| 3011. |
- Steinacker, Petra, et al.
(author)
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Neurofilaments in the diagnosis of motoneuron diseases : a prospective study on 455 patients
- 2016
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In: Journal of Neurology, Neurosurgery and Psychiatry. - : BMJ. - 0022-3050 .- 1468-330X. ; 87:1, s. 12-20
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Journal article (peer-reviewed)abstract
- Objectives Biomarkers for the diagnosis of motoneuron diseases (MND) are urgently needed to improve the diagnostic pathway, patient stratification and monitoring. The aim of this study was to validate candidate markers for MND in cerebrospinal fluid (CSF) and specify cut-offs based on large patient cohorts by especially considering patients who were seen under the initial differential diagnosis (MND mimics). Methods In a prospective study, we investigated CSF of 455 patients for neurofilament light chain (NfL), phosphorylated heavy chain (pNfH), tau protein (Tau) and phospho-tau protein (pTau). Analysed cohorts included patients with apparently sporadic and familial amyotrophic lateral sclerosis (ALS) and primary lateral sclerosis (PLS) (MND, n=253), MND mimics (n=85) and neurological control groups. Cut-off values were specified, and diagnostic performance and correlation with progression were analysed. Results Nfs were significantly higher in the MND group compared to the control groups, whereas Tau and pTau did not differ. At a cut-off level of 2200 pg/mL for NfL, a 77% diagnostic sensitivity (CI 71% to 82%), 85% specificity (CI 79% to 90%) and 87% positive predictive value (PPV) (CI 81% to 91%) were achieved. For pNfH, we calculated 83% sensitivity (CI 78% to 88%), 77% specificity (CI 71% to 83%) and 82% PPV (CI 77% to 86%) at 560 pg/mL. There were no significant differences between sporadic and genetic ALS or PLS. Nf levels were elevated at early disease stage, and correlated moderately with MND progression and duration. Conclusions Neurofilaments in CSF have a high relevance for the differential diagnosis of MNDs and should be included in the diagnostic work-up of patients. Their value as prognostic markers should be investigated further.
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| 3012. |
- Steinleitner, Philipp, et al.
(author)
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Dielectric Engineering of Electronic Correlations in a van der Waals Heterostructure
- 2018
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In: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 18:2, s. 1402-1409
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Journal article (peer-reviewed)abstract
- Heterostructures of van der Waals bonded layered materials offer unique means to tailor dielectric screening with atomic-layer precision, opening a fertile field of fundamental research. The optical analyses used so far have relied on interband spectroscopy. Here we demonstrate how a capping layer of hexagonal boron nitride (hBN) renormalizes the internal structure of excitons in a WSe 2 monolayer using intraband transitions. Ultrabroadband terahertz probes sensitively map out the full complex-valued mid-infrared conductivity of the heterostructure after optical injection of 1s A excitons. This approach allows us to trace the energies and line widths of the atom-like 1s-2p transition of optically bright and dark excitons as well as the densities of these quasiparticles. The excitonic resonance red shifts and narrows in the WSe 2 /hBN heterostructure compared to the bare monolayer. Furthermore, the ultrafast temporal evolution of the mid-infrared response function evidences the formation of optically dark excitons from an initial bright population. Our results provide key insight into the effect of nonlocal screening on electron-hole correlations and open new possibilities of dielectric engineering of van der Waals heterostructures.
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| 3013. |
- Stepanova, K. V., et al.
(author)
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Influence of annealing on the structure of nanoporous oxide films on the surface of titanium‒aluminum powder alloy
- 2016
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In: Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques. - Moscow : Maik Nauka/Interperiodica. - 1027-4510. ; 10:5, s. 933-941
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Journal article (peer-reviewed)abstract
- Oxide films obtained during anodization of Ti‒40% Al sintered powder samples in fluorine-containing electrolytes are investigated. With scanning electron microscopy and X-ray phase analysis, it is demonstrated that an X-ray amorphous nanoporous anodic oxide film is formed on the surface of the powder microparticles under optimal anodization conditions. After annealing at T = 1093 K in air and vacuum (10‒2 Pa), the oxide films are revealed to crystallize with its regular porous structure retained. The composition of the polycrystalline anodic-oxide films annealed in air is a mixture involving TiO2 (anatase and rutile) and α- and γ-Al2O3 phases and Ti2O3 and Al2TiO5 traces. The vacuum annealing process makes it possible to identify TiO2, in which anatase is the main phase, α- and γ-Al2O3, and Ti2O3 and TiO traces. However, rutile is not revealed. The presented results indicate that the application of the anodic nanostructuring of Ti‒40% Al powders is promising for the obtainment of new photocatalytic active nanomaterials. © 2016, Pleiades Publishing, Ltd.
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| 3014. |
- Stepanova, Kristina V., et al.
