Minimization of Surface Roughness and Machining Deformation in Milling of Al Alloy Thin-Walled Parts

De-Jun Cheng,Feng Xu,Sheng-Hao Xu,Chun-Yan Zhang,Sheng-Wen Zhang,Su-Jin Kim 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.9

This study focused on investigating the surface roughness in the feed direction (R a -Fd), surface roughness in the transversedirection (R a -Td), and thin-walled parts deformation (TWD) during milling of Al alloy 5083. The response surface method(RSM) was used to conduct experiments and establish the models of R a -Fd , R a -Td , and TWD under various cutting parameters. The significance of cutting parameters on R a -Fd , R a -Td , and TWD was analyzed by analysis of variance. It was observedthat the R a -Fd and R a -Td are mainly influenced by the spindle speed, depth of cut, transverse size and feed rate, while the TWD is mainly influenced by the depth of cut. A comparison of RSM-optimum function and artificial bee colony (ABC)algorithm optimum programming was conducted to obtain the best cutting conditions leading to minimum R a -Fd, R a -Td and TWD simultaneously. From the presented results, ABC algorithm was able to obtain the better cutting strategy. Finally, theperformance of the proposed cutting strategy was verified by confirmation experiments.

EFFECTS OF CARBON NANOTUBES ON RAT LIVER AND BRAIN

FU-DE WANG,CHAN JIN,LING-LING CAO,HAO LIANG,CHUN-WANG MA 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.7

Carbon nanotubes (CNTs) have been widely applied in various ¯elds due to excellent physicaland chemical properties. As production and applications of nanotubes expand, public concernabout their potential risks to human health has also risen. In the present study, the e®ects ofCNTs on rat liver and brain by single intratracheal instillation were detected. CNTs [eithersingle-walled carbon nanotubes (SWCNTs) or multi-walled carbon nanotubes (MWCNTs)] couldbe seen in the lung and liver indicating the transfer of CNTs by blood stream. CNTs could induceoxidative stress in liver with elevated Malondialdehyde (MDA) level and degressive GSH level,superoxide dismutase (SOD) and CAT activity. To brain, maybe due to the blood brain barrierand the increased SOD and CAT activity, serious oxidative stress of brain did not occur.

NANOTOXICITY OF MULTIWALL CARBON NANOTUBES TO A549 CELLS IN VITRO

FU-DE WANG,Ying Tang,Yong Ji Yang,CHAN JIN,HUA ZHANG,HAO LIANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.2

Multiwall carbon nanotubes (MWCNTs) have been widely applied in many ¯elds due to theexcellent physical and chemical properties. As the production and applications of nanotubesexpand, public concern about their potential risks to human health has also raised. Cytotoxicityof MWCNTs was evaluated in this study using a cultured human epithelial cell line A549. Uptakeof MWCNTs by cultured A549 cells was observed by TEM imaging. Dose-dependent decrease ofcell viability showed the cytotoxicity of MWCNTs. Signi¯cant reactive oxygen species (ROS)generation and GSH depletion which reduced the cellular antioxidant level could be the majorfactor of cytotoxicity induced by MWCNTs. MWCNTs seemed to trigger the activation of cellautophagy with the intracellular ATG16L1 level increase as a defense mechanism.

Gastrin 유발 위점막 손상에 대한 Nicotine의 보호 효과

박세호(Shi Hao Piao),김동구(Dong Goo Kim),김덕남(De Nan Jin),오정구(Zhen Jiu Wu),홍춘란(Chun Lan Hong),김경환(Kyung Hwan Kim) 대한약리학회 1995 대한약리학잡지 Vol.31 No.3

