One-pot synthesis of silica monoliths with hierarchically porous structure

Poly(furfuryl alcohol) (PFA) and block copolymer Pluronic F127 were used as pore templates to create mechanically robust silica monoliths with a hierarchical and interconnected macro?mesoporous network in an easy, reproducible bimodal scale templating process. Control over the morphology was obtained by varying the reactant ratios. Phase separation on the submicrometer scale occurred when furfuryl alcohol was cationically polymerized and therefore became immiscible with the solvent and the silica precursor. Upon a subsequent sol?gel reaction, a silica-F127 matrix formed around the PFA spheres, leading to macropore structures with mesoporous walls. Surface areas of the final structures ranged from 500 to 989 m2/g and a maximum pore volume of 4.5 mL/g was achieved. Under mildly acidic conditions, micelle-templated mesopores resulted. Interconnected macropores could be obtained by increasing the pH or the block copolymer concentration. The formation mechanism and the relationship between PFA, Pluronic F127 and acidity are discussed in detail.Fil: Drisko, Glenna L.. University of Melbourne; AustraliaFil: Zelcer, Andrés. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Caruso, Rachel A.. University of Melbourne; AustraliaFil: Soler Illia, Galo Juan de Avila Arturo. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentin

Synthesis and photocatalytic activity of titania monoliths prepared with controlled macro- and mesopore structure

Herein, we report a one-pot synthesis of crack-free titania monoliths with hierarchical macro-mesoporosity and crystalline anatase walls. Bimodal macroporosity is created through the polymer-induced phase separation of poly(furfuryl alcohol). The cationic polymerization of furfuryl alcohol is performed in situ and subsequently the polymer becomes immiscible with the aqueous phase, which includes titanic acid. Addition of template, Pluronic F127, increases the mesopore volume and diameter of the resulting titania, as the poly(ethylene glycol) block interacts with the titania precursor, leading to assisted assembly of the metal oxide framework. The hydrophobic poly(propylene glycol) micelle core could itself be swollen with monomeric and oligomeric furfuryl alcohol, allowing for mesopores as large as 18 nm. Variations in synthesis parameters affect porosity; for instance furfuryl alcohol content changes the size and texture of the macropores, water content changes the grain size of the titania and Pluronic F127 content changes the size and volume of the mesopore. Morphological manipulation improves the photocatalytic degradation of methylene blue. Light can penetrate several millimeters into the porous monolith, giving these materials possible application in commercial devices.Fil: Drisko, Glenna L.. University of Melbourne; AustraliaFil: Zelcer, Andrés. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; ArgentinaFil: Wang, Xingdong. Commonwealth Scientific And Industrial Research Organization; AustraliaFil: Caruso, Rachel A.. School Of Chemistry; Australia. Commonwealth Scientific And Industrial Research Organization; AustraliaFil: Soler Illia, Galo Juan de Avila Arturo. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Dynamic changes in lung microRNA profiles during the development of pulmonary hypertension due to chronic hypoxia and monocrotaline

<b>Objective</b>: MicroRNAs (miRNAs) are small noncoding RNAs that have the capacity to control protein production through binding "seed" sequences within a target mRNA. Each miRNA is capable of potentially controlling hundreds of genes. The regulation of miRNAs in the lung during the development of pulmonary arterial hypertension (PAH) is unknown.<p></p> <b>Methods and Results</b>: We screened lung miRNA profiles in a longitudinal and crossover design during the development of PAH caused by chronic hypoxia or monocrotaline in rats. We identified reduced expression of Dicer, involved in miRNA processing, during the onset of PAH after hypoxia. MiR-22, miR-30, and let-7f were downregulated, whereas miR-322 and miR-451 were upregulated significantly during the development of PAH in both models. Differences were observed between monocrotaline and chronic hypoxia. For example, miR-21 and let-7a were significantly reduced only in monocrotaline-treated rats. MiRNAs that were significantly regulated were validated by quantitative polymerase chain reaction. By using in vitro studies, we demonstrated that hypoxia and growth factors implicated in PAH induced similar changes in miRNA expression. Furthermore, we confirmed miR-21 downregulation in human lung tissue and serum from patients with idiopathic PAH.<p></p> <b>Conclusion</b>: Defined miRNAs are regulated during the development of PAH in rats. Therefore, miRNAs may contribute to the pathogenesis of PAH and represent a novel opportunity for therapeutic intervention.<p></p&gt

