457 research outputs found

    Stabilization of Ge-rich defect complexes originating from E centers in Si1- xGex:P

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    Thermal evolution of vacancy complexes was studied in P-doped ([P]=10 exp 18 cm exp −3) proton irradiated Si1−xGex with Ge contents of 10%, 20%, and 30% in the range of 250–350 °C using positron annihilation spectroscopy. The radiation damage recovers in the course of anneals but the final state differs from that in as-grown samples indicating the presence of small Ge clusters in the samples, contrary to the initially random Ge distribution. The activation energy for the annealing process was estimated to be 1.4±0.3 eV and attributed to the dissociation energy of the vacancy-phosphorus-germanium (V-P-Ge) complex.Peer reviewe

    Multi-ancestry genome-wide association study accounting for gene-psychosocial factor interactions identifies novel loci for blood pressure traits

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    Publisher Copyright: © 2020 The Author(s)Psychological and social factors are known to influence blood pressure (BP) and risk of hypertension and associated cardiovascular diseases. To identify novel BP loci, we carried out genome-wide association meta-analyses of systolic, diastolic, pulse, and mean arterial BP, taking into account the interaction effects of genetic variants with three psychosocial factors: depressive symptoms, anxiety symptoms, and social support. Analyses were performed using a two-stage design in a sample of up to 128,894 adults from five ancestry groups. In the combined meta-analyses of stages 1 and 2, we identified 59 loci (p value < 5e−8), including nine novel BP loci. The novel associations were observed mostly with pulse pressure, with fewer observed with mean arterial pressure. Five novel loci were identified in African ancestry, and all but one showed patterns of interaction with at least one psychosocial factor. Functional annotation of the novel loci supports a major role for genes implicated in the immune response (PLCL2), synaptic function and neurotransmission (LIN7A and PFIA2), as well as genes previously implicated in neuropsychiatric or stress-related disorders (FSTL5 and CHODL). These findings underscore the importance of considering psychological and social factors in gene discovery for BP, especially in non-European populations.Peer reviewe

    Local and global behaviour of nonlinear equations with natural growth terms

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    This paper concerns a study of the pointwise behaviour of positive solutions to certain quasi-linear elliptic equations with natural growth terms, under minimal regularity assumptions on the underlying coefficients. Our primary results consist of optimal pointwise estimates for positive solutions of such equations in terms of two local Wolff's potentials.Comment: In memory of Professor Nigel Kalto

    Renal Tumor Invasion Depth and Diameter are the Two Most Accurate Anatomical Features Regarding the Choice of Radical Versus Partial Nephrectomy

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    Background and Aims: To evaluate simple tumor characteristics (renal tumor diameter and parenchymal invasion depth) compared with more complex classifications, that is, Renal Tumor Invasion Index (RTII) and Preoperative Aspects and Dimensions Used for an Anatomical classification, in predicting the type of nephrectomy (radical vs partial) performed. Material and Methods: A total of 915 patients who had undergone either partial nephrectomy (n=388, 42%) or radical nephrectomy (n=527, 58%) were identified from the Helsinki University Hospital kidney tumor database between 1 January 2006 and 31 December 2014. Tumor maximum diameter and depth of invasion into the parenchyma were estimated from computed tomography or magnetic resonance imaging images and compared with Preoperative Aspects and Dimensions Used for an Anatomical and Renal Tumor Invasion Index. Logistic regression and receiver operating curves were used to compare the parameters at predicting the type of nephrectomy. Results and conclusion: All the anatomical variables of receiver operating curve/area under the curve analyses were significant predictors for the type of nephrectomy. Parenchymal invasion (area under the curve 0.91; 95% confidence interval, 0.89-0.93), RTII (area under the curve 0.91; 95% confidence interval, 0.89-0.93), and diameter (area under the curve 0.91; 95% confidence interval, 0.89-0.93) performed significantly better than Preoperative Aspects and Dimensions Used for an Anatomical classification (area under the curve 0.88; 95% confidence interval, 0.85-0.89). In multivariable analysis, invasion depth was the best predictor of nephrectomy type (percentage correct, 85.6%). Addition of one anatomic parameter into the model of non-anatomical cofactors improved the accuracy of the model significantly, but the addition of more parameters did not. Parenchymal invasion depth and tumor diameter are the most accurate anatomical features for predicting the nephrectomy type. All potential anatomical classification systems should be tested against these two simple characteristics.Peer reviewe

    Risk of Complications After Hydrocele Surgery : A Retrospective Multicenter Study in Helsinki Metropolitan Area

