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in subjects: "Cryobiology"  
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SEM and x-ray microanalysis of cellular differentiation in Sea Urchin Embryos: a frozen hydrated study

Description: Quantitative studies of major chemical element distribution among individual differentiating cells were attempted using scanning electron microscopy. Frozen hydrated embryos of the sea urchin Strongelocentrotus purpuratus were examined at three stages: blastula, mesenchyme blastula, and early gastrula. The blastocoel matrix contained large beads of approximately 1 ..mu..m diameter. The cells of the archenteron lacked well defined cell boundaries. Characteristic levels of beam damage and chargin… more
Date: December 1, 1985
Creator: Klein, S.B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Effects of freezing and cold acclimation on the plasma membrane of isolated protoplasts

Description: Our goal is to provide a mechanistic understanding of the cellular and molecular aspects of freezing injury and cold acclimation from a perspective of the structural and functional integrity of the plasma membrane -- the primary site of freezing injury in winter cereals. We have utilized protoplasts isolated from leaves of winter rye (Secale cereale L. cv Puma) to study the cryobehavior of the plasma membrane during a freeze/thaw cycle. The focus of our current studies is on lesions in the plas… more
Date: January 1, 1993
Creator: Steponkus, P.L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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ESR (electron spin resonance)-determined osmotic behavior of bull spermatozoa

Description: Our laboratories are pursuing a fundamental approach to the problems of semen cryopreservation. For many cell types (human red cells, yeast, HeLa) it has been demonstrated that there is an optimum cooling rate for cryopreservation. Faster rates allow insufficient time for cell dehydration and result in intracellular ice formation and cell death. It is possible to predict this optimal rate provided that the cell acts as an ideal osmometer and several other cell parameters are known such as the m… more
Date: January 1, 1990
Creator: Du, J.; Kleinhans, F.W.; Spitzer, V.J.; Critser, J.K. (Methodist Hospital, Indianapolis, IN (USA). Dept. of Medical Research); Horstman, L. (Purdue Univ., Lafayette, IN (USA). School of Veterinary Medicine) & Mazur, P. (Oak Ridge National Lab., TN (USA))
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Effects of freezing and cold acclimation on the plasma membrane of isolated protoplasts

Description: This project focuses on lesions in the plasma membrane of protoplasts that occur during freezing to temperatures below {minus}5{degrees} which result in changes in the semipermeablity of the plasma membrane. This injury, referred to as loss of osmotic responsiveness, is associated with the formation of large, aparticulate domains in the plasma membrane, aparticulate lamellae subtending the plasma membrane, and lamellar-to-hexagonal{sub II} phase transitions in the plasma membrane and subtending… more
Date: January 1, 1991
Creator: Steponkus, P. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Effects of freezing and cold acclimation on the plasma membrane of isolated protoplasts. Progress report, May 16, 1992--January 9, 1993

Description: Our goal is to provide a mechanistic understanding of the cellular and molecular aspects of freezing injury and cold acclimation from a perspective of the structural and functional integrity of the plasma membrane -- the primary site of freezing injury in winter cereals. We have utilized protoplasts isolated from leaves of winter rye (Secale cereale L. cv Puma) to study the cryobehavior of the plasma membrane during a freeze/thaw cycle. The focus of our current studies is on lesions in the plas… more
Date: May 1, 1993
Creator: Steponkus, P. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Effects of freezing and cold acclimation on the plasma membrane of isolated protoplasts. Summary progress report, May 16, 1987--June 1, 1991

Description: This project focuses on lesions in the plasma membrane of protoplasts that occur during freezing to temperatures below {minus}5{degrees} which result in changes in the semipermeablity of the plasma membrane. This injury, referred to as loss of osmotic responsiveness, is associated with the formation of large, aparticulate domains in the plasma membrane, aparticulate lamellae subtending the plasma membrane, and lamellar-to-hexagonal{sub II} phase transitions in the plasma membrane and subtending… more
Date: December 31, 1991
Creator: Steponkus, P. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Procedure for the permeabilization and cryobiological preservation of Drosophila embryos

Description: The authors describe the detailed protocol developed in their laboratory at Oak Ridge for the permeabilization and cryobiological preservation of embryos of Drosophila melanogaster, Oregon R strain. The protocol is supplemented by notes containing two sorts of information. One category includes references to the appropriate portions of their published papers giving the scientific rationale and experimental basis for important steps. The other category is concerned with the criticality of certai… more
Date: May 6, 1993
Creator: Cole, K. W.; Schreuders, P. D.; Mahowald, A. P. & Mazur, Peter
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Critical tonicity determination of sperm using fluorescent staining and flow cytometry

Description: The use of cryopreserved, rather than fresh, mammalian semen for artificial insemination confers several important medical and/or economic advantages. However, current methods for cryopreservation of both human and bovine spermatozoa result in approximately only a 50% survival rate with thawing, obviously reducing the fertilizing capacity of the semen. A primary consideration during the cooling process is to avoid intracellular ice crystal formation with its lethal consequences to the cell. Cur… more
Date: January 1, 1990
Creator: Noiles, E.E.; Ruffing, N.A.; Kleinhans, F.W.; Mark, L.A.; Watson, P.F.; Critser, J.K. (Methodist Hospital, Indianapolis, IN (USA)) et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Application of spectral hole burning to the study of in vitro cellular systems

Description: Chapter 1 of this thesis describes the various stages of tumor development and a multitude of diagnostic techniques used to detect cancer. Chapter 2 gives an overview of the aspects of hole burning spectroscopy important for its application to the study of cellular systems. Chapter 3 gives general descriptions of cellular organelles, structures, and physical properties that can serve as possible markers for the differentiation of normal and cancerous cells. Also described in Chapter 3 are the p… more
Date: November 8, 1999
Creator: Milanovich, Nebojsa
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
open access

Biophysical and biological factors determining the ability to achieve long-term cryobiological preservation

Description: The BESTCapsule will maintain appropriate biological specimens for decades or centuries at cryogenic temperatures in the living state. Maintenance at temperatures below {approximately} {minus}140 C is not a problem. No ordinary chemical reactions in aqueous solutions can occur. The only source of damage will be the slow accumulation of physical damage to DNA from background ionizing radiation. But this source of damage should not become serious in less than a millennium. Rather, the main proble… more
Date: December 1, 1997
Creator: Mazur, P.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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