Bicomponent Supramolecular Architectures at the Vacuum-Solid Interface.

This review aims at giving the readers the basic concepts needed to understand two-dimensional bimolecular organizations at the vacuum-solid interface. The first part describes and analyzes molecules-molecules and molecules-substrates interactions. The current limitations and needs in the understanding of these forces are also detailed.

Sea spray aerosol as a unique source of ice nucleating particles.

Ice nucleating particles (INPs) are vital for ice initiation in, and precipitation from, mixed-phase clouds. A source of INPs from oceans within sea spray aerosol (SSA) emissions has been suggested in previous studies but remained unconfirmed. Here, we show that INPs are emitted using real wave breaking in a laboratory flume to produce SSA.

Use of PCR-RFLP Analysis to Monitor Fungicide Resistance in Cercospora beticola Populations from Sugarbeet (Beta vulgaris) in Michigan, United States.

Genetic resistance to Quinone outside inhibitor (QoI) and benzimidazole fungicides may be responsible for a recent decline in efficacy of chemical control management strategies for Cercospora leaf spot (CLS) caused by Cercospora beticola in Michigan sugarbeet (Beta vulgaris) fields. The target genes and fungicide resistance mutations are known for these two fungicides. Based on this, two standard polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assays were developed to detect the G143A and E198A point mutations in the fungal mitochondrial cytochrome b and the β-tubulin genes, respectively.

A Coordinated Effort to Manage Soybean Rust in North America: A Success Story in Soybean Disease Monitoring.

Existing crop monitoring programs determine the incidence and distribution of plant diseases and pathogens and assess the damage caused within a crop production region. These programs have traditionally used observed or predicted disease and pathogen data and environmental information to prescribe management practices that minimize crop loss. Monitoring programs are especially important for crops with broad geographic distribution or for diseases that can cause rapid and great economic losses.

How well informed are patients when leaving the emergency department? comparing information provided and information retained.

Study Objective: Patients discharged from the emergency department (ED) should be informed comprehensively and accurately about the diagnosis, future examinations and follow-up care. This study investigates: (1) how comprehensively patients are informed by physicians on discharge; (2) how accurately patients remember this information after discharge; (3) how well informed overall patients leave the ED; and (4) whether informedness relates to patient satisfaction.

Methods: This study compares: (1) information given during discharge conversations, based on audio recordings of the conversations, with (2) accuracy of patient recall of this information, based on postdischarge interviews.

Covalent networks through on-surface chemistry in ultra-high vacuum: state-of-the-art and recent developments.

The fabrication of large molecular devices, directly on surfaces in UHV conditions, by covalent coupling of smaller precursors has become in the past years an attractive solution for Molecular Electronics. This review presents the state-of-the-art and an analysis of the potential of this new field, from Ullmann type C-C coupling, cyclodehydrogenation, and reactions involving heteroelements to 2D polymerisation on insulating thin films. Mechanistic insights are also mentioned, giving preliminary explanations on the influence of the substrate and the 2D confinement.

On the origin of copper(I) catalysts from copper(II) precursors in C-N and C-O cross-couplings.

Cu(II) precursors ligated to phenanthrolines are reduced in situ by alcohols or amines in the presence of a base (Cs(2)CO(3)) to generate Cu(I) species which are active catalysts in C-N and C-O cross-coupling reactions. The conversion Cu(II) --> Cu(I) has been evidenced and monitored by UV-vis and NMR spectroscopy.

Dendritic structures within dendritic structures: dendrimer-induced formation and self-assembly of nanoparticle networks.

15-Membered tri-olefinic azamacrocycles as end-groups of phosphorus-containing dendrimers from generation 1 to 4 are used for obtaining Pt nanoparticles in mild conditions; remarkable and unprecedented branched supramolecular assemblies composed of dendrimers and coalesced Pt nanoparticles are obtained, which become larger for higher dendrimer generations, affording for the first time a very unique organization of organic dendritic structures interweaved with inorganic dendritic structures.

"Click" methodologies: efficient, simple and greener routes to design dendrimers.

Designing dendrimers that are monodisperse hyperbranched macromolecules and offer significant potential in numerous scientific fields, is becoming a major topical area in modern research. Among the challenges of the 21st century, synthetic methodologies that increase efficiency of conversion and a greener chemistry approach, are expected to lead the way in the quest to build novel nanomaterials. The recent entry of so-called "click" reactions that include Diels-Alder, Cu(I)-catalyzed Huisgen cycloaddition and thiol-ene coupling, have generated real stimulus not only in developing elegant materials of choice, but also in making the leap to industrial scale build-up of dendritic macromolecules.

