Polydopamine-mediated immobilization of alginate lyase to prevent P. aeruginosa adhesion

Given alginate’s contribution to Pseudomonas aeruginosa virulence, it has long been considered a promising target for interventional therapies, which have been performed by using the enzyme alginate lyase. In this work, instead of treating pre-established mucoid biofi lms, alginate lyase is immobilized onto a surface as a preventive measure against P. aeruginosa adhesion. A polydopamine dip-coating strategy is employed for functionalization of polycarbonate surfaces. Enzyme immobilization is confi rmed by surface characterization. Surfaces functionalized with alginate lyase exhibit anti-adhesive properties, inhibiting the attachment of the mucoid strain. Moreover, surfaces modifi ed with this enzyme also inhibit the adhesion of the tested non-mucoid strain. Unexpectedly, treatment with heat-inactivated enzyme also inhibits the attachment of mucoid and non-mucoid P. aeruginosa strains. These fi ndings suggest that the antibacterial performance of alginate lyase functional coatings is catalysis-independent, highlighting the importance of further studies to better understand its mechanism of action against P. aeruginosa strains.T he authors acknowledge the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684). This study was also supported by FCT and the European Community fund FEDER, through Program COMPETE, under the scope of the Projects “PTDC/SAU-SAP/113196/2009” (FCOMP-01-0124-FEDER-016012) and “RECI/BBB-EBI/0179/2012” (FCOMP-01-0124-FEDER-027462). The authors also acknowledge Dr. Margarida Martins from 3B’s Research Group – Biomaterials, Biodegradables and Biomimetics, University of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative Medicine (AvePark, 4806-909 Taipas/Guimarãe s, Portugal) for kindly providing the isolated strains which were obtained under the scope of the project “Insights into peritoneal dialysis catheter associated biofi lms” funded by the Portuguese Society of Nephrology to Dr. Anabela Rodrigues. The authors also acknowledge the Ph.D. Grant of Diana Alves (SFRH/BD/78063/2011). T.S.S. was funded by a National Science Foundation graduate fellowship (Grant No. GRFP 2011124091), the Ryan Fellowship of Northwestern University, and NIH grant R37 DE014193 to P.B.M

Monocot and dicot genes encoding the small subunit ofribulose-1,5-bisphosphate carboxylase : structural analysis and gene expression

Richard Broglie, Gloria Coruzzi, Gayle Lamppa, Brian Keith,and Nam- Hai Chua, Laboratory of Plant Molecular Biology, The Rockefeller University, New York, New York

Fielding the magnetically applied pressure-shear technique on the Z accelerator (completion report for MRT 4519).

The recently developed Magnetically Applied Pressure-Shear (MAPS) experimental technique to measure material shear strength at high pressures on magneto-hydrodynamic (MHD) drive pulsed power platforms was fielded on August 16, 2013 on shot Z2544 utilizing hardware set A0283A. Several technical and engineering challenges were overcome in the process leading to the attempt to measure the dynamic strength of NNSA Ta at 50 GPa. The MAPS technique relies on the ability to apply an external magnetic field properly aligned and time correlated with the MHD pulse. The load design had to be modified to accommodate the external field coils and additional support was required to manage stresses from the pulsed magnets. Further, this represents the first time transverse velocity interferometry has been applied to diagnose a shot at Z. All subsystems performed well with only minor issues related to the new feed design which can be easily addressed by modifying the current pulse shape. Despite the success of each new component, the experiment failed to measure strength in the samples due to spallation failure, most likely in the diamond anvils. To address this issue, hydrocode simulations are being used to evaluate a modified design using LiF windows to minimize tension in the diamond and prevent spall. Another option to eliminate the diamond material from the experiment is also being investigated

Resolving fundamental limits of adhesive bonding in microfabrication.

As electronic and optical components reach the micro- and nanoscales, efficient assembly and packaging require the use of adhesive bonds. This work focuses on resolving several fundamental issues in the transition from macro- to micro- to nanobonding. A primary issue is that, as bondline thicknesses decrease, knowledge of the stability and dewetting dynamics of thin adhesive films is important to obtain robust, void-free adhesive bonds. While researchers have studied dewetting dynamics of thin films of model, non-polar polymers, little experimental work has been done regarding dewetting dynamics of thin adhesive films, which exhibit much more complex behaviors. In this work, the areas of dispensing small volumes of viscous materials, capillary fluid flow, surface energetics, and wetting have all been investigated. By resolving these adhesive-bonding issues, we are allowing significantly smaller devices to be designed and fabricated. Simultaneously, we are increasing the manufacturability and reliability of these devices

Molecular characterization and genetic mapping of DNA sequences encoding the Type I chlorophyll a/b-binding polypeptide of photosystem I in Lycopersicon esculentum (tomato)

We report the isolation and characterization of a tomato nuclear gene encoding a chlorophyll a/b-binding (CAB) protein of photosystem I (PSI). The coding nucleotide sequence of the gene, designated Cab -6B, is different at eight positions from that of a previously isolated cDNA clone derived from the Cab -6A gene, but the two genes encode identical proteins. Sequence comparison with the cDNA clone revealed the presence of three short introns in Cab -6B. Genetic mapping experiments demonstrate that Cab -6A and Cab -6B are tightly linked and reside on chromosome 5, but the physical distance between the two genes is at least 7 kilobases. Cab -6A and Cab -6B have been designated Type I PSI CAB genes. They are the only two genes of this branch of the CAB gene family in the tomato genome, and they show substantial divergence to the genes encoding CAB polypeptides of photosystem II. The Type I PSI CAB genes, like the genes encoding PSII CAB proteins, are highly expressed in illuminated leaf tissue and to a lesser extent in other green organs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43459/1/11103_2004_Article_BF00166457.pd