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연속파형 Nd:YAG 레이저를 이용한 SM45C 용접특성
유영태,노경보,오용석 朝鮮大學校 機械技術硏究所 2002 機械技術硏究 Vol.5 No.2
The Nd:YAG laser in combination with the optical fiber increase the automation and the flexibility of a whole industry. The Nd:YAG laser welding process in one of the most advanced manufacturing technologies owing to its high speed and penetration. This paper describes the weldability of SM45C carbon steel for machine structural use by Nd:YAG laser. Major process parameters were position of focus, travel speed and laser power. The results showed that peneration depth of the weld was increased with increasing applied laser power. Microstructural examinations and calculations and indicated that the microstructure of the laser weld, which experienced very high heating and cooling cycle during welding process. The results of this study provide application possibility of Nd:YAG laser welding for SM45C carbon steel
You, Kwon Tae,Li, Long Shan,Kim, Nam-Gyun,Kang, Hyun Ju,Koh, Kwi Hye,Chwae, Yong-Joon,Kim, Kyoung Mi,Kim, Yoon Ki,Park, Sung Mi,Jang, Sung Key,Kim, Hoguen,Wickens, Marv Public Library of Science 2007 PLoS biology Vol.5 No.5
<▼1><P>Frameshift and nonsense mutations are common in tumors with microsatellite instability, and mRNAs from these mutated genes have premature termination codons (PTCs). Abnormal mRNAs containing PTCs are normally degraded by the nonsense-mediated mRNA decay (NMD) system. However, PTCs located within 50–55 nucleotides of the last exon–exon junction are not recognized by NMD (NMD-irrelevant), and some PTC-containing mRNAs can escape from the NMD system (NMD-escape). We investigated protein expression from NMD-irrelevant and NMD-escape PTC-containing mRNAs by Western blotting and transfection assays. We demonstrated that transfection of NMD-irrelevant PTC-containing genomic DNA of <I>MARCKS</I> generates truncated protein. In contrast, NMD-escape PTC-containing versions of <I>hMSH3</I> and <I>TGFBR2</I> generate normal levels of mRNA, but do not generate detectable levels of protein. Transfection of NMD-escape mutant <I>TGFBR2</I> genomic DNA failed to generate expression of truncated proteins, whereas transfection of wild-type <I>TGFBR2</I> genomic DNA or mutant PTC-containing <I>TGFBR2</I> cDNA generated expression of wild-type protein and truncated protein, respectively. Our findings suggest a novel mechanism of gene expression regulation for PTC-containing mRNAs in which the deleterious transcripts are regulated either by NMD or translational repression.</P></▼1><▼2><P><B>Author Summary</B></P><P><B/></P><P>A class of mutations found in many cancers introduces aberrant termination signals during the synthesis of mRNA. In mammalian cells, abnormal mRNAs containing premature termination codons (PTCs) are normally degraded by a process called nonsense-mediated mRNA decay (NMD), thus avoiding potentially deleterious effects from abnormal protein production. However, some PTC-containing mRNAs are known to escape from NMD. By screening protein expression from genes with serious mutations in colon cancers, we confirmed that PTC-containing mRNAs of some genes escape from NMD. However, their abnormal proteins were not found in the tumor cells. To study the means by which these proteins were regulated, we transfected separate cell lines with NMD-escape mutant genomic DNA, wild-type genomic DNA, and mutant cDNA. We found that truncated proteins are not generated from the NMD-escape mutant genomic DNA, whereas wild-type protein and truncated protein were generated normally. These results indicate that the translation of PTC-containing mutant mRNAs is repressed in the cytoplasm.</P></▼2><▼3><P>A novel mechanism for regulating the products of nonsense mRNAs that contain premature termination codons involves repression at the level of translation.</P></▼3>
Effect of Preoperative Treatment for Hepatic Resection in Patient with HCC
