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The last two decades have seen a remarkable growth in the design of new hybrid materials applied to different areas, from photonics to biomaterials, together with new coating materials with self-cleaning features. Among the various systems studied, the PDMS-SiO2 system remains as a good basis for further developments by adding other compounds such as transition metals. In this work, a detailed study of the influence of titanium or zirconium in the chemical structure and final microstructure of such hybrids was made. It was concluded that, due to the lower reactivity of the titanium alkoxide during the sol-gel preparation process, titanium is preferably located on the surface of secondary particles of silica, unlike the zirconium, which being more reactive, positions on the surface of the primary particles. This difference leads to xerogels with dissimilar characteristics and morphologies. (C) 2015 Elsevier Ltd. All rights reserved.

Organic-inorganic materials have been the object of intense research due to their wide range of properties and therefore innumerous applications. We prepared organic-inorganic hybrid materials by direct energy deposition on a mixture of polydimethylsiloxane silanol terminated (33 wt% fixed content), tetraethylorthosilicate and a minor content of zirconium propoxide that varied from 1 to 5 wt% using gamma radiation from a Co-60 source. The samples, dried in air at room temperature, are bulk, flexible and transparent. Their nanostructure was investigated by small angle neutron scattering. It was found that the inorganic oxide network has fractal structure, which becomes denser as the zirconium propoxide content decreases. The results suggest that oxide nanosized regions grow from the OH terminal group of PDMS which are the condensation seeds. Their number and position remains unaltered with the variation of zirconium propoxide content that only affects their microstructure. A model is proposed for the nanostructure of the oxide network that develops in the irradiation processed hybrid materials. (C) 2015 Elsevier B.V. All rights reserved.

In this work we present experimental results about the formation, properties and structure of sol — gel silica based biocomposite containing Calcium alginate as an organic compound. Two different types of silicon precursors have been used in the synthesis: tetramethylortosilicate (TMOS) and ethyltrimethoxysilane (ETMS). The samples have been prepared at room temperature. The hybrids have been synthesized by replacing different quantitis of the inorganic precursor with alginate. The structure of the obtained hybrid materials has been studied by XRD, IR Spectroscopy, EDS, BET and AFM. The results proved that all samples are amorphous possessing a surface area from 70 to 290 m2/g. It has also been established by FT IR spectra that the hybrids containing TMOS display Van der Walls and Hydrogen bonding or electrostatic interactions between the organic and inorganic components. Strong chemical bonds between the inorganic and organic components in the samples with ETMS are present. A self-organized nanostructure has been observed by AFM. In the obtained hybrids the nanobuilding blocks average in size at about 8–14 nm for the particles.

During the last 30 years, a number of genetic code alterations have been uncovered in bacteria and in the mitochondria and cytoplasm of various eukaryotes, invalidating the hypothesis that the genetic code is universal and frozen. In the mitochondria of most yeasts, the UGA stop codon is decoded as tryptophan and the four leucine codons of the CUN family (N = any nucleotide) are decoded as threonine. Recently, a unique genetic code change involving the decoding of the leucine CUG codon as serine was discovered in the cytoplasm of Candida and Debaryomyces species, indicating that the genetic code of yeasts may be under specific evolutionary pressures whose molecular nature is not yet fully understood. This genetic code alteration is mediated by a novel serine-tRNA that acquired a leucine 5′-CAG-3′ anticodon (ser-tRNACAG) through insertion of an adenosine in the intron of its gene. This event, which occurred 272 ± 25 million years ago, reprogrammed the identity of approximately 30 000 CUG codons existent in the ancestor of these yeasts and had a profound impact on the evolution of the genus Candida and of other species. Here, we review the most recent results and concepts arising from the study of this genetic code change and highlight how its study is changing our views of the evolution of the genetic code. Copyright © 2006 John Wiley & Sons, Ltd.

Candida albicans is the most prevalent cause of fungemia worldwide. Its ability to develop resistance in patients receiving azole antifungal therapy is well documented. In a murine model of systemic infection, we show that ibuprofen potentiates fluconazole antifungal activity against a fluconazole-resistant strain, drastically reducing the fungal burden and morbidity. The therapeutic combination of fluconazole with ibuprofen may constitute a new approach for the management of antifungal therapeutics to reverse the resistance conferred by efflux pump overexpression.

