OBJECTIVE: Pressure-ulcer occurrence in the seated patient is understudied. Preventative devices have been developed and are prescribed commonly, but there is little quantitative evidence of their effectiveness. This study explores the concept of a lateral pressure device, a prevention device that applies pressure to the sides of the seated buttocks, to reduce the amount of tissue distortion and blood-vessel occlusion. It is hypothesized that this device will reduce deep tissue injury by reducing the pressure at the bone-muscle interface, as demonstrated computationally in previous research. This study aimed to use oximetry to investigate the efficacy of the device in maintaining transcutaneous gas tensions of the tissue as close to baseline as possible.
METHODS: Oximetry electrodes were attached to participants\' ischial tuberosity and greater trochanter for different amounts of lateral pressure. The amount of lateral pressure is a given percentage of the pressure due to the participants\' underbody pressure.
RESULTS: The results show that 50 % lateral pressure is sufficient to produce an improvement in participants\' gas tensions at their ischial tuberosity, without negatively impacting the tissue at their greater trochanter, relative to the control of sitting with no application of lateral pressure.
CONCLUSIONS: Despite a rudimentary prototype device design, and that participants each placed their own oximetry sensors, results support the application of lateral pressure as a method to maintain transcutaneous gas tensions. Further work should be carried out on a larger sample to consolidate these findings.

To explore the effect of different stress environments on fault-slip rockbursts. Bidirectional shear friction experiments with different lateral pressures were conducted on precracked syenogranites buried at 800 m. The macroscopic statistical parameters (cumulative number of AE events, magnitude and b value) and local characteristic parameters (amplitude and dominant frequency) of acoustic emission during the stick-slip process under different lateral pressures were investigated. In addition, based on fractal theory, the nonlinear characteristics of AE spectrum were analyzed. On this basis, the microscopic mechanism of fault stick-slip was discussed. The results show that the lateral pressure influences the friction strength of the fault and stick-slip motion characteristics. With increasing lateral pressure, the proportion of transgranular shear fractures increases, which leads to an increase of cumulative number of AE events and magnitude. The periodic decrease in the b value is more significant at high lateral pressure. There is a good correlation between a high-magnitude AE event and a stress drop. The AE frequency with phased response characteristics can be used to effectively identify the evolution of fault stick-slip instability at the laboratory scale. A sharp increase in the amplitude of the dominant frequency can be regarded as one of the precursory features of fault stick-slip instability. The AE frequency spectra have multifractal characteristics, that differ among the different stages. The maximum multifractal dimension and spectral width can reflect the difference in energy released during fault stick-slip motion.

The clinical benefits of using exogenous pulmonary surfactant (EPS) as a carrier of budesonide (BUD), a non-halogenated corticosteroid with a broad anti-inflammatory effect, have been established. Using various experimental techniques (differential scanning calorimetry DSC, small- and wide- angle X-ray scattering SAXS/WAXS, small- angle neutron scattering SANS, fluorescence spectroscopy, dynamic light scattering DLS, and zeta potential), we investigated the effect of BUD on the thermodynamics and structure of the clinically used EPS, Curosurf®. We show that BUD facilitates the Curosurf® phase transition from the gel to the fluid state, resulting in a decrease in the temperature of the main phase transition (Tm) and enthalpy (ΔH). The morphology of the Curosurf® dispersion is maintained for BUD < 10 wt% of the Curosurf® mass; BUD slightly increases the repeat distance d of the fluid lamellar phase in multilamellar vesicles (MLVs) resulting from the thickening of the lipid bilayer. The bilayer thickening (~0.23 nm) was derived from SANS data. The presence of ~2 mmol/L of Ca2+ maintains the effect and structure of the MLVs. The changes in the lateral pressure of the Curosurf® bilayer revealed that the intercalated BUD between the acyl chains of the surfactant\'s lipid molecules resides deeper in the hydrophobic region when its content exceeds ~6 wt%. Our studies support the concept of a combined therapy utilising budesonide-enriched Curosurf®.

Oseltamivir belongs to the neuraminidase inhibitors, developed against the influenza virus, and registered under the trademark Tamiflu. Despite its long-term acquaintance, there is limited information in the literature about its physicochemical and structural properties in a lipid-water system. We present an experimentally determined partition coefficient with structural information on the interaction of oseltamivir with the model membrane, its possible location, and its effect on the membrane thermodynamics. The hydrophobic part of the lipid bilayer is affected to a moderate extent, which was proved by slight changes in thermal and structural properties. Hereby, interaction of oseltamivir with the phospholipid bilayer induces concentration dependent decrease of lateral pressure in the bilayer acyl chain region. Oseltamivir charges the bilayer surface positively, which results in the zeta potential increase and changes in anisotropic properties studied by the polarised light microscopy. At the highest oseltamivir concentrations studied, the multilamellar structure is extensively disturbed, likely due to electrostatic repulsion between the adjacent bilayers.

