• Asian-Australasian Journal of Animal Sciences
• /
• v.6 no.1
• /
• pp.127-132
• /
• 1993

Ten-week-old White Leghorn immature males and females were exposed to four lighting regimens: a constant light (12L : 12D); repeated up and slow down (13 min. up and 1 min. down per day for 13 consecutive days, and repeated on two-week cycle) lighting; repeated slow up and down (1 min. up per day for 13 consecutive days and 13 min. down, and repeated on two-week cycle) lighting; and step-up (14 min. up every second week) lighting. At 15 weeks of age, significantly larger testis and comb weights and significantly higher concentrations of plasma LH and testosterone were observed in the cockerels under the repeated slow up and down lighting regimen than those under the other lighting regimens. At 20 weeks of age, significantly larger oviduct weights and significantly higher concentrations of plasma estradiol were observed in the pullets under the repeated up and slow down, and the step-up lighting regimens than those under the other lighting regimens.

• Journal of Microbiology and Biotechnology
• /
• v.21 no.9
• /
• pp.972-978
• /
• 2011

In this study, we investigated the performance of an immobilized ${\beta}$-galactosidase inclusion bodies-containing Escherichia coli cell reactor, where the cells were immobilized in alginate beads, which were then used in repeated-batch operations for the hydrolysis of o-nitrophenyl-${\beta}$-D-galactoside or lactose over the long-term. In particular, in the Tris buffer system, disintegration of the alginate beads was not observed during the operation, which was observed for the phosphate buffer system. The o-nitrophenyl-${\beta}$-D-galactoside hydrolysis was operated successfully up to about 80 h, and the runs were successfully repeated at least eight times. In addition, hydrolysis of lactose was successfully carried out up to 240 h. Using Western blotting analyses, it was verified that the ${\beta}$-galactosidase inclusion bodies were sustained in the alginate beads during the repeated-batch operations. Consequently, we experimentally verified that ${\beta}$-galactosidase inclusion bodies-containing Escherichia coli cells could be used in a repeated-batch reactor as a biocatalyst for the hydrolysis of o-nitrophenyl-${\beta}$-D-galactoside or lactose. It is probable that this approach can be applied to enzymatic synthesis reactions for other biotechnology applications, particularly reactions that require long-term and stable operation.

• The Journal of Korean Academy of Prosthodontics
• /
• v.29 no.1
• /
• pp.281-287
• /
• 1991

This study was designed to investigate the influence of the clasp arm length on the change of retentive force with repeated placement or removal. The author measured the retentive force of Akers clasp and I-bar clasp in the depth of undercut 0.5mm, 0.25mm, respectively, varying the length of clasp arm, that is, 10mm, 14mm, 17mm in Akers clasp and 16mm, 18mm, 20mm in I-bar clasp. The retentive force was measured just before the placement of removal, after 100 times repeated placement or removal, after 300 times repeated placement or removal. The obtained results were as follows : 1. The shorter the clasp arm, the greater retention in Akers clasp and I-bar clasp(p<0.05). 2. There was decreased retentive force of Akers clasp and I-bar clasp after 300 times repeated placement or removal(p.<0.005). 3. The decreasing rate of retentive force in Akers clasp with 10mm was higher than that with 17mm, after 300 times repeated placement or removal, but there was no statistica difference(p>0.05).

• Nutrition Research and Practice
• /
• v.4 no.6
• /
• pp.477-485
• /
• 2010

The purpose of this study was to evaluate the effects of repeated fasting and refeeding on lipid metabolism. Thirty male ICR mice, aged 6 weeks, were fed an AIN-93 control diet during the experimental period. The mice were divided into 5 groups: Non fasting group (ad libitum-fed, NF), fasting for 3 days (F), fasting for 3 days and then refeeding for 4 days repeated once (FRF1), fasting for 3 days and then refeeding for 4 days repeated twice (FRF2), and fasting for 3 days and then refeeding for 4 days repeated three times (FRF3). Rates of body weight gain, epididymal fat weight, and serum TG were significantly decreased in the F, FRF1, FRF2, and FRF3 groups, compared to the NF group. LDL-cholesterol was significantly higher in the FRF3 group than the NF and F groups, but HDL-cholesterol and HDL/TC were significantly lower in the FRF3 group than in the NF and F groups. Serum total carnitine was significantly lower in the FRF1, FRF2, FRF3 groups than the NF and F groups. However, rates of serum and hepatic acyl-carnitine concentration were significantly lower in FRF1, FRF2, and FRF3 than in NF and F. Repeated tasting-refeeding resulted in visible reductions of body weight and fat mass, but it caused ill-effects with lipid and carnitine metabolism in the body.

