200 research outputs found
Transient Current Technique (TCT) Characterization of Silicon Particle Detectors
Hiukkasilmaisimet altistuvat huomattavalle säteilylle tulevaisuudessa korkean energian hiukkasfysiikkakokeissa, esimerkiksi kun CERN:n hiukkaskiihdytin LHC ajanmukaistetaan. Näin ollen pii-ilmaisimien säteilynkestävyyden parantamista eli erilaisten säteilyn aiheuttamien kidevirheiden sekä ilmaisinsovellusten muokkaamista tutkitaan laajasti. Magneettisella Czochralski-menetelmällä (MCZ) valmistetuista kiekoista prosessoituja p-tyypin ilmaisimia on kuitenkin tarkasteltu melko vähän. Tässä työssä verrattiin sekä n- että p-tyypin MCZpii-ilmaisimia sekä float zone -menetelmällä (FZ) valmistetuista kiekoista prosessoituja n-tyypin ilmaisimia suorittamalla virtatransienttimittauksia (TCT).
Tulokset osoittavat, että MCZ-piin sähköiset ominaisuudet ovat huomattavasti säteilynkestävämpiä kuin FZ-piin. Tutkittujen parametrien perusteella voidaan myös päätellä, että p-tyypin MCZ-pii saattaa olla säteilynkestävämpi ilmaisinmateriaali kuin n-tyypin MCZ-pii. Tämän työn tulokset tukevat siis oletusta, että LHC-kokeiden nykyisten FZ-pii-ilmaisimien vaihtaminen n- tai p-tyypin MCZ-ilmaisimiin olisi varteenotettava vaihtoehto.In future high energy physics experiments, such as in the foreseen upgrade of the particle accelerator LHC at CERN, particle detectors will be exposed to significantly high particle radiation doses. Thus, extensive research is being conducted on improving the radiation hardness of silicon particle detectors and various defect and device engineering methods are examined. However, little data has been gathered especially from p-type magnetic Czochralski silicon (MCZ-Si) devices.
This thesis presents the results of comparative transient current technique (TCT) measurements of both n-type and p-type MCZ silicon detectors as well as n-type Float Zone (FZ) silicon detectors. The results demonstrate that the MCZ silicon devices have superior radiation hard properties in comparison with the FZ silicon devices. Various examined parameters also suggest that p-type may be a more radiation hard material solution for silicon detectors than n-type MCZ silicon. Thus, replacing the currently installed FZ silicon detectors in LHC experiments with either n-type or p-type MCZ-Si devices is a viable option
Hat der Zugang durch den Musculus pronator quadratus bei der palmaren winkelstabilen Plattenfixation distaler Radiusfrakturen Einfluss auf die Pronationskraft?
Die palmare winkelstabile Plattenosteosynthese der instabilen distalen Radiusfraktur ist zum Versorgungsstandard geworden. Kontrollierte Nachuntersuchungen mit Pronations- und Supinationskraftmessungen im postoperativen Verlauf haben bis dato kaum stattgefunden. Die Studie ging im Besonderen der Frage nach, ob und in welchem Maße sich die Pronationskraft, kurzfristig und mittelfristig, von der palmaren Plattenosteosynthese mit Inzision des Musculus pronator quadratus, beeinflusst zeigt
Cerebrospinal fluid cytokines in Lyme neuroborreliosis
Background: Lyme neuroborreliosis (LNB) is one of the manifestations of Lyme disease. Although it is known that immune reaction of LNB patients is dominated by Th1 and Th2 responses and patients have elevated numbers of B cells in their cerebrospinal fluid (CSF), not all the cells involved in inflammation and cytokine secretion have been characterized. The current diagnostics of LNB is based on intrathecal production of antibodies. In recent years, the measurement of chemokine CXCL13 concentration from the CSF has been introduced as a new promising diagnostic tool for LNB to complement the antibody-based diagnostic methods. A few other cytokines have also been analyzed as possible diagnostic markers. However, multiplex analyses simultaneously evaluating the concentrations of a large number of different cytokines in the CSF of LNB patients have been lacking thus far. Extensive cytokine profiling CSF samples of LNB patients would also help in understanding the complex immunopathogenesis of LNB.Methods: CSF samples were analyzed from 43 LNB patients, 19 controls, 18 tick-borne encephalitis patients, and 31 multiple sclerosis patients. In addition, CSF samples from 23 LNB patients obtained after the antibiotic treatment were examined. Altogether, the concentrations of 49 different cytokines were determined from all of the samples. The concentrations of 48 different cytokines were analyzed by magnetic bead suspension array using the Bio-Plex Pro Human Cytokine 21- and 27-plex panels, and the concentration of CXCL13 was