Kipsinpoiston tehostaminen alitekiertoa optimoimalla

Tiivistelmä. Tämän diplomityön tavoitteena oli selvittää, miten kipsinpoistoprosessia saataisiin tehostettua nykyisillä prosessilaitteilla Boliden Kokkola Oy:ssa. Työ rajattiin sakeuttimen alitekierron optimointiin, sillä alitteen laatu vaihtelee hyvin paljon ja se vaikuttaa merkittävästi kipsin poistumistehokkuuteen, koska alitetta hyödynnetään siemenkiteinä kipsinpoistoprosessissa. Teoriaosuudessa tarkasteltiin kipsinpoistoprosessia pintakemiallisesta näkökulmasta, sillä pintakemialliset ilmiöt määrittelevät saostuneiden kalsiumsulfaattikiteiden laadun. Työn kokeellinen osuus suoritettiin tuotantomittakaavaisilla kipsinpoiston koeajoilla, joita tehtiin kaiken kaikkiaan neljä kappaletta. Kokeiden tulokset saatiin Wedge-prosessianalytiikkaohjelmasta. Lisäksi kokeelliseen osuuteen kuului näytteiden ottamista kipsisakeuttimen alitteesta, joista määritettiin kiintoainepitoisuudet ja otettiin mikroskooppikuvat. Lisäksi alitenäytteistä määritettiin partikkelikokojakaumat ja valituista näytteistä otettiin SEM-kuvat Oulun yliopiston materiaalitutkimuskeskuksessa. Kokeellisessa osuudessa huomattiin, että prosessin hallinta voi olla hyvin haastavaa. Tämä näkyi siinä, että prosessin käyttäytymistä ei aina pystytty ennustamaan suunnitelmista huolimatta eikä merkittäviä korrelaatioita juuri löytynyt. Tulosten perusteella saatiin kuitenkin ideoitua seuraavia askelia prosessinkehitykseen.Improving the gypsum removal process by optimizing the underflow circulation. Abstract. The aim of this thesis was to study the gypsum removal process in zinc electrowinning department at Boliden Kokkola Oy and find solutions how to improve it with the existing process equipment. In addition, goals were to improve the existing process instructions on how to operate the gypsum removal process and especially improve the underflow quality, so the underflow seed circulation becomes more efficient. Research was done with trial runs in gypsum removal process. The trial runs were planned in collaboration with thesis supervisors and electrowinning department personnel. The results were obtained from Wedge process diagnostics system. An important task was to collect samples of underflow from process and analyze them in the research laboratory. I also analyzed the particle size distributions in the main laboratory and took SEM-pictures of dried underflow at the Center of Material Analysis at the University of Oulu. It was found out that controlling the gypsum removal process can be challenging because of the difficulties in repeating the experiments. There weren’t also many correlations found between process variables. However, some development ideas for future process development were made

Multiobjective optimization identifies cancer-selective combination therapies

Author summary Cancer is diagnosed in nearly 40% of people in the U.S at some point during their lifetimes. Despite decades of research to lower cancer incidence and mortality, cancer remains a leading cause of deaths worldwide. Therefore, new targeted therapies are required to further reduce the death rates and toxic effects of treatments. Here we developed a mathematical optimization framework for finding cancer-selective treatments that optimally use drugs and their combinations. The method uses multiobjective optimization to identify drug combinations that simultaneously show maximal therapeutic potential and minimal non-selectivity, to avoid severe side effects. Our systematic search approach is applicable to various cancer types and it enables optimization of combinations involving both targeted therapies as well as standard chemotherapies. Combinatorial therapies are required to treat patients with advanced cancers that have become resistant to monotherapies through rewiring of redundant pathways. Due to a massive number of potential drug combinations, there is a need for systematic approaches to identify safe and effective combinations for each patient, using cost-effective methods. Here, we developed an exact multiobjective optimization method for identifying pairwise or higher-order combinations that show maximal cancer-selectivity. The prioritization of patient-specific combinations is based on Pareto-optimization in the search space spanned by the therapeutic and nonselective effects of combinations. We demonstrate the performance of the method in the context of BRAF-V600E melanoma treatment, where the optimal solutions predicted a number of co-inhibition partners for vemurafenib, a selective BRAF-V600E inhibitor, approved for advanced melanoma. We experimentally validated many of the predictions in BRAF-V600E melanoma cell line, and the results suggest that one can improve selective inhibition of BRAF-V600E melanoma cells by combinatorial targeting of MAPK/ERK and other compensatory pathways using pairwise and third-order drug combinations. Our mechanism-agnostic optimization method is widely applicable to various cancer types, and it takes as input only measurements of a subset of pairwise drug combinations, without requiring target information or genomic profiles. Such data-driven approaches may become useful for functional precision oncology applications that go beyond the cancer genetic dependency paradigm to optimize cancer-selective combinatorial treatments.Peer reviewe

