November's Paper of the Month

Due to its unique properties Graphene (an allotrope of carbon) has incredible potential for application in many different fields. 

Graphene has been a hot topic in both fundamental science and practical applications since it was first isolated in 2004. It is the most conductive material known and has many other attractive properties such as flexibility, transparency and impermeability. This makes it suitable for application in wide-ranging areas such as sanitation, biomedical science and electronics. 

The incredible features and applications of this material can be generated by adding layers of graphene on top of a single graphene layer. The interlayer shear modes in these few-layer graphene are very important for understanding their exceptional properties. However, these modes are in very low frequency range with very weak intensities which greatly hinders exploration.

This month’s Paper of the Month comes from Nanyang Technological University, in Singapore. Cong, currently a professor of Fudan University, and Ting demonstrated methods of improving intensities of the shear modes of graphene layers which would in turn allow better probing of few-layer graphene itself and exploration of its application. 

Cong and Ting discovered a way to enhance such interlayer shear modes through folding the bernal-stacked graphene layers with certain twisting angles. They used Linkam’s electrical probe stage, the HFS600E-PB4, which has a temperature range of -196°C to 600°C in their temperature dependant in-situ Raman spectroscopy experiments. 

When asked to comment on the motivation behind their work, and the purpose of the Linkam stage, Dr Cong said: 

“Investigations of shear modes in few-layer graphene are greatly hindered by the truth that shear modes of graphene layers are extremely weak and almost fully blocked by a Rayleigh rejecter in Raman measurements. 

We found that the shear modes could be dramatically enhanced by properly folding graphene layers. Such strong signals offer the feasibility of performing systematically in-situ temperature Raman scattering measurements with the help of a Linkam stage. The vibrational symmetry, anharmonicity and electron-phonon coupling of the shear modes of graphene layers are uncovered through studies of temperature-dependent Raman spectroscopy. 

The Linkam stage which is compatible with our confocal low-frequency Raman system, helps us to realize the temperature-dependent Raman measurement with liquid nitrogen”.

Their research will provide a better insight into the mechanical and electrical properties of graphene. 

By Tabassum Mujtaba

Cong, C. & Ting, Y. Enhanced ultra-low-frequency interlayer shear modes in folded graphene layers. Nat Commun. 5:4709 | DOI: 10.1038/ncomms5709 (2014). 

Reaching New Peaks

Denver, Colorado is the location for this year’s AAPS annual meeting

The Colorado city of Denver, nick-named the Mile-High City because its elevation is exactly one mile above sea level, is a gateway to the snow-capped Rocky Mountains. This year it plays host to the American Association of Pharmaceutical Scientists (AAPS) 2016 annual meeting. 

This week, from 13th to 16th November, the Linkam sales team will be heading to the Colorado Convention Centre for this year’s meeting. We will be bringing our humidity generator RH95, the thermal stage THMS600 and the freeze drying cryo-stage FDCS196.

We are also excited to be announcing the launch of two new Linkam stages – a brand new vial based freeze drying system and a dual pan optical DSC. 

Many of our products are perfect for sample characterisation in the pharmaceutical market. They can be used for a variety of applications including quality assurance, developing freeze drying protocols, dissolution studies and many more.

Come and see us on booth 1470 to discuss how our stages can enhance your sample characterisation needs.

We look forward to seeing you there. 

September's Paper of the Month

From the mating dance of the peacock spider to brood parasitism in the common cuckoo, behavioural ecology is a fascinating and complex science. It is defined as the study of the evolutionary behaviour of animals due to ecological selection pressures, and even the smallest of organisms such as bacteria can effectively emulate eukaryotic social behaviours. 

Streptomycetes are one such genus which can form multi-cellular colonies with distinct multi-nucleated hyphae structures. These hyphae have distinct compartments separated through infrequent cross-walls. The group is also significant due to their medicinal purpose; they produce over half of the world’s antibacterial and antiparasitic drugs and are commonly known for their forest like smell caused by the organic compound Geosmin. 

The group harbour perplexing traits and behaviours. When mechanically macerated, the hyphae surprisingly do not ‘bleed’ to death suggesting the end is plugged and compartmentalised. Furthermore, growing hyphal tips can form up to 100 septa and in such multi-nucleated species, which lack DNA damage control proteins, we are left wondering how DNA can be protected from intense intra-cellular movement. 

September’s Paper of the Month is a collaboration between the laboratory of Professor Gilles Van Wezel and the Koster laboratory and their work using the CMS196M to answer the questions surrounding the complex behaviour of Streptomyces albus.

Underground at St Pancras

When you next take a train from St Pancras have a think about what might be going on beneath your feet.

Just across the road from the station, and 28 metres below the pavement, world leaders in their field are working with some of the highest resolution microscopes on the market to investigate the causes of cancer and other diseases. 

The recently opened Frances Crick Institute brings together scientists from all over the world under one roof and is a partnership between Cancer Research UK, Imperial College, King's College, the Medical Research Council, University College London and the Wellcome Trust. 

I was privileged to be invited to visit recently and I would like to thank the Head of Electron Microscopy, Lucy Collinson, and her colleague, Marie Charlotte, for an extremely interesting tour of the labs.