A Study of Laboratory Teaching

A committee was appointed in 1930 at Iowa State College to make a study of methods of laboratory instruction. This study has brought out some rather interesting information which it is thought may be of general interest. Some of the more interesting problems considered by the committee are; length of laboratory period, demonstration laboratory, size of section, correlation between laboratory and recitation, organization of course, equipment and qualifications of a good laboratory instructor

2-aminophenols containing electron-withdrawing groups from N-aryl hydroxylamines

Reaction of substituted N-aryl hydroxylamines with methanesulfonyl chloride, p-toluenesulfonyl chloride, or trifluoromethanesulfonic anhydride under basic conditions leads to the rearranged 2-aminophenols (45-94%). The overall reaction sequence can be performed using polymer-supported sulfonyl chloride resin allowing for the effective conversion of N-aryl hydroxylamines to the 2-aminophenols without the need for chromatography

Ultra Violet Absorption Spectra of Carotene and Vitamin A

Using a sensitive photo electric spectrophotometer, carotene derived from carrots and dissolved in an oil, has been found to exhibit an absorption band in the region 325-330 Mμ. An absorption band in this region has been shown by Morton & Heilbron to be characteristic of vitamin A in fats derived from animal sources. The appearance of this band in carotene from a vegetable source, establishes an even closer relationship between these two growth-promoting factors

Absorption Spectra Characteristic of Vitamin A in Animal and Vegetable Oils

A continuation of our previous work on the ultra-violet absorption spectra of substances showing vitamin A activity, tends to further substantiate the evidence that the absorption band in the regions 325-330 m.μ., which Morton and Heilbron have shown to be characteristic of vitamin A in animal fats, also characterizes vegetable compounds containing the growth promoting factor

Studies on the Effect of Ultra-Violet Rays upon Yeast Metabolism - I. The Effect of Ultra Violet Light upon the Medium

74. Studies on the effect Exposure of the medium (composed of optimum concentrations of salts and sugar) to ultra-violet light renders it less effective for the growth of yeast. The development of the toxicity increases with duration and intensity of irradiation. An exposure of seven hours through quartz at about l5 cm from a quartz mercury vapor lamp affects the medium in such a way that yeast will show practically no growth in the medium. The work is being continued in order to obtain quantitative results and to explain the phenomenon

The Growth of Chickens as Effected by the Sunlight Transmitted through Glass Substitutes

Three weeks\u27 old chicks which had been deprived of direct sunlight and fed on a rachitic diet, were placed behind common glass and glass substitutes for four weeks. Those behind glass made an average gain of 180 per cent, while the groups behind the substitutes made gains of 300 per cent and 250 per cent. All outward appearances of rickets had disappeared among those behind the glass substitutes, while the disease was in evidence in the case of those behind glass

Absorption Spectrum of Vitamin A Concentrates

This is a continuation of the work previously reported by Woodrow and Cunningham (Phys. Rev., vol. 35, p. 125, Jan. 1930) on the absorption spectrum of several common sources of vitamin A. Through the kindness of Dr. Morton of the University of Liverpool, it has been possible to investigate the absorption spectra of much more concentrated sources of vitamin A. Slight changes which have been made in the arrangement of the photoelectric spectrophotometer have given more dependable results, partly because they have greatly reduced the destruction of the vitamin A by the ultra-violet light used in taking the measurements. Prominent bands have been found at 310 and 328 mµ. with minor bands at 323 and 340 mμ. The 328 mμ band was much stronger than the same band with weaker sources of vitamin A

Illinoian and Late Wisconsin Tills in Eastern New England: a Transect from Northeastern Massachusetts to West-Central Maine

Guidebook for field trips in southern and west-central Maine, October 13, 14 and 15, 1989: New England Intercollegiate Geological Conference 81st annual meeting: Trip A-

Prevention of recurrent sudden cardiac arrest: role of provocative electropharmacologic testing

This study evaluates the usefulness of serial provocative electropharmacologic testing for predicting the efficacy of prophylactic antiarrhythmic treatment regimens in patients resuscitated from sudden cardiac arrest in the absence of acute myocardial infarction. Testing was carried out in 34 consecutive patients (28 men and 6 women) who required cardiopulmonary resuscitation and direct current countershock for treatment of primary ventricular fibrillation (28 patients), ventricular tachycardia (5 patients) or excessively rapid heart rate during atrial fibrillation with preexcitation (1 patient).In 8 (24%) of the 34 patients, drug testing either was not feasible because of absence of inducible arrhythmia or was incomplete because of patient withdrawal from study; and 3 of these 8 patients had recurrent sudden cardiac arrest within 10 to 19 months. In an additional five patients, treatment regimens failed to prevent initiation of sustained ventricular tachyarrhythmias in the catheterization laboratory, and two of these five patients had cardiac arrest recurrences within 2 weeks to 25 months of follow-up. In the remaining 21 (62%) of the 34 patients, including 3 patients with preexcitation syndrome, a drug regimen or surgical treatment, or both, was found that prevented inducible life-threatening tachyarrhythmias in the laboratory. Subsequently, only 1 (5%) of these 21 patients died suddenly within a 7 to 38 month (mean ± standard deviation, 18 ± 8.3) follow-up period. Thus, provocative electropharmacologic testing appears to be useful in predicting response to therapy in survivors of sudden cardiac arrest