• 제목/요약/키워드: Onset Potential

검색결과 288건 처리시간 0.026초

치매에 관한 최근의 연구 동향 (The latest development in Dementia)

  • 나창수;김정상;채우석;박석천
    • 대한한방내과학회지
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    • 제19권1호
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    • pp.291-300
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    • 1998
  • Dementia is the neurodegenerative process that affects cognition, behavior and function and one of the most prominent diseases of dementia is Alzheimer's disease(AD). AD is a dementing illness characterized clinically by the progressive and irreversible deafferentation of the limbic system, association neocortex and basal forebrain. A number of conditions are known to be predisposing risk factors for AD. In several of these, initiation of glial-mediated inflammatory pathways as a mechanism of AD is getting a lot of attention. On the other hand, a biochemical marker for monitoring the onset and progression of the disease would be a valuable tool for disease management. Also such a marker might be used as an end point in clinical intervention protocols. This biochemical marker will have the potential for identifying subjects afflicted with the disease and possibly for monitoring the onset and longitudinal progression of the disease. Here we have reviewed the latest papers of different approaches to AD. Of course, there is a section of PET which is very useful clinically nowadays.

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Acute-onset chronic inflammatory demyelinating polyneuropathy following hepatitis A virus infection

  • Jung, Eui Sung;Kim, Ye Sel;Min, Ju-Hong;Kang, Kyusik;Lee, Jung Ju;Park, Jong-Moo;Kim, Byung-Kun;Kwon, Ohyun
    • Annals of Clinical Neurophysiology
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    • 제19권1호
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    • pp.50-53
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    • 2017
  • An infection is less likely to elicit chronic inflammatory demyelinating polyneuropathy (CIDP) than Guillain-$Barr{\acute{e}}$ syndrome. We here report a case of acute-onset CIDP following hepatitis A virus infection and briefly comment on the potential mechanisms regarding the induction and chronicity of autoimmunity after a viral infection.

혼성 유체-입자(몬테칼로)법을 이용한 유사스파크 방전의 기동 특성 해석 (Analysis on the lgnition Charac teristics of Pseudospark Discharge Using Hybrid Fluid-Particle(Monte Carlo) Method)

  • 심재학;주홍진;강형부
    • 한국전기전자재료학회논문지
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    • 제11권7호
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    • pp.571-580
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    • 1998
  • The numerical model that can describe the ignition of pseudospark discharge using hybrid fluid-particle(Monte Carlo )method has been developed. This model consists of the fluid expression for transport of electrons and ions and Poisson's equation in the electric field. The fluid equation determines the spatiotemporal dependence of charged particle densities and the ionization source term is computed using the Monte carlo method. This model has been used to study the evolution of a discharge in Argon at 0.5 torr, with an applied voltage if 1kV. The evolution process of the discharge has been divided into four phases along the potential distribution : (1) Townsend discharge, (2) plasma formation, (3) onset of hollow cathode effect, (4) plasma expansion. From the numerical results, the physical mechanisms that lead to the rapid rise in current associated with the onset of pseudospark could be identified.

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Application of CRISPR-Cas9 gene editing for congenital heart disease

  • Seok, Heeyoung;Deng, Rui;Cowan, Douglas B.;Wang, Da-Zhi
    • Clinical and Experimental Pediatrics
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    • 제64권6호
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    • pp.269-279
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    • 2021
  • Clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9 (CRISPR-Cas9) is an ancient prokaryotic defense system that precisely cuts foreign genomic DNA under the control of a small number of guide RNAs. The CRISPR-Cas9 system facilitates efficient double-stranded DNA cleavage that has been recently adopted for genome editing to create or correct inherited genetic mutations causing disease. Congenital heart disease (CHD) is generally caused by genetic mutations such as base substitutions, deletions, and insertions, which result in diverse developmental defects and remains a leading cause of birth defects. Pediatric CHD patients exhibit a spectrum of cardiac abnormalities such as septal defects, valvular defects, and abnormal chamber development. CHD onset occurs during the prenatal period and often results in early lethality during childhood. Because CRISPR-Cas9-based genome editing technology has gained considerable attention for its potential to prevent and treat diseases, we will review the CRISPR-Cas9 system as a genome editing tool and focus on its therapeutic application for CHD.

