Recycling of polyurethanes from laboratory to industry, a journey towards the sustainability.

The recycling of any kind of plastic to convert it in valuable products is one of the main challenges of today's society. Besides, if the recycling process is itself green, then it would be a great achievement. This paper reviews the way covered from the first attempts of reusing the polyurethane (PU) scraps as a filler for cushions to the last chemical routes employing green recycling agents. Polyurethane is the 6th most used polymer all over the world with a production of 18 millions tons per year, which means a daily production of PU specialties greater than 1 million of cubic meters, equivalent to the volume of the Empire State Building. The thermostable nature of the majority of the polyurethanes specialties has made that the preferred solution for their recycling are the chemical recycling processes. Among them, glycolysis is the one that receives a greater attention from an industrial point of view, so this review puts the spotlight on it. However, the existing reviews in literature do not paid a special attention on glycolysis and only give a superficial description of the process. Nevertheless, in the present review, the scientific literature relative to glycolysis is completely reviewed, updated and ordered according the type of PU specialty recycled. Additionally, the other main chemical recycling processes are also revisited in a more extended and deeper way than in the previous approaches to this topic. Moreover, it is crucial to take into account that some of these technologies, which were described in the literature as promising technologies at laboratory scale are now commercial processes running at industrial scale. For that reason, it is essential to remark that the present review comprises not only a detailed state of art of the scientific literature on the subject, also includes a detailed revision of the past and running on pilot plants and industrial facilities, including several patents, which has never been covered in the current literature. Moreover, this review also describes the most recent studies employing crude glycerol (biodiesel subproduct) as an economic, sustainable and environmental friendly cleavage agent, which should lead the way to the industrial implantation of split-phase glycolysis in a near future, providing high quality recovered products, susceptible of replacing raw ones in the synthesis of new PU specialties. What is more, this review intends that any reader could know and understand the reactions involved in the polyurethane chemistry and recycling, the main polyurethanes types and the fundamentals of the recycling strategies in order to comprehend what are the advantages and drawbacks of each recycling process as starting point for looking for new advantageous alternatives from an environmental, technical and economic point of view. Broader context. This paper reviews the main advances in the polyurethane (PU) recycling field, from laboratory and academia processes to pilot plant and industrial scale ones, including the most relevant patents in the subject. Opposite to other common used plastics, PUs are not polymerization but condensation polymers, synthesized from polyols and isocyanates. The wide diversity of polyols and isocyanates allows the synthesis of numerous different compounds covering a huge range of applications. As a direct consequence of their commercial success, an increasing quantity of PU waste is being disposed by landfilling in the last decades. Such waste comprises not only post-consumer products but also scrap from slabstock manufacturing, which can reach the 10% of the total foam production. However, the massive enforcement of the environmental laws is pointing out a new route in the polymer waste removal sector based in the polymer recycling, and this fact has placed the research in waste treatment as one of the most prolific topics nowadays. In fact, polymer recycling processes have experienced a growing attention from the research and industrial worlds as a direct result of the enforcement of the environmental legislations. Hence, it is essential to develop new environmental sustainable recycling processes with the aim of conserving the natural resources, reducing the amount of waste disposed in landfills and enhancing the sustainability for forthcoming generation.

Targeting MT1-MMP as an ImmunoPET-Based Strategy for Imaging Gliomas.

BACKGROUND: A critical challenge in the management of Glioblastoma Multiforme (GBM) tumors is the accurate diagnosis and assessment of tumor progression in a noninvasive manner. We have identified Membrane-type 1 matrix metalloproteinase (MT1-MMP) as an attractive biomarker for GBM imaging since this protein is actively involved in tumor growth and progression, correlates with tumor grade and is closely associated with poor prognosis in GBM patients. Here, we report the development of an immunoPET tracer for effective detection of MT1-MMP in GBM models. METHODS: An anti-human MT1-MMP monoclonal antibody (mAb), LEM2/15, was conjugated to p-isothiocyanatobenzyl-desferrioxamine (DFO-NCS) for 89Zr labeling. Biodistribution and PET imaging studies were performed in xenograft mice bearing human GBM cells (U251) expressing MT1-MMP and non-expressing breast carcinoma cells (MCF-7) as negative control. Two orthotopic brain GBM models, patient-derived neurospheres (TS543) and U251 cells, with different degrees of blood-brain barrier (BBB) disruption were also used for PET imaging experiments. RESULTS: 89Zr labeling of DFO-LEM2/15 was achieved with high yield (>90%) and specific activity (78.5 MBq/mg). Biodistribution experiments indicated that 89Zr-DFO-LEM2/15 showed excellent potential as a radiotracer for detection of MT1-MMP positive GBM tumors. PET imaging also indicated a specific and prominent 89Zr-DFO-LEM2/15 uptake in MT1-MMP+ U251 GBM tumors compared to MT1-MMP- MCF-7 breast tumors. Results obtained in orthotopic brain GBM models revealed a high dependence of a disrupted BBB for tracer penetrance into tumors. 89Zr-DFO-LEM2/15 showed much higher accumulation in TS543 tumors with a highly disrupted BBB than in U251 orthotopic model in which the BBB permeability was only partially increased. Histological analysis confirmed the specificity of the immunoconjugate in all GBM models. CONCLUSION: A new anti MT1-MMP-mAb tracer, 89Zr-DFO-LEM2/15, was synthesized efficiently. In vivo validation showed high-specific-contrast imaging of MT1-MMP positive GBM tumors and provided strong evidence for utility of MT1-MMP-targeted immunoPET as an alternate to nonspecific imaging of GBM.

