• Toxicological Research
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• v.17 no.4
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• pp.287-296
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• 2001

The acute oral LD5O toxicity values of isazofos, pyraclofos, diazinon and methomyl were determined for Japanese quail based on OECD guideline. The $LD_{50}$ of isazofos, pyraclofos and diazinon was 16.26 mg/kg, and 7.11mg/kg body weight In female respectively. And the $LD_{50}$ of each chemical in male was 21.44, 35.64, 8.28 mg/kg body weight respectively. Diazinon was the most susceptible compounds to Japanese quail in both sexes. The $LD_{50}$ of methomyl was 21.24 mg/kg body weights in female, and 28.28 mg/kg body weight in male respectively. Diazinon, isazofos and methomyl were more toxic In the female than male. The symptoms of poisoning were similar in quails administrated with each chemicals. The clinical sign in Japanese quail were ataxia, salivation, diarrhea, ruffled feather and convulsion at dead point. There were severe hemorrhage and catarrhal inflammation from duodenum to ileum In all compounds. In Japanese quail treated with organophosphorus and carbamate compounds, brain acetylcholinesterase was inhibited by 88-96. The recovery was not observed after 5 h in sublethal dose.

• Health Policy and Management
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• v.14 no.1
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• pp.148-168
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• 2004

To investigate the effect of parents' social class on birthweight in Korea during the period of transition to a market economy, 1995-2001. Methods: All births resulting from pregnacies reported in 1995-22001(n=4,298,374) were studied with respect to social variation in birthweight. The results were adjusted for maternal age, parity, parents' education, gestational age, total births, the dead births among total births, the number of births in one delivery. Results: Between 1995 and 2001, mean birth weight was 3271g and low birth rate was 3.41%. Maternal education, faternal education, parents' occupation, the number of birth in one delivery, total births, gestational age, and the number of deaths among. total births were all independently related to the birthweight. Parents with lower education showed higher low-birthweight rates compared with parents with university level of education(OR: 2.16 for mother and 1.68 for father). Especially, mother's education showed stronger relationship with birthweight than fathers' education. The differences in birth weight by parents' social class, especially parents' educational level became stronger between 1995 and 2001. Discussion: This study suggests that the social differences of birth weight were increasing in order 1995 to 2001. Especially, this increasing tendency in variation in birth weight by social class was shown after economic crisis, 1998.

• Toxicological Research
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• v.11 no.1
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• pp.81-89
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• 1995

A teratogenicity study of KTC-1, a new semisynthetic rifamycin antituberculous drug, was conducted in Sprague-Dawley rats. Dosages of KTC-1 0, 7, 21, and 63 mg/kg/day were administered to darns orally gayage from day 7 to day 17 of gestation. Two-third of dams per group were subjected to cesarean section on day 21 of pregnancy for examination of their fetuses, and the remaining one-third of darns per group were allowed to deliver naturally for postnatal examination of their offspring. At 21 mg/kg/day, an increase in the skeletal variations of F1 fetuses and a decrease in the body weight of F1 offspring were seen. At 63 mg/kg/day, a loss in body weight was observed in darns. An increase in fetal death rate, a decrease in litter size and body weight, and an increase in the incidence of visceral malforrnations and skeletal variations were found in F1 fetuses. In particular, lumar rib occurred at an incidence of 31%. In addition, an increase in the dead newborns at birth and neonatal deaths during the lactation period, a loss in body weight, and a decrease in spleen weight were observed in F1 offspring. There were no signs of maternal toxicity or embryotoxicity at 7 mg/kg/day. The results suggest that the no-effect dose level(NOEL)for dams is 21 mg/kg/day, and NOELs for F1 fetuses and offspring are 7 mg/kg/day.

• Structural Engineering and Mechanics
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• v.58 no.1
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• pp.143-161
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• 2016

Utilization of mineral and chemical admixtures in concrete technology has led to changes in the formulation and mix design in recent decades, which has, in turn, made the concrete stronger and more durable. Lightweight concrete is an excellent solution in terms of decreasing the dead load of the structure, while self-compacting concrete eases the pouring and removes the construction problems. Combining the advantages of lightweight concrete and self-compacting concrete is a new and interesting research topic. Considering its light weight of structure and ease of placement, self-compacting lightweight concrete may be the answer to the increasing construction requirements of slender and more heavily reinforced structural elements. Twenty one laboratory experimental investigations published on the mix proportion, density and mechanical properties of lightweight self-compacting concrete from the last 12 years are analyzed in this study. The collected information is used to investigate the mix proportions including the chemical and mineral admixtures, light weight and normal weight aggregates, fillers, cement and water. Analyzed results are presented in terms of statistical expressions. It is very helpful for future research to choose the proper components with different ratios and curing conditions to attain the desired concrete grade according to the planned application.

