http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Effect of reducing agents on the synthesis of anisotropic gold nanoparticles
Yoo Sunghoon,남동환,Singh Thangjam Ibomcha,Leem Gyu,이승현 나노기술연구협의회 2022 Nano Convergence Vol.9 No.5
The seed-mediated method is a general procedure for the synthesis of gold nanorods (Au NRs), and reducing agents such as ascorbic acid (AA) and hydroquinone (HQ) are widely used for the growth process. Further, they are mild reducing agents; however, when AA is used, controlling the size of Au NRs with a higher aspect ratio (localized surface plasmon resonance (LSPR) peak, λ Lmax > 900 nm) is challenging because it results in a faster growth rate of Au NRs. In contrast, when HQ is used, Au NRs with a higher aspect ratio can be synthesized as it slows down the growth rate of the Au NRs and greatly enhanced the λ Lmax . However, the increase in λ Lmax is still needs not satisfactory due to the limited enhancement in the aspect ratio of Au NRs due to utilization of single reducing agent. The growth kinetics of the Au NRs can be modulated by controlling the reducing power of the reducing agents. In such scenario, judicious use of two reducing agents such as AA and HQ simultaneously can help us to design Au NRs of higher aspect ratio in a controlled manner due to the optimum growth rate resulting from the combined effect of both the reducing agents. In this study, we investigated the effect of the two reducing agents by controlling the volume ratios. When the growth solution contains both the reducing agents, the growth of Au NRs is first initiated by the fast reduction of Au 3+ to Au + due to stronger reducing power of the AA and when the AA in the growth solution is completely utilized, further growth of the Au NRs continues as a result of the HQ thereby resulting to high aspect ratio Au NRs. Consequently, the LSPR peak (λ Lmax > 1275 nm) can be tuned by controlling the volume ratios of the reducing agents.
( Yoo-na Kim ),( Yong Jae Lee ),( Young Shin Chung ),( Jung-yun Lee ),( Eun Ji Nam ),( Sang Wun Kim ),( Sunghoon Kim ),( Young Tae Kim ) 대한산부인과학회 2018 대한산부인과학회 학술대회 Vol.104 No.-
Objective: The aim of our study was to evaluate efficacy, tolerability, and toxicity of dose-dense weekly paclitaxel plus three weekly carboplatin (ddPC) as neoadjuvant chemotherapy (NAC) compared with standard three weekly paclitaxel and carboplatin regimen for advanced ovarian cancer. Methods: We conducted a retrospective study of patients diagnosed with stage IIIc and IV ovarian cancer who received at least one cycle of ddPC or standard chemotherapy followed by interval debulking surgery (IDS) between December 2015 and January 2018. Patient characteristics, response from NAC, outcomes of interval debulking surgery (IDS), and pathologic response were compared between two groups. Results: A total of 21 patients in the ddPC group and 50 patients in the standard group were analyzed. A median of 3 cycles of NAC were given in each group. Rates of hematologic toxicity were significantly higher in the ddPC group, compared to the standard group: anemia (19.0% vs. 4.00%, p = 0.003), neutropenia (95.2% vs. 38.8%, p = 0.002), and grade IV lymphopenia (19.0% vs. 2.00%, p = 0.025). Patients in the ddPC group were more likely to undergo dose reduction during NAC (28.6% in ddPC group vs. 4.00% in standard group, p = 0.007), yet the rates of treatment delay beyond 1 week were not different (p = 0.059). The two groups were comparable in terms of clinical response; proportional decrease in CA 125 (p = 0.936), R0 rate after IDS (p = 0.370), and chemotherapy response score (p = 1.000). Progression free survival at 2 years was 20.8% in ddPC group and 37.9% in the standard group (p = 0.782). Conclusion: Clinical outcomes of ddPC were not different from those who received the standard chemotherapy in advanced-stage ovarian cancer undergoing NAC. While the ddPC was tolerable, the increase in grade III and IV hematologic toxicity, resulting in G-CSF administration and transfusion, necessitates refinements in patient selection and ways to utilize the change in hematological milieu using combination therapy for improved outcome.
