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Tumor growth depends on the vascular system, either through the expansion of blood vessels or novel adaptation by tumor cells. One of these novel pathways is vasculogenic mimicry (VM), which is defined as a tumor-provided vascular system apart from endothelial cell-lined vessels, and its origin is partly unknown. It involves highly aggressive tumor cells expressing endothelial cell markers that line the tumor irrigation. VM has been correlated with high tumor grade, cancer cell invasion, cancer cell metastasis, and reduced survival of cancer patients. In this review, we summarize the most relevant studies in the field of angiogenesis and cover the various aspects and functionality of aberrant angiogenesis by tumor cells. We also discuss the intracellular signaling mechanisms involved in the abnormal presence of VE-cadherin (CDH5) and its role in VM formation. Finally, we present the implications for the paradigm of tumor angiogenesis and how targeted therapy and individualized studies can be applied in scientific analysis and clinical settings.

Lyme carditis is an extracutaneous manifestation of Lyme disease characterized by episodes of atrioventricular block of varying degrees and additional, less reported cardiomyopathies. The molecular changes associated with the response to Borrelia burgdorferi over the course of infection are poorly understood. Here, we identify broad transcriptomic and proteomic changes in the heart during infection that reveal a profound down-regulation of mitochondrial components. We also describe the long-term functional modulation of macrophages exposed to live bacteria, characterized by an augmented glycolytic output, increased spirochetal binding and internalization, and reduced inflammatory responses. In vitro, glycolysis inhibition reduces the production of tumor necrosis factor (TNF) by memory macrophages, whereas in vivo, it produces the reversion of the memory phenotype, the recovery of tissue mitochondrial components, and decreased inflammation and spirochetal burdens. These results show that B. burgdorferi induces long-term, memory-like responses in macrophages with tissue-wide consequences that are amenable to be manipulated in vivo.

Supplemental material that contains; - method for the characterization of valvular endothelial cells by immunostaining. - Supplemental Figure S1. Characterization of aortic valve endothelial cells. - Supplemental Figure S2. Cell counting corresponding to Fig 7 of the manuscript. - Supplemental Table S1. Clinical features of patients used in the study of mixed VEC population. - Supplemental Table S2. Clinical characteristics of patients used in the study of aortic- and ventricular-sided endothelial cells.

The human Alzheimer’s disease (AD) brain accumulates angiogenic markers but paradoxically, the cerebral microvasculature is reduced around Aß plaques. Here we demonstrate that angiogenesis is started near Aß plaques in both AD mouse models and human AD samples. However, endothelial cells express the molecular signature of non-productive angiogenesis (NPA) and accumulate, around Aß plaques, a tip cell marker and IB4 reactive vascular anomalies with reduced NOTCH activity. Notably, NPA induction by endothelial loss of presenilin, whose mutations cause familial AD and which activity has been shown to decrease with age, produced a similar vascular phenotype in the absence of Aß pathology. We also show that Aß plaque-associated NPA locally disassembles blood vessels, leaving behind vascular scars, and that microglial phagocytosis contributes to the local loss of endothelial cells. These results define the role of NPA and microglia in local blood vessel disassembly and highlight the vascular component of presenilin loss of function in AD.

The local conditions of tumor cell growth, known as the tumor microenvironment (TME), are characterized by low oxygen supply (hypoxia) caused by insufficient blood delivery. Hypoxia cancers have a strong invasive potential, metastasis, resistance to therapy and a poor clinical prognosis. The key regulator of adaptation to tumor hypoxia is hypoxia inducible factor 1-¿ (HIF-1¿). Despite its significance, the underlying transformations that cause this highly aggressive behaviour are poorly understood, specific pharmacological inhibition of HIF-1¿ activation in the tumor are not available. Our group has shown that PARP inhibitors can modulate HIF-1¿ levels and its activation. On the other hand, hyperoxia could be a treatment of medical interest to fight tumors that present with hypoxia; nevertheless, its use may involve clinically unacceptable lung damage. AIMS: In this study, we aim to demonstrate that the use of PARP inhibitors (1) will interfere with the adaptation of the tumor to the hypoxic microenvironment (which is recreated with the hypoxia-mimetic,CoCl2), in combination with the use with oxygen to induce hyperoxia and (2) will decrease the lung damage induced by reactive oxygen species. Therefore, the combined use of oxygen and PARP inhibitors in metastatic melanoma (expressing high levels of HIF-1) could delay metastasis and improve the efficacy of anti-tumor therapy.