GABAA α5 subunit-containing receptors do not contribute to reversal of inflammatory-induced spinal sensitization as indicated by the unique selectivity profile of the GABAA receptor allosteric modulator NS16085.

GABAA receptor positive allosteric modulators (PAMs) mediate robust analgesia in animal models of pathological pain. Restoration of diminished spinal GABAA-α2 and -α3 subunit-containing receptor function is a principal contributor to this analgesia, albeit involvement of GABAA-α5-receptors has not been excluded. Thus, we compared NS11394 and TPA023 (PAMs with selectivity/efficacy at GABAA-α2/α3/α5 receptors) with TP003 (a reportedly GABAA-α3 selective PAM) against spinal sensitization. However, in-house electrophysiology studies designed to confirm the selectivity of TPA023 and TP003 for human GABAA receptors did not corroborate published data, with TP003 displaying considerable GABAA-α5 receptor efficacy. Therefore, we identified a novel PAM, NS16085, which possesses negligible efficacy at GABAA-α5 receptors, but with GABAA-α2/α3 efficacy equivalent to NS11394. At the GABAA-α1 receptor the compound gives low level of negative modulation further separating it from the other compounds. Rat pups with carrageenan-induced hindpaw inflammatory hyperalgesia were used to make ex vivo spinal dorsal root-evoked ventral root recordings. Some spontaneous activity and large numbers of spikes to repetitive stimulation of dorsal roots at C-fibre intensity, indicative of wind-up and sensitization were observed. Equimolar concentrations of NS11394, TP003 and NS16085 all attenuated wind-up to a similar degree; TPA023 was clearly less effective. In adult rats, NS16085 (3-30 mg/kg, p.o.) dose-dependently reduced formalin-induced hindpaw flinching with efficacy comparable to NS11394. Thus, potentiation of GABAA-α2 and-α3 receptors is sufficient to depress spinal sensitization and mediate analgesia after inflammatory injury. Positive modulation at GABAA-α5-receptors is apparently dispensable for this process, an important consideration given the role of this receptor subtype in cognitive function.

The Atlantic-Mediterranean watershed, river basins and glacial history shape the genetic structure of Iberian poplars.

Recent phylogeographic studies have elucidated the effects of Pleistocene glaciations and of Pre-Pleistocene events on populations from glacial refuge areas. This study investigates those effects in riparian trees (Populus spp.), whose particular features may convey enhanced resistance to climate fluctuations. We analysed the phylogeographic structure of 44 white (Populus alba), 13 black (Populus nigra) and two grey (Populus x canescens) poplar populations in the Iberian Peninsula using plastid DNA microsatellites and sequences. We also assessed fine-scale spatial genetic structure and the extent of clonality in four white and one grey poplar populations using nuclear microsatellites and we determined quantitative genetic differentiation (Q(ST) ) for growth traits in white poplar. Black poplar displayed higher regional diversity and lower differentiation than white poplar, reflecting its higher cold-tolerance. The dependence of white poplar on phreatic water was evidenced by strong differentiation between the Atlantic and Mediterranean drainage basins and among river basins, and by weaker isolation by distance within than among river basins. Our results suggest confinement to the lower river courses during glacial periods and moderate interglacial gene exchange along coastlines. In northern Iberian river basins, white poplar had lower diversity, fewer private haplotypes and larger clonal assemblies than in southern basins, indicating a stronger effect of glaciations in the north. Despite strong genetic structure and frequent asexual propagation in white poplar, some growth traits displayed adaptive divergence between drainage and river basins (Q(ST) >F(ST)), highlighting the remarkable capacity of riparian tree populations to adapt to regional environmental conditions.

