Search Results - (Author, Cooperation:O. Ramirez)

2014-01-28

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Agriculture/history ; *Alleles ; Biological Evolution ; Caves ; European Continental Ancestry Group/*genetics ; Eye Color/genetics ; *Fossils ; Genome, Human/genetics ; Genomics ; History, Ancient ; Humans ; Immunity/*genetics ; Lactose Intolerance/genetics ; Male ; Pigmentation/*genetics ; Polymorphism, Single Nucleotide/genetics ; Principal Component Analysis ; Skeleton ; Skin Pigmentation/genetics ; Spain/ethnology

2018-01-31

The American Society for Microbiology (ASM)

0022-538X

1098-5514

Medicine

1089-7550

AIP Digital Archive

Physics

In this article, we present pyroelectric investigations of electrically poled side-chain polymers containing mesogenic disazobenzene chromophores using a very simple setup. Heating above the glass temperature (about 104°C) usually eliminates the pyroelectric effect of the sample. However, in samples with an indium tin oxide/aluminum electrode design, a self-poling effect is observed. The pyroelectric coefficients of electrically poled samples reach values of up to 0.2 μC/(m2K). From this, we conclude that the strongly anisometric side chains can be reoriented, and that their degree of alignment is about 3%. © 2002 American Institute of Physics.

Electronic Resource

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

The ontogeny of brain creatine kinase (CK) was studied during chick embryo development. The cytosolic activity increased 270% in 10 h from the 2nd to the 3rd days of incubation; this was followed by a plateau phase throughout development and at the end of incubation there appeared to be another increase of cytosolic and mitochondrial CK activities. Therefore, early embryonic chick brain CK is another‘constitutive’enzyme like the early embryonic chick heart CK since creatine has not been enzymatically detected in the embryo until day 4 of incubation. Insulin does not appear to stimulate the early increase of brain CK activity since the hormone is not present in the embryo until day 5 of incubation. It is likely that CK increase is associated with neuronal multiplication at early stages and possibly to neuronal maturation before hatching.

Electronic Resource

1089-7690

AIP Digital Archive

Physics

Chemistry and Pharmacology

In a one-dimensional, two-component excitable chemical model system (the "Brusselator'') we investigate the effects of controlling the flow of reactants at the boundary, on the stability of the thermodynamical branch. The reflectivity of the boundary adjusts the external flux and acts as a control parameter, capable of enhancing or weakening the self-organizing processes leading to the appearance of temporal or spatial patterns. © 1996 American Institute of Physics.

Electronic Resource

0027-5107

Chromium(III) chloride ; Chromium(VI) oxide ; Drosophila ; Genotoxicity ; Mitotic recombination ; Somatic cells

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Medicine

Electronic Resource

0305-0491

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Electronic Resource

1432-0614

Springer Online Journal Archives 1860-2000

Biology

Process Engineering, Biotechnology, Nutrition Technology

Abstract The effect of some culture variables in the production of β-galactosidase from Escherichia coli in Bacillus subtilis was evaluated. The lacZ gene was expressed in B. subtilis using the regulatory region of the subtilisin gene aprE. The host contained also the hpr2 and degU32 mutations, which are known to overexpress the aprE gene. We found that, when this overproducing B. subtilis strain was grown in mineral medium supplemented with glucose (MMG), β-galactosidase production was partially growth-associated, as 40%–60% of the maximum enzyme activity was produced before the onset of the stationary phase. In contrast, when a complex medium was used, β-galactosidase was produced only at low levels during vegetative growth, whereas it accumulated to high levels during early stationary phase. Compared with the results obtained in complex media, a 20% increase in specific β-galactosidase activity in MMG supplemented with 11.6 g/l glucose was obtained. On the 1-l fermenter scale, a threefold increase in volumetric β-galactosidase activity was obtained when the glucose concentration was varied from 11 g/l to 26 g/l. In addition, glucose feeding during the stationary phase resulted in a twofold increase in volumetric enzyme activity as cellular lysis was prevented. Finally, we showed that oxygen uptake and carbon dioxide evolution rates can be used for on-line determination of the onset of stationary phase, glucose depletion and biomass concentration.