Addressing the problem of infection from the very first stage, i.e. inhibiting the formation of the bacterial biofilm, is a crucial step to prevent implant rejection. Nanocolumnar coatings exhibiting antibacterial properties have been fabricated by oblique deposition with magnetron sputtering [1]. The formation of nanocolumns (Fig.1) is the result of the effects of atomic shadowing when the atoms reach the surface along an inclined direction [2]. This technique is environmentally friendly: it is carried out at RT and does not involve chemical products (no recycling problems). Such methodology have been tested in a semiindustrial scale reactor, successfully coating in a single step the two sides of fixation plates for bone fractures [3]. Several in vitro experiments have been performed: analysis of bacterial adhesion and biofilm formation, analysis of osteoblast proliferation and mitochondrial activity, and osteoblasts–bacteria competitive growth scenarios, the latter also named “Race for the Surface” competition. In all these cases, the coatings show an opposite behavior toward osteoblast and bacterial proliferation [1,3]. Moreover, they are effective against Gram positive (S. aureus) and Gram negative (E. coli) bacteria [4]. Finally, when a synergic route is followed and the coatings are functionalized with Te nanorods, the antibacterial properties are enhanced, since Te adds contact-killing (Fig. 2), i.e. bactericidal effect, whilst the biocompatibility is preserved [4].

All metazoans depend on the consumption of O2 by the mitochondrial oxidative phosphorylation system (OXPHOS) to produce energy. In addition, the OXPHOS uses O2 to produce reactive oxygen species that can drive cell adaptations1,2,3,4, a phenomenon that occurs in hypoxia4,5,6,7,8 and whose precise mechanism remains unknown. Ca2+ is the best known ion that acts as a second messenger9, yet the role ascribed to Na+ is to serve as a mere mediator of membrane potential10. Here we show that Na+ acts as a second messenger that regulates OXPHOS function and the production of reactive oxygen species by modulating the fluidity of the inner mitochondrial membrane. A conformational shift in mitochondrial complex I during acute hypoxia11 drives acidification of the matrix and the release of free Ca2+ from calcium phosphate (CaP) precipitates. The concomitant activation of the mitochondrial Na+/Ca2+ exchanger promotes the import of Na+ into the matrix. Na+ interacts with phospholipids, reducing inner mitochondrial membrane fluidity and the mobility of free ubiquinone between complex II and complex III, but not inside supercomplexes. As a consequence, superoxide is produced at complex III. The inhibition of Na+ import through the Na+/Ca2+ exchanger is sufficient to block this pathway, preventing adaptation to hypoxia. These results reveal that Na+ controls OXPHOS function and redox signalling through an unexpected interaction with phospholipids, with profound consequences for cellular metabolism.

Aberrant extra-vascular expression of VE-cadherin has been observed in metastasis associated with Vasculogenic Mimicry (VM); we have recently shown that in VM prone cells VE-cadherin is mainly in the form of phospho-VE-cadherin in Y658 allowing increased plasticity that potentiates VM development in malignant cells. In the current study, we present results to show that human malignant melanoma cells VM+, express the VE-cadherin phosphatase VE-PTP. VE-PTP forms a complex with VE-Cadherin and p120-catenin and the presence of this complex act as a safeguard to prevent VE-Cadherin protein degradation by autophagy. Indeed, VE-PTP silencing results in complete degradation of VE-cadherin with the features of autophagy. In summary, this study shows that VE-PTP is involved in VM formation and disruption of VE-PTP/VE-Cadherin/p120 complex results in enhanced autophagy in aggressive VM cells. Thus, we identify VE-PTP as a key player in VM development by regulating VE-cadherin protein degradation through autophagy.

In this paper, we summarize published articles and experiences related to the attempt to improve radiotherapy outcomes and, thus, to personalize the radiation treatment according to the individual characteristics of each patient. The evolution of ideas and the study of successively published data have led us to envisage new biophysical models for the interpretation of tumor and healthy normal tissue response to radiation. In the development of the model, we have shown that when mesenchymal stem cells (MSCs) and radiotherapy are administered simultaneously in experimental radiotherapy on xenotumors implanted in a murine model, the results of the treatment show the existence of a synergic mechanism that is able to enhance the local and systemic actions of the radiation both on the treated tumor and on its possible metastasis. We are convinced that, due to the physical hallmarks that characterize the neoplastic tissues, the physical-chemical tropism of MSCs, and the widespread functions of macromolecules, proteins, and exosomes released from activated MSCs, the combination of radiotherapy plus MSCs used intratumorally has the effect of counteracting the pro-tumorigenic and pro-metastatic signals that contribute to the growth, spread, and resistance of the tumor cells. Therefore, we have concluded that MSCs are appropriate for therapeutic use in a clinical trial for rectal cancer combined with radiotherapy, which we are going to start in the near future.

Poly(ADP-ribose) polymerases (PARPs), represent a family of 17 proteins implicated in a variety of cell functions; some of them possess the enzymatic ability to synthesize and attach poly (ADP-ribose) (also known as PAR) to different protein substrates by a post-translational modification; PARPs are key components in the cellular response to stress with consequences for different physiological and pathological events, especially during neoplasia. In recent years, using PARP inhibitors as antitumor agents has raised new challenges in understanding their role in tumor biology. Notably, the function of PARPs and PAR in the dynamic of tumor microenvironment is only starting to be understood. In this review, we summarized the conclusions arising from recent studies on the interaction between PARPs, PAR and key features of tumor microenvironment such as hypoxia, autophagy, tumor initiating cells, angiogenesis and cancer-associated immune response.

Orthopedic metal implants improve the quality of life of millions of patients each year. The main problem they present is infection, which depending on the type of device and the patient's health affects 0.5-5% of cases. Our approach to this problem is to use nanostructured coatings to reduce the risk of infection. In short, by magnetron sputtering at oblique incidence [1] we fabricate a coating formed by titanium nanocolumns that develop as the result of atomic shadowing processes in the ballistic deposition regime, see Figure. It is an energy efficient method that can be scaled-up to industry, since it takes place at room temperature in one single step and no chemicals are involved (thus without recycling problems).

Based on an already tested laboratory procedure, a new magnetron sputtering methodology to simultaneously coat two-sides of large area implants (up to ~15 cm2) with Ti nanocolumns in industrial reactors has been developed. By analyzing the required growth conditions in a laboratory setup, a new geometry and methodology have been proposed and tested in a semi-industrial scale reactor. A bone plate (DePuy Synthes) and a pseudo-rectangular bone plate extracted from a patient were coated following the new methodology, obtaining that their osteoblast proliferation efficiency and antibacterial functionality were equivalent to the coatings grown in the laboratory reactor on small areas. In particular, two kinds of experiments were performed: Analysis of bacterial adhesion and biofilm formation, and osteoblasts–bacteria competitive in vitro growth scenarios. In all these cases, the coatings show an opposite behavior toward osteoblast and bacterial proliferation, demonstrating that the proposed methodology represents a valid approach for industrial production and practical application of nanostructured titanium coatings.

Amino-terminated oligoglycine two-dimensional (2D) peptide self-assemblies (known as tectomers) have a versatile surface chemistry that allows them to interact with a variety of nanomaterials and to actas supramolecular adhesives for surface functionalization. Here, we have exploited the strong hydrogen-bond based interaction between tectomers and graphene oxide (GO) to functionalize GO fiber surfaces with different carbon nanomaterials (carbon nanotubes, carbon nanohorns, carbon nanocones, and highly fluorescent nanodiamonds), metal (gold, platinum, iron) nanoparticles, acrylate-based polymernanoparticles, fluorophores and drugs. The resulting ultrathin coatings exhibit remarkable water resis-tant properties. This tectomer-mediated fiber decoration strategy allows coating functionalities to be tailored by choosing the appropriate nanomaterials or other molecules. We show that this strategy can be extended to other fibers and fabrics, such as polyurethane/PEDOT:PSS, poly(methyl methacrylate) and polyester, making it very attractive for a variety of technological and smart textile applications.

