Publisher Correction: Imaging single glycans.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Imaging single glycans.

Imaging of biomolecules guides our understanding of their diverse structures and functions1,2. Real-space imaging at sub-nanometre resolution using cryo-electron microscopy has provided key insights into proteins and their assemblies3,4. Direct molecular imaging of glycans-the predominant biopolymers on Earth, with a plethora of structural and biological functions5-has not been possible so far6. The inherent glycan complexity and backbone flexibility require single-molecule approaches for real-space imaging. At present, glycan characterization often relies on a combination of mass spectrometry and nuclear magnetic resonance imaging to provide insights into size, sequence, branching and connectivity, and therefore requires structure reconstruction from indirect information7-9. Here we show direct imaging of single glycan molecules that are isolated by mass-selective, soft-landing electrospray ion beam deposition and imaged by low-temperature scanning tunnelling microscopy10. The sub-nanometre resolution of the technique enables the visualization of glycan connectivity and discrimination between regioisomers. Direct glycan imaging is an important step towards a better understanding of the structure of carbohydrates.

[The risk of vibrations to the hand-arm system and cumulative trauma disorders in shoe manufacturing: a clinical case report]. / Rischio da vibrazioni al sistema mano-braccio e cumulative trauma disorders nel settore calzaturiero: descrizione di un caso clinico.

The article reports the case of a woman working in a shoe factory who had been using vibrating tools for 5 years. Because of paresthesia in her left hand, in 1989 she underwent various diagnostic trials that revealed an initial carpal tunnel syndrome of the left wrist and a homolateral epicondylitis. Measurement of the vibrations transmitted to the hand from the vibrating tool confirmed the probability of a high risk of exposure for the hand-arm system. Such adverse effects have been described by British authors as "cumulative trauma disorders" and were confirmed in this study. The importance of further studies aimed at estimating the type and degree of exposure to vibrations in shoe manufacturing workers is stressed.

[Electromyography of those exposed to vibration]. / Elettromiografia negli esposti a vibrazioni.

Electrophysiological findings in the median and ulnar nerves of a group of ten workers who operate hand-held vibrating power tools are described. Motor conduction velocities, motor latencies and amplitude of evoked compound muscle action potentials were measured. We have observed statistically significant changes in the distal latencies and in the amplitude of evoked compound muscle action potentials of median nerves in all the subjects examined, whereas the motor conduction velocities were normal in both median and ulnar nerve. These findings are compatible with functional changes without a clinically manifest neuropathy and they are suggestive of a compression damage such as carpal tunnel syndrome: the possible pathogenic mechanism of these damages are discussed. It's necessary to emphasize the importance of further studies in order to estimate the type and entity of the exposure to vibrations to show a cause-effect relationship.