This work investigates the influence of the precursor trimethylsilil isocyanate on the sol-gel synthesis of hybrid materials. The obtained Si−O−C−N network is additionally modified by titanium and zirconium alcoxypropoxides in the range of 10 to 30 wt. %. The structure of the obtained hybrid materials before and after pyrolysis up to 1100°C was investigated by methods of XRD, FTIR and 29Si MAS NMR. We established that the hybrid structure was stable up to 600°C based on IR study. The structural transformation of the hybrid materials into oxycarbonitrogen system started at 800°C. The network of the hybrids modified by titanium remained stable and amorphous up to the final temperature of the pyrolysis (1100°C) compared to the gels modified by more than 10 wt.% Zr. It was confirmed by XRD analysis that the last mentioned are nanocomposite materials, built from carbooxynitrogen vitreous matrix and ZrO2-nanocrystals (tetragonal). The NMR method verified the presence of heterometallic bonds (Si−O−Ti and Si−O−Zr) and Q4, ZrQ3 or TiQ3, NSiO3 and D structural units in the gels.

Modified sol-gel processes have been developed for the preparation of lead zirconate titanate (PZT) (52/48) powders. These processes use different starting sources to introduce the titanium and zirconium components, namely tetraethyl orthotitanate, titanium isopropoxide, or titanium diisopropoxide bis(2,4-pentanedionate) for titanium and zirconium propoxide or zirconium acetylacetonate for zirconium. To achieve stable and homogeneous precursor systems, several solvents (acetic acid, 1,2-propanediol, propanol, and distilled water) and chemical modifying additives, such as acetylacetone and nitric acid, were also introduced for the preparation processes. The influence of the different precursors on the crystallization behavior of the sol-gel-derived powders was studied. Well-crystallized single-phase PZT powders were obtained after heat treatment at 600°C for 1 h. The powders obtained sintered well at 1000°C/2 h and a homogeneous microstructure with small grain sizes was obtained.

Lead zirconate titanate (PZT) thin films were prepared on platinized silicon substrates by dip-coating using a modified diol-based sol-gel route without and with up to 5 mol% PZT nanometric seeds dispersed in the precursor sol. A metastable intermetallic Pt x Pb phase formed at the early stages of heat treatment. XRD, TEM, and RBS revealed that the thickness and stoichiometry of the Pt x Pb layer varied with the concentration of seeds and heat treatment of the films. The relation of the Pt x Pb layer to the final crystalline texture of the PZT thin films is reported and discussed.

During the last 30 years, a number of alterations to the standard genetic code have been uncovered both in prokaryotes and eukaryotic nuclear and mitochondrial genomes. But, the study of the evolutionary pathways and molecular mechanisms of codon identity redefinition has been largely ignored due to the assumption that non-standard genetic codes can only evolve through neutral evolutionary mechanisms and that they have no functional significance. The recent discovery of a genetic code change in the genus Candida that evolved through an ambiguous messenger RNA decoding mechanism is bringing that naive assumption to an abrupt end by showing, in a rather dramatic way, that genetic code changes have profound physiological and evolutionary consequences for the species that redefine codon identity. In this paper, the recent data on the evolution of the Candida genetic code are reviewed and an experimental framework based on forced evolution, molecular genetics and comparative and functional genomics methodologies is put forward for the study of non-standard genetic codes and genetic code ambiguity in general. Additionally, the importance of using Saccharomyces cerevisiae as a model organism for elucidating the evolutionary pathway of the Candida and other genetic code changes is emphasised. published

