1,377 research outputs found
Eteisvärinän rytminsiirto - milloin, kenelle ja kuinka monta kertaa?
Rytminsiirto on tärkeä akuutin eteisvärinäkohtauksen hoitomuoto. Sitä on syytä käyttää harkitusti, sillä se voi pahimmillaan olla hyödytön ja potilasturvallisuutta vaarantava toimenpide. Eteisvärinän keston varma selvittäminen on keskeinen tekijä akuutin eteisvärinäkohtauksen rytminsiirron turvallisuuden takaamiseksi. Elektiiviseen rytminsiirtoon liittyy asianmukaisen antikoagulaation aikanakin lyhytaikaisesti noin nelinkertainen aivohalvausriski verrattuna rytminsiirrosta pidättäytymiseen. Eteisvärinä uusiutuu varsin usein onnistuneenkin rytminsiirron jälkeen, ja siksi sen yhteydessä tulee aina arvioida eteisvärinän estohoidon tarve tai harkita sykkeenhallintaan siirtymistä. Sinusrytmin tavoittelu ei tuo ennustehyötyä edes nuorille eteisvärinäpotilaille.</p
Simulating atomic force microscopy imaging of the ideal and defected TiO2 (110) surface
In this study we simulate noncontact atomic force microscopy imaging of the TiO2 (110) surface using first-principles and atomistic methods. We use three different tip models to investigate the tip-surface interaction on the ideal surface, and find that agreement with experiment is found for either a silicon tip or a tip with a net positive electrostatic potential from the apex. Both predict bright contrast over the bridging oxygen rows. We then study the interaction of this tip with a bridging oxygen vacancy on the surface, and find that the much weaker interaction observed would result in vacancies appearing as dark contrast along the bright rows in images.Peer reviewe
Personality, disability-free life years, and life expectancy: Individual participant meta-analysis of 131,195 individuals from 10 cohort studies
Objective: We examined how personality traits of the Five Factor Model were related to years of healthy life years lost (mortality and disability) for individuals and the population. /
Method: Participants were 131,195 individuals from 10 cohort studies from Australia, Germany, the United Kingdom, and the United States (n = 43,935 from seven cohort studies for the longitudinal analysis of disability, assessed using scales of Activities of Daily Living). /
Results: Lower Conscientiousness was associated with higher mortality and disability risk, but only when Conscientiousness was below its median level. If the excess risk associated with low Conscientiousness had been absent, population life expectancy would have been 1.3 years longer and disability‐free life 1.0 years longer. Lower emotional stability was related to shorter life expectancy, but only among those in the lowest 15% of the distribution, and disability throughout the distribution: if the excess risk associated with low emotional stability had been absent, population life expectancy would have been 0.4 years longer and disability‐free life 2.4 years longer. /
Conclusions: Personality traits of low Conscientiousness and low emotional stability are associated with reduced healthy life expectancy of individuals and population
Efficient cartridge purification for producing high molar activity [18F]fluoro-glycoconjugates via oxime formation
Introduction 18F-fluoroglycosylation via oxime formation is a chemoselective and mild radiolabeling method for sensitive molecules. Glycosylation can also improve the bioavailability, in vivo kinetics, and stability of the compound in blood, as well as accelerate clearance of biomolecules. A typical synthesis procedure for 18F-fluoroglycosylation with [18F]FDG (2-deoxy-2-[18F]fluoro-d-glucose) and [18F]FDR (5-deoxy-5-[18F]fluoro-d-ribose) involves two HPLC (high performance liquid chromatography) purifications: one after 18F-fluorination of the carbohydrate to remove its labeling precursor, and a second one after the oxime formation step to remove the aminooxy precursor. The two HPLC purifications can be time consuming and complicate the adaptation of the synthetic strategy in nuclear medicine applications and automated synthesis. We have developed a procedure in which SPE (solid phase extraction) and resin purification methods replace both of the needed HPLC purification steps. Methods We used [18F]FDR and [18F]FDG as prosthetic groups to radiolabel two aminooxy-modified model molecules, a tetrazine and a PSMA (prostate specific membrane antigen) inhibitor. After fluorination, the excess carbohydrate precursor was removed by derivatizing it with 4,4′-dimethoxytrityl chloride (DMT-Cl). The DMT moiety increases the hydrophobicity of the unreacted precursor making the separation from the fluorinated precursor possible with