Discrimination of thermophilic and mesophilic proteins

<p>Abstract</p> <p>Background</p> <p> There is a considerable literature on the source of the thermostability of proteins from thermophilic organisms. Understanding the mechanisms for this thermostability would provide insights into proteins generally and permit the design of synthetic hyperstable biocatalysts.</p> <p>Results</p> <p> We have systematically tested a large number of sequence and structure derived quantities for their ability to discriminate thermostable proteins from their non-thermostable orthologs using sets of mesophile-thermophile ortholog pairs. Most of the quantities tested correspond to properties previously reported to be associated with thermostability. Many of the structure related properties were derived from the Delaunay tessellation of protein structures.</p> <p>Conclusions</p> <p> Carefully selected sequence based indices discriminate better than purely structure based indices. Combined sequence and structure based indices improve performance somewhat further. Based on our analysis, the strongest contributors to thermostability are an increase in ion pairs on the protein surface and a more strongly hydrophobic interior.</p

Mechanics of musculoskeletal repair devices

This paper applies the mechanics of engineering science and materials to the understanding of clinical devices used in Orthopaedics and Trauma. The rigidity of devices is described to be a function of material stiffness and its geometry relative to the loading axes. Structures are more rigid under loads that are applied along their long axes and are more flexible under bending and torsion, which increases with length. This may be applied to an individual plate, screw or bone and to the entire construct. Increasing the thickness of a plate greatly increases rigidity as a third power relationship exists between these variables. Similarly, increasing the diameter of a rod increases its rigidity by a fourth power relationship. A hollow cylindrical cross-section, as found in long bones, provides the most effective rigidity to weight ratio when complex stresses are applied. This paper provides examples to reinforce basic structural mechanics applied to medical devices

Has the publics knowledge of anatomy been hamstrung? A questionnaire-based exploration of basic anatomical awareness within the general population

Despite a recent resurgence in public interest for anatomical sciences,1 little research exists to determine the extent of their knowledge. We aimed to assess this through a questionnaire-based localisation of anatomical structures. Our findings suggest a significant gender discrepancy, as well as the presence of prevalent anatomical misconceptions which, to our best knowledge, have not been documented in the literature. These results have implications for the content and targeting of future public and clinical teaching

High Spatial Resolution Observations of Two Young Protostars in the R Corona Australis Region

We present multi-wavelength, high spatial resolution imaging of the IRS 7 region in the R Corona Australis molecular cloud. Our observations include 1.1 mm continuum and HCO^+ J = $3 \to 2$ images from the SMA, ^{12}CO J = $3 \to 2$ outflow maps from the DesertStar heterodyne array receiver on the HHT, 450 $\mu$m and 850 $\mu$m continuum images from SCUBA, and archival Spitzer IRAC and MIPS 24 \micron images. The accurate astrometry of the IRAC images allow us to identify IRS 7 with the cm source VLA 10W (IRS 7A) and the X-ray source X_W. The SMA 1.1 mm image reveals two compact continuum sources which are also distinguishable at 450 $\mu$m. SMA 1 coincides with X-ray source CXOU J190156.4-365728 and VLA cm source 10E (IRS 7B) and is seen in the IRAC and MIPS images. SMA 2 has no infrared counterpart but coincides with cm source VLA 9. Spectral energy distributions constructed from SMA, SCUBA and Spitzer data yield bolometric temperatures of 83 K for SMA 1 and $\leq$70 K for SMA 2. These temperatures along with the submillimeter to total luminosity ratios indicate that SMA 2 is a Class 0 protostar, while SMA 1 is a Class 0/Class I transitional object (L=$17\pm6$ \Lsun). The ^{12}CO J = $3 \to 2$ outflow map shows one major and possibly several smaller outflows centered on the IRS 7 region, with masses and energetics consistent with previous work. We identify the Class 0 source SMA 2/VLA 9 as the main driver of this outflow. The complex and clumpy spatial and velocity distribution of the HCO^+ J = $3 \to 2$ emission is not consistent with either bulk rotation, or any known molecular outflow activity.Comment: 31 pages, 8 figures, Accepted to Ap

