Levels of DNA, cholesterol, and phospholipids of mouse caudal epididymal and vas deferens sperm that were processed through simple washing and Percoll gradient centrifugation were measured. The DNA and cholesterol contents of washed sperm and Percoll gradient centrifuged (PGC) sperm (DNA = 3.6 +/- 0.3 pg/sperm and 3.4 +/- 0.3 pg/sperm, respectively; cholesterol = 0.219 +/- 0.057 nmole/microgram DNA and 0.224 +/- 0.030 nmole/microgram DNA, respectively, for washed and PGC sperm) were not significantly different from each other; however, the phospholipid level of PGC sperm was only one half of that of washed sperm (0.315 +/- 0.071 nmole/microgram DNA versus 0.720 +/- 0.075 nmole/microgram DNA, respectively). The presence of 0.3% bovine serum albumin (BSA) in the culture medium used in sperm washing did not change the cholesterol and phospholipid contents of washed sperm. Similarly, the cholesterol and phospholipid levels of washed sperm and PGC sperm that were further incubated in BSA-containing medium for 30 min remained the same. Interestingly, substantial amounts of lipids, as determined by the cholesterol and phospholipid levels, were released into the supernatants of the sperm washes, and sperm needed to be washed at least twice to ensure their stable levels of cholesterol and phospholipids. The lipid mixture in the first sperm wash supernatant was shown to have inhibitory effects on PGC sperm motility.

Levels of DNA, cholesterol, and phospholipids of mouse caudal epididymal and vas deferens sperm that were processed through simple washing and Percoll gradient centrifugation were measured. The DNA and cholesterol contents of washed sperm and Percoll gradient centrifuged (PGC) sperm (DNA = 3.6 ± 0.3 pg/sperm and 3.4 ± 0.3 pg/sperm, respectively; cholesterol = 0.219 ± 0.057 nmole/μg DNA and 0.224 ± 0.030 nmole/μg DNA, respectively, for washed and PGC sperm) were not significantly different from each other; however, the phospholipid level of PGC sperm was only one half of that of washed sperm (0.315 ± 0.071 nmole/μg DNA versus 0.720 ± 0.075 nmole/μg DNA, respectively). The presence of 0.3% bovine serum albumin (BSA) in the culture medium used in sperm washing did not change the cholesterol and phospholipid contents of washed sperm. Similarly, the cholesterol and phospholipid levels of washed sperm and PGC sperm that were further incubated in BSA‐containing medium for 30 min remained the same. Interestingly, substantial amounts of lipids, as determined by the cholesterol and phospholipid levels, were released into the supernatants of the sperm washes, and sperm needed to be washed at least twice to ensure their stable levels of cholesterol and phospholipids. The lipid mixture in the first sperm wash supernatant was shown to have inhibitory effects on PGC sperm motility. © 1996 Wiley‐Liss, Inc.

As quality aggregate resources are exhausting with massive construction development, inferior aggregate resources somehow are the only picks on the jobsite. The negative impact of inferior aggregates on the workability of fresh concrete is becoming pronounced worrisome on the constructability of concrete structures due mainly to their poor gradation. Therefore, intelligent approach must be found to make fresh concrete workable and consistent while using inferior aggregates. In this study, uniform aggregate gradation curve, Aggregate Coarseness Factor (ACF) and Workability Factor (WF) were used to control the gradation of blended aggregates for achieving desirable workability of fresh concrete. Experimental study and engineering practices indicate that uniform aggregate gradation curve cooperating with ACF and WF are reliable tools to control workability of fresh concrete and obtain quality concrete while only poor aggregates available.