scholarly journals Isolation of Dimethyl Diselenide and Other Volatile Selenium Compounds from Astragalus Racemosus (Pursh.)

1968 ◽  
Vol 21 (1) ◽  
pp. 13 ◽  
Author(s):  
Christine S Evans ◽  
CJ Asher ◽  
CM Johnson
Keyword(s):  
Diethyl Ether ◽  
Activated Charcoal ◽  
Solubility In Water ◽  
Selenium Compounds ◽  
Oven Drying ◽  
Dimethyl Diselenide

Volatile selenium compounds from intact Astragalus racemosus plants and from oven-drying tops or roots of the same species were collected on activated charcoal and fractionated according to solubility in water or diethyl ether.

scholarly journals Expression of the ubiE Gene of Geobacillus stearothermophilus V in Escherichia coli K-12 Mediates the Evolution of Selenium Compounds into the Headspace of Selenite- and Selenate-Amended Cultures

2006 ◽  
Vol 72 (1) ◽  
pp. 963-967 ◽  
Author(s):  
J. W. Swearingen ◽  
D. E. Fuentes ◽  
M. A. Araya ◽  
M. F. Plishker ◽  
C. P. Saavedra ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Geobacillus Stearothermophilus ◽  
Selenium Compounds ◽  
E Coli ◽  
Gene Deficiency ◽  
Dimethyl Selenide ◽  
K 12 ◽  
Cloned Gene ◽  
Dimethyl Diselenide

ABSTRACT The ubiE gene of Geobacillus stearothermophilus V, with its own promoter, was cloned and introduced into Escherichia coli. The cloned gene complemented the ubiE gene deficiency of E. coli AN70. In addition, the expression of this gene in E. coli JM109 resulted in the evolution of volatile selenium compounds when these cells were grown in selenite- or selenate-amended media. These compounds were dimethyl selenide and dimethyl diselenide.

scholarly journals Collection and Partial Characterization of Volatile Selenium Compounds from Medicago Sativa L.

1967 ◽  
Vol 20 (4) ◽  
pp. 737 ◽  
Author(s):  
CJ Asher CS Evans ◽  
CM Johnson
Keyword(s):  
Medicago Sativa ◽  
Activated Charcoal ◽  
Partial Characterization ◽  
Culture Solution ◽  
Selenium Compounds ◽  
Medicago Sativa L ◽  
Total Selenium

Tops and roots of Medicago 8ativa plants raised in culture solution to which 75Se�labelled selenite or selenate had been added were shown to release 0�5-3�0% of their total selenium in volatile form when dried at 70�C for 48 hr. The volatile selenium compounds were collected on activated charcoal.

THE FLOW OF GASES AND VAPORS THROUGH ADSORBING POROUS MEDIA

1948 ◽  
Vol 26b (1) ◽  
pp. 38-53 ◽  
Author(s):  
R. H. Tomlinson ◽  
E. A. Flood
Keyword(s):  
Porous Media ◽  
Diethyl Ether ◽  
Activated Charcoal ◽  
Experimental Methods ◽  
Ethyl Chloride ◽  
Mathematical Form ◽  
Square Root ◽  
Flow Rates ◽  
Gaseous Flow ◽  
Pass Through

The flow rates of gases and vapors through highly activated charcoal rods have been measured. The results obtained indicate that a new phenomenon has been discovered. While the flow rates of gases that are not highly adsorbed can be satisfactorily correlated by the Adzumi equation and other equations of similar mathematical form, it has been found that the strongly adsorbed vapors of diethyl ether and ethyl chloride pass through the charcoal rods at rates considerably m excess of those required by known equations. To explain the results it appears necessary to resort to mechanisms quite outside of those usually considered in the application of kinetic theory to problems associated with passage of gas through porous diaphragms. The simplest and most direct of such mechanisms involves mobility of the adsorbed material. It is particularly striking that the flow rate of diethyl ether through activated charcoal rods has been found to be greater than that of helium in pressure regions where relative rates of flow of gases through non-adsorbing porous diaphragms are dominated by inverse square root molecular weight ratios. The measurement of gaseous flow rates through porous media are rendered the more difficult where appreciable adsorption occurs. The experimental methods are described in detail, sources of error are discussed, and results presented for the gases helium, hydrogen, nitrogen, carbon dioxide, diethyl ether, and ethyl chloride.

