Temperature-Dependent Re-alignment of the Short Multifunctional Peptide BP100 in Membranes Revealed by Solid-State NMR Spectroscopy and Molecular Dynamics Simulations

BP100 is a cationic undecamer peptide with antimicrobial and cell-penetrating activities. The orientation of this amphiphilic α-helix in lipid bilayers was examined under numerous conditions using solid-state ¹⁹F, ¹⁵N and ²H NMR. At high temperatures in saturated phosphatidylcholine lipids, BP100 lies flat on the membrane surface, as expected. Upon lowering the temperature towards the lipid phase transition, the helix is found to flip into an upright transmembrane orientation. In thin bilayers, this inserted state was stable at low peptide concentration, but thicker membranes required higher peptide concentrations. In the presence of lysolipids, the inserted state prevailed even at high temperature. Molecular dynamics simulations suggest that BP100 monomer insertion can be stabilized by snorkeling lysine side chains. These results demonstrate that even a very short helix like BP100 can span (and thereby penetrate through) a cellular membrane under suitable conditions.     

Oxidative stress, genotoxicity, and vascular cell adhesion molecule expression in cells exposed to particulate matter from combustion of conventional diesel and methyl ester biodiesel blends

Our aim was to compare hazards of particles from combustion of biodiesel blends and conventional diesel (D(100)) in old and improved engines. We determined DNA damage in A549 cells, mRNA levels of CCL2 and IL8 in THP-1 cells, and expression of ICAM-1 and VCAM-1 in human umbilical cord endothelial cells (HUVECs). Viability and production of reactive oxygen species (ROS) were investigated in all cell types. We collected particles from combustion of D(100) and 20% (w/w) blends of animal fat or rapeseed oil methyl esters in light-duty vehicle engines complying with Euro2 or Euro4 standards. Particles emitted from the Euro4 engine were smaller in size and more potent than particles emitted from the Euro2 engine with respect to ROS production and DNA damage, but similarly potent concerning cytokine mRNA expression. Particles emitted from combustion of biodiesel blends were larger in size, and less or equally potent than particles emitted from combustion of D(100) concerning ROS production, DNA damage and mRNA of CCL2 and IL8. ICAM-1 and VCAM-1 expression in HUVECs was only increased by D(100) particles from the Euro4 engine. This suggests that particle emissions from biodiesel in equal mass concentration are less toxic than conventional diesel.     

AUTO-SMASH: A self-calibrating technique for SMASH imaging

Recently a new fast magnetic resonance imaging strategy, SMASH, has been described, which is based on partially parallel imaging with radiofrequency coil arrays. In this paper, an internal sensitivity calibration technique for the SMASH imaging method using self-calibration signals is described. Coil sensitivity information required for SMASH imaging is obtained during the actual scan using correlations between undersampled SMASH signal data and additionally sampled calibration signals with appropriate offsets ink-space. The advantages of this sensitivity reference method are that no extra coil array sensitivity maps have to be acquired and that it provides coil sensitivity information in areas of highly non-uniform spin-density. This auto-calibrating approach can be easily implemented with only a small sacrifice of the overall time savings afforded by SMASH imaging. The results obtained from phantom imaging experiments and from cardiac studies in nine volunteers indicate that the self-calibrating approach is an effective method to increase the potential and the flexibility of rapid imaging with SMASH.     

Cross validation of the MacNeill-Lichtenberg Decision Tree: Triaging mental health problems in geriatric rehabilitation patients.

Objective: Cross validation of the MacNeill-Lichtenberg Decision Tree (MLDT), a tool for triaging mental health problems in older medical patients. Design: Sensitivity, specificity, and predictive power were calculated for prediction of cognition and depressive symptoms. Correlational analyses were performed to examine the relationship between demographic variables and MLDT measures. Correlational and logistic regression analyses were conducted to examine the utility of the cognitive component of the MLDT. Setting: A freestanding urban, university-affiliated rehabilitation hospital in the Midwest. Participants: One hundred eighty-seven elderly, predominantly African American medical rehabilitation patients who lived alone before hospitalization. Main Outcome Measure: The MLDT was compared with the Mattis Dementia Rating Scale and the 30-item Geriatric Depression Scale. Results: The cognitive component of the MLDT demonstrated high positive and negative predictive value; the affective component evidenced excellent negative predictive value. Conclusions: These findings are consistent with previous research and provide further evidence of the utility of the MLDT… (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

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Subacute rehabilitation: New opportunities and challenges for rehabilitation psychologists.

Changes in the health care delivery system have obliged rehabilitation service providers to consider alternatives to the traditional model of comprehensive acute inpatient rehabilitation. An option of growing popularity among third-party payers is subacute rehabilitation. This type of rehabilitation is usually provided within a skilled nursing home, provides fewer hours of therapeutic intervention, and uses less professional staff, but may achieve similar outcomes. As subacute rehabilitation has grown, rehabilitation psychologists have been used in these settings, but uncertainties exist as to appropriate roles and reimbursement opportunities. This article provides a framework for understanding the current status of subacute rehabilitation as a part of the rehabilitation continuum of care and how rehabilitation psychologists can maximize their effectiveness in this environment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A transmitter IC for TETRA systems based on a Cartesian feedback loop linearization technique

A fully integrated linearized transmitter for the next generation TETRA systems for PMR and public safety applications in a CMOS-based SiGe technology is described. The presented single-chip transmitter employs a Cartesian feedback loop technique in order to improve the linearity of the externally connected power amplifier. The transmitter is usable in a frequency range from 300 MHz up to 800 MHz, providing a linearity improvement of more than 40 dB.     

Marginal costs and co-benefits of energy efficiency investments: The case of the Swiss residential sector

Key elements of present investment decision-making regarding energy efficiency of new buildings and the refurbishment of existing buildings are the marginal costs of energy efficiency measures and incomplete knowledge of investors and architects about pricing, co-benefits and new technologies. This paper reports on a recently completed empirical study for the Swiss residential sector. It empirically quantifies the marginal costs of energy efficiency investments (i.e. additional insulation, improved window systems, ventilation and heating systems and architectural concepts). For the private sector, first results on the economic valuation of co-benefits such as improved comfort of living, improved indoor air quality, better protection against external noise, etc. may amount to the same order of magnitude as the energy-related benefits are given. The cost–benefit analysis includes newly developed technologies that show large variations in prices due to pioneer market pricing, add-on of learning costs and risk components of the installers. Based on new empirical data on the present cost-situation and past techno-economic progress, the potential of future cost reduction was estimated applying the experience curve concept. The paper shows, for the first time, co-benefits and cost dynamics of energy efficiency investments, of which decision makers in the real estate sector, politics and administrations are scarcely aware.