Enzymatic Esterification under High-pressure CO2 Conditions for in situ Recovery of Butyric Acid from Anaerobic Fermenters

Jaesung Chun,상병인 한국생물공학회 2020 Biotechnology and Bioprocess Engineering Vol.25 No.4

Butyric acid, a short chain carboxylic acid with diverse usages, is produced by Clostridia fermentation. In the industrial scale production of butyric acid, its separation and recovery from fermentation broth requires energyintensive processes. To reduce the product recovery costs, it is necessary to convert butyric acid into a chemical with a much higher partition coefficient in the hydrophobic extractants than butyric acid. Butyl butyrate, with an excellent partition coefficient to tetradecane, can be produced by the enzymatic conversion of butyric acid via esterification. Moreover, butyl butyrate can be used as a valuable fuel source and additive in the food, cosmetic, and pharmaceutical industries. Novozyme 435, Candida antarctica lipase B immobilized on acrylic resin, and tetradecane were used as the enzyme and extractant, respectively. A high-pressure CO2-facilitated reactor was used to temporarily drop the pH of the fermentation broth so that the enzymatic reaction could be activated. The in situ removal of butyric acid and simultaneous production of butyl butyrate were processed continuously during fermentation. To optimize the enzymatic reaction, it was necessary to maintain a temperature of 40°C at 50 bar and an optimal molar ratio of substrate. In the extractive fermentation, 11.6 g/L butyl butyrate was produced with a productivity of 0.77 g/L/h from butyrate produced through fermentation. This process is expected to be able to extract carboxylic acids with more diverse carbon lengths in ester form.

Extraction of fermentative butyric acid using high pressure CO₂

Jaesung CHUN,Byoung Seung JEON,Byung-Chun KIM,Byoung-In SANG 한국생물공학회 2013 한국생물공학회 학술대회 Vol.2013 No.10

Metabolic comorbidities and medical institution utilization among breast cancer survivors: a national population-based study

( Jaesung Heo ),( Mison Chun ),( Young-taek Oh ),( O Kyu Noh ),( Logyoung Kim ) 대한내과학회 2020 The Korean Journal of Internal Medicine Vol.35 No.2

Background/Aims: We investigated metabolic comorbidity status and patterns of medical institution utilization among breast cancer survivors using medical claims data from the Health Insurance Review and Assessment Service (HIRA). Methods: Using claims data obtained from the HIRA, we selected breast cancer survivors between 2010 and 2015. Descriptive statistics were calculated to determine the frequency of metabolic comorbidities, as well as to analyze patterns of medical institution utilization in accordance with disease status. Results: A total of 89,953 breast cancer survivors were identified. Among these, 12,364 (13.7%) had hypercholesterolemia, 20,754 (23.1%) had hypertension (HTN), and 11,102 (12.3%) had diabetes mellitus (DM). In particular, more than half of breast cancer survivors older than 60 years had HTN, and other diseases sharply increased beginning at age 50 years. For HTN, a total of 531,292 claims were submitted; more than 80% (n = 473,737) were from primary medical institutions, whereas only 2.4% (n = 12,551) were from tertiary medical institutions. The number of claims submitted for DM was 231,526; those from primary medical institutions accounted for 68.5% (n = 158,566), whereas claims from tertiary medical institutions accounted for 12.0% (n = 27,693). In subgroup analyses, the utilization of secondary and tertiary medical institutions was higher among patients with severe diseases and those diagnosed following their breast cancer diagnosis. Conclusions: More than 10% of breast cancer survivors were diagnosed with a metabolic comorbidity. Through analysis of medical institution utilization patterns, we ascertained that a communication system linking secondary and tertiary medical institutions with primary medical institutions is needed.

Sepsis diagnosis and treatment using nanomaterials

Jaesung Lim,Yun Young Lee,Young Bin Choy,Wooram Park,Chun Gwon Park 대한의용생체공학회 2021 Biomedical Engineering Letters (BMEL) Vol.11 No.3

Sepsis is a life-threatening reaction that occurs when the body’s severe response to an infection damages the host’s owntissues. Sepsis has been globally recognized as a fatal disease. Rapid treatment of sepsis requires prompt identifi cation,administering antibiotics, careful hemodynamic support, and treating the cause of the infection. Clinical outcomes of sepsisdepend on early diagnosis and appropriate treatment. Unfortunately, current sepsis diagnosis and treatment, such as polymerasechain reaction-based assay, blood culture assay, and antibiotic therapy, are ineff ective; consequently, sepsis-relatedmortality remains high and increases antimicrobial resistance. To overcome this challenge, nanotechnology, which involvesengineering at a nanoscale, is used for diagnosing and treating sepsis. Preclinical models have shown protective eff ects andpotential utility in managing septic shock. Furthermore, nanotechnology treatments based on diverse materials result inthe eff ective treatment of sepsis, improving the survival rate. In this review, we present an overview of the recent researchadvancements in nanotechnology to diagnose and treat sepsis with a brief introduction to sepsis.