The human pathogen Candida albicans translates the standard leucine-CUG codon as serine. This genetic code change is mediated by a novel ser-tRNA(CAG), which induces aberrant mRNA decoding in vitro, resulting in retardation of the electrophoretic mobility of the polypeptides synthesized in its presence. These non-standard decoding events have been attributed to readthrough of the UAG and UGA stop codons encoded by the Brome Mosaic Virus RNA 4, which codes for the virion coat protein, and the rabbit globin mRNAs, respectively. In order to fully elucidate the behaviour of the C. albicans ser-tRNA(CAG) towards stop codons, we have used other cell-free translation systems and reporter genes. However, the reporter systems used encode several CUG codons, making it impossible to distinguish whether the slow migration of the polypeptides is caused by the replacement of leucines by serines at the CUG codons, readthrough, or a combination of both. Therefore, we have constructed new reporter systems lacking CUG codons and have used them to demonstrate that aberrant mRNA decoding in vitro is not a result from stop codon readthrough or any other non-standard translational event. Our data show that a single leucine to serine replacement at only one of the four CUG codons encoded by the BMV RNA-4 gene is responsible for the aberrant migration of the BMV coat protein on SDS-PAGE, suggesting that this amino acid substitution (ser for leu) significantly alters the structure of the virion coat protein. The data therefore show that the only aberrant event mediated by the ser-tRNA(CAG) is decoding of the leu-CUG codon as serine. published

Acquisition of azole resistance by clinically relevant yeasts in nature may result in a significant, yet undetermined, impact in human health. The main goal of this study was to assess the development of cross-resistance between agricultural and clinical azoles by Candida spp. An in vitro induction assay was performed, for a period of 90 days, with prochloraz (PCZ) - an agricultural antifungal. Afterward, the induced molecular resistance mechanisms were unveiled. MIC value of PCZ increased significantly in all Candida spp. isolates. However, only C. glabrata developed cross-resistance to fluconazole and posaconazole. The increased MIC values were stable. Candida glabrata azole resistance acquisition triggered by PCZ exposure involved the upregulation of the ATP binding cassette multidrug transporter genes and the transcription factor, PDR1. Single mutation previously implicated in azole resistance was found in PDR1 while ERG11 showed several synonymous single nucleotide polymorphisms. These results might explain why C. glabrata is so commonly less susceptible to clinical azoles, suggesting that its exposure to agricultural azole antifungals may be associated to the emergence of cross-resistance. Such studies forward potential explanations for the worldwide increasing clinical prevalence of C. glabrata and the associated worse prognosis of an infection by this species. info:eu-repo/semantics/publishedVersion

Candida krusei is an important agent of opportunistic infections that often displays resistance to several antifungals. We describe here the in vivo acquisition of resistance to voriconazole (VRC) by C. krusei isolates recovered from a leukemia patient during a long period of VRC therapy. In order to mimic the in vivo development of VRC resistance, a susceptible C. krusei isolate was exposed daily to 1 μg/ml of VRC in vitro . Interestingly, after 5 days of exposure to VRC, a MIC of 4 μg/ml was achieved; this value remained constant after 25 additional days of treatment with VRC and also after 30 consecutive days of incubation in VRC-free medium. Our objective was to determine the associated molecular resistance mechanisms, such as expression of efflux pump genes and ERG11 gene mutations, among the resistant strains. Synergistic effects between the efflux blocker tacrolimus (FK506) and VRC were found in all of the resistant strains. Moreover, ABC1 gene expression increased over time in both the in vivo - and in vitro -induced resistant strains, in contrast to the ABC2 and ERG11 genes, whose expression was invariably lower and constant. ERG11 gene sequencing showed two different types of mutations, i.e., heterozygosity at T1389T/C, corresponding to synonymous mutations, in C. krusei strains and a missense mutation at position T418C, resulting in a change from Tyr to His, among resistant C. krusei clinical isolates. This study highlights the relevance of ATP-dependent efflux pump (namely, Abc1p) activity in VRC resistance and describes new mutations in the ERG11 gene among resistant C. krusei clinical isolates.