One-pot synthesis of hierarchically structured ceramic monoliths with adjustable porosity

Hierarchically porous oxides are used in a variety of applications within the energy sector (e.g., fuel cells, batteries), biology (e.g., scaffolds, biocatalysis), separations, and catalysis. This article describes a reproducible one-step method for the preparation of metal oxides with controllable hierarchical pore architectures. The preparation is demonstrated for a wide range of materials, specifically silica, titania, zirconia, aluminum titanium oxide, titanium zirconium oxide, and yttrium zirconium oxide monoliths. The samples were prepared by exploiting the polymerization and phase separation of furfuryl alcohol to produce a colloidal dispersion of poly(furfuryl alcohol) particles. The gelation in the sol-gel process occurred after the in situ formation of the template. The removal of the polymer template led to the formation of macropores, whereas inclusion of an amphiphilic block copolymer (Pluronic F127) assisted mesopore formation, either by templating or by stabilizing the inorganic building blocks. The macropore and mesopore morphology could be altered by varying the synthesis conditions. This control over the pore structure was demonstrated in the silica, titania, and titanium zirconium oxide materials.Fil: Drisko, Glenna L.. University of Melbourne; AustraliaFil: Zelcer, Andrés. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Luca, Vittorio. Comisión Nacional de Energía Atómica; ArgentinaFil: Caruso, Rachel A.. University of Melbourne; AustraliaFil: Soler Illia, Galo Juan de Avila Arturo. Comisión Nacional de Energía Atómica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Dye-Sensitized Solar Cells Employing a Single Film of Mesoporous TiO2 Beads Achieve Power Conversion Efficiencies Over 10%

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Direct spun aligned carbon nanotube web-reinforced proton exchange membranes for fuel cells

A composite membrane prepared by electrospinning SPEEK and direct spinning of CNTs is more robust than SPEEK alone and outperforms SPEEK and Nafion 212 membranes.</p

Genome-wide association study identifies peanut allergy-specific loci and evidence of epigenetic mediation in US children

Food allergy (FA) affects 2%-10% of US children and is a growing clinical and public health problem. Here we conduct the first genome-wide association study of well-defined FA, including specific subtypes (peanut, milk and egg) in 2,759 US participants (1,315 children and 1,444 parents) from the Chicago Food Allergy Study, and identify peanut allergy (PA)-specific loci in the HLA-DR and -DQ gene region at 6p21.32, tagged by rs7192 (P=5.5 × 10 -8) and rs9275596 (P=6.8 × 10 -10), in 2,197 participants of European ancestry. We replicate these associations in an independent sample of European ancestry. These associations are further supported by meta-analyses across the discovery and replication samples. Both single-nucleotide polymorphisms (SNPs) are associated with differential DNA methylation levels at multiple CpG sites (

Expanding the diversity of mycobacteriophages: insights into genome architecture and evolution.

Mycobacteriophages are viruses that infect mycobacterial hosts such as Mycobacterium smegmatis and Mycobacterium tuberculosis. All mycobacteriophages characterized to date are dsDNA tailed phages, and have either siphoviral or myoviral morphotypes. However, their genetic diversity is considerable, and although sixty-two genomes have been sequenced and comparatively analyzed, these likely represent only a small portion of the diversity of the mycobacteriophage population at large. Here we report the isolation, sequencing and comparative genomic analysis of 18 new mycobacteriophages isolated from geographically distinct locations within the United States. Although no clear correlation between location and genome type can be discerned, these genomes expand our knowledge of mycobacteriophage diversity and enhance our understanding of the roles of mobile elements in viral evolution. Expansion of the number of mycobacteriophages grouped within Cluster A provides insights into the basis of immune specificity in these temperate phages, and we also describe a novel example of apparent immunity theft. The isolation and genomic analysis of bacteriophages by freshman college students provides an example of an authentic research experience for novice scientists

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead