| 1. |
- Staude, I. R., et al.
(författare)
-
Directional turnover towards larger-ranged plants over time and across habitats
- 2022
-
Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 25:2, s. 466-82
-
Tidskriftsartikel (refereegranskat)abstract
- Species turnover is ubiquitous. However, it remains unknown whether certain types of species are consistently gained or lost across different habitats. Here, we analysed the trajectories of 1827 plant species over time intervals of up to 78 years at 141 sites across mountain summits, forests, and lowland grasslands in Europe. We found, albeit with relatively small effect sizes, displacements of smaller- by larger-ranged species across habitats. Communities shifted in parallel towards more nutrient-demanding species, with species from nutrient-rich habitats having larger ranges. Because these species are typically strong competitors, declines of smaller-ranged species could reflect not only abiotic drivers of global change, but also biotic pressure from increased competition. The ubiquitous component of turnover based on species range size we found here may partially reconcile findings of no net loss in local diversity with global species loss, and link community-scale turnover to macroecological processes such as biotic homogenisation.
|
|
| 2. |
- Ergeneman, O., et al.
(författare)
-
Morphology, structure and magnetic properties of cobalt-nickel films obtained from acidic electrolytes containing glycine
- 2011
-
Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686 .- 1873-3859. ; 56:3, s. 1399-1408
-
Tidskriftsartikel (refereegranskat)abstract
- This paper focuses on the development and optimization of electroplated cobalt-nickel (CoNi) alloys for use in biomedical microdevices. CoNi films were electrodeposited from glycine-containing electrolyte solutions at acidic pH. The influence of pH (2.5-5), temperature (55 and 80 degrees C). current density (from -5 to -40 mA cm(-2)), glycine concentration (0.5 and 1 mol dm(-3)) and the nature of the metal salts (chlorides or sulphates) on the composition and the magnetic properties of the films were systematically analyzed. The cobalt content varied between 50 and 83 wt% depending on the applied conditions. As a result, deposits showed variable morphologies, different structures (either hexagonal close-packed (hcp) or mixed hcp and face-centered cubic phases) and tunable magnetic properties, ranging from semi-hard (18.51 kA m(-1). i.e. 233 Oe) to very soft (1.43 kA m(-1), i.e. 18 Oe). To understand the role of glycine in this system, a comparison of the electrochemical processes, and the structural and magnetic properties is made for samples produced in glycine-containing and glycine-free baths. (C) 2010 Elsevier Ltd. All rights reserved.
|
|
| 3. |
- Sotiriou, Georgios A., et al.
(författare)
-
Thermal Energy Dissipation by SiO2-Coated Plasmonic-Superpararnagnetic Nanoparticles in Alternating Magnetic Fields
- 2013
-
Ingår i: Chemistry of Materials. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 25:22, s. 4603-4612
-
Tidskriftsartikel (refereegranskat)abstract
- Multifunctional nanoparticles show great potential in the biomedical field and may help the diagnosis and therapy of diseases. Superparamagnetic nanoparticles are especially attractive because of their ability to dissipate thermal energy in an alternating magnetic field. Furthermore, plasmonic nanoparticles can be effectively used in non- or minimally invasive therapy of tumors exploiting their plasmonic photothermal effect. Here, hybrid plasmonicmagnetic Ag/Fe2O3 nanoparticles are made by flame aerosol technology. These nanoparticles can be in situ encapsulated with an amorphous nanothin SiO2 film to facilitate their dispersion and block any toxicity from Ag/Fe2O3. Detailed physicochemical characterization, including electron microscopy, electron dispersive X-ray spectroscopy, and X-ray diffraction, is performed. Furthermore, their magnetic properties are characterized in detail by monitoring their hysteresis, first-order-reversal-curves, and isothermal remanent magnetization. Finally, the effect of SiO2 and Agcontent on the specific absorption rate (SAR) of the hybrid Ag/Fe2O3 nanoparticles is investigated. The obtained understanding will help the rational design and engineering of multifunctional hybrid nanoprobes targeting specific biomedical applications.
|
|
| 4. |
- Staude, I. R., et al.
