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Magnetoresponsive, methacrylate-based 3D polymer networks containing hydrophilic/thermoresponsive, hydrophilic/pH-responsive and hydrophobic/metal chelating functionalities and oleic acid-coated magnetite nanoparticles, have been synthesized by conventional crosslinking radical polymerization and further evaluated as adsorbents for the removal of U(VI) ions from aqueous media. The adsorption properties of the networks prior and after magnetization regarding U(VI) ion removal from aqueous solutions of varying acidity and initial U(VI) concentration have been investigated. The effect of pH on the interaction of the adsorbents with U(VI) ions was shown to differ dramatically depending on solid phase composition, due to the fact that in the magnetite-loaded network, the Fe3O4 nanoparticles act as buffers by binding solution protons. Nevertheless, U(VI) adsorption on both types of adsorbents follows the Langmuir adsorption isotherm and the value of their maximum adsorption capacity is qmax = ∼0.02 mol kg−1 showing no statistically significant differences. The magnetic properties of these materials make their removal and adsorbed uranium separation from the aqueous phase quite simple by using an external magnetic field. © 2017 Elsevier Ltd 97 138 146 138-146

Colloidal polyvinylpyrrolidone-stabilized Pd nanoparticles were embedded within 1,2-bis(2-iodoethoxy)ethane (BIEE)-crosslinked poly(2-dimethylamino)ethyl methacrylate homopolymer networks with defined structural characteristics. In the presented synthetic approach, the crosslinking step is realised in ambient conditions, thus avoiding nanoparticle agglomeration phenomena. These 3D polymer-based nanocomposite networks were evaluated as heterogeneous catalysts for Heck, Suzuki-Miyaura and Sonogashira coupling reactions. High catalytic activity and reusability was demonstrated in Heck reactions, substrate-specific outcomes were observed in Sonogashira couplings, while poor reactivity was observed in Suzuki-Miyaura couplings. The existing diversity in material structure and composition allows for further improvements leading to highly stable and robust 3D polymer-based nanocomposite heterogeneous catalysts that could find use in a wide range of transition metal-catalysed organic reactions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 1 2635 2641 2635-2641

The mechanical properties of structurally-defined magnetoactive polymer (co)networks synthesized from well-defined poly(2-dimethylamino)ethyl methacrylate (poly(DMAEMA)) homopolymers and diblock copolymers of poly(DMAEMA) with the hydrophobic n-butyl methacrylate (BuMA) were measured in compression. Magnetic nanoparticle composition varied from 0 to 30% wt and caused a 6-fold increase in the Young's modulus of the homopolymer networks (2.91 vs. 18.62 kPa) and a 12-fold increase in the modulus of diblock copolymer networks (0.76 vs. 9.1 kPa), with homopolymers being stiffer. Mathematical modeling revealed an exponential constitutive equation to predict accurately the mechanical response of the polymers. Furthermore, experiments were performed for the poroelastic behavior of the materials and their hydraulic conductivity was found to be independent of magnetic loading and network structure. In conclusion, the incorporation of magnetic nanoparticles strengthened the (co)network structure, while the synthetic approach employed for the DMAEMA-b-BuMA formation retained the linear, non-crosslinked architecture of BuMA, resulting in less stiff structures. This journal is © The Royal Society of Chemistry 2015. 5 20011 20019 20011-20019

After a timing preoperative staging, treatment of resectable pancreatic adenocarcinoma (PDAC) includes surgery and adjuvant therapies, the former representing the initial therapeutic option and the latter aiming to reduce the incidence of both distant metastases (chemotherapy) and locoregional failures (chemoradiotherapy). Herein, we provide a critical overview on the role of multimodal treatment in PDAC and on new opportunities related to current more active poli-chemotherapy regimens, targeted therapies, and the more recent immunotherapy approaches. Moreover, an analysis of pathological markers and clinical features able to help clinicians in the selection of the best therapeutic strategy will be discussed. Lastly, the role of neoadjuvant treatment of initially resectable disease will be considered mostly in patients whose malignancy shows morphological but not clinical or biological criteria of resectability. Depending on the results of these investigational studies, today a multidisciplinary approach can offer the best address therapy for these patients.