• Food Science of Animal Resources
• /
• v.34 no.4
• /
• pp.482-495
• /
• 2014

The objectives of this study were to know the effect of repeated freeze-thaw cycles of beef on the sensory, physicochemical quality and microbiological assessment. The effects of three successive freeze-thaw cycles on beef forelimb were investigated comparing with unfrozen fresh beef for 75 d by keeping at $-20{\pm}1^{\circ}C$. The freeze-thaw cycles were subjected to three thawing methods and carried out to know the best one. As the number of freeze-thaw cycles increased color and odor declined significantly before cook within the cycles and tenderness, overall acceptability also declined among the cycles after cook by thawing methods. The thawing loss increased and dripping loss decreased significantly (p<0.05). Water holding capacity (WHC) increased (p<0.05) until two cycles and then decreased. Cooking loss increased in cycle 1 and 3, but decreased in cycle 2. pH decreased significantly (p<0.05) among the cycles. Moreover, drip loss, cooking loss and WHC were affected (p<0.05) by thawing methods within the cycles. 2-Thiobarbituric acid (TBARS) value increased (p<0.05) gradually within the cycles and among the cycles by thawing methods. Total viable bacteria, total coliform and total yeast-mould count decreased significantly (p<0.05) within and among the cycles in comparison to the initial count in repeated freeze-thaw cycles. As a result, repeated freeze-thaw cycles affected the sensory, physicochemical and microbiological quality of beef, causing the deterioration of beef quality, but improved the microbiological quality. Although repeated freeze-thaw cycles did not affect much on beef quality and safety but it may be concluded that repeated freeze and thaw should be minimized in terms of beef color for commercial value and WHC and tenderness/juiciness for eating quality.

• Toxicological Research
• /
• v.8 no.2
• /
• pp.265-272
• /
• 1992

Effects of repeated physical exercise on the carbon tetrachloride ($CCl_4$) hepatotoxicity were examined in adult female rats. Rats were introduced into a cylindrical rotating cage and forced to exercise for 1 hr each day, 6days/week, for 5 consecutive weeks at a speed starting from 10m/min, increased by 1m/min per day until the speed reached 27m/min. Significantly less body weight gain was observed in the exercise group suggesting that physical fitness had been induced in these animals. Eighteen hours following termination of the last exercise bout rats were treated with $CCl_4$(2 mmol/kg.ip). The $CCl_4$-induced heptotoxicity was significantly potentiated in the repeated exercise group compared to the resting sedentary animals as determined by changes in serum sorbitol dehydrogenase (SDH), glutamic oxaloacetic transaminase(GOT), glutamic pyruvic transaminase (GPT), and glucose-6-phosphatase(G-6-Pase) activities when measured 24hrs following the $CCl_4$ treatment. Hepatic drug metabolizing activity was determined in order to elucidate the underlying mechanism of potentiating action of the $CCl_4$ hepatotoxicity induced by repeated physical exercise. Repeated exercise increased the hepatic microsomal cytochrome P-450 contents and aminopyrine N-demethylase activity. The results suggest that the potentiation of $CCl_4$ hepatotoxicity by repeated exercise is associated with induction of the mixed function oxidase (MFO) enzyme system mediating the metabolism of $CCl_4$ to its active metabolite(s).