(författare)
-
Replacements of small- by large-ranged species scale up to diversity loss in Europe's temperate forest biome
- 2020
-
Ingår i: Nature Ecology & Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 4, s. 802-808
-
Tidskriftsartikel (refereegranskat)abstract
- The loss of biodiversity at the global scale has been difficult to reconcile with observations of no net loss at local scales. Vegetation surveys across European temperate forests show that this may be explained by the replacement of small-ranged species with large-ranged ones, driven by nitrogen deposition. Biodiversity time series reveal global losses and accelerated redistributions of species, but no net loss in local species richness. To better understand how these patterns are linked, we quantify how individual species trajectories scale up to diversity changes using data from 68 vegetation resurvey studies of seminatural forests in Europe. Herb-layer species with small geographic ranges are being replaced by more widely distributed species, and our results suggest that this is due less to species abundances than to species nitrogen niches. Nitrogen deposition accelerates the extinctions of small-ranged, nitrogen-efficient plants and colonization by broadly distributed, nitrogen-demanding plants (including non-natives). Despite no net change in species richness at the spatial scale of a study site, the losses of small-ranged species reduce biome-scale (gamma) diversity. These results provide one mechanism to explain the directional replacement of small-ranged species within sites and thus explain patterns of biodiversity change across spatial scales.
|
|
| 5. |
- Alison, Lauriane, et al.
(författare)
-
Pickering and Network Stabilization of Biocompatible Emulsions Using Chitosan-Modified Silica Nanoparticles
- 2016
-
Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 32:50, s. 13446-13457
-
Tidskriftsartikel (refereegranskat)abstract
- Edible solid particles constitute an attractive alternative to surfactants as stabilizers of food-grade emulsions for products requiring a long-term shelf life. Here, we report on a new approach to stabilize edible emulsions using silica nanoparticles modified by noncovalently bound chitosan oligomers. Electrostatic modification with chitosan increases the hydrophobicity of the silica nanoparticles and favors their adsorption at the oil water interface. The interfacial adsorption of the chitosan-modified silica particles enables the preparation of oil-in-water emulsions with small droplet sizes of a few micrometers through high-pressure homogenization. This approach enables the stabilization of food-grade emulsions for more than 3 months. The emulsion structure and stability can be effectively tuned by controlling the extent of chitosan adsorption on the silica particles. Bulk and interfacial rheology are used to highlight the two stabilization mechanisms involved. Low chitosan concentration (1 wt % with respect to silica) leads to the formation of a viscoelastic film of particles adsorbed at the oil water interface, enabling Pickering stabilization of the emulsion. By contrast, a network of agglomerated particles formed around the droplets is the predominant stabilization mechanism of the emulsions at higher chitosan content (5 wt % with respect to silica). These two pathways against droplet coalescence and coarsening open up different possibilities to engineer the long-term stabilization of emulsions for food applications.
|
|
| 6. |
- Ansari, Shaquib Rahman, 1993-, et al.