Efficient Activation of Dendritic Cells with Immuno-modulating Functional Nanoparticles in Hydrogel

Jaesung LIM,Hee Seung SEO,Jun-Hyeok HAN,Wooram PARK,Chun Gwon PARK 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.4

Modulation of the immunosuppressive tumor microenvironment (TME) is crucial for effective tumor treatment. Herein, we demonstrate an immune-modulating hydrogel containing functional nanoparticles. These nanoparticles were synthesized by a heat-up method and coated with CpG oligonucleotide capable of activating the dendritic cells. When the CpG-coated nanoparticles were treated to bone marrow-derived dendritic cells (BMDCs), it upregulated activation marker for DCs such as CD80, CD86, CD40, and MHC2 molecules, suggesting the nanoparticles-mediated maturation of BMDCs. For sustained and local delivery of the prepared CpG-coated nanoparticles to the tumor resection site, the functional nanoparticles were embedded in a hydrogel based on methacrylate-modified hyaluronic acid. Finally, the immune-modulating hydrogel was implanted in a fat pad after the surgical-resected breast tumor model in vivo. The implantation of the immune-modulating hydrogel could be able to effectively activate the DCs in the vicinity of the tumor resection site, resulting in the activation of cytotoxic T cells. We believe this strategy has great potential for effective prevention of tumor recurrence and metastasis.

CT-based quantitative evaluation of radiation-induced lung fibrosis: a study of interobserver and intraobserver variations

Jaesung Heo,Oyeon Cho,O Kyu Noh,Young-Taek Oh,Mison Chun,Mi-Hwa Kim,Hae-Jin Park 대한방사선종양학회 2014 Radiation Oncology Journal Vol.32 No.1

Purpose: The degree of radiation-induced lung fibrosis (RILF) can be measured quantitatively by fibrosis volume (VF) on chest computed tomography (CT) scan. The purpose of this study was to investigate the interobserver and intraobserver variability in CT-based measurement of VF. Materials and Methods: We selected 10 non-small cell lung cancer patients developed with RILF after postoperative radiation therapy (PORT) and delineated VF on the follow-up chest CT scanned at more than 6 months after radiotherapy. Three radiation oncologists independently delineated VF to investigate the interobserver variability. Three times of delineation of VF was performed by two radiation oncologists for the analysis of intraobserver variability. We analysed the concordance index (CI) and inter/intra-class correlation coefficient (ICC). Results: The median CI was 0.61 (range, 0.44 to 0.68) for interobserver variability and the median CIs for intraobserver variability were 0.69 (range, 0.65 to 0.79) and 0.61(range, 0.55 to 0.65) by two observers. The ICC for interobserver variability was 0.974 (p < 0.001) and ICCs for intraobserver variability were 0.996 (p < 0.001) and 0.991 (p < 0.001), respectively. Conclusion: CT-based measurement of VF with patients who received PORT was a highly consistent and reproducible quantitative method between and within observers.

Nodal tumor response according to the count of peripheral blood lymphocyte subpopulations during preoperative chemoradiotherapy in locally advanced rectal cancer

Jaesung Heo,Young Taek Oh,O Kyu Noh,Mison Chun,Jun Eun Park,Sung Ran Cho 대한방사선종양학회 2016 Radiation Oncology Journal Vol.34 No.4

Purpose: The objective of this prospective study was to evaluate the relationship between the circulating lymphocyte subpopulation counts during preoperative chemoradiotherapy (CRT) and tumor response in locally advanced rectal cancer. Materials and Methods: From August 2015 to June 2016, 10 patients treated with preoperative CRT followed by surgery were enrolled. Patients received conventional fractionated radiotherapy (50.4 Gy) with fluorouracil-based chemotherapy. Surgical resection was performed at 4 to 8 weeks after the completion of preoperative CRT. The absolute blood lymphocyte subpopulation was obtained prior to and after 4 weeks of CRT. We analyzed the association between a tumor response and change in the lymphocyte subpopulation during CRT. Results: Among 10 patients, 2 (20%) had evidence of pathologic complete response. In 8 patients with clinically node positive, 4 (50%) had nodal tumor response. All lymphocyte subpopulation counts at 4 weeks after CRT were significantly lower than those observed during pretreatment (p < 0.01). A high decrease in natural killer (NK) cell, count during CRT (baseline cell count − cell count at 4 weeks) was associated with node down staging (p = 0.034). Conclusion: Our results suggest that the change of lymphocyte subset to preoperative CRT may be a predictive factor for tumor response in rectal cancer.

