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Structural considerations in friction welding of hybrid Al_2O_3-reinforced aluminum composites

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Transactions of Nonferrous Metals Society of China 2011年第A01期21卷 42-46页

作者： In-Duck PARK Choon-Tae LEE Hyun-soo kim Woo-Jin CHOI Myung-Chang KANG Busan Metropolitan City Hall Fundamental Industries Division 2001 Jungang-ro Yeonje-gu Busan 611-735 Korea Department of Automotive & Mechanical Engineering Silla University Research & Development Center Sam-Ho precision 1256-1 Daejeo2-dong Gangseo-gu Busan 618-807 Korea National Core Research Center for Hybrid Materials Solution Pusan National University

Comparative studies on the relationship between the welding parameters and joining efficiency in the friction welding of hybrid Al203-reinforced aluminum composites were conducted. Metal matrix composites （MMCs） with 37% （volume fraction） aluminum particle were joined by friction welding. The results show that the effects of the rotation speed on the reduction rate of particle size are greater than those of the upset pressure, and the area of the MMC weld zone decreases as the joining efficiency increases, while it is considered that the joining efficiency does not increase as the reduction rate of particle size decreases. During the macro-examination of the bonding interlace, a gray discolored region was observed on the bonding interface, and the center of the region was dark gray. After the micro-examination of the bonding interface, base metal made some second particulate formed by condensed alumina particulate but discoloration part distributed minute alumina particulate without second particulate. Consequently, it was also observed that rotational speed of 3 000 r/min and upset pressure of 63.6 MPa showed a very ***.

关键词： friction welding hybrid aluminum composite bonding interface joining efficiency metal matrix composite

Emerging role of ^(18)F-fluorodeoxyglucose positron emission tomography for guiding management of hepatocellular carcinoma

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World Journal of Gastroenterology 2019年第11期25卷 1289-1306页

作者： Sang Mi Lee Hong soo kim Sangheun Lee Jeong Won Lee Department of Nuclear Medicine Soonchunhyang University Cheonan Hospital Department of Internal Medicine Soonchunhyang University Cheonan Hospital Division of Hepatology Department of Internal medicineCatholic Kwandong University College of MedicineInternational St.Mary’s Hospital Institute for Health and Life Science Catholic Kwandong University College of MedicineInternational St.Mary’s Hospital Department of Nuclear Medicine Catholic Kwandong University College of MedicineInternational St.Mary’s Hospital

Hepatocellular carcinoma(HCC) is one of major causes of cancer mortality worldwide. For decades, ^(18)F-fluorodeoxyglucose(FDG) positron emission tomography(PET) has been widely used for staging, predicting prognosis, and detecting cancer recurrence in various types of malignant diseases. Due to low sensitivity of FDG PET for detecting intrahepatic HCC lesions, the clinical value of FDG PET in HCC patients has been limited. However, recent studies with diverse analytic methods have shown that FDG PET has promising role in aiding management of HCC patients. In this review, we will discuss the clinical role of FDG PET for staging, predicting prognosis, and evaluating treatment response in HCC. Further, we will focus on recent clinical studies regarding implication of volumetric FDG PET parameters, the significance of FDG uptake in HCC for selecting treatment and predicting treatment response, and the use of radiomics of FDG PET in HCC.

关键词： Hepatocellular carcinoma Fluorodeoxyglucose F18 Positron emission tomography Staging Prognosis

Enhanced intestinal lymphatic absorption of saquinavir through supersaturated self-microemulsifying drug delivery systems

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Asian Journal of Pharmaceutical Sciences 2020年第3期15卷 336-346页

作者： Kanghee Jo Hyeongmin kim Prakash Khadka Taejun Jang soo Jin kim Seong-Ha Hwang Jaehwi Lee College of Pharmacy Chung-Ang UniversitySeoul 06974Republic of Korea