Komagataeibacter medellinensis ID13488 (formerly Gluconacetobacter medellinensis ID13488) is able to produce crystalline bacterial cellulose (BC) under high acidic growth conditions. These abilities make this strain desirable for industrial BC production from acidic residues (e.g. wastes generated from cider production). To explore the molecular bases of the BC biosynthesis in this bacterium, the genome has been sequenced revealing a sequence of 3.4 Mb containing three putative plasmids of 38.1 kb (pKM01), 4.3 kb (pKM02) and 3.3 Kb (pKM03). Genome comparison analyses of K. medellinensis ID13488 with other cellulose-producing related strains resulted in the identification of the bcs genes involved in the cellulose biosynthesis. Genes arrangement and composition of four bcs clusters (bcs1, bcs2, bcs3 and bcs4) was studied by RT-PCR, and their organization in four operons transcribed as four independent polycistronic mRNAs was determined. qRT-PCR experiments demonstrated that mostly bcs1 and bcs4 are expressed under BC production conditions, suggesting that these operons direct the synthesis of BC. Genomic differences with the close related strain K. medellinensis NBRC 3288 unable to produce BC were also described and discussed.

The development of devices for sensing and monitoring CO2 levels is crucial for many fields such as food packaging and for human safety indoors. Herein the fabrication of an optical CO2 sensor by integration of a metal–organic framework (MOF) onto bimodal optical waveguides is reported. This sensor is constructed via self-assembly of a transparent film of zeolitic imidazolate framework-8 (ZIF-8) nanoparticles (size: 32 ± 5 nm) on the waveguides. The nanoZIF-8-based sensor exhibits a broad linear response, with limits of detection of 3130 ppm at room temperature and 774 ppm at 278 K. Furthermore, it is robust, selective, fast and reusable, and can be stored under humid conditions with no loss in performance.

High-risk hematological malignancies are a privileged setting for infection by opportunistic microbes, with invasive mycosis being one of the most serious complications. Recently, genetic background has emerged as an unanticipated risk factor. For this reason, polymorphisms for genes encoding archetypal receptors involved in the opsonic and nonopsonic clearance of microbes, pentraxin-3 (PTX3) and Dectin-1, respectively, were studied and correlated with the risk of infection. Fungal, bacterial, and viral infections were registered for a group of 198 patients with high-risk hematological malignancies. Polymorphisms for the pentraxin-3 gene (PTX3) showed a significant association with the risk of fungal infection by Candida spp. and, especially, by Aspergillus spp. This link remained even for patients undergoing antifungal prophylaxis, thus demonstrating the clinical relevance of PTX3 in the defense against fungi. CLEC7A polymorphisms did not show any definite correlation with the risk of invasive mycosis, nor did they influence the expression of Dectin-1 isoforms generated by alternative splicing. The PTX3 mRNA expression level was significantly lower in samples from healthy volunteers who showed these polymorphisms, although no differences were observed in the extents of induction elicited by bacterial lipopolysaccharide and heat-killed Candida albicans, thus suggesting that the expression of PTX3 at the start of infection may influence the clinical outcome. PTX3 mRNA expression can be a good biomarker to establish proper antifungal prophylaxis in immunodepressed patients.

Growing evidence suggests a close relationship between Alzheimer's Disease (AD) and cerebral hypoxia. Astrocytes play a key role in brain homeostasis and disease states, while some of the earliest changes in AD occur in astrocytes. We have therefore investigated whether mutations associated with AD increase astrocyte vulnerability to ischemia. Two astroglioma cell lines derived from APPSWE /PS1A246E (APP, amyloid precursor protein; PS1, presenilin 1) transgenic mice and controls from normal mice were subjected to oxygen and glucose deprivation (OGD), an in vitro model of ischemia. Cell death was increased in the APPSWE /PS1A246E line compared to the control. Increasing extracellular calcium concentration ([Ca2+ ]) exacerbated cell death in the mutant but not in the control cells. In order to explore cellular Ca2+ homeostasis, the cells were challenged with ATP or thapsigargin and [Ca2+ ] was measured by fluorescence microscopy. Changes in cytosolic Ca2+ concentration ([Ca2+ ]c ) were potentiated in the APPSWE /PS1A246E transgenic line. Mitochondrial function was also altered in the APPSWE /PS1A246E astroglioma cells; mitochondrial membrane potential and production of reactive oxygen species were increased, while mitochondrial basal respiratory rate and ATP production were decreased compared to control astroglioma cells. These results suggest that AD mutations in astrocytes make them more sensitive to ischemia; Ca2+ dysregulation and mitochondrial dysfunction may contribute to this increased vulnerability. Our results also highlight the role of astrocyte dyshomeostasis in the pathophysiology of neurodegenerative brain disorders.

