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Zinc oxide nanocrystallites down to 1.5 nm in diameter were made by spray combustion of Zn/Si precursors. These crystallites exhibit a quantum size effect: blueshift of light absorption with decreasing crystallite size. X-ray diffraction, high-resolution transmission electron microscopy, and nitrogen adsorption showed that the addition of controlled amounts of silica prevented the growth and stabilized the ZnO crystals. The blue shift of the ultraviolet-vis absorption edge with decreasing ZnO crystal size closely followed a correlation between optical band gap and crystallite size from the literature. The band-gap energy of these ZnO quantum dots increased with silica content in the spray and particles consistently. The as-prepared quantum dots were stable and did not require any post processing. [ABSTRACT FROM AUTHOR]

Outdoor clothing traditionally contains large numbers of fluorinated organic compounds to provide water vapour permeability (breathability) and protection against rain water. Persistence and bioaccumulation of such chemicals, however, have resulted in their partial ban (Stockholm protocol by the United Nations, 2009). In this study, we show how a simple pore inside coating provides polymer membranes from stearic acid, limestone and elastomers. The selective coating of a pore's inside is based on first providing a core/shell limestone particle, its incorporation into the elastomer, and subsequent dissolution of the limestone core through dilute acid, leaving the former shell within the polymer pore. The process is transferred to a continuous roll-to-roll coating pilot machine, manufacturing at the m2 scale. The produced membrane is laminated to a textile, and finally tailored into a functional outdoor jacket. The process demonstrated here to selectively alter pore surfaces serves as a platform membrane technology that is broadly applicable to other polymers and provides a new way to membrane manufacturing. [ABSTRACT FROM AUTHOR]

Volatile anaesthetics such as sevoflurane attenuate inflammatory processes, thereby impacting patient outcome significantly. Their inhalative administration is, however, strictly limited to controlled environments such as operating theatres, and thus an intravenously injectable immunomodulatory drug would offer distinct advantages. As protective effects of volatile anaesthetics have been associated with the presence of trifluorinated carbon groups in their basic structure, in this study we investigated the water-soluble sevoflurane metabolite hexafluoro-2-propanol (HFIP) as a potential immunomodulatory drug in a rat model of endotoxic shock. Male Wistar rats were subjected to intravenous lipopolysaccharide (LPS) and thereafter were treated with HFIP. Plasma and tissue inflammatory mediators, neutrophil invasion, tissue damage and haemodynamic stability were the dedicated end-points. In an endotoxin-induced endothelial cell injury model, underlying mechanisms were elucidated using gene expression and gene reporter analyses. HFIP reduced the systemic inflammatory response significantly and decreased endotoxin-induced tissue damage. Additionally, the LPS-provoked drop in blood pressure of animals was resolved by HFIP treatment. Pathway analysis revealed that the observed attenuation of the inflammatory process was associated with reduced nuclear factor kappa B (NF-κΒ) activation and suppression of its dependent transcripts. Taken together, intravenous administration of HFIP exerts promising immunomodulatory effects in endotoxaemic rats. The possibility of intravenous administration would overcome limitations of volatile anaesthetics, and thus HFIP might therefore represent an interesting future drug candidate for states of severe inflammation. [ABSTRACT FROM AUTHOR]

Research efforts in the past two decades have resulted in thousands of potential application areas for nanoparticles – which materials have become industrially relevant? Where are sustainable applications of nanoparticles replacing traditional processing and materials? This tutorial review starts with a brief analysis on what makes nanoparticles attractive to chemical product design. The article highlights established industrial applications of nanoparticles and then moves to rapidly emerging applications in the chemical industry and discusses future research directions. Contributions from large companies, academia and high-tech start-ups are used to elucidate where academic nanoparticle research has revolutionized industry practice. A nanomaterial-focused analysis discusses new trends, such as particles with an identity, and the influence of modern instrument advances in the development of novel industrial products. [ABSTRACT FROM AUTHOR]