analyzed by an ELISA based method.Results: Distinct cytokine profiles which were able to distinguish LNB patients from controls, tick-borne encephalitis patients, multiple sclerosis patients, and LNB patients treated with antibiotics were identified. LNB patients had elevated concentrations of all major T helper cell type cytokines (Th1, Th2, Th9, Th17, and Treg) in their CSF.Conclusions: Despite the great differences in the CSF cytokine profiles of different patient groups, CXCL13 still remained as the best marker for LNB. However, IL-1ra might also be helpful as a marker for the antibiotic treatment response. Concerning the immunopathogenesis, this is the first report suggesting the involvement of Th9 cells in the immune response of LNB
Classifying outcomes in secondary and tertiary care clinical quality registries—an organizational case study with the COMET taxonomy
The choice of what patient outcomes are included in clinical quality registries is crucial for comparable and relevant data collection. Ideally, a uniform outcome framework could be used to classify the outcomes included in registries, steer the development of outcome measurement, and ultimately enable better patient care through benchmarking and registry research. The aim of this study was to compare clinical quality registry outcomes against the COMET taxonomy to assess its suitability in the registry context.Peer reviewe
Novel Biomarkers for Diagnosing Periprosthetic Joint Infection from Synovial Fluid and Serum
Background:Synovial fluid bacterial culture is the cornerstone of confirmation or exclusion of periprosthetic joint infection (PJI). The aim of this study was to assess synovial fluid and serum biomarker patterns of patients with total joint arthroplasty (TJA), and the association of these patterns with PJI.Methods:Synovial fluid and serum samples were collected from 35 patients who were admitted to the Arthroplasty Unit of the Department of Orthopaedics and Traumatology at Turku University Hospital. Of the 25 patients who were included in the study, 10 healthy patients with an elective TJA for osteoarthritis served as the control group, and 15 patients who were admitted due to clinical suspicion of PJI with local redness, swelling, wound drainage, pain, and/or fever and who had a positive synovial fluid bacterial culture served as the study group. Logistic regression was used to assess the ability of 37 biomarkers (including cytokines, chemokines, and growth factors) with commercially available tests to detect PJIs.Results:In synovial fluid, the concentrations of sTNF-R1 and sTNF-R2 (soluble tumor necrosis factor receptors 1 and 2) and BAFF (B-cell activating factor, also known as TNFSF13B) were significantly higher in the PJI group (p Conclusions:Synovial sTNF-R2 is a promising new biomarker for detecting PJI. We are not aware of any previous reports of the use of sTNF-R2 in PJI diagnosis. More research is needed to assess the clinical importance of our findings.Level of Evidence:Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.</p
Incomplete Killing And Enhanced Activation of Islet-Reactive CD8+ T Cells by FasL-Expressing Dendritic Cells Limits Protection from Diabetes
AIMS: Autologous dendritic cells (DC) are a promising tool for induction of cytotoxic CD8+ T cell immunity against tumors and chronic viral infections. When armed with the death-inducing Fas-ligand (FasL, CD195), DC attenuate delayed-type hypersensitivity reactions and allotransplant rejection by promoting activation-induced cell death in T cells. We investigated the possibility of using FasL-expressing DC to induce deletion of islet-reactive CD8+ T cells in vivo, and to prevent destruction of pancreatic islets in a model of autoimmune diabetes. METHODS: DC, propagated from mouse bone marrow cells, were purified and made to express FasL and islet-antigen via plasmid transfection. CD8+ T cells (OT-I cells) recognizing the antigen, ovalbumin, were adoptively transferred to transgenic mice expressing ovalbumin in islets (RIP-OVAlo mice), and these mice were primed with ovalbumin. To test the potential of DC to prevent diabetes in this model, the mice were later intravenously vaccinated with the transfected DC. RESULTS: Transfected DC induced partial deletion of antigen-reactive CD8+ T cells in vivo and reduced the level of lymphocyte infiltration into pancreatic islets. Diabetes developed less frequently in vaccinated mice, but this effect was limited. Further in vitro analysis showed that FasL-expressing DC not only deleted many of the responding CD8+ T cells but also promoted the expansion of surviving cells and their IFN-? production. CONCLUSIONS: FasL-expressing DC can also have stimulatory effects on CD8+ T cells warranting further investigation into the optimal design of tolerance-promoting DC-vaccination to prevent autoimmune diabetes
