Removal of Vanadium(III) and Molybdenum(V) from Wastewater Using Posidonia oceanica (Tracheophyta) Biomass

The use of dried and re-hydrated biomass of the seagrass Posidonia oceanica was investigated as an alternative and –low-cost biomaterial for removal of vanadium(III) and molybdenum(V) from wastewaters. Initial characterisation of this biomaterial identified carboxylic groups on the cuticle as potentially responsible for cation sorption, and confirmed the toxic-metal bioaccumulation. The combined effects on biosorption performance of equilibrium pH and metal concentrations were investigated in an ideal single-metal system and in more real-life multicomponent systems. There were either with one metal (vanadium or molybdenum) and sodium nitrate, as representative of high ionic strength systems, or with the two metals (vanadium and molybdenum). For the single-metal solutions, the optimum was at pH 3, where a significant proportion of vanadium was removed (ca. 70%) while there was ca. 40% adsorption of molybdenum. The data obtained from the more real-life multicomponent systems showed that biosorption of one metal was improved both by the presence of the other metal and by high ionic strength, suggesting a synergistic effect on biosorption rather than competition. There data ware used for the development of a simple multi-metal equilibrium model based on the non-competitive Langmuir approach, which was successfully fitted to experimental data and represents a useful support tool for the prediction of biosorption performance in such real-life systems. Overall, the results suggest that biomass of P. oceanica can be used as an efficient biosorbent for removal of vanadium(III) and molybdenum(V) from aqueous solutions. This process thus offers an eco-compatible solution for the reuse of the waste material of leaves that accumulate on the beach due to both human activities and to storms at sea.     

Policy Strategies to Promote Eco‐Innovation

This article elaborates an integrated policy framework, including policy features and specific measures that can be implemented to mitigate the barriers to eco‐innovations. We claim that factors inhibiting the development and uptake of eco‐innovations are multifaceted and stem from different sources. This systems view, which highlights the multilayered conception of the obstacles to eco‐innovation, calls for a combination of environmental and technology policies adapted to the different barriers and characteristics of the technologies. Drawing on evolutionary economics, the article sheds light on the appropriate combinations of framework conditions and instruments that are most effective to promote eco‐innovation, considering different barriers and eco‐innovation types (process/product, mature/immature, and radical/incremental).     

A dinuclear copper(II) complex with a Cu(O, N-O)Cu bridging core: structural and magnetic (experimental and density functional theory) studies

The molecular and electronic structure, along with the magnetic properties of a dinuclear complex in which two copper ions interact through a phenoxo oxygen atom and an oximato group are presented. The complex [CuL³Cu(O₂CCH₃)]3H₂O ·  0.5CH₃OH (3) crystallizes in the monoclinic space group Cc, with a=28.432(2) Å, b=12.305(1) Å, c=13.159(1) Å and β=99.580(9)°. The X-ray molecular structure shows that the core of the molecule comprising the two metal ions and the seven neighboring donors is nearly planar. The copper(II) ions were found to be antiferromagnetically coupled with a singlet-triplet splitting of 764(4) cm⁻¹. Density Functional Theory (DFT) showed that the magnetic orbitals are largely delocalized towards the bridging area, and an antiferromagnetic interaction in good agreement with the experimental data was computed using the Broken Symmetry (BS) formalism to obtain the energy of the singlet state.     

