| 1. |
- Cöster, Lars, et al.
(författare)
-
Structure of proteoheparan sulfates from fibroblasts. Confluent and proliferating fibroblasts produce at least three types of proteoheparan sulfates with functionally different core proteins
- 1986
-
Ingår i: Journal of Biological Chemistry. - 1083-351X. ; 261:26, s. 12079-12088
-
Tidskriftsartikel (refereegranskat)abstract
- [3H]Leucine- and [35S]sulfate-labeled proteoheparan sulfates were isolated from postconfluent or proliferating cultures of human skin fibroblasts. Cell layers were solubilized by Triton X-100, and transferrin-binding macromolecules were isolated by affinity chromatography. Proteoglycans with no affinity for transferrin were purified by using ion-exchange and gel permeation chromatography. Postconfluent cells synthesize a proteoheparan sulfate of Mr 350,000 (as determined by gel permeation chromatography) which has affinity for transferrin as well as for octyl-Sepharose. Its core protein (Mr 180,000) consists of two disulfide-bonded polypeptides of Mr 90,000. This species was not detected in cultures of proliferating cells. Proliferating and confluent cells also synthesize other forms of proteoheparan sulfates (Mr 200,000-400,000) which have no affinity for transferrin. However, most of them have affinity for octyl-Sepharose. The core protein of proteoheparan sulfates made by proliferating cells has Mr 50,000. A smaller form (Mr 250,000) of this proteoglycan was solubilized by Triton X-100, whereas a larger form (Mr 400,000) remained associated with the pericellular matrix. A third type of proteoheparan sulfate (Mr 200,000) without affinity for transferrin nor octyl-Sepharose was associated with postconfluent cell layers but not with proliferating ones. Its core protein has Mr 35,000. Heparan sulfate oligosaccharides (Mr 6,000 or higher) were found in proliferating cells but not in postconfluent ones.
|
|
| 2. |
- Fransson, Åke, et al.
(författare)
-
Automated differential scanning calorimetry at low temperatures
- 1985
-
Ingår i: International journal of thermophysics. - : Plenum Publishing. - 0195-928X .- 1572-9567. ; 6:2, s. 165-175
-
Tidskriftsartikel (refereegranskat)abstract
- A Perkin-Elmer DSC-2 scanning calorimeter was operated by means of a PDP-11/34 computer with time-shared scanner and voltmeter. Special attention was paid to the problems of measurement below room temperature down to the low-temperature limit. It was found that Ne, rather than He, should be used as a purge gas, that scans should always be started at a standardized liquid nitrogen level, and that gas flow to the dry box should be stopped during measurements. Results on benzoic acid were then accurate to 0.6 % from 120 to 300 K. The specific heat of antimony was measured in the temperature interval 120–720 K.
|
|
| 3. |
- Fransson, Åke, et al.
(författare)
-
Isothermal enthalpy relaxation of glassy 1,2,6-hexanetriol
- 1987
-
Ingår i: Molecular Physics. - : Taylor & Francis. - 0026-8976 .- 1362-3028. ; 61:1, s. 131-141
-
Tidskriftsartikel (refereegranskat)abstract
- The isothermal enthalpy relaxation of glassy 1,2,6-hexanetriol has been measured at six temperatures. The relaxation time and the distribution parameters extracted from fits of the Williams-Watts relaxation function are compared with parameters obtained by other techniques and on other substances. A detailed comparison of the Williams-Watts and the Davidson-Cole relaxation functions is presented.
|
|
| 4. |
- Fransson, Åke, et al.
(författare)
-
Isothermal enthalpy relaxation of glycerol
- 1987
-
Ingår i: International journal of thermophysics. - : Plenum Publishing. - 0195-928X .- 1572-9567. ; 8:3, s. 351-362
-
Tidskriftsartikel (refereegranskat)abstract
- The isothermal enthalpy relaxation of glycerol has been measured at 13 different annealing times at temperatures of 170, 175, 180, and 185 K. The glasses were formed by linear cooling at 0.667 and 0.083 K·s−1 in a differential scanning calorimeter (DSC). The Williams-Watts relaxation function was fitted to data of enthalpy versus time. A strong temperature dependence was found for the relaxation time. The distribution parameter, β, showed an increase from 0.49 at 170 K to 0.65 at 185 K. We also found indications of an enthalpy dependence in β. Comparison with a theory of volume relaxation showed differences between rates of volume and enthalpy relaxation.
|
|
| 5. |
- Nilsson, Ove, et al.
(författare)
-
Thermal properties of silica aerogel
- 1986
-
Ingår i: Aerogels. - Berlin : Springer. - 9783540162568 - 9783642933134 ; , s. 121-126
-
Konferensbidrag (refereegranskat)abstract
- Energy savings have become more and more important because of the increasing cost of energy. Insulation is then a very vital point. An important part when insulating houses are the windows where you have most of the transmission losses. The glass in this study, silica aerogel, has been produced to meet this problem, using it as an insulating spacer in double pane windows.
|
|