• The Korean Journal of Cytopathology
• /
• v.18 no.1
• /
• pp.55-61
• /
• 2007

Once diagnosed as "cell paucity"or "atypia" by the cytospin (CS) preparation, this CS preparation does not secure a precise diagnosis by repeated testing alone. Although the ThinPrep (TP) preparation is acknowledged to show increased cellularity, performing the screening tests for the cases that have enough cellularity, according to CS, raises issues for the cost-effectiveness. To obtain a more precise diagnosis through increasing the cellularity by performing TP, we selected the cases that were diagnosed as "cell paucity" or "atypia" by CS, but they required a more precise diagnosis, and the samples were processed via both CS and TP to compare the results. 11 patients diagnosed as "cell paucity" and 22 patients diagnosed as "atypia" by CS participated in this study. When the detection rate of atypical cells in both preparations with repeated urine cytology was compared, the overall detection rate of TP (16cases, 48.5%) was superior than that of CS (11cases, 33.3%), with statistical significance. The cellularity of both preparations was compared on repeated urine cytology; the general cellularity of TP (29cases, 87.9%) was higher than that of CS (20cases, 60.6%), but there was no statistical significance. Particularly, we repeated the TP for the 1 case that was diagnosed as "atypia" and we performed polyoma virus immunohistochemical staining, which confirmed polyoma virus. In conclusion, we can avoid obtaining negative diagnosis from cases with uncertain "atypia" or "cell paucity" by performing repeated TP testing.

• Journal of the Korean Geosynthetics Society
• /
• v.9 no.3
• /
• pp.57-65
• /
• 2010

The main objective of this study is to investigate the time-dependent deformation of EPS blocks under repeated loading conditions which is the one of the flexible pavement structure. The study comprised of both the experimental work and analytical modeling in order to understand the behavior of EPS blocks under repeated loading. The analytical modeling included the selection of a suitable model for describing the deformation behavior observed under repeated loading conditions, investigating the relationship among the unit weight, deformation and applied stress, analyzing the effect of repeated load on deformation. The test results were compared with the Findley's theory and model analysis with the results of this research under repeated loading conditions. Both Modified Findley's model and the proposed model can be adopted to illustrate the deformation behavior of EPS blocks under repeated loads.

• Geotechnical Engineering
• /
• v.5 no.4
• /
• pp.37-46
• /
• 1989

The object of this paper is to study the general characteristics of overconsolidated silty clays subjected to repeated loading. The samples are first remolded. overconsolidated and a series of strain - controlled triaxial repeated tests are carried out. Generally the relationship of deviator stress - axial strain of overconsolidated clay is similar in pattern to the normally consolidated clay under single load. But the behavior of the pore water pressure build up in the sample subjected to repeated loading is dependent upon the consolidation history and the level of repeated stress. Therefore through the series of the tests, the characteristics of stress -strain relationship of soils which are differentlly overconsolidated are investigated, analysed and then compared with each soils. And also, from the relationship of test results, the strength and strain characteristics of soils are obierved. The equilibrium lines which presents the critical repeated stress and equilibrium state in the sample under repeated loading, are often straight, but may be curved. And the tendency of the equilibrium lines is observed as to the variation of overconsolidation ratio.

• Fashion & Textile Research Journal
• /
• v.1 no.3
• /
• pp.288-295
• /
• 1999

This study was conducted to examine the fatigue phenomenon of mechanical properties in tencel fabrics by repeated washing & shear and tensile deformation. The obtained results are as follows. After performing repeated shear tensile deformation, RT of tencel showed higher increase rate than that of cotton and rayon, whereas its WT and EM was a smaller decrease rate than that of them. This means that tencel's resistance to tensile deformation was the greatest. In the repeated washing and shear tensile deformation, tencel's 2HB, 2HG and 2HG5 showed a remarkable increase rate. In terms of deformation frequency, the greatest change rate appeared at the time of 1000 cycles of repeated shear tensile deformation and 15 times of repeated washing. In the hand value and THV, KOSHI showed a higher increase rate for tencel than for cotton and rayon in both repeated washing and shear tensile deformation, and NUMERI showed a higher increase rate. In the THV the change rate of rayon and cotton could be rarely seen but for tencel, it decreased. tencel's change rate of thermal insulation value by materials was 1.08%, and it increased as the washing frequency increased, compared to the grey fabrics, whereas the change rates of cotton and rayon were 0.74% and 0.22%, respectively. The qmax decreased in the order of cotton>tencel>rayon as the washing frequency increased.