6 research outputs found

    Geochemical characterization of felsic metavolcanic rocks hosting the Archean Taivaljärvi Ag-Zn-Pb-Au deposit in the Tipasjärvi greenstone belt, eastern Finland

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    Abstract. The Taivaljärvi Ag-Zn-Pb-Au deposit is located in the Archean Tipasjärvi greenstone belt (TGB) in eastern Finland, which is part of the Tipasjärvi-Kuhmo-Suomussalmi greenstone complex. The deposit is hosted by strongly altered felsic meta-volcanic rocks and has silver as its main commodity. Geochemical characterization of the host unit of the Taivaljärvi deposit, the Koivumäki Formation, was carried out along the entire TGB. Samples of metavolcanics rocks from different profiles across the TGB were analyzed for whole-rock major and trace element chemistry, including hanging-wall, ore zone and footwall samples from the silver mine. Detailed lithogeochemical exploration techniques were applied in order to identify potential areas for new discoveries in the belt. Once fertile areas were delineated, they were contrasted with other areas of so far unproven fertility using lithogeochemical data coupled with normative mineral plots, mass-balance calculations, alteration indexes and petrographic observations. Areas of lesser and greater potential for mineralization styles similar as those of the Taivaljärvi deposit were subsequently identified. There are two main groups of felsic metavolcanic rocks. Those from the mine and the Kivisuo-Talassuo, Lapasuo and South Jäkäläsuo profiles are mainly rhyolites whereas those from the Palovaara, Katajasuo profiles and most of Koraminvaara profiles range from rhyodacites to dacites. All the rocks show a calcalkaline to transitional trend and a trace element signature of a continental arc geological setting. The main alteration processes are sericitization, chloritization and silicification. Felsic metavolcanic rocks from the mine area are of FII affinities, and show gently sloping REE patterns with La/YbN ratios of 5.5–8, moderately high Zr/Y ratios, intermediate HFSE concentrations, and negative Eu anomalies (Eu/Eu* 0.35–0.55). They indicate mass gains in K₂O, SiO₂, MgO and several metals (Ag, Pb, Zn, Au), moderate mass gains in FeO as well as depletion in Na₂O and CaO. The areas that show similar trace element signatures and mass-transfer patterns together with petrographic and geochemical evidence for alteration are Lapasuo and Kivisuo-Talassuo, followed less clearly by Koraminvaara. On the other hand, the Koivumäki, South Jäkäläsuo and Palovaara areas have different characteristics, being less favorable as exploration targets

    Tumor-derived circulating endothelial cell clusters in colorectal cancer.

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    Clusters of tumor cells are often observed in the blood of cancer patients. These structures have been described as malignant entities for more than 50 years, although their comprehensive characterization is lacking. Contrary to current consensus, we demonstrate that a discrete population of circulating cell clusters isolated from the blood of colorectal cancer patients are not cancerous but consist of tumor-derived endothelial cells. These clusters express both epithelial and mesenchymal markers, consistent with previous reports on circulating tumor cell (CTC) phenotyping. However, unlike CTCs, they do not mirror the genetic variations of matched tumors. Transcriptomic analysis of single clusters revealed that these structures exhibit an endothelial phenotype and can be traced back to the tumor endothelium. Further results show that tumor-derived endothelial clusters do not form by coagulation or by outgrowth of single circulating endothelial cells, supporting a direct release of clusters from the tumor vasculature. The isolation and enumeration of these benign clusters distinguished healthy volunteers from treatment-naïve as well as pathological early-stage (≤IIA) colorectal cancer patients with high accuracy, suggesting that tumor-derived circulating endothelial cell clusters could be used as a means of noninvasive screening for colorectal cancer. In contrast to CTCs, tumor-derived endothelial cell clusters may also provide important information about the underlying tumor vasculature at the time of diagnosis, during treatment, and throughout the course of the disease. Sci Transl Med 2016 Jun 29; 8(345):345ra8

    Unification of Treatments and Interventions for Tinnitus Patients (UNITI): a study protocol for a multi-center randomized clinical trial

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    Background Tinnitus represents a relatively common condition in the global population accompanied by various comorbidities and severe burden in many cases. Nevertheless, there is currently no general treatment or cure, presumable due to the heterogeneity of tinnitus with its wide variety of etiologies and tinnitus phenotypes. Hence, most treatment studies merely demonstrated improvement in a subgroup of tinnitus patients. The majority of studies are characterized by small sample sizes, unstandardized treatments and assessments, or applications of interventions targeting only a single organ level. Combinatory treatment approaches, potentially targeting multiple systems as well as treatment personalization, might provide remedy and enhance treatment responses. The aim of the present study is to systematically examine established tinnitus therapies both alone and in combination in a large sample of tinnitus patients. Further, it wants to provide the basis for personalized treatment approaches by evaluating a specific decision support system developed as part of an EU-funded collaborative project (Unification of treatments and interventions for tinnitus patients; UNITI project). Methods/study design This is a multi-center parallel-arm randomized clinical trial conducted at five different clinical sites over the EU. The effect of four different tinnitus therapy approaches (sound therapy, structured counseling, hearing aids, cognitive behavioral therapy) applied over a time period of 12 weeks as a single or rather a combinatory treatment in a total number of 500 chronic tinnitus patients will be investigated. Assessments and interventions are harmonized over the involved clinical sites. The primary outcome measure focuses on the domain tinnitus distress assessed via the Tinnitus Handicap Inventory. Discussion Results and conclusions from the current study might not only provide an essential contribution to combinatory and personalized treatment approaches in tinnitus but could also provide more profound insights in the heterogeneity of tinnitus, representing an important step towards a cure for tinnitus. Trial registration ClinicalTrials.gov NCT04663828. Registered on 11 December 2020

    Unification of Treatments and Interventions for Tinnitus Patients (UNITI): a study protocol for a multi-center randomized clinical trial

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    Background: Tinnitus represents a relatively common condition in the global population accompanied by various comorbidities and severe burden in many cases. Nevertheless, there is currently no general treatment or cure, presumable due to the heterogeneity of tinnitus with its wide variety of etiologies and tinnitus phenotypes. Hence, most treatment studies merely demonstrated improvement in a subgroup of tinnitus patients. The majority of studies are characterized by small sample sizes, unstandardized treatments and assessments, or applications of interventions targeting only a single organ level. Combinatory treatment approaches, potentially targeting multiple systems as well as treatment personalization, might provide remedy and enhance treatment responses. The aim of the present study is to systematically examine established tinnitus therapies both alone and in combination in a large sample of tinnitus patients. Further, it wants to provide the basis for personalized treatment approaches by evaluating a specific decision support system developed as part of an EU-funded collaborative project (Unification of treatments and interventions for tinnitus patients; UNITI project). Methods/study design: This is a multi-center parallel-arm randomized clinical trial conducted at five different clinical sites over the EU. The effect of four different tinnitus therapy approaches (sound therapy, structured counseling, hearing aids, cognitive behavioral therapy) applied over a time period of 12 weeks as a single or rather a combinatory treatment in a total number of 500 chronic tinnitus patients will be investigated. Assessments and interventions are harmonized over the involved clinical sites. The primary outcome measure focuses on the domain tinnitus distress assessed via the Tinnitus Handicap Inventory. Discussion: Results and conclusions from the current study might not only provide an essential contribution to combinatory and personalized treatment approaches in tinnitus but could also provide more profound insights in the heterogeneity of tinnitus, representing an important step towards a cure for tinnitus
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