Preprotachykinin A (PPTA) is expressed by a distinct population of excitatory neurons in the mouse superficial spinal dorsal horn including cells that respond to noxious and pruritic stimuli

The superficial dorsal horn, which is the main target for nociceptive and pruritoceptive primary afferents, contains a high density of excitatory interneurons. Our understanding of their roles in somatosensory processing has been restricted by the difficulty of distinguishing functional populations among these cells. We recently defined three non-overlapping populations among the excitatory neurons, based on the expression of neurotensin, neurokinin B (NKB) and gastrin-releasing peptide (GRP). Here we identify and characterise another population: neurons that express the tachykinin peptide substance P. We show with immunocytochemistry that its precursor protein (preprotachykinin A, PPTA) can be detected in ~14% of lamina I-II neurons, and these are concentrated in the outer part of lamina II. Over 80% of the PPTA-positive cells lack the transcription factor Pax2 (which determines an inhibitory phenotype), and these account for ~15% of the excitatory neurons in this region. They are different from the neurotensin, NKB or GRP neurons, although many of them contain somatostatin, which is widely expressed among superficial dorsal horn excitatory interneurons. We show that many of these cells respond to noxious thermal and mechanical stimuli, and to intradermal injection of pruritogens. Finally, we demonstrate that these cells can also be identified in a knock-in Cre mouse line (Tac1Cre), although our findings suggest that there is an additional population of neurons that transiently express PPTA. This population of substance P-expressing excitatory neurons is likely to play an important role in transmission of signals that are perceived as pain and itch

Reliability of posterolateral acromion process to examination table measurement to estimate shoulder protraction contracture

Study Design: Retrospective study. Objectives: To determine the reliability of measuring the perpendicular distance between the posterolateral acromion process and examination table to estimate passive shoulder protraction in student physical therapists. Background: Previous research has identified scapular dyskinesis to be associated with musculoskeletal shoulder pain, and commonly addressed by physical therapists. Tightness of the anterior shoulder muscles may be associated with scapular movement abnormality. Thus, reliable clinical measurements for anterior shoulder muscle length are imporrant for physical therapy care. Methods: After a 1 0-minute review session, two measurements of the distance between the posterior acromion process and examination table were obtained for both the dominant shoulders and nondominant shoulders in 12 nondisabled individuals (6 females, and 6 males age: 25.0 ± 2.4 years) by 12 student physical therapist examiners. A complete set of measurements from 10 subjects were available for analysis. Results: Mean (±standard deviation) measurements for the dominant (D) shoulder were 7.6 ± 2.0cm for Trial #1 and 7.4 ± 2.0 em for Trial #2, and 7.5 ± 2.lcm for Trial #l and 7.4 ± 2.3cm for Trial #2 for the nondominant (ND) shoulder. Tightness was determined in 85% and 86% for D and ND shoulders, respectively. The measurement demonstrated good intra-rater reliability (D: intradass correlation, formula 2,1; ICC2 _ 1 .751, 95% confidence interval; Cl: .628-.861; ND: .764, 95% CI: .645-.869) and moderate to good inter-rater reliability (D: ICC2 , 1 .651, 95% CI: .445-.876; ND: ICC2•1 = .733, 95% CI: .548-.911) considered as a continuous variable, \u3c}nd good percent agreement both within raters (94%) and between raters (90%) as a binomial variable. The coefficient of variation was acceptable (D: 25.8, ND: 28.4%). Standard error of measure was 0.99 em for D shoulders and 1.01 em for ND shoulders. Minimum detectable change outside the 95% confidence interval was 2.74 em forD shoulders and 2.80 em for ND shoulders. Conclusion: Measurement of the perpendicular distance between the posterolateral acromion process and examination table is a reliable method to estimate passive shoulder protraction in novice clinicians

'Abandoned by Medicine'? A qualitative study of women's experiences with lymphoedema secondary to cancer, and the implications for care