(author)
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The structure and properties of nanoporous anodic oxide films on titanium aluminide
- 2019
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In: Kondensirovannye Sredy Mezhfaznye Granitsy. - Voronezh : Voronezh State University. - 1606-867X. ; 21:1, s. 135-145
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Journal article (peer-reviewed)abstract
- The paper presents a structural analysis of nanoporous oxide films formed by anodizing γTiAl (Ti-40 wt. %Al) samples in fluoride containing water and waterless electrolytes. Methods and methodology. Two groups of samples produced from (1) ingots and (2) sintered powder were used for anodizing. X-ray diffraction, X-ray electron spectroscopy, and scanning electron microscopy were used to analyse the structure of the films. The band gap values of anodized powder samples were estimated based on their UV-vis absorption spectra. The reaction of degradation of methyl orange under UV-vis irradiation was used to examine the photocatalytic activity of anodized TiAl powder. Results. Anodizing performed under optimal conditions in a 10 % H2SO4+0.15 % HF water electrolyte for both groups of samples results in the formation of self-organized nanoporous films of about 350 nm thickness with effective pore diameter <dp>= (70±10) nm. All the studied oxide films are heterogeneous, consist mostly of TiO2 : Al2O3 in a ratio of approximately 1:1, and have an X-ray amorphous structure. The optical band gap value of anodized powders determined by their UV absorption was Eg∌2.5 eV. It is much less than Eg of nanotubular titanium dioxide (Eg∌3.4 eV). The study also found that the concentration of methyl orange decreases under visible light irradiation in the presence of anodized TiAl powder. Conclusion. Photocatalytic activity of the developed heterogeneous films might be initiated by the visible light irradiation (λ∌480-510 nm). In other words, the new composite "TiAl powder/TiO2-Al2O3 nanoporous oxide" exhibits activity under the visible light radiation which results in the photocatalytic degradation of methyl orange. The obtained results can be successfully used for the production of new powder nanomaterials which show photocatalytic activity under visible light irradiation.
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| 3015. |
- Steuber, Thomas, et al.
(author)
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Comparison of free and total forms of serum human kallikrein 2 and prostate-specific antigen for prediction of locally advanced and recurrent prostate cancer
- 2007
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In: Clinical Chemistry. - : Oxford University Press (OUP). - 0009-9147 .- 1530-8561. ; 53:2, s. 233-240
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Journal article (peer-reviewed)abstract
- Background: We evaluated the association of total and free forms of serum human kallikrein 2 (hK2) and prostate-specific antigen (PSA) with prostate cancers of unfavorable prognosis. Methods: We retrospectively measured total PSA (tPSA), free PSA (fPSA), and total hK2 (thK2) in preoperative serum samples from 867 men [and assessed free hK2 (fhK2) measured in 577 of these men] treated with radical prostatectomy for clinically localized prostate cancer. Associations between biomarker concentrations and extracapsular extension, seminal vesicle invasion, and biochemical recurrence (BCR) were evaluated. A subset of patients with PSA <= 10 mu g/L, the group most commonly seen in clinical practice in the US, was analyzed. Results: thK2 was the strongest predictor of extracapsular extension and seminal vesicle invasion (areas under the ROC curve [AUC], 0.662 and 0.719, respectively), followed by tPSA (AUC, 0.654 and 0.663). All biomarkers were significant predictors of BCR. hK2 forms, but not PSA forms, remained highly significant for predicting BCR in the low-PSA group. Combining tPSA, fPSA, and thK2 in a multivariable model improved prediction compared with any biomarker used individually (AUC, 0.711, 0.755, and 0.752 for this combination predicting extracapsular extension, seminal vesicle invasion, and BCR, respectively; P < 0.001 for all). Conclusions: Increased concentrations of hK2 in the blood are significantly associated with unfavorable features of prostate cancer, and thK2 is predictive of locally advanced and recurrent cancer in patients with PSA <= <= 10 mu g/L. Independent of tPSA and fPSA, hK2 predicts unfavorable prognosis. (c) 2007 American Association for Clinical Chemistry
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| 3016. |
- Stoy, Paul C., et al.
