• 한국가시화정보학회지
• /
• 제19권1호
• /
• pp.50-56
• /
• 2021

With the advances in recent nanotechnology, mass transport phenomena have been receiving large attention both in academic researches and industrial applications. Nonetheless, it is not clearly determined which parameters are dominant at nanoscale mass transport. Especially, membrane is a kind of technology that use a selective separation to secure fresh water. The development of great separation membrane and membrane-based separation system is an important way to solve existing water resource problems. In this study, glass fiber-based membranes which are treated by graphene oxide (GO), poly-styrene sulfonate (GOP) and sodium dodecyl sulfate (GPS) were fabricated. Mass transport parameters were investigated in terms of material-specific and structure-specific dominance. The 3D structural information of GO, GOP, and GPS was obtained by using synchrotron X-ray nano tomography. In addition, electrostatic characteristic and water absorption rate of the membranes were investigated. As a result, we calculated internal structural information using Tomadakis-Sotrichos model, and we found that manipulation of surface characteristics can improve spacer arm effect, which means enhancement of water permeability by control length of ligand and surface charge functionality of the membrane.

• PNF and Movement
• /
• 제11권1호
• /
• pp.55-62
• /
• 2013

Purpose : This study was assessed muscle activity and onset time in trunk and upper extremity on functional reaching. Methods : The participant was 18 female(young 10, old 8). As functional reaching, we collection data by using EMG(MP150) on transverse abdominis, external oblique, erector spinae, deltoid middle and serratus anterior. Results : 1) In functional reaching, transverse abdominis, external oblique, erector spinae and deltoid middle muscle activity was augmented on old female(p>.05). Serratus anterior was augmented on young female(p>.05). 2) In functional reaching, transverse abdominis and erector spinae muscle onset time is significantly faster old female than young female(p<.05). External oblique and serratus anterior muscle onset time is faster old female than young female(p>.05). 3) As increase of age muscle activity of external oblique was more increased that we found .511 a coefficient correlation and onset time more faster on transverse abdominis and erector spinae were each -.492 and -.554 coefficient correlation. Conclusion : The muscle activity and onset time was difference in functional reaching according to ageing and task context. It is necessary concentration and attention to old female than young female. Therefore, these results suggest that importance of anticipatory postural control and selective strategy of postural control.

• 한국폐기물자원순환학회지
• /
• 제35권7호
• /
• pp.647-652
• /
• 2018

The emission of nitrogen oxides has a great environmental impact. It leads to Los Angeles type smog, and it recently has attracted attention as a source of ultrafine dust. The main sources of nitrogen oxides are internal combustion engines and industrial boilers. These emission sources are processes that are essential for human industrial activities, so the regulation of original use is impossible. Therefore, special control methods should be applied to reduce NOx emissions into the atmosphere. In this study, we investigated how the supply of ER and urea influences the removal of nitrogen oxides from SRF combustion boilers. Experimental results show that the removal efficiency of nitrogen oxides can be up to 80% under the conditions of ER 2.0 and a urea feed of 0.5 LPM.

• 대한금속재료학회지
• /
• 제46권5호
• /
• pp.296-303
• /
• 2008

Hydrogen permeation through dense palladium-based membranes has attracted the attention of many scientists largely due to their unmatched potential as hydrogen-selective membranes for membrane reactor applications. Although it is well known that the permeation mechanism of hydrogen through Pd involves various processes such as dissociative adsorption, transitions to and from the bulk Pd, diffusion within Pd, and recombinative desorption, it is still unclear which process mainly limits hydrogen permeation at a given temperature and hydrogen partial pressure. In this study, we report an all-electron density-functional theory study of hydrogen permeation through Pd membrane (using VASP code). Especially, we focus on the variation of the energy barrier of the penetration process from the surface to the bulk with hydrogen coverage, which means the large reduction of the fracture stress in the brittle crack propagation considering Griffith's criterion. It is also found that the penetration energy barrier from the surface to the bulk largely decreases so that it almost vanishes at the coverage 1.25, which means that the penetration process cannot be the rate determining process.

• 한국축산식품학회지
• /
• 제41권5호
• /
• pp.883-893
• /
• 2021

Clostridium difficile present in feces of food animals may contaminate their meats and act as a potential source of C. difficile infection (CDI) to humans. C. difficile resistance to antibiotics, its production of toxins and spores play major roles in the pathogenesis of CDI. This is the first study to evaluate C. difficile prevalence in retail raw animal meats, its antibiotics susceptibilities and toxigenic activities in Al-Jouf, Saudi Arabia. Totally, 240 meat samples were tested. C. difficile was identified by standard microbiological and biochemical methods. Vitek-2 compact system confirmed C. difficile isolates were 15/240 (6.3%). Toxins A/B were not detected by Xpect C. difficile toxin A/B tests. Although all isolates were susceptible to vancomycin and metronidazole, variable degrees of reduced susceptibilities to moxifloxacin, clindamycin or tetracycline antibiotics were detected by Epsilon tests. C. difficile strains with reduced susceptibility to antibiotics should be investigated. Variability between the worldwide reported C. difficile contamination levels could be due to absence of a gold standard procedure for its isolation. Establishment of a unified testing algorithm for C. difficile detection in food products is definitely essential to evaluate the inter-regional variation in its prevalence on national and international levels. Proper use of antimicrobials during animal husbandry is crucial to control the selective drug pressure on C. difficile strains associated with food animals. Investigating the protective or pathogenic potential of non-toxigenic C. difficile strains and the possibility of gene transfer from certain toxigenic/ antibiotics-resistant to non-toxigenic/antibiotics-sensitive strains, respectively, should be worthy of attention.

• 한양메디칼리뷰
• /
• 제33권1호
• /
• pp.59-64
• /
• 2013

Cancer remains the leading cause of death worldwide despite intense efforts in developing innovative treatments. Current approaches in cancer therapy are mainly directed to a selective targeting of cancer cells to avoid potential side effects associated with conventional therapy. In this respect, Natural killer (NK) cells have gained growing attention and are now being considered as promising therapeutic tools for cancer therapy owing to their intrinsic ability to rapidly recognize and kill cancer cells, while sparing normal healthy cells. NK cells play a key role in the first line of defense against transformed and virus-infected cells. NK cells sense their target through a whole array of receptors, both activating and inhibitory. Functional outcome of NK cell against target cells is determined by the balance of signals transmitted from diverse activating and inhibiting receptors. Despite significant progress made in the role of NK cells attack as a pivotal sentinel in tumor surveillance, the molecular has been that regulate NK cell responses remain unclear, which restricts the use of NK cells as a therapeutic measure. Accordingly, current efforts for NK cell-based cancer therapy have largely relied on the strategies that are based on the manipulation of inhibitory receptor function. However, if we better understand the mechanisms governing NK cell activation, including those mediated by diverse activating receptors, this knowledge can be applied to the development of optimal design for cancer immunotherapy by targeting NK cells.

• Korean Journal of Radiology
• /
• 제25권5호
• /
• pp.449-458
• /
• 2024

Selective fascicular involvement of the median nerve trunk above the elbow leading to anterior interosseous nerve (AIN) syndrome is a rare form of peripheral neuropathy. This condition has recently garnered increased attention within the medical community owing to advancements in imaging techniques and a growing number of reported cases. In this article, we explore the topographical anatomy of the median nerve trunk and the clinical features associated with AIN palsy. Our focus extends to unique manifestations captured through MRI and ultrasonography (US) studies, highlighting noteworthy findings, such as nerve fascicle swelling, incomplete constrictions, hourglass-like constrictions, and torsions, particularly in the posterior/posteromedial region of the median nerve. Surgical observations have further enhanced the understanding of this complex neuropathic condition. High-resolution MRI not only reveals denervation changes in the AIN and median nerve territories but also illuminates these alterations without the presence of compressing structures. The pivotal roles of high-resolution MRI and US in diagnosing this condition and guiding the formulation of an optimal treatment strategy are emphasized.

• 수면정신생리
• /
• 제12권2호
• /
• pp.122-132
• /
• 2005

배 경：본 연구에서는 청년기 기면병 환자의 인지기능 변화를 평가하고자 하였다. 청년기 기면병 환자의 인지기능과 수면 증상과의 관계도 관찰하였다. 방 법：17세 이상 35세 이하의 기면병 환자 18명과 정상대조군 18명을 모집하여 연구를 시행하였다. 탈력발작이 있고, HLA $DQB_1$ *0602 양성인 경우만을 기면병 대상군으로 하였다. 기면병 대상군과 정상대조군에게 13종의 신경심리검사(Wisconsin 카드분류, Trail making, Stroop, Ruff, 청각순차합산, 바꿔쓰기, 숫자 외우기, 공간 외우기, Rey 기억력, California 언어학습, 통제단어연상, Boston 이름대기, 굽은 막대 검사)를 시행하여 양군을 비교하였다. 그리고, 기면병 대상군의 신경심리검사 결과와 Epworth 졸음증 척도, Ullanlinna 기면병 척도, 야간수면다원검사 및 입면 잠복시간 반복검사 결과 사이의 상관관계를 분석하였다. 결 과：기면병 대상군은 정상 대조군에 비해 2.0초 간격과 2.4초 간격의 청각순차합산, 바꿔쓰기, 공간 외우기 정방향 검사에서 수행능력이 저조하였다(t=3.86, p<0.001；t=-2.47, p=0.02；t=-3.95, p<0.001；t=-2.22, p=0.03). 다른 신경심리검사에서는 양 군간에 유의한 차이가 없었다. 기면병 대상군에서 저하된 신경심리검사 결과는 Epworth 졸음증 척도나 Ullanlinna 기면병 척도와 유의한 상관관계가 없었으며, 야간수면다원검사나 입면잠복시간 반복검사와도 유의한 상관관계가 없었다. 결 론：본 연구에서 기면병 환자군의 주의력이 저하되어 있음을 관찰하였다. 그러나 주의력 저하는 주간 졸음증과 유의한 상관을 보이지 않았다. 따라서 기면병 환자의 주의력 저하는 주간 졸음증의 개선만으로 호전시킬 수 없다는 점을 시사한다.