• Clinical and Experimental Pediatrics
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• v.53 no.2
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• pp.167-172
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• 2010

Purpose : With improved survival of extremely low birth weight infants (ELBWI), there is an increase in the incidence of necrotizing enterocolitis (NEC) requiring laparotomy, and the risk of morbidity and mortality in these ELBWI is increased. Thus, we determined the prognostic factors in ELBWI who underwent laparotomy for NEC. Methods : We retrospectively reviewed the medical records of 35 ELBWI who underwent laparotomy for NEC from January 2001 to December 2008 at Samsung Medical Center. Results : Of 480 ELBWI, 35 required laparotomy for NEC; the mortality rate was 20% (Alive group n=28, Dead group n=7). The values of preoperative score for neonatal acute physiology-II (P =0.022) and fraction of inspired oxygen (P <0.001) were significantly higher in the dead group and values of base excess (P =0.004) were significantly lower in the dead group. Values of preoperative heart rate, respiration rate, mean blood pressure, pH, $CO_2$, and potassium ion were not significantly different between the study groups. Intraoperative fluid volume was significantly higher in the alive group than in the dead group (P =0.045). Postoperative infusion rate was significantly lower in the alive group than in the dead group (P =0.022). Conclusion : Good preoperative condition, more intraoperative fluid infusion, and stable postoperative hemodynamic condition were factors associated with favorable prognosis of laparotomy for NEC in ELBWI.

• Structural Engineering and Mechanics
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• v.52 no.4
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• pp.723-738
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• 2014

Prestressing is the most commonly employed technique in bridges and long span beams in commercial buildings as prestressing results in slender section with higher load carrying capacities. This work is an attempt to study the performance of a minimum weight prestressed concrete beam adopting a non-prismatic section so that there will be a reduction in the volume of concrete which in turn reduces the self-weight of the structure. The effect of adopting a non-prismatic section on parameters like prestressing force, area of prestressing steel, bending stresses, shear stresses and percentage loss of prestress are established theoretically. The analysis of non-prismatic prestressed beams is based on the assumption of pure bending theory. Equations are derived for dead load bending moment, eccentricity, and depth at any required section. Based on these equations an algorithm is developed which does the stress checks for the given section for every 500 mm interval of the span. Limit state method is used for the design of beam and finite difference method is used for finding out the deflection of a non-prismatic beam. All the parameters of nonprismatic prestressed concrete beams are compared with that of the rectangular prestressed concrete members and observed that minimum weight design and economical design are not same. Minimum weight design results in the increase in required area of prestressing steel.

• Toxicological Research
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• v.22 no.4
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• pp.439-443
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• 2006

This study was conducted to investigate the potential acute toxicity of Aralia elata by a single oral dose in ICR mice. Thirty mice of each sex were randomly assigned to three groups of 10 mice each. The test articles were administered once by the gavage to mice at dose levels of 0, 2,500 and 5,000 mg/kg body weight. The mortality and changes on body weight and clinical signs of gross observation were monitored for 14 days after dosing. At the end of 14-day observation period, all animals were sacrificed and complete gross postmortem examinations were performed. There were no dead animal and adverse effects on clinical signs, the body weight and the gross finding. As the results, we could not find any toxic effect at the dose levels of 2,500 or 5,000 mg/kg in mice and the minimal lethal dose was considered to be over 5,000 mg/kg body weight in mice.

