• 제목/요약/키워드: biochemical factor

검색결과 387건 처리시간 0.026초

자외선 경화형 점착제의 접착 및 재박리 특성 (Adhesive and Removable Characteristics of UV Curable Adhesive)

  • 김인범;이명천
    • Korean Chemical Engineering Research
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    • 제46권1호
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    • pp.76-81
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    • 2008
  • 아크릴계 점착제를 합성한 후 이관능성 혹은 육관능성 우레탄-아크릴레이트 올리고머를 혼합하여 자외선 경화형 점착제를 제조하였다. 올리고머 종류 및 함량을 변화시켜 그에 따른 접착력 변화와 재박리 특성을 조사하였다. 자외선 경화전에는 올리고머의 함량의 증가에 따라 박리력이 증가하였으나 자외선 경화 후에는 감소하는 경향을 보였다. 저장 탄성률(G')이 낮을수록 박리력은 증가하지만 점착제 내부의 상용성과 손실계수(tan ${\delta}$) 값에 따라 점착제의 박리정도와 접착력에 영향을 주는 것을 확인할 수 있었다.

Src Redox Regulation: There Is More Than Meets the Eye

  • Chiarugi, Paola
    • Molecules and Cells
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    • 제26권4호
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    • pp.329-337
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    • 2008
  • Src-family kinases are critically involved in the control of cytoskeleton organization and in the generation of integrin-dependent signaling responses, inducing tyrosine phosphorylation of many signaling and cytoskeletal proteins. Activity of the Src family of tyrosine kinases is tightly controlled by inhibitory phosphorylation of a carboxy-terminal tyrosine residue, inducing an inactive conformation through binding with its SH2 domain. Dephosphorylation of C-ter tyrosine, as well as its deletion of substitution with phenylalanine in oncogenic Src kinases, leads to autophosphorylation at a tyrosine in the activation loop, thereby leading to enhanced Src activity. Beside this phophorylation/dephosphorylation circuitry, cysteine oxidation has been recently reported as a further mechanism of enzyme activation. Mounting evidence describes Src activation via its redox regulation as a key outcome in several circumstances, including growth factor and cytokines signaling, integrin-mediated cell adhesion and motility, membrane receptor cross-talk as well in cell transformation and tumor progression. Among the plethora of data involving Src kinase in physiological and pathophysiological processes, this review will give emphasis to the redox component of the regulation of this master kinase.

Are women with small endometriomas who undergo intracytoplasmic sperm injection at an elevated risk for adverse pregnancy, obstetric, and neonatal outcomes?

  • Verit, Fatma Ferda;Kucukakca, Ayse Seyma Ozsuer
    • Clinical and Experimental Reproductive Medicine
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    • 제48권1호
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    • pp.80-84
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    • 2021
  • Objective: The aim of the study was to investigate pregnancy, obstetric, and neonatal outcomes in women with small (<4 cm) unilateral endometriomas. Methods: This retrospective study included 177 patients: 91 patients with small endometriomas and 86 controls with unexplained or tubal factor infertility who were treated at the Süleymaniye Gynecology and Maternity Training and Research Hospital Infertility Unit between January 2010 and July 2015. The groups were matched with regards to demographic characteristics such as age, body mass index, and infertility duration. All of the women in this study conceived via intracytoplasmic sperm injection. We compared pregnancy, obstetric, and neonatal outcomes between these groups. Results: Women with endometriomas had a higher biochemical pregnancy rate, but lower clinical pregnancy and live birth rates than women with unexplained and tubal factor infertility (p<0.05 for all). However no significant differences were found in terms of obstetric and neonatal complications between the two groups (p>0.05 for all). Conclusion: In this study, we found that women with endometriomas less than 4 cm were more prone to early pregnancy complications. We also showed that this group did not have any increased risks of late pregnancy, obstetric, and neonatal complications.

