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1.
Francesc Gòdia Carles Casas Bernardo Castellano Carles Solà 《Applied microbiology and biotechnology》1987,26(4):342-346
Summary Data of cell concentration, viability and microscopic observation of cell distribution inside carrageenan immobilized yeast beads are reported. Results were obtained from a continuous packed-bed reactor performing alcoholic fermentation and the main observations made on cell activity are in agreement with the fermentation profiles inside the fermenter. 相似文献
2.
To study the effects of volume overload and renal failure on plasma levels of immunoreactive atrial natriuretic hormone (IR-ANH), we measured levels of this hormone in normal subjects, in patients with advanced chronic renal failure (CRF) with and without clinically evident volume overload, and in patients with end-stage renal disease (ESRD) treated with chronic hemodialysis. The levels were 13 +/- 2 pmol/l in normal volunteers, 77 +/- 24 pmol/l in patients with CRF without volume overload, and 219 +/- 50 pmol/l in patients with CRF and clinically evident volume overload (analysis of variance, p less than 0.001, alpha = 0.05 compared to normals). In patients with ESRD, the levels of IR-ANH were 145 +/- 46 pmol/l before dialysis and decreased to 87 +/- 31 after dialysis (p less than 0.025). No correlation was found between the decrease in IR-ANH levels and the decrease in weight during dialysis. A significant positive correlation was found between the IR-ANH levels and blood urea nitrogen in patients with CRF (r = 0.658, p less than 0.01). Volume overload appears to be the most important stimulatory factor for ANH secretion in renal failure patients but other mechanisms, especially a decrease in metabolic clearance, may also contribute to elevated plasma levels. The increased secretion of ANH in patients with renal failure may be an important adaptive response to volume overload and hypertension. 相似文献
3.
J. Čatský D. K. Velichkov Jana Pospísilová Jarmila Solárová Ingrid Tichá 《Biologia Plantarum》1987,29(5):355-364
The carbon balances of whole, 21-d old French bean plants (Phaseolus vulgaris L.) grown in standard nutrient solution (1K) and its modifications without (OK) or surplus (2K) potassium were calculated
from the daily photosynthetic carbon inputs of individual leaves, and the daily respiratory carbon losses by individual leaves,
stalks and petioles, and roots. Under the three K concentrations, maximum net photosynthetic rates (Pn) were found in the 2nd or in the 3rd trifoliate leaves, maximum respiratory rates (Rd) in the youngest, 4th trifoliate leaves; the Pn/Rd ratio decreased with leaf age. In all leaves of 2K plants, leaf dry masses and thicknesses, Pn, Pn/Pd ratios, and stomatal and intracellular conductances were lower than in OK and IK plants. Daily whole-plant net carbon gain
was highest in IK plants, whereas in OK and 2K plants it was 98.0 and 81.3 % of IK, respectively. Similar values were found
in the parameters of growth analysis, namely in net assimilation rates and relative growth rates.
No differences were found in water potential (Ψ
w
) or water saturation deficit (Wsat) in the OK, 1K and 2K plants sufficiently supplied with water or during wilting and resaturation. The decrease in Ψw to −0.97 MPa was associated with a 19.9 %, 31.4 % and 23.4 % decrease in Pn of OK, 1K and 2K plants, respectively, but no effect on Rd was found. In the three variants, the short-time effect of mild water stress was fully reversible. 相似文献
4.
Caminal G Lafuente J López-Santín J Poch M Solà C 《Biotechnology and bioengineering》1987,29(3):366-369
A recursive estimation scheme, the Extended Kalman Filter (EKF) technique, was applied to study enzymatic deactivation in the enzymatic hydrolysis of pretreated cellulose using a model previously developed by the authors. When no deactivation model was assumed, the results showed no variation with time for all the model parameters except for the maximum rate of cellobiose-to-glucose conversion (r'(m)).The r'(m) variation occurred in two zones with a grace period. A new model of enzymatic hydrolysis of pretreated cellulose deactivation was proposed and validated showing better behavior than the old deactivation model. This approach allows one to study enzyme deactivation without additional experiments and within operational conditions. 相似文献
5.
Mathematical modelization of a packed-bed reactor performance with immobilized yeast for ethanol fermentation 总被引:1,自引:0,他引:1
The performance of a continuous vertical packed-bed reactor with yeast immobilized in carrageenan gel beads is reported. The study focuses on the mathematical modelling of the steady-state fermentor behavior by means of a tanks-in-series model which includes the intrinsic kinetic model and the external mass transfer and internal diffusion-reaction conditions in the beads. 相似文献
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Carbon content of the neritic scyphomedusa Chrysaora fuscescens 总被引:1,自引:0,他引:1
An analysis of the role of scyphomedusae in a planktonic ecosystemrequires that biomass or numerical abundance estimates be convertibleinto standard units for comparison with other components ofthe planktonic community. One species under investigation isthe brown sea nettle, Chrysaora fuscescens, which is very abundantin coastal waters of the west coast of North America (Shenker,1984). For this species, the carbon content of whole immatureanimals and the body components of sexually mature medusae weredetermined. Immature medusae contained a mean carbon content0.202% of the wet weight. The bell, oral arms and gonadal tissueof mature medusae had mean carbon levels 0.156, 0.554 and 0.576%of the wet weight, respectively. When the relative proportionsof these body tissues were calculated, the mean carbon contentof whole mature medusae was determined to be 0.280% of the wetweight. 相似文献
10.