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Synthesis of optical spectra

3 April 2017:

A new publication from CNBP researchers (lead author Dr Ivan Maksymov pictured)  demonstrates a new scheme for synthesis of optical spectra from nonlinear ultrasound harmonics using a hybrid liquid-state and nanoplasmonic device compatible with fibre-optic technology.

The work has just been reported in the journal ‘Optics Express’ and is accessible online.

Journal: Optics Express.

Title: Synthesis of discrete phase-coherent optical spectra from nonlinear ultrasound.

Authors: Ivan S. Maksymov and Andrew D. Greentree.

Abstract: Nonlinear acoustic interactions in liquids are effectively stronger than nonlinear optical interactions in solids. Thus, harnessing these interactions will offer new possibilities in the design of ultra-compact nonlinear photonic devices. We theoretically demonstrate a new scheme for synthesis of optical spectra from nonlinear ultrasound harmonics using a hybrid liquid-state and nanoplasmonic device compatible with fibre-optic technology. The synthesised spectra consist of a set of equally spaced optical Brillouin light scattering modes having a well-defined phase relationship between each other. We suggest that these spectra may be employed as optical frequency combs whose spectral composition may be tuned by controlling the nonlinear acoustic interactions.

New sensing methods for embryos

2 April 2017:

A/Prof Jeremy Thompson, CNBP Chief Investigator, has given an invited talk at  the 7th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2017) in Kuala Lumpur, Malaysia, on the 2nd April 2017.

The Congress is the largest clinical reproductive medicine meeting in the Asia-Pacific region with A/Prof Thompson’s talk titled, “New sensing methods for embryos.”

 

Centre CI at Gordon Glycobiology conference

25 March 2017:

CNBP Chief Investigator Professor Nicki Packer was an invited chair of a session and leader of the Power Hour (gender equality workshop)  at the Gordon Glycobiology conference at Ventura, California 19-24 March, 2017.

As session Chair, Prof Packer led discussion on advances in omics, integrated omics, bioinformatics for glycobiology and the impact of altered glycosylation for human disorders.

The Power Hour was an informal session designed to help address the challenges women face in science and to support the professional growth of women by providing an open forum for discussion and mentoring.

Further conference information is accessible online.

 

Microscopy meet ‘big data’

22 March 2017:

Cell Systems has published an invited preview article authored by CNBP Research Fellow Dr Antony Orth along with collaborators from Harvard University and Massachussetts General Hospital.

The commentary article discusses how data-driven methods are poised to shake-up how we approach bio-microscopy. Microscopy-based assays can be made more informative and more predictive when paired with a library of reference images. The preview puts new results in this field into context and suggests further avenues of research.

The article is accessible online although a subscription is required.

 

Bubbles can detect sound, with light

13 March 2017:

CNBP scientists Dr Ivan Maksymov and Prof Andy Greentree at RMIT University have shown bubbles can detect sound with light in their latest publication in the area of photo-acoustics.

“Bubbles can be a boon for detecting the kind of ultrasound used in medicine as air is less dense than water” explains Dr Ivan Maksymov, “so ultrasound can squeeze a bubble more than the water surrounding it”.

To detect the change in size, Ivan showed that the bubbles could change the amount of light that passed through a gold membrane with nanosized holes in it. “It’s incredible work, I’m really excited by how Ivan has brought together these different kinds of Physics to create something quite new”, said the study’s co-author Prof Andy Greentree.

To detect the effects of sound on the bubble, on light, Ivan had to develop new computational models. The team say that their work may be useful in the development of an optical hydrophone for detecting ultrasound inside the body. “It will give us a new and potentially more sensitive way to ‘see’ with sound” says Ivan.

The work was published in the journal Physical Review A on 13th March 2017 and was funded by the Australian Research Council Centre of Excellence for Nanoscale BioPhotonics.