Background: The purpose of this study was to unveil whether azole antifungals used in agriculture, similar to the clinical azoles used in humans, can evoke resistance among relevant human pathogens like Aspergillus fumigatus, an ubiquitous agent in nature. Additionally, cross-resistance with clinical azoles was investigated. Antifungal susceptibility testing of environmental and clinical isolates of A. fumigatus was performed according to the CLSI M38-A2 protocol. In vitro induction assays were conducted involving daily incubation of susceptible A. fumigatus isolates, at 35°C and 180 rpm, in fresh GYEP broth medium supplemented with Prochloraz (PCZ), a potent agricultural antifungal, for a period of 30 days. Minimal inhibitory concentrations (MIC) of PCZ and clinical azoles were monitored every ten days. In order to assess the stability of the developed MIC, the strains were afterwards sub-cultured for an additional 30 days in the absence of antifungal. Along the in vitro induction process, microscopic and macroscopic cultural observations were registered. Results: MIC of PCZ increased 256 times after the initial exposure; cross-resistance to all tested clinical azoles was observed. The new MIC value of agricultural and of clinical azoles maintained stable in the absence of the selective PCZ pressure. PCZ exposure was also associated to morphological colony changes: macroscopically the colonies became mostly white, losing the typical pigmentation; microscopic examination revealed the absence of conidiation. Conclusions: PCZ exposure induced Aspergillus fumigatus morphological changes and an evident increase of MIC value to PCZ as well as the development of cross-resistance with posaconazole, itraconazole and voriconazole. IFR and IMM are supported by FCT (Fundação Ciência e Tecnologia). IFR is supported by FCT PhD grant (SFRH/BD/91155/2012). I.MM is supported by FCT, Ciência 2008 and co-financed by the European Social Fund. The authors would like to thank Isabel Santos for the excellent technical assistance. Part of the results was presented at the 52nd Interscience Conference on Antimicrobial Agents and Chemotherapy, ICAAC, held San Francisco, USA, September 2012. info:eu-repo/semantics/publishedVersion

Due to its elasticity, transparency and biocompatibility, polydimethylsiloxane (PDMS) has been used as an organic component of hybrid materials in different fields of application such as photonics or biomaterials. Typically an acidic medium is used in the sol-gel processing of PDMS-metal oxide systems due to its catalytic effect. Furthermore, when dealing with highly reactive transition metal alkoxides, a chelating agent is pointed out as being necessary to avoid phase separation. In this work a new approach to the preparation procedure of hybrid materials, based on the system PDMS-SiO2-MO2 with M=Ti or Zr, was used. Samples were prepared at different pH values, without water addition and in the presence or absence of a chelating agent (ethyl acetoacetate). All samples were homogeneous and transparent even at high pH. ATR-IR, Si-29-NMR MAS and Si-29-{H-1} CP-MAS were used for the characterization of the obtained samples. According to the 29Si-{H-1} CP-MAS results some differences in the nature of difunctional D ((CH3)(2)center dot SiO2) and tetrafunctional (SiO4) Q structural units were observed. The presence of Ti-O-Si and Zr-O-Si bonds was confirmed by ATR-IR analysis. (C) 2014 Elsevier B.V. All rights reserved.

Sol–gel derived La modified lead zirconate titanate (PLZT) films were coated on glass substrates by the dip-coating method. The calcination temperature was varied between 490°C and 650°C for 1 h. Films with different thickness from 170 to 700 nm, in which the crystalline phase was randomly formed, were prepared. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to observe the morphology, thickness and phase status of the film, respectively. In conclusion, the thickness limits to the perovskite and pyrochlore phase formations are 150 and 230 nm, respectively. The pyrochlore phase can stabilize in thinner films with a film microstructure of the compositional fluctuation type and the perovskite phase stabilizes in thicker films with a film structure of the crystalline type cluster. The pyrochlore phase will start to transform into the perovskite phase as soon as the thickness is above the limit value for the formation of the perovskite phase. The pure perovskite phase can be obtained by increasing the film thickness to 700 nm at most, instead of increasing the heat treatment temperature of the PLZT thin film.

Lead zirconate titanate (PZT) (52/48) powders were prepared by a sol‐gel process, using different raw materials to introduce the lead component together with several solvents and chemical modifying agents. A study of the effect of these variables on crystallization behavior was conducted to determine the best conditions for preparing monophasic submicrometersized PZT perovskite powders in the morphotropic region. In the present work, well-crystallized, submicrometer-sized single-phase perovskite PZT powders were obtained after heat treatment at 600°C for 1 h. The dependence of this crystallization temperature on the preparation conditions was observed. The sol‐gel-derived submicrometer-sized PZT powders were sintered to ! 96% of relative density after 2 h at 950°‐970°C. The sintered ceramics exhibited a dielectric permittivity of 1000, a piezoelectric coefficient of 135 pC! N ! 1 , a remanent polarization of 20 " C! cm ! 2 , and a coercive field of 10.6 kV! cm ! 1 .

