Physical and chemical modification of ordered mesoporous carbon materials for CF4 adsorption

Park, Hyeonji Sungkyunkwan University 2023 국내석사

Due to the increase in global energy demand, greenhouse gas concentrations are increasing every year. Among the PFCs, which are widely used in the semiconductor industries and possess extremely high global warming potentials, carbon tetrafluoride (CF4) contributes significantly to the greenhouse effect despite its low atmospheric concentration. In order to prevent CF4 emission, adsorption is considered a potential option because of its relatively low cost and convenience to operate without producing byproducts. Various candidates with large surface area and highly porous structure have been studied for CF4 adsorption, and carbon-based adsorbents are especially promising due to the merits of physical and chemical stability and facile synthesis. In this research, physical and chemical modification of ordered mesoporous carbon (OMC) materials were conducted. The micropore developed OMC with phosphoric acid catalyst and boron oxide doped OMC for addition of Lewis acid sites were synthesized to enhance the CF4 adsorption performance. In order to evaluate the adsorption capacities of the materials, CF4 dynamic adsorption, isotherms, breakthrough experiments were performed. 전 세계 에너지 수요의 증가로 인해 온실가스 농도는 매년 증가하고 있다. 소량으로도 문제를 일으키는 온실가스 중 CF4는 반도체 제조 공정에서 사용되며 안정적인 사면체 구조로 인해 대기 수명이 5만년으로 매우 길다. CF4 배출을 방지하기 위한 방법들 중 흡착은 상대적으로 비용이 저렴하고 부산물을 생성하지 않고 운영이 편리하여 효과적이다. CF4 흡착을 위해 넓은 표면적과 높은 다공성 구조를 가진 다양한 물질들이 연구되어 왔으며, 특히 탄소계 흡착제는 물리적, 화학적 안정성과 합성이 용이하다는 장점 때문에 유망하다. 본 연구에서는 메조기공성 탄소(OMC) 물질의 물리적 및 화학적 변형을 수행하였고, 인산 촉매를 사용한 미세기공이 발달된 OMC와 boron oxide가 도핑된 OMC를 합성하여 기존의 일반적인 OMC에 비해 CF4 흡착 성능을 향상시켰다. 물질의 흡착능을 평가하기 위해 CF4 동적 흡착, 등온선, 파과 실험을 수행하였다.

Effects of Tamsulosin on Urinary Bladder Function and Neuronal Activity in the Voiding Centers of Rats with Cyclophosphamide-induced Overactive Bladder

Ji-Hyeon Park 가천대학교 대학원 2014 국내석사

Purpose: The overactive bladder (OAB) syndrome is characterized by urgency usually with frequency and nocturia. Tamsulosin, α1-adrenergic receptor antagonist, is widely used to reduce symptoms of urinary obstruction and prostatic hyperplasia. Tamsulosin can across the blood-brain barrier. We investigated the effects of tamsulosin on the symptoms of OAB in relation to neuronal activity using rats. Methods: Adult female Sprague-Dawley rats, weighing 250 ± 10 g (9 weeks old), were used in this study. The animals were divided into five groups (n = 8 in each group): control group, OAB-induced group, OAB-induced and 0.01 mg/kg tamsulosin-treated group, OAB-induced and 0.1 mg/kg tamsulosin-treated group, and OAB-induced and 1 mg/kg tamsulosin-treated group. OAB was induced by intraperitoneal injection of cyclophosphamide (75 mg/kg) every third day for 10 days. The rats in the tamsulosin-treated groups orally received tamsulosin once a day for 14 consecutive days at the respective dose of the groups, starting 1 day after the induction of OAB. Cystometry for bladder pressure determination, immunohistochemistry for c-Fos, nicotinamide adenine dinucleotide phosphate-diaphorase histochemistry for nitric oxide synthase (NOS) in the neuronal voiding centers and western blot for inducible NOS in the bladder were conducted. Results: Cyclophosphamide injection enhanced contraction pressure and time, representing the induction of OAB. Contraction pressure and time were significantly suppressed by tamsulosin treatment. c-Fos and NOS expressions in the neuronal voiding centers were enhanced by induction of OAB. OAB-induced c-Fos and NOS expressions were suppressed by tamsulosin treatment. Conclusions: Tamsulosin exerts inhibitory effect on neuronal activation in the neuronal voiding centers of OAB. The present results suggest the possibility that tamsulosin is effective therapeutic modality for ameliorating the symptoms of OAB.