Recent studies report promising results regarding extracorporeal magnetic separation-based blood purification for the rapid and selective removal of disease-causing compounds from whole blood. High molecular weight compounds, bacteria and cells can be eliminated from blood within minutes, hence offering novel treatment strategies for the management of intoxications and blood stream infections. However, risks associated with incomplete particle separation and the biological consequences of particles entering circulation remain largely unclear. This article discusses the promising future of magnetic separation-based purification while keeping important safety considerations in mind. [ABSTRACT FROM AUTHOR]

For the first time Knoevenagel condensation has been catalyzed by elemental copper with unexpected activity and excellent isolated yields. Inexpensive, widely available copper powder was used to catalyze the condensation of cyanoacetate and benzaldehyde under mild conditions. To ensure general applicability, a wide variety of different substrates was successfully reacted. [ABSTRACT FROM AUTHOR]

Recent studies report promising results regarding extracorporeal magnetic separation-based blood purification for the rapid and selective removal of disease-causing compounds from whole blood. High molecular weight compounds, bacteria and cells can be eliminated from blood within minutes, hence offering novel treatment strategies for the management of intoxications and blood stream infections. However, risks associated with incomplete particle separation and the biological consequences of particles entering circulation remain largely unclear. This article discusses the promising future of magnetic separation-based purification while keeping important safety considerations in mind. [ABSTRACT FROM AUTHOR]

Ecological networks such as food webs are extremely complex and can provide important information about the robustness and productivity of an ecosystem. In most cases, it is not feasible to observe trophic interactions between predators and prey directly and with the available methods, it is difficult to quantify the connections between them. Here, we show that submicron-sized silica particles (100-150 nm) with encapsulated DNA ( SPED) enable accurate food and organism labelling and quantification of specific animal-to-animal transfer over more than one trophic level. We found that SPED were readily transferable and quantifiable from the bottom to the top of a two-level food chain of arthropods. SPED were taken up in the gut system and remained persistent in an animal over several days. When uniquely labelled SPED were applied at predefined ratios, we found that information about their relative abundance was reliably conserved after trophic level transfer and over time. SPED were also applied to investigate the flower preference of fly pollinators and proved to be a fast and accurate analysis method. SPED combine attributes of DNA barcoding and stable isotope analysis such as unique labelling, quantification via real-time PCR and exact backtracking to the tracer source. This improves and simplifies the analysis and monitoring of ecological networks. [ABSTRACT FROM AUTHOR]

Ferromagnetic nanoparticles are covalently modified in order to enhance the dispersion stability as well as the antifouling properties. Insertion of an azide moiety allows “click”-reaction of a relevant tag molecule. This and the high saturation magnetization of the presented nanocomposite offer a promising platform for magnetic biosensors. [ABSTRACT FROM AUTHOR]

Removal of volatile organic compounds (VOC) and indoor air quality regulation through adsorbers required exchange or maintenance of active materials. In this work, we combine well known VOC adsorbers with oxidation catalysts as intimate particulate mixtures. We demonstrate how typical VOC can subsequently adsorb on such mixed material fixed beds (usually days to weeks; the common state of the system, adsorption phase) using small organic compounds (diethyl ether, triethylamine), monoterpenes such as linalool and limonene, and hexanoic acid. Occasional regeneration runs through heat up of the fixed bed results in simultaneous desorption and oxidation of the accumulated VOC, thus regenerating full adsorption capacity for a next adsorption phase. We investigated both small pore zeolites (H-ZSM-5) and larger pore zeolites (13X) and found a distinct interplay between the pore size and the type of VOC. Thermogravimetry coupled with mass spectroscopy was used to quantitatively study the effects of mixing composition and temperature on adsorber performance and regeneration. The here investigated bi-functional systems combine very low maintenance costs and materials requirement with low air flow and exchange costs, thus suggesting mixed (two-functional) bed adsorbers with catalytic function as sustainable alternatives to currently used single use systems based on granulated zeolites or activated carbon. In this work we show the ability of zeolite/cerium oxide physical mixtures to adsorb and capture different classes of VOC at room temperature and release them for oxidation at higher temperatures in a regenerative and sustainable process. [ABSTRACT FROM AUTHOR]

