low temperature is one of main factors limiting distribution of woody plants. in order to evaluate the resistance of 4-years old seedlings and adult trees of maclura pomifera to freezing stress, a factorial experiment was carried out based on completely randomized design with three replications in the faculty of agriculture, university of tehran. during 2012-2013 sampling were done from the ann...

The fact that freezing caused marked changes in oxidative activity of tissues was of comparatively little interest until it became apparent that most if not all the enzymatic activities of cells could be reproduced under suitable conditions in cell-free systems. Isolated soluble enzymes were usually unaffect,ed or even stabilized by freezing, and damaging effects of freezing on other enzymes co...

BACKGROUND Freezing is commonly used for food preservation. It is usually done under constant atmospheric pressure (isobaric). While extending the life of the produce, isobaric freezing has detrimental effects. It causes loss of food weight and changes in food quality. Using thermodynamic analysis, we have developed a theoretical model of the process of freezing in a constant volume system (iso...

BACKGROUND Controlled-rate freezing of ovarian cortical tissue for preservation of fertility among young women facing chemo- or radio-therapy is a widely accepted procedure. To improve the method for cryopreservation of ovarian tissue, particularly the stroma, we carried out a systematic comparison of vitrification versus slow programmed freezing. METHODS Ovarian tissue from 20 women, donated...

The ultrastructure in the beef muscle of the electro-magnetic resonance and air blast freezing during the frozen storage, and the changes in the quality characteristics after thawing were evaluated. The size of ice crystal was small and evenly formed in the initial freezing period, and it showed that the size was increased as the storage period was elapsed (p<0.05). The beef stored by the elect...

This study investigates the effects of the gelatin concentration (10-40%, w/v), freezing temperatures (from -20℃ to -50℃) and freezing methods on the structural and physical properties of gelatin matrices. To freeze gelatin, the pressure-shift freezing (PSF) is being applied at 0.1 (under atmospheric control), 50 and 100 MPa, respectively. The freezing point of gelatin solutions decrease with i...

background and objectives: cold stress is one of the most important limiting factor for growth and development of grasses in temperate regions. freezing tolerance is highly different between plant species and between regions. the importance of grasses is due to widespread application in lawn beautifying, animal feeding, and erosion control. there are many differences between grass species in re...

INTRODUCTION THE FREEZING PROCESS Frost Supercooling Freeze Desiccation Controlling the freezing process Acclimation to Freezing Stress Metabolic changes Sugars Lipids Abscisic acid The signalling cascade Mechanisms of Injury Sulphydryl-disulphide Hypothesis Expansion-induced Lysis Freeze-induced electrical transients Phase properties of the lipid bilayer Plasma membrane transport and ATPase Ox...

This study concerned the response to freezing of Neurospora crassa conidia in four different states: air-dry, hydrated in water, hydrated in Vogel medium lacking only sucrose, or hydrated in complete Vogel medium. All hydrated conidia were incubated in one of the above media for various times before freezing and were then washed and frozen in distilled water. Viability was estimated by three te...

The advanced stage of Parkinson's disease (PD) is characterised by complex movement disturbances including freezing. Because freezing is resistant to drug therapy, there has recently been renewed interest in non-pharmacological treatment programmes. In this study the effect of rotational stimulation on freezing was investigated. Eight patients with idiopathic PD and freezing participated in the...