3-D Vision Reaches Molecular Spectroscopy
In an age where technological advances are occurring as a result of research at the molecular level, spectroscopic instruments for molecular structure determination are more crucial than ever. To the list of existing instrumentation, the ChiralRAMAN ROA Spectrometer developed by a research team at BioTools, Inc., Wauconda, Ill., can now be added. Joining the key features of two types of spectrometers, a laser Raman and a circular dichroism, this tool can be used to obtain the Raman optical activity (ROA) spectra from any chiral molecular sample, allowing users to “see” molecules with “3-D vision.”
ROA combines the sensitivity of Raman scattering to molecular structure with the stereo sensitivity of optical activity to absolute molecular structure, measuring the difference in Raman scattering intensity for left versus right circularly polarized radiation. While ordinary Raman scattering is the same for mirror image pairs of molecules, the ROA spectra of mirror image pairs of molecules are identical in form but opposite in sign for all the bands in the spectrum.
Yet, ROA studies have been limited because the ROA signal is about 1,000 times smaller than conventional Raman intensities. The ChiralRAMAN ROA Spectrometer removes these limitations by integrating special combinations of rotating and interchanging optical elements for nearly complete artifact elimination.
>>More info: www.btools.com
| Breaching the THz Frontier
The terahertz (THz) gap is the last unexplored region of the electromagnetic spectrum. To access this region, The TPI-spectra1000 was developed by Phil Taday at TeraView Ltd, Cambridge, UK, and a team of scientists at Bruker Optics Inc., Billerica, Mass., as an easy-to-use THz far-infrared (far-IR) pulsed transmission spectrometer. It extends researchers’ ability to measure molecular vibrations in the far-IR region of the electromagnetic spectrum. Such an exploration would enable spectroscopists to study DNA, RNA, biopolymer tertiary conformation, protein folding, molecular docking, and solvation mechanisms.
This instrument uses a well-known technique in the generation and detection of THz light with a Ti:sapphire laser. It provides absorption and refractive index spectral information between 1.3 and 133.3 cm-1 , with a 2000:1 signal-to-noise ratio. Operating without the need for bolometric or cryogenic detectors, the device can be used by research spectroscopists as they would a traditional FT-IR instrument, with the additional benefits of the wide THz spectral range, fast data capture, and the integral ability to perform pump-probe experiments.
The TPIspectra1000 also has a high sensitivity for the detection of crystalline lattice vibrations, which is useful for pharmaceutical polymorphic screening.
>>More info: www.teraview.com
| Imaging Exploits Remote Sensing
Hyperspectral imaging applications that require high spectral/spatial resolution, such as in the detection of cancer cells at sub-micron levels, are enabled by the Hyperspec VS. Within a small footprint, this imaging spectrograph developed by Tom Mikes and Jay Julian at Headwall Photonics, Inc., Fitchburg, Mass., provides a non-contact method for obtaining critical spectral (chemical) data of a scene or sample at high rates of speed for remote sensing. These observations can be made sitting atop a moving conveyor belt, from the cockpit of a search and rescue airplane, or from a satellite orbiting the earth.
The Hyperspec VS generates precise spectral imaging within a spatial framework, with high resolution (~1.5 nm) and minimal image distortion. The high spatial/spectral resolution is achieved by the use of tall slit sizes, which allow for a significant number of pixels to be used. The reduction in image distortion, on the other hand, is due to the aberration-correction of the image through proprietary algorithms and image processing, which minimize any distortions attributable to the "smile" and "keystone" effects.
Headwall's aberration-corrected imaging spectrograph is the only spectral engine that offers the degree of optical precision and image resolution necessary to use hyperspectral imaging to exploit the potential of remote sensing. Additionally, customization of holographic grating components allows this product to be deployed and used in various spectral ranges, including UV and vis-NIR.
>>More info: www.headwallphotonics.com
| Giving Dimension to Molecular Structures
The fervor of activity within drug discovery and development and proteomic research has spawned the creation of a host of advanced methodologies and instrumentation to better serve the need of researchers in resolving protein structures. The information gleaned from these trials is the basis behind the creation of new and more effective, therapeutic drugs, with minimal side effects.
Damian Kucharczyk, director of research & development at Oxford Diffraction, Wroclaw, Poland, and colleagues have created the XCalibur PX Ultra, an x-ray diffractometer for protein and molecular studies. Rather than using rotating anode generators, this tool enlists a proprietary conventional sealed-tube technology, dubbed EnhanceUltra, as its x-ray source. The x-ray flux with this approach is comparable to that of a standard rotating anode generator, but comes with a substantial decrease in cost of ownership, that is nearly 10 times less. Through its inclusion of a 165-mm aperture CCD detector, rather than an image plate, the XCalibur is able to provide x-ray crystallographers with data acquisition rates that are more than ten times faster. Fine slicing for better data quality is also featured along with minimal maintenance, allowing for virtually no downtime.
