The release of hydrogen cyanide from Amelanchier alnifolia was monitored at 30 C and -10 C following lethal freezing at both slow and fast rates. Assuming that hydrogen cyanide release indicates membrane damage, it was concluded that during a fatal freeze-thaw cycle membrane damage occurred during cell contraction and, therefore, was not dependent upon membrane area expansion during thawing.

Carnauba (Copernicia prunifera (Mill.) H.E. Moore) is a fruit of the Brazilian Caatinga and Cerrado regions. It has good nutritional characteristics, bioactive compounds, antioxidant activity. However, some processing techniques can affect its chemical characteristics. This study aims at evaluating effect freezing freeze-drying on compounds activity carnauba pulp. The pulp was submitted to thre...

The source region of solar wind plasma is observed to be directly reflected in the compositional pattern of both elemental and charge state compositions. Slow solar wind associated with streamers shows higher freeze-in temperatures and larger FIP enhancements than coronal hole associated wind. Also, the variability of virtually all compositional parameters is much higher for slow solar wind com...

In this study we heated insoluble residues, obtained after Triton-X-100 (0.1 v/v%) extraction of erythrocyte ghost membranes (EGMs). Specific heat capacity, electric capacitance and resistance, and optical transmittance (280 nm) sustained sharp changes at 49°C (TA) and 66°C (TC), the known denaturation temperatures of spectrin and band 3, respectively. The change at TA was selectively inhibited...

Meniscus allografting has provided relief of meniscal injuries that were previously thought irreparable. However, meniscus allograft tissue remains limited and a significant problem. To improve allograft tissue yield, decrease processing costs, and increase graft availability, this study investigated the biomechanical changes of meniscal allograft tissue frozen and thawed multiple times. Specif...

BACKGROUND Ovarian tissue banking is an emerging strategy for fertility preservation which has led to several viable pregnancies after transplantation. However, the standard method of slow cooling was never rigorously optimized for human tissue nor has the extent and location of ice crystals in tissue been investigated. To address this, we used cryo-scanning electron microscopy (cryo-SEM) to st...

1. Microsomes were isolated from rabbit fast-twitch and slow-twitch muscle and were separated into heavy and light fractions by centrifugation in a linear (0.3-2m) sucrose density gradient. The membrane origin of microsomal vesicles was investigated by studying biochemical markers of the sarcoplasmic-reticulum membranes and of surface and T-tubular membranes, as well as their freeze-fracture pr...

Sperm storage via freezing has been useful for men who have difficulty masturbating during assisted reproductive technology (ART) programs and before impotency caused by chemotherapy, vasectomy, and other procedures. Studies were undertaken to evaluate the extent of cryoinjury to sperm after repeated freezing and thawing. The results showed that normozoospermic and oligozoospermic sperm survive...

In recent years, improvements in transmission electron microscopy (TEM) techniques and the use of tomography have provided a more accurate view of the complexity of the ultrastructure of prokaryotic cells. Cryoimmobilization of specimens by rapid cooling followed by freeze substitution (FS) and sectioning, freeze fracture (FF) and observation of replica, or cryoelectron microscopy of vitreous s...