• 정신신체의학
• /
• 제25권2호
• /
• pp.210-217
• /
• 2017

연구목적 조현병 환자의 선택적 주의력을 평가하기 위해 집중력 네트워크 검사(Attention Network Test)가 널리 사용되고 있으나, 조현병 환자들이 시행한 집중력 네트워크 검사 결과의 신뢰도에 대해서는 연구된 바가 거의 없다. 본 연구에서는 조현병 환자를 대상으로 주의력 네트워크 검사의 검사-재검사 신뢰도를 연구하여 이 검사의 심리측정적 특성(psychometric properties)을 평가하고자 하였다. 방 법 조현병 환자 14명, 일반인 23명이 본 연구에 참여하였다. 실험대상자들은 일주일 간격으로 두 번 동일한 시간에 주의력 네트워크 검사를 수행하였다. 검사-재검사 신뢰도를 분석하기 위해 피어슨 상관분석(Pearson correlation)과 급내 상관분석(Intra-class correlation)을 시행하였다. 결 과 조현병 환자들은 집중력 네트워크 검사의 측정 항목 중 평균 반응시간, 지향 효과, 갈등처리 효과에서 높은 정도의 상관관계를 보였다. 정확도에서는 중간부터 높은 정도의 상관관계를 보였으며, 각성 효과와 갈등처리 오답률에서는 중간 정도의 상관관계를 보였다. 한편, 일반인은 평균 반응시간에서 높은 정도의 상관관계를 보였고, 갈등처리 오답률에서 중간부터 높은 정도의 상관관계를 보였다. 또한, 각성 효과, 지향 효과, 갈등처리 효과에서 중간 정도의 상관관계를 보였으며, 각성 오답률에서 중간 정도의 역상관관계를 보였다. 결 론 본 연구 결과에 의하면, 조현병 환자와 일반인 모두에서 중간 정도 이상의 신뢰도를 보이는 집중력 네트워크 검사 항목은 평균 반응시간, 각성 효과, 지향 효과, 갈등처리 효과, 갈등처리 오답률 항목이다. 그러므로 집중력 네트워크 검사를 사용하여 조현병 환자군 대 일반 대조군 실험을 시행할 때, 상기 항목들의 결과를 비교하는 것이 신뢰도 측면에서 추천된다.

• 생물정신의학
• /
• 제2권2호
• /
• pp.205-217
• /
• 1995

1) Paroxetine이 5-HT흡수에 가장 강력하고, 선택적이었으며, 그 다음이 fluvoxamine, sertraline, fluoxetine순이었고, sertraline은 다른 SSRIs와는 달리 NE보다 DA억제작용이 더 강했다. 2) Paroxetine이 muscarinic cholinergic 수용체에 대한 친화력이 다소 높았을 뿐, 전반적으로 SSRIs는 histamine $H_1$과 ${\alpha}_1$에 대한 친화력은 약했다. 3) Paroxetine은 ${\beta}$-adrenoceptor와 cyclic AMP에 영향을 미치지 않는 반면, sertraline은 ${\beta}$-adrenoceptor와 cyclic AMP의 감소를 가져왔다. 4) SSRIs의 생체이용율은 대략 50%이었으며, 투약후 2~8시간 사이에 최고혈중농도에 도달하였으며, 특히 sertraline은 음식물과 같이 복용시 혈장의 concentration time curve와 최고 농도를 증가시켰다. 5) Sertraline은 혈중농도가 용량에 비례하였으며, 모든 SSRIs는 비교적 큰 용량분포를 보이고, 높은 비율로 혈장 단백질과 결합되어 있었다. 6) Fluoxetine 대사물의 5-HT 억제 작용이 제일 강했다. 그러나 paroxetine, fluoxetine, sertraline 대사물은 강도는 서로 다르지만 간의 isoenzyme IID6를 억제하며, 그 중에서 paroxetine의 억제작용이 제일 강력하다. 7) Sertraline은 TCAs나 haloperidol과 병합사용시 TCAs나 haloperidol의 혈중농도의 유의한 변화가 없었으며, MAOI A형인 moclobemide와 비교적 안전하게 병용 치료할 수 있다. 8) SSRIs는 TCAs와 비교해볼 때 치료효과는 유사하였으나 fluvoxamine은 자살사고에, paroxetine은 우울중에서 나타나는 불안과 운동성 초조증에 효과적이다. 9) 급성 우울증 삽화시 현저한 효과를 보인 후 적어도 4개월 이상의 유지치료기간이 필요하다. 10) SSRIs는 위장관계통의 부작용이 가장 많았고, 부작용은 일반적으로 분복한 경우가 적었다.