The Carbon Monoxide-binding Pigment of Liver Microsomes I. EVIDENCE FOR ITS HEMOPROTEIN NATURE

A simple technique for the determination in vitro of the dry- or organic-matter digestibility of small (0·5 g) samples of dried forages is described. It involves incubation first with rumen liquor and then with acid pepsin. Using 146 samples of grass, clover and lucerne of known in vivo digestibility (Y), the regression equation Y= 0·99 X– 1·01 (S.E. ± 2·31) has been calculated, where X=in vitro dry-matter digestibility. This technique has been used for the study of the digestibilities of plant breeder's material, of the leaf and stem fractions of herbage and of herbage consumed by animals.

A two-stage technique for the in vitro digestion of forage crops

For centuries knowledge meant proven knowledge — proven either by the power of the intellect or by the evidence of the senses. Wisdom and intellectual integrity demanded that one must desist from unproven utterances and minimize, even in thought, the gap between speculation and established knowledge. The proving power of the intellect or the senses was questioned by the sceptics more than two thousand years ago; but they were browbeaten into confusion by the glory of Newtonian physics. Einstein’s results again turned the tables and now very few philosophers or scientists still think that scientific knowledge is, or can be, proven knowledge. But few realize that with this the whole classical structure of intellectual values falls in ruins and has to be replaced: one cannot simply water down the ideal of proven truth - as some logical empiricists do — to the ideal of’probable truth’1 or — as some sociologists of knowledge do — to ‘truth by [changing] consensus’.2

Falsification and the Methodology of Scientific Research Programmes

The preparation and chemical characteristics of hemoglobin-free ghosts of human erythrocytes

Publisher Summary This chapter discusses the assay of catalases and peroxidases are: (1) catalase assay by disappearance of peroxide; (2) method for crude cell extracts; (3) direct spectrophotometric assay of catalase and peroxidase in cells and tissues; and (4) peroxidase assay by spectrophotometric measurements of the disappearance of hydrogen donor or the appearance of their colored oxidation products. Two methods are described for the catalase assay by disappearance of peroxide are: ultraviolet spectrophotometry and permanganate titration. Ultraviolet spectrophotometryis a method devised, on the basis of the absorption curves for peroxide solutions, for determining the activity of catalase by direct measurements of the decrease of light absorption in the region 230 to 250 mμ caused by the decomposition of hydrogen peroxide by catalase. In the case of method for crude cell extracts, oxygen evolution caused by the decomposition of hydrogen peroxide is measured with the conventional manometric technique. Peroxidase assay by spectrophotometric measurements of the disappearance of hydrogen donor or the appearance of their colored oxidation products includes the guaiacol test and the pyrogallol test.

The assay of catalases and peroxidases.

/pdf/the-crystal-structure-of-nam2iv-po4-3-meiv-ge-ti-zr-59kkoy744f.pdf

The Crystal Structure of NaM2IV(PO4)3; MeIV = Ge, Ti, Zr.

/pdf/the-molar-light-absorption-of-pyridine-ferroprotoporphrin-3htutqlebe.pdf

The Molar Light Absorption of Pyridine Ferroprotoporphrin (Pyridine Haemochromogen).

/pdf/a-flow-micro-reaction-calorimeter-4yosi33gih.pdf

A Flow Micro Reaction Calorimeter.

/pdf/crystalline-rhodanese-i-purification-and-physicochemical-lkp0tvvc3f.pdf

Crystalline Rhodanese. I. Purification and Physicochemical Examination.

/pdf/studies-on-the-hexagonal-tungsten-bronzes-of-potassium-43xozu1v0k.pdf

Artturi I. Virtanen

Papers

The Crystal Structure of NaM2IV(PO4)3; MeIV = Ge, Ti, Zr.

The Molar Light Absorption of Pyridine Ferroprotoporphrin (Pyridine Haemochromogen).

A Flow Micro Reaction Calorimeter.

Crystalline Rhodanese. I. Purification and Physicochemical Examination.

Studies on the Hexagonal Tungsten Bronzes of Potassium, Rubidium, and Cesium.