Lead zirconate titanate (PZT) thin films were prepared by the sol-gel process using acetic acid and 1,2-propanediol as solvents. Acetone was used as final solvent and in this way a stable stock sol (for more than 12 months) was obtained. The PZT sols prepared were reproducible and suitable for the preparation of PZT thin films. To study the sol structure evolution gas chromatography mass spectrum (GC-MS) and Fourier-transform-infrared (FT-IR) spectra were recorded and analyzed on each step of the synthesis. The rheological behavior and the stability of the stock sol were checked using a rheometer. It is observed that the addition of acetone leads to a very stable stock sol. The preliminary investigation of the electric properties of the obtained PZT thin films showed that the crystallized films deposited from a fresh prepared sol and a 12 months aged sol exhibit similar ferroelectric properties and comparable to those reported in the literature.

In this paper the electrical properties of PZT (52/48) thin films derived from seeded and unseeded sol–gel precursors are presented. A pure perovskite phase was obtained at lower temperatures, 550°C for 30 min, for film prepared from seeded precursors and deposited on platinum passivated silicon substrates (Pt/Ti/SiO 2 /Si). The electrical properties of these films also reflect the presence or absence of seeds in the precursors. Ferroelectric hysteresis loops began to be observed for seeded films fired at 500°C for 30 min, while in the films derived from unseeded precursors and fired in the same conditions, linear polarization versus electrical field curve is observed.

A new procedure based on an ethanolic solution of the appropriate cations to obtain SrBi 2 Ta 2 O 9 (SBT) thin films is described, reducing the necessity of toxic organicals. According to X-ray diffraction analysis the desired SBT crystalline phase is obtained after heat treatment at 720 °C, in air, for 20 min. The ferroelectric properties of the obtained thin film include a remnant polarization value of 5.0 μC/cm 2 and a coercive field of 50 kV/cm, which are rather good results for a stoichiometric SBT thin film.

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In this work we report on the synthesis of porous amine functionalized organosilica materials prepared by co-condensation of tetraethyl orthosilicate (TEOS) and bis-[3-(trimethoxyosilyl)propyl] amine (BTPA). The gels were prepared through a one-step sol-gel process catalyzed by the - NH- groups of BTPA. A block copolymer poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (P123) was employed as a porogen using the surfactant template method. The resultant materials have been characterized by nitrogen gas sorption, powder X-ray diffraction, FT-IR, SEM, Si-29 MAS NMR, C-13 CP MAS NMR and TG/DTA analysis. In order to examine the potential of these materials as adsorbents for heavy metals, Hg(II) adsorption experiments were also performed. The hybrids showed mesoporous disordered structure as evidenced by N2 adsorption-desorption isotherms and XRD patterns. Adsorption of Hg(II) ions from aqueous solutions showed high capacities suggesting that these materials could be used as adsorbents for Hg(II) ions in acid solutions. (C) 2013 Elsevier B.V. All rights reserved.

The preparation of PDMS–TEOS–CaO hybrid materials by sol–gel techniques has been widely described in previous works. Calcium nitrate is the most common source of calcium used in these preparations. However, to remove possible toxic nitrate by-products a thermal treatment is necessary at temperatures above 500 °C, which leads to the degradation of the polymeric components of the hybrids. Strontium has already shown some promising results in the therapeutic area, being used in cases of osteoporosis and low bone density. In this study a new potential bioactive hybrid material was prepared, by sol–gel techniques, using calcium acetate as a novel calcium source. Also, for the first time, incorporation of strontium in a PDMS–TEOS hybrid system was evaluated. Samples were characterized before and after immersion in Kokubo's Simulated Body Fluid (SBF) by SEM, EDS, ICP and FT-IR spectroscopy.