Mohn D, Bruhin C, Luechinger NA, Stark WJ, Imfeld T, Zehnder M. Composites made of flame-sprayed bioactive glass 45S5 and polymers: bioactivity and immediate sealing properties. International Endodontic Journal, 43, 1037-1046, 2010. Aim To engineer systems using polyisoprene (PI) or polycaprolactone (PCL) and nanometric bioactive glass 45S5 (BG) that could create a hydroxyapatite interface and thus ultimately make the use of an endodontic sealer unnecessary. Methodology Different composites using PI or PCL as matrix material were prepared with BG contents of up to 30 wt%. Unfilled PI and PCL, commercially available filled PI (Obtura gutta-percha) and PCL pellets (Resilon) served as control materials. Bioactivity ( in vitro precipitate formation in simulated body fluid) was investigated using scanning electron microscopy and X-ray diffraction analysis. To test immediate sealing ability, simulated root canals were filled with heated materials, and dye leakage was assessed. Leakage was statistically compared between groups using Kruskal-Wallis analysis of variance followed by Mann-Whitney U tests and Bonferroni correction. The alpha-type error was set at 0.05. Results Both composite systems revealed hydroxyapatite formation on their surface. This was not observed on control materials. Incorporating 30 wt% BG into PI and PCL significantly ( P < 0.05) improved their immediate sealing ability compared to that of unfilled polymers, so that dye leakage in simulated root canals was prevented completely. Conclusion Polyisoprene and PCL composites with BG showed promising results as single root canal filling materials. Incorporation of BG fillers into the polymers under investigation made the resulting composite materials bioactive and improved their immediate sealing ability. [ABSTRACT FROM AUTHOR]

Mohn D, Zehnder M, Imfeld T, Stark WJ. Radio-opaque nanosized bioactive glass for potential root canal application: evaluation of radiopacity, bioactivity and alkaline capacity. International Endodontic Journal, 43, 210–217, 2010. Aim To produce novel nanosized bioactive glass particles with radio-opaque properties and high alkaline capacity and to evaluate their performance as a potential bioactive root canal dressing or filling material. Methodology Flame spray-derived bioactive glass particles in the nanometre range were produced including bismuth oxide as a radiopacifier. Calcium hydroxide, barium sulphate and bismuth oxide served as controls. Corresponding materials were compressed to obtain dense specimens with increased alkaline capacity. Radiopacity was evaluated, and in vitro bioactivity was monitored using Raman spectroscopy and scanning electron microscopy. Leaching of bismuth was controlled using atomic absorption spectroscopy. Results Bioactive glass particles with up to 50 wt% bismuth oxide revealed radiopacity with an equivalent of 4.94-mm aluminium. The introduction of bismuth into the bioactive glass altered the alkaline capacity and the in vitro bioactivity only for high bismuth oxide quantities. Bismuth oxide leaching out of the glass matrix was hardly detectable. Conclusion Bioactive glass can be modified with bismuth oxide to become radio-opaque. [ABSTRACT FROM AUTHOR]