Conflicting data have been reported on the effect of nicotine on gastric mucosal damage. To elucidate the effect of chronic intermittent nicotine on gastric mucosal damage, intragastric nicotine (5 mg/kg, 10 mg/kg) was administered twice per day for 9 days. Gastric mucosal damage was created by s.c. injection of a large dose (1.2 mg/kg) of pentagastrin followed by pylorus ligation for 6 hours. Nicotine treated rats showed reduced gastric mucosal damage about 50% of the control. To examine the mechanism of the protective effect of nicotine, gastric perfusion experiments were done. Basal acid secretion was not affected by intragastric or intravenous nicotine. However, pentagastrin-stimulated acid secretion markedly inhibited by a bolus injection of nicotine, and this response was dose-related. These data indicates that chronic intermittent administration of nicotine protects gastric mucosa against gastrin-induced gastric mucosal damage, and nicotine-induced inhibition of gastrin-stimulated acid secretion has an important role for the protective effect of nicotine. Considering reports concerning nicotine s aggravating effect on the gastric mucosal damage, it is suggested that the methods of administration of nicotine may be an important decisive factor of the divergent action of nicotine on the gastric mucosa. 위점막 손상에 미치는 영향에 관한 nicotine의 효과는 아직 정설이 없는 형편이다. 본 연구에서는 nicotine이 위점막 손상에 미치는 영향을 보기 위하여 nicotine (5 mg/kg, 10mg/kg)을 9일간 하루에 두번씩 위내 투여하였다. 위점막 손상은 gastrin (1.2 mg/kg)을 피하 주사함과 동시에 유문부결찰을 6시간 동안 시행하므로 야기시켰다. 그 결과 nicotine 투여군에서 현저한 위점막 손상의 감소를 보였다 (대조군의 50%). 이러한 nicotine의 위점막 보호 효과에 대한 기전을 추구하기 위하여 위관류 실험을 시행하였다. Nicotine은 기초 위산 분비에는 영향이 없었으나 gastrin으로 자극된 위산 분비를 현저히 감소시켰고, 이러한 반응은 nicotine 용량에 비례하였다. 이상의 결과로 보아 nicotine의 장기간 간헐적 투여는 gastrin 투여로 인한 위점막 손상에 보호 효과가 있으며, 이러한 효과는 gastrin으로 자극된 위산 분비를 억압하는 nicotine의 효과가 관련될 것으로 생각된다. 또한 nicotine의 위점막 손상 악화 효과를 관찰한 보고들을 고려하면 nicotine의 위점막 손상에 관한 효과는 nicotine의 투여 방법에 따라 전혀 다르게 나타날 수 있을 것으로 생각된다.

Meta-analysis of Gene Expression Data Identifies Causal Genes for Prostate Cancer

Wang, Xiang-Yang,Hao, Jian-Wei,Zhou, Rui-Jin,Zhang, Xiang-Sheng,Yan, Tian-Zhong,Ding, De-Gang,Shan, Lei Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.1

Prostate cancer is a leading cause of death in male populations across the globe. With the advent of gene expression arrays, many microarray studies have been conducted in prostate cancer, but the results have varied across different studies. To better understand the genetic and biologic mechanisms of prostate cancer, we conducted a meta-analysis of two studies on prostate cancer. Eight key genes were identified to be differentially expressed with progression. After gene co-expression analysis based on data from the GEO database, we obtained a co-expressed gene list which included 725 genes. Gene Ontology analysis revealed that these genes are involved in actin filament-based processes, locomotion and cell morphogenesis. Further analysis of the gene list should provide important clues for developing new prognostic markers and therapeutic targets.