Breaking apart sugars

9 March 2017:

CNBP scientists Chris Ashwood and Prof Nicki Packer at Macquarie University have shown alternative ways to break apart sugars, improving their characterisation in their latest publication in the area of mass spectrometry (Enhancing structural characterisation of glucuronidated O-linked glycans using negative mode ion trap higher energy collision-induced dissociation mass spectrometry).

The work was published online in the journal Rapid Communications in Mass Spectrometry on 9th March 2017 and was funded by the Australian Research Council Centre of Excellence for Nanoscale BioPhotonics.

Investigating cell metabolism

Aziz Rehman1 March 2017:

A new publication from CNBP researchers (lead author Aziz Ul Rehman pictured) reports on the application of hyperspectral imaging in combination with fluorescence spectroscopy and chemical quenching to provide a new methodology to investigate cell metabolism.

The work has just been reported in the journal ‘Biomedical Optics Express’ and is accessible online.

Journal: Biomedical Optics Express.

Title: Fluorescence quenching of free and bound NADH in HeLa cells determined by hyperspectral imaging and unmixing of cell autofluorescence.

Authors: Aziz Ul Rehman, Ayad G. Anwer, Martin E. Gosnell, Saabah B. Mahbub, Guozhen Liu, and Ewa M. Goldys.

Abstract: Carbonyl cyanide-p-trifluoro methoxyphenylhydrazone (FCCP) is a well-known mitochondrial uncoupling agent. We examined FCCP-induced fluorescence quenching of reduced nicotinamide adenine dinucleotide / nicotinamide adenine dinucleotide phosphate (NAD(P)H) in solution and in cultured HeLa cells in a wide range of FCCP concentrations from 50 to 1000µM. A non-invasive label-free method of hyperspectral imaging of cell autofluorescence combined with unsupervised unmixing was used to separately isolate the emissions of free and bound NAD(P)H from cell autofluorescence. Hyperspectral image analysis of FCCP-treated HeLa cells confirms that this agent selectively quenches fluorescence of free and bound NAD(P)H in a broad range of concentrations. This is confirmed by the measurements of average NAD/NADH and NADP/NADPH content in cells. FCCP quenching of free NAD(P)H in cells and in solution is found to be similar, but quenching of bound NAD(P)H in cells is attenuated compared to solution quenching possibly due to a contribution from the metabolic and/or antioxidant response in cells. Chemical quenching of NAD(P)H fluorescence by FCCP validates the results of unsupervised unmixing of cell autofluorescence.

Automation in the IVF laboratory

23 February 2017:

CNBP Chief Investigator A/Prof Jeremy Thompson has delivered a talk to the “Best of ASRM-ESHRE” forum, in Paris, February 23, 2017.

The forum, a joint initiative of the American Society for Reproductive Medicine (ASRM) and the European Society of Human Reproduction and Embryology (ESHRE) brings together 1200 delegates focused in the science of reproductive medicine, with updates on the latest concepts and developments presented in a framework of lectures, debates and back-to-back sessions.

A/Prof Thompson’s well received talk was titled, “Automation in the IVF Laboratory – what works and what hasn’t.”

Dictionary-enhanced imaging cytometry

22 February 2017:

A new paper by CNBP researcher Tony Orth (lead author pictured) describes how to use large image sets to perform cell classification and imaging performance. The work combines years of hardware development on a high throughput microlens microscope together with large scale image processing.

The authors on the paper found that they could get a computer to accurately identify white blood cells types purely from a reference set of images (or dictionary), without resorting to time-consuming manual classification by trained staff.

Moreover, the authors demonstrated that because white blood cells come in a limited number of shapes and sizes, even a very poor quality noisy image of a white blood cell can be effectively enhanced by looking for similar images in the dictionary set.

This has potential applications for low-light level imaging. Working with a small amount of light is detrimental in terms of image quality but gentle on cells. The author’s dictionary-based method provides a way to partially recover image quality for dose-limited imaging.

The paper is accessible online.

Dictionary-enhanced imaging cytometry. Antony Orth, Diane Schaak and Ethan Schonbrun. Scientific Reports 7, Article number: 43148 (2017).