The therapeutic potential of saquinavir, a specific inhibitor of human immunodeficiency virus(HIV)-1 and HIV-2 protease enzymes, has been largely limited because of a low solubility and consequnt low bioavailability. Thus, we aimed to design a supersaturated selfmicroemulsifying drug delivery system(S-SMEDDS) that can maintain a high concentration of saquinavir in gastro-intestinal fluid thorugh inhibiting the drug precipitation to enhance the lymphatic transport of saquinavir and to increase the bioavailability of saquinavir considerably. Solubilizing capacity of different oils, surfactants, and cosurfactants for saquinavir was evaluated to select optimal ingredients for preparation of *** the construction of pseudo-ternary phase diagram, SMEDDS formulations were established. A polymer as a precipitation inhibitor was selected based on its viscosity and drug precipitation inhibiting capacity. The S-SMEDDS and SMEDDS designed were administered at an equal dose to rats. At predetermined time points, levels of saquinavir in lymph collected from the rats were assessed. SMEDDS prepared presented a proper selfmicroemulsification efficiency and dispersion stability. The S-SMEDDS fabricated using the SMEDDS and hydroxypropyl methyl cellulose 2910 as a precipitation inhibitor exhibited a signficantly enhanced solubilizing capacity for saquinavir. The drug concentration in a simulated intestinal fluid evaluated with the S-SMEDDS was also maintained at higher levels for prolonged time than that examined with the SMEDDS. The S-SMEDDS showed a considerably enhanced lymphatic absoprtion of saquinavir in rats compared to the ***, the S-SMEDDS would be usefully exploited to enhance the lymphatic absorption of hydrophobic drugs that need to be targeted to the lymphatic system.

关键词： Lymphatic drug delivery Self-microemulsifying drug delivery system Saquinavir Precipitation inhibitor Supersaturation Lipid-based formulation

Effect of Post-Rolling after ECAP on Superplastic Behavior of Commercial Al-Mg Alloy

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Journal of Rare Earths 2004年第z2期22卷 53-56页

作者： Dong Hyuk Shin Byung Du Ahn Hyun soo Woo Kyeom kim Kyung-Tae Park Department of Metallurgy and Materials Science Hanyang UniversityAnsan 425-791Korea Department of Metallurgy and Materials ScienceHanyang UniversityAnsan 425-791Korea Department of Metallurgy and Materials ScienceHanyang UniversityAnsan 425-791Korea Department of Metallurgy and Materials ScienceHanyang UniversityAnsan 425-791Korea Division of Advanced Materials Science & EngineeringHanbat National UniversityTaejon 305-719Korea

A commercial Al-Mg alloy was subjected to equal channel angular pressing of 4 passes with and without postrolling, and the effects of post-rolling on the deformation characteristics of the alloy at 723 K were examined. Post-rolling was found to influence the deformation behavior significantly. The deformation behavior of the alloy processed only by equal channel angular pressing was characterized by (a) localized deformation indicated by severe surface prominence and depression, (b) the strain rate sensitivity of 0.33, and (c) moderate high strain rate superplastic elongations. By contrast, that of the alloy processed by equal channel angular pressing and post-rolling (70 % thickness reduction) was manifested by (a) uniform deformation associated with grain boundary sliding throughout the sample, (b) a sigmoidal behavior showing the strain rate sensitivity of 0.45 at the intermediate strain rates in the logarithmic stress-strain rate curve, and (c) very large high strain rate superplastic elongations.

关键词： high superplasticity equal channel angular pressing rolling deformation mechanisms rare earths

The effects of androgen on penile reflex, erectile response to electrical stimulation and penile NOS activity in the rat

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Asian Journal of Andrology 1999年第4期1卷 169-174页

作者： Seong Il Seo soo Woong kim Jae-Seung Paick Department of Urology Seoul National University College of Medicine Seoul 110-744 KoreaDepartment of Urology Seoul National University College of Medicine Seoul 110-744 KoreaDepartment of Urology Seoul National University College of Medicine Seoul 110-744 Korea