Environment simulator for studying automatic crop farming
Agricultural machines capable of utilizing variable rate application technology are tackling spatial variability in agricultural fields. Agricultural field robots are the next step in technology, robots which are capable of utilizing sensor and actuating technologies without human contact and operate only areas of interest. However, agricultural field robots are still under research. Robots are just one part of the next generation of crop farming having more advanced tools to do the work which currently requires humans. The next generation of crop farming, in the vision of the authors, is based on automation, which incorporates stationary and moving sensors systems, robots, model based decision making, automated operation planning which adapts to spatial variability according to the measurements as well as to weather conditions. This article presents a top-down approach of automated crop farming using simulation, trying to cover all the component parts on a fully automated farm. In the article, the developed simulation platform is presented as well as sample simulation results. The environment simulator is based on crop growth models, weed growth models, soil models, spatial variation generation and weather statistics. Models for the environment were found in literature and were tailored and tuned to fit the simulation purposes, to form a collection of models. The collection of models was evaluated by using sensitivity analysis. Furthermore, a full scale scenario was simulated over one season, incorporating 9000 spatial cells in five fields of a farm. Keywords: robots, crop growth models, soil water models, decision making, operation plannin
The influence of dexmedetomidine and propofol on circulating cytokine levels in healthy subjects
Background:Surgery and diseases modify inflammatory responses and the immune system. Anesthetic agents also have effects on the human immune system but the responses they induce may be altered or masked by the surgical procedures or underlying illnesses. The aim of this study was to assess how single-drug dexmedetomidine and propofol anesthesia without any surgical intervention alter acute immunological biomarkers in healthy subjects.
Methods:Thirty-five healthy, young male subjects were anesthetized using increasing concentrations of dexmedetomidine (n = 18) or propofol (n = 17) until loss of responsiveness (LOR) was detected. The treatment allocation was randomized. Multi-parametric immunoassays for the detection of 48 cytokines, chemokines and growth factors were used. Concentrations were determined at baseline and at the highest drug concentration foreach subject.
Results: The changes in the concentration of eotaxin (decrease after dexmedetomidine) and platelet-derived growth factor (PDGF, increase after propofol) were statistically significantly different between the groups. Significant changes were detected within both groups; the concentrations of monocyte chemotactic protein 1, chemokine ligand 27 and macrophage migration inhibitory factor were lower in both groups after the drug administration. Dexmedetomidine decreased the concentration of eotaxin, interleukin-18, interleukin-2Rα, stem cell factor, stem cell growth factor and vascular endothelial growth factor, and propofol decreased significantly the levels of hepatocyte growth factor, IFN-γ-induced protein 10 and monokine induced by IFN-γ, and increased the levels of interleukin-17, interleukin-5, interleukin-7 and PDGF.
Conclusions:Dexmedetomidine seemed to have an immunosuppressive effect on the immune system whereas propofol seemed to induce mixed pro- and anti-inflammatory effects on the immune system. The choice of anesthetic agent could be relevant when treating patients with compromised immunological defense mechanisms. Trial registration: Before subject enrollment, the study was registered in the European Clinical Trials database(EudraCT number 2013–001496-21, The Neural Mechanisms of Anesthesia and Human Consciousness) and in ClinicalTrials.gov (Principal Investigator: Harry Scheinin, number NCT01889004, The Neural Mechanisms of Anesthesia and Human Consciousness, Part 2, on the 23rd of June 2013).</p
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