A self-healable fluorescence active hydrogel based on ionic block copolymers prepared via ring opening polymerization and xanthate mediated RAFT polymerization

YesIn this work we report a facile method to prepare a fluorescence active self-healable hydrogel via incorporation of fluorescence responsive ionic block copolymers (BCPs). Ionic block copolymers were prepared via a combined effect of ring opening polymerization (ROP) of ε-caprolactone and xanthate mediated reversible addition–fragmentation chain transfer (RAFT) polymerization. Here polycaprolactone (PCL) was modified with xanthate to prepare a PCL based macro-RAFT agent and then it was utilized to prepare block copolymers with cationic poly(2-(methacryloyloxy)ethyltrimethyl ammonium chloride) (PCL-b-PMTAC) and anionic poly(sodium 4-vinylbenzenesulfonate) (PCL-b-PSS). During the block formation, the cationic segments were randomly copolymerized with a trace amount of fluorescein O-acrylate (FA) (acceptor) whereas the anionic segments were randomly copolymerized with a trace amount of 9-anthryl methylmethacrylate (AMMA) (donor) to make both the segments fluorescent. The block copolymers form micelles in a DMF : water mixture (1 : 4 volume ratio). The ionic interaction of two BCPs was monitored via Förster resonance energy transfer (FRET) and zeta potential measurements. The oppositely charged BCPs were incorporated into a polyacrylamide (PAAm) based hydrogel that demonstrated self-healing behavior and is also highly fluorescent.IIT Kharagpur and MRC (MR/N501888/2

Current practices in spatial analysis of cancer data: mapping health statistics to inform policymakers and the public

BACKGROUND: To communicate population-based cancer statistics, cancer researchers have a long tradition of presenting data in a spatial representation, or map. Historically, health data were presented in printed atlases in which the map producer selected the content and format. The availability of geographic information systems (GIS) with comprehensive mapping and spatial analysis capability for desktop and Internet mapping has greatly expanded the number of producers and consumers of health maps, including policymakers and the public. Because health maps, particularly ones that show elevated cancer rates, historically have raised public concerns, it is essential that these maps be designed to be accurate, clear, and interpretable for the broad range of users who may view them. This article focuses on designing maps to communicate effectively. It is based on years of research into the use of health maps for communicating among public health researchers. RESULTS: The basics for designing maps that communicate effectively are similar to the basics for any mode of communication. Tasks include deciding on the purpose, knowing the audience and its characteristics, choosing a media suitable for both the purpose and the audience, and finally testing the map design to ensure that it suits the purpose with the intended audience, and communicates accurately and effectively. Special considerations for health maps include ensuring confidentiality and reflecting the uncertainty of small area statistics. Statistical maps need to be based on sound practices and principles developed by the statistical and cartographic communities. CONCLUSION: The biggest challenge is to ensure that maps of health statistics inform without misinforming. Advances in the sciences of cartography, statistics, and visualization of spatial data are constantly expanding the toolkit available to mapmakers to meet this challenge. Asking potential users to answer questions or to talk about what they see is still the best way to evaluate the effectiveness of a specific map design

Retroperitoneal cystic lymphangioma

A case of a large retroperitoneal tumor in a previously asymptomatic twenty-two-year-old white female is presented. A review of the literature confirms the rarity of this tumor. Its histologic and embryologic derivation as well as its subtle and bizarre method of presentation are discussed. The cause of such lesions is debatable, but primary cure can be accomplished by meticulous excision of the lesion or marsupialization. This seldom seen neoplasm must enter into the differential diagnosis of all retroperitoneal masses.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/22183/1/0000614.pd

Core (Polystyrene)−Shell [Poly(glycerol monomethacrylate)] Particles

YesA set of water-swollen core−shell particles was synthesized by emulsion polymerization of a 1,3-dioxolane functional monomer in water. After removal of the 1,3- dioxolane group, the particles’ shells were shown to swell in aqueous media. Upon hydrolysis, the particles increased in size from around 70 to 100−130 nm. A bicinchoninic acid assay and ζ-potential measurements were used to investigate the adsorption of lysozyme, albumin, or fibrinogen. Each of the core−shell particles adsorbed significantly less protein than the noncoated core (polystyrene) particles. Differences were observed as both the amount of difunctional, cross-linking monomer and the amount of shell monomer in the feed were changed. The core−shell particles were shown to be resistant to protein adsorption, and the degree to which the three proteins adsorbed was dependent on the formulation of the shell.EPSRC and MR

Highly-branched poly(N-isopropyl acrylamide) functionalised with pendant Nile red and chain end vancomycin for the detection of Gram-positive bacteria