Aim: To investigate the effects of androgen on penile erection through the reflex arc and penile corpus cavernosum,and study the respective roles of testosterone (T) and dihydrotestosterone (DHT) in penile erection in rats. Methods:Male Sprague-Dawley rats were castrated and implanted with silastic brand silicone tube containing T or DHT, with orwithout daily injections of a 5α-reductase inhibitor, MK-434. The penile reflex, erectile response to electrical stimula-tion (ES) of the cavernous nerves and penile nitric-oxide synthase (NOS) activity were observed under varying andro-genic status. Results: Penile reflex erection in the rat was, on the whole, related to serum T levels though the numberof glans engorgements was not. The number of cups and flips was significantly decreased by castration, and restoredto the control level by T supplementation. Erectile response to ES and NOS activity in penile tissue was also related toserum T level. T administered together with a 5α-reductase inhibitor no longer restored the number of reflex erection,erectile responses to ES and NOS activity in the corpus cavernosum. Conclusion: Androgen influenced the penile re-flex arc, corpus cavernosum, and the perineal striated muscles. In reflex erection, erectile response to ES and penileNOS activity in the rat, T seems to be first converted to DHT, the more active androgen modality. (Asian J Androl1999 Dec; 1: 169-174)

关键词： androgens penile erection reflex electric stimulation nitric-oxide synthase

Effects of granulation process variables on the physical properties of dosage forms by combination of experimental design and principal component analysis

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Asian Journal of Pharmaceutical Sciences 2019年第3期14卷 287-304页

作者： Prakash Thapa Du Hyung Choi Min soo kim Seong Hoon Jeong College of Pharmacy Dongguk UniversityGyeonggi10326Republic of Korea Department of Pharmaceutical Engineering Inje UniversityGyeongnam50834Republic of Korea College of Pharmacy Pusan National UniversityBusan46241Republic of Korea

The current study was to understand how process variables of high shear wet granulations affect physical properties of granules and tablets. The knowledge gained was intended to be used for Quality-by-Design based process design and optimization. The variables were selected based on the risk assessment as impeller speed, liquid addition rate, and wet massing time. Formulation compositions were kept constant to minimize their influence on granules properties. Multiple linear regression models were built providing understanding of the impact of each variable on granule hardness, Carr’s index, tablet tensile strength, surface mean diameter of granules, and compression behavior. The experimental results showed that the impact of impeller speed was more dominant compared to wet massing time and water addition rate. The results also revealed that quality of granules and tablets could be optimized by adjusting specific process variables(impeller speed 1193 rpm, water spray rate 3.7 ml/min, and wet massing time 2.84 min). Overall desirability was 0.84 suggesting that the response values were closer to the target one. The SEM image of granules showed that spherical and smooth granules produced at higher impeller speed, whereas rough and irregular shape granules at lower speed. Moreover, multivariate data analysis demonstrated that impeller speed and massing time had strong correlation with the granule and tablet properties. In overall, the combined experimental design and principal component analysis approach allowed to better understand the correlation between process variables and granules and tablet attributes.

关键词： Experimental design Principal component analysis High shear granulation Process parameter

A simple, flexible and high-throughput cloning system for plant genome editing via CRISPR-Cas system

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Journal of Integrative Plant Biology 2016年第8期58卷 705-712页

作者： Hyeran kim Sang-Tae kim Jahee Ryu Min Kyung Choi Jiyeon Kweon Beum-Chang Kang Hyo-Min Ahn Suji Bae Jungeun kim Jin-soo kim Sang-Gyu kim Center for Genome Engineering Institute for Basic Science Department of Chemistry Seoul National University

CRISPR-Cas9 system is now widely used to edit a target genome in animals and plants. Cas9 protein derived from Streptococcus pyogenes（Sp Cas9） cleaves double-stranded DNA targeted by a chimeric single-guide RNA（sg RNA）. For plant genome editing, Agrobacterium-mediated T-DNA transformation has been broadly used to express Cas9 proteins and sg RNAs under the control of Ca MV 35 S and U6/U3 promoter, respectively. We here developed a simple and high-throughput binary vector system to clone a 19 20 bp of sg RNA, which binds to the reverse complement of a target locus, in a large T-DNA binary vector containing an Sp Cas9 expressing cassette. Twostep cloning procedures：（1） annealing two target-specific oligonucleotides with overhangs specific to the Aar I restriction enzyme site of the binary vector; and（2） ligating the annealed oligonucleotides into the two Aar I sites of the vector, facilitate the high-throughput production of the positive clones. In addition, Cas9-coding sequence and U6/U3 promoter can be easily exchanged via the GatewayTMsystem and unique Eco RI/Xho I sites on the vector, respectively. We examined the mutation ratio and patterns when we transformed these constructs into Arabidopsis thaliana and a wild tobacco, Nicotiana attenuata. Our vector system will be useful to generate targeted large-scale knock-out lines of model as well as non-model plant.