Background: Lymphoedema secondary to cancer is a relatively neglected and under-researched condition. Few studies report people's experiences of care and treatment provision when living with the condition. Current practice focuses on the physical treatment yet psychosocial needs often remain unmet. A previous study examining the patient perspective identified the theme of being ‘abandoned by medicine’. Perceived lack of support may result in a delayed adaptation and acceptance of this long-term condition and can significantly impact on psychological well-being. We explore this emerging theme alongside others in order to provide a guide to action for improvements for patient benefit. Aim: The central aim was to explore women's views of their care and treatment following a diagnosis with lymphoedema secondary to cancer. This forms part of a larger study aimed at assessing appropriate screening tools to measure psychosocial distress. Methods: A mixed-methods approach was used for the main study. Here we report the qualitative component, derived from in-depth semi-structured interviews conducted in the homes of the participants (n = 14) and focus group discussions (n = 15). In addition, qualitative comments from questionnaire data from a large-scale postal survey are included (n = 104). Findings: Participants identified considerable deficiencies in health care workers’ knowledge and awareness of lymphoedema, which subsequently impacted on the patients’ needs for information, support and understanding. Access to appropriate treatment was patchy and problems were identified with the process of obtaining compression garments, massage and other sources of help. Although lymphoedema is a long-term disfiguring condition, and much is known about how this impacts on patients’ emotional well-being, little attention was paid by health professionals to potential psychosocial consequences. In essence women had to become experts of their own condition and cope as best as they could. We provide recommendations to improve service delivery and address these unmet needs

Fibronectin and Cyclic Strain Improve Cardiac Progenitor Cell Regenerative Potential In Vitro.

Cardiac progenitor cells (CPCs) have rapidly advanced to clinical trials, yet little is known regarding their interaction with the microenvironment. Signaling cues present in the microenvironment change with development and disease. This work aims to assess the influence of two distinct signaling moieties on CPCs: cyclic biaxial strain and extracellular matrix. We evaluate four endpoints for improving CPC therapy: paracrine signaling, proliferation, connexin43 expression, and alignment. Vascular endothelial growth factor A (about 900 pg/mL) was secreted by CPCs cultured on fibronectin and collagen I. The application of mechanical strain increased vascular endothelial growth factor A secretion 2-4-fold for CPCs cultured on poly-L-lysine, laminin, or a naturally derived cardiac extracellular matrix. CPC proliferation was at least 25% higher on fibronectin than that on other matrices, especially for lower strain magnitudes. At 5% strain, connexin43 expression was highest on fibronectin. With increasing strain magnitude, connexin43 expression decreased by as much as 60% in CPCs cultured on collagen I and a naturally derived cardiac extracellular matrix. Cyclic mechanical strain induced the strongest CPC alignment when cultured on fibronectin or collagen I. This study demonstrates that culturing CPCs on fibronectin with 5% strain magnitude is optimal for their vascular endothelial growth factor A secretion, proliferation, connexin43 expression, and alignment

Preliminary Criticality Safety Evaluation for In Situ Grouting in the Subsurface Disposal Area

A preliminary criticality safety evaluation is presented for in situ grouting in the Subsurface Disposal Area (SDA) at the Idaho National Engineering Laboratory. The grouting materials evaluated are cement and paraffin. The evaluation determines physical and administrative controls necessary to preclude criticality and identifies additional information required for a final criticality safety evaluation. The evaluation shows that there are no criticality concerns with cementitious grout but a neutron poison such as boron would be required for the use of the paraffin matrix

Vapor Generation in a Nanoparticle Liquid Suspension Using a Focused, Continuous Laser

This letter discusses experimentation with optically induced phase change in nanoparticle liquid suspensions-commonly termed nanofluids. Four different types of nanofluids at five concentrations were exposed to a similar to 120 mW, 532 nm laser beam to determine the minimum laser flux needed to create vapor. Laser irradiance was varied between 0-770 W cm(-2). While the experiments were simple, they involved many complex, interrelated physical phenomena, including: subcooled boiling, thermal driven particle/bubble motion, nanoparticle radiative absorption/scattering, and nanoparticle clumping. Such phenomena could enable novel solar collectors in which the working fluid directly absorbs energy and undergoes phase change in a single step. c 2009 American Institute of Physics. [doi: 10.1063/1.3250174