Study of thermoacoustic oscillations in half-open tubes for saturated superfluid helium

  • Wang, Xianjin;Niu, Xiaofei;Bai, Feng;Zhang, Junhui;Chen, Shuping
    • 한국초전도ㆍ저온공학회논문지
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    • 제24권3호
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    • pp.68-73
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    • 2022
  • Thermoacoustic oscillations (TAOs) are spontaneous pressure oscillations frequently seen in hydrogen or helium cryogenic systems. Half-open tubes connected to cryogenic fluid with a closed room temperature end have a high potential for oscillation generation. Thermoacoustic oscillations will result in significant pressure fluctuations and additional heat load, endangering the security and stability of the cryogenic system. The goal of this paper is to investigate TAOs in superfluid helium using both theoretical and experimental methods. Five half-open tubes with varied typical inner diameters inserted into superfluid helium were installed in a test cryostat. The onset characteristics of thermoacoustic oscillations were presented and studied. The effect of temperature profile was discussed. Finally, a simple eliminating method was introduced.

현재와 미래의 북반구 눈피복 변화와 대기순환과의 잠재적인 상관성 (Current and Future Changes in Northern Hemisphere Snow Extent and Their Potential Linkages with Atmospheric Circulation)

  • 최광용;김준수;데이비드라빈슨
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2008년도 학술발표회 논문집
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    • pp.294-298
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    • 2008
  • Snow cover is a potential water resource for later spring and summer seasons as well as a thermal mirror with high reflectivity causing decreases of surface air temperature during cold winter seasons. In this study, current and future changes in Northern Hemisphere snow extent and their potential linkages with atmospheric circulation are examined. The NOAA AVHRR visible snow extent (1967-2006) data as well as observational (NCEP-DOE 1979-2006) and modeled (GFDL 2.1 2081-2100) pressure and surface air temperature data are used. Analyses of observational data demonstrate that the snow extent in meteorological spring (March to April) and summer (June to August) has significantly decreased since the late 1980s. The offset of snow seasons (the timing of snow melt in spring) have also significantly advanced particularly in Europe, East Asia, and northwestern North America. Analyses of pressure fields reveal that the spatial patterns of the earlier snow melt are associated with changes in atmospheric circulation such as the Arctic Oscillation (AO). In the positive winter AO years, multiple positive pressure departure cores in the upper troposphere (200hPa) are observed over the mid-latitude regions from March to mid-April, while a negative pressure departure core (70hPa) prevails over the Arctic Ocean. The reversed anomaly patterns related to later snow melt occur in negative winter AO years. The comparison between current and future thermal spring onsets suggest that snow melt patterns will intensify with larger greenhouse gas emissions, indicating earlier hydrological spring onset.

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The SOCS-1 -1478CA/del Polymorphism is not Associated with Colorectal Cancer or Age at Onset in Turkish Subjects

  • Hartavi, Mustafa;Kurt, Ender;Oral, Barbaros;Olmez, Omer Fatih;Cubukcu, Erdem;Deligonul, Adem;Avci, Nilufer;Manavoglu, Osman
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권12호
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    • pp.7583-7586
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    • 2013
  • Background: Suppressor of cytokine signaling (SOCS)-1 acts as a key regulator of many cytokine signaling pathways and its abnormal expression has been identified in several human malignancies, suggesting potential roles in carcinogenesis. The aim of this study was to investigate any association between the functional SOCS-1 -1478CA>del polymorphism and colorectal cancer (CC) as well as age at onset in a Turkish clinical sample. Materials and Methods: A total of 122 subjects were enrolled in this case-control study (70 CC cases and 52 controls). The SOCS-1 -1478CA>del polymorphism was genotyped using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Results: The odds ratio of the del allele for CC relative to the CA allele was not significantly different between the groups (OR=0.71, 95% CI=0.41-1.22, p=0.27). This result did not change after adjustment for age and sex on multivariable regression analysis (OR=0.84, 95% CI=0.59-1.34, p=0.53). When the SOCS-1 -1478CA>del polymorphism was analyzed among CC patients in relation to the age at disease onset, we found no significant differences between subjects with the del/del, CA/del, and CA/CA genotypes. Conclusions: The results of our study did not point towards a major role of the SOCS-1 -1478CA>del polymorphism in the pathogenesis of CC in Turkish subjects.