The fabrication of magnetoactive fibrous nanocomposite membranes based on poly(vinyl pyrrolidone) (PVP), poly(L-lactide) (PLLA) and pre-formed oleic acid coated magnetite nanoparticles (OA Fe3O4) is presented. The aforementioned materials have been prepared by means of the electrospinning technique following a single-step fabrication process. The PVP/PLLA/OA Fe 3O4 nanocomposite membranes were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) that provided information on the fiber diameters as well as on the morphological and dimensional characteristics of the OA Fe3O4 nanoparticles embedded within the fibers. The thermal stability of these materials was evaluated by means of thermal gravimetric analysis (TGA) measurements. Finally, vibrational sample magnetometry (VSM) analysis disclosed superparamagnetic behavior at room temperature. The combination of the hydrophilic, biocompatible and photo-crosslinkable PVP with the biodegradable PLLA and the superparamagnetic OA Fe3O4 nanoparticles within these materials allows for the future development of crosslinked fibrous magnetoactive nanocomposites exhibiting high stability in aqueous solutions, with potential use in biomedical and environmental applications. © 2013 Elsevier B.V. All rights reserved. 352 30 35 30-35

The fabrication of electrospun magnetoactive fibrous nanocomposite membranes based on the water-soluble and biocompatible poly(ethylene oxide) (PEO), the biocompatible and biodegradable poly(l-lactide) (PLLA) and preformed oleic acid-coated magnetite nanoparticles (OA.Fe3O4) is reported. Visualization of the membranes by electron microscopy techniques reveals the presence of continuous fibers of approximately 2 μm in diameter, with the magnetic nanoparticles being evenly distributed within the fibers, retaining at the same time their nanosized diameters (∼5 nm). Thermal gravimetric analysis measurements suggest that the magnetic nanoparticles embedded within the polymer fibers affect favorably the thermal stability of the membranes. Moreover, assessment of their magnetic characteristics by vibrating sample magnetometry discloses tunable superparamagnetic behavior at ambient temperature. For the first time, the biocompatibility and biodegradability of PEO/PLLA and the tunable magnetic activity of the OA.Fe3O4 are combined in the same drug delivery system, with N-acetyl-p-aminophenol (acetaminophen) as a proof-of-concept pharmaceutical. Furthermore, their heating ability under alternating current (AC) magnetic field conditions is evaluated using frequency of 110 kHz and corresponding magnetic field strength of 25 mT (19.9 kA/m). Consequently, these magnetoactive fibrous nanocomposites exhibit promising characteristics for future exploitation in magnetothermally triggered drug delivery. © 2013 American Chemical Society. 14 4436 4446 4436-4446

Sustained plant nutrient a vailability on reclaimed wellsites is critical to the successful restoration of crop productivity. This study evaluated topsoil replacement depth (TRD) (0, 50, 100, and 150% of mandatory TRD) and organic amendment [beef cattle feedlot manure, compost derived from straw-bedded cattle feedlot manure, wheat (Triticum aestivumL.) straw, alfalfa (Medicago sativaL.) hay, and unamended control] effects on nutrient uptake by a wheat crop at three abandoned gas wellsites in south-central Alberta. Grain N uptake increased by 0.055 kg ha-1 for each percent increase in TRD, reflecting the corresponding linear increase in grain N concentration. Low carbon to nitrogen (C:N) ratio amendments, particularly compost and alfalfa, were the most effective for improving grain N concentration and uptake. Conversely, N concentration and uptake were lowest for the high C:N (53:1) wheat straw amendment. Reclamation programs should, therefore, consider incorporation of the low C:N alfalfa or compost in order to safeguard against N deficiency in the first 1–2 yr following reclamation. Our results also show that high P amendments, such as manure and compost, are better choices for improving P uptake by spring wheat. These results emphasize the importance of topsoil replacement and amendment quality (C:N ratio and P concentration) in ensuring adequate N and P supply in the 1–2 yr following reclamation. Based on this, compost appears to be the best single amendment for ensuring enhanced uptake of both N and P on reclaimed wellsites in the short term. Key words: Topsoil replacement; organic amendments; reclamation; nitrogen; phosphorus

