Using low energy medical cyclotrons to produce 99mTc - Technetium

This article was retracted on 05 February 2014This paper refers to work in progress, addressing the global trouble in delivering 99mTc to Nuclear Medicine Departments, Aiming to develop an efficient, safe and economical way to directly produce Technetium 99metastable (99mTc) using lowenergy - so-called “medical” - cyclotrons. The present delivery strategy has intrinsic limitations because it is not only based on old nuclear reactors, but also limits the weekly agenda workflow. Our approach is distinct, and is based on the broad distribution network of the low energy cyclotrons and the accessibility of Molybdenum 100 (100Mo) as the target material, so the system here presented, is not based on the use of Nuclear Reactors and highly enriched (or even low enriched) Uranium 235 (235U), but entirely complying with the current international trends and directives, concerning the need to reduce the use of this potential highly critical target material. The direct production technique is based on the nuclear reaction 100Mo(p,2n)99mTc whose production yields have already been widely documented. The 99mTc is produced in a routine, reliable and efficient manner that, remaining always flexible, entirely blends with established protocols.info:eu-repo/semantics/publishedVersio

Método para revestimento de painéis de fibras de madeira de média densidade (MDF) com filmes finos de nanocelulose.

O desenvolvimento de novas tecnologias para proporcionar propriedades e características de caráter prático mais relevantes à madeira sólida e produtos à base de madeira dos materiais tem sido amplamente discutido no meio industrial e acadêmico. A proteção desses materiais contra danos físicos e mecânicos, bem como a mitigação de problemas de cunho ambiental são essenciais para prolongar a sua vida útil e ampliar o seu valor agregado no mercado. Nesse contexto, ressalta-se a importância dos painéis de fibras de madeira de média densidade (MDF) no setor florestal e madeireiro, com produção global estimada em 101 milhões de m3 no ano de 2013, segundo a FAOSTAT (2017). Apesar de os painéis MDF apresentarem excelentes características de trabalhabilidade e alta resistência biológica contra fungos, a utilização de resina ureia-formaldeído (UF) durante o seu processo de fabricação resulta em um dos desafios mais críticos enfrentados pelas indústrias do setor. Desde o processo de fabricação, bem como durante a vida útil dos painéis MDF aplicados em produtos de uso interno, há emissão de formaldeído, o qual é um gás incolor responsável por problemas ambientais e danos à saúde humana (INTERNATIONAL AGENCY FOR RESEARCH ON CANCER, 2006; De Groot et al., 2010).O desenvolvimento de novas tecnologias para proporcionar propriedades e características de caráter prático mais relevantes à madeira sólida e produtos à base de madeira dos materiais tem sido amplamente discutido no meio industrial e acadêmico. A proteção desses materiais contra danos físicos e mecânicos, bem como a mitigação de problemas de cunho ambiental são essenciais para prolongar a sua vida útil e ampliar o seu valor agregado no mercado. Nesse contexto, ressalta-se a importância dos painéis de fibras de madeira de média densidade (MDF) no setor florestal e madeireiro, com produção global estimada em 101 milhões de m3 no ano de 2013, segundo a FAOSTAT (2017). Apesar de os painéis MDF apresentarem excelentes características de trabalhabilidade e alta resistência biológica contra fungos, a utilização de resina ureia-formaldeído (UF) durante o seu processo de fabricação resulta em um dos desafios mais críticos enfrentados pelas indústrias do setor. Desde o processo de fabricação, bem como durante a vida útil dos painéis MDF aplicados em produtos de uso interno, há emissão de formaldeído, o qual é um gás incolor responsável por problemas ambientais e danos à saúde humana (INTERNATIONAL AGENCY FOR RESEARCH ON CANCER, 2006; De Groot et al., 2010).bitstream/item/218328/1/CT-460-1871-final.pd

The Threat of Capital Drain: A Rationale for Public Banks?

This paper yields a rationale for why subsidized public banks may be desirable from a regional perspective in a financially integrated economy. We present a model with credit rationing and heterogeneous regions in which public banks prevent a capital drain from poorer to richer regions by subsidizing local depositors, for example, through a public guarantee. Under some conditions, cooperative banks can perform the same function without any subsidization; however, they may be crowded out by public banks. We also discuss the impact of the political structure on the emergence of public banks in a political-economy setting and the role of interregional mobility

Should new Nuclear Reactors be considered as an option to solve Technetium shortage problem?