뇌졸중 환자에서 운동단위의 초기 방전 양상 (Initial Motor Unit Discharge Pattern in Patients with Stroke)

  • 이상무;배재천
    • Annals of Clinical Neurophysiology
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    • 제4권1호
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    • pp.12-15
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    • 2002
  • Background : Changes in firing pattern and in the recruitment order of single motor unit(MU) have been claimed to be characteristic of central motor lesions, and a reduced firing rate was found in upper motor neuron lesions. But these findings have been rarely studied before in Korea, so we studied initial MU recruitment pattern in stroke patients with hemiparesis. Methods : We studied six patients(3 men and 3 women) whose mean age was $60.6{\pm}7.4$ years. A mean $20.6{\pm}16.2$ months had elapsed since the stroke. To compare the initial MU activation patterns in proximal and distal segments of paretic limb with their contalateral unaffected counterparts, we studied the onset and recruitment intervals in biceps brachii(BB) and first dorsal interossei(FDI) muscles in paretic and healthy arms. In a single muscle we examined from 5 to 10 individual MUs. And in a single motor unit, both the onset interval and the recruitment interval was examined. Results : The mean onset interval in paretic limb was significantly(p<0.05) longer than unaffected limb at proximal and distal location: BB $118.5{\pm}17.8$ msec vs $96.1{\pm}8.3$ msec(n=58); FDI $125.8{\pm}16.7$ msec vs $101.5{\pm}17.2$ msec(n=38). The mean recruitment interval in paretic limb was also significantly(p<0.05) longer than unaffected limb: BB $87.7{\pm}14.9$ msec vs $73.4{\pm}11.5$ msec(n=53); FDI $96.3{\pm}16.4$ msec vs $87.7{\pm}14.1$ msec(n=38). Conclusion : The first recruited MU had a lower baseline firing rate and the second recruited motor unit potential appeared earlier in paretic than in healthy muscles. And these findings may explain one of the reasons for paresis in patients with stroke.

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Buffered versus unbuffered local anesthesia for inferior alveolar nerve block injections in children: a systematic review

  • Tirupathi, Sunny Priyatham;Rajasekhar, Srinitya
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제20권5호
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    • pp.271-279
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    • 2020
  • Background: The present study aimed to evaluate and compare the efficacy of buffered and unbuffered local anesthesia solutions during inferior alveolar nerve block (IANB) administration in children. Methods: PubMed, Ovid SP, and Cochrane databases were searched separately by two independent reviewers for potential papers published between 1980 and April 2020 using relevant MeSH terms and pre-specified inclusion and exclusion criteria. T Studies of IANB administration in children comparing buffered and unbuffered local anesthesia solutions were evaluated. The primary outcome evaluated was pain (perception and reaction), while the secondary outcome was the onset of anesthesia. Results: A total of five articles were included in a qualitative analysis; among them, four qualified for quantitative analysis of the primary outcome and three for quantitative analysis of the secondary outcome. A fixed-effects model was used to perform the meta-analysis. Pain perception (child-reported pain): Significantly lower pain scores were reported with buffered local anesthesia solution than with unbuffered solution (P = 0.006, MD: -0.32, 95% CI: -0.55 to -0.09). Pain reaction (observer-reported pain reaction in child): No significant difference was found between buffered and unbuffered solution in terms of observer-reported pain behavior in the child (P = 0.09, MD: -0.21, 95% CI: -0.46 to 0.04). Onset of anesthesia: A significantly lower duration of anesthesia onset was reported with buffered local anesthesia solution than with unbuffered solution (P = 0.00001, MD: -12.38, 95% CI: -17.64 to -7.13]. Conclusion: Buffering local anesthesia solution may reduce discomfort due to IANB injection administration and lower the initial onset time of anesthesia. More randomized control trials with adequate sample sizes should be carried out to validate the accuracy of these results.

새로운 우울증 치료 약물 (Novel Pharmacological Treatment for Depression)

  • 정희정;문은수
    • 생물정신의학
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    • 제23권1호
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    • pp.1-11
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    • 2016
  • Development of various antidepressants such as monoamine oxidase inhibitors, tricyclic antidepressants, selective serotonin reuptake inhibitors, serotonin norepinephrine reuptake inhibitors, and noradrenergic and specific serotonergic antidepressant has led to a tremendous progression of pharmaceutical treatment for depression, but still there are some limitations of current antidepressants, such as treatment-resistant depression and delayed onset of antidepressants. The pathogenesis of depression is unclear because depression is a heterogeneous disease state, and the mechanisms of antidepressants remain uncertain as well. Nevertheless, in an attempt to develop novel antidepressants, some trials have been conducted based on the potential biological mechanism discovered in the numerous research results. This review will provide information about the potential novel antidepressants and the current states of clinical studies using them. In particular, some potential novel antidepressants anti-inflammatory agents, antioxidants, anticholinergics, modulators of Hypothalamic Pituitary Adrenal Axis, glutamate, and opioid systems, as well as some neuropeptides such as susbstance P, neuropeptide Y, and galanin will be discussed.