Search results for "Pressure"

Chronic Adult Hydrocephalus

1974

Knowledge of Wallerian degeneration began in 1852 and, following experimental research on degeneration and regeneration of interrupted nerves, surgeons realized that reinnervation of end organs depended on growth of axons through the interrupted area of nerve. Therefore surgeons tried to reanastomose the stumps. Failures of reinnervation could not be blamed on lack of axoplasma metabolism and flow from cell body to suture line because the clinical observation of amputation neuromas and their constant recurrence demonstrated the unfailing delivery of axoplasma by the nerve cell body; at times to the deep concern of the surgeon, and the constant pain of the patient. The electron microscope sh…

Water in Dairy Products | Analysis and Measurement of Water Activity

2011

Water activity of a system (aw) is a thermodynamic concept used to characterize the contained water. It has been considered, in spite of some limitations, as the most important parameter in food technology for the past 50 years. It can be measured by the ratio (p/p0) of the water vapor pressure in the atmosphere at equilibrium with the material to the saturated vapor pressure of pure water at the same temperature, or by the physical properties related to it (freezing point depression, mechanical/electrical properties). Although the physical/chemical mechanisms responsible for the depression of aw as compared to that of pure water are more or less identified, the expressions describing the r…

Synergistic and Antagonistic Effects of Combined Subzero Temperature and High Pressure on Inactivation of Escherichia coli

2006

ABSTRACT The combined effects of subzero temperature and high pressure on the inactivation of Escherichia coli K12TG1 were investigated. Cells of this bacterial strain were exposed to high pressure (50 to 450 MPa, 10-min holding time) at two temperatures (−20°C without freezing and 25°C) and three water activity levels (a w ) (0.850, 0.992, and ca. 1.000) achieved with the addition of glycerol. There was a synergistic interaction between subzero temperature and high pressure in their effects on microbial inactivation. Indeed, to achieve the same inactivation rate, the pressures required at −20°C (in the liquid state) were more than 100 MPa less than those required at 25°C, at pressures in t…

Unsaturated Soil Hydraulic Properties

2016

In the first part of this chapter, the tension infiltrometer (TI) technique is illustrated. After having described apparatus and instruments as well as the operative procedures in the field, the solutions based on the Wooding’s equation for steady-state flow are presented. Specific focus is given to the multi-potential approaches that allow determination of unsaturated soil hydraulic conductivity, K 0, corresponding to a sequence of pressure head values, h 0, imposed on the soil surface. The analytical model proposed by Haverkamp et al. (1994) to describe three-dimensional transient infiltration from a circular source is introduced and a single-test approach is presented that allows estimat…

Saturated Soil Hydraulic Conductivity

2016

This chapter deals primarily with field measurement of saturated soil hydraulic conductivity, K fs . Well or borehole permeameter techniques, specifically developed for subsurface soil measurements above the water table, are initially illustrated. Particular attention is paid to establishment of steady flow under constant head in an uncased borehole, widely developed both theoretically and experimentally in the last 30 years. Situations involving cased boreholes, transient flow, or falling head processes are then described. These variants have received a renewed interest in the last few years. New data analysis procedures have been proposed and this circumstance allows us to obtain subsurfa…

Losing weight after menopause with minimal aerobic training and mediterranean diet

2020

Objective: It is a common belief that menopausal women have greater difficulty losing weight. The aim of this study was to assess the efficacy of a Mediterranean diet (MD) to promote weight loss in postmenopausal women. All participants were prescribed a hypocaloric traditional MD, tailored to the individual. Subjects were asked not to begin any kind of physical activity. Body composition was measured at the beginning and after 8 weeks of treatment. In total, 89 women (age 52.8 &plusmn

Determination of 5-nitrofurylacrylic acid in wines by high-performance liquid chromatography

1988

Expressing forest origins in the chemical composition of cooperage oak woods and corresponding wines by using FTICR-MS.

2008

A non-targeted, ultra-high-resolution mass spectrometric, direct analysis of oak-wood extracts from two species (Quercus robur L. and Quercus petraea Liebl.) from three French forests, and of a wine aged in barrels derived therefrom has been performed to identify families of metabolites that could discriminate both the species and the geographical origin of woods. From 12 T ultra-high-resolution Fourier transform ion cyclotron resonance mass spectra of wood extracts, hundreds of mass signals were identified as possible significant biomarkers of the two species, with phenolic and carbohydrate moieties leading the differentiation between Q. robur and Q. petraea, respectively, as corroborated …

Red Wine and Cardiovascular Health

2012

There is strong epidemiological evidence that light-to-moderate consumption of alcoholic drinks, but neither zero nor more than moderate intake, reduces mortality from all causes and also diminishes cardiovascular risk.1 The lowest risk for coronary heart disease mortality is seen with 1 to 2 drinks (12.5–25g alcohol) per day. Article, see p 1065 Hypertension is a major risk factor for cardiovascular disease, and there is a clear inverse relationship between light-to-moderate alcohol intake and blood pressure. Thus, the reduced cardiovascular risk associated with moderate consumption of alcoholic drinks may be due, in part, to a reduction in blood pressure. The greatest blood pressure benef…

Purification method for the isolation of monophosphate nucleotides from Champagne wine and their identification by mass spectrometry

2001

Monophosphate nucleotides are difficult to identify in Champagne wine because they are present in small concentrations in a complex mixture. A method for the isolation, separation and identification of reference compounds, which achieved on average 79% recovery (except for cytidine derivatives), was developed and applied to wine. Some monophosphate nucleotides were then isolated from a Champagne wine aged on lees for 8 years, by ultrafiltration followed by a semi-preparative HPLC step using a strong anion-exchange column. The fraction obtained was subjected to HPLC in a reversed-phase column to remove the salt previously introduced, before identification of compounds by HPLC coupled to a ma…