Quantum Cascade Laser Based Infrared Spectroscopy: A New Paradigm for Protein Secondary Structure Measurement.

Mid-infrared spectroscopy is one of the major analytical techniques employed for measurements of protein structure in solution. Traditional Fourier Transform-Infrared (FT-IR) measurement is limited by its blackbody light source that is inherently spatially incoherent and has low optical power output. This limitation is pronounced when working with proteins in aqueous solutions. Strong absorbance of water in protein amide I region 1600-1700 cm-1 restricts light path length to <10 µm and imposes significant experimental challenges in sample and flow cell handling. Emerging laser spectroscopic techniques use high-power coherent laser as light source that overcomes the limitation in FT-IR measurement. In this study, we employed an innovative infrared spectrometer that uses quantum cascade laser (QCL) as light source. Continuous infrared radiation from this laser source can be swiftly swept within the amide I region (1600-1700 cm-1) and amide II region (1500-1600 cm-1), which makes this technique ideal for protein secondary structure study. Protein solutions as low as 0.5 mg/mL were measured rapidly without any sample preparation. Infrared spectra of model proteins were thus collected, and a chemometric model based on partial least squares regression was developed to quantify α-helix and ß-strand motifs in protein secondary structure. The model was applied to measurement of the native secondary structure of commercial therapeutic proteins and bovine serum albumin (BSA) and in thermal degradation studies.

Pressure ulcer prevention: making a difference across a health authority?

Pressure ulcers (PUs), their cause and prevention have been discussed in the literature for many decades. Their prevention and management has been the core of a tissue viability nurse's daily clinical and strategic workload. The important point to acknowledge is that not all PUs can be prevented but it is believed most of them can and all preventative measures must be implemented and evaluated. Initial efforts focused on establishing a baseline of incidence and prevalence. More recently, the Department of Health has proposed that PUs could be eliminated in 95% of all NHS patients and incentivised the measurement of PUs and other harms by use of the NHS Safety Thermometer through the introduction of a new initiative. A research company was commissioned to explore which communications interventions would be effective in helping health professionals to prevent and treat PUs. A campaign was subsequently set in motion to educate and inform clinical staff on the cause and prevention of PUs.