Combined Cu(I)-catalysed alkyne-azide cycloaddition and furan-maleimide Diels-Alder "click" chemistry approach to thermoresponsive dendrimers.

A divergent dendrimer construction methodology that employs Cu(I)-catalysed alkyne-azide cycloaddition (CuAAC) and furan-maleimide Diels-Alder (DA) "click" chemistry in a layer-by-layer fashion, is described. This synergistic approach yields dendrimers that undergo thermal disassembly via a retro-DA reaction.

Diels-Alder "click" chemistry in designing dendritic macromolecules.

In the current decade, design of dendritic macromolecules including dendrimers and polymers has reached a new era, mainly due to the remarkably successful and elegant synthetic routes that have been developed recently. This survey aims at demonstrating the potential of the Diels-Alder "click" chemistry, a very effective, simple and versatile synthetic tool in the formation of complex and functional nanometer-sized assemblies. The role of retro Diels-Alder reaction is also explored to highlight the increasing competitive potential of this strategy in the design of dendritic macromolecules of topical interest.

Dendrimer design using Cu(I)-catalyzed alkyne-azide "click-chemistry".

The chemoselective [3+2] cycloaddition of an azide on to an alkyne, catalyzed by Cu(1), has become known as "click-chemistry". The ease with which this reaction can be carried out and the formation of pure product without the need for further purification, offer a tremendous potential in developing monodisperse 1,4-disubstituted 1,2,3-triazole heterocycle based macromolecules of a diverse nature. The versatility of this approach in designing dendrimers or functionalizing them at the periphery with desired molecules has rekindled hopes in developing nanomaterials, at scales that can accelerate their entry into industrial usage.

Optical properties of hybrid dendritic-mesoporous titania nanocomposite films.

New hybrid optical sensors have been prepared by grafting specifically designed fluorescent, functionalised, phosphorus-containing dendrimers onto a nanocrystalline mesoporous titania thin film formed by evaporation-induced self-assembly. The structural characterisation and optical behaviour of these new fluorescent probes have been studied both in solution and after being grafted onto an inorganic network, which resulted in the discovery of improved probing selectivity in the solid state. This new hybrid sensor exhibits high sensitivity to phenolic OH moieties (especially those from resorcinol and 2-nitroresorcinol), which induce the quenching of fluorescence more efficiently in the solid state than in solution.

Synthesis and properties of dendrimers possessing the same fluorophore(s) located either peripherally or off-center.

Two series of phosphorus dendrimers functionalized by maleimide derivatives are synthesized, as well as three new monomeric maleimide derivatives, of which two are characterized by X-ray diffraction. The first series of phosphorus dendrimers possesses maleimide derivatives as end groups (6-48, from generation 0 to generation 3). The second series of dendrimers possesses a single copy of the same maleimide derivative linked "off-center" to a cyclotriphosphazene core, leading to dissymmetrical dendrimers; this series is synthesized from generation 0 to generation 2.

Persistence and Latency of Clavibacter michiganensis subsp. sepedonicus in Field-Grown Seed Potatoes.

Whole seed tubers were inoculated with different inoculum doses of Clavibacter michiganensis subsp. sepedonicus and planted in the field. Ring rot symptom development and the persistence of C.

First Report of Leaf and Stem Rust Caused by Puccinia sherardiana on Sphaeralcea grossulariaefolia in North America and S. munroana in Wyoming.

Diseased samples of globe mallow, Sphaeralcea grossulariaefolia and S. munroana, were submitted by an ornamental seed producer in Wyoming to our Extension Plant Pathology Laboratory in July 1997. Dark brown, amphigenous telia surrounded by chlorotic halos were present on both foliage and stems.

Sequence analysis of the cDNA encoding the precursor of equinatoxin V, a newly discovered hemolysin from the sea anemone Actinia equina.

A cDNA encoding the 214-amino-acid (aa) precursor of equinatoxin V (EqtV) has been isolated from an Actinia equina cDNA library. The sequence of the mature toxin is preceded, as that of EqtII, by a signal peptide of 19 aa and a hydrophilic propeptide of 16 aa ending with a pair of basic residues. This is similar to the precursors of calitoxins from another sea anemone Calliactis parasitica and to those of some antimicrobial peptides of the magainin and dermaseptin families from vertebrates.