The magnitude and dynamics of soil gaseous fluxes play critical roles in the global gas balance; yet, these processes are not captured at sufficient temporal resolution by standard methods based on periodic sampling and surface chamber measurements. A novel method for continuous measurement of soil surface gas fluxes based on subsurface CO 2 and O 2 concentration gradient measurements was developed. We tested the gradient-based method under steady- and transient-state soil water content and temperature conditions and compared results with a state-of-the-art surface chamber CO 2 flux system. The new aspects of the method include fast-response sensors installed in the soil profile providing continuous record of concentration gradients coupled with concurrent estimates of water content-dependent gaseous diffusion coefficient enabling calculation of surface gaseous fluxes. Low-cost infrared sensors were used for CO 2 concentration measurements, and galvanic cells for O 2 measurements. An imposed CO 2 concentration gradient in a dry soil column resulted in a quasilinear CO 2 concentration profile and surface CO 2 flux in agreement with chamber-measured fluxes. A series of continuous concentration measurements under variable water content conditions and wetting events showed agreement with surface chamber measurements. Within several days of surface wetting, soil CO 2 concentrations attained 10 mL L −1 , one order of magnitude higher than ambient concentrations, whereas O 2 concentrations decreased. The gradient-based approach minimizes soil surface perturbations and provides insights into subsurface soil CO 2 and O 2 dynamics and the distribution and magnitude of soil respiration processes as related to soil environmental factors. The subsurface gradient-based measurement system represents an order-of-magnitude reduction in cost compared with research-grade surface chamber devices.

Changes in soil properties reflect the success or failure of reclamation practices on abandoned wellsites. We examined the effect on soil properties of four (0, 50, 100 and 150%) topsoil replacement depths (TRD) and five amendment treatments [compost, manure, wheat (Triticum aestivum L.) straw, alfalfa (Medicago sativa L.) hay, check] aimed at reclaiming three wellsites (Strathmore, Hesketh and Rosedale) in southcentral Alberta. TRD treatment differences were consistent across all wellsites, with 30 to 32% higher soil organic carbon (SOC) on the 150% TRD compared to the 0% TRD. Initially, the alfalfa treatment showed higher levels of nitrate-nitrogen (e.g., 26 mg kg-1 vs. 3 to 7 mg kg-1 for the other amendment treatments in the 15- to 30-cm depth at Strathmore in fall 1998), which was related to its rapid breakdown and mineralization of organic N. After 40 mo (June 1997-October 2000), the average amounts (n = 3 wellsites) of added C conserved near the soil surface were: compost (65 ±10% SE) > manure (45 ±16% SE) > alfalfa (28 ±11% SE) > straw (23 ± 6% SE). Our results show that organic amendments play an important role in improving soil properties related to long-term productivity of reclaimed wellsites, especially where topsoil is scarce or absent. Key words: Wellsite reclamation, topsoil depth, organic amendments, soil quality

The reclamation success of abandoned wellsites in agricultural areas depends on their capacity to sustain levels of biomass production similar to those which existed prior to soil disturbance. We examined the effect of four (0, 50, 100 and 150%) topsoil replacement depths (TRD) and five amendment treatments [compost, manure, alfalfa (Medicago sativa L.) hay, wheat (Triticum aestivum L.) straw, check) in the reclamation of three wellsites in south-central Alberta. The largest incremental effect of TRD on spring wheat response in the 4 yr (1997-2000) study occurred between the 0 and 50% treatments. Increasing TRD from 100 to 150% had little impact on crop response. Of the 20 treatments (four TRD × five amendments), the reclamation capacity of the 100% TRD-compost treatment ranked highest, being 19% higher than the baseline treatment (100% TRD-check). The lowest-ranking treatment overall , was the 0% TRD-straw treatment, which yielded 64% of the baseline treatment. Crop yield responses to organic amendments were larger when the recipient soil was lower in organic matter. Positive responses to one-time applications of organic amendments in the short-term (4 yr), advocate their use in soil reclamation of abandoned wellsites, despite a lingering question about the longevity of their beneficial effects. Key words: Soil reclamation, topsoil, organic amendments, natural gas wellsite