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PURPOSE. To determine whether in vivo confocal microscopy (IVCM) of the cornea can be used for the label-free detection and monitoring of lymph vessels in live corneas. METHODS. Parallel corneal hemangiogenesis and lymphangiogenesis was induced by the placement of a single suture in one cornea of male Wistar rats. Fourteen days after suture placement and under general anesthesia, laser-scanning IVCM was performed in the vascularized region. Corneas were subsequently excised for flat-mount double immunofluorescence with a pan-endothelial marker (PECAM-1/CD31) and a lymphatic endothelial specific marker (LYVE-1). Using the suture area and prominent blood vessels as points of reference, the identical microscopic region was located in both fluorescent and archived in vivo images. Additionally, vessel diameter, lumen contrast, and cell diameter and velocity within vessels were quantified from in vivo images. RESULTS. Comparison of identical corneal regions in fluorescence and in vivo revealed prominent CD31(+)/LYVE-1(3+) lymph vessels that were visible in vivo. In vivo, corneal lymph vessels were located in the vascularized area in the same focal plane as blood vessels but had a darker lumen (P andlt; 0.001) sparsely populated by highly reflective cells with diameters similar to those of leukocytes in blood vessels (P = 0.61). Cell velocity in lymph vessels was significantly reduced compared with blood particle velocity (P andlt; 0.001). Morphologic characteristics enabled subsequent identification of corneal lymphatics in live, vascularized rat corneas before immunofluorescence labeling. CONCLUSIONS. IVCM enabled the nondestructive, label-free, in vivo detection of corneal lymphatics. IVCM provides the possibility of observing lymphatic activity in the same live corneas longitudinally and, as a clinical instrument, of monitoring corneal lymphatics in live human subjects

Universal field matching in craniospinal irradiation by a background-dose gradient-optimized method

Purpose: The gradient-optimized methods are overcoming the traditional feathering methods to plan field junctions in craniospinal irradiation. In this note, a new gradient-optimized technique, based on the use of a background dose, is described. Methods: Treatment planning was performed by RayStation (RaySearch Laboratories, Stockholm, Sweden) on the CT scans of a pediatric patient. Both proton (by pencil beam scanning) and photon (by volumetric modulated arc therapy) treatments were planned with three isocenters. An 'in silico' ideal background dose was created first to cover the upper-spinal target and to produce a perfect dose gradient along the upper and lower junction regions. Using it as background, the cranial and the lower-spinal beams were planned by inverse optimization to obtain dose coverage of their relevant targets and of the junction volumes. Finally, the upper-spinal beam was inversely planned after removal of the background dose and with the previously optimized beams switched on. Results: In both proton and photon plans, the optimized cranial and the lower-spinal beams produced a perfect linear gradient in the junction regions, complementary to that produced by the optimized upper-spinal beam. The final dose distributions showed a homogeneous coverage of the targets. Discussion: Our simple technique allowed to obtain high-quality gradients in the junction region. Such technique universally works for photons as well as protons and could be applicable to the TPSs that allow to manage a background dose

A filtering approach for PET and PG predictions in a proton treatment planning system

Positron emission tomography (PET) and prompt gamma (PG) detection are promising proton therapy monitoring modalities. Fast calculation of the expected distributions is desirable for comparison to measurements and to develop/train algorithms for automatic treatment error detection. A filtering formalism was used for positron-emitter predictions and adapted to allow for its use for the beamline of any proton therapy centre. A novel approach based on a filtering formalism was developed for the prediction of energy-resolved PG distributions for arbitrary tissues. The method estimates PG yields and their energy spectra in the entire treatment field. Both approaches were implemented in a research version of the RayStation treatment planning system. The method was validated against PET monitoring data and Monte Carlo simulations for four patients treated with scanned proton beams. Longitudinal shifts between profiles from analytical and Monte Carlo calculations were within -1.7 and 0.9 mm, with maximum standard deviation of 0.9 mm and 1.1 mm, for positron-emitters and PG shifts, respectively. Normalized mean absolute errors were within 1.2 and 5.3%. When comparing measured and predicted PET data, the same more complex case yielded an average shift of 3 mm, while all other cases were below absolute average shifts of 1.1 mm. Normalized mean absolute errors were below 7.2% for all cases. A novel solution to predict positron-emitter and PG distributions in a treatment planning system is proposed, enabling calculation times of only a few seconds to minutes for entire patient cases, which is suitable for integration in daily clinical routine

Production of e+e- pairs in proton-deuteron capture to 3He

The process p+d \leftrightarrow 3He + \gamma* at intermediate energies is described using a covariant and gauge-invariant model, and a realistic pd3He vertex. Both photodisintegration of 3He and proton-deuteron capture with production of e+e- pairs are studied, and results for cross sections and response functions are presented. The effect of time-like formfactors on the dilepton cross sections is investigated as well.Comment: 10 pages, 4 figures, Revtex, to be published in Physics Letters

Kommuners krav på bostadsbyggande : En studie om förekomsten av särkrav

Sedan en tid tillbaka har det uppmärksammats att flera svenska kommuner ställer högre krav på byggnadsverks tekniska egenskaper än Boverket när de tecknar markanvisningsavtal, det vill säga, genomförandeavtal för markexploatering av kommunalägd mark. Detta torde i princip vara tillåtet då kommunerna i dessa fall agerar som markägare och inte som myndighet, men däremot är det inte möjligt att ställa sådana krav vid exploatering av privatägd mark enligt nuvarande lagstiftning. Trots detta har det framkommit många påståenden om att sådana krav, så kallade särkrav, likväl förekommer och att dessa orsakar stora merkostnader för byggherrar. Huruvida detta stämmer har dock inte kontrollerats och det har fram tills nu inte funnits någon tydlig bild av vilka krav olika kommuner egentligen ställer. Denna uppsats är avsedd att undersöka den faktiska förekomsten av särkrav i bostadsprojekt genom att granska de exploateringsavtal och planhandlingar m.m. som tagits fram de senaste åren av 15 av de kommuner i Sverige där det har byggts mest under denna tid. Vidare beskriver också uppsatsen den lagstiftning som reglerar kravställande på byggande och redogör för några av de eventuella konsekvenser som tillämpning av särkrav kan ge upphov till. Förhoppningsvis kommer detta ge en tydligare bild av kommunernas kravställande samt ge underlag inför framtida studier om hur särkrav bör hanteras