Freeform Bioprinting of Liver Encapsulated in Alginate Hydrogels Tissue Constructs for Pharmacokinetic Study

An in vitro model that can be realistically and inexpensively used to predict human response to various drug administration and toxic chemical exposure is needed. By fabricating a microscale 3D physiological tissue construct consisting of an array of channels and tissue-embedded chambers, one can selectively develop various biomimicking mammalian tissues for a number of pharmaceutical applications, for example, experimental pharmaceutical screening for drug efficacy and toxicity along with apprehending the disposition and metabolic profile of a candidate drug. This paper addresses issues relating to the development and implementation of a bioprinting process for freeform fabrication of a 3D cell-encapsulated hydrogel-based tissue construct, the direct integration onto a microfluidic device for pharmacokinetic study, and the underlying engineering science for the fabrication of a 3D microscale tissue chamber as well as its application in pharmacokinetic study. To this end, a prototype 3D microfluidic tissue chamber embedded with liver cells encapsulated within a hydrogel matrix construct is bioprinted as a physiological in vitro model for pharmacokinetic study. The developed fabrication processes are further validated and parameters optimized by assessing cell viability and liver cell phenotype, in which metabolic and synthetic liver functions are quantitated.Mechanical Engineerin

Soybean and alfalfa hays for wintering pregnant ewes

Since the soybean acreage has increased in Iowa and the Corn Belt, the determination of the economic feeding value of this plant deserves attention. Alfalfa and clover have long been considered good legume hays for sheep. Because of the increase in soybean production, which involves a greater volume of soybean hay, the question naturally arises as to how this legume hay compares in feeding value with clover and alfalfa. With this question in mind four lots of pregnant ewes were experimentally fed on soybean and alfalfa hays and certain combinations of these two hays. The results secured are reported herein

Preparation of corn for yearling brood sows

Ear corn and shelled corn proved more efficient than ground ear corn or corn meal for wintering brood sows. This was the result obtained where four groups of 10 sows each received salt (self-fed), and three-fifths of a pound per head daily of a mixture of linseed oilmeal, tankage and wheat middlings, in addition to one of the following: ear corn, shelled corn, corn and cob meal, or ground corn. The differences in gains from the various kinds of corn preparation were not great. Hence, the objection to grinding the corn lies in the cost. Ground shelled corn proved especially costly

Dried buttermilk for growing and fattening pigs

The objects of this experiment were to determine the comparative value and efficiency of meat meal tankage, dried buttermilk and various combinations of these feeds on health, gains, feed requirements, water consumption, time required to reach 225 pounds average weight and other factors, when these protein feeds were self-fed along with shelled corn to growing and fattening pigs in dry lots. The pigs used in this test were very uniform in age, weight and breeding. They were all sired by the same purebred Hampshire boar and were out of either related purebred or very high grade Hampshire sows. The pigs were selected from four litters

Roughages for fattening two-year-old steers

The relative values of different roughages in the winter fattening of two-year-old steers when shelled corn, full-fed, cottonseed meal and salt are allowed, as well as the advisability of limiting the grain fed in a corn silage-alfalfa hay-salt ration are the themes of the experiment covered in this bulletin. How does corn fodder compare in feeding value with corn silage? What are the comparative feeding values of red clover and alfalfa hays? Will timothy and oat straw supply the steers\u27 needs economically when this roughage is balanced with a liberal allowance of cottonseed meal fed with the corn grain and salt? How does mixed timothy-clover hay rank alongside the pure red clover? Can one finish two-year-old. cattle with profit by using corn silage, alfalfa hay and salt without extra grain? These are some of the questions this research throws light upon

Corn Silage for Sows

Experiments with more than 2,000 pigs farrowed at Iowa State College show that corn silage- properly supplemented- makes an excellent and low-cost base ration for sows during pre-gestation and gestation

The salt consumption of sheep: Fattening lambs

1. Common salt (sodium chloride) is one of the essential nutrients in the rations of sheep and lambs, and the proper provision of it makes for a more profitable and satisfactory sheep husbandry. 2. Free-choice salt feeding with our present knowledge appears to be the most satisfactory method of allowance under Corn-belt conditions to secure near-optimum nutritional results. 3. When salt is arbitrarily allowed, mixed with the feeds, experimental results indicate that with our present understanding of the factors controlling salt needs, it is very difficult to approximate the correct quantitative allowance. 4. Researches with wintering ewes indicate that salting the feed may be easily overdone, or underdone. An absence of salt from the feeds allowed ewes resulted in lesser gains, less efficient use of feeds, an impaired lamb crop and a decreased wool yield. The ewes not fed salt developed a marked craving for it. 5. The records kept on 1,306 winter-fed lambs show an average daily salt consumption of 0.011 pound per lamb, the range by lots being from 0.001 to 0.019 pound. It is estimated that lambs fed at Ames secure about one-half of their total sodium (pure common salt contains 39.34 percent of the mineral sodium) and three-fourths of their chlorine (salt contains 60.66 percent of chlorine) from the salt box (salt self-fed). Ames campus water supplies but very little of the total salt constituents, but the feed provides practically all the sodium and chlorine not supplied in the salt box. 6. The character and composition of the rations fed affect in large measure the salt consumption and r equirements of fattening lambs. Feeding beet molasses markedly decreased salt consumption, whereas alfalfa hay had the opposite effect. 7. Fattening lambs consume much more salt per unit weight than steers fed under similar conditions, and whereas the daily salt consumption of lambs increases during the feeding period, that of the steers decreases. Lambs in the finishing lots consume more roughage in proportion to concentrates than do steers; this ratio of roughage to concentrates is the more marked as the period of feeding progresses. The greater the proportion of roughage, the larger apparently is the salt consumption. 8. The salt required for a hundred pounds gain on 1,306 fattening lambs averaged 3.78 pounds, the range being from 0.21 to 11.18 pounds. A typical representative of an average lamb, gaining 30 pounds in our experiments, would therefore require a little over one and a tenth pounds of salt during the winter feeding period. 9. The observations and data as available and interpreted indicate that the free-choice feeding of salt of high grade, block or flake, is good practice in the fattening of lambs

Soybean hay for fattening lambs

The use of soybeans in the Corn Belt has increased considerably in recent years. The ground seed and oilmeal prepared from it, have been quite extensively used for supplemental feeding. Soybeans have likewise been successfully planted along with corn, either for sheeping-down, hogging-down, or silage production purposes. The field of usefulness for soybeans is enlarging to the economic advantage of Iowa farming enterprises. The practical possibilities of growing soybeans for hay are worthy of attention; it was with the idea of determining the relative value of soybean hay, either whole or ground, as compared to clover hay in the ration of fattening lambs, that the experiment reported herein was planned and conducted

Corn of different degrees of hardness for pigs

There were significant differences in the hardness of the varieties of the dent corns fed in these experiments. Hardness of the corn was determined by a machine designed to find out the crushing resistance of the kernels. In the second and third trials, when three tests were made to determine actual crushing resistance, the means ranged from 24.16 pounds on the Special Reid Yellow Dent or soft corn to 41.46 pounds on the Krug. Average for these two trials showed that it required 27.8 pounds to crush the soft type, 30.3 pounds for the medium, Reid Yellow Dent, and 37.1 pounds to crush the hard type, Krug. The hard type corn was 25 percent harder than the soft type corn and 18 percent harder than the medium