Publications by authors named "Rajala P"

Membrane external-cavity surface-emitting lasers (MECSELs) represent a cutting-edge approach in pushing the performance boundaries of vertically emitting semiconductor lasers. The fundamental concept of employing an extremely thin gain membrane, spanning from hundreds of nanometers to a few micrometers in thickness and sandwiched between transparent heat spreaders, introduces novel opportunities through uniform double-sided optical pumping and enhanced heat dissipation from the active region. Additionally, these advantages of MECSELs facilitate more intricate band gap engineering possibilities for the active region by integrating multiple types of quantum wells (QWs) into a single laser gain structure.

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Background: Arterial lactate measurements were recently suggested as an early predictor of clinically relevant post-hepatectomy liver failure (PHLF). This needed to be evaluated in the subgroup of major hepatectomies only.

Method: This observational cohort study included consecutive elective major hepatectomies at Karolinska University Hospital from 2010 to 2018.

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Low and intermediate level radioactive waste produced during the operation and decommissioning of nuclear power plants is disposed of in an underground geological repository. The majority of metallic waste is made of various stainless-steels and carbon steel. Microbial communities and groundwater composition in deep bedrock at repository sites were believed to stay stable over time, allowing the prediction of evolution of the repository environment.

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Background: Metal corrosion in seawater has been extensively studied in surface and shallow waters. However, infrastructure is increasingly being installed in deep-sea environments, where extremes of temperature, salinity, and high hydrostatic pressure increase the costs and logistical challenges associated with monitoring corrosion. Moreover, there is currently only a rudimentary understanding of the role of microbially induced corrosion, which has rarely been studied in the deep-sea.

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Fungi have an important role in nutrient cycling in most ecosystems on Earth, yet their ecology and functionality in deep continental subsurface remain unknown. Here, we report the first observations of active fungal colonization of mica schist in the deep continental biosphere and the ability of deep subsurface fungi to attach to rock surfaces under in situ conditions in groundwater at 500 and 967 m depth in Precambrian bedrock. We present an in situ subsurface biofilm trap, designed to reveal sessile microbial communities on rock surface in deep continental groundwater, using Outokumpu Deep Drill Hole, in eastern Finland, as a test site.

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We studied and compared single-side pumping (SSP) and double-side pumping (DSP) of a semiconductor membrane external-cavity surface-emitting laser (MECSEL). The MECSEL-active region was based on an AlGaAs quantum well structure embedded between two silicon carbide (SiC) wafer pieces that were used as transparent intra-cavity (IC) heat spreaders creating a symmetrical cooling environment. The gain structure targeted emission at 780 nm, a wavelength region that is important for many applications, and where the development of high-brightness high-power laser sources is gaining more momentum.

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In this work, six common stainless steel grades were compared with respect to ennoblement characteristics, corrosion performance and tendency to biofouling in brackish sea water in a pilot-scale cooling water circuit. Two tests were performed, each employing three test materials, until differences between the materials were detected. Open circuit potential (OCP) was measured continuously in situ.

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Microbial communities in deep subsurface environments comprise a large portion of Earth's biomass, but the metabolic activities in these habitats are largely unknown. Here the effect of CO and carbonate on the microbial community of an isolated groundwater fracture zone at 180 m depth of the Outokumpu Deep Scientific Drill Hole (Finland) was tested. Outokumpu groundwater at 180 m depth contains approximately 0.

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Microbial communities in deep subsurface environments comprise a large portion of Earth's biomass, but the microbial activity in these habitats is largely unknown. Here, we studied how microorganisms from two isolated groundwater fractures at 180 and 500 m depths of the Outokumpu Deep Drillhole (Finland) responded to methane or methanol amendment, in the presence or absence of sulfate as an additional electron acceptor. Methane is a plausible intermediate in the deep subsurface carbon cycle, and electron acceptors such as sulfate are critical components for oxidation processes.

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Understanding the corrosion of carbon steel materials of low and intermediate level radioactive waste under repository conditions is crucial to ensure the safe storage of radioactive contaminated materials. The waste will be in contact with the concrete of repository silos and storage containers, and eventually with groundwater. In this study, the corrosion of carbon steel under repository conditions as well as the microbial community forming biofilm on the carbon steel samples, consisting of bacteria, archaea, and fungi, was studied over a period of three years in a groundwater environment with and without inserted concrete.

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Cooling systems remove heat from components and industrial equipment. Water cooling, employing natural waters, is typically used for cooling large industrial facilities, such as power plants, factories or refineries. Due to moderate temperatures, cooling water cycles are susceptible to biofouling, inorganic fouling and scaling, which may reduce heat transfer and enhance corrosion.