Effects of Drying Methods on the Biochemical Composition and Organoleptic Properties of Two Freshwater Fish Species (Mormyrus rume and Labeo coubie) of Cross River Obubra, Nigeria

2019 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Moisture Content ◽  
Fish Species ◽  
Nutrition Status ◽  
Drying Methods ◽  
Organoleptic Properties ◽  
Nutrient Quality ◽  
Oven Drying ◽  
Fish Samples ◽  
Fish And Fishery Products ◽  
Mormyrus Rume

Consumers all over the world are increasingly becoming aware of the health and nutrition status of fish and fishery products. There have develop some preference for fish species and even their processing methods. This study aims to investigate the effects of two drying methods (smoking and oven drying) on the biochemical components and organoleptic properties of two less preferred food fishes abundant in the study area. The fish samples Mormyrus rume and Labeo coubie were purchased from fresh landings of fishermen at Ahaha beach. The biochemical assay of the moisture, protein, fat, carbohydrate, ash, calcium (Ca), magnesium (Mg), phosphorus (P), iron (Fe), sodium (Na) and potassium (K) were conducted in the labouratory using standard methods. The proximate composition of raw M. rume was determined as moisture 70.38%, protein 17.43%, carbohydrate 1.13%, fat 5.93% and ash 2.77% while oven dried were 18.78, 63.85, 3.37, 8.73 and 7.58% respectively. All the proximate parameters and gross energy level investigated were higher (p < 0.05) in M. rume except the moisture content of dried samples of L. coubie. The mineral content were in the order Ca < Mg < Fe < Na < P and < K in both species and were higher in M. rume except Na. The drying methods showed increase in the proximate and mineral compositions in the order raw < smoking and < oven drying except moisture content that decreased respectively is both species. Organoleptic properties revealed that dried samples (smoked and oven) were not significantly different (p < 0.05) in taste, flavour, texture and overall acceptance, however while oven dried had better colour (4.33), smoked dried taste (4.63) better. The drying methods shows concentration of the required nutrients in human diets and were also found to be most palatable by the panellist. To improve fish nutrient quality smoke and oven drying should be encourage.

RADIOIMMUNOASSAY OF OESTRONE AND OESTRADIOL IN THE PERIPHERAL PLASMA OF THE DOMESTIC FOWL IN VARIOUS PHYSIOLOGICAL STATES AND OF HYPOPHYSECTOMIZED AND OVARIECTOMIZED FOWLS

1974 ◽  
Vol 75 (1) ◽  
pp. 133-140 ◽  
Author(s):  
B. E. Senior
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Diethyl Ether ◽  
Bovine Serum ◽  
Domestic Fowl ◽  
Laying Hens ◽  
Peripheral Plasma ◽  
The Mean ◽  
Precision And Accuracy ◽  
Chicken Ovary

ABSTRACT A radioimmunoassay was developed to measure the levels of oestrone and oestradiol in 0.5–1.0 ml of domestic fowl peripheral plasma. The oestrogens were extracted with diethyl ether, chromatographed on columns of Sephadex LH-20 and assayed with an antiserum prepared against oestradiol-17β-succinyl-bovine serum albumin using a 17 h incubation at 4°C. The specificity, sensitivity, precision and accuracy of the assays were satisfactory. Oestrogen concentrations were determined in the plasma of birds in various reproductive states. In laying hens the ranges of oestrone and oestradiol were 12–190 pg/ml and 29–327 pg/ml respectively. Levels in immature birds, in adult cockerels and in an ovariectomized hen were barely detectable. The mean concentrations of oestrone and oestradiol in the plasma of four non-laying hens (55 pg/ml and 72 pg/ml respectively) and one partially ovariectomized hen (71 pg/ml and 134 pg/ml respectively) were well within the range for laying hens. It is evident that the large, yolk-filled follicles are not the only source of oestrogens in the chicken ovary.

Theoretical Exploration of 2,2’-Bipyridines as Electro-Active Compounds in Flow Batteries

2019 ◽  
Author(s):  
Mariano Sánchez-Castellanos ◽  
Martha M. Flores-Leonar ◽  
Zaahel Mata-Pinzón ◽  
Humberto G. Laguna ◽  
Karl García-Ruiz ◽  
...  
Keyword(s):  
Redox Potential ◽  
Active Material ◽  
Chemical Properties ◽  
Small Subset ◽  
Solubility In Water ◽  
Protonation Reaction ◽  
Redox Active ◽  
Physico Chemical ◽  
Pka Value ◽  
Flow Batteries

Compounds from the 2,2’-bipyridine molecular family were investigated for use as redox-active materials in organic flow batteries. For 156 2,2’-bipyridine derivatives reported in the academic literature, we calculated the redox potential, the pKa for the first protonation reaction, and the solubility in aqueous solutions. Using experimental data on a small subset of derivatives, we were able to calibrate our calculations. We find that functionalization with electron-withdrawing groups leads to an increase of the redox potential and to an increase of the molecular acidity (as expressed in a reduction of the pKa value for the first protonation step). Furthermore, calculations of solubility in water indicate that some of the studied derivatives have adequate solubility for flow battery applications. Based on an analysis of the physico-chemical properties of the 156 studied compounds, we down-select five molecules with carbonyl- and nitro-based functional groups, whose parameters are especially promising for potential application as negative redox-active material inorganic flow batteries.

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