Electronic Resource

1432-203X

Key wordsSolanum chrysotrichum ; Cell suspension culture ; Spirostanol saponins ; Antimycotic ; Large-scale culture

Springer Online Journal Archives 1860-2000

Biology

Abstract Cells of two different cell lines: ccvx (cotyledon derived) and ccvz (hypocotyl derived) of Solanum chrysotrichum were cultivated in 10-l airlift bioreactors for the production of the human antimycotic compound SC-1. When using 3 g l–1 dry weight inoculum in a batch culture, higher levels of biomass were achieved with the ccvx cell line (14.6 g l–1) than with ccvz (7.7 g l–1), resulting in 23 and 12 mg g–1 of SC-1 after 17 days in culture for ccvx and ccvz, respectively. The maximum productivity of SC-1 in bioreactors was 0.025 g l–1 day–1 after 9 days in culture. When using a draw-fill mode, the productivity increased by 60% to a value of 0.041 g l–1 day–1, 4 days after 50% of the cell suspension was removed and replaced with fresh medium. This latter bioreactor system is a feasible alternative for the production of the antimycotic metabolite of S. chrysotrichum on a large scale.

Electronic Resource

1432-203X

Solanum chrysotrichum ; Cell suspension culture ; Spirostanol saponins ; Antimycotic ; Large-scale culture

Springer Online Journal Archives 1860-2000

Biology

Abstract Cells of two different cell lines:ccvx (cotyledon derived) andccvz (hypocotyl derived) ofSolanum chrysotrichum were cultivated in 10-1 airlift bioreactors for the production of the human antimycotic compound SC-1. When using 3 g l-1 dry weight inoculum in a batch culture, higher levels of biomass were achieved with theccvx cell line (14.6 g l-1) than withccvz (7.7 g l-1), resulting in 23 and 12 mg g-1 of SC-1 after 17 days in culture forccvx andccvz, respectively. The maximum productivity of SC-1 in bioreactors was 0.025 g l-1 day-1 after 9 days in culture. When using a draw-fill mode, the productivity increased by 60% to a value of 0.041 g l-1 day, 4 days after 50% of the cell suspension was removed and replaced with fresh medium. This latter bioreactor system is a feasible alternative for the production of the antimycotic metabolite ofS. chrysotrichum on a large scale.

Electronic Resource

1573-6784

Springer Online Journal Archives 1860-2000

Process Engineering, Biotechnology, Nutrition Technology

Summary Mouse hybridoma cells were succesfully cultivated for more than 640 hours in the interparticle spaces of a tubular reactor packed with spherical glass beads. The maximum monoclonal antibody (MAb) concentration attained was 110 mg/l and a viable cell density in the order of 1 × 107 cells/ml was achieved. A productivity per reactor void volume of 5.2 mg MAb/hr/l was obtained, which is comparable to the best systems currently in use.