( Tae Yun Lee ),( Dong Goo Kim ),( Bong Jun Kwak ),( Jae Hyun Han ),( Ho Joong Choi ),( Tae Ho Hong ),( Young Kyoung You ) 대한간학회 2018 춘·추계 학술대회 (KASL) Vol.2018 No.1
Aims: Hepatic resection is a cornerstone in the treatment of HCC patients. However, after resection, low resection rate and high recurrence rate are problematic. In liver transplantation, preoperative treatment has a good outcome, but it is doubtful whether resection shows the same result. Methods: From January 2005 to December 2015, 274 patients who underwent curative hepatic resection in our center were included. And then, they were divided into hepatic resection only (HRO) group (n=208, 75.9%) and preoperative treatment (PT) group (n=66, 24.1%). Preoperative treatment was TACE, and effect after treatment was analyzed by changes by mRECIST and tumor marker (AFP, PIVKA). Also, PT group was divided into responder (complete response/partial response in mRECIST or reduction of tumor marker) and non-responder (stable disease/progressive disease in mRECIST or increase of tumor marker). Then, we evaluated recurrence, the disease-free survival rate (DFS), the overall survival rate (OS), and various other factors based on the characteristics of patients and tumors according to two groups. Results: Of the 274 patients, the recurrence rate was 48.2% and related factors were tumor size, MVI, TNM stage, and preoperative treatment. 5-year DFS and OS rates were 42.6% and 69.8%. We found no statistically significant difference in the DFS (P=.397) and OS (P=.373) rates between HRO and PT group. Also, classification by Milan criteria did not affect DFS or OS. HRO and responder in PT group showed no difference between DFS and OS, but non-responder in PT group showed significantly worse in both DFS and OS. (DFS, P=.029, OS, P=.003 in mRECIST, DFS, P=.079, OS, P=.002 in AFP) Conclusions: Hepatic resection is still an effective tool for initial treatment of HCC. Preoperative treatment did not affect the outcome after resection. If there was no response after preoperative treatment, resection should be considered carefully since postoperative results were statistically poor. To further ensure this result, further studies will be needed to collect more cases.
NRF2 Blockade Suppresses Colon Tumor Angiogenesis by Inhibiting Hypoxia-Induced Activation of HIF-1α
( Tae Hyoung Kim ),( Eu Gene Hur ),( Su Jin Kang ),( Jung Ae Kim ),( Dinesh Thapa ),( You Mie Lee ),( Sae Kwang Ku ),( Yun Jun Jung ),( Mi Kyoung Kwak ) 영남대학교 약품개발연구소 2011 영남대학교 약품개발연구소 연구업적집 Vol.21 No.-
( Tae Ho Hong ),( Young Chul Youn ),( Young Kyoung You ),( Dong Goo Kim ) 대한내과학회 2011 대한내과학회지 Vol.81 No.5
Purpose: The aim of this report was to describe a new reconstructive technique of pancreaticogastrostomy and to also discuss this procedure`s effectiveness for reducing the incidence of postoperative complications. Methods: We retrospectively analyzed early surgical outcomes in 21 consecutive patients who underwent this novel pancreaticogastrostomy after pancreaticoduodenectomy. Pancreaticogastrostomy was completed with 2 transpancreatic sutures with buttresses on both the upper and lower edges of the implanted pancreas through the retracted anterior gastrotomy. Results: Operative mortality was zero and morbidity was 23.8%. A significant pancreatic fistula occurred in 1 patient (4.7%; grade B). Conclusion: This technique is very easy to perform, less traumatic to the pancreatic stump, can be performed through a mini-laparotomy due to good vision and straight sutures, and it is secure owing to anchoring of the invaginated pancreatic stump to the stomach`s posterior wall with buttresses. The results of this pilot study indicate that the technique may provide a favorable outcome and could be an alternative method of pancreatoenteric anastomosis. However, to determine its superiority over the conventional procedures, this operative technique should be evaluated more comprehensively in a larger series.