The glancing angle deposition technique by magnetron sputtering is a scalable technique that allows the production of nanostructured coatings in large areas [1]. In recent works, we have shown that nanocolumnar coatings made of Ti were successfully prepared with this method [2] and how they exhibited selective behavior towards osteoblast and Staphylococcus aureus (S. a.) proliferation [3]: the biocompatibility towards human cells was preserved, whilst the adherence and proliferation of S. a. were dramatically reduced, not only with commercial strains but also with clinical ones coming from infected patients. In this new work, not only Gram-positive bacteria but also Gram-negative ones (E. Coli) have been used to test the response of different coatings fabricated in two set-ups, one of them being a semi-industrial equipment, in order to check the robustness of this approach. Moreover, Te nanorods were synthesized on top of the nanocolumns (see Fig.) using a hydrothermal and environmentally-friendly approach. It will be shown that the antibacterial behavior is enhanced when this synergic route combining Ti nanocolumns and Te nanorods is used, especially in the case of long nanocolumns. Furthermore, all the coatings remain biocompatible for human cells and allow for their proliferation.

Here we present a route for non-covalent functionalization of carboxylated multi-walled carbon nanotubes and graphene oxide with novel two-dimensional peptide assemblies. We show that self-assembled amino-terminated biantennary and tetraantennary oligoglycine peptides (referred to as tectomers) effectively coat carboxylated multi-walled carbon nanotubes and also strongly interact with graphene oxide due to electrostatic interactions and hydrogen bonding as the driving force, respectively. The resulting hybrids can be made into free-standing conducting composites or applied in the form of thin, pH-switchable bioadhesive coatings onto graphene oxide fibers. Monitoring of cell viability of pancreatic cell lines, seeded on those CNT hybrids, show that they can be used as two- and three-dimensional scaffolds to tissue engineer tumour models for studying ex vivo the tumour development and response to treatment. This highly versatile method in producing pH-responsive hybrids and coatings offers an attractive platform for a variety of biomedical applications and for the development of functional materials such as smart textiles, sensors and bioelectronic devices.

A low-cost approach to fabricate nanostructured coatings will be presented: oblique deposition with sputtering. This technique is energetically efficient and environmentally friendly, since it takes place at room tem perature in one single step and no chemicals are involved (thus without recycling problems). Any kind of flat substrate can be used, and with feasible modifications, it can be scaled up to large surfaces. The growth regimes [1-3] and the deposition rate [4] of the nanostructured coatings obtained using two different materials, gold and titanium, will be discussed. It will be shown that the formation of nanostructures is the outcome of self-shadowing effects when vapor species arrive at the film surface along a tilted direction (see Figure). In fact, we have developed a fundamental framework to explain the different morphologies obtained, the key factor being the thermalization degree of sputtered particles that accounts for the collisional processes in the vapor phase between the travelling atoms and the plasma species. In particular, at low pressures, tilted nanocolumns can be obtained when the angle of incidence surpasses a critical threshold. Moreover, if substrate rotation is used, the majority of nanostr uctures becomes axially symmetric. Several applications of such nanocolumnar coatings will be reviewed, especially focusing in two of them: black metals [5] and antibacterial coatings [6].