YesThis study shows how highly branched poly(N-isopropyl acrylamide) (HB-PNIPAM) with a chain pendant solvatochromic dye (Nile red) could provide a fluorescence signal, as end groups bind to bacteria and chain segments become desolvated, indicating the presence of bacteria. Vancomycin was attached to chain ends of HB-PNIPAM or as pendant groups on linear polymers each containing Nile red. Location of the dye was varied between placement in the core of the branched polymer coil or the outer domains. Both calorimetric and fluorescence data showed that branched polymers responded to binding of both the peptide target (D-Ala-D-Aa) and bacteria in a different manner than analogous linear polymers; binding and response was more extensive in the branched variant. The fluorescence data showed that only segments located in the outer domains of branched polymers responded to binding of Gram-positive bacteria with little response when linear analogous polymer or branched polymer with the dye in the inner core was exposed to Staphylococcus aureus.Innovate UK/Smith and Nephew Ltd. (UK) (TSB 103988) and by MRC (MR/N501888/2)

Atmospheric Response to the North Pacific Enabled by Daily Sea Surface Temperature Variability

Ocean–atmosphere interactions play a key role in climate variability on a wide range of time scales from seasonal to decadal and longer. The extratropical oceans are thought to exert noticeable feedbacks on the atmosphere especially on decadal and longer time scales, yet the large-scale atmospheric response to anomalous extratropical sea surface temperature (SST) is still under debate. Here we show, by means of dedicated high-resolution atmospheric model experiments, that sufficient daily variability in the extratropical background SST needs to be resolved to force a statistically significant large-scale atmospheric response to decadal North Pacific SST anomalies associated with the Pacific Decadal Oscillation (PDO), which is consistent with observations. The large-scale response is mediated by atmospheric eddies. This implies that daily extratropical SST fluctuations must be simulated by the ocean components and resolved by the atmospheric components of global climate models to enable realistic simulation of decadal North Pacific sector climate variability

Binding of bacteria to poly (N-isopropylacrylamide) modified with vancomycin: Comparison of behavior of linear and highly branched polymers

YesThe behavior of a linear copolymer of N-isopropyl acrylamide with pendant vancomycin functionality was compared to an analogous highly branched copolymer with vancomycin functionality at the chain ends. Highly branched poly(N-isopropylacrylamide) modified with vancomycin (HB-PNIPAM-van) was synthesized by functionalization of the HB-PNIPAM, prepared using reversible addition-fragmentation chain transfer polymerization. Linear PNIPAM with pendant vancomycin functionality (L-PNIPAM-van) was synthesized by functionalization of poly(N-isopropyl acrylamide-co-vinyl benzoic acid). HB-PNIPAM-van aggregated S. aureus effectively whereas the L-PNIPAM-van polymer did not. It was found that when the HB-PNIPAM-van was incubated with S. aureus the resultant phase transition provided an increase in the intensity of fluorescence of a solvatochromic dye, nile red, added to the system. In contrast, a significantly lower increase in fluorescence intensity was obtained when L-PNIPAM-van was incubated with S. aureus. These data showed that the degree of desolvation of HB-PNIPAM-van was much greater than the desolvation of the linear version. Using microCalorimetry it was shown that there were no significant differences in the affinities of the polymer ligands for D-Ala-D-Ala and therefore differences in the interactions with bacteria were associated with changes in the probability of access of the polymer bound ligands to the D-Ala-D-Ala dipeptide. The data support the hypothesis that generation of polymer systems that respond to cellular targets, for applications such as cell targeting, detection of pathogens etc., requires the use of branched polymers with ligands situated at the chain ends.MR

Further Studies of Bolivian Crocidolite –Part IV: Fibre Width, Fibre Drift and their relation to Mesothelioma Induction: Preliminary Findings

Background The hypothesis that fibre width is a major determinant of mesothelioma induction has been examined by comparative studies of two crocidolites from different sources. Fine fibres fromCapesouthAfricaand the thicker fibre found and used similarly inBolivia.   It is well established that ‘thin’ fibre crocidolite fromCapeSouth Africais extremely mesotheliomagenic. Bolivian crocidolite has a much wider width distribution and relatively little mesothelioma inducing potential.   Methods We analysed the mesothelioma demography inBoliviawhere local crocidolite has been used for decades This was compared with the mesothelioma demography in theItalianCityof Casale Monteferrato whereCapecrocidolite was processed for many decades in the Eternit Asbestos Cement plant producing numerous cases of mesothelioma. We also conducted a limited downwind study from the fiberizing part of the historical operating plant where products containing Bolivian crocidolite were made for sale and use inCochabamba.   Results The demographic study confirmed the absence of a significant mesothelioma excess inBolivia. Despite the extremely high fibre concentrations measured in the plant, no significant fibre levels were detected 100 meters away.   Conclusion These preliminary findings undermine claims such as those made at Casale that crocidolite fibre can drift up to 15 km and remain airborne in quantities sufficient to contribute significantly to mesothelioma induction.   We propose the difference in thickness and the attendant reduction in the percentage ofStantonfibres provides an explanation for the difference in mesothelioma patterns found in each city