Nodal tumor response according to the count of peripheral blood lymphocyte subpopulations during preoperative chemoradiotherapy in locally advanced rectal cancer

Heo, Jaesung,Oh, Young-Taek,Noh, O Kyu,Chun, Mison,Park, Jun-Eun,Cho, Sung-Ran The Korean Society for Radiation Oncology 2016 Radiation Oncology Journal Vol.34 No.4

Purpose: The objective of this prospective study was to evaluate the relationship between the circulating lymphocyte subpopulation counts during preoperative chemoradiotherapy (CRT) and tumor response in locally advanced rectal cancer. Materials and Methods: From August 2015 to June 2016, 10 patients treated with preoperative CRT followed by surgery were enrolled. Patients received conventional fractionated radiotherapy (50.4 Gy) with fluorouracil-based chemotherapy. Surgical resection was performed at 4 to 8 weeks after the completion of preoperative CRT. The absolute blood lymphocyte subpopulation was obtained prior to and after 4 weeks of CRT. We analyzed the association between a tumor response and change in the lymphocyte subpopulation during CRT. Results: Among 10 patients, 2 (20%) had evidence of pathologic complete response. In 8 patients with clinically node positive, 4 (50%) had nodal tumor response. All lymphocyte subpopulation counts at 4 weeks after CRT were significantly lower than those observed during pretreatment (p < 0.01). A high decrease in natural killer (NK) cell, count during CRT (baseline cell count - cell count at 4 weeks) was associated with node down staging (p = 0.034). Conclusion: Our results suggest that the change of lymphocyte subset to preoperative CRT may be a predictive factor for tumor response in rectal cancer.

IPSec - VPN에서의 네트워크 중복 문제 해결을 위한 IPSec 네트워크 별칭 기법

박재성(Jaesung Park),천준호(Junho Chun),전문석(Moon-Seog Jun) 한국정보과학회 2005 한국정보과학회 학술발표논문집 Vol.32 No.1

IPSec Tunnel Mode를 이용하여 보안 네트워크를 구축 시, 네트워크 구성이 중복된 경우에는 중복되지 않도록 재구성해야 하는 문제가 있다. 본 논문에서는 IPSec Tunnel Mode 통신을 하고자 하는 두 네트워크가 중복된 경우, IPSec 네트워크 별칭 기법을 통하여, 이전 네트워크의 구성을 변경하지 않고 통신할 수 있는 방안을 제시한다.

CT-based quantitative evaluation of radiation-induced lung fibrosis: a study of interobserver and intraobserver variations

Heo, Jaesung,Cho, Oyeon,Noh, O Kyu,O, Young-Taek,Chun, Mison,Kim, Mi-Hwa,Park, Hae-Jin The Korean Society for Radiation Oncology 2014 Radiation Oncology Journal Vol.32 No.1

Purpose: The degree of radiation-induced lung fibrosis (RILF) can be measured quantitatively by fibrosis volume (VF) on chest computed tomography (CT) scan. The purpose of this study was to investigate the interobserver and intraobserver variability in CT-based measurement of VF. Materials and Methods: We selected 10 non-small cell lung cancer patients developed with RILF after postoperative radiation therapy (PORT) and delineated VF on the follow-up chest CT scanned at more than 6 months after radiotherapy. Three radiation oncologists independently delineated VF to investigate the interobserver variability. Three times of delineation of VF was performed by two radiation oncologists for the analysis of intraobserver variability. We analysed the concordance index (CI) and inter/intra-class correlation coefficient (ICC). Results: The median CI was 0.61 (range, 0.44 to 0.68) for interobserver variability and the median CIs for intraobserver variability were 0.69 (range, 0.65 to 0.79) and 0.61(range, 0.55 to 0.65) by two observers. The ICC for interobserver variability was 0.974 (p < 0.001) and ICCs for intraobserver variability were 0.996 (p < 0.001) and 0.991 (p < 0.001), respectively. Conclusion: CT-based measurement of VF with patients who received PORT was a highly consistent and reproducible quantitative method between and within observers.