Mitochondria use oxygen as the final acceptor of the respiratory chain, but its incomplete reduction can also produce reactive oxygen species (ROS), especially superoxide. Acute hypoxia produces a superoxide burst in different cell types, but the triggering mechanism is still unknown. Herein, we show that complex I is involved in this superoxide burst under acute hypoxia in endothelial cells. We have also studied the possible mechanisms by which complex I could be involved in this burst, discarding reverse electron transport in complex I and the implication of PTEN-induced putative kinase 1 (PINK1). We show that complex I transition from the active to ‘deactive’ form is enhanced by acute hypoxia in endothelial cells and brain tissue, and we suggest that it can trigger ROS production through its Na/H antiporter activity. These results highlight the role of complex I as a key actor in redox signalling in acute hypoxia.

In this study, the effects of calcination and milling of 8YSZ (8 mol% yttria stabilized zirconia) used in the nickel-YSZ anode on the performance of anode supported tubular fuel cells were investigated. For this purpose, two different types of cells were prepared based on a Ni-YSZ/YSZ/NdNiO-YSZ configuration. For the anode preparation, a suspension was prepared by mixing NiO and YSZ in a ratio of 65:35 wt% (Ni:YSZ 50:50 vol.%) with 30 vol.% graphite as the pore former. As received Tosoh YSZ or its calcined form (heated at 1500 °C for 3 hours) was used in the anode support as the YSZ source. Electrochemical results showed that optimization of the fuel electrode microstructure is essential for the optimal distribution of gas within the support of the cell, especially under electrolysis operation where the performance for an optimized cell (calcined YSZ) was enhanced by a factor of two. In comparison with a standard cell (containing as received YSZ), at 1.5 V and 800 °C the measured current density was -1380 mA cm and -690 mA cm for the cells containing calcined and as received YSZ, respectively. The present study suggests that the anode porosity for improved cell performance under SOEC is more critical than SOFC mode due to more complex gas diffusion under electrolysis mode where large amount of steam needs to be transfered into the cell.

The growth of Ti thin films by the magnetron sputtering technique at oblique angles and at room temperature is analysed from both experimental and theoretical points of view. Unlike other materials deposited in similar conditions, the nanostructure development of the Ti layers exhibits an anomalous behaviour when varying both the angle of incidence of the deposition flux and the deposition pressure. At low pressures, a sharp transition from compact to isolated, vertically aligned, nanocolumns is obtained when the angle of incidence surpasses a critical threshold. Remarkably, this transition also occurs when solely increasing the deposition pressure under certain conditions. By the characterization of the Ti layers, the realization of fundamental experiments and the use of a simple growth model, we demonstrate that surface mobilization processes associated to a highly directed momentum distribution and the relatively high kinetic energy of sputtered atoms are responsible for this behaviour

This report describes a simple strategy to produce copolymers of tetrahydrofuran (THF) and glycidyl phenyl ether (GPE) by using B(C6F5)3 as a catalyst. The control of the synthesis conditions, such as reaction time, catalyst concentration, and monomer concentration, allows the formation of copolymers with molecular weights in the range of 15-330 kg/mol. MALDI-TOF mass spectrometry revealed that with a low THF content in the feed cyclic copolymers are the major reaction products, whereas with a high THF content, linear copolymers are the main products. To explain these results, a zwitterionic ring-opening copolymerization mechanism was postulated based on DFT calculations and experimental results. Physical properties of the resulting copolymers demonstrated that by changing the relative amounts of monomers copolymers with tailored glass transition temperatures in a broad range of temperatures from-84 to-4 °C can be obtained and that crystallization of THF fragments can be suppressed. Rheological measurements showed that by controlling the degree of crystallization, copolymers with rubber-like behavior can be obtained in a broad temperature range below room temperature.

Zwitterionic ring-opening polymerization is used as a strategy to covalently anchor polyethers of different chemical nature and polarity onto thermally reduced graphene oxide (rGO) sheets. This versatile strategy involves the generation of a macrozwitterionic propagating species by reaction of a functional epoxide monomer with a Lewis acid catalyst, B(CF). Upon addition of rGO sheets, the polyether propagating species react with available nucleophilic groups on the rGO surface to generate graphene sheets decorated with functional polyether chains in amounts as large as 30 wt%. Polyethers obtained from glycidyl monomers carrying hydroxyl, hexadecyl and fluorinated groups, as well as a copolyether of tetrahydrofuran and glycidyl phenyl ether, were successfully grafted to rGO sheets. Surprisingly, grafting was found to increase the degree of hydrophilicity of the rGO sheets, irrespective of the hydrophobic or hydrophilic character of the side groups attached to the main polyether chain, as determined from contact angle measurements in both macroscopic and microscopic experiments. Properties such as the degree of crystallization of poly(tetrahydrofuran) grafted onto rGO sheets and the transparency of polymer films containing polyether-grafted rGO sheets were also evaluated in this study.

