Best Storage Conditions Research Articles

Normal and Late Harvesting of Corn for Silage

Corn silage was harvested in two successive years at the hard dough stage (normal) and seven to eight weeks later after full maturity and additional weathering (late). Dry matter yield was 19 to 27% less when harvested late. Dry matter content of the normal crops at harvest was 26 and 30%; that of late harvested crops was 58 and 63%. Average dry matter recovery rate was slightly lower in the normal silage, 92 vs. 96, and no differences in feeding value were detected when fed in a mixed ration for milking cows. Small reductions in the digestibility of dry matter and acid detergent fiber in late silage were noted in one year (60 vs. 63%), as was a tendency to heat when fed in hot weather. Normal silage contained more acetic, propionic, butyric, and lactic acid than late silage (2.8, 0.2, 0.2, and 7.8 vs. 1.4, 0.1, 0.1, and 3.7%, respectively). The results indicated that production of high quality silage from late harvesting is quite possible under good storage conditions, but the practice would usually be impractical because of high field losses.

The determination of urinary 17-ketosteroids by an improved Zimmermann reaction.

Improvements in the Zimmermann reaction are effected by using methanol as a solvent for the reagents employed in the reaction in place of ethanol or aqueous ethanol. The advantages are as follows. Considerably lower blanks are obtained; extraneous chromogens are negligible at the wavelength of measurement, so that no correction procedure or extraction process is required; high concentrations of potassium hydroxide may be used at an elevated temperature leading to good sensitivity and a considerably shortened reaction time; and finally, the potassium hydroxide is stable for long periods under good storage conditions. A steroid with keto (oxo) groups at positions 3, 11, and 20, but not at 17, failed to give any coloured product.

Easy Control Procedures for Radio-Iodinated Human Serum Albumin and their Practical Importance

Summary1. Two shipments of radio-iodinated human serum albumin (RISA), produced by different commercial laboratories, were analysed by ascending and circular chromatography, electrophoresis, autoradiography and radioactive scanning.2. Both shipments were subdivided into three samples and each kept under slightly different conditions, in order to study the best conditions for storage of the product.3. Results obtained showed progressive albumin denaturation in both shipments, with the formation of radioactive degradation products and radioactive iodide. This process of radiolysis was less intense in the samples maintained permanently in the refrigerator and handled as little as possible.4. The extent of alteration induced was smaller when the protein concentration was around 5 mg per ml and the initial radioactivity less than 0.8 mCper ml.5. The results obtained show the need for a frequent control of the albumin, not only in relation to the iodide liberated, but also with respect to degradation of the albumin by radiolysis.6. Circular chromatography followed by autoradiography is the simplest method of control which can be easily performed in any clinical laboratory.

Preserving the sterility of surgical dressings wrapped in paper and other materials.

Materials for wrapping surgical dressings were studied by a method which measured the recontamination rate in packs stored for periods of up to several weeks. Of the materials tested a thick crêpe paper was better than calico and balloon cloth fabrics. Dressings wrapped in paper were not significantly contaminated after storage in dusty places for periods of up to three weeks. For added protection during handling and for convenience in transport and storage, paper packs may be sterilized and kept in paper-lined cartons. The shelf life in good storage conditions would be many weeks at least.