Algorithm and performance of a clinical IMRT beam-angle optimization system

This paper describes the algorithm and examines the performance of an IMRT beam-angle optimization (BAO) system. In this algorithm successive sets of beam angles are selected from a set of predefined directions using a fast simulated annealing (FSA) algorithm. An IMRT beam-profile optimization is performed on each generated set of beams. The IMRT optimization is accelerated by using a fast dose calculation method that utilizes a precomputed dose kernel. A compact kernel is constructed for each of the predefined beams prior to starting the FSA algorithm. The IMRT optimizations during the BAO are then performed using these kernels in a fast dose calculation engine. This technique allows the IMRT optimization to be performed more than two orders of magnitude faster than a similar optimization that uses a convolution dose calculation engine.Comment: Final version that appeared in Phys. Med. Biol. 48 (2003) 3191-3212. Original EPS figures have been converted to PNG files due to size limi

Large-Mass Ultra-Low Noise Germanium Detectors: Performance and Applications in Neutrino and Astroparticle Physics

A new type of radiation detector, a p-type modified electrode germanium diode, is presented. The prototype displays, for the first time, a combination of features (mass, energy threshold and background expectation) required for a measurement of coherent neutrino-nucleus scattering in a nuclear reactor experiment. The device hybridizes the mass and energy resolution of a conventional HPGe coaxial gamma spectrometer with the low electronic noise and threshold of a small x-ray semiconductor detector, also displaying an intrinsic ability to distinguish multiple from single-site particle interactions. The present performance of the prototype and possible further improvements are discussed, as well as other applications for this new type of device in neutrino and astroparticle physics (double-beta decay, neutrino magnetic moment and WIMP searches).Comment: submitted to Phys. Rev.

Glándulas de la sal en Maledictosuchus riclaensis (Metriorhynchidae, Thalattosuchia) del Calloviense de la Península Ibérica.

Maledictosuchus riclaensis es un metriorrínquido del Calloviense de la Península Ibérica. Los metriorrinquidos son un grupo de crocodilomorfos marinos que desarrollaron numerosas adaptaciones al medio marino pelágico. Además de adaptaciones morfológicas, desarrollaron glándulas de la sal hipertrofiadas, lo cual implica un alto grado de especialización. Estas glándulas se han descrito en dos especies de metriorrínquidos. Las glándulas de la sal se encargan de controlar el balance de la concentración de sales en el organismo. Al tratarse de tejidos blandos su preservación es muy poco frecuente. La tomo- grafía computarizada ha alcanzado en los últimos años gran importancia en la investigación paleontológica, ya que permite la visualización y estudio de las estructuras internas de los huesos y su digitalización en 3D, de una forma no invasiva y sin poner en riesgo al ejemplar. El holotipo de Maledictosuchus riclaensis consiste en un cráneo muy bien preservado y tres vértebras. Una tomografía computarizada del cráneo reveló la presencia de glándulas de la sal hipertrofiadas en este taxón

An overview on the natural enemies of Rhynchophorus palm weevils, with focus on R. ferrugineus.

Rhynchophorus palm weevils are large insects belonging to the family Dryophthoridae. All Rhynchophorus species are polyphagous and have a similar life history but some are major pests because of the serious economic damage they cause, in particular to several species of the family Arecaceae. Here we review the natural enemies of Rhynchophorus species in both their native and introduced regions of the world, to assess the possibility of biological control of this taxon. Moreover, particular attention is paid to the well-studied and harmful species Rhynchophorus ferrugineus, about which more information is available, and to its natural enemies in the Mediterranean region, because the impact of this pest in this recently colonized area is particularly remarkable and also the recent trend in species management is looking for indigenous natural enemies. More than 50 natural enemies have been reported to attack Rhynchophorus species, even if most of them are associated to R. ferrugineus (Olivier), highlighting the lack of information on the other species of the genus. Pros and cons of all the biological control agents are then discussed: among the considered organisms, fungi are noteworthy to be considered for inclusion in integrated pest management programs. Overall, our overview underlines the need to increase knowledge on natural enemies of all the species of the genus Rhynchophorus, to isolate more virulent strains and to determine the optimum conditions for the actions of the biocontrol agents

Advanced radiation measurement techniques in diagnostic radiology and molecular imaging.

This paper reports some technological advances recently achieved in the fields of micro-CT and small animal PET instrumentation. It highlights a balance between image-quality improvement and dose reduction. Most of the recent accomplishments in these fields are due to the use of novel imaging sensors such as CMOS-based X-ray detectors and silicon photomultipliers (SiPM). Some of the research projects carried out at the University of Pisa for the development of such advanced radiation imaging technology are also described

Successful Pregnancy and Delivery in a Patient with Chronic Myeloid Leukemia while on Dasatinib Therapy

Here we report the case of an 18-year-old woman with chronic myeloid leukemia (CML) who became pregnant while undergoing treatment with dasatinib. Before pregnancy, she received imatinib mesylate therapy but could not tolerate the treatment. The regimen was then changed to dasatinib at a dose of 70 mg b.i.d. While she was in hematological remission and on dasatinib therapy, she became pregnant. The unplanned pregnancy was identified after the patient had experienced four weeks of amenorrhea. Because the patient elected to continue the pregnancy to term, dasatinib was stopped immediately. Meanwhile, CML hematological relapse occurred and then she was treated with interferon-α (IFN-α) (9 million IU/day) throughout the pregnancy without a complete hematological response. She successfully gave birth to a male baby at 33 weeks by cesarean section delivery with no sequelae or malformations. Although this experience is limited to a single patient, it provides a useful contribution for counselling patients inadvertently exposed to dasatinib during pregnancy