• Biomolecules & Therapeutics
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• v.8 no.1
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• pp.84-92
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• 2000

This Study was conducted to assess the single dose toxicity of DA-125, a new anthracycline anti-cancer agent, in rats and mice. The Drug was administered once intravenously to both sexes of rats and mice. Then followed a 14-day period of observation. The $LD_{50}$ Values (95% confidence limit) were estimated to be 60.9 mg/kg (57.5~64.3 mg/kg) for male rats and 60.2 mg/kg (56.2~64.5 mg/kg) for female rats, and 85.8 mg/kg (81.0~90.9 mg/kg) for male mice and 84.5 mg/kg (78.2~91.9 mg/kg) for female mice. Both sexes of rats and mice given the drug revealed the clinical sign of decreased locomotor activity, emaciation, hair loss, red-dish brown urine, salivation, and watery diarrhea. In addition, body weight from the next day to the 7th day tended to be decreased slightly in rats and mice treated with DA-125. Death occurred from the next day after administration to the 12th day. Macroscopically, congestion of gastrointestinal organ, lung, and adrenal glands were found in both sexes on the dead rats and mice. Histopathological examination of dead rats manifested atrophy of spleen, hypoplasia of bone marrow, hypcplasia and necrosis of lymphocyte in thymus, atrophy of villi in small intestine (duodenum, jejunum, and ileum), hyperplasia of granular epithelium in small intestine, degeneration of germinal epithelium in testis, defer oration of tubular epithelium in kidney, and vacuolation and myolysis of myocardium in heart. Histopathological examination of dead mice revealed hypoplasia of spleen and mesenteric lymph node, local necrosis of liver, atrophy of villi in small intestine, hyperplasia of glandular epithelium in small and large intestine, degeneration of tubular in kidney, degeneration of germinal cells in testis, and slight vacuolar degeneration of myocardium in heart.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.1
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• pp.1-6
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• 2002

Eggs obtained from 46 and 42 weeks old meat (Hybro) and layer (Leghorn) breeders flocks, respectively were used to examine the effects of genetic type of birds and egg size (small, medium and large) on variables of eggshell characteristics and hatchability traits. The variables measured were egg weight (EW), egg surface area (ESA) and eggshell characteristics (shell conductance (EC), per cent shell (PS), shell thickness (ST), shell volume (SV), shell density (SD) and hatchability traits (per cent hatchability (HP), early dead embryos (ED), late dead embryos (LD), pips with live embryos (PL) and pips with dead embryos (PD)). Genetic type of bird influenced all egg characteristics and HP of eggs. Eggs produced by the small Leghorn bird had lower EW, ESA, EC, ST, SV and HP than those produced by the heavy Hybro bird. The reduction of HP was associated with an increase in the percentage of ED and PL. Egg size influenced all variables measured except ST. Small size eggs had lower EW, ESA and EC and higher PS and SD than those of large eggs. Medium size eggs produced a higher HP when compared with that of large size eggs. The reduction of HP in large eggs was associated with higher percentage of ED, LD and PL. There were significant interactions between the genetic group of birds and egg size on LD and HP. Large egg size of Hybro birds had higher LD and lower HP than those of small size eggs produced by the same flock. However, There was no difference in HP and LD among the different egg sizes produced by Leghorn birds. It was concluded that genetic make up of birds and egg size influence eggshell characteristics and HP. The type of bird (heavy or small) influences the optimum egg size for successful hatching. Attention should be given to the size and eggshell characteristics of eggs of breeders' flocks for achieving maximum HP.

• Structural Engineering and Mechanics
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• v.71 no.6
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• pp.603-625
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• 2019

Main cable configurations under final dead load and in the unloaded state and critical construction parameters (e.g. unstrained cable length, unstrained hanger lengths, and pre-offsets for tower saddles and splay saddles) are the core considerations in the design and construction control of a suspension bridge. For the purpose of accurate calculations, it is necessary to take into account the effects of cable strands over the anchor spans, arc-shaped saddle top, and tower top pre-uplift. In this paper, a method for calculating the cable configuration under final dead load over a main span, two side spans, and two anchor spans, coordinates of tangent points, and unstrained cable length are firstly developed using conditions for mechanical equilibrium and geometric relationships. Hanger tensile forces and unstrained hanger lengths are calculated by iteratively solving the equations governing hanger tensile forces and the cable configuration, which gives careful consideration to the effect of hanger weight. Next, equations for calculating the cable configuration in the unloaded state and pre-offsets of saddles are derived from the cable configuration under final dead load and the conditions for unstrained cable length to be conserved. The equations for the main span, two side spans and two anchor spans are then solved simultaneously. In the proposed methods, coupled nonlinear equations are solved by turning them into an unconstrained optimization problem, making the procedure simplified. The feasibility and validity of the proposed methods are demonstrated through a numerical example.