Scientists develop new ruthenium-based caged compounds

Thu, 04 Mar 2010 00:00:00 GMT

Two new ruthenium-based caged compounds have been championed for their ability to aid a number of simple scientific research techniques.

Caged compounds typically tend to be activated by breaking their photolabile bond with the chemical group ('cage') with light, providing a useful approach for studying molecular mechanisms.

However, RuBi-Glutamate and RuBi-4AP both possess significant advantages over their contemporaries and have been included in the Tocris Bioscience and Columbia University license agreement.

The former, which is excited by visible wavelengths, has high quantum efficiency and can be used at low concentrations, thus reducing the levels of GABAergic transmission displayed by other caged glutamate compounds.

In addition, it requires only a one or two-photon excitation in order to release glutamate - which is the predominant neurotransmitter of the human brain - at rapid speeds of tens of nanoseconds.

Meanwhile, the latter, which is also excited by visible wavelengths, boasts two-photon uncaging abilities and releases a voltage-dependent potassium channel blocker known as 4-AP.

The channels to which this by-product relates are in control of synaptic release and are essential to the smooth operation of the nervous system.

"Compared to currently available ultraviolet light-sensitive caged compounds, RuBi-Glutamate and RuBi-4AP can all be uncaged using longer wavelengths of light," said Rafael Yuste, a Professor in the Department of Biological Sciences at Columbia University.

"[The result is] less scattering and allowing the light source to penetrate deeper into living tissue. This could be key for their future use in vivo," added Professor Yuste, who is also an Investigator at the Howard Hughes Medical Institute and a co-inventor of the technology.

Ruthenium compounds tend to be similar to those of another pgm, osmium, and exhibit at least eight oxidation states.

Source:

Tocris Bioscience Extends Novel Range of Fast, Light-Sensitive Caged Compounds Developed by Columbia University (01/03/10)

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Exploration Roundup February 2010

Wed, 24 Feb 2010 00:00:00 GMT

Positive bankable feasibility study findings (03/02/10)

The findings of a Bankable Feasibility Study (BFS) for the Garatau platinum project in South Africa's Bushveld Complex have been declared "extremely positive" by Nkwe Platinum managing director Maredi Mphahlele. On the back of the BFS, the measured resources estimate has been increased by around 300 per cent from 4.5 million ounces 3PGE+Au to 14.2 million ounces. Meanwhile, predicted inferred resources amount to 9.1 million ounces. The encouraging results mean the project time-line will be reassessed, Mr Mphahlele confirmed. "Based on the very positive BFS findings Nkwe will fast-track finalisation of the Joint Venture with Xstrata and completion of the optimised BFS (scheduled for April 2010) to enable an accelerated project development timetable," he commented. It is thought that the mine will eventually produce between 240,000 and 400,000 tonnes per month, with an initial mine life of more than 40 years. Construction is expected to start in 2011, with ramp up to steady state production by 2016.

North American Palladium files for $300 mln mixed shelf (26/01/10)

North American Palladium (NAP) plans to sell debt securities, common shares, warrants and units up to the value of $300 million over the next 25 months, Reuters reports. The money will be used to fund exploration and development at the company's Lac des Iles and Sleeping Giant mines in Canada, as well as at its Dormex and Discovery properties. A filing made with the US Securities and Exchange Commission by NAP suggests the feasibility of developing additional sites may also be investigated.

NAP's exploration program delivers excellent results at Offset and Cowboy; company doubles exploration budget for 2010 (25/01/10)

The news comes soon after the company announced the doubling of its 2010 exploration budget for the Lac des Iles mine to $15 million. According to William J Biggar, NAP's president and chief executive officer, exploration efforts at Lac des Iles are producing "positive results". Mr Bigger said the company will further its quest to improve its resources and reserves position, while also concentrating on efforts to maximise production at the Roby Underground mine. Additionally, assessment and development at the Offset zone will continue, with a $16 million ramp into the area set to increase the opportunity for drilling as well as allow improved access for the installation of a shaft to surface. The company's exploration results show holes 404, 414, 415 and 417 contain some of the higher grade intersections in the Offset zone. Meanwhile, drilling in the northern part of the Offset zone has also been productive, with holes 902, 903 and 904 intersecting multiple wide, high grade zones. Over in the Cowboy zone, hole 410 produced the best results, with 18 metres grading 8.91 g/t palladium, including six metres grading 10.64 g/t palladium.

Anooraq announces Ivanhoe Nickel & Platinum dispute settled & extended joint venture agreed between parties (23/02/10)

Finally, Anooraq Resources and Ivanhoe Nickel & Platinum (Ivanplats) have resolved a dispute concerning the Rietfontein property in South Africa's Bushveld Complex. The wrangle centred on a 2001 agreement which gave Ivanplats the chance to attain a 50 per cent stake in the Rietfontein property by funding exploration work which fell within the approved technical programmes remit. However, a new agreement has been reached which has seen both companies dismiss their respective grievances. "We are pleased with the resolution of this dispute. The revised agreement maintains our interest in the Rietfontein mineral property but extends the possibility for further development with the addition of [Ivanhoe's neighbouring mineral property] Turfspruit," Anooraq CEO Philip Kotze confirmed. "We look forward to working with Ivanplats in taking this project to the feasibility study level."

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Platinum today: News/Miscellaneous

Scientists develop new ruthenium-based caged compounds

Exploration Roundup February 2010