Coopetitive business models in future mobile broadband with licensed shared access (LSA)

6siopenSpectrum scarcity forces mobile network operators (MNOs) providing mobile broadband services to develop new business models that address spectrum sharing. It engages MNOs into coopetitive relationship with incumbents. Licensed Shared Access (LSA) concept complements traditional licensing and helps MNOs to access new spectrum bands on a shared basis. This paper discusses spectrum sharing with LSA from business perspective. It describes how coopetition and business model are linked conceptually, and identifies the influence of coopetition on future business models in LSA. We develop business models for dominant and challenger MNOs in traditional licensing and future with LSA. The results indicate that coopetition and business model concepts are linked via value co-creation and value co-capture. LSA offers different business opportunities to dominant and challenger MNOs. Offering, value proposition, customer segments and differentiation in business models become critical in mobile broadband.openP. Ahokangas; M. Matinmikko; I. Atkova; L.F. Minervini; S. Yrjölä; M. MustonenP., Ahokangas; M., Matinmikko; I., Atkova; Minervini, LEO FULVIO; S., Yrjölä; M., Mustone

UCHL5 expression associates with improved survival in lymph-node-positive rectal cancer

Colorectal cancer is among the three most common cancer types for both genders, with a rising global incidence. To date, prognostic evaluation is difficult and largely dependent on early detection and successful surgery. UCHL5/Uch37 is an integral part of the protein homeostasis network as one of the three deubiquitinating enzymes associated with the 26S proteasome. Here, we have investigated in colorectal cancer the possible association of UCHL5 tumor expression and patient survival. UCHL5 tumor expression was evaluated by immunohistochemistry in 779 surgically treated colorectal cancer patients from Helsinki University Hospital, Finland, with assessment of clinicopathological parameters and the effect of UCHL5 expression on patient survival. High and undetectable UCHL5 expression both correlated with increased overall disease-specific survival in the subgroup of patients with lymph-node-positive (Dukes C/stage III) rectal cancer. Within this subgroup of 105 stage-III rectal cancer patients, none of the 7 with high UCHL5 expression died of colorectal cancer within 10 years after surgery (p = 0.012). A similar, though less prominent, survival trend occurred throughout the whole patient cohort. In conclusion, UCHL5 is a promising novel prognostic marker in lymph-node-positive rectal cancer. Our results also advance the currently limited knowledge of biomarkers in colorectal cancer treatment.Peer reviewe

Enhanced Tunnelling in a Hybrid of Single-Walled Carbon Nanotubes and Graphene

Transparent and conductive films (TCFs) are of great technological importance. The high transmittance, electrical conductivity and mechanical strength make single-walled carbon nanotubes (SWCNTs) a good candidate for their raw material. Despite the ballistic transport in individual SWCNTs, however, the electrical conductivity of their networks is limited by low efficiency of charge tunneling between the tube elements. Here, we demonstrate that the nanotube network sheet resistance at high optical transmittance is decreased by more than 50% when fabricated on graphene and thus provides a comparable improvement as widely adopted gold chloride ($\mathrm{AuCl_3}$) doping. However, while Raman spectroscopy reveals substantial changes in spectral features of doped nanotubes, no similar effect is observed in presence of graphene. Instead, temperature dependent transport measurements indicate that graphene substrate reduces the tunneling barrier heights while its parallel conductivity contribution is almost negligible. Finally, we show that combining the graphene substrate and $\mathrm{AuCl_3}$ doping, the SWCNT thin films can exhibit sheet resistance as low as 36 $\Omega$/sq. at 90% transmittance.Comment: 21 pages, 6 figure

The three mouse actin-depolymerizing factor/cofilins evolved to fulfill cell-type-specific requirements for actin dynamics

Actin-depolymerizing factor (ADF)/cofilins are essential regulators of actin filament turnover. Several ADF/cofilin isoforms are found in multicellular organisms, but their biological differences have remained unclear. Herein, we show that three ADF/cofilins exist in mouse and most likely in all other mammalian species. Northern blot and in situ hybridization analyses demonstrate that cofilin-1 is expressed in most cell types of embryos and adult mice. Cofilin-2 is expressed in muscle cells and ADF is restricted to epithelia and endothelia. Although the three mouse ADF/cofilins do not show actin isoform specificity, they all depolymerize platelet actin filaments more efficiently than muscle actin. Furthermore, these ADF/cofilins are biochemically different. The epithelial-specific ADF is the most efficient in turning over actin filaments and promotes a stronger pH-dependent actin filament disassembly than the two other isoforms. The muscle-specific cofilin-2 has a weaker actin filament depolymerization activity and displays a 5-10-fold higher affinity for ATP-actin monomers than cofilin-1 and ADF. In steady-state assays, cofilin-2 also promotes filament assembly rather than disassembly. Taken together, these data suggest that the three biochemically distinct mammalian ADF/cofilin isoforms evolved to fulfill specific requirements for actin filament dynamics in different cell types