Investigation of canine caudal articular process dysplasia of thoracic vertebrae using computed tomography: prevalence and characteristics

Park, Ji Hyeon 충북대학교 2022 국내석사

Caudal articular process dysplasia is a congenital vertebral malformation that considered results from the failure of ossification center of articular process located in vertebrae, which includes aplasia or hypoplasia. In previous studies, caudal articular process dysplasia was reported to be common in small and chondrodystrophic dogs however, investigated in limited breeds (large, chondrodystrophic, and small breeds). We aimed to confirm the prevalence and the characteristics of caudal articular process dysplasia in various twenty four breeds dogs, and also to investigate the association of spinal cord myelopathy and caudal articular process dysplasia in neurologically abnormal dogs. Our hypothesis is that in toy and small breeds, the proportion of vertebrae with caudal articular process dysplasia will be higher than medium and large breeds, and occurrence rate of spinal cord myelopathy will be higher in dogs with caudal articular process dysplasia due to spinal instability. In this multicenter, retrospective, and cross-sectional study, the clinical records and thoracic vertebral column CT images of 717 canine patients between February 2016, and August 2021 were evaluated and if MRI was taken, that information was also included. Overall, 337 of 717 dogs (47.0%) had thoracic caudal articular process dysplasia. There were significant differences of affected vertebrae with caudal articular anomalies between breeds sorted by weight (P<0.0001). A total of 66.4% of toy breeds, 39.0% of small breeds, 20.2% of medium breeds, and 6.0% of large breeds were founded to be affected by more than one caudal articular process dysplasia in CT images. The most affected vertebra was T4 in toy (48.1%) and small breeds (20.8%), and T5 in medium (20.8%) and large breeds dogs (5.0%). In all groups, prevalence of caudal articular process dysplasia between T1 and T9 was higher than post-diaphragmatic vertebrae (T10-T13). In neurologically abnormal 25 dogs that had both spinal cord myelopathy and caudal articular process anomalies in thoracic vertebrae underwent MRI and CT, there was 41 herniated discs. But, there was one patient had both caudal articular process dysplasia and herniated disc at the same level. Also, caudal articular process dysplasia associated non-compressive spinal myelopathy was found in only one case. It is concluded that caudal articular process dysplasia would be incidentally founded on CT and no clear association between caudal articular process dysplasia and spinal cord myelopathy was found. However, in rare cases, it its necessary to consider it as a predisposing factor to intervertebral disc disease.

Application of a validated BAC-based array CGH platform for prenatal diagnosis in South Korea