This study evaluated the effects of increased temperature and leachate recirculation on volatile solids (VS), biogas, hydrogen sulphide (H2S) leachate quality (pH and chemical oxygen demand) and the settlement of municipal solid waste (MSW). Three large-scale tests were conducted with no leachate recirculation at 21°C, weekly leachate recirculation at 20°C and weekly leachate recirculation at 50°C. Leachate recirculation and increased temperature accelerated biodegradation and pushed forward the onset time (from 27 to 8 days). The increase of biodegradation activity was reflected in the change of biogas production, VS and settlement. Compressibility index Cc, increased from 0.71 and 0.77 at 21°C to 0.83 when the temperature was 50°C. In addition, leachate recirculation and high temperature reduced H2S concentration levels by inhibiting the growth of sulphate-reducing bacteria and leachate recirculation lowered H2S production by dissolving the high H2S presence. The results showed that MSW can have significantly changed mechanical and biochemical behaviour under different temperatures and saturations. The results help understand the processes in landfills for more effective short-term and long-term design and management.

It is well known that lipids neighboring integral membrane proteins directly influence their function. The opposite effect is true as well, as membrane proteins undergo structural changes after activation and thus perturb the lipidic environment. Here, we studied the interaction between these molecular machines and the lipid bilayer by observing changes in the lipid vibrational bands via FTIR spectroscopy. Membrane proteins with different functionalities have been reconstituted into lipid nanodiscs: Microbial rhodopsins that act as light-activated ion pumps (the proton pumps NsXeR and UmRh1, and the chloride pump NmHR) or as sensors (NpSRII), as well as the electron-driven cytochrome c oxidase RsCcO. The effects of the structural changes on the surrounding lipid phase are compared to mechanically induced lateral tension exerted by the light-activatable lipid analogue AzoPC. With the help of isotopologues, we show that the ν(C = O) ester band of the glycerol backbone reports on changes in the lipids\' collective state induced by mechanical changes in the transmembrane proteins. The perturbation of the nanodisc lipids seems to involve their phase and/or packing state. 13C-labeling of the scaffold protein shows that its structure also responds to the mechanical expansion of the lipid bilayer.

Langmuir monolayers can be assembled from molecules that change from a low-energy orientation occupying a large cross-sectional area to a high-energy orientation of small cross-sectional area as the lateral pressure grows. Examples include cyclosporin A, amphotericin B, nystatin, certain alpha-helical peptides, cholesterol oxydation products, dumbbell-shaped amphiphiles, organic-inorganic nanoparticles and hybrid molecular films. The transition between the two orientations leads to a shoulder in the surface pressure-area isotherm. We propose a theoretical model that describes the shoulder and can be used to extract the energy cost per molecule for the reorientation. Our two-state model is based on a lattice-sublattice approximation that hosts the two orientations and a corresponding free energy expression which we minimize with respect to the orientational distribution. Inter-molecular interactions other than steric repulsion are ignored. We provide an analysis of the model, including an analytic solution for one specific lateral pressure near a point of inflection in the surface pressure-area isotherm, and an approximate solution for the entire range of the lateral pressures. We also use our model to estimate energy costs associated with orientational transitions from previously reported experimental surface pressure-area isotherms.

This research deals with the stability analysis of shallow segments of the toroidal shell made of saturated porous functionally graded (FG) material. The nonhomogeneous material properties of porous shell are assumed to be functionally graded as a function of the thickness and porosity parameters. The porous toroidal shell segments with positive and negative Gaussian curvatures and nonuniform distributed porosity are considered. The nonlinear equilibrium equations of the porous shell are derived via the total potential energy of the system. The governing equations are obtained on the basis of classical thin shell theory and the assumptions of Biot\'s poroelasticity theory. The equations are a set of the coupled partial differential equations. The analytical method including the Airy stress function is used to solve the stability equations of porous shell under mechanical loads in three cases. Porous toroidal shell segments subjected to lateral pressure, axial compression, and hydrostatic pressure loads are analytically analyzed. Closed-form solutions are expressed for the elastic buckling behavior of the convex and concave porous toroidal shell segments. The effects of porosity distribution and geometrical parameters of the shell on the critical buckling loads of porous toroidal shell segments are studied.

Nikolsky\'s sign has been a very useful diagnostic tool in cases of skin disorders like pemphigus, toxic epidermal necrolysis, etc., The sign is demonstrated when lateral pressure is applied on the border of an intact blister, which results in the dislodgment of the normal epidermis and extension of the blister.

Photoelectric integrated testing technology was used to study precast piles during pile jacking at the pile-soil interface considering the influence of the earth and pore water pressures on its vertical bearing performance. The low temperature sensitive fiber Bragg grating (FBG) strain sensors and miniature silicon piezoresistive sensors were implanted in the model pile to test the changes of earth pressure, pore water pressure and pile axial force of the jacked pile at the pile-soil interface, and the influence of lateral pressure on pile axial force was studied. The test results showed that the nylon rod is feasible as a model pile. The FBG strain sensor had a stable performance and monitored changes in the axial force of the model pile in real time. The miniature earth and pore water pressure sensors were small enough to avoid size effects and accurately measured changes in the earth and pore water pressures during the pile jacking process. During pile jacking, the lateral earth pressure increased gradually in depth, and the lateral earth pressure at the same depth tended to decrease at greater depths. Lateral pressures caused the axial force of the pile to increases by a factor of 1-2, where the maximum was 2.7. Therefore, the influence of the lateral pressure must be considered when studying the residual pile stress.