The Strait of Gibraltar as a major biogeographic barrier in Mediterranean conifers: a comparative phylogeographic survey.

The Strait of Gibraltar (SG) is reputed for being both a bridge and a geographic barrier to biological exchanges between Europe and Africa. Major genetic breaks associated with this strait have been identified in various taxa, but it is unknown whether these disjunctions have been produced simultaneously or by independent biogeographic processes. Here, the genetic structure of five conifers distributed on both sides of the SG was investigated using mitochondrial (nad1 b/c, nad5-1, nad5-4 and nad7-1) and chloroplast (Pt1254, Pt15169, Pt30204, Pt36480, Pt71936 and Pt87268) DNA markers. The distribution of genetic variation was partially congruent between types of markers within the same species. Across taxa, there was a significant overlapping between the SG and the genetic breaks detected, especially for the four Tertiary species surveyed (Abies pinsapo complex, Pinus nigra, Pinus pinaster and Taxus baccata). For most of these taxa, the divergence of populations across the SG could date back to long before the Pleistocene glaciations. However, their strongly different cpDNA G(ST) and R(ST) values point out that they have had dissimilar population histories, which might include contrasting amounts of pollen-driven gene flow since their initial establishment in the region. The fifth species, Pinus halepensis, was genetically depauperated and homogenous on both sides of the SG. A further analysis of nuclear DNA sequences with coalescent-based isolation with migration models suggests a Pleistocene divergence of P. halepensis populations across the SG, which is in sharp contrast with the pre-Pleistocene divergence dates obtained for P. pinaster. Altogether, these results indicate that the genetic breaks observed across this putative biogeographical barrier have been produced by independent evolutionary processes related to the biological history of each individual species instead of a common vicariant phenomenon.

Spatial genetic structure in continuous and fragmented populations of Pinus pinaster Aiton.

Habitat fragmentation, i.e., the reduction of populations into small isolated remnants, is expected to increase spatial genetic structure (SGS) in plant populations through nonrandom mating, lower population densities and potential aggregation of reproductive individuals. We investigated the effects of population size reduction and genetic isolation on SGS in maritime pine (Pinus pinaster Aiton) using a combined experimental and simulation approach. Maritime pine is a wind-pollinated conifer which has a scattered distribution in the Iberian Peninsula as a result of forest fires and habitat fragmentation. Five highly polymorphic nuclear microsatellites were genotyped in a total of 394 individuals from two population pairs from the Iberian Peninsula, formed by one continuous and one fragmented population each. In agreement with predictions, SGS was significant and stronger in fragments (Sp = 0.020 and Sp = 0.026) than in continuous populations, where significant SGS was detected for one population only (Sp = 0.010). Simulations suggested that under fat-tailed dispersal, small population size is a stronger determinant of SGS than genetic isolation, while under normal dispersal, genetic isolation has a stronger effect. SGS was always stronger in real populations than in simulations, except if unrealistically narrow dispersal and/or high variance of reproductive success were modelled (even when accounting for potential overestimation of SGS in real populations as a result of short-distance sampling). This suggests that factors such as nonrandom mating or selection not considered in the simulations were additionally operating on SGS in Iberian maritime pine populations.

[Ankle-brachial index testing is particularly indicated in patients with metabolic syndrome but without known arterial disease]. / La medida del índice tobillo-brazo: particularmente indicada en pacientes con síndrome metabólico sin enfermedad arterial conocida.

INTRODUCTION: The objective was to investigate the prevalence of metabolic syndrome (MetS), its cardiovascular disease (CVD) risk and its association with peripheral arterial disease, defined by a low ankle-brachial index (ABI) (< 0.90), in primary prevention. MATERIAL AND METHODS: Cross-sectional study performed in the primary care general population, aged 50-79 years. CVD risk and ABI were measured in persons without known arterial disease with MetS and in a control group. MetS was defined by Adult Treatment Panel III. CVD risk was estimated using the Systematic Coronary Risk Evaluation (SCORE). RESULTS: A total of 581 subjects were recruited. The prevalence of the metabolic syndrome was 30.8% (95% confidence interval [CI], 27.0-34.5). For the CVD risk and ABI studies 217 individuals were included (138 with MetS and 49 with diabetes). Average CVD risk was high (5%) on patients with MetS and twice as much as those without MetS. ABI was low (< 0.90) on 15 subjects [6.9% (95% CI), 3.5-10.2], with higher frequency in the MetS group: 14 patients (10.1%) vs 1 patient (1.3%). The frequency of low ABI in patients with and without diabetes was 18.3% and 3.6% respectively. Low ABI was associated to MetS, diabetes, inactivity, high risk of SCORE and less alcohol habit. In the multivariate analysis, the odds ratio for the association MetS/low ABI was 14.7 (95% CI, 1.7-123.6). CONCLUSION: MetS is related to asymptomatic peripheral arterial disease. Thus, the measure of ABI in those patients with this syndrome is recommended.