(author)
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A data-driven analysis of energy balance closure across FLUXNET research sites: The role of landscape scale heterogeneity
- 2013
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In: Agricultural and Forest Meteorology. - : Elsevier BV. - 1873-2240 .- 0168-1923. ; 171, s. 137-152
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Journal article (peer-reviewed)abstract
- The energy balance at most surface-atmosphere flux research sites remains unclosed. The mechanisms underlying the discrepancy between measured energy inputs and outputs across the global FLUXNET tower network are still under debate. Recent reviews have identified exchange processes and turbulent motions at large spatial and temporal scales in heterogeneous landscapes as the primary cause of the lack of energy balance closure at some intensively-researched sites, while unmeasured storage terms cannot be ruled out as a dominant contributor to the lack of energy balance closure at many other sites. We analyzed energy balance closure across 173 ecosystems in the FLUXNET database and explored the relationship between energy balance closure and landscape heterogeneity using MODIS products and GLOBEstat elevation data. Energy balance closure per research site (C-EBS)averaged 0.84 +/- 0.20, with best average closures in evergreen broadleaf forests and savannas (0.91-0.94) and worst average closures in crops, deciduous broadleaf forests, mixed forests and wetlands (0.70-0.78). Half-hourly or hourly energy balance closure on a percent basis increased with friction velocity (u.) and was highest on average under near-neutral atmospheric conditions. C-EBS was significantly related to mean precipitation, gross primary productivity and landscape-level enhanced vegetation index (EVI) from MODIS, and the variability in elevation, MODIS plant functional type, and MODIS EVI. A linear model including landscape-level variability in both EVI and elevation, mean precipitation, and an interaction term between EVI variability and precipitation had the lowest Akaike's information criterion value. C-EBS in landscapes with uniform plant functional type approached 0.9 and C-EBS in landscapes with uniform EVI approached 1. These results suggest that landscape-level heterogeneity in vegetation and topography cannot be ignored as a contributor to incomplete energy balance closure at the flux network level, although net radiation measurements, biological energy assimilation, unmeasured storage terms, and the importance of good practice including site selection when making flux measurements should not be discounted. Our results suggest that future research should focus on the quantitative mechanistic relationships between energy balance closure and landscape-scale heterogeneity, and the consequences of mesoscale circulations for surface-atmosphere exchange measurements. (C) 2012 Elsevier B.V. All rights reserved.
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| 3017. |
- Strömgren, Magnus, et al.
(author)
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Factors shaping workplace segregation between natives and immigrants
- 2014
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In: Demography. - : Springer. - 0070-3370 .- 1533-7790. ; 51:2, s. 645-671
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Journal article (peer-reviewed)abstract
- Research on segregation of immigrant groups is increasingly turning its attention from residential areas toward other important places, such as the workplace, where immigrants can meet and interact with members of the native population. This article examines workplace segregation of immigrants. We use longitudinal, georeferenced Swedish population register data, which enables us to observe all immigrants in Sweden for the period 1990–2005 on an annual basis. We compare estimates from ordinary least squares with fixed-effects regressions to quantify the extent of immigrants' self-selection into specific workplaces, neighborhoods, and partnerships, which may bias more naïve ordinary least squares results. In line with previous research, we find lower levels of workplace segregation than residential segregation. The main finding is that low levels of residential segregation reduce workplace segregation, even after we take into account intermarriage with natives as well as unobserved characteristics of immigrants such as willingness and ability to integrate into the host society. Being intermarried with a native reduces workplace segregation for immigrant men but not for immigrant women.
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| 3018. |
- Stüber, Moritz, et al.
(author)
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Multi-scale mosaics in top-down pest control by ants from natural coffee forests to plantations
- 2021
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In: Ecology. - : Wiley. - 0012-9658 .- 1939-9170. ; 102:7
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Journal article (peer-reviewed)abstract
- While top-down control plays an important role in shaping both natural and agricultural food webs, we lack insights into how top-down control effects vary across spatial scales. We used a multi-scale survey of top-down control of coffee pests and diseases by arboreal ants to examine if colony location creates a small-scale mosaic in top-down control around trees and if the strength of that control varies between sites at the landscape scale. We investigated pest and disease levels on coffee shrubs at different distances from shade trees with and without a Crematogaster spp. ant colony in 59 sites along a coffee management intensity gradient in southwestern Ethiopia. Within sites, ants significantly suppressed herbivory and coffee leaf rust at distances less than 10 m from nesting trees. Top-down control varied between sites, with stronger top-down control of free-feeding herbivory near ant colonies at sites with lower management intensity and stronger top-down control of a skeletonizer at sites with higher canopy cover. We conclude that the strength of top-down control by ants is highly heterogeneous across spatial scales, as a consequence of the biology of the predator at the small scale and herbivore density or changes in herbivore–ant interactions at the landscape scale.
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| 3019. |
- Styhre, Alexander, 1971, et al.
(author)
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Management regimes in science-based innovation: control and uncertainty during early phases of new drug development
- 2011
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In: Technology Analysis and Strategic Management. - : Informa UK Limited. - 0953-7325 .- 1465-3990. ; 23:5, s. 567-581
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Journal article (peer-reviewed)abstract
- The international pharmaceutical industry is facing a challenge in terms of being able to deliver new and innovative drugs at lower cost. During the last 10 years, a range of new scientific procedures and technologies has been introduced into the industry, partially derived from the advancement of genomics research. However, to date, few have resulted in new registered drugs. In addition to the new technologies, various managerial techniques and methods have been introduced with the intention of increasing the transparency of operations. This paper reports on a study of how scientists during the early phases of new drug development conceive of this present management regime emphasising quantitative output. Thinking of new drug development as an intellectual pursuit in order to understand the elementary mechanisms of the biological organisms on the molecular level, scientists call for an understanding and adjustment of the managerial techniques structuring this work, accompanied by ambiguities and uncertainty.
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| 3020. |
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