simple C18 Sep-Pak cartridge. For removal of the aminooxy precursor, we used a commercially available aldehyde resin (AminoLink, Thermo Fisher Scientific). C18 Sep-Pak SPE cartridge was used to separate [18F]FDR and [18F]FDG from the 18F-fluoroglycoconjugate end product. Results [18F]FDR and [18F]FDG were efficiently purified from their precursors, free fluorine-18, and other impurities. The aldehyde resin quantitatively removed the unreacted aminooxy precursors after the oxime formation. The fluorine-18 labeled oxime end products were obtained with high radiochemical purity (>99%) and molar activity (>600 GBq μmol−1). Conclusions We have developed an efficient cartridge purification method for producing high molar activity 18F-glycoconjugates synthesized via oxime formation.Peer reviewe
Evaluation of Organo [18F]Fluorosilicon Tetrazine as a Prosthetic Group for the Synthesis of PET Radiotracers
Fluorine-18 is the most widely used positron emission tomography (PET) radionuclide currently in clinical application, due to its optimal nuclear properties. The synthesis of 18F-labeled radiotracers often requires harsh reaction conditions, limiting the use of sensitive bio- and macromolecules as precursors for direct radiolabeling with fluorine-18. We aimed to develop a milder and efficient in vitro and in vivo labeling method for trans-cyclooctene (TCO) functionalized proteins, through the bioorthogonal inverse-electron demand Diels-Alder (IEDDA) reaction with fluorine-18 radiolabeled tetrazine ([18F]SiFA-Tz). Here, we used TCO-modified bovine serum albumin (BSA) as the model protein, and isotopic exchange (IE) (19F/18F) chemistry as the labeling strategy. The radiolabeling of albumin-TCO with [18F]SiFA-Tz ([18F]6), providing [18F]fluoroalbumin ([18F]10) in high radiochemical yield (99.1 ± 0.2%, n = 3) and a molar activity (MA) of 1.1 GBq/µmol, confirmed the applicability of [18F]6 as a quick in vitro fluorination reagent for the TCO functionalized proteins. While the biological evaluation of [18F]6 demonstrated defluorination in vivo, limiting the utility for pretargeted applications, the in vivo stability of the radiotracer was dramatically improved when [18F]6 was used for the radiolabeling of albumin-TCO ([18F]10) in vitro, prior to administration. Due to the detected defluorination in vivo, structural optimization of the prosthetic group for improved stability is needed before further biological studies and application of pretargeted PET imaging
Evaluation of Organo [18F]Fluorosilicon Tetrazine as a Prosthetic Group for the Synthesis of PET Radiotracers
Fluorine-18 is the most widely used positron emission tomography (PET) radionuclide currently in clinical application, due to its optimal nuclear properties. The synthesis of 18F-labeled radiotracers often requires harsh reaction conditions, limiting the use of sensitive bio- and macromolecules as precursors for direct radiolabeling with fluorine-18. We aimed to develop a milder and efficient in vitro and in vivo labeling method for trans-cyclooctene (TCO) functionalized proteins, through the bioorthogonal inverse-electron demand Diels-Alder (IEDDA) reaction with fluorine-18 radiolabeled tetrazine ([18F]SiFA-Tz). Here, we used TCO-modified bovine serum albumin (BSA) as the model protein, and isotopic exchange (IE) (19F/18F) chemistry as the labeling strategy. The radiolabeling of albumin-TCO with [18F]SiFA-Tz ([18F]6), providing [18F]fluoroalbumin ([18F]10) in high radiochemical yield (99.1 ± 0.2%, n = 3) and a molar activity (MA) of 1.1 GBq/µmol, confirmed the applicability of [18F]6 as a quick in vitro fluorination reagent for the TCO functionalized proteins. While the biological evaluation of [18F]6 demonstrated defluorination in vivo, limiting the utility for pretargeted applications, the in vivo stability of the radiotracer was dramatically improved when [18F]6 was used for the radiolabeling of albumin-TCO ([18F]10) in vitro, prior to administration. Due to the detected defluorination in vivo, structural optimization of the prosthetic group for improved stability is needed before further biological studies and application of pretargeted PET imaging
Cycling injuries and alcohol