Physical performance in kidney transplanted patients: a study on desert trekking

Physical performance of kidney transplanted patients in challenging environments, such as deserts, has been poorly studied. Six kidney transplanted (T: 5 males, 1 female; 45±6 yrs) and 8 control (C: 5 males, 3 females; 49±13 yrs) subjects participated in a 5-day desert trek. Blood pressure, hydration status (Height2/Rz by bioimpedance), heart rate, energy expenditure (by SenseWear Pro Armband) and walking velocities were recorded during each daily trekking stage (GPS-assisted wearable devices). Systo-diastolic blood pressure did not differ between C (119/77±12/8 mmHg) and T (121/77±10/6 mmHg) groups throughout the study. The hydration status was stable from day 1 (Ht2/Rz: 64±13 cm2/Ohm in T and 59±12 cm2/Ohm in C subjects) to day 5 (66±11 cm2/Ohm in T and 61±13 cm2/Ohm in C subjects) in both groups. Two patients on steroid treatment showed a relative hyperhydration. Mean heart rate did not differ between T (135±10 bpm) and C (136±5 bpm) subjects throughout the study, although a reduction from day 1 to day 5 was observed in T subjects only (p<0.05 vs C group). No differences were found between T and C group in walking velocity (1.7±0.6 km/h in T and 1.7±0.5 km/h in C group); mean intensity of physical activity was 3.4±0.5 METs in T and 3.3±0.6 METs in C group during each trekking stage. Negligible differences were observed in cardiovascular, metabolic and hydration status adaptations to desert trekking between selected T and C individuals. T subjects with creatinine clearance > 55 ml/min showed acceptable physical performance and acclimatization to desert environment, suggesting a good long-term outcome of transplantation.     

A leucine-rich diet and exercise affect the biomechanical characteristics of the digital flexor tendon in rats after nutritional recovery

An increase in the capacity of athletic performance depends on adequate nutrition, which ensures optimal function of the musculoskeletal system, including tendon stability. However, little is known about the status of tendons and extracellular matrix modifications during malnutrition and nutritional recovery when leucine is used in response to exercise conditioning. The purpose of this study was to evaluate the collagen content and biomechanical aspects of the deep digital flexor tendon (DDFT) in malnourished rats submitted to nutritional recovery (control diet or leucine-rich diet) and aerobic physical activity. After 60 days of undernourishment (6% protein diet), the malnourished rats were subsequently nutritionally recovered with a control diet or leucine-rich diet and trained or not (swimming, without overload) for 5 weeks. The biomechanical analysis and quantification of hydroxyproline were assessed in the DDFT in all experimental groups. The leucine-rich diet increased hydroxyproline content in the tension region, independently of the training. In the compression region, hydroxyproline content was higher in the malnourished and leucine-trained groups. Biomechanical analysis showed a lower load in the malnourished and all-trained groups. The lowest stress was observed with control-trained animals. The nutritional-recovered groups showed higher strain values corresponding to control group, while the lowest values were observed in malnourished and trained groups. The results suggest that a leucine-rich diet stimulates collagen synthesis of the DDFT, especially when in combination with physical exercise, and seems to determine the increase of resistance and the biomechanical characteristics of tendons.     

MORPHOLOGICAL STUDIES OF SOME MARINE MASTOGLOIA (BACILLARIOPHYCEAE) BELONGING TO SECTION SULCATAE,INCLUDING THE DESCRIPTION OF NEW SPECIES

Epiphytic diatoms on seagrass and seaweed were collected from tropical (e.g., Siladen Island, Celebes Sea, Indonesia and Phú Bài, China Sea, Vietnam), subtropical (e.g., Sharm el‐Sheikh, Red Sea, Egypt), and temperate regions (e.g., Patmos Island, Greece) in 2000, 2005, and 2006. Eight species of Mastogloia, belonging to the section Sulcatae, are described mainly through scanning electron microscopy, including two new species to science, M. oculoides and M. sergiana. These species show a differently shaped median depression on the external valve face between the raphe‐sternum and the valve margin. Moreover, they lack a developed conopeum or pseudoconopeum, which covers the median depression in other species of the section Sulcatae. This study gives new insights on the ultrastructure of the Mastogloia's valves and provides an update of their current geographical distribution.     