박지현 CHA Univ. 2010 국내박사

Background: While conventional G-banded karyotyping still remains a gold standard in prenatal genetic diagnoses, conventional karyotyping can hardly detect small deletion/duplication resulting in congenital anomalies and mental retardation. Recently, because of rapid result and ability to detect a very small genomic imbalance which cannot be detected by conventional karyotyping, the widespread adoption of array Comparative Genomic Hybridization (array CGH) technology for postnatal genetic diagnoses has led to increasing interest in the use of this same technology for prenatal diagnosis. Thus, we designed a targeted low density BAC array based prenatal DNA chip specifically for 26 known genetic syndromes of medically significant and relatively common chromosomal alterations. We evaluated the value of our own designed DNA chip as a prenatal diagnostic tool to detect submicroscopic deletions/duplications and aneuploidies of chromosome. Here, we describe the development and application of a bacterial artificial chromosome(BAC) -based DNA chip that is being used for prenatal diagnosis in South Korea. Results: We have designed a target BAC-based array CGH platform (MacArrayTM M-chip). This ap). This ap). Thispecifically targets submicroscopic deletions and duplications for 26 known genetic syndromes of medical significance as well as frequently-observed common chromosomal aneuploidies that are observed prenatally. To validate the ap). , we obtained genomic DNA from 132 cell lines containing relevant genomic imbalances and specific chromosomal aneuploidies.p)Experiments were per. Thed in a blinded manner and all known genomic alterations were success.ully identified. We then applied this ap). CGH platform to 94 amniotic fluid specimens that were also subjected to conventional karyotyping. Due to the targeted nature of this ap). CGH platform, certain chromosomal aberrations could not be detected by ap). CGH, but were identified via romosomal aberrations couinclud coubalanced chromosomal reap).osoments: 2 cases of imo(9) and 1 case of t(8;11). Howet(8, certain chromosomal aberrations were detected with this ap). platform that were not oberserved by nal karyochromosomal analysis. For exaalle, we identified eight cases of microdeletions in the Yq11.23 chromosomal region,romosomot bors the DAZ gene, couin. lwereto non-obstructyochspermatogenesis. Rts: 2fluol rcent in situ hybridization (FISH) analysis confirmed the deletion in all eight cases. Conclusions: We have successfully designed and applied a BAC-based array CGH platform for prenatal diagnosis. This array CGH platform can be used in conjunction with conventional karyotyping and will provide rapid and accurate diagnosis for the targeted genomic regions while eliminating the need to interpret clinically-uncertain genomic regions – certain copy number variants (CNVs). 임신중 태아의 염색체이상을 확진하기 위해서는 여전히 세포유전학 검사인 핵형검사(Conventional Karyotyping)가 gold standard로 여겨지고 있지만 이 검사법은 배양에 상당한 시간을 요구하며 특히 프라더윌리 증후군, 안젤만 증후군, 스미스-마게니스 증후군, 디저지 증후군과 같은 미세결손 증후군은 발견할 수 없다는 한계를 가지고 있습니다. 이들 미세결손 증후군은 발생빈도가 그리 높지는 않지만, 매우 심각한 기형 및 정신 지체를 동반하는 경우가 많아 이들 을 산전에 진단할 수 있는 검사법을 찾는 것은 매우 중요합니다. 최근 arrayCGH(comparative genomic hybridization) 기술을 이용한 DNA 분석은 비정배체 (aenuploidy) 뿐 아니라 미세결손 증후군을 동시에 검사할 수 있고 배양이 필요없어 2⃇-3일 이내에 검사가 완료될 수 있는 장점을 가지고 있어 핵형검사에 추가적인 검사법으로 대두되고 있습니다. 이에 본 연구에서는 한국인의 산전검진에 적합한 low-density BAC-based DNA chip을 고안하고 이 DNA chip의 산전검사법으로서의 유용성과 효용성을 연구하였습니다. 본 연구에서는 임상적 의미가 있고 비교적 빈도가 높은 26 종류의 유전성 질환 (7 종류의 비정배체 와 19 종류의 미세결손 증후군) 을 검사할 수 있는 DNA chip을 고안하였고 이 DNA chip의 유용성을 검증하기 위하여 우선 Coriell Cell Resource로부터 구입한 유전성 질환 샘플 132개를 Blind manner 로 실험을 시행하여 132 reference sample 에 대해 모두 정확한 결과를 얻을 수 있었다. 또한 임상실험을 위해 2007년 9월부터 2008년 7월까지 강남차병원에서 다양한 원인으로 염색체 검사가 필요하여 임신 15주에서 임신 20주 사이에 양수검사를 받은 산모 94명을 대상으로 DNA chip study와 핵형검사를 시행하여 두 결과를 비교하였다. 임상실험 결과 2 례의 inv(9)과 1 례의 t(8;11)등 3 례의 balanced chromosomal rearrangements의 경우 핵형검사상에서는 진단이 되었으나 DNA chip study에서는 진단이 되지 않았는데 이는 array CGH가 염색체에서 발생하는 수적변화 (copy number change)와 그 위치를 알려주는 분자 세포유전학 기술로서의 특성에 기인한다. 한편 DNA chip study의 경우 핵형검사만으로는 알수 없었던 8 례의 Yq11.23 microdeletion syndromes을 발견할 수 있었는데 이는 non-obstructive spermatogenesis와 연관되어 남성불임을 유발하는 것으로 알려져 있어 불임 남성의 진단과 유전상담에 매우 유용하게 이용될 수 있다. 뿐만 아니라 본 DNA chip의 경우 이미 임상적 의미가 잘 알려진 유전질환에 연관된 probe 들로 구성이 되어 있어, 임상적 의미가 애매하거나 benign copy number variation 등의 결과가 나온 경우는 없었다. 결론적으로 본 연구에서는 181 개라는 소수의 probes로 구성된 저밀도 산전진단 DNA chip을 고안하고 reference 샘플과 환자의 샘플에 대해 각각 실험을 하여 성공적인 결과를 얻음으로써, 저밀도의 DNA chip이 고식적 핵형검사의 부가적인 검사로서 빠른 시간내에 비정배체뿐만 아니라 미세결손 증후군에 대한 선별검사로서의 임상적 유용성과 효용성이 있음을 보여주었다. 핵심되는 말 : array CGH(comparative genomic hybridization), 염색체 이상, 산전진단, 미세결손 증후군