(författare)
-
Hyperthermia-Induced In Situ Drug Amorphization by Superparamagnetic Nanoparticles in Oral Dosage Forms
- 2022
-
Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 14:19, s. 21978-21988
-
Tidskriftsartikel (refereegranskat)abstract
- Superparamagnetic iron oxide nanoparticles (SPIONs) generate heat upon exposure to an alternating magnetic field (AMF), which has been studied for hyperthermia treatment and triggered drug release. This study introduces a novel application of magnetic hyperthermia to induce amorphization of a poorly aqueous soluble drug, celecoxib, in situ in tablets for oral administration. Poor aqueous solubility of many drug candidates is a major hurdle in oral drug development. A novel approach to overcome this challenge is in situ amorphization of crystalline drugs. This method facilitates amorphization by molecular dispersion of the drug in a polymeric network inside a tablet, circumventing the physical instability encountered during the manufacturing and storage of conventional amorphous solid dispersions. However, the current shortcomings of this approach include low drug loading, toxicity of excipients, and drug degradation. Here, doped SPIONs produced by flame spray pyrolysis are compacted with polyvinylpyrrolidone and celecoxib and exposed to an AMF in solid state. A design of experiments approach was used to investigate the effects of SPION composition (Zn0.5Fe2.5O4 and Mn0.5Fe2.5O4), doped SPION content (10–20 wt %), drug load (30–50 wt %), and duration of AMF (3–15 min) on the degree of drug amorphization. The degree of amorphization is strongly linked to the maximum tablet temperature achieved during the AMF exposure (r = 0.96), which depends on the SPION composition and content in the tablets. Complete amorphization is achieved with 20 wt % Mn0.5Fe2.5O4 and 30 wt % celecoxib in the tablets that reached the maximum temperature of 165.2 °C after 15 min of AMF exposure. Furthermore, manganese ferrite exhibits no toxicity in human intestinal Caco-2 cell lines. The resulting maximum solubility of in situ amorphized celecoxib is 5 times higher than that of crystalline celecoxib in biorelevant intestinal fluid. This demonstrates the promising capability of SPIONs as enabling excipients to magnetically induce amorphization in situ in oral dosage forms.
|
|
| 7. |
- Asad, Shno, et al.
(författare)
-
Proteomics-Informed Identification of Luminal Targets For In Situ Diagnosis of Inflammatory Bowel Disease
- 2021
-
Ingår i: Journal of Pharmaceutical Sciences. - : Elsevier. - 0022-3549 .- 1520-6017. ; 110:1, s. 239-250
-
Tidskriftsartikel (refereegranskat)abstract
- Inflammatory bowel disease (IBD) is a chronic condition resulting in impaired intestinal homeostasis. Current practices for diagnosis of IBD are challenged by invasive, demanding procedures. We hypothesized that proteomics analysis could provide a powerful tool for identifying clinical biomarkers for non-invasive IBD diagnosis. Here, the global intestinal proteomes from commonly used in vitro and in vivo models of IBD were analyzed to identify apical and luminal proteins that can be targeted by orally delivered diagnostic agents. Global proteomics analysis revealed upregulated plasma membrane proteins in intestinal segments of proximal- and distal colon from dextran sulfate sodium-treated mice and also in inflamed human intestinal Caco-2 cells pretreated with pro-inflammatory agents. The upregulated colon proteins in mice were compared to the proteome of the healthy ileum, to ensure targeting of diagnostic agents to the inflamed colon. Promising target proteins for future investigations of non-invasive diagnosis of IBD were found in both systems and included Tgm2/TGM2, Icam1/ICAM1, Ceacam1/CEACAM1, and Anxa1/ANXA1. Ultimately, these findings will guide the selection of appropriate antibodies for surface functionalization of imaging agents aimed to target inflammatory biomarkers in situ.
|
|
| 8. |
- De Schuyter, Wim, et al.
(författare)
-
Declining potential nectar production of the herb layer in temperate forests under global change
- 2024
-
Ingår i: Journal of Ecology. - 0022-0477 .- 1365-2745. ; 112:4, s. 832-847
-
Tidskriftsartikel (refereegranskat)abstract
- Wild pollinators are crucial for ecosystem functioning and human food production and often rely on floral resources provided by different (semi-) natural ecosystems for survival. Yet, the role of European forests, and especially the European forest herb layer, as a potential provider of floral resources for pollinators has scarcely been quantified.In this study, we measured the potential nectar production (PNP) of the forest herb layer using resurvey data across 3326 plots in temperate forests in Europe, with an average time interval of 41 years between both surveys in order to assess (i) the importance of the forest herb layer in providing nectar for wild pollinators, (ii) the intra-annual variation of PNP, (iii) the overall change in PNP between survey periods and (iv) the change in intra-annual variation of PNP between survey periods. The PNP estimates nectar availability based on the relative cover of different plant species in the forest herb layer. Although PNP overestimates actual nectar production, relative differences amongst plots provide a valid and informative way to analyse differences across time and space.Our results show that the forest herb layer has a large potential for providing nectar for wild pollinator communities, which is greatest in spring, with an average PNP of almost 16 g sugar/m2/year. However, this potential has drastically declined (mean plot-level decline >24%).Change in light availability, associated with shifts in canopy structure and canopy composition, is the key driver of temporal PNP changes.Synthesis. Our study shows that if management activities are carefully planned to sustain nectar-producing plant species for wild pollinators, European forest herb layers and European forests as a whole can play key roles in sustaining wild pollinator populations.
|
|
| 9. |
- Hempel, Nele-Johanna, et al.