A new type of material from polyamide coated with calcium phosphate was developed aiming to have potential application as biomaterial. Coating was obtained by the sol-gel method and calcium phosphate was obtained after contact with body fluid solution. The coated polyamide (before and after contact with body fluid solution) was characterized by thermogravimetric and differential thermal (TGA/DTA) analyses, differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR). These characterizations revealed that the calcium phosphate coating has a thickness of less than 3 µm, which resulted in an increase in the melting point and improved the thermal stability of polyamide. After contact with body fluid, the interactions between the coating and the substrate remained, and there was formation of crystalline and amorphous phosphates on polyamide surface. Um novo material a base de poliamida revestida com fosfato de cálcio foi desenvolvido visando potencial aplicação como biomaterial. O revestimento foi obtido pelo método sol-gel e o fosfato de cálcio foi obtido após contato com solução de fluído corpóreo. A poliamida revestida (antes e depois de contado com fluído corpóreo) foi caracterizada através de análises termogravimétrica e térmica diferencial (TGA/DTA), calorimetria diferencial de varredura (DSC), microscopia eletrônica de varredura (SEM) e espectrometria de reflexão total atenuada no infravermelho com transformada de Fourier (ATR-FTIR). As caracterizações revelaram a formação de fosfato de cálcio com uma espessura menor que 3 µm, o que proporcionou um aumento no ponto de fusão além de melhorar a estabilidade térmica da poliamida. Após contato com o fluído corpóreo, as interações entre o revestimento e o substrato se mantiveram, e houve formação de fosfatos cristalinos e amorfos na superfície de poliamida.

Methylcellulose (MC) / SiO2 organic / inorganic hybrid materials have been prepared from MC and methyltriethoxysilane or ethyltrimethoxysilane, and characterized by XRD, FTIR and AFM. XRD showed peak shifts. FTIR shows intermolecular hydrogen bonding between MC and SiO2. AFM depicts surface roughness which depends on the silica precursor and MC content.

This is the first case report of Candida glabrata -disseminated candidiasis describing the acquisition of echinocandin resistance following anidulafungin treatment. The initial isolates recovered were susceptible to echinocandins. However, during 27 days of anidulafungin treatment, two resistant strains were isolated (from the blood and peritoneal fluid). The resistant peritoneal fluid isolate exhibited a Ser663Pro mutation in position 1987 of FKS2 HS1 (hot spot 1), whereas the resistant blood isolate displayed a phenylalanine deletion (Phe659).

The crystallization behaviour of hybrid SiO2-TiO2 nanocomposites derived from titanosiloxanes by sol-gel method has been investigated depending on the type of siloxane precursor and the pirolysis temperature. The resulting hybrid titanosiloxanes, crosslinked with trimethylsilil isocyanate (nitrogen-modified) or methyltrietoxisilane (carbon-modified), were pirolyzed in an inert atmosphere in the temperature range between 600 to 1100 degrees C in order to form C-(N)-Si-O-TiO2 nanocomposites. By means of XRD, FTIR, 29Si NMR, SEM, TEM and AFM investigations have been established that the transformation of the nanostructured SiO2-TiO2 hybrid materials into nanocomposites as well as the crystalline size depend on the titanium content and the type of cross-linking agents used in the synthesizes.

Candida parapsilosis , an emergent agent of nosocomial infections, was previously made up of a complex of three genetically distinct groups (groups I, II, and III). Recently, the C. parapsilosis groups have been renamed as distinct species: C. parapsilosis sensu stricto, C. orthopsilosis , and C. metapsilosis . In Portugal, no data pertaining to the distribution and antifungal susceptibility of these Candida species are yet available. In the present report, we describe the incidence and distribution of C. parapsilosis sensu stricto, C. orthopsilosis , and C. metapsilosis among 175 clinical and environmental isolates previously identified by conventional methods as C. parapsilosis . We also evaluated the in vitro susceptibilities of the isolates to fluconazole, voriconazole, posaconazole, amphotericin B, and two echinocandins, caspofungin and anidulafungin. Of the 175 isolates tested, 160 (91.4%) were identified as C. parapsilosis sensu stricto, 4 (2.3%) were identified as C. orthopsilosis , and 5 (2.9%) were identified as C. metapsilosis . Six isolates corresponded to species other than the C. parapsilosis group. Interestingly, all isolates from blood cultures corresponded to C. parapsilosis sensu stricto. Evaluation of the antifungal susceptibility profile showed that only nine (5.6%) C. parapsilosis sensu stricto strains were susceptible-dose dependent or resistant to fluconazole, and a single strain displayed a multiazole-resistant phenotype; two (1.3%) C. parapsilosis sensu stricto strains were amphotericin B resistant. All C. orthopsilosis and C. metapsilosis isolates were susceptible to azoles and amphotericin B. A high number of strains were nonsusceptible to the echinocandins (caspofungin and anidulafungin).