An ideal preparation of 45S5 bioactive glass suspensions/slurries for root canal disinfection should combine high pH induction with capacity for continuing release of alkaline species. The hypothesis of this study was that more material per volume of bioactive glass slurry is obtained with a micrometric material (< 5 µm particle size) or a micrometric/nanometric hybrid, rather than a solely nanometric counterpart. This should correlate with alkaline capacity and antimicrobial effectiveness. Slurries at the plastic limit were prepared with test and reference materials in physiological saline. Total mass and specific surface area of glass material per volume were determined. Continuous titration with hydrochloric acid was performed, and antimicrobial effectiveness was tested in extracted human premolars mono-infected with E. faecalis ATTC 29212 (N = 12 per material). While the nanometric slurry had a 12-fold higher specific surface area than the micrometric counterpart, the latter had a considerably higher alkaline capacity and disinfected significantly better (Fisher's exact test, P < 0.05). The hybrid slurry behaved similarly to the micrometric preparation. [ABSTRACT FROM AUTHOR]

Aim To test whether bioactive glasses kill microbiota via mineralization or the release of ions other than sodium. Methodology Flame-spray synthesis was applied to produce nanometric glasses of different sodium content and constant Ca/P ratio: 28S5, 45S5 and 77S. Calcium hydroxide and nanometric tricalcium phosphate (TCP) were used as controls. Apatite induction was monitored by Raman spectroscopy. Bovine dentine disks with adherent Enterococcus faecalis cells were exposed to test and control suspensions or buffered solutions for 1 h, 1 day and 1 week. Colony-forming units were counted and disks were inspected using scanning electron microscopy. Suspension supernatants and solutions were analysed for their pH, osmolarity, calcium and silicon content. Results Sodium containing glasses induced pH levels above 12, compared with less than pH 9 with sodium-free 77S. Calcium hydroxide, 45S5 and 28S5 killed all bacteria after 1 day and lysed them after 1 week. TCP caused the highest apatite induction and substantial calcification on bacteria adhering to dentine, but did not reduce viable counts. 77S achieved disinfection after 1 week without visible apatite formation, whilst the buffer solution at pH 9 caused only minimal reduction in counts. Conclusion Bioactive glasses have a directly and an indirectly pH-related antibacterial effect. The effect not directly linked to pH is because of ion release rather than mineralization. [ABSTRACT FROM AUTHOR]

Aim To investigate the mechanical, chemical and structural alterations of human root dentine following exposure to ascending sodium hypochlorite concentrations. Methodology Three-point bending tests were carried out on standardized root dentine bars ( n = 8 per group, sectioned from sound extracted human third molar teeth) to evaluate their flexural strength and modulus of elasticity after immersion in 5 mL of water (control), 1% NaOCl, 5% NaOCl or 9% NaOCl at 37 °C for 1 h. Additional dentine specimens were studied using microelemental analysis, light microscopy following bulk staining with basic fuchsin, and scanning electron microscopy (SEM). Numerical data were compared using one-wayanova. Bonferroni's correction was applied for multiple testing. Results Immersion in 1% NaOCl did not cause a significant drop in elastic modulus or flexural strength values in comparison to water, whilst immersion in 5% and 9% hypochlorite reduced these values by half ( P < 0.05). Both, carbon and nitrogen contents of the specimens were significantly ( P < 0.05) reduced by 5% and 9% NaOCl, whilst 1% NaOCl had no such effect. Exposure to 5% NaOCl rendered the superficial 80–100 μm of the intertubular dentine permeable to basic fuchsin. Three-dimensional SEM reconstructions of partly demineralized specimens showed NaOCl concentration-dependent matrix deterioration. Backscattered electron micrographs revealed that hypochlorite at any of the tested concentrations left the inorganic dentine components intact. Conclusions The current data link the concentration-dependent hypochlorite effect on the mechanical dentine properties with the dissolution of organic dentine components. [ABSTRACT FROM AUTHOR]