(författare)
-
The Effect of the Molecular Weight of Polyvinylpyrrolidone and the Model Drug on Laser-Induced In Situ Amorphization
- 2021
-
Ingår i: Molecules. - : MDPI. - 1431-5157 .- 1420-3049. ; 26:13
-
Tidskriftsartikel (refereegranskat)abstract
- Laser radiation has been shown to be a promising approach for in situ amorphization, i.e., drug amorphization inside the final dosage form. Upon exposure to laser radiation, elevated temperatures in the compacts are obtained. At temperatures above the glass transition temperature (T-g) of the polymer, the drug dissolves into the mobile polymer. Hence, the dissolution kinetics are dependent on the viscosity of the polymer, indirectly determined by the molecular weight (M-w) of the polymer, the solubility of the drug in the polymer, the particle size of the drug and the molecular size of the drug. Using compacts containing 30 wt% of the drug celecoxib (CCX), 69.25 wt% of three different M-w of polyvinylpyrrolidone (PVP: PVP12, PVP17 or PVP25), 0.25 wt% plasmonic nanoaggregates (PNs) and 0.5 wt% lubricant, the effect of the polymer M-w on the dissolution kinetics upon exposure to laser radiation was investigated. Furthermore, the effect of the model drug on the dissolution kinetics was investigated using compacts containing 30 wt% of three different drugs (CCX, indomethacin (IND) and naproxen (NAP)), 69.25 wt% PVP12, 0.25 wt% PN and 0.5 wt% lubricant. In perfect correlation to the Noyes-Whitney equation, this study showed that the use of PVP with the lowest viscosity, i.e., the lowest M-w (here PVP12), led to the fastest rate of amorphization compared to PVP17 and PVP25. Furthermore, NAP showed the fastest rate of amorphization, followed by IND and CCX in PVP12 due to its high solubility and small molecular size.
|
|
| 10. |
- Hempel, Nele-Johanna, et al.
(författare)
-
The Influence of Drug-Polymer Solubility on Laser-Induced In Situ Drug Amorphization Using Photothermal Plasmonic Nanoparticles
- 2021
-
Ingår i: Pharmaceutics. - : MDPI. - 1999-4923 .- 1999-4923. ; 13:6
-
Tidskriftsartikel (refereegranskat)abstract
- In this study, laser-induced in situ amorphization (i.e., amorphization inside the final dosage form) of the model drug celecoxib (CCX) with six different polymers was investigated. The drug-polymer combinations were studied with regard to the influence of (i) the physicochemical properties of the polymer, e.g., the glass transition temperature (T-g) and (ii) the drug-polymer solubility on the rate and degree of in situ drug amorphization. Compacts were prepared containing 30 wt% CCX, 69.25 wt% polymer, 0.5 wt% lubricant, and 0.25 wt% plasmonic nanoparticles (PNs) and exposed to near-infrared laser radiation. Upon exposure to laser radiation, the PNs generated heat, which allowed drug dissolution into the polymer at temperatures above its T-g, yielding an amorphous solid dispersion. It was found that in situ drug amorphization was possible for drug-polymer combinations, where the temperature reached during exposure to laser radiation was above the onset temperature for a dissolution process of the drug into the polymer, i.e., T-DStart. The findings of this study showed that the concept of laser-induced in situ drug amorphization is applicable to a range of polymers if the drug is soluble in the polymer and temperatures during the process are above T-DStart.
|
|
