• Title/Summary/Keyword: Biological spectrum

Search Result 469, Processing Time 0.02 seconds

Spectral Analysis of the Horizontal Saccadic Eye Movement (수평 Saccadic 안구운동의 스펙트럼 분석에 관한 연구)

  • 김남균
    • Journal of Biomedical Engineering Research
    • /
    • v.13 no.1
    • /
    • pp.65-68
    • /
    • 1992
  • In the present study, an attempt is presented to define the power spectrum of the saccades recorded in man by using bitemporal EOG. In this study, it was found that the estimated bandwidth of the spectrum of the saccades decreases for increasing saccade amplitude. This study could show a reference value about the minimum bandwidth needed to correctly measure even small saccades by bitemporal EOG. It also showed that EOG method is not appropriate to measure microsaccade.

  • PDF

Electro-optical Characteristics of the Degraded Functional Layer in an Alternating- Current Plasma Display Panel

  • Lee, Kyung Ae;Min, Booki;Son, Chang Gil;Byeon, Yong S.;Yoon, Sang Ho;Choi, Eun Ha
    • Applied Science and Convergence Technology
    • /
    • v.24 no.6
    • /
    • pp.232-236
    • /
    • 2015
  • The electro-optical characteristics of several functional layers over the MgO protective layer were studied during the continuous discharge of an AC-PDP. In order to observe the degradation of each functional layer on the MgO protection layer, we measured the surface morphology, cathodoluminescence (CL) spectrum, the secondary electron emission coefficient (${\gamma}$) and the discharge characteristics after 500 hours of discharge during the operation of the AC-PDP.

Structural Insights for β-Lactam Antibiotics

  • Dogyeoung, Kim;Sumin, Kim;Yongdae, Kwon;Yeseul, Kim;Hyunjae, Park;Kiwoong, Kwak;Hyeonmin, Lee;Jung Hun, Lee;Kyung-Min, Jang;Donghak, Kim;Sang Hee, Lee;Lin-Woo, Kang
    • Biomolecules & Therapeutics
    • /
    • v.31 no.2
    • /
    • pp.141-147
    • /
    • 2023
  • Antibiotic resistance has emerged as a global threat to modern healthcare systems and has nullified many commonly used antibiotics. β-Lactam antibiotics are among the most successful and occupy approximately two-thirds of the prescription antibiotic market. They inhibit the synthesis of the peptidoglycan layer in the bacterial cell wall by mimicking the D-Ala-D-Ala in the pentapeptide crosslinking neighboring glycan chains. To date, various β-lactam antibiotics have been developed to increase the spectrum of activity and evade drug resistance. This review emphasizes the three-dimensional structural characteristics of β-lactam antibiotics regarding the overall scaffold, working mechanism, chemical diversity, and hydrolysis mechanism by β-lactamases. The structural insight into various β-lactams will provide an in-depth understanding of the antibacterial efficacy and susceptibility to drug resistance in multidrug-resistant bacteria and help to develop better β-lactam antibiotics and inhibitors.

On-line Magnetic Resonance Quality Evaluation Sensor

  • Kim, Seong-Min;McCarthy, Michael J.;Chen, Pictiaw;Zion, Boaz
    • Proceedings of the Korean Society for Agricultural Machinery Conference
    • /
    • 1996.06c
    • /
    • pp.314-324
    • /
    • 1996
  • A high speed NMR quality evaluation sensor was designed , constructed and tested . The device consists of an NMR spectrometer coupled to a conveyor system. The conveyor was run at speeds ranging from 0 to 250 mm/s. Spectral of avocado fruits and one-dimensional magnetic resonance images of pickled olives were acquired while the samples were moving on a conveyor belt mounted through a 20Tesla NMR magnet with a 20 mm diameter surface coil and a 150 mm diameter imaging coil respectively. Fro a magnetic resonance spectrum analysis, motion through variations in the magnetic field tends to narrow spectral line width just like using sample rotation in high resolution NMR to narrow spectral line width. Spectrum analysis was used to detect the dry weight of avocado fruits using the ratio oil and water resonance peaks. Good correlations maximum r=0.970@ 50 mm/s and minimum r=0.894@250mm/s ) between oil and water resonance peak ratio and dry weight of avocados were observed at speeds ra ging from0 to 250mm/s. For the application of magnetic resonance imaging (MRI) method, the projections were used to distinguish between pitted and non-pitted olives . Effect of fruit position in the coil was tested and coil degree effects were noticed when projects were generated under dynamic conditions. Various belt speeds (up to 250mm/s) were tested and detection results were compared to static measurements. Higher classification errors were occurred at dynamic conditions compared to errors while olives were at rest.

