• Journal of the Korea Institute of Military Science and Technology
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• v.4 no.2
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• pp.42-51
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• 2001

The effects of pre-indentation technique are presented for A12024-T3 Alclad alloy using as skin material for aircraft fuselage and wing. Indentations were applied to specimens to be placed on the presumed path of fatigue crack growth before fatigue tests. Tension-tension fatigue tests were conducted on the edge cracked specimens in the L-T orientation. Test results were analyzed to investigate the effectiveness of pre-indentation with the variation of specimen's thickness, position of indentation and applied maximum stress. Fatigue crack retardation by pre-indentation is well recognized in the various conditions.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.23 no.1
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• pp.31-35
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• 2012

Noonan syndrome is characterized by short stature, typical facial dysmorphology, and congenital heart defects. The main facial features of Noonan syndrome are hypertelorism with down-slanting palpebral fissures, ptosis, and low-set posteriorly-rotated ears with a thickened helix. The cardiovascular defects most commonly associated with this condition are pulmonary stenosis and hypertrophic cardiomyopathy. Other associated features are webbed neck, chest deformity, mild intellectual deficit, cryptorchidism, poor feeding in infancy, bleeding tendency, and lymphatic dysplasias. The patient is a 10-year-old boy. He had experienced repeated febrile convulsions. He had typical facial features, a short stature, chest deformity, cryptorchidism, vesicoureteral reflux, and mental retardation. His language and motor development were delayed. When he went to school, it was difficult for him to pay attention, follow directions, and organize tasks. He also displayed behavior such as squirming, leaving his seat in class, and running around inappropriately. Clinical observation is important for the diagnosis, so we report a patient who was diagnosed with Noonan syndrome, mental retardation, and attention-deficit hyperactivity disorder.

• Animal cells and systems
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• v.6 no.3
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• pp.247-252
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• 2002

The effect of paraquat (PQ, 1,1＇-dimethyl-4,4＇-bipyridium) on the histogene-sis and glycoconjugates (GCs) properties of the pyloric region of the stomach in a perinatal rat was examined by histological and histochemical methods. Oral administration of PQ (9 mg/kg per day in 0.2 mL of D.W.) on 7 to 14 days of gestation revealed growth retardation with significant reductions in the length of pyloric gland and their pit. As for histochemical properties of GCs in the pyloric region of the stomach, the PQ-treated rats showed some differences, such as delayed initial appearance of the sulfated GCs and lectin affinities compared with the vehicle group. These different GCs properties in the surface and gastric pit were usually detected in the fetal rats and more prominent and evident differences were revealed in the gland epithelium of the early postnatal rat. These results suggest that maternal PQ administration causes intrauterine growth retardation asso-ciated with delayed histogenesis and GCs immaturation of pyloric mucosa in developing rat.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.3
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• pp.15-22
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• 2003

The fatigue crack growth model is derived and the retardation model is proposed. The fatigue crack growth model considers the residual plastic stretch on the crack surface which results from the plastic deformation at the tip of fatigue crack. The fatigue crack growth rate is calculated by using the cumulative fatigue damage and plastic strain energy in the material elements at the crack tip. This model gives the crack growth rate in reasonable agreement with test data for aluminum alloy AL6061-T651 and 17-4PH casting steel. The fatigue crack growth retardation model is based on the residual plastic stretch produced from a tensile overload which reduced the plastic strain range of the following load cycles. A strip-yield model of a crack tip plasticity is used for the calculation of a plastic zone size. The proposed retardation model characterized the observed features and delayed retardation of the fatigue crack growth under tensile overload.

• Journal of Yeungnam Medical Science
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• v.9 no.2
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• pp.427-435
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• 1992

We have experienced a case of infantile nephrotic syndrome confirmed by renal biopsy in a 13-month-old female patient who showed growth and develop mental retardation and persistent proteinuria. She revealed mild eyelid edema, joint laxity, delayed speech development and adrenal cortical calcification on the radiologic study. Renal biopsy showed microcystic tubular change, micro-glomeruli and marked mesangial proliferation.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.15 no.3
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• pp.118-126
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• 2015

