ORIENTATION-SPECIFIC IMMOBILIZATION OF BMP-2 ON PLGA SCAFFOLDS

A variety of synthetic bone graft materials such as the polymer poly(lactic-co-glycolic acid) (PLGA) have been investigated as alternatives to current tissue based bone graft materials. In this study, efforts have been made to improve the tissue-PLGA interface by immobilizing bone morphogenetic protein-2 (BMP-2) in an oriented manner on scaffolds using covalently immobilized heparin. The results demonstrated a four-fold increase in covalently immobilized heparin compared to non-specific heparin attachment. Furthermore, the scaffolds with covalently attached heparin retained approximately three-fold more BMP-2 than did either scaffolds with no heparin attached or scaffolds with non-specific heparin attachment. The activity of scaffolds with BMP-2 immobilized in various manners was examined using an alkaline phosphatase assay on C3H10T1/2-seeded scaffolds. These results indicated approximately twice the amount of activity with scaffolds that had BMP-2 immobilized with covalently attached heparin than on scaffolds with adsorption of BMP-2 and a three-fold increase in activity when compared to scaffolds that had non-specific heparin attachment as the mechanism for BMP-2 immobilization. These results demonstrated that PLGA with covalently linked heparin has potential to immobilize BMP-2 in a specific orientation that is favorable for cell-receptor binding, leading to the more efficient use of the bone-growth factor

Elucidation of the Mode of Action of a New Antibacterial Compound Active against Staphylococcus aureus and Pseudomonas aeruginosa.

Nosocomial and community-acquired infections caused by multidrug resistant bacteria represent a major human health problem. Thus, there is an urgent need for the development of antibiotics with new modes of action. In this study, we investigated the antibacterial characteristics and mode of action of a new antimicrobial compound, SPI031 (N-alkylated 3, 6-dihalogenocarbazol 1-(sec-butylamino)-3-(3,6-dichloro-9H-carbazol-9-yl)propan-2-ol), which was previously identified in our group. This compound exhibits broad-spectrum antibacterial activity, including activity against the human pathogens Staphylococcus aureus and Pseudomonas aeruginosa. We found that SPI031 has rapid bactericidal activity (7-log reduction within 30 min at 4x MIC) and that the frequency of resistance development against SPI031 is low. To elucidate the mode of action of SPI031, we performed a macromolecular synthesis assay, which showed that SPI031 causes non-specific inhibition of macromolecular biosynthesis pathways. Liposome leakage and membrane permeability studies revealed that SPI031 rapidly exerts membrane damage, which is likely the primary cause of its antibacterial activity. These findings were supported by a mutational analysis of SPI031-resistant mutants, a transcriptome analysis and the identification of transposon mutants with altered sensitivity to the compound. In conclusion, our results show that SPI031 exerts its antimicrobial activity by causing membrane damage, making it an interesting starting point for the development of new antibacterial therapies

Social Media, Gender and the Mediatisation of War: Exploring the German Armed Forces’ Visual Representation of the Afghanistan Operation on Facebook

Studies on the mediatisation of war point to attempts of governments to regulate the visual perspective of their involvements in armed conflict – the most notable example being the practice of ‘embedded reporting’ in Iraq and Afghanistan. This paper focuses on a different strategy of visual meaning-making, namely, the publication of images on social media by armed forces themselves. Specifically, we argue that the mediatisation of war literature could profit from an increased engagement with feminist research, both within Critical Security/Critical Military Studies and within Science and Technology Studies that highlight the close connection between masculinity, technology and control. The article examines the German military mission in Afghanistan as represented on the German armed forces’ official Facebook page. Germany constitutes an interesting, and largely neglected, case for the growing literature on the mediatisation of war: its strong antimilitarist political culture makes the representation of war particularly delicate. The paper examines specific representational patterns of Germany’s involvement in Afghanistan and discusses the implications which arise from what is placed inside the frame of visibility and what remains out of its view