뇌유래신경영양인자와 뇌 신경가소성: 비약물적 개입 (Brain-Derived Neurotrophic Factor and Brain Plasticity: Non-Pharmacological Intervention)

  • 김낙영;임현국
    • 생물정신의학
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    • 제30권1호
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    • pp.1-6
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    • 2023
  • Many psychiatric disorders are associated with brain functional dysfunctions and neuronal degeneration. According to the research so far, enhanced brain plasticity reduces neurodegeneration and recovers neuronal damage. Brain-derived neurotrophic factor (BDNF) is one of the most extensively studied neurotrophins in the mammalian brain that plays major roles in neuronal survival, development, growth, and maintenance of neurons in brain circuits related to emotion and cognitive function. Also, BDNF plays an important role in brain plasticity, influencing dendritic spines in the hippocampus neurogenesis. Changes in neurogenesis and dendritic density can improve psychiatric symptoms and cognitive functions. BDNF has potent effects on brain plasticity through biochemical mechanisms, cellular signal pathways, and epigenetic changes. There are pharmacological and non-pharmacological interventions to increase the expression of BDNF and enhance brain plasticity. Non-pharmacological interventions such as physical exercise, nutritional change, environmental enrichment, and neuromodulation have biological mechanisms that increase the expression of BDNF and brain plasticity. Non-pharmacological interventions are cost-effective and safe ways to improve psychiatric symptoms.

저산소환경에 의한 송사리(Oryzias dancena)의 Stanniocalcin-2와 Hypoxia-Inducible Factor-1α mRNA 발현의 변화 (Changes in Stanniocalcin-2 and Hypoxia-Inducible Factor-1α mRNA Expression in Medaka Oryzias dancena Exposed to Acute Hypoxia)

  • 신지혜;손영창
    • 한국수산과학회지
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    • 제46권1호
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    • pp.70-76
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    • 2013
  • Some fish live in aquatic environments with low or temporally changing $O_2$ availability. Variation in dissolved oxygen (DO) levels requires behavioral, physiological, and biochemical adaptations to ensure the uptake of sufficient $O_2$. Several species are relatively well adapted to tolerate low $O_2$ partial pressures (hypoxia). The medaka (Oryzias dancena ) is an important model organism for biomedical research that shows remarkable tolerance to hypoxia. We investigated the regulation and role of hypoxia-inducible factor-1 (HIF-$1{\alpha}$) as a general hypoxia-response gene and stanniocalcin-2 (STC2), which is one of the genes regulated by HIF-$1{\alpha}$ in mammals under hypoxia. We subjected adult male medaka to the following three acute hypoxia regimes: 1, 24, and 72 h at DO = $1.8{\pm}0.5$ ppm. The changes in STC2 and HIF-$1{\alpha}$ mRNA were monitored using quantitative real-time reverse-transcription PCR. We found strong upregulation of HIF-$1{\alpha}$ mRNA in the livers of fish exposed to hypoxia. Hypoxia rapidly upregulated STC-2 mRNA expression in muscle, but not in the brain, gills, liver, or intestine. Therefore, unlike in mammals, hypoxia might regulate O. dancena STC-2 expression in an HIF-$1{\alpha}$-independent manner.

치매(痴呆)에 관(關)한 동서의학적(東西醫學的) 비교(比較) 고찰(考察) (A Comparative Consideration of Dementia in Oriental and Occidental Medicine)

