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The bonding and self-assembly of a chirally organized monolayer of alanine on the Cu(110) surface has been investigated using reflection-absorption infrared spectroscopy, low-energy electron diffraction (LEED), and scanning tunneling microscopy (STM). This multitechnique approach has enabled an in-depth understanding of the hierarchy of chirality transfer: from a single adsorbed molecule, to size-defined chiral clusters, and then to an overall chiral assembly. The data have indicated that the alanine is in its anionic form, bound to the copper surface through the oxygens of the ionized carboxylate group and the nitrogen of the neutral amino group. Importantly, the methyl group is held away from the surface, resulting in direct chirality transfer into the footprint of the adsorbed alanine molecules, with the local adsorption motif for S-alanine being the mirror image of that created for R-alanine. STM has shown that S-alanine molecules self-organize to form size-defined chiral clusters of six or eight molecules at the surface, interspersed with chiral channels of bare metal. Together, these clusters and channels further self-assemble into a chiral array with one unique chiral domain sustained across the entire surface. A similar chiral assembly, but with the mirror organization, has been observed for R-alanine. Structural models for the individual clusters are proposed, and in conjunction with LEED data, overall models for these chiral phases of both S- and R-alanine have been constructed. Overall, this adsorption system has been found to be both strongly chemisorbed and capable of extensive intermolecular H-bonding, causing stresses that lead not only to the chiral self-organization of molecules but also to a specific self-organization of the empty chiral channels and spaces that intersperse the structure which, in turn, chirally assemble across macroscopic length scales to give a surface with global organizational chirality.

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Sudden infant death syndrome (SIDS) accounts for the largest number of deaths during the first year of life in developed countries. The possible causes of SIDS are numerous and, to date, there is no adequate unifying pathological explanation for SIDS. Epidemiological studies have played a key role in identifying risk factors, knowledge of which has underpinned successful preventive programmes. This review critically assesses information on the main risk factors and causal hypotheses put forward for SIDS, focusing on research published since 1994. The overall picture that emerges from this review is that affected infants are not completely normal in development, but possess some inherent weakness, which may only become obvious when the infant is subjected to stress. Initially there may be some minor impairment or delay in development of respiratory, cardiovascular or neuromuscular function. None of these is likely to be sufficient, in isolation, to cause death and, provided the infant survives the first year of life, may no longer be of any significance. However, when a compromised infant is confronted with one or more stressful situations, several of which are now clearly identified as risk factors, and from which the majority of infants would normally escape, the combination may prove fatal.

The behavior of the tripeptides tri-L-alanine and tri-L-leucine, deposited under ultrahigh vacuum conditions onto a clean Cu{110} surface, has been studied using reflection-absorption infrared spectroscopy and low-energy electron diffraction. Both peptides remain intact upon landing on the Cu{110}surface and are present in their anionic form. Bonding to the surface is through the terminal carboxylate ions (COO -) and amino groups (NH2) with the CdO functionalities of the amide groups (CONH) also involved in the process.Tri-L-alanine shows a complex range of adsorption phases which are sensitive to growth conditions. At high flux and with the substrate held at room temperature (300 K), three phases are identified. Phase I occurs at low coverage with tri-L-alanine molecules randomly adsorbed and isolated from each other. As coverage increases, phase II is formed which represents a monolayer with intermolecular hydrogen bonding occurring across the surface. At higher coverages, a saturated bilayer, phase III, is created with the perpendicularly oriented CdO functionalities of the amide groups being involved in strong interlayer H-bonding. There is evidence that, locally, phase III has strong similarities to the antiparallel -sheet form of the solid crystal although no long range ordered surface structures are seen. Multilayers are formed under high flux conditions when the Cu{110} surface is cooled to 83 K. Tri-L-leucine bonds to the surface with its longer, bulkier side chains aligned along the surface normal which sterically inhibit phase III bilayer growth. Under low flux conditions, both molecules reorient after initial adsorption so that their amide CdO functionalities are more flat lying, possibly chelating to the surface, making it difficult to grow higher coverage phases.