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A variety of synthetic bone graft materials such as the polymer poly(lactic-co-glycolic acid) (PLGA) have been investigated as alternatives to current tissue based bone graft materials. In this study, efforts have been made to improve the tissue-PLGA interface by immobilizing bone morphogenetic protein-2 (BMP-2) in an oriented manner on scaffolds using covalently immobilized heparin. The results demonstrated a four-fold increase in covalently immobilized heparin compared to non-specific heparin attachment. Furthermore, the scaffolds with covalently attached heparin retained approximately threefold more BMP-2 than did either scaffolds with no heparin attached or scaffolds with non-specific heparin attachment. The activity of scaffolds with BMP-2 immobilized in various manners was examined using an alkaline phosphatase assay on C3H10T1/2seeded scaffolds. These results indicated approximately twice the amount of activity with scaffolds that had BMP-2 immobilized with covalently attached heparin than on scaffolds with adsorption of BMP-2 and a three-fold increase in activity when compared to scaffolds that had non-specific heparin attachment as the mechanism for BMP-2 immobilization. These results demonstrated that PLGA with covalently linked heparin has potential to immobilize BMP-2 in a specific orientation that is favorable for cellreceptor binding, leading to the more efficient use of the bone-growth factor

S2−S0S_{2} - S_{0} FLUOORESCENCE, MOLECULAR STRUCTRRE, AN INITIO CALCULATIONS, AND QUKANTUM BEAT SPECTROSCOPY OF SILYLIDENE (H2C=Si)(H_{2}C=Si)

Author Institution: Department of Chemistry, University of KentuckyStrong $S_{2}-S_{0}$ fluorescence has been observed in LIF spectra of jet-cooled silylidene, $H_{2}C=Si$, produced by fragmentation of tetramethylsilane in a pulsed discharge jet. The experimental ground and excited state molecular structures have been obtained for the first time from rotational analyses of the $0^{0}_{0}$ bands of $H_{2}C =$Si and $D_{2}C=Si$. These bands exhibit pronounced rotational level intensity anomalies indicative of nonradiative decay processes. Quantum beats are observed in the fluorescence decay of almost every rotational level in $v^{\prime} = 0$ and in most of the higher vibrational levels. Fourier transforms of the beat patterns show line broadening and splitting at small magnetic fields of 10-70 Gauss. High quality ab initio studies have been done to locate the interacting electronic states and predict their vibrational frequencies and molecular structures

A revised subtribal classification of Gnaphalieae (Asteraceae)

Gnaphalieae are one of the larger tribes of the daisy family Asteraceae (Compositae) with c. 2100 species in 178 genera, occurring globally across a wide range of temperate habitats. Recent years have seen considerable advances in our understanding of their phylogenetics and evolution, but there is no widely accepted, stable subtribal classification. The present paper summarises the taxonomic history and presents the various major clades that have been named informally in phylogenetic studies. We also provide the most comprehensive phylogenetic analysis of DNA sequence data to date, including over 1000 species. Based on published studies and our new phylogenetic analyses, we suggest a subdivision of the tribe into two subtribes. These are a largely African-endemic Relhaniinae (124 species in 11 genera) and a much enlarged Gnaphaliinae, the latter accounting for more than 90% of the species diversity (c. 2000 species in 167 genera). Although a finer division of Gnaphaliinae sensu amplo may be desirable, there are at present several obstacles to such a classification, in particular contradictory or ambiguous inferences of relationships.Fil: Smissen, Rob D.. Manaaki Whenua Landcare Research; Nueva ZelandaFil: Bayer, Randall J.. University of Memphis; Estados UnidosFil: Bergh, Nicola G.. University of Cape Town; Sudáfrica. Kirstenbosch National Botanical Gardens; SudáfricaFil: Breitwieser, Ilse. Manaaki Whenua Landcare Research; Nueva ZelandaFil: Freire, Susana Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; ArgentinaFil: Galbany Casals, Mercè. Universitat Autònoma de Barcelona; EspañaFil: Schmidt Lebuhn, Alexander N.. Commonwealth Scientific and Industrial Research Organisation; AustraliaFil: Ward, Josephine M.. University of Canterbury; Nueva Zeland