Monolayers of Carbohydrate-Containing Lipids at the Water- Air Interface

Glycolipids are important members of the glycoconjugate family that are distributed on cell surfaces and are important in aspects of cellular behavior including signal transduction, protein trafficking, cell surface recognition and cell adhesion. Errors in the synthesis or mutations of these glycoconjugates are often linked with various human pathological conditions. The complex nature of their molecular structures coupled with the complexity of cellular structure make their study a challenging process, which can be simplified by fabrication of model membrane systems. Liposomes and monolayers of lipids at the air-water interface are two of the most frequently used model membrane systems. Techniques for fabrication of monolayer models and methods used for their studies are discussed with a focus on glycolipids

Electrodeposition of Nanoporous Gold Thin Films

Nanoporous gold (NPG) films have attracted increasing interest over the last ten years due to their unique properties of high surface area, high selectivity, and electrochemical activity along with enhanced electrical conductivity, and chemical stability. A variety of fabrication techniques to synthesize NPG thin films have been explored so far including dealloying, templating, sputtering, self-assembling, and electrodeposition. In this review, the progress in the synthetic techniques over the last ten years to prepare porous gold films has been discussed with emphasis given on the technique of electrodeposition. Such films have wide-ranging applications in the fields of drug delivery, energy storage, heterogeneous catalysis, and optical sensing

Self‐Assembled Monolayers of Carbohydrate Derivatives on Gold Surfaces

Self‐assembled monolayers (SAMs) presenting carbohydrates (glycans) have been widely prepared on gold surfaces to mimic the carbohydrate surfaces that are involved in molecular recognition phenomena in living cells. The binding affinity of carbohydrate immbolized on SAM surfaces to various carbohydrate‐binding proteins (such as lectins) can be studied by optical, electrochemical, piezoelectrical and thermal sensing techniques. The lectins present on the surface of pathogens (e.g., bacteria or viruses) can be used as targets for capturing onto carbohydrates immobilized on SAM surfaces. The immobilized carbohydrates can also be used for detecting different types of disease biomarkers present in bodily fluids. Synergistic properties of carbohydrate SAMs and gold nanoparticles can be used for vaccine preparation and drug delivery. By studying different types of glycans, their properties, and the behavior toward recognition of specific pathogens and biomarkers, we can develop not only new therapeutics but also enhance the diagnostic strategies of various diseases. In this chapter, we discuss carbohydrate‐terminated SAMs and their common preparation strategies. Next, we focus on roles of different components of SAMs, characterization techniques, and applications

Structure and Applications of Gold in Nanoporous Form

Nanoporous gold (np-Au) has many interesting and useful properties that make it a material of interest for use in many technological applications. Its biocompatible nature and ability to serve as a support for self-assembled monolayers of alkanethiols and their derivative make it a suitable support for the immobilization of carbohydrates, enzymes, proteins, and DNA. Its chemically inert, physically robust and conductive high-surface area makes it useful for the design of electrochemistry-based chemical/bio-sensors and reactors. Furthermore, it is also used as solid support for organic molecular synthesis and biomolecules separation. Its enhanced optical property has application in design of plasmonics-based sensitive biosensors. In fact, np-Au is one of the few materials that can be used as a transducer for both optical and electrochemical biosensing. Due to the presence of low-coordination surface sites, np-Au shows remarkable catalytic activity for oxidation of molecules like carbon monoxide and methanol. Owing to the importance of np-Au, in this chapter we will highlight different strategies of fabrication of np-Au and its emerging applications based on its unique properties

IRISS (Increasing Resilience in Surveillance Societies) FP7 European Research Project, Deliverable 3.2: Surveillance Impact Report

