22 research outputs found
Multicellular dosimetric chain for molecular radiotherapy exemplified with dose simulations on 3D cell spheroids
Purpose: Absorbed radiation dose-response relationships are not clear in molecular radiotherapy (MRT). Here, we propose a voxel-based dose calculation system for multicellular dosimetry in MRT. We applied confocal microscope images of a spherical cell aggregate i.e. a spheroid, to examine the computation of dose distribution within a tissue from the distribution of radiopharmaceuticals. Methods: A confocal microscope Z-stack of a human hepatocellular carcinoma HepG2 spheroid was segmented using a support-vector machine algorithm and a watershed function. Heterogeneity in activity uptake was simulated by selecting a varying amount of the cell nuclei to contain In-111, I-125, or Lu-177. Absorbed dose simulations were carried out using vxlPen, a software application based on the Monte Carlo code PENELOPE. Results: We developed a schema for radiopharmaceutical dosimetry. The schema utilizes a partially supervised segmentation method for cell-level image data together with a novel main program for voxel-based radiation dose simulations. We observed that for 177Lu, radiation cross-fire enabled full dose coverage even if the radiopharmaceutical had accumulated to only 60% of the spheroid cells. This effect was not found with 111In and 125I. Using these Auger/internal conversion electron emitters seemed to guarantee that only the cells with a high enough activity uptake will accumulate a lethal amount of dose, while neighboring cells are spared. Conclusions: We computed absorbed radiation dose distributions in a 3D-cultured cell spheroid with a novel multicellular dosimetric chain. Combined with pharmacological studies in different tissue models, our cell-level dosimetric calculation method can clarify dose-response relationships for radiopharmaceuticals used in MRT. (C) 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.Peer reviewe
Views of the Finnish Climate Panel on factors to be considered when seeting long-term emission reduction targets
Branched-chain amino acid database integrated in MEDIPAD software as a tool for nutritional investigation of mediterranean populations
Branched-chained amino acids (BCAA) are essential dietary components for humans and can act as potential biomarkers for diabetes development. To efficiently estimate dietary intake, we developed a BCAA database for 1331 food items found in the French Centre d'Information sur la Qualité des Aliments (CIQUAL) food table by compiling BCAA content from international tables, published measurements, or by food similarity as well as by calculating 267 items from Greek, Turkish, Romanian, and Moroccan mixed dishes. The database embedded in MEDIPAD software capable of registering 24 h of dietary recalls (24HDR) with clinical and genetic data was evaluated based on archived 24HDR of the Saint Pierre Institute (France) from 2957 subjects, which indicated a BCAA content up to 4.2 g/100 g of food and differences among normal weight and obese subjects across BCAA quartiles. We also evaluated the database of 119 interviews of Romanians, Turkish and Albanians in Greece (27⁻65 years) during the MEDIGENE program, which indicated mean BCAA intake of 13.84 and 12.91 g/day in males and females, respectively, comparable to other studies. The MEDIPAD is user-friendly, multilingual, and secure software and with the BCAA database is suitable for conducting nutritional assessment in the Mediterranean area with particular facilities for food administration
Enhanced performance of a silicon microfabricated direct methanol fuel cell with PtRu catalysts supported on few-walled carbon nanotubes
Vastaavana mestarina pientalohankkeessa
Tässä opinnäytetyössä käsitellään vastaavana mestarina ja pääsuunnittelijana toimimista kohteessa, joka sijaitsee Nokian Siurossa. Työn kohteena on kaksikerroksinen omakotitalo. Talon rakennustyöt aloitettiin marraskuussa 2010. Kohteen kellarikerros on harkoista muurattu ja asuinkerros on hirsirunkoinen. Asuinkerroksen ulkopuoliset rakenteet tulivat talotoimittajalta, mikä asetti tietyt vaatimukset kellarikerroksen rakentamiselle ja työn aikataulutukselle.
Opinnäytetyössä tarkastellaan Suomen lainsäädännön asettamia vaatimuksia rakennustyölle ja rakennustyöstä vastaaville osapuolille sekä tutkitaan kuinka ne ovat saavutettavissa.
Opinnäytetyön tekemisen lähtökohtana oli varmistaa rakennustyön onnistumisedellytykset, jotta tilaaja saa hyvän ja laadukkaan omakotitalon. Käytännössä tämä tarkoitti työn laadun ja työturvallisuuden varmistamista.
Opinnäytetyön onnistumista kartoitettiin tilaajalta saadun raportin avulla. Raportti pohjautuu tilaajan pitämään päiväkirjaan rakennushankkeen kulusta ja sujumisesta sekä vastaavan mestarin työn onnistumisesta. Omakotitalon rakennusprojektin ja vastaavan mestarin työn onnistumista arvioitiin myös rakennusvalvontaviranomaisten katselmuksissa.
Opinnäytetyön liitteenä olevat rakennusprojektia koskevat piirustukset ja asiakirjat jätetään julkaisematta tässä raportissa, koska ne sisältävät rakennettavan kohteen salaiseksi luokiteltuja tietoja.This thesis is about the work of a general foreman and the main designer at a house construction site in Siuro, Nokia. It is a building project of a two story private detached house with an underground basement and a ground floor for the living area.
The building was started in November 2010. The exterior structures for the living area came from the prefabricating element supplier, which set certain time limitations for the schedule of building the basement.
The thesis lists the requirements that the Finnish legislation has set on construction work and those in charge of the work at sites. It also gives a view on how to meet all the requirements.
The basis for this thesis work was to ensure successful building conditions in order to make sure the customer gets a good quality home. In practice this meant checking and verifying the quality of work and occupational safety at the site.
The succeeding of the thesis work is surveyed using a report from the customer. The report is based on the customer's diary on the progress of the construction work, the success of the general foreman and accounting on all the expenses. The success of the building project and the general foreman tasks is also evaluated in the survey reports of the building supervision authorities.
The designs and documents that make attachments to the thesis remain unpublished since they contain private information on the house under construction and the site
Nuorten mäntyjen latvuksen arkkitehtuuri: latvuskomponenttien ominaisuudet, tilajakauma ja keskinäiset suhteet.
Enhanced performance of a silicon microfabricated direct methanol fuel cell with PtRu catalysts supported on few-walled carbon nanotubes
Silicon micro fuel cells (Si-MFCs) are promising power supplies for microelectronic applications, however their development is still at early stages compared to the conventional proton exchange membrane fuel cells (PEMFCs). There are not many published reports on the durability of Si-MFCs and those available only projected the life-time of standard Vulcan based catalysts. However, the limited durability resulting from carbon corrosion is one of the crucial issues in fuel cells. In this study, Si-MFC with an integrated silicon nanograss diffusion layer is used for the direct methanol fuel cell investigations. The long-term (3-day) performance of PtRu catalysts supported on different carbon supports, namely Vulcan, Graphitized carbon nanofibers (GNFs) and Few-walled carbon nanotubes (FWCNTs), was studied. PtRu-FWCNTs and PtRu-GNFs exhibited respectively 471% (20.0 mW cm-2) and 274% (13.1 mW cm-2) power density enhancements compared to PtRu-Vulcan (3.5 mW cm-2). After 3-day durability measurements, power densitystayed at 72, 68 and 91% of the initial value, respectively for PtRu-FWCNTs, PtRu-GNFs and PtRu-Vulcan. To evaluate the influence of carbon supports as well as the distribution and the size of the nanoparticles on the overall performance of Si-MFCs, further characterizations with Raman, BET, XRD, SEM and TEM were performed.Peer reviewe