Most recent advances in nanomaterials fabrication have given access to complex materials such as SiO2-Na2O-CaO-P2O5 bioactive glasses in the form of amorphous nanoparticles of 20- to 60-nm size. The clinically interesting antimicrobial properties of commercially available, micronsized bioactive glass 45S5 have been attributed to the continuous liberation of alkaline species during application. Here, we tested the hypothesis that, based on its more than ten-fold higher specific surface area, nanometric bioactive glass releases more alkaline species, and consequently displays a stronger antimicrobial effect, than the currently applied micron-sized material. Ionic dissolution profiles were monitored in simulated body fluid. Antimicrobial efficacy was assessed against clinical isolates of enterococci from persisting root canal infections. The shift from micron- to nano-sized treatment materials afforded a ten-fold increase in silica release and solution pH elevation by more than three units. Furthermore, the killing efficacy was substantially higher with the new material against all tested strains. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the combined phacoemulsification with acrylic intraocular lens implantation and trabeculectomy with releasable sutures, without the use of antimetabolites, performed by one surgeon. Methods: A retrospective analysis was performed on 251 eyes of 198 patients after a combined phaco/trabeculectomy procedure, followed up for an average of 16 months for vision, intraocular pressure (IOP), and number of glaucoma medications. Cox proportional hazard regression analysis provided measures of relative risk (RR) or hazards ratios and 95% confidence intervals (Cls) associated with the occurrence of several conditions or complications of surgery. Results: Mean preoperative variables were best corrected vision, 0.6 (SD 0.4) logMAR (20/80 Snellen); IOP, 18.7 (4.9) mmHg; and number of glaucoma medications, 1.7 (0.8). Mean postoperative results were best corrected vision, 0.2 (0.4) logMAR (20/32 Snellen); IOP, 15.1 (3.2) mmHg; and number of glaucoma medications, 0.3 (0.6). Postoperatively, the mean decreases from baseline were 19.2% for IOP and 84.1% for number of glaucoma medications; 85% of eyes required fewer glaucoma medications and 78% of eyes were medication free, with IOP control. There were no significant operative or postoperative complications. Conclusion: Combined phacoemulsification and trabeculectomy with releasable sutures, in the absence of antimetabolites, is a safe, effective, and stable alternative for patients with cataracts and glaucoma. [ABSTRACT FROM AUTHOR]

The influence of metal precursor and solvent composition on the morphology of SiO2, Bi2O3, and other oxide particles made by flame spray pyrolysis (FSP) was investigated. Silica precursors with boiling pointsTbp=299–548 K dissolved in xylene were used as well as different solvents (Tbp=308–557 K) with tetraethyl-orthosilicate (TEOS) as the silica precursor. For Bi2O3, nonvolatile bismuth nitrate pentahydrate was dissolved in solvents withTbp=338–468 K. Product powders were characterized by nitrogen adsorption, X-ray diffraction, and scanning and transmission electron microscopy. From these data as well as from the literature of FSP synthesis of Bi2O3, CeO2, MgO, ZnO, Fe2O3, Y2O3, Al2O3, and Mg–Al spinel, it is inferred that hollow/inhomogeneous particles are formed at low combustion enthalpy densities and when the solvent boiling point is comparable or smaller than the precursor melting or decomposition point. [ABSTRACT FROM AUTHOR]

Deals with a study which examined the simultaneous deposition of gold nanoparticles during flame synthesis of titanium oxide and silicon oxide. Experimental details; Comparison of the gold crystallite sizes of titania and silica; Concentration of titania in the film spray pyrolysis.

Intraocular lens (IOL) implantation is now accepted as the most effective means of aphakic correction in selected patients undergoing cataract surgery. In terms of final rehabilitation, however, complications such as corneal oedema, retinal detachment, and cystoid macular oedema remain problematic. Results of prospective concurrent trials of IOL implantation performed at the Wilmer Institute are presented, with particular reference to the posterior chamber intraocular lens and with specific emphasis on postoperative complications. [ABSTRACT FROM PUBLISHER]