  • 이동원;신길조;이원철
    • 대한한방내과학회지
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    • 제16권1호
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    • pp.1-16
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    • 1995
  • This study was done in order to investigate the etiology and pathology of dementia in the variety literature. Dementia in elderly persons(above the age of 60) mainly classfied Alzheimer disease and Cerebral vascular dementia. The results were as follows: 1. Dementia patients have abnormal mental function, who have no mental weakness but defects of memory, verbal disturbance, behavior disturbance and loss of intellectual function. 2. Dementia regard as 'me-beng(?病)', 'jeon-gwang(癲狂)', and 'heo-ro(虛勞)' in oriental medicine and the symptom is a silence with no response, mixing, a crying or a laugh, a stranger behavior and a amnesia; disturbances of speech, emotion, behavior. 3. Dementia caused by Alzheimer disease, Multi infarct dementia, Parkinson's disease, sequelae of acute CO poisoning, head injury and alcoholism(occidental medically) and the 'Dam(痰) and Damhwa(痰火), weakness of heart and spleen(心脾虛) caused by pent up anger of seven emotions(七情鬱結), the weakness of liver and kidney(肝腎不足)(oriental medically). 4. The causes of Alzheimer disease are various; a heredity factor, a morphological factor of brain tissues, a psychological factor and a biochemical factor (occidental medically) ; the 'Dam(痰) and Damhwa(痰火) caused by weakness of the internal organs and disturbance of the emotions(oriental medically). 5. Cerebral vascular dementia caused by loss of the certain cerebral neurons and oriental medically caused by obstruction of 'dam(痰)' or 'eo heul(瘀血)'. It is recommended that further study of many sided investigations, specially against a weakness of spiritual functions and a certain neurotoxin in the future.

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Aeromonas sp. MN44의 특성과 망간 산화에 관한 연구 (A Study on the Manganese Oxidation and Characteristics of Aeromonas sp)

  • 구종서;박경량
    • 생명과학회지
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    • 제15권1호
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    • pp.94-99
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    • 2005
  • 충청남도 목천과 충청북도 오창 근교의 토양으로부터 망간을 산화하는 64 집락을 분리하고 이 중 망간 산화능이 가장 우수한 한 균주를 최종 선별하여 생리, 생화학적 특성을 조사하고, 16S rRNA 염기 서열분석 등을 통하여 동정한 결과 최종 선별된 균주는 Aeromonas sp. MN44로 확인되었다. 최종 선별된 Aeromenas sp. MN44는 lactose를 제외한 여러 당들은 이용하지 못하였으며, 중금속내성은 lithium과 manganese에 대해서는 mg/ml 단위의 높은 농도까지 중금속 내성을 가지고 있었지만 cadmium에는 전혀 내성을 나타내지 않았다. 또 kanamycin, chloramphenicol, ampicillin, tetracycline, spectinomycin등 조사한 모든 항생제에 대해 전혀 내성을 갖지 않았다. Aeromonas sp. MN44가 생성하는 망간산화물질의 최적 pH는 pH 7.4로 확인되었으며, 이 균이 생성하는 망간 산화 factor는 proteinase K와 가열처리에 의해 저해되는 단백질이고, ammonium sulfate 침전과 ion exchange chromatography 그리고 gel filtration의 단계를 통해 부분 정제한 망간 산화 factor의 분자량은 약 113 kDa로 확인되었다.

Clinical Value of Eukaryotic Elongation Factor 2 (eEF2) in Non-small Cell Lung Cancer Patients

  • Sun, Hong-Gang;Dong, Xue-Jun;Lu, Tao;Yang, Ming-Feng;Wang, Xing-Mu
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권11호
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    • pp.6533-6535
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    • 2013
  • Background: The purpose of this study was to evaluate a new type of tumor biomarker, eukaryotic elongation factor 2 (eEF2), in serum for the early diagnosis, confirmative diagnosis as well as assessment of treatment of non-small cell lung cancer (NSCLC). Methods: 130 patients with NSCLC and 50 healthy individuals undergoing physical examination in our hospital provided the observation and healthy control groups. An enzyme linked immune sorbent assay (ELISA) method was applied to determine serum eEF2 levels. Serum neuron specific enolase (NSE) and squamous cell carcinoma antigen (SCC) levels in the observation group were assessed with an automatic biochemical analyzer. Results: The median levels of eEF2 in the serum of NSCLC patients was found to be significantly higher than the healthy control group (p < 0.01) and it was markedly higher in stages III, IV than stages I, II (p < 0.05). eEF2 was higher with tumor size ${\geq}2$ cm than <2 cm (P< 0.01). Furthermore, two weeks after surgery patients showed a significant trend for eEF2 decrease (p < 0.05). Conclusions: The eukaryotic elongation factor 2 (eEF2) has certain clinical values for early diagnosis, verification, and prognosis as well as classification of lung cancer patients.

