After freezing and thawing, Pseudomonas aeruginosa harboring a drug resistance plasmid (Hg , Strep ), became acutely sensitive to mercuric ions but not to streptomycin in the plating medium. Its sensitivity to both agents in the plating medium became more pronounced, suggesting a synergistic effect of the mercuric ions with streptomycin. This freeze-thaw-induced sensitivity was transient and ca...

In a study of human milk collected for banking, heating at 62.5 degrees C for 30 min, and freezing and thawing resulted in hydrolysis of triglycerides. Freezing and thawing caused disruption of fat globules and a greater hydrolysis of triglycerides than did the heating process. There was a decrease in the percentage of the poly-unsaturated fatty acids linoleic acid (C18:2) and linolenic acid (C...

introduction: sperm cryopreservation is widely used as a way of preserving the male sperm used in future artificial insemination and fertilization. despite all the recent advances in cryopreservation technology, sperm motility is negatively affected by freezing and the thawing afterwards. yet hyaluronic acid is believed to improve the vitality and motility of the sperm, enhancing the physiologi...

Since James Thomson et al developed a technique in 1998 to isolate and grow hES in culture, freezing cells for later use and thawing and expanding cells from a frozen stock have become important procedures performed in routine hES cell culture. Since hES cells are very sensitive to the stresses of freezing and thawing, special care must taken. Here we demonstrate the proper technique for rapidl...

We report on the preparation of both porous and non-porous poly(vinyl alcohol) (PVA) hydrogels that can be used as carriers to release proteins. Non-porous gels were prepared by freezing and thawing of aqueous PVA solutions, while porous gels were formed by adding porosigens such as NaCl or ammonium carbamate into aqueous PVA solutions. Bovine serum albumin, a model protein, was loaded into non...

Reactive oxygen species (ROS) generation, induced by the cryopreservation process, can be responsible for mammalian sperm damage. Curcumin is known as an effective antioxidant against oxidative stress. The aim of this study was to evaluate the effects of curcumin on sperm count, motility and viability, semen total antioxidant capacity and DNA integrity of rat spermatozoa during semen freeze-tha...

Litter decomposition during winter can provide essential nutrients for plant growth in the subsequent growing season, which plays important role in preventing the expansion of dry areas and maintaining the stability of ecotone ecosystems. However, limited information is currently available on the contributions of soil fauna to litter decomposition during winter in such ecosystems. Therefore, a ...

Understanding the fates of soil hydrological processes and nitrogen (N) is essential for optimizing the water and N in a dryland crop system with the goal of obtaining a maximum yield. Few investigations have addressed the dynamics of dryland N and its association with the soil hydrological process in a freeze-thawing agricultural area. With the daily monitoring of soil water content and acquis...

Ovarian tissue banking is a developing technique aimed to preserve fertility in women at risk for premature ovarian failure (1–3). It entails cryopreservation of ovarian tissue with the option of autografting. Reports on the autografting of cryopreserved ovarian cortex segments describe the resumption of steroid production (4), follicle development (5, 6), and (in sheep) model successful pregna...