Background: Most of the cycling accidents that occur in Finland do not end up in the official traffic accident statistics. Thus, there is minimal information on these accidents and their consequences, particularly in cases in which alcohol was involved. The focus of the present study is on cycling accidents and injuries involving alcohol in particular. Methods: Data on patients visiting the emergency department at North Kymi Hospital because of a cycling accident was prospectively collected for two years, from June 1, 2004 to May 31, 2006. Blood alcohol concentration (BAC) was measured on admission with a breath analyser. The severity of the cycling injuries was classified according to the Abbreviated Injury Scale (AIS). Results: A total of 217 cycling accidents occurred. One third of the injured cyclists were involved with alcohol at the time of visiting the hospital. Of these, 85% were males. A blood alcohol concentration of Conclusions: Cyclists involved with alcohol were, in most cases, heavily intoxicated and were not wearing a bicycle helmet. Head injuries were more common among these cyclists than among sober cyclists. As cycling continues to increase, it is important to monitor cycling accidents, improve the accident statistics and heighten awareness of the risks of head injuries when cycling under the influence of alcohol. (c) 2018 Elsevier Ltd. All rights reserved.Peer reviewe
Prediction of bullying at work: A data-driven analysis of the Finnish public sector cohort study
AIM:
To determine the extent to which change in (i.e., start and end of) workplace bullying can be predicted by employee responses to standard workplace surveys.
METHODS:
Responses to an 87-item survey from 48,537 Finnish public sector employees at T1 (2017–2018) and T2 (2019–2020) were analyzed with least-absolute-shrinkage-and-selection-operator (LASSO) regression. The predictors were modelled both at the individual- and the work unit level. Outcomes included both the start and the end of bullying. Predictive performance was evaluated with C-indices and density plots.
RESULTS:
The model with best predictive ability predicted the start of bullying with individual-level predictors, had a C-index of 0.68 and included 25 variables, of which 6 remained in a more parsimonious model: discrimination at work unit, unreasonably high workload, threat that some work tasks will be terminated, working in a work unit where everyone did not feel they are understood and accepted, having a supervisor who was not highly trusted, and a shorter time in current position. Other models performed even worse, either from the point of view of predictive performance, or practical useability.
DISCUSSION:
While many bivariate associations between socioeconomic characteristics, work characteristics, leadership, team climate, and job satisfaction were observed, reliable individualized detection of individuals at risk of becoming bullied at workplace was not successful. The predictive performance of the developed risk scores was suboptimal, and we do not recommend their use as an individual-level risk prediction tool. However, they might be useful tool to inform decision-making when planning the contents of interventions to prevent bullying at an organizational level
Measurement of heart rate variability: a clinical tool or a research toy?
AbstractOBJECTIVESThe objectives of this review are to discuss the diversity of mechanisms that may explain the association between heart rate (HR) variability and mortality, to appraise the clinical applicability of traditional and new measures of HR variability and to propose future directions in this field of research. There is a large body of data demonstrating that abnormal HR variability measured over a 24-h period provides information on the risk of subsequent death in subjects with and without structural heart disease. However, the mechanisms responsible for this association are not completely established. Therefore, no specific therapy is currently available to improve the prognosis for patients with abnormal HR variability. Reduced HR variability has been most commonly associated with a risk of arrhythmic death, but recent data suggest that abnormal variability also predicts vascular causes of death, progression of coronary atherosclerosis and death due to heart failure. A consensus is also lacking on the best HR variability measure for clinical purposes. Time and frequency domain measures of HR variability have been most commonly used, but recent studies show that new analysis methods based on nonlinear dynamics may be more powerful in terms of risk stratification. Before the measurement of HR variability can be applied to clinical practice and used to direct therapy, more precise insight into the pathophysiological link between HR variability and mortality are needed. Further studies should also address the issue of which of the HR variability indexes, including the new nonlinear measures, is best for clinical purposes in various patient populations
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