MBOD법에 의한 낙동강의 조류증식 제한인자 추정 (Evaluation of Algal Growth Limiting Factor in the Nakdong River by MBOD Method)

  • 송교욱;서인숙
    • 한국환경과학회지
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    • 제4권5호
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    • pp.469-479
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    • 1995
  • The increase of population and industrial activities had brought into eutrophication in the Nakdong river. A remarkable acceleration of eutrophication brought about serious problems for water supply. Therefore, for the purpose of conservation of water quality in the Nakdong river it is necessary to control nutrients. MBOD method was use to evaluate algal growth limiting factor and algal growth potential in the Nakdong river from June to August 1994. The modified biochemical oxygen demand(MBOD) depends on the amount of available inorganic nutrient and organic substrate during 5 day incubation in the dark at 2$0^{\circ}C$. The MBOD assay depends on inorganic nutrients such as P and N as well as reduced carbon and called the MBOD, the MBOD-P, and the MBOD-N, respectively. The results of bioassay by MBOD(Modified BOD) method showed that the MBOD, MBOD-P and MBOD-N value were found to be in the ranges of 3.8~96.0 mg$O_2$/l, 5.6~94.0 mg$O_2$/l and 42.0~220 mg$O_2$/l, respectively. And the the bioassay value was found to be the highest in Koryong area and the lowest in Waekwan area throughout the Nakdong river. The variations of MBOD-P and MBOD-N value showed similar tendencies to the variations of phosphorus and nitrogen value, respectively. By MBOD method, the relationships of MBOD, MBOD-P and MBOD-N value were MBOD ≒ MBOD-P 《 MBOD-N. The MBOD value was nearly equal to the MBOD-P value, and the MBOD-N value was 3 to 20 times more than the MBOD-P value, approximately. Therefore, in the Nakdong river, phosphorus was the limiting factor for algal growth during summer season. The algal growth potential as the concentration of chlorophyll-a in the summer was maximum 5 times more than standing crop as it.

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변분 베이지안 혼합 인자 분석에 의한 분포 추정을 이용하는 진화 알고리즘 (Evolutionary Algorithms with Distribution Estimation by Variational Bayesian Mixtures of Factor Analyzers)

  • 조동연;장병탁
    • 한국정보과학회논문지:소프트웨어및응용
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    • 제32권11호
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    • pp.1071-1083
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    • 2005
  • 최근 들어 확률 분포를 개체군으로부터 추정하여 보다 효율적으로 최적화를 해결하려는 연구가 진행되고 있다. 특히 복잡한 문제의 해결을 위해서 혼합 분포가 사용되고 있다. 그러나 이 경우 몇 개의 성분으로 혼합 분포를 나타낼 것인가를 결정하기 어려운 문제가 있으며, 각 분포에 의하여 표현되는 이전 세대의 우수한 부분 해들을 잘 결합하지 못하는 단점이 있다. 본 논문에서는 변분 베이지안 혼합 인자 분석(variational Bayesian mixtures of factor analyzers) 기법을 사용한 개체군의 분포 추정을 통해 실수 공간에서의 최적화 문제를 해결하는 방법을 제안한다. 이 기법은 혼합 분포의 개수 추정을 자동화하며, 잠재 변수(latent variable)를 사용하여 각 분포가 표현하는 세부 개체군 내에 포함된 부분 해들의 혼합을 효율적으로 수행할 수 있다. 잘 알려진 함수 최적화 문제들에 대해 다른 분포 추정 진화 알고리즘과 비교하여 제안하는 방법의 우수성을 검증하였다. 또한 시스템 생물학에서 다루고 있는 생화학 네트워크의 동적 모델링을 위한 매개변수 추정도 성공적으로 수행하였다.