( Yoo-na Kim ),( Yeeun Shim ),( Yong Jae Lee ),( Sang Wun Kim ),( Saeam Shin ),( Sunghoon Kim ),( Jong Rak Choi ),( Seung-tae Lee ),( Jung-yun Lee ) 대한산부인과학회 2022 대한산부인과학회 학술대회 Vol.108 No.-
Objective: Understanding and appropriately tailoring therapy for ovarian cancer patients who progress on PARP inhibitor (PARPi) is a pressing agenda. Our objective was to investigate the patient-specific resistance mechanism and its implication on post-progression therapy via serially collected ctDNA. Methods: Patients with BRCA mutated ovarian cancer receiving PARPi were prospectively enrolled since January 2018. Whole blood samples were collected every 3 months. Extracted cell-free DNA were target enriched with TMB500 panel, sequenced with Novaseq 6000 system (Illumina), and analyzed using PiSeq (Dxome). Clinical information, including progression-free survival (PFS) to PARPi and to post-progression therapy (PFS2-PFS1) and overall survival (OS) post-progression, were collected. Results: Serial samples from 54 patients were analyzed. Analysis of pre-PARPi samples showed an improved PFS to PARPi in patients without mutation in resistance mechanism-associated genes. BRCA reversion and hypomorphism were identified in 3 and 1 patients, respectively. Matched samples from 29 patients showed an increased in TMB and a spectrum of post-specific, acquired mutations. These acquired mutations highlighted non-exclusive resistance mechanisms, including HR restoration (28%), replication fork stability (34%), and G1/S defect (i.e., ATM, CHEK2, and TP53, 55%), which were potential targets for ATR inhibitor. Among patients with matched samples, post-progression therapy information were available in 22 patients, including 7 patients receiving PARPi re-treatment. Patients with acquired mutations in HR restoration-associated genes showed poor OS post-progression. Conversely, those without any acquired mutation or with mutations involving single resistance mechanism showed a trend of favorable response to subsequent platinum-based therapy and PARPi re-treatment. Conclusion: Serial ctDNA may help predict response to PARPi as well as provide important prognostic and predictive clues for post-progression therapy in ovarian cancer.
( Yoo-na Kim ),( Yun Soo Chung ),( Junsik Park ),( Yong Jae Lee ),( Jung-yun Lee ),( Eun Ji Nam ),( Sang Wun Kim ),( Sunghoon Kim ),( Young Tae Kim ) 대한산부인과학회 2022 대한산부인과학회 학술대회 Vol.108 No.-
Objective: HER2 targeted drugs are increasingly introduced in non-breast cancers, yet studies on HER2 expression in ovarian cancer patients is lacking. Therefore, we studied HER2 receptor status and its dynamic change in ovarian cancer patients, a subset of whom also underwent next-generation sequencing (NGS). Methods: Ovarian cancer patients who underwent HER2 testing between January 2015 and May 2021 at Yonsei Cancer Hospital were identified. Clinical information, including histology, germline BRCA status, and immunohistochemistry (IHC) profile were noted. For patients receiving multiple time-lagged biopsies, each anatomical location, timing, and HER2 expression were counted. Results: A total of 200 patients with ovarian cancer, mostly advanced stage and high-grade serious histology, were identified. HER2 expressions of 2+ and 3+ were found in 28% and 6% respectively. A total of 33 patients (16.5%) received targeted therapy including Herceptin in 16 patients. With respect to histology, HER2 3+ rate was 23% in mucinous, 11% in endometrioid, 9% in clear cell, and 5% in high-grade serous type. HER2 3+ was exclusively identified in BRCA wildtype, mismatch repair proficient, or PD-L1 low expressing patients. Genomic analysis showed that in HER2 2+ or 3+ patients the TP53 mutation rate was lower and other mutations such as ARID1A, KRAS, PIK3CA were relatively more common, compared to HER2 0 or 1+ patients. CNV analysis showed that 4 out of 5 patients with HER2 3+ showed ERBB2 amplification on NGS. With respect to anatomical distribution, HER2+ and 3+ were frequently identified in ovary and breast biopsy specimen. Out of 20 patients with multiple time-lagged biopsy, 9 patients showed an increase in HER2 expression in the later biopsy sample. Conclusion: Ovarian cancer patients with HER2 overexpression show a distinct histological, IHC, and genomic profile. HER2 targeting agent may serve as a potential option for BRCA wildtype patients, especially in the later lines of treatment.