Electronic Resource

1434-4483

Springer Online Journal Archives 1860-2000

Geosciences

Physics

Zusammenfassung Die vorliegende Studie beschäftigt sich mit der Einschätzung der vertikalen Impuls-Flüsse und der Flüsse von sensibler und latenter Wärme über der gesamten Meeresoberfläche. Ein dreidimensionales Gitter mit 32 × 17 Punkten und Daten von 365 Tagen (von 1. 12. 1978 bis 30. 11. 1979) wird benutzt, um sowohl Jahreszeiten als auch Jahresmittelwerte der Oberflächenflüsse zu erhalten. Die globale Klimatologie zeigt die jahreszeitlichen Schwankungen, den kontinentalen Einfluß, die wichtigsten Meeresströmungen und die typischen Effekte der mittleren Breiten (30°–50°) und der Tropen (30°S–30°N). Das Jahresmittel latenter Wärme weist größere Flüsse über subtropischen Regionen (ca. 280 W/m2) als über polaren Regionen (ca. 80 W/m2) auf, während andererseits das Jahresmittel sensibler Wärme über Polarregionen (ca. 100 W/m2) größere Flüsse als über den Tropen (ca. 40 W/m2) aufweist. Zeitreihen-Analysen der täglichen Schätzwerte von Oberflächenflüssen deuten auf mehr Energie bei hohen Frequenzen aufgrund des Oberflächeneffekts hin; in jedem Fall zeigen die Niederfrequenz-Spektren relativ hohe Energie in den 30 – 50-Tage-Perioden, besonders für mittlere Breiten. Die über einen Zeitraum von 30 – 50 Tagen gesammelten Daten der Oberflächenflüsse dargestellt in Zeit-Breiten-Querschnitten für mittlere Breiten zeigen von Juni bis August über der südlichen Hemisphäre bei 55°S eine Ausbreitung der westlichen Wellen mit der WellenzahlK = 2 und einer Phasengeschwindigkeit im Ausmaß von 12° pro Tag.

Summary Vertical fluxes of momentum, sensible and latent heat have been estimated over the surface of the global oceans. A three-dimensional mesh grid 32 longitude points, 17 latitude points and 365 days from December 1, 1978 to November 30, 1979 is used to obtain seasonal and annual mean values of the surface fluxes. The global climatology shows the seasonal variation, the continental influence, the principal ocean currents and the typical middle latitude (30°–50°) and tropical effects (30°S–30°N). The annual mean of latent heat shows greater flux over the subtropical regions (~ 280 W/m2) than in the polar regions (~ 80 W/m2). On the other hand, the annual mean of sensible heat shows greater flux over the polar regions (~ 100 W/m2) than in the tropics (~ 40 W/m2). Time series analyses of the daily estimates of the surface fluxes show greater energy at high frequencies due to the surface effect; however, the low-frequency spectra show relatively high energy at the 30- to 50-day mode, especially for the middle latitude regions. The 30–50 day filtered data for the surface fluxes, presented in time/latitude cross-sections for the middle latitude regions show a westerly wave propagation with wave numberK = 2 and phase speed of the order of 12 degrees/day from June to August over the southern hemisphere at 55°S.

Electronic Resource

0006-3592

Chemistry ; Biochemistry and Biotechnology

Wiley InterScience Backfile Collection 1832-2000

Biology

Process Engineering, Biotechnology, Nutrition Technology

5 Ill.

Electronic Resource

0006-3592

Chemistry ; Biochemistry and Biotechnology

Wiley InterScience Backfile Collection 1832-2000

Biology

Process Engineering, Biotechnology, Nutrition Technology

A mouse-mouse hybridoma was grown in serum-free medium supplemented with bovine milk or colostrum. Bovine colostrum supported growth of the hybridoma whereas bovine milk alone did not support cellular proliferation. For growth in medium supplemented with colostrum, the maximum cell concentration achieved was 1.4 × 106 cells/mL in 2.2% colostrum, which is 44% of that obtained in 9% serum. When cells were grown in media containing milk and low amounts of serum (〈1%) the maximum cell concentration in 2.2% milk with 0.4% serum was 2 × 106 cells/ml, whereas it was only 0.2 × 106 cells/ml and 1.3 × 106 cells/ml in 2.2% milk alone and 0.4% serum alone, respectively. Similar behavior was observed for growth in media containing colostrum and low amounts of serum. The monoclonal antibody production in media containing combinations of serum and milk or colostrum was comparable to that obtained in media with higher serum concentrations. Experiments performed with conditioned media suggest that the rapid decrease in viability, after the maximum cell concentration has been reached, is partially due to the presence of some inhibitory components generated during the cell culture rather than due to depletion of some serum components.

7 Ill.

Electronic Resource