Four young male patients with keratoconus had traumatic dehiscence of the surgical wound after penetrating keratoplasty. Two were rendered aphakic by the trauma, and in one patient the lens was dislocated posteriorly. In each case the dehiscence was repaired by resuturing the original corneal graft. Despite marked corneal oedema in the immediate postoperative period all four grafts deturgesced and subsequently cleared. The follow-up has been a minimum of 23 months. We recommend therefore primary resuturing of traumatic wound dehiscence after keratoplasty, anterior vitrectomy if the lens dislodged, and prophylactic antibiotics postoperatively. The clearing of the initially oedematous grafts in each case illustrates the resilience of the corneal endothelium. [ABSTRACT FROM PUBLISHER]

Map-dot-fingerprint basement-membrane abnormalities of the cornea are common in the general population, affecting as many as 76% of persons over age 50 and 42% of persons of all ages. The prevalence of this condition in the general population is not significantly different from that found in families of patients with recurrent corneal erosions and map-dot-fingerprint corneal changes. Despite this extremely high prevalence of basement-membrane changes the incidence of recurrent erosive symptoms in total groups of patients with basement-membrane changes is quite rare, suggesting that these 2 entities are possibly not related. Although previous observers have suggested an autosomal dominant mode of inheritance of these basement-membrane changes, our data raise the possibility that map-dot-fingerprint basement-membrane changes represent an age-dependent, degenerative condition of the cornea. We were unable, however, to prove either hypothesis. [ABSTRACT FROM PUBLISHER]

Nocardia asteroides has been reported as the cause of keratitis in only 7 cases and of other ocular disease in another 12 cases. We report a case of N. asteroides keratitis that presented 3 weeks after rural trauma and progressed despite trials of appropriate antibiotics. Seven weeks after the origianl injury a successful conjunctival flap was placed over the cornea. The morphology and the sensitivity testing of N. asteroides to antibiotics appears necessary before reliable information can be obtained for clinical use. Moreover, our case did not show the relatively benign course of other reported cases of nocardia keratitis. [ABSTRACT FROM PUBLISHER]

Five hundred patients undergoing cataract surgery were prospectively examined, and 46 Caucasian patients were found to have strictly idiopathic cataracts severe enough to warrant surgery on or before age 55. In a masked fashion we determined the activity of galactokinase (GK) and galactose-1-phosphate uridyl transferase (GPUT) in these patients as well as on 53 age matched controls. With respect to GK no cataract patient had an enzyme level of less than 2 standard deviations below the control mean. However, 3 of 45 (6.7%) patients in the cataract group had a GPUT level less than 2 standard deviations below the mean for controls, and were presumably heterozygotes for this enzyme. In comparison with the expected population rate of 0.8% this is highly significant (p = 0.006). Abnormalities in galactose pathway enzymes may therefore predispose to development of presenile cataracts. In affected people there is a possibility of treating these patients clinically by dietary restriction of dairy products or by using aldose reductase inhibitors to prevent or reverse cataract formation. [ABSTRACT FROM PUBLISHER]

Aims: To describe a technique for posterior lamellar keratoplasty donor preparation. Methods: In an experimental study eight human donor research corneas were mounted onto an artificial anterior chamber and deep stromal pockets dissected. Four corneas were mounted in the standard endothelial side down orientation and dissected using standard instruments (group 1). Another t four corneas were mounted endothelial side up and dissected using a flat spatula (group 2). Trephined lamellar graft thickness was assessed by ultrasound pachymetry. The grafts were also analysed using vital staining of the endothelium and standard histological preparation. Results: Achieved posterior graft thickness was 118 (SD 32) μm (group 1) and 92 (23) μm (group 2) (p = 0.324). Percentage of devitalised endothelial cells was 0.86% (1.48%) (group 1) and 3.9% (23%) (group 2) (p = 0.185). The dissections using both harvesting techniques remained in plane and were smooth. Conclusions: A blunt spatula and endothelium side up orientation on an artificial anterior chamber can be used to create posterior lamellar dissections without compromising endothelial cell number or planarity when compared to standard endothelium side down harvest. [ABSTRACT FROM AUTHOR]