The present work describes the synthesis of ferroelectric-ferrimagnetic multilayers for possible device applications. Sol-gel spin coating technique is employed for the synthesis of heterolayers consisting of PZT and nickel ferrite using nitrate precursors. The multilayers are sintered in a rapid sintering process. The morphological characterization using AFM shows that the formed multilayers are smooth, with nanosized grains. The local piezoelectric measurements using PFM deliver a piezoelectric loop even if the multilayers consist of small grained PZT particles. The magnetic characterization using SQUID shows ferromagnetic ordering.

Background The discovery of genetic code alterations and expansions in both prokaryotes and eukaryotes abolished the hypothesis of a frozen and universal genetic code and exposed unanticipated flexibility in codon and amino acid assignments. It is now clear that codon identity alterations involve sense and non-sense codons and can occur in organisms with complex genomes and proteomes. However, the biological functions, the molecular mechanisms of evolution and the diversity of genetic code alterations remain largely unknown. In various species of the genus Candida, the leucine CUG codon is decoded as serine by a unique serine tRNA that contains a leucine 5′-CAG-3′anticodon (tRNACAGSer). We are using this codon identity redefinition as a model system to elucidate the evolution of genetic code alterations. Methodology/Principal Findings We have reconstructed the early stages of the Candida genetic code alteration by engineering tRNAs that partially reverted the identity of serine CUG codons back to their standard leucine meaning. Such genetic code manipulation had profound cellular consequences as it exposed important morphological variation, altered gene expression, re-arranged the karyotype, increased cell-cell adhesion and secretion of hydrolytic enzymes. Conclusion/Significance Our study provides the first experimental evidence for an important role of genetic code alterations as generators of phenotypic diversity of high selective potential and supports the hypothesis that they speed up evolution of new phenotypes.

During the last 30 years, several alterations to the standard genetic code have been discovered in various bacterial and eukaryotic species. Sense and nonsense codons have been reassigned or reprogrammed to expand the genetic code to selenocysteine and pyrrolysine. These discoveries highlight unexpected flexibility in the genetic code, but do not elucidate how the organisms survived the proteome chaos generated by codon identity redefinition. In order to shed new light on this question, we have reconstructed a Candida genetic code alteration in Saccharomyces cerevisiae and used a combination of DNA microarrays, proteomics and genetics approaches to evaluate its impact on gene expression, adaptation and sexual reproduction. This genetic manipulation blocked mating, locked yeast in a diploid state, remodelled gene expression and created stress cross-protection that generated adaptive advantages under environmental challenging conditions. This study highlights unanticipated roles for codon identity redefinition during the evolution of the genus Candida, and strongly suggests that genetic code alterations create genetic barriers that speed up speciation. published

An unusual decoding of leucine CUG codons as serine in Candida albicans revealed unanticipated codon ambiguity, which expands the proteome of this human pathogen exponentially., Background Genetic code alterations have been reported in mitochondrial, prokaryotic, and eukaryotic cytoplasmic translation systems, but their evolution and how organisms cope and survive such dramatic genetic events are not understood. Results Here we used an unusual decoding of leucine CUG codons as serine in the main human fungal pathogen Candida albicans to elucidate the global impact of genetic code alterations on the proteome. We show that C. albicans decodes CUG codons ambiguously and tolerates partial reversion of their identity from serine back to leucine on a genome-wide scale. Conclusion Such codon ambiguity expands the proteome of this human pathogen exponentially and is used to generate important phenotypic diversity. This study highlights novel features of C. albicans biology and unanticipated roles for codon ambiguity in the evolution of the genetic code.