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    Publisher Copyright: © 2022 The AuthorsBackground: Despite being one of the most frequent urological procedures, the risk estimates for complications after hydrocele surgery (hydrocelectomy) are uncertain. Decision-making about hydrocelectomy involves balancing the risk of complications with efficacy of surgery—a tradeoff that critically depends on the complication risks of hydrocele surgery. Objective: To examine the 90-d risks of complications of hydrocele surgery in a large, contemporary sample. Design, setting, and participants: We retrospectively reviewed all surgeries performed for nonrecurrent hydroceles conducted in all five Helsinki metropolitan area public hospitals from the beginning of 2010 till the end of 2018, and evaluated the complication outcomes. Outcome measurements and statistical analysis: The following outcomes were evaluated: (1) risk of moderate or severe (Clavien-Dindo II–V) hydrocele surgery complications, (2) risk of reoperation due to a surgical complication, and (3) risk of an unplanned postoperative visit to the emergency room or outpatient clinic, all within 90 d after surgery. Results and limitations: We identified 866 hydrocele operations (38 [4.3%] bilateral operations). A total of 139 (16.1%) patients had moderate or severe hydrocele surgery complications within 90 d after surgery. Of the 139 complications, 94 were (10.9% of all or 67.6% of patients with moderate or severe complications) Clavien-Dindo grade II, 43 (5.0% and 30.9%, respectively) grade III, two (0.2% and 1.4%, respectively) grade IV, and none grade V. A total of 45 patients (5.2% of all and 32.4% of those who had moderate or severe complications) required immediate reoperation due to complications. All together 219 operated patients (25.3% of all operated patients) had an unplanned visit to the emergency room. The retrospective study design limits the reliability of the results. Conclusions: Complications after hydrocele surgery are common and warrant further research. These estimates can be useful in shared decision-making between clinicians and patients. Patient summary: We investigated the complication rates after hydrocele surgery and found that complications are common after a procedure often considered minor: every ninth patient had a moderate and every 20th a severe complication. Every fourth patient had an unplanned postoperative visit to the emergency room.Peer reviewe

    Si nanoparticle interfaces in Si/SiO2 solar cell materials

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    Novel solar cell materials consisting of Si nanoparticles embedded in SiO2 layers have been studied using positron annihilation spectroscopy in Doppler broadening mode and photoluminescence. Two positron-trapping interface states are observed after high temperature annealing at 1100 °C. One of the states is attributed to the (SiO2/Si bulk) interface and the other to the interface between the Si nanoparticles and SiO2. A small reduction in positron trapping into these states is observed after annealing the samples in N2 atmosphere with 5% H2. Enhanced photoluminescence is also observed from the samples following this annealing step.Peer reviewe

    Removal of proteinase K resistant alpha Syn species does not correlate with cell survival in a virus vector-based Parkinson's disease mouse model

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    Parkinson's disease (PD) is characterized by degeneration of nigrostriatal dopaminergic neurons and accumu-lation of alpha-synuclein (alpha Syn) as Lewy bodies. Currently, there is no disease-modifying therapy available for PD. We have shown that a small molecular inhibitor for prolyl oligopeptidase (PREP), KYP-2047, relieves alpha Syn-induced toxicity in various PD models by inducing autophagy and preventing alpha Syn aggregation. In this study, we wanted to study the effects of PREP inhibition on different alpha Syn species by using cell culture and in vivo models.We used Neuro2A cells with transient alpha Syn overexpression and oxidative stress or proteasomal inhibition -induced alpha Syn aggregation to assess the effect of KYP-2047 on soluble alpha Syn oligomers and on cell viability. Here, the levels of soluble alpha Syn were measured by using ELISA, and the impact of KYP-2047 was compared to anle138b, nilotinib and deferiprone. To evaluate the effect of KYP-2047 on alpha Syn fibrillization in vivo, we used unilateral nigral AAV1/2-A53T-alpha Syn mouse model, where the KYP-2047 treatment was initiated two-or four -weeks post injection.KYP-2047 and anle138b protected cells from alpha Syn toxicity but interestingly, KYP-2047 did not reduce soluble alpha Syn oligomers. In AAV-A53T-alpha Syn mouse model, KYP-2047 reduced significantly proteinase K-resistant alpha Syn oligomers and oxidative damage related to alpha Syn aggregation. However, the KYP-2047 treatment that was initiated at the time of symptom onset, failed to protect the nigrostriatal dopaminergic neurons. Our results emphasize the importance of whole alpha Syn aggregation process in the pathology of PD and raise an important question about the forms of alpha Syn that are reasonable targets for PD drug therapy.Peer reviewe

