Stabilising the Blue Phases

We present an investigation of the phase diagram of cholesteric liquid crystals within the framework of Landau - de Gennes theory. The free energy is modified to incorporate all three Frank elastic constants and to allow for a temperature dependent pitch in the cholesteric phase. It is found that the region of stability of the cubic blue phases depends significantly on the value of the elastic constants, being reduced when the bend elastic constant is larger than splay and when twist is smaller than the other two. Most dramatically we find a large increase in the region of stability of blue phase I, and a qualitative change in the phase diagram, in a system where the cholesteric phase displays helix inversion.Comment: 15 pages, 6 figure

Surgical treatment of lumbar spinal stenosis with microdecompression and interspinous distraction device insertion. A case series

<p>Abstract</p> <p>Background</p> <p>Interspinous distraction devices (IPDD) are indicated as stand-alone devices for the treatment of spinal stenosis. The purpose of this study is to evaluate the results of patients undergoing surgery for spinal stenosis with a combination of unilateral microdecompression and interspinous distraction device insertion.</p> <p>Methods</p> <p>This is a prospective clinical and radiological study of minimum 2 years follow-up. Twenty-two patients (average age 64.5 years) with low-back pain and unilateral sciatica underwent decompressive surgery for lumbar spinal stenosis. Visual Analogue Scale, Oswestry Disability Index and walking capacity plus radiologic measurements of posterior disc height of the involved level and lumbar lordosis Cobb angle were documented both preoperatively and postoperatively. One-sided posterior subarticular and foraminal decompression was conducted followed by dynamic stabilization of the diseased level with an IPDD (X-STOP).</p> <p>Results</p> <p>The average follow-up time was 27.4 months. Visual Analogue Scale and Oswestry Disability Index improved statistically significantly (p < 0.001) in the last follow-up exam. Also, the walking distance increased in all patients but two. Posterior intervertebral disc height of the diseased level widened average 1.8 mm in the postoperative radiograph compared to the preoperative. No major complication, including implant failure or spinous process breakage, has been observed.</p> <p>Conclusions</p> <p>The described surgical technique using unilateral microdecompression and IPDD insertion is a clinically effective and radiologically viable treatment method for symptoms of spinal stenosis resistant to non-operative treatment.</p

Identification of hemoglobin variants by top-down mass spectrometry using selected diagnostic product ions

Hemoglobin disorder diagnosis is a complex procedure combining several analytical steps. Due to the lack of specificity of the currently used protein analysis methods, the identification of uncommon hemoglobin variants (proteoforms) can become a hard task to accomplish. The aim of this work was to develop a mass spectrometry-based approach to quickly identify mutated protein sequences within globin chain variants. To reach this goal, a top-down electron transfer dissociation mass spectrometry method was developed for hemoglobin β chain analysis. A diagnostic product ion list was established with a color code strategy allowing to quickly and specifically localize a mutation in the hemoglobin β chain sequence. The method was applied to the analysis of rare hemoglobin β chain variants and an Aγ-β fusion protein. The results showed that the developed data analysis process allows fast and reliable interpretation of top-down electron transfer dissociation mass spectra by nonexpert users in the clinical area

Identification of hemoglobin variants by top-down mass spectrometry using selected diagnostic product ions

Hemoglobin disorder diagnosis is a complex procedure combining several analytical steps. Due to the lack of specificity of the currently used protein analysis methods, the identification of uncommon hemoglobin variants (proteoforms) can become a hard task to accomplish. The aim of this work was to develop a mass spectrometry-based approach to quickly identify mutated protein sequences within globin chain variants. To reach this goal, a top-down electron transfer dissociation mass spectrometry method was developed for hemoglobin β chain analysis. A diagnostic product ion list was established with a color code strategy allowing to quickly and specifically localize a mutation in the hemoglobin β chain sequence. The method was applied to the analysis of rare hemoglobin β chain variants and an (A)γ-β fusion protein. The results showed that the developed data analysis process allows fast and reliable interpretation of top-down electron transfer dissociation mass spectra by nonexpert users in the clinical area

Identification of hemoglobin variants by top-down mass spectrometry using selected diagnostic product ions

Hemoglobin disorder diagnosis is a complex procedure combining several analytical steps. Due to the lack of specificity of the currently used protein analysis methods, the identification of uncommon hemoglobin variants (proteoforms) can become a hard task to accomplish. The aim of this work was to develop a mass spectrometry-based approach to quickly identify mutated protein sequences within globin chain variants. To reach this goal, a top-down electron transfer dissociation mass spectrometry method was developed for hemoglobin β chain analysis. A diagnostic product ion list was established with a color code strategy allowing to quickly and specifically localize a mutation in the hemoglobin β chain sequence. The method was applied to the analysis of rare hemoglobin β chain variants and an (A)γ-β fusion protein. The results showed that the developed data analysis process allows fast and reliable interpretation of top-down electron transfer dissociation mass spectra by nonexpert users in the clinical area