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We investigated the N-utilizing bacterial community in anoxic brackish groundwater of the low and intermediate level nuclear waste repository cave in Olkiluoto, Finland, at 100 m depth using (15)N-based stable isotope probing (SIP) and enrichment with (14∕15)N-ammonium or (14∕15)N-nitrate complemented with methane. Twenty-eight days of incubation at 12°C increased the concentration of bacterial 16S rRNA and nitrate reductase (narG) gene copies in the substrate amended microcosms simultaneously with a radical drop in the overall bacterial diversity and OTU richness. Hydrogenophaga/Malikia were enriched in all substrate amended microcosms and Methylobacter in the ammonium and ammonium+methane supplemented microcosms.

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The metallic low and intermediate level radioactive waste generally consists of carbon steel and stainless steels. The corrosion rate of carbon steel in deep groundwater is typically low, unless the water is very acidic or microbial activity in the environment is high. Therefore, the assessment of microbially induced corrosion of carbon steel in deep bedrock environment has become important for evaluating the safety of disposal of radioactive waste.

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Microorganisms in the deep biosphere are believed to conduct little metabolic activity due to low nutrient availability in these environments. However, destructive penetration to long-isolated bedrock environments during construction of underground waste repositories can lead to increased nutrient availability and potentially affect the long-term stability of the repository systems, Here, we studied how microorganisms present in fracture fluid from a depth of 500 m in Outokumpu, Finland, respond to simple carbon compounds (C-1 compounds) in the presence or absence of sulphate as an electron acceptor. C-1 compounds such as methane and methanol are important intermediates in the deep subsurface carbon cycle, and electron acceptors such as sulphate are critical components of oxidation processes.

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Purpose: We evaluated the long-term efficacy of a single dose of interferon or epirubicin administered immediately after transurethral resection compared with transurethral resection alone for primary superficial bladder cancer recurrence.

Material And Methods: A total of 200 patients with primary superficial stages Ta to T1, grades 1 to 3 bladder cancer were randomized into 3 treatment groups, including transurethral resection alone, transurethral resection plus 50 milliunits interferon-alpha2b and transurethral resection plus 100 mg. epirubicin.

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Objectives: The objective of the study is to evaluate the agreement of local and review urinary cytology in patients with newly diagnosed bladder cancer and in those being followed for their disease. In addition, the effect of the type of institution on agreement was determined.

Methods: A total of 652 consecutive patients with bladder cancer from 19 institutions were evaluated; 575 (88.

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Objectives: To study the factors determining new recurrences in patients with frequently recurring superficial bladder tumors.

Methods: Of all 205 eligible patients, each received 5 weekly intravesical instillations of mitomycin C (MMC), with the first instillation given perioperatively. This was followed, according to randomization, by BCG instillations alone or by alternating instillations of interferon-alpha and BCG monthly for up to 1 year.

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We report a case of rare benign bladder leiomyoma. The patient was a 42-year old man complaining impotence. Digital rectal examination revealed a palpable pelvic tumor.

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We report a case of rare benign bladder leiomyoma. The patient was a 42-year old man complaining impotence. Digital rectal examination revealed a palpable pelvic tumor.

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The enzymes cyclooxygenase-1 (Cox-1) and cyclooxygenase-2 (Cox-2) catalyze the initial step in the formation of prostaglandins (PGs). PGs are known to be involved in numerous processes, for example inflammation, immune responses, carcinogenesis, and tumor angiogenesis. The formation of PGs is stimulated in various cancers since the expression of Cox-2 is upregulated.

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Objective: This study investigated the outcome of testicular cancer treatment in Finland.

Material And Methods: Data on 88 testicular cancer patients treated in Turku University Central Hospital between 1976 and 1992 were studied to analyse outcome and survival.

Results: The histological diagnosis was seminoma for 39 patients and non-seminoma for 49 patients.

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Immunoreactivity of p21WAF1/CIP1 and cyclin D1 proteins was assessed in a cohort of 207 patients with superficial (pTa-pT1) bladder cancer followed up for a mean of 4.9 years. The results of the immunostainings were compared with T category, WHO grade, tumor cell proliferation rate (MIB-1 score), the expressions of p53 and bcl-2 as well as survival.

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Objective: A prospective randomized study was undertaken to determine whether cell proliferation indices (M/V index, MIB1), papillary status, the expression of p53 and epidermal growth factor receptor (EGFr) have prognostic value in superficial (pTa-pT1) bladder cancer (SBC).

Methods: 207 patients with primary SBC were followed up over a period of 4.9 (range 3.

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