    Full-wave invisibility of active devices at all frequencies

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    There has recently been considerable interest in the possibility, both theoretical and practical, of invisibility (or "cloaking") from observation by electromagnetic (EM) waves. Here, we prove invisibility, with respect to solutions of the Helmholtz and Maxwell's equations, for several constructions of cloaking devices. Previous results have either been on the level of ray tracing [Le,PSS] or at zero frequency [GLU2,GLU3], but recent numerical [CPSSP] and experimental [SMJCPSS] work has provided evidence for invisibility at frequency k≠0k\ne 0. We give two basic constructions for cloaking a region DD contained in a domain Ω\Omega from measurements of Cauchy data of waves at \p \Omega; we pay particular attention to cloaking not just a passive object, but an active device within DD, interpreted as a collection of sources and sinks or an internal current.Comment: Final revision; to appear in Commun. in Math. Physic

    Recycling of Superbase-Based Ionic Liquid Solvents for the Production of Textile-Grade Regenerated Cellulose Fibers in the Lyocell Process

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    This article has a correction concerning the authors: We regret that there is an error with the author list in our original article. The authors Jussi Helminen, Paulus HyvÀri, and Ilkka KilpelÀinen, all with the Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 Helsinki, Finland, were mistakenly omitted. The author list should be as shown above in this Addition and Correction. DOI 10.1021/acssuschemeng.0c07773Ioncell is a Lyocell based technology for the production of manmade cellulose fibers. This technology exploits the intrinsic dissolution power of superbase-based ionic liquids (ILs) toward cellulose and the ability to form spinnable cellulose solutions. The regenerated fibers are produced via a dry-jet wet spinning process in which the cellulose filaments are stretched in an air gap before regenerating in an aqueous coagulation medium. For the commercialization of this process, it is essential to demonstrate the quantitative recovery of the solvent from the coagulation bath without impairing its solvation power. This study reports on the spinnability and recyclability of the IL 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-enium acetate ([mTBDH][OAc]) over five cycles in comparison to 1,5-diaza-bicyclo[4.3.0]non-5-enium acetate ([DBNH][OAc]). The aqueous IL solutions were recovered from the coagulation bath by successive thermal treatments under reduced pressure. Accordingly, the recycled ILs were utilized to dissolve 13 wt % cellulose pulp in each cycle without the addition of make-up IL. While using [mTBDH][OAc], the pulp was completely dissolved and processed into easily spinnable cellulose solutions during all five cycles, whereas the ability to dissolve pulp was completely lost after the first recovery cycle when using [DBNH][OAc]. The composition of the recovered ILs and extent of side-products generated in the adopted process was analyzed in detail. This includes characterization of the rheological properties of the solutions as well as the macromolecular and mechanical properties of the regenerated fibers. In addition, we review the toxicity of both solvents using Vibrio fischeri bacteria. Finally, the spun fibers from all [mTBDH][OAc] spinning trials were combined to produce a demonstration dress (Paju), designed and sewn by Marimekko Design House in Finland.Peer reviewe

    An overview of the European health examination survey pilot joint action

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    Background Health Examination Surveys (HESs) can provide essential information on the health and health determinants of a population, which is not available from other data sources. Nevertheless, only some European countries have systems of national HESs. A study conducted in 2006-2008 concluded that it is feasible to organize national HESs using standardized measurement procedures in nearly all EU countries. The feasibility study also outlined a structure for a European Health Examination Survey (EHES), which is a collaboration to organize standardized HESs in countries across Europe. To facilitate setting up national surveys and to gain experience in applying the EHES methods in different cultures, EHES Joint Action (2010-2011) planned and piloted standardized HESs in the working age population in 12 countries. This included countries with earlier national HESs and countries which were planning their first national HES. The core measurements included in all surveys were weight, height, waist circumference and blood pressure, and blood samples were taken to measure lipid profiles and glucose or glycated haemoglobin (HbA1c). These are modifiable determinants of major chronic diseases not identified in health interview surveys. There was a questionnaire to complement the data on the examination measurements. Methods Evaluation of the pilot surveys was based on review of national manuals and evaluation reports of survey organizers; observations and discussions of survey procedures during site visits and training seminars; and other communication with the survey organizers. Results Despite unavoidable differences in the ways HESs are organized in the various countries, high quality and comparability of the data seems achievable. The biggest challenge in each country was obtaining high participation rate. Most of the pilot countries are now ready to start their full-size national HES, and six of them have already started. Conclusions The EHES Pilot Project has set up the structure for obtaining comparable high quality health indicators on health and important modifiable risk factors of major non-communicable diseases from the European countries. The European Union is now in a key position to make this structure sustainable. The EHES core survey can be expanded to cover other measurements
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