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The desorption isotherms of apples of the Granny Smith variety, treated with 0.5% citric acid aqueous solution, were determined using the gravimetric static method. Experiments at three temperature levels: 20°C, 40°C and 60°C and ten water activity levels from 0.112 to 0.856 were carried out. Along with five well known models - modified Chung-Pfost, modified Halsey, modified Oswin, modified Henderson and GAB (Guggenheim-Anderson-de Boer), a new fraction-linear model has been applied to fit the data and to calculate the isosteric heat of desorption determination. 相似文献
33.
Fatty acids are a major source of fuel for energy production by myocytes. Lipoprotein lipase (LPL) and very low density lipoprotein (VLDL) receptor are abundantly expressed by the heart and skeletal muscles. LPL and possibly VLDL receptor represent the primary route of access to fatty acids contained in circulating triglyceride-rich lipoproteins. Physical exercise and thyroid hormone, which promote energy consumption, upregulate LPL expression in skeletal muscles. This study tested the hypothesis that increased cardiac workload might modulate myocardial LPL and/or VLDL receptor expressions. Accordingly, cardiac tissue LPL activity, LPL and VLDL receptor proteins and mRNA abundance were studied in Sprague-Dawley rats 4 weeks after induction of severe thoracic aorta constriction or sham operation. Elevation of afterload with thoracic aortic constriction led to a significant cardiomegaly and a marked upregulation of cardiac LPL activity, LPL mRNA and LPL protein abundance, but did not modify VLDL receptor mRNA or protein abundance. Thus, increased cardiac workload in this model results in upregulation of myocardial LPL expression which can enhance fatty acid availability to accommodate the heart's increased energy requirement. 相似文献
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H Kino H Inaba N Van De L Van Chau DT Son HT Hao ND Toan LD Cong M Sano 《Canadian Metallurgical Quarterly》1998,29(2):250-254
We present the spatial structure of binase, a small extracellular ribonuclease, derived from 1H-NMR* data in aqueous solution. The total of 20 structures were obtained via torsion angle dynamics using DYANA program with experimental NOE and hydrogen bond distance constraints and phi and chi1 dihedral angle constraints. The final structures were energy minimised with ECEPP/2 potential in FANTOM program. Binase consists of three alpha-helices in N-terminal part (residues 6-16, 26-32 and 41-44), five-stranded antiparallel beta-sheet in C-terminal part (residues 51-55, 70-75, 86-90, 94-99 and 104-108) and two-stranded parallel beta-sheet (residues 22-24 and 49-51). Three loops (residues 36-39, 56-67 and 76-83), which play significant role in biological functioning of binase, are flexible in solution. The differences between binase and barnase spatial structures in solution explain the differences in thermostability of binase, barnase and their hybrids. 相似文献
36.
N. D. Menkov 《Molecular nutrition & food research》1997,41(6):349-351
Temperature influence on the equilibrium moisture content in case of constant relative air humidity. The possibility of determining the equilibrium moisture content of materials at different hygrothermal conditions by a smaller number of experiments is investigated. It has been established for a large number of foodstuffs that the equilibrium moisture content in case of constant relative air humidity depends linearly on the temperature. Two equilibrium isotherms are sufficient to determine the equilibrium moisture content of these foodstuffs at different temperatures and relative air humidities. 相似文献
37.
QY He AB Mason RC Woodworth BM Tam RT MacGillivray JK Grady ND Chasteen 《Canadian Metallurgical Quarterly》1997,36(48):14853-14860
Human serum transferrin N-lobe (hTF/2N) has four iron-binding ligands, including one histidine, one aspartate, and two tyrosines. The present report elucidates the inequivalence of the two tyrosine ligands (Tyr 95 and Tyr 188) on the metal-binding properties of hTF/2N by means of site-directed mutagenesis, metal release kinetics, and absorption and electron paramagnetic resonance (EPR) spectroscopies. When the liganding tyrosines were mutated individually to phenylalanine, the resulting mutant Y95F showed a weak binding affinity for iron and no affinity for copper, whereas, mutant Y188F completely lost the ability to bind iron but formed a stable complex with copper. Since other studies have demonstrated that mutations of the other two ligands, histidine and aspartate, did not completely abolish iron binding, the present findings suggest that the tyrosine ligand at position 188 is essential for binding of iron to occur. Replacement of Tyr 188 with phenylalanine created a favorable chemical environment for copper coordination but a fatal situation for iron binding. The positions of the two liganding tyrosines in the metal-binding cleft suggest a reason for the inequivalence. 相似文献
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II Degtiareva EV Lodianaia ND Opanasiuk OL Palladina 《Canadian Metallurgical Quarterly》1995,(7-8):84-87
A peroral sugar-reducing preparation gliquidone (glurenorm) was tried in treatment of 66 patients with digestive diseases (peptic ulcer, chronic pancreatitis, cirrhosis of the liver), presenting with diabetes mellitus. The results of the studies made showed glurenorm to be a highly effective preparation in term of both its sugar-reducing effect and its capability to improve energy processes in gastric and duodenal mucosa, pancreacytes, hepatocytes, besides which, it appear to dispel metabolic disturbances and stimulate reparative processes in body organs, improves protein-synthetic processes in the liver, pancreas, mucosa of the gastroduodenal region. 相似文献
40.