( Yoo-na Kim ),( Kyung Jin Eoh ),( Jung-yun Lee ),( Eun Ji Nam ),( Sunghoon Kim ),( Sang Wun Kim ),( Young Tae Kim ) 대한산부인과학회 2018 Obstetrics & Gynecology Science Vol.61 No.4
Objective Intravenous leiomyomatosis (IVL) and benign metastasizing leiomyoma (BML) are uncommon variants of benign uterine leiomyomas with extrauterine manifestations. Categorizing the extent of disease allows clinicians to delineate the clinical spectrum and the level of sophistication for complete surgical resection. Methods Twelve patients with IVL and BML were reviewed. They were divided into early versus late stage disease groups, and initial manifestation, clinical characteristics, laboratory values, surgical pathology, and follow up data were summarized. Results Patients were mostly pre- or peri-menopausal and parous. Patients with late stage disease were more likely to present with cardiac symptoms or abnormal findings on chest X-ray, whereas those with early stage disease presented with classical leiomyoma symptoms including heavy menstrual bleeding, increased myoma size, or lower abdominal discomfort. Tumor marker levels were within normal ranges. A trend of higher neutrophil to leukocyte ratio was observed in the late versus the early stage group (10.4 vs. 1.51, P=0.07); the platelet leukocyte ratio was statistically higher in patients with late stage IVL (0.23 vs. 0.13, P=0.04). The overall recurrence rate was 25%. No recurrence was observed in stage I or stage III IVL groups, while 50% of the stage II IVL group showed recurrence in the pelvic cavity. Conclusion IVL and BML are benign myoma variants with paradoxically metastatic clinical presentation. Careful inquiry of systemic symptoms, the presence of underlying systemic inflammation, and a high index of suspicion are required for preoperative diagnosis. Furthermore, a multidisciplinary approach is necessary to improve outcomes of surgical resection.
A Multicenter Study of Pertussis Infection in Adults with Coughing in Korea: PCR-Based Study
Park, Sunghoon,Lee, Myung-Gu,Lee, Kwan Ho,Park, Yong Bum,Yoo, Kwang Ha,Park, Jeong-Woong,Kim, Changhwan,Lee, Yong Chul,Park, Jae Seuk,Kwon, Yong Soo,Seo, Ki-Hyun,Kim, Hui Jung,Kwak, Seung Min,Kim, Ju- The Korean Academy of Tuberculosis and Respiratory 2012 Tuberculosis and Respiratory Diseases Vol.73 No.5
Background: Limited data on the incidence and clinical characteristics of adult pertussis infections are available in Korea. Methods: Thirty-one hospitals and the Korean Centers for Disease Control and Prevention collaborated to investigate the incidence and clinical characteristics of pertussis infections among adults with a bothersome cough in non-outbreak, ordinary outpatient settings. Nasopharyngeal aspirates or nasopharyngeal swabs were collected for polymerase chain reaction (PCR) and culture tests. Results: The study enrolled 934 patients between September 2009 and April 2011. Five patients were diagnosed as confirmed cases, satisfying both clinical and laboratory criteria (five positive PCR and one concurrent positive culture). Among 607 patients with cough duration of at least 2 weeks, 504 satisfied the clinical criteria of the US Centers for Disease Control and Prevention (i.e., probable case). The clinical pertussis cases (i.e., both probable and confirmed cases) had a wide age distribution ($45.7{\pm}15.5$ years) and cough duration (median, 30 days; interquartile range, 18.0~50.0 days). In addition, sputum, rhinorrhea, and myalgia were less common and dyspnea was more common in the clinical cases, compared to the others (p=0.037, p=0.006, p=0.005, and p=0.030, respectively). Conclusion: The positive rate of pertussis infection may be low in non-outbreak, ordinary clinical settings if a PCR-based method is used. However, further prospective, well-designed, multicenter studies are needed.
정성훈(Sunghoon Jeong),류성희(Sung Hee Yoo),정대현(Dae Hyeon Joung),이희범(Heui Bom Lee) 한국자동차공학회 2012 한국자동차공학회 학술대회 및 전시회 Vol.2012 No.11
The quenched and tempered steel is usually treated by heat treatment. But micro-alloyed steel including alloying elements such as vanadium, boron and so on is applied without overall heat treatment. The surface of crankshaft made with micro-alloyed steel is locally processed by induction hardening. The process can cause a crack on grinded surfaces when residual tensile stress is higher than strength of the material. Therefore crack inspection is required. Various inspection methods such as magnetic testing and eddy current testing have been used for detecting surface defects of shaft in automobile engine and transmission. Magnetic testing is to see fluorescent lines by condensed magnetic particles on defects and can have an error because of worker’s subjective judgment. Eddy current testing is difficult to be flexible because it should have many sensors to detect surface defects. Also, it has limitation in detection ability because the higher sensor sensitivity is the more noise is included. The eddy current sensor can detect cracks above a depth of 0.1mm. In this paper, it is investigated that vision inspection method is valid in ability of detection, classification, measurement of surface defects such as crack, contamination, scratch, and pores.