The Use of Imatinib Mesylate as a Lifesaving Treatment of Chronic Myeloid Leukemia Relapse after Bone Marrow Transplantation

We describe the response of imatinib as lifesaving treatment of chronic myeloid leukemia (CML) relapse in seven patients who underwent allogeneic bone marrow transplantation (alloBMT) at our institution over a period of 4 years. Retrospective analysis of their medical records revealed that a mean age at transplant was 45.2 years. The median time to diagnosis was 7.4 years after transplant. At relapse, four, two, and one patients were classified as having hematologic, major molecular, and cytogenetic relapse, respectively. At imatinib initiation, five had CML in a chronic phase, while one patient was diagnosed as having accelerated phase and blast crisis. All these patients could be evaluated for the therapeutic efficacy. At a mean of follow-up of 1.9 years of therapy, all evaluable patients achieved major molecular response without compromising safety. Consistent with available data, our results indicate that imatinib is safe and effective treatment option for patients with relapse after BMT

Surto policlonal de infecção de corrente sanguínea causada pelo complexo Burkholderia cepacia em unidades de hospital-dia de hematologia e transplante de medula óssea

Aim: The objective was to describe an outbreak of bloodstream infections by Burkholderia cepacia complex (Bcc) in bone marrow transplant and hematology outpatients. Methods: On February 15, 2008 a Bcc outbreak was suspected. 24 cases were identified. Demographic and clinical data were evaluated. Environment and healthcare workers' (HCW) hands were cultured. Species were determined and typed. Reinforcement of hand hygiene, central venous catheter (CVC) care, infusion therapy, and maintenance of laminar flow cabinet were undertaken. 16 different HCWs had cared for the CVCs. Multi-dose heparin and saline were prepared on counter common to both units. Findings: 14 patients had B. multivorans (one patient had also B. cenopacia), six non-multivorans Bcc and one did not belong to Bcc. Clone A B. multivorans occurred in 12 patients (from Hematology); in 10 their CVC had been used on February 11/12. Environmental and HCW cultures were negative. All patients were treated with meropenem, and ceftazidime lock-therapy. Eight patients (30%) were hospitalized. No deaths occurred. After control measures (multidose vial for single patient; CVC lock with ceftazidime; cleaning of laminar flow cabinet; hand hygiene improvement; use of cabinet to store prepared medication), no new cases occurred. Conclusions: This polyclonal outbreak may be explained by a common source containing multiple species of Bcc, maybe the laminar flow cabinet common to both units. There may have been contamination by B. multivorans (clone A) of multi-dose vials.O objetivo foi descrever um surto de infecções da corrente sanguínea por complexo B. cepacia (Bcc) nos ambulatórios de hematologia e transplante de medula óssea. Métodos: Em 15/02/2008, um surto de Bcc foi suspeitado. 24 casos foram identificados. Os dados demográficos e clínicos foram avaliados. Mãos de profissionais da saúde e ambiente foram cultivadas. Espécies foram determinadas e tipadas. Reforço da higiene das mãos, cuidados com cateteres, terapia de infusão e manutenção da câmara de fluxo laminar foram realizadas. 16 profissionais de saúde (PS) diferentes manipularam os cateteres. Heparina multidoses e soro eram preparadas em um balcão comum a ambas as unidades. Resultados: 14 pacientes tiveram B. multivorans (um paciente teve também B. cenopacia), 6 Bcc não-multivorans e um teve um agente não pertencente a Bcc. Clone A de B. multivorans ocorreu em 12 pacientes (da Hematologia), em 10 o cateter havia sido utilizado nos dias 11 ou 12 de fevereiro. Culturas ambientais e de PS foram negativos. Todos os pacientes foram tratados com meropenem e selo de ceftazidima. Oito pacientes (30%) foram hospitalizados. Não ocorreram mortes. Após as medidas de controle, nenhum novo caso ocorreu. Conclusões: Este surto policlonal pode ser explicado por uma fonte comum contendo várias espécies de Bcc, talvez a câmara de fluxo laminar comum a ambas as unidades. Pode ter havido contaminação por B. multivorans (clone A) de frascos multi-dose

Two successful pregnancies in a woman with chronic myeloid leukemia exposed to nilotinib during the first trimester of her second pregnancy: case study

The occurrence of chronic myeloid leukemia in pregnancy is rare and its management poses a clinical challenge for physicians treating these patients. We report a 30-year-old woman with chronic myeloid leukemia who became pregnant twice successfully. Philadelphia-positive CML in its chronic phase was diagnosed at 16 weeks of her first gestation. At that time, she received no treatment throughout her pregnancy. At 38 weeks of gestation, a normal infant was delivered by cesarean section. At six weeks postpartum, the patient underwent imatinib mesylate therapy but she could not tolerate the treatment. The treatment was then changed to nilotinib at 400 mg orally b.i.d. Two years later, she became pregnant again while she was on nilotinib 200 mg b.i.d. The unplanned pregnancy was identified during her 7.4 weeks of gestation. Because the patient elected to continue her pregnancy, nilotinib was stopped immediately, and no further treatment was given until delivery. Neither obstetrical complications nor structural malformations in neonates in both pregnancies were observed. Both babies' growth and development have been normal. Although this experience is limited to a single patient, the success of this patient demonstrates that the management of chronic myeloid leukemia in pregnant women may be individualized based on the relative risks and benefits of the patient and fetus

Molecular features of new Peach Latent Mosaic Viroid variants suggest that recombination may have contributed to the evolution of this infectious RNA.

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