Background and objectives: A deficiency of BH4 (tetrahydrobiopterin) not only causes the classical phenylketonuric phenotype, but also is the source of neurological signs and symptoms due to impaired syntheses of L-Dopa and serotonin. The treatment of BH4 deficiency usually consists of replacement with BH4 and the neurotransmitters. We performed this study to finding out long-term follow-up clinical symptoms and prognosis of BH4 deficiency. Methods: Clinical and biochemical, genetic analysis were done retrospectively from January 1999 to July 2015 in Soonchunhyang University Hospital. Results: In our study, total 207 patients were confirmed to hyperphenylalaninemia. Among them, 10 patients were BH4 deficiency. 9 patients were 6-pyruvoyl-tetrahydropterin (PTPS) deficiency and one patient was dihydropteridine reductase (DHPR) deficiency. The patients who received delayed treatment, most of our patients suffered from severe psychomotor retardation, hypotonia and seizure. c.259C>T mutation was identified most commonly in PTPS gene analysis. A patient with DHPR deficiency had a mental retardation, dystonia, seizure. His seizure semiology was dialeptic feature. His EEG showed generalized spike wave patterns. All patients had treated with tolerate L-Dopa, BH4 and 5-hydroxytryptophan. Most of the early treated patients have a good tolerance for drugs well. But some patients had neurologic symptoms, despite early detection and treatment. Conclusion: BH4 deficiency patients who had delayed treatment tend to have severe psychomotor problem and neurologic deficits.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.14 no.1
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• pp.123-127
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• 2003

Cornelia de Lange syndrome is a dysmorphogenic disorder characterized by multiple congenital abnormalities, mental retardation, growth retardation and neurodevelopmental abnormalities. Diagnosis for the Cornelia de Lange syndrome is dependent on the clinical observation because neither definite biological marker nor definite chromosomal abnormality have been investigated. Clinical observation is important for the diagnosis, so we report a case of Corenelia de Lange syndrome with mental retardation and autistic disorder. The patient is a 6-year old girl. Her motor development and language development have been delayed. She could say no meaningful word and understood simple command partially. She showed poor eye contact and poor emotional interaction. Social interaction was impaired and she Showed stereotypic behaviors. Thus we diagnosed her as mental retardation with autistic disorder. She had vesicoureteral reflux, frequent upper respiratory infection and pneumonia. She had experienced febrile convulsions 4 times. She had short stature, confluent eyebrows, long eyelashes, and upturned nose with anteverted nostrils. She also showed low hairline and hypertrichosis in body and extremities. Her finger was short. In this case, we diagnosed Cornelia de Lange syndrome by her characteristic face, hypertrichosis and medical and behavioral problems that were frequently showed in this syndrome.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.6 no.4
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• pp.80-88
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• 1997

An experimental investigation of the fatigue through crack growth behavior under simple stepped variable loading condition has been performed using Al7075-T651. Experiments were carried out by using cantilever bending type specimens, with chevron notches on a small electro-magnetic test machine. Tensile overloads have a retarding effect on the fatigue crack growth rates, therefore tensile overloads were used for the beneficial effect on the fatigue life. While in most cases compressive overloads have only a vanishing effect on crack growth rates, some experiments with single edge crack tension specimens reveal a marked growth retardation. The stress ratios used in this investigations varies from R=0.32 to 0.81, from R=0.04 to 0.76, from R=-0.15 to 0.73, and from R=-0.33 to 0.68 and the peak load for each case was not varied. The crack growth and crack closure were measured by Kikukawa's compliance method with a strain gauge mounted on the backside of each specimens. The results obtained are as follows. When the stepped variable load was applied, the smaller the stress ration was, the larger the delayed retardation of the crack growth rate was. The fatigue crack growh rate data obtained for through cracks were plotted well against the effective stress intensity factor range from 4.0 to 20.0MP{a^{SQRT}m}. It was found that the effective stress intensity factor range ratio was related well to the opening stress intensity factor, the maximum stress intensity factor, and crack length.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.4
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• pp.1025-1029
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• 2007

It is widely assumed that Intelligence Quotient (IQ) is determined by inherent disposition and environmental factor. IQ is estimated by age-conversion score and stabilized around age 4 and IQ of adult age can be predicted after age 10. Though children with Mental Retardation (MR) are delayed in language development since early infant period, they receive only special education including speech and language therapy, but no special medication. In traditional Korean medicine, the etiology and treatment for developmental delay of language have been handed down for a long time. Some studies on herbs and prescriptions for improving language development have been undertaken recently. We have found several cases of significant elevation of IQ in the children treated with long term medications of Korean herbal medicine for improvement of language. Analyzing these cases, especially performance IQ showed significant change. Therefore we suggest that Korean herbal medicine might improve cognition development in children with MR.

• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.1
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• pp.51-56
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• 2002

Russell-Silver syndrome is a type of intrauterine growth retardation, characterized by short stature noted at birth, hemiatrophy or asymmetry, variation in sexual development and other abnormalities, including cafe-aulait pigmentation and clinodactyly. Facial features commonly associated with this syndrome are a small triangular face, decreased facial height, down-turned corners of the mouth(shark's mouth), a small mandible, and occasionally asymmetry. The major intra-oral features of the syndrome that have been reported are a high-arched palate, delayed tooth eruption, microdontia, hypodontia, and crowding. These cases were diagnosed at birth as Russell-Silver syndrome by clinical features such as prenatal growth retardation, short stature, low body weight, et al., and have been treated with growth hormone. The purpose of this paper is to report the dental findings of two patients and review the pertinent literature through the two cases.