistuvan henkil��n mahdollisuus saada kirjausrajan ylitt��v�� annos neutronis��teily��. Neutronis��teilyn annosnopeudet siirtos��ili��t�� ymp��r��iv��ss�� tilassa on laskettu yhdysvaltalaisella Monte Carlo-menetelm����n perustuvalla MCNP-ohjelmalla. MCNP:ll�� mallinnettiin siirtos��ili��, siirtos��ili��n sis��lt��m�� polttoaine ja ymp��r��iv�� tila kolmella j����htymisajalla ja kolmella keskim����r��isell�� maksimipoistopalamalla. Polttoainenippujen isotooppikonsentraatiot ja s��teilyl��hteiden voimakkuudet on laskettu Studsvik SNF-ohjelmalla. Simuloinnin perusteella voidaan todeta, ettei neutronis��teilyannosten jatkuvalle seurannalle ole tarvetta k��ytetyn polttoaineen siirrossa. Vaikka neutronis��teilyn annosnopeudet voivat nousta siirtos��ili��n l��heisyydess�� suhteellisen suuriksi, ovat siirtos��ili��n l��hell�� teht��v��t ty��t niin lyhytaikaisia, ett�� kirjausrajan ylityst�� voidaan pit���� hyvin ep��todenn��k��isen��. Johtop����t��kset varmistetaan ty��ss�� suunnitellulla mittausj��rjestelyll��.

D��tection des ��v��nements de "Minimum Bias" et neutrons avec les d��tecteurs ATLAS-MPX par simulations

Un r��seau de seize d��tecteurs ATLAS-MPX a ��t�� mis en op��ration dans le d��tecteur ATLAS au LHC du CERN. Les d��tecteurs ATLAS-MPX sont sensibles au champ mixte de radiation de photons et d�����lectrons dans la caverne d���ATLAS et sont recouverts de convertisseurs de fluorure de lithium et de poly��thyl��ne pour augmenter l���efficacit�� de d��tection des neutrons thermiques et des neutrons rapides respectivement. Les collisions �� haute ��nergie sont domin��es par des interactions partoniques avec petit moment transverse pT , associ��s �� des ��v��nements de ���minimum bias���. Dans notre cas la collision proton-proton se produit avec une ��nergie de 7 TeV dans le centre de masse avec une luminosit�� de 10�����cm�����s����� telle que fix��e dans les simulations. On utilise la simulation des ��v��nements de "minimum bias" g��n��r��s par PYTHIA en utilisant le cadre Athena qui fait une simulation GEANT4 compl��te du d��tecteur ATLAS pour mesurer le nombre de photons, d�����lectrons, des muons qui peuvent atteindre les d��tecteurs ATLASMPX dont les positions de chaque d��tecteur sont incluses dans les algorithmes d���Athena. Nous mesurons les flux de neutrons thermiques et rapides, g��n��r��s par GCALOR, dans les r��gions de fluorure de lithium et de poly��thyl��ne respectivement. Les r��sultats des ��v��nements de ���minimum bias��� et les flux de neutrons thermiques et rapides obtenus des simulations sont compar��s aux mesures r��elles des d��tecteurs ATLAS-MPX.

A finite element-spherical harmonics model for radiative transfer in inhomogeneous clouds. Part II. some applications

EVENT has been used to examine the effects of 3D cloud structure, distribution, and inhomogeneity on the scattering of visible solar radiation and the resulting 3D radiation field. Large eddy simulation and aircraft measurements are used to create realistic cloud fields which are continuous or broken with smooth or uneven tops. The values, patterns and variance in the resulting downwelling and upwelling radiation from incident visible solar radiation at different angles are then examined and compared to measurements. The results from EVENT confirm that 3D cloud structure is important in determining the visible radiation field, and that these results are strongly influenced by the solar zenith angle. The results match those from other models using visible solar radiation, and are supported by aircraft measurements of visible radiation, providing confidence in the new model.

Global and diffuse solar irradiances in urban and rural areas in southeast Brazil

The seasonal evolution of daily and hourly values of global and diffuse solar radiation at the surface are compared for the cities of Sao Paulo and Botucatu, both located in Southeast Brazil and representative of urban and rural areas, respectively. The comparisons are based on measurements of global and diffuse solar irradiance carried out at the surface during a six year simultaneous period in these two cities. Despite the similar latitude and altitude, the seasonal evolution of daily values indicate that Sao Paulo receives, during clear sky days, 7.8% less global irradiance in August and 5.1% less in June than Botucatu. On the other hand, Sao Paulo receives, during clear sky days, 3.6% more diffuse irradiance in August and 15.6% more in June than Botucatu. The seasonal variation of the diurnal cycle confirms these differences and indicates that they are more pronounced during the afternoon. The regional differences are related to the distance from the Atlantic Ocean, systematic penetration of the sea breeze and daytime evolution of the particulate matter in Sao Paulo. An important mechanism controlling the spatial distribution of solar radiation, on a regional scale, is the sea breeze penetration in Sao Paulo, bringing moisture and maritime aerosol that in turn further increases the solar radiation scattering due to pollution and further reduces the intensity of the direct component of solar radiation at the surface. Surprisingly, under clear sky conditions the atmospheric attenuation of solar radiation in Botucatu during winter - the biomass burning period due to the sugar cane harvest - is equivalent to that at Sao Paulo City, indicating that the contamination during sugar cane harvest in Southeast Brazil has a large impact in the solar radiation field at the surface.

An automatic correction method for the heel effect in digitized mammography images

The most significant radiation field nonuniformity is the well-known Heel effect. This nonuniform beam effect has a negative influence on the results of computer-aided diagnosis of mammograms, which is frequently used for early cancer detection. This paper presents a method to correct all pixels in the mammography image according to the excess or lack on radiation to which these have been submitted as a result of the this effect. The current simulation method calculates the intensities at all points of the image plane. In the simulated image, the percentage of radiation received by all the points takes the center of the field as reference. In the digitized mammography, the percentages of the optical density of all the pixels of the analyzed image are also calculated. The Heel effect causes a Gaussian distribution around the anode-cathode axis and a logarithmic distribution parallel to this axis. Those characteristic distributions are used to determine the center of the radiation field as well as the cathode-anode axis, allowing for the automatic determination of the correlation between these two sets of data. The measurements obtained with our proposed method differs on average by 2.49 mm in the direction perpendicular to the anode-cathode axis and 2.02 mm parallel to the anode-cathode axis of commercial equipment. The method eliminates around 94% of the Heel effect in the radiological image and the objects will reflect their x-ray absorption. To evaluate this method, experimental data was taken from known objects, but could also be done with clinical and digital images.

Genesis of quantum nonlocality

We revisit the problem of an otherwise classical particle immersed in the zero-point radiation field, with the purpose of tracing the origin of the nonlocality characteristic of Schrodinger`s equation. The Fokker-Planck-type equation in the particles phase-space leads to an infinite hierarchy of equations in configuration space. In the radiationless limit the first two equations decouple from the rest. The first is the continuity equation: the second one, for the particle flux, contains a nonlocal term due to the momentum fluctuations impressed by the field. These equations are shown to lead to Schrodinger`s equation. Nonlocality (obtained here for the one-particle system) appears thus as a property of the description, not of Nature. (C) 2011 Elsevier B.V. All rights reserved.