Mating system and pollen gene flow in Mediterranean maritime pine.

Mating systems define the mode of gene transmission across generations, helping to determine the amount and distribution of genetic variation within and among populations of plant species. A hierarchical analysis of Mediterranean maritime pine mating system (61 mother trees from 24 plots, clustered in three populations) was used to identify factors affecting mating patterns and to fit pollen dispersal kernels. Levels of ovule and seed abortion, multi- and single-locus outcrossing rates and correlated paternity were estimated from progeny arrays and correlated with ecological stand variables and biometric tree measures. Pollen dispersal kernels were fitted using TwoGener and KinDist indirect methods and simulations were carried out to identify relevant factors affecting correlated paternity. Maritime pine showed high outcrossing rates (t(m) and t(s) approximately 0.96) and relatively low levels of correlated paternity [an r(p) of 0.018 (Ritland's estimate) or 0.048 (Hardy's estimate)], although higher than in other anemophilous tree species. Mating system parameters had high variation at the single-tree level (99-100%) but no stand or population effect was detected. At the single-tree level, outcrossing rates were correlated with tree (diameter and height) and crown size. In addition, correlated paternity showed a significant negative correlation with tree height, height to crown base and height to the largest crown width, probably reflecting the importance of the trees' 'ecological neighborhoods'. Indirectly estimated pollen dispersal kernels were very leptokurtic (exponential-power distributions with beta<<0.5), with mean dispersal distances from 78.4 to 174.4 m. Fitted dispersal kernels will be useful in building explicit simulation models that include dispersal functions, and which will contribute to current conservation and management programs for maritime pine. Nevertheless, the numerical simulations showed that restricted dispersal, male fertility and phenological overlap could only partially explain the observed levels of correlated paternity; so other factors may also be relevant for the management of this valuable forest tree species.

Fermentation of agro-food wastewaters by activated sludge.

This study investigates the potential of agro-food wastewater fermentation by activated sludge. Experimental results shown that all of the agro-food wastewaters studied initially had considerable concentrations of fermentable substrates, ranging from 19% to 68% of the total COD, but not all of the substrates contained in this COD fraction were fermented after an anaerobic stage of 10h. The percentage of fermentable substrates fermented by the activated sludge during the anaerobic stage ranged from 14% to 68%, presenting the potato processing wastewater the highest concentration of fermented substrates. A mathematical model was proposed to describe the fermentation process. By using this model, the maximum fermentation rates were obtained, ranging their values from 0.6 to 3.4 (gCODgCOD(-1)d(-1)). The fermentation potentials of the agro-food wastewaters were also determined, their values ranged from 0.17 to 0.20 (gCODgCOD(-1)) except for the cheese and the winery wastewater which presented fermentation potentials of 0.12 and 0.14 (gCODgCOD(-1)), respectively.

Cineantropometría: Composición corporal y somatotipo de futbolistas que desarrollan su actividad física en equipos de la Comunidad Autónoma de Madrid / Kinanthropometry: Body composition and somatotype of football players whose physical activity is performed in teams of the Autonomous Region of Madrid

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Denitrification potential of industrial wastewaters.

