The ideal restorative material should mimic the properties of the tissues it replaces. Dental composite resins have been used widely as restorative materials due to its advantages such as excellent esthetics and ease of manipulation. But inadequate wear resistance has been a major factor limiting the use of composite restorative materials. Improved manufacturing techniques have allowed the development of hybrid composites, with a greater percentage volume filler loading, which have improved physical an mechanical properties. However they are lacking the study wear resistance. The purpose of this study was to evaluate the wear of human enamel against ceromer by the use of a pin-on-disk type wear testers. Discs of ceromer(Targis : Ivoclar, Vivadent, Amherst. NY) and discs of type III gold alloy as a control were used for test specimens. Intact cusp of premolar and molar were used for enamel specimens. The wear of enamel was determined by weighing the cusp before and after each test, and the weight converted to volumes by average density of enamel. Surface profilometer was used to quantify wear of the ceromer and gold specimens. Vicker's hardness tester was used to evaluate the surface hardness of test specimens. The SEM was used to evaluate the wear surfaces. The results were as follows; 1. Ceromer produced less enamel wear than gold(p<0.05). 2. The wear volume of ceromer was greater than that of gold(p<0.01). 3. The hardess of ceromer was lower than that of gold, but there was no correlation between the hardness and wear of the ceromer and gold. 4. SEM analysis revealed that there were many voids and microcracks in the wear tract of ceromer. in gold group, many minute V-shaped grooves were examined.
Alloys ; Bicuspid ; Composite Resins ; Dental Enamel* ; Esthetics ; Hardness ; Hardness Tests ; Humans* ; Molar

No abstract available.
Cisterna Magna*

No abstract available.
Beckwith-Wiedemann Syndrome*

No abstract available.
Gaucher Disease* ; Humans ; Siblings*

No abstract available.
Mycoplasma pneumoniae* ; Mycoplasma* ; Pneumonia* ; Pneumonia, Mycoplasma*

OBJECTIVES: The neural substrate of fear is thought to be highly conserved among species including human. The purpose of this review was to address the neural substrates of fear based on recent findings obtained from animal and human studies. METHODS: Recent studies on brain regions related to fear, particularly fear conditioning in rodents and humans, were extensively reviewed. RESULTS: This paper suggests high consistency in anatomical structure and physiological mechanisms for fear perception, response, learning and modulation in animals and humans. CONCLUSIONS: Fear is manifested and modulated by well conserved neural circuits among species interconnected with the amygdala, such as the hippocampus and the ventromedial prefrontal cortex. Further research is required to incorporate findings from animal studies into a better understanding of neural circuitry of fear in human in a translational approach.
Amygdala ; Animals ; Brain ; Hippocampus ; Humans ; Learning ; Neuroanatomy ; Prefrontal Cortex ; Rodentia

No abstract available.

No abstract available.

Early-life stress (ELS), a complex traumatic stress including abuse, neglect and bullying during childhood or adolescence, is closely related to the development of psychiatric disorders. Conduct of a prospective study on the effect of ELS in human subjects is difficult due to ethical issues and limitations, and animal model study can be a reasonable alternative. Articles regarding structural and functional changes in the animal brain associated with ELS have been reviewed in this study. An up-to-date literature search on the effect of ELS on animal brain was performed ; keywords included ELS, central nervous system (CNS), and animal study using PubMed. A total of 623 articles were found and important articles were reviewed. First, we summarized the neurobiological changes in CNS associated with ELS, and then the effects of ELS on emotional and cognitive function and behavioral characteristics were recapped. ELS can induce overreactivity of the hypothalamus-pituitary-adrenal axis and cortical-subcortical structural changes including prefrontal cortex, hippocampus, and amygdala. These changes may be associated with neuroendocrine, cognitive, and emotional dysfunctions and related behavioral changes. Although most animal model studies used a single mode of stress, ELS tends to be experienced with complex types in human-life. Design of a new animal model examining the effects of complex trauma during early-life is important. Studies on the association between complex trauma and brain development can provide important insights regarding the pathogenetic mechanism of complex psychiatric disorders such as personality disorder and treatment-resistant depression.
Adolescent ; Amygdala ; Animals* ; Brain ; Bullying ; Central Nervous System* ; Cognition ; Depression ; Ethics ; Hippocampus ; Humans ; Models, Animal* ; Personality Disorders ; Prefrontal Cortex ; Prospective Studies

PURPOSE: To assess the factors which are related to recovery time from overcorrection that occurred immediately after surgery. METHODS: We reviewed the medical records of intermittent exotropia patients who had undergone bilateral lateral rectus muscle recession from February 2002 to July 2004. Fifty patients who developed overcorrection of less than 20 PD on the immediate postoperative day were included in this study. Age at surgery, sex, refractive power, preoperative deviation angle, Worth 4-dot test, and stereopsis were examined, and we evaluated the correlation between these factors and recovery time. RESULTS: Thirty-six patients (72%) recovered to orthoposition within 4 weeks postoperatively. Significant correlations were found between the recovery time and poor stereopsis (p=0.02), and suppression of the Worth 4-dot test (p=0.01). There was no significant relationship between the recovery time and age at surgery, sex, refractive power, and preoperative deviation angle. CONCLUSIONS: In cases of immediate postoperative overcorrection of less than 20 PD after intermittent exotropia surgery, factors related to delayed recovery were poor stereopsis and suppression of the Worth 4-dot test.
Depth Perception ; Exotropia* ; Humans ; Medical Records