>>More info: www.oxforddiffraction.com
| | Hybridization Unites Spectrometers
Bottom-up or top-down proteomic analyses, metabolomics, and all other applications where high resolution and accurate mass determinations are required stand to be impacted by the Finnigan LTQ FT created by Bremen, Germany-, and San Jose, Calif.-based research groups at Thermo Electron Corp. This hybrid ion trap Fourier transform (FT) ion cyclotron resonance (ICR) mass spectrometer (MS) combines the advantages of both the linear ion trap and FTMS, enhancing sensitivity, resolution, and mass measurements. After ion formation with any of the atmospheric pressure ionization modes like electrospray ionization, the linear ion trap stores, detects or isolates specific ions for subsequent full scan, MS/MS, and MSn experiments on the liquid chromatography (LC) time scale.
When ions are sent into the Finnigan LTQ FT’s ICR cell, proteomic researchers are able to obtain high resolution (less than 500,000 FWHM) and accurate mass measurements (better than 2 ppm RMS error with external calibration). The mass determinations are due to its Automatic Gain Control, which limits the number of ions in the ICR cell. Moreover, the resolution and mass measurements are available at a fast acquisition rate of 100,000 at 1 scan/sec when operating the ion trap in parallel. With these capabilities, the LTQ FT makes online LC-MS and LC-MS/MS a routine method in FTMS.
>>More info: www.thermo.com
| Microfluidic Control Yields Nano-flow Rates
The majority of the world’s current drugs act by blocking the effects of proteins that are part of a disease pathway. To identify which proteins play a role in diseases, researchers are increasingly turning to the power of liquid chromatography/mass spectrometry (LC/MS). This technique’s detection sensitivity is increased by the NanoLC-1D Proteomics System , which runs at low flow rates, 20 nL/min, where the MS is most sensitive. Designed for highly sensitive nano-electrospray LC/MS proteomic research, this product uses direct pumping, making the system robust in operation and simplifying the setup and operation of LC/MS/MS experiments.
The generation of precise LC gradients at nL/min flow rates without flow splitting is due to a microfluidic flow control (MFC) incorporated in the system developed by researchers at Eksigent Technologies, Livermore, Calif. Flow meters in each mobile phase continuously monitor the flow rates and feed a proportional signal back to a microprocessor, which sends out a voltage signal to the controller at the pressure source for each mobile phase. This signal is proportional to the pressure required in each mobile phase to achieve the desired flow rate. The pressure is regulated by the MFC controller, generating the required flow rate.
In addition to the precise control of gradients at nanoscale flow rates, MFC’s rapid pressure control also allows the flow rate to be changed dynamically during a gradient run.
>>More info: www.eksigent.com
| Streamlining Superconductor Analysis
Researchers at SuperPower, Inc., Schenectady, N.Y., XOS (X-Ray Optical Systems) Inc., East Greenbush, N.Y., and the New York State Energy Research and Development Authority (NYSERDA), Albany, have come together to create the EXCELL: Tabletop X-Ray Diffraction System that Enables X-rays to Continuously Measure End-to-End Long Length Samples. The EXCELL tabletop diffraction system directly measures texture on long-lengths of moving high-temperature, superconducting tape during and after processing, allowing for stability and reliability.
With a large capture angle and high-transmission efficiency, it provides a quasi-parallel x-ray beam from a compact, air-cooled, low-power (50 W) x-ray source with intensity comparable to water-cooled, high-power (500 to 1,000 W) laboratory sources. Trials have proven the system’s ability to collect and automatically analyze 50 pole figures in less than an hour, whereas manual analysis would require 12 hr or more for the same volume of data.
The system is already being deployed in Albany to measure the texture of five miles of superconducting cable that has been positioned under the city as a means to replace the ageing electrical grids.
>>More info: www.igc.com/superpower/index.htm
| Sniffing Out Terrorists’ Tools
Plastic explosives pose an ever-present terrorist threat because of their easy availability and ability to be shaped for concealment. Despite the urgency of the war on terrorism, human injury and loss of life continue due to the lack of technological advancements in countering terrorist bombings. In addition, unexploded landmines remain a gruesome fact of life, endangering civilians after the fighting is over.
Plastic explosives are hard to detect because they have low vapor pressures. However, even well-concealed explosives release small amounts of vapor (in parts-per-
trillion (ppt) concentrations) that escape their containment to the surrounding air. SniffEx , a compact, low-cost explosive vapor sensor, samples the air around people and packages, capturing and identifying explosive molecules in seconds with sub-ppt sensitivity.
Created by a research team at Oak Ridge National Laboratory, Tenn., and Eric Houser, Stan Stepnowski, and Andy McGill at the Naval Research Laboratory, Washington, D.C., molecules adsorb on this product's microelectromechanical systems (MEMS) sensor for identification. The sensor is chemically treated so only explosive molecules can chemically bind to it. The bound molecules then impart a surface stress to the sensor, and a measurement of the stress provides a signature that identifies the bound molecules. The sensor regenerates itself after each use in a few seconds.
>>More info: www.ornl.gov
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