Worldwide, more than 80% of Nuclear Medicine procedures use a radiotracer produced through a 99Mo/99mTc generator - 99mTc – Technetium 99metastable. Most of the radiochemistry and equipments is optimized for this radioisotope characteristics already for more than 35 years, making it very difficult to replace. Worldwide production of 99Mo is based essentially with only five Nuclear Reactors that are becoming obsolete and fragile with aging, shutting down more and more frequently as they approach the end of their shelf-life. Seeking for solutions, some Governments – and the EU – plan to build new dedicated Nuclear Reactor(s). Our work defends another option

45Ti - Titanium: from cyclotron production to potential applications evaluation

Introduction: Thousands of radioisotopes are known and virtually all may be artificially produced, however clinical applications of PET imaging are mainly based on 18F, 11C, 13N and 68Ga. This trend could change in the near future, since several groups worldwide are busy developing very promising new entities aiming to contribute for spreading the use and efficacy of clinical diagnostic using Nuclear Medicine imaging techniques. Our group is developing 45Ti-Titanium, assuming it as a potential candidate, since presenting interesting properties: physical half-life of 3.09h, together with relevant chemical properties, that enable radiolabelling with bifunctional chelates, ligands or could even be useful for studies concerning the distribution of new titanium-based chemotherapy drugs or titanium oxide nanoparticles. Considering that data characterizing excitation functions is necessary for radionuclide optimal production, this work aims to disseminate results regarding the determination of excitation function of 45Sc(p,n)45Ti reaction, studied as a potential route to produce 45Ti in low energy cyclotrons

Pancreatic Transcription Factors Containing Protein Transduction Domains Drive Mouse Embryonic Stem Cells towards Endocrine Pancreas

Protein transduction domains (PTDs), such as the HIV1-TAT peptide, have been previously used to promote the uptake of proteins into a range of cell types, including stem cells. Here we generated pancreatic transcription factors containing PTD sequences and administered these to endoderm enriched mouse embryonic stem (ES) cells under conditions that were designed to mimic the pattern of expression of these factors in the developing pancreas. The ES cells were first cultured as embryoid bodies and treated with Activin A and Bone morphogenetic protein 4 (BMP4) to promote formation of definitive endoderm. Cells were subsequently plated as a monolayer and treated with different combinations of the modified recombinant transcription factors Pdx1 and MafA. The results demonstrate that each transcription factor was efficiently taken up by the cells, where they were localized in the nuclei. RT-qPCR was used to measure the expression levels of pancreatic markers. After the addition of Pdx1 alone for a period of five days, followed by the combination of Pdx1 and TAT-MafA in a second phase, up-regulation of insulin 1, insulin 2, Pdx1, Glut2, Pax4 and Nkx6.1 was observed. As assessed by immunocytochemistry, double positive insulin and Pdx1 cells were detected in the differentiated cultures. Although the pattern of pancreatic markers expression in these cultures was comparable to that of a mouse transformed β-cell line (MIN-6) and human islets, the expression levels of insulin observed in the differentiated ES cell cultures were several orders of magnitude lower. This suggests that, although PTD-TFs may prove useful in studying the role of exogenous TFs in the differentiation of ES cells towards islets and other pancreatic lineages, the amount of insulin generated is well below that required for therapeutically useful cells

TAT-Mediated Transduction of MafA Protein In Utero Results in Enhanced Pancreatic Insulin Expression and Changes in Islet Morphology

Alongside Pdx1 and Beta2/NeuroD, the transcription factor MafA has been shown to be instrumental in the maintenance of the beta cell phenotype. Indeed, a combination of MafA, Pdx1 and Ngn3 (an upstream regulator of Beta2/NeuroD) was recently reported to lead to the effective reprogramming of acinar cells into insulin-producing beta cells. These experiments set the stage for the development of new strategies to address the impairment of glycemic control in diabetic patients. However, the clinical applicability of reprogramming in this context is deemed to be poor due to the need to use viral vehicles for the delivery of the above factors. Here we describe a recombinant transducible version of the MafA protein (TAT-MafA) that penetrates across cell membranes with an efficiency of 100% and binds to the insulin promoter in vitro. When injected in utero into living mouse embryos, TAT-MafA significantly up-regulates target genes and induces enhanced insulin production as well as cytoarchitectural changes consistent with faster islet maturation. As the latest addition to our armamentarium of transducible proteins (which already includes Pdx1 and Ngn3), the purification and characterization of a functional TAT-MafA protein opens the door to prospective therapeutic uses that circumvent the use of viral delivery. To our knowledge, this is also the first report on the use of protein transduction in utero