  • PDF

Isolation and Structural Determination of Antifungal Antibiotic from Streptomyces hygroscopicus MJM1004 (Streptomyces hygroscopicus MJM1004가 생산하는 항진균성 항생 물질의 분리 및 구조 결정)

  • Bae, Ju-Yun;Kwon, Hyong-Jin;Suh, Joo-Won
    • Applied Biological Chemistry
    • /
    • v.42 no.4
    • /
    • pp.271-276
    • /
    • 1999
  • Several Streptomyces strains were tested for potent antifungal agents active against phytopathogenic fungi. Among the tested, S. hygroscopicus MJM1004 showed a potent antifungal activity when assayed using Candida albicans as indicator organism. With the strain of MJM1004, fermentation medium for the production of an antifungal agent was developed with varying carbon sources, nitrogen sources, and mineral elements, which resulted in the highest productivity in the medium containing 2% soybean meal, 1% glucose, 2% starch, 0.3% $CaCO_3$, 0.05% $MgSO_4{\cdot}7H_2O$, 0.05% $K_2HPO_4$. The active compound showed a broad spectrum of antifungal activity against several plant pathogenic fungi. The antifungal compound was purified and showed the physicochemical characteristics similar to azalomycin F complex in NMR and MS analysis.

  • PDF

Introduction of the Concept of Social Dysfunction Spectrum (사회기능부전스펙트럼 개념의 도입)

  • Bahn, Geon Ho;Lee, Yeon Jung;Han, Juhee
    • Korean Journal of Biological Psychiatry
    • /
    • v.21 no.4
    • /
    • pp.118-127
    • /
    • 2014
  • Along with language, socialization is a unique feature of the human being. There is a continuous debate regarding whether the development of socialization is innate, and conducted by the environment in the growing process, or the result of the interaction of both aspects. If socialization is the result of the interaction with the environment or is an acquired developmental process, the following question rises. "Is there a 'critical period' for the development of socialization?" Although there are a huge number of studies seeking for treatment and solutions for developmental delay or deficits of socialization, it is very complicated question to answer. Historical figures such as 'Hugh Blair' of Borgue in England, and 'the wild boy of Aveyron' in France, seem to have innate socialization deficits. Nowadays patients with non-verbal learning disorder, social communication disorder, or autism spectrum disorder seem to have genetic defects. On the other hand, Harry Harlow's monkey experiments, hikikomori of Japan, Romanian orphans and patients with reactive attachment disorder seem to display social deficits due to environmental factors. However, it is not easy to clearly draw a line between innate or acquired factors. Therefore, rather than subdividing the diseases for etiological and pathophysiological approach to heterogenous groups with the common denominator of social deficit, and for the research of pathophysiology and treatment development, the authors suggest a comprehensive concept of "social dysfunction spectrum."

Estimation of Visual Evoked Potentials Using Time-Frequency Analysis (시-주파수 분석법을 이용한 시각자극 유발전위에 관한 연구)

  • 홍석균;성홍모;윤영로;윤형로
    • Journal of Biomedical Engineering Research
    • /
    • v.22 no.3
    • /
    • pp.259-267
    • /
    • 2001
  • The visual evoked potentials(VEPs) is used to assist in the diagnosis of specific disorders associated with involvement of the sensory visual pathways. The P100 latency is an important parameter which is diagnosis of optic nerve disorders. There are characteristics of latency delay, wave distortion, amplitude deduction in abnormal subjects. It is difficult to diagnose in the case of producing peak at the P100 latency. In this paper, difference of pattern between normal VEPs and abnormal VEPs using the Choi-Williams distribution method is studied. We observed the relationship about time and spectrum. The result shown that normal VEPs had maximum spectral value at 20Hz~26.7Hz and abnormal VEPs had maximum spectral value at 16.7Hz~20Hz. Also normal VEPs spectrum is higher than abnormal VEPs spectrum.

  • PDF

The Estimation of the Depth of Anesthetic Using Higher-Order Spectrum Analysis of EEG Signals

  • Park, Jong-Duk;Ye, Soo-Young;Jeon, Gye-Rok;Huh, Young
    • Journal of Biomedical Engineering Research
    • /
    • v.28 no.2
    • /
    • pp.287-293
    • /
    • 2007
  • The researchers have studied for a long time about the depth of anesthesia but they don't make criteria for the depth of anesthesia. Anesthetists can't make a prediction about patient's reaction. Therefore, patients have potential risk such as poisonous side effect, late-awake, early-awake and strain reaction. In this study, the distributed characteristics on the bispectrum and bicoherence, the type of nonlinear signal processing, as a result of the coupling of EEG were presented according to depth of anesthesia. These results were consistent with a trend of delta ratio that the index of evaluation for the depth of anesthesia. The higher-order spectrum (HOS), the bispectrum and bicoherence, gives the useful information about depth of anaesthesia than other indexes.

Development of EGG measurement system with running spectrum analysis (위전도 측정기의 개발 및 스펙트럼 분석)

  • Ryu, Chang-Yong;Kim, Su-Chan;Kim, Deok-Won;Lee, Sang-In
    • Proceedings of the KOSOMBE Conference
    • /
    • v.1995 no.11
    • /
    • pp.82-85
    • /
    • 1995
  • Electrogastrography(EGG) has been an attractive method for physiological and pathophysiological studies of the stomach and now is on the verge of becoming a new clinical tool in gastroenterology. In this study EGG measurement system was constructed and running spectrum analysis was developed for three-dimensional display of power spectrum with time. The noninvasive technique of EGG is an excellent alternative since the established invasive methods for the study of the stomachs of children and infants.

  • PDF