Epiphytic diatom communities on intertidal seaweeds from Iceland

Epiphytic diatom communities on macroalgae from Iceland coastal waters were investigated during July 2005. Ten species of seaweeds have been collected belonging to brown, red and green algae. The analysis of epiphytic diatom community was carried out under scanning electron microscopy. The epiphytic diatom abundances varied from 7 ± 5 to 7524 ± 3491 cells mm⁻². Erect growth forms were the most abundant, representing on average 50% of the total diatoms (Achnanthes cf. brevipes var. parvula, Tabularia investiens, T. fasciculata, Hyalosira cf. delicatula, Gomphoseptatum aestuarii, Pseudogomphonema plinskii), followed by adnate (29%) (Cocconeis stauroneiformis, C. scutellum) and motile forms (21%) (Nitzschia cf. amphibia and Navicula perminuta). Highly branched seaweeds with articulated thallus surface, offering a number of microenvironments to be occupied by the epiphytes, showed a high level of colonization, mainly due to erect and motile diatoms. Flat thalli with smooth surface allowed for the growth of mainly erect diatoms.     

Diatom invasion in the antarctic hexactinellid sponge Scolymastra joubini

Sponges often host large amounts of symbionts, mainly represented by cyanobacteria and dinoflagellates. Recent findings show a widespread presence of symbiotic diatoms living inside antarctic demosponges. In this paper, the invasion by large populations of the diatom Melosira sp. into specimens of the hexactinellid sponge Scolymastra joubini is reported. SEM analyses support the hypothesis that the embedded living diatoms have a negative impact on sponge tissues, leading to degenerative processes. Received: 1 December 1999 / Accepted: 20 February 2000     

Synthesis and characterization of new oligomeric and polymeric complexes based on the [Cu(bpca)] unit [Hbpca = bis(2-pyridylcarbonyl)amine]

Five novel bpca-based Cu(II) polynuclear coordination compounds [Hbpca = bis(2-pyridylcarbonyl)amine] were prepared using the [Cu(bpca)(H₂O)₂](NO₃)·2H₂O (1) building block and characterized by single crystal X-ray diffraction. We have also isolated and characterized two new crystal forms of the starting species, with lower water contents. Three of the new products are dinuclear complexes obtained by reacting 1 with different rigid or flexible spacer ligands: [Cu₂(bpca)₂(H₂O)₂(bipy)](NO₃)₂·6H₂O (2) (bipy = 4,4′-bipyridine) and [Cu₂(bpca)₂(H₂O)₂(bpete)](NO₃)₂·xH₂O (3) [bpete = (E)-1,2-di(pyridin-4-yl)ethane] are linear dumbbell-like species with Cu?Cu separations of 11.075 and 13.275 Å, respectively. The third dinuclear compound, [Cu₂(bpca)₂(H₂O)₂(bpx)](NO₃)₂·8H₂O (4) [bpx = 1,4-bis((1H-pyrazol-1-yl)methyl)benzene], with the flexible bpx ligand, assumes an unusual S-shaped conformation and shows a quite shorter Cu?Cu contact of 6.869 Å only. We have also obtained a chiral 1D neutral polymeric complex, [Cu₃(bpca)₂(bipy)₃(NO₃)₄]·6H₂O (5), that shows a central linear -Cu-bipy-Cu- chain, with all these Cu atoms connected to two lateral [Cu(bpca)(NO₃)₂]⁻ groups on two opposite sides by means of bipy spacers. An unprecedented type of Cu(II) neutral trinuclear complex, [Cu₃(bpca)₂(H₂O)₂(NO₃)₂] (6), was obtained which has a centrosymmetric structure with two external [Cu(bpca)(NO₃)₂]⁻ units chelating on a central copper atom via the two pairs of carbonyl groups of the bpca ligands. The central metal is octahedral with two axial water molecules, while the two lateral Cu atoms are in square pyramidal geometry; the Cu?Cu separation is 5.205 Å. The magnetic properties of 6 have been rationalized through a ferromagnetic coupling between the central metal ion and the peripheral ones which are coupled by a smaller antiferromagnetic interaction. DFT calculations have been also performed in order to give a better insight into magnetic interactions.