Pressure

High pressure homogenization (HPH) was tested for inducing autolysis in a commercial strain of Saccharomyces bayanus for winemaking. The effects on cell viability, the release of soluble proteins, glucidic colloids and amino acids in wine-like medium and the volatile composition of the autolysates were investigated after processing, in comparison with thermolysis. HPH seemed a promising technique for inducing autolysis of wine yeasts. One pass at 150MPa was the best operating conditions. Soluble colloids, proteins and free amino acids were similar after HPH and thermolysis, but the former gave a more interesting volatile composition after processing, with higher concentrations of ethyl esters (fruity odors) and lower fatty acids (potential off-flavors). This might allow different winemaking applications for HPH, such as the production of yeast derivatives for wine ageing. In the conditions tested, HPH did not allow the complete inactivation of yeast cells; the treatment shall be optimized before winemaking use.

Acute infection of surgical incision sites often requires specialized wound care in preparation for surgical closure. Optimal therapy for preparing such wounds for a secondary closure procedure remains uncertain. The authors report wound outcomes after administering acoustic pressure wound therapy in conjunction with negative pressure wound therapy with reticulated open-cell foam dressing changes to assist with bacteria removal from open, infected surgical-incision sites in preparation for secondary surgical closure in three patients. Before incorporating acoustic pressure wound therapy at the authors' facility, the average negative pressure wound therapy with reticulated open-cell foam dressing course prior to secondary surgical closure was 30 days; with its addition, two of three patients underwent successful surgical closure with no postoperative complications after 21 and 14 days, respectively; one patient succumbed to nonwound-related complications before wound closure. Lar...

The effects of spinal cord injury (SCI) on esophageal motility are largely unknown. Furthermore, due to the complete or partial loss of sensory innervation to the upper gastrointestinal tract, a symptom-based diagnosis of esophageal dysmotility is problematic in the SCI population. To determine the prevalence and characterize the type of motility disorders observed in persons with chronic SCI compared with that of able-bodied (AB) controls based on esophageal pressure topography isometrics acquired by high-resolution manometry and categorized by application of the Chicago Classification. High-resolution manometry of the esophagus was performed in 39 individuals: 14 AB, 12 with paraplegia (level of injury between T4-T12) and 13 with tetraplegia (level of injury between C5-C7). A catheter containing multiple pressure sensors arranged at 360° was introduced into the esophagi of subjects at a distance that allowed visualization of both the upper esophageal sphincters (UES) and lower eso...

The velocity by which the disturbance travels through the medium is the wave velocity. Pulse wave velocity is one of the main parameters in hemodynamics. The study of wave propagation through the fluid-fill elastic tube is of great importance for the proper biophysical understanding of the nature of blood flow through of cardiovascular system. The effect of viscosity on the pulse wave velocity is generally ignored. In this paper we present the results of experimental measurements of pulse wave velocity (PWV) of compression and expansion waves in elastic tube. The solutions with different density and viscosity were used in the experiment. Biophysical model of the circulatory flow is designed to perform measurements. Experimental results show that the PWV of the expansion waves is higher than the compression waves during the same experimental conditions. It was found that the change in viscosity causes a change of PWV for both waves. We found a relationship between PWV, fluid density ...

Doxorubicin (DOX)-loaded water-in-oil-in-water (W/O/W) microemulsions were produced using a shirasu-porous-glass (SPG) membrane emulsification technique. Soybean oil was used as the oil phase; polyglycerol polyricinoleate (PGPR) or tetraglycerol polyricinoleate (TGPR) was used as the surfactant to stabilize the feed W/O emulsions, while Tween 20 was used in the external water phase to stabilize oil droplets containing water droplets. Increasing the feed pressure from 50 to 90 kPa increased the particle size of W/O/W emulsions, whereas it was decreased by increasing the agitator speed. The smallest particle sizes of multiple emulsions were obtained at the feed pressure of 50 kPa and agitator speed of 350 rpm. Under this set of conditions, the increase in the concentration of PGPR or TGPR showed a decrease in the particle size of DOX-loaded W/O/W emulsions. The optimized formulation comprising of 5% w/v PGPR and 3% w/v Tween 20 in the oil phase and external water phase, respectively, ...

We present a model of the mechanical and fluid forces associated with exudative retinal detachments where the retinal photoreceptor cells separate, typically from the underlying retinal pigment epithelium (RPE). By computing the total fluid volume flow arising from transretinal, vascular and RPE pump currents, we determine the conditions under which the subretinal fluid pressure exceeds the maximum yield stress holding

Respiratory mechanics, chest wall configuration, and lung morphometry were determined in rats before and at 30 (PTX.30) and 60 (PTX.60) min after pneumothorax induction (intrathoracic injection of 8 ml of room air; 50% collapse). Pneumothorax increased respiratory system and lung elastances and viscoelastic/inhomogeneous pressures in both groups, but respiratory system and lung resistive pressures increased only in PTX.60 group. Antero-posterior diameters at the third intercostal space and xiphoid levels, circumference at xiphoid level, and thoracic cephalo-caudal diameter increased significantly after pneumothorax induction independently of temporal evolution. In both groups lung collapse, hyperinflation, and interstitial and alveolar edema were present. Additionally, in PTX.60 group the central airways calibre diminished in relation to PTX.30. In conclusion pneumothorax yields changes in respiratory system and lung elastic and viscoelastic parameters, which are related to alveolar collapse and edema, respectively. Temporal evolution of pneumothorax also leads to changes in lung resistive pressure, probably because of airway narrowing.

To investigate the physiopathologic mechanisms of the rupture of the corpora cavernosa by means of a histologic study of the tunica albuginea. In 6 patients (age range 28 to 49 years, mean 38) with traumatic penile rupture, samples of the tunica albuginea were taken during corrective surgery far from the site of the lesion. These specimens were analyzed with light microscopy by the same pathologist and compared with other samples of tunica albuginea taken from 7 patients who underwent penile surgery for other reasons. Five of the 6 patients with traumatic penile rupture had histologic anomalies of the tunica albuginea (fibrosclerosis in all 5 patients [83%] and phlogistic cellular infiltrations composed of lymphocytes or histiocytes in 3 patients [50%]). Only 1 patient (17%) with traumatic rupture of the corpus cavernosum had a completely healthy tunica albuginea. None of the control specimens revealed any histologic alterations. Structural anomalies could alter the mechanical prope...