External research report produced for the European Commission as part of the FP7 IRISS project: Increasing Resilience in Surveillance Socieities, containing European case studies on the varying formats of neighbourhood watch, including the cultural and historical factors which may influence the creation of neighbourhood watch groups in the first instance. Overview of neighbourhood watch in the United Kingdom and analysis of the changing role of the police in relation to community policing and the impact which this has had on the primary purpose of neighbourhood watch organisations.This deliverable was written as part of the IRISS project which received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under Grant Agreement No. 285593. Additional co-authors: Alessia Ceresa, Chiara Fonio, Walter Peissl, Robert Rothman, Jaro Sterbik Lamina, Ivan Szekely, Beatrix Vissy, Wolfgang Bonß, Daniel Fischer, Gemma Galdon Clavell, Reinhard Kreissl, Alexander Neumann, Nils Zurawsk

Passive Multiplexer Test Structure For Fast and Accurate Contact and Via Fail-Rate Evaluation

Abstract-Complexity of integrated circuits has led to millions of contacts and vias on every chip. To allow accurate yield evaluation, it is required to determine fail rates of 10 faults per billion, which requires test structures with huge chains of 1 million or more contacts and vias. At the same time, contacts and vias are getting smaller, and thus their resistance is increasing for every new technology node. Consequently, the resistance of such chains becomes impossible to measure. To overcome this limit without increasing the number of measurement pads, we are proposing a passive multiplexer array of via chains, which breaks up a huge contact-via chain in many individually measurable subchains. Accuracy of fail rates will be increased since the fail rate can be determined based on many subchains, instead of being determined based on only one huge chain. Furthermore, this test structure better supports failure analysis since it is faster to locate a faulty contact or via. No additional devices or process steps are required which allows implementation as short flows for fast process problem debugging

Robust reduction of graphene fluoride using an electrostatically biased scanning probe

ABSTRACT We report a novel and easily accessible method to chemically reduce graphene fluoride (GF) sheets with nanoscopic precision using high electrostatic fields generated between an atomic force microscope (AFM) tip and the GF substrate. Reduction of fluorine by the electric field produces graphene nanoribbons (GNR) with a width of 105-1,800 nm with sheet resistivity drastically decreased from >1 TΩ·sq. -1 (GF) down to 46 kΩ·sq. -1 (GNR). Fluorine reduction also changes the topography, friction, and work function of the GF. Kelvin probe force microscopy measurements indicate that the work function of GF is 180-280 meV greater than that of graphene. The reduction process was optimized by varying the AFM probe velocity between 1.2 μm·s -1 and 12 μm·s -1 and the bias voltage applied to the sample between -8 and -12 V. The electrostatic field required to remove fluorine from carbon is ~1.6 V·nm -1 . Reduction of the fluorine may be due to the softening of the C-F bond in this intense field or to the accumulation and hydrolysis of adventitious water into a meniscus

Last millennium northern hemisphere summer temperatures from tree rings: Part I: The long term context

Large-scale millennial length Northern Hemisphere (NH) temperature reconstructions have been progressively improved over the last 20 years as new datasets have been developed. This paper, and its companion (Part II, Anchukaitis et al. in prep), details the latest tree-ring (TR) based NH land air temperature reconstruction from a temporal and spatial perspective. This work is the first product of a consortium called N-TREND (Northern Hemisphere Tree-Ring Network Development) which brings together dendroclimatologists to identify a collective strategy for improving large-scale summer temperature reconstructions. The new reconstruction, N-TREND2015, utilises 54 records, a significant expansion compared with previous TR studies, and yields an improved reconstruction with stronger statistical calibration metrics. N-TREND2015 is relatively insensitive to the compositing method and spatial weighting used and validation metrics indicate that the new record portrays reasonable coherence with large scale summer temperatures and is robust at all time-scales from 918 to 2004 where at least 3 TR records exist from each major continental mass. N-TREND2015 indicates a longer and warmer medieval period (∼900–1170) than portrayed by previous TR NH reconstructions and by the CMIP5 model ensemble, but with better overall agreement between records for the last 600 years. Future dendroclimatic projects should focus on developing new long records from data-sparse regions such as North America and eastern Eurasia as well as ensuring the measurement of parameters related to latewood density to complement ring-width records which can improve local based calibration substantially