Anatomical Study of the Accessory Tendon of the Extensor Hallucis Longus Muscle and Its Clinical Application

Yue Li,Jing-Ying Zhang,Xin-Yue Zhao,Li-Ya Pan,De-Hao Jin,He-Xing Xu,Hu-Zhe Cui,Yan-Qun Liu,Xiang-Zheng Qin,Qingyuan Li 대한정형외과학회 2021 Clinics in Orthopedic Surgery Vol.13 No.2

Background: The accessory tendon of the extensor hallucis longus (ATEHL) muscle is a common abnormal structure, and its clinical significance remains debatable. In this study, we provide the incidence of the ATEHL and characterize its morphological types in Asian cadavers and investigate its clinical applications. Methods: The tendons from 50 adult cadaveric feet, fixed in 10% formalin, were analyzed. We measured the length and width of both the ATEHL and the extensor hallucis brevis (EHB). Results: All dissected specimens had an ATEHL. The first metatarsophalangeal joint was surrounded by an accessory tendon that inserted onto the joint capsule and the dorsal base of the proximal phalanx. We classified the ATEHL into 3 types based on their directions. Differences in ATEHL type based on sex were not statistically significant. Conclusions: We found an ATEHL in all cadaveric specimens in this study. We surmise that the ATEHL acts as an antagonist with the EHB when the toe is extending, which might help prevent the occurrence of hallux valgus deformity.

Protective Effect of Nicotine on Gastrin-induced Gastric Mucosal Damage in Rats

박세호,김동구,김덕남,오정구,홍춘란,김경환,Piao, Shi-Hao,Kim, Dong-Goo,Jin, De-Nan,Wu, Zhen-Jiu,Hong, Chun-Lan,Kim, Kyung-Hwan The Korean Society of Pharmacology 1995 대한약리학잡지 Vol.31 No.3

위점막 손상에 미치는 영향에 관한 nicotine의 효과는 아직 정설이 없는 형편이다. 본 연구에서는 nicotine이 위점막 손상에 미치는 영향을 보기 위하여 nicotine (5 mg/kg, 10mg/kg)을 9일간 하루에 두번씩 위내 투여하였다. 위점막 손상은 gastrin (1.2 mg/kg)을 피하 주사함과 동시에 유문부결찰을 6시간 동안 시행하므로 야기시켰다. 그 결과 nicotine 투여군에서 현저한 위점막 손상의 감소를 보였다 (대조군의 50%). 이러한 nicotine의 위점막 보호 효과에 대한 기전을 추구하기 위하여 위관류 실험을 시행하였다. Nicotine은 기초 위산 분비에는 영향이 없었으나 gastrin으로 자극된 위산 분비를 현저히 감소시켰고, 이러한 반응은 nicotine 용량에 비례하였다. 이상의 결과로 보아 nicotine의 장기간 간헐적 투여는 gastrin 투여로 인한 위점막 손상에 보호 효과가 있으며, 이러한 효과는 gastrin으로 자극된 위산 분비를 억압하는 nicotine의 효과가 관련될 것으로 생각된다. 또한 nicotine의 위점막 손상 악화 효과를 관찰한 보고들을 고려하면 nicotine의 위점막 손상에 관한 효과는 nicotine의 투여 방법에 따라 전혀 다르게 나타날 수 있을 것으로 생각된다. Conflicting data have been reported on the effect of nicotine on gastric mucosal damage. To elucidate the effect of chronic intermittent nicotine on gastric mucosal damage, intragastric nicotine (5 mg/kg, 10 mg/kg) was administered twice per day for 9 days. Gastric mucosal damage was created by s.c. injection of a large dose (1.2 mg/kg) of pentagastrin followed by pylorus ligation for 6 hours. Nicotine treated rats showed reduced gastric mucosal damage about 50% of the control. To examine the mechanism of the protective effect of nicotine, gastric perfusion experiments were done. Basal acid secretion was not affected by intragastric or intravenous nicotine. However, pentagastrin-stimulated acid secretion markedly inhibited by a bolus injection of nicotine, and this response was dose-related. These data indicates that chronic intermittent administration of nicotine protects gastric mucosa against gastrin-induced gastric mucosal damage, and nicotine-induced inhibition of gastrin-stimulated acid secretion has an important role for the protective effect of nicotine. Considering reports concerning nicotine's aggravating effect on the gastric mucosal damage, it is suggested that the methods of administration of nicotine may be an important decisive factor of the divergent action of nicotine on the gastric mucosa.