关键词： Aar I-mediated sg RNA cloning CRISPR-Cas9 T-DNA binary vector Exchangeable U6/U3 promoter Gateway compatible Cas9 cloning

Characteristics of nonvariceal upper gastrointestinal hemorrhage in patients with chronic kidney disease

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World Journal of Gastroenterology 2013年第43期19卷 7719-7725页

作者： Chang Seok Bang Yong Seop Lee Yun Hyeong Lee Hotaik Sung Hong Jun Park Hyun soo kim Jin Bong kim Gwang Ho Baik Yeon soo kim Jai Hoon Yoon Dong Joon kim Ki Tae Suk Department of Internal Medicine Hallym University College of MedicineChuncheon 200-704South Korea Department of Biology Stanford UniversityStanfordCA 94305United States Department of Internal Medicine Yonsei University Wonju College of MedicineWonju 220-786South Korea

AIM:To evaluate the clinical characteristics of nonvariceal upper gastrointestinal hemorrhage(NGIH)in patients with chronic kidney disease(CKD).METHODS:From 2003 to 2010,a total of 72 CKD patients(male n=52,72.2%;female n=20,27.8%)who had undergone endoscopic treatments for NGIH were retrospectively *** findings,endoscopic features,prognosis,rebleeding risk factors,and mortality-related factors were *** characteristics of the patients and rebleeding-related data were recorded for the following variables:gender,age,alcohol use and smoking history,past hemorrhage history,endoscopic findings(the cause,location,and size of the hemorrhage and the hemorrhagic state),therapeutic options for endoscopy,endoscopist experience,clinical outcomes,and ***:The average size of the hemorrhagic site was 13.7±10.2 mm,and the most common hemorrhagic site in the stomach was the antrum(n=21,43.8%).The most frequent method of hemostasis was combination therapy(n=32,44.4%).The incidence of rebleeding was 37.5%(n=27),and 16.7%(n=12)of patients expired due to *** a multivariate analysis of the risk factors for rebleeding,alcoholism(OR=11.19,P=0.02),the experience of endoscopists(OR=0.56,P=0.03),and combination endoscopic therapy(OR=0.06,P=0.01)compared with monotherapy were significantly related to rebleeding after endoscopic *** a risk analysis of mortality after endoscopic therapy,only rebleeding was related to mortality(OR=7.1,P=0.02).CONCLUSION:Intensive combined endoscopic treatments by experienced endoscopists are necessary for the treatment of NGIH in patients with CKD,especially when a patient is an alcoholic.

关键词： Chronic kidney diseases Gastrointestinal hemorrhage Endoscopy Peptic ulcer Alcoholics

A case of ascending colon variceal bleeding treated with venous coil embolization

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World Journal of Gastroenterology 2013年第2期19卷 311-315页

作者： Bong Suk Ko Woo Tae kim Su Sun Chang Eun Hye kim Seung Woo Lee Won Seok Park Yeon soo kim soon Woo Nam Dong soo Lee Ji Chang kim Sang Bum Kang Department of Internal Medicine College of MedicineThe Catholic University of KoreaDaejeon St.Mary's HospitalDaejeon 301-723South Korea Department of Radiology College of MedicineThe Catholic University of KoreaDaejeon St.Mary's HospitalDaejeon 301-723South Korea

A 38-year-old female with a history of alcoholic liver cirrhosis visited our hospital with a massive *** esophagogastroduodenoscopy did not demonstrate any bleeding source,and a colonoscopy showed a massive hemorrhage in the ascending colon but without an obvious *** source of the bleeding could not be found with a mesenteric artery *** performed an enhanced abdominal computed tomography,which revealed a distal ascending colonic varix,and assumed that the varix was the source of the *** performed a venous coil embolization and histoacryl injection to obliterate the colon *** intervention appeared to be successful because the vital signs and hemoglobin laboratory data remained stable and because the hematochezia was no longer *** report here on a rare case of colonic variceal bleeding that was treated with venous coil embolization.

关键词： Colon ascending Varicose veins Liver cirrhosis Therapeutic embolization