Remarkable progress in the fabrication of carbon nanotube composite fibers has resulted through the development of the wet-spinning technique pioneered by Vigolo et al. [1] This process implies the fabrication of gel fibers as a result of the collapse of surfactant-stabilized carbon nanotube dispersions when injected into a coagulation bath. When dried, those gel fibers become solid fibers with high carbon nanotube contents (³ 50 wt.%), significantly higher than those achieved by other fiber spinning technologies, such as melt-spinning or electrospinning. We here report how this wet-spinning method provides carbon nanotube composite fibers with tunable properties, which mainly depend on the composition of the coagulation bath used. Polymers including polyvinyl alcohol (PVA) [2-5] and polyethylenimine (PEI) [6] have been here investigated as coagulants.[7] Remarkable transport-, supercapacitor- and electrochemical actuation properties are demonstrated for these coagulation wet-spun fibers, that can be woven into fabrics and therefore offer promise for a variety of electronic textile applications [2-4].

Carbon nanofibers (CNFs) were modified with B and P by an ex-situ approach. In addition, CNFs doped with nitrogen were prepared in-situ using ethylenediamine as N and C source. After calcination, the doped CNFs were used as catalyst for the oxidative dehydrogenation of propane. For B-doped CNFs, the effects of boron loading and calcination temperature on boron speciation and catalytic conversion were studied. For the same reaction temperatures and conversions, B and P doped CNFs exhibited higher selectivities to propene than pristine CNFs. The N-doped CNFs were the most active but the least selective. Our results also show that the type of phosphorous precursor affects the selectivity to propene and that CNFs modified using triphenylphosphine as precursor exhibited the highest selectivity at isoconversion.

La ablación láser es ampliamente utilizada para la obtención de recubrimientos mediante la irradiación de un blanco y la posterior deposición del material ablacionado sobre substratos apropiados, lo que se conoce como Deposición por Láser Pulsado (PLD). También se utiliza para la modificación directa de superficies (Ablación por Láser Pulsado o PLA). Aunque existe mucha literatura relacionada con ambas técnicas, no existe un criterio unificado para este procesado que permita reproducir los parámetros láser experimentales convenientemente, especialmente cuando se utilizan láseres con diferentes características de emisión. En este trabajo, se han irradiado superficies metálicas con láseres pulsados en atmósferas reactivas y no reactivas. Se han estudiado los parámetros de barrido, los modos de emisión láser y la longitud de onda y se han relacionado con los espesores obtenidos o afectados, la zona afectada por calor (ZAC) y la química que tiene lugar en la superficie del substrato. Se ha utilizado microscopia confocal y microscopia de barrido de emisión de campo para estudiar la microestructura y la composición química de las superficies modificadas. Este trabajo pretende discernir si la irradiación láser es un parámetro unificador para los procesos de PLA que permita establecer correlaciones entre las propiedades del materiales y otros parámetros de procesado.

Capillary electrophoresis (CE) coupled with laser-induced fluorescence detection (LIF) has allowed to obtain protein fingerprints, which have demonstrated to be useful in microorganisms characterization. In this work, protein fingerprints of two species of Staphylococcus grown in different culture media and submitted to temperature and nitrosative stress were studied by CE-LIF. After the growth of the bacteria, protein extracts were obtained by cell lysis using sonication. The water-soluble fraction of these lysates was derivatized on-capillary with a fluorogenic dye, 3-(2-furoyl)quinoline-2-carboxaldehyde. The fluorescent products were analyzed by CE using phosphate buffer containing submicellar concentrations of sodium pentanesulfate and detected by LIF. Different protein fingerprints were obtained depending on the bacterial specie studied, indicating the usefulness of this method for the identification of different species of the same bacterial genus. It was also demonstrated that the CE protein fingerprints were dependent on the culture conditions, such as growth medium, or on stressing conditions, such as heat shock or nitrosative stress

Gas transport of carbon dioxide in poly[bisphenol A carbonate-co-4,4¢-(3,3,5-trimethylcyclohexylidene)diphenol carbonate] films over a wide range of pressure is described. The interpretation of the experimental results in terms of the dual mode model allowed the evaluation of the parameters of the model that govern the gas permeation process. The value of the diffusion coefficient obtained for carbon dioxide at zero concentration was 2.4 10-8 cm2 s-1, at 303 K. This parameter was also measured by using pulsed field gradient NMR finding that its value reaches a nearly constant value of (2.7 ( 0.9) 10-8 cm2 s-1, at 298 K, for diffusion times greater than 20 ms. Both the diffusion and solubility coefficients were also computed by using simulation methods based on the transition states theory and the Widom method, respectively. The value obtained for the diffusion coefficient was 1.8 10-8 cm2 s-1, at 303 K, which compares very favorably with the experimental measurements. The drop of the simulated solubility coefficient with increasing pressure is sharper than that of the experimental one, at low pressures, and similar, at high pressures.

The electronic structure of the recently isolated silver copper oxide Ag2Cu2O4 is analyzed along with its precursor Ag2Cu2O3 and similar binary oxides, Ag 2O, AgO, CuO, and NaCuO2, using X-ray photoemission (XPS) and X-ray absorption (XAS) measurements. The results for Ag2Cu 2O4 reveal an electronic distribution in which silver and copper share a delocalized valence scheme with both metals in formal oxidation states larger than the usual AgI and CuII. Only one type of crystallographic silver or copper is found, but disorder strain parameters are considerable and the possibilities of thermal disorder, atomic motion, oxygen contribution, mixed valence, and internal charge delocalization are considered. Classical coordination descriptions for oxidized silver are revisited in terms of this new internal charge delocalization framework found for the electronic structure.

Integration into a conducting polymer matrix to form a hybrid material is an effective way to harness the electrochemical activity of nanosized oxide clusters. By anchoring them into polyaniline, the reversible redox chemistry of the otherwise soluble polyoxometalate clusters can be combined with that of the conducting polymer and be put to work in energy storage applications. We present here preliminary results that show how the resulting hybrid polymer displays the combined activity of its organic and inorganic components to store and release charge in a solid state electrochemical capacitor device.

The structure of Ag2Cu2O4 synthesized by electrochemical oxidation of its precursor Ag2Cu2O3 is studied under a new perspective. Irradiation of the oxide with X-ray beam transforms the electronic structure of the phase by redistributing the internal charge within the material. The refined structure shows several possibilities all with metals in the same arrangement, but with oxygen atoms distributed in a rather disordered way. This is typical of ionic conductors.

Electrochemical oxidation at room temperature of a slurry of Ag2Cu2O3 yields a new silver copper oxide, formulated as Ag2Cu2O4, with one more atom of oxygen per unit formula, that can in turn revert to the original precursor. The resulting oxide presents a different electronic and crystal structure from its precursor, as shown by XPS, X-ray and electron diffraction. This phase transformation involves a radical structural change from a 3D to a 2D network, as well as electronic changes involving silver and oxygen. The potential of electrochemical techniques to induce crystal-chemical solid state transformations is analyzed.

We have studied by incoherent quasielastic neutron scattering the molecular dynamics of the ferroelectric copolymers of vinylidene fluoride and trifluoroethylene with two different molar ratios. Thermal hysteresis effects accompanying the structural changes observed in these materials are found. In the temperature range investigated three motions were identified: (i) a vibrational motion of Debye-Waller type which shows increasing amplitude until the vicinity of the Curie temperature and then it follows a Q4 law, (ii) a slow jump diffusive motion of each chain in the restricted volume defined by other chains, thermally activated with an activation barrier of 8 kcal/mol, and (iii) a fast local diffusive motion with only some fraction of the chains concerned. © 1994 The American Physical Society.