Nitrate utilisation batch experiments have been carried out with different agro-food industrial wastewaters. The results obtained were modelled using a modification of the ASM2d to determine the main kinetic and stoichiometric parameters: denitrification rate with fermentation products (q(N-SA)) and with fermentable substrates (q(N-SF)); fermentation products and fermentable substrates consumption rates, (qSA) and (qSF), respectively; yield coefficient with fermentation products (Y(H-SA)) and with fermentable substrates (Y(H-SF)) and saturation coefficient for growth on fermentation products (K(H-SA)). It was found that fermentation products (SA) and fermentable substrates (SF) consumption rates can be assumed to be both constant and independent of the agro-food industrial wastewater used, with values of 14.6 and 5.4 (mg S(COD) g COD-X(-1)OHO h(-1)), respectively. The mean denitrification rates obtained with each agro-food industrial wastewater ranged from 1.5 to 2.5 (mg S(N) g COD-X(-1)OHO h(-1)), values slightly lower to the obtained with domestic wastewater (2.7 mg S(N) g COD-X(-1)OHO h(-1)). Given the substrate consumption rate and the denitrification rate, the yields with fermentation products and fermentable substrates for each wastewater were determined. The values obtained for the yields ranged from 0.50 to 0.69 on using SA and from 0.50 to 0.70 on using SF. Having determined these parameters, the denitrification potential (DNP) was evaluated for each agro-food wastewater. Wastewater from slaughterhouses gave the lowest DNP (22.6 mg S(N) g S(-1)COD), whereas wastewater from potato and tomato processing plants gave the highest values (126.5 and 128.2 mg S(N) g S(-1)COD), respectively), which are very similar to that obtained with domestic wastewater (130.3 and 128.2 mg S(N) g S(-1)COD). Taking into account the low N/COD ratio presented in the agro-food wastewaters, the last wastewaters are the most indicated to enhance the nitrogen removal in the WWTP. Finally, a relationship between the denitrification rates of several agro-food industrial wastewaters and their respective S(A)/(S(A) + S(F)) ratio was obtained. This relationship can be used to estimate the mean denitrification rate of an agro-food industrial wastewater.

Simulation of atmospheric PAH emissions from diesel engines.

Simulation of atmospheric PAH emissions in a typical European passenger car diesel engine at steady conditions or under a certification cycle is made using in-house software. It is based on neural fitting of experimental data from eight different fuels tested under five operating steady conditions (reproducing modes of the European transient urban/extraurban certification cycle). The software allows the determination of PAH emissions as a function of the fuel composition parameters (aromatic content, cetane index, gross heat power, nitrogen and sulphur content) and operation conditions (torque and engine speed). The mathematical model reproduces experimental data with a maximum error of 20%. This tool is very useful, since changes in parameters can be made without experimental cost and the trend in modifications in PAH emissions is immediately obvious.

Características del dolor crónico en el anciano: tratamiento / Characteristics of chronic pain among the elderly: management

Chronic pain is a worldwide problem that has a particular significance, prevalence and relevance among the elderly, since it is associated to chronic diseases that incre ase with age. Pain is suffered by 50-80 por ciento of the population older than 65. Chronic pain, also in the elderly, becomes a tiring experience linked to a psychological suffering associated to anxiety and depression that determines and increases pain perception. Despite the above, a high perc e n t age of patients do not receive an appropriate tre a t m e n t . Management of chronic pain among the elderly is based on the WHO analgesic scale: NSAIs, opiates, coadjuvant drugs (antidepressants, anticonvulsants...) and psychological support, the latter being very important, since pain and d e p ression are symptoms frequently associated and overlapped, thus being very difficult to differentiate between both symptoms, and determining not only the type of treatment, but also its outcomes El dolor crónico es un problema universal que tiene especial importancia y prevalencia en el anciano ya que se asocia a enfermedades crónicas que aumentan con la edad. En t re un 50-80 por ciento de la población mayor de 65 años pre s e nta dolor. El dolor crónico, también en el anciano, es una experiencia agotadora, unida a un sufrimiento psicológico con síntomas de ansiedad y depresión que condicionan y aumentan la percepción dolorosa. A pesar de ello un gran núm e ro de pacientes, no recibe el tratamiento adecuado. El tratamiento del dolor crónico en el anciano se basa en la escalera analgésica de la OMS: AINEs, opiáceos, medicación coadyuvante (antidepresivos, anticonvulsivantes, etc.) y apoyo psicológico, punto este muy importante puesto que el dolor y depresión son síntomas que se asocian y se solapan con gran frecuencia, siendo muy difícil diferenciar un síntoma de otro, condicionando no sólo el tipo de tratamiento sino también sus resultados (AU)

Mass spectra of new substituted 2-amino-4H-pyrans: a retro-Diels-Alder reaction pattern.

New substituted 2-amino-3-cyano-4H-pyrans have been studied by electron ionization (EI), chemical ionization (CI) and electrospray ionization (ESI) mass spectrometry. The retro-Diels-Alder reaction (RDA) is the main fragmentation pattern observed in the EI spectra forming an unsaturated ketone as the diene fragment. In contrast, a different RDA reaction takes place yielding an unsaturated amide as diene fragment together with the unsaturated ketone in the CI spectra. The MS/MS spectra obtained using an ESI source reveal that the favoured fragmentation by collision induced dissociation (CID) is the elimination of the substituent at the C4 position with formation of a stable pyrilium cation.