Metallic implants and devices are widely used in the orthopedic and orthodontic clinical areas. However, several problems regarding their adhesion with the living tissues and inflammatory responses due to the release of metallic ions to the medium have been reported. The modification of the metallic surfaces and the use of biocompatible protective coatings are two approaches to solve such issues. In this study, in order to improve the adhesion properties and to increase the corrosion resistance of metallic Ti substrates we have obtained a hybrid structure based on TiO2 nanotubular arrays and PDMS-TEOS films. TiO2 nanotubes have been prepared with two different diameters by means of electrochemical anodization. PDMS-TEOS films have been prepared by the sol-gel method. The morphological and the elemental analysis of the structures have been investigated by scanning electron microscopy and energy dispersive spectroscopy (EDS). Electrochemical impedance spectroscopy (EIS) and polarization curves have been performed during immersion of the samples in Kokubo's simulated body fluid (SBF) at 37 degrees C to study the effect of structure layers and tube diameter on the protective properties. The obtained results show that the modification of the surface structure of TiO2 and the application of PDMS-TEOS film is a promising strategy for the development of implant materials.

Objective To evaluate the frequency of microalbuminuria and its relationship with several risk factors and left ventricular mass in a population of mildly hypertensive subjects attended in a primary-care setting. Design Cross-sectional study. Setting Eight primary-care centres. Patients Two hundred and twenty-three non-diabetic patients recently diagnosed with mild hypertension were included in the study. None of them had clinical evidence of target-organ damage or had received prior antihypertensive treatment. Interventions Subjects included in the study underwent clinical interview, measurement of blood pressure (BP) on three visits, blood analysis, measurement of albumin by immunonephelometry in three overnight urine collections, 24 h BP monitoring and M-mode and Doppler echocardiography. Main outcome measures Tobacco habit, clinic BP, body mass index, serum lipids and uric acid, glycaemia, urinary albumin excretion (UAE), ambulatory BP and left ventricular mass index. Results The frequency of microalbuminuria was 7.2%. Microalbuminuric patients were more likely to be men and to be characterized by higher ambulatory BP, body mass index and uric acid levels. Regression analysis demonstrated that male sex and 24 h systolic BP were determinants of UAE. Patients with white-coat hypertension showed lower UAE than did subjects with sustained hypertension. Although a certain relationship between UAE and left ventricular mass index was found, these variables were not significantly correlated. Conclusions A low proportion of mildly hypertensive patients attended in a primary care setting are microalbuminuric. In this population, UAE is an expression of BP values over 24 h and correlates with several risk factors.

Lead zirconate titanate (PZT) (52/48) powders were prepared by a sol‐gel process, using different raw materials to introduce the lead component together with several solvents and chemical modifying agents. A study of the effect of these variables on crystallization behavior was conducted to determine the best conditions for preparing monophasic submicrometersized PZT perovskite powders in the morphotropic region. In the present work, well-crystallized, submicrometer-sized single-phase perovskite PZT powders were obtained after heat treatment at 600°C for 1 h. The dependence of this crystallization temperature on the preparation conditions was observed. The sol‐gel-derived submicrometer-sized PZT powders were sintered to ! 96% of relative density after 2 h at 950°‐970°C. The sintered ceramics exhibited a dielectric permittivity of 1000, a piezoelectric coefficient of 135 pC! N ! 1 , a remanent polarization of 20 " C! cm ! 2 , and a coercive field of 10.6 kV! cm ! 1 .

Polyzirconosiloxanes were synthesised trough the hydrolytic co-condensation of tetraethoxysilane (TEOS), methyltriethoxysilane (MTES) and zirconium isopropoxide (ZIP) (Process A) or tetramethoxysilane (TMOS), trimethylsilyl isocyanate (TMSI) and ZIP (Process B). In both processes, ethylacetoacetat was added to provide ethylacetato derivatives of polyzirconosyloxanes. When the obtained hybrids were subjected to heat treatment, the zirconia component crystallises in nano size. The XRD, FTIR and 29Si NMR showed that the crystallisation depends